Sample records for bullhead city az

  1. 78 FR 34300 - Safety Zone; Bullhead City Regatta, Bullhead City, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-07

    ...USCG-2013-0260] RIN 1625-AA00 Safety Zone; Bullhead City Regatta, Bullhead City, AZ AGENCY: Coast Guard, DHS. ACTION: Notice...navigable waters of the Colorado River in Bullhead City, Arizona for the Bullhead City Regatta on...

  2. 78 FR 71706 - Noise Exposure Map Notice for Laughlin/Bullhead International Airport, Bullhead City, Arizona

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-29

    ...Aviation Administration Noise Exposure Map Notice for Laughlin/Bullhead International...its determination that the noise exposure maps submitted by Mohave County Airport Authority...that the FAA finds that the noise exposure maps submitted for Laughlin/Bullhead...

  3. 33 CFR 100.1102 - Annual marine events on the Colorado River, between Davis Dam (Bullhead City, Arizona) and...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Annual marine events on the Colorado River, between Davis Dam (Bullhead City... Annual marine events on the Colorado River, between Davis Dam (Bullhead City...Area That portion of the lower Colorado River on the Arizona side between Thompson...

  4. 33 CFR 100.1102 - Marine Events on the Colorado River, between Davis Dam (Bullhead City, Arizona) and Headgate Dam...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... false Marine Events on the Colorado River, between Davis Dam (Bullhead City...1102 Marine Events on the Colorado River, between Davis Dam (Bullhead City...Lake Moovalya, Parker, Arizona between river miles 179 and 185 (between the...

  5. 33 CFR 100.1102 - Annual marine events on the Colorado River, between Davis Dam (Bullhead City, Arizona) and...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Annual marine events on the Colorado River, between Davis Dam (Bullhead City... Annual marine events on the Colorado River, between Davis Dam (Bullhead City...Area That portion of the lower Colorado River on the Arizona side between Thompson...

  6. 33 CFR 165.1124 - Annual Firework Events on the Colorado River, between Davis Dam (Bullhead City, Arizona) and...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Annual Firework Events on the Colorado River, between Davis Dam (Bullhead City... Annual Firework Events on the Colorado River, between Davis Dam (Bullhead City...Location Laughlin, NV. Regulated Area River closure from 8pm-10pm. The safety...

  7. 33 CFR 165.1124 - Annual Firework Events on the Colorado River, between Davis Dam (Bullhead City, Arizona) and...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Annual Firework Events on the Colorado River, between Davis Dam (Bullhead City... Annual Firework Events on the Colorado River, between Davis Dam (Bullhead City...Location Laughlin, NV. Regulated Area River closure from 8pm-10pm. The safety...

  8. 33 CFR 100.1102 - Annual Marine Events on the Colorado River, between Davis Dam (Bullhead City, Arizona) and...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Annual Marine Events on the Colorado River, between Davis Dam (Bullhead City... Annual Marine Events on the Colorado River, between Davis Dam (Bullhead City...Area That portion of the lower Colorado River on the Arizona side between Thompson...

  9. 33 CFR 100.1102 - Marine Events on the Colorado River, between Davis Dam (Bullhead City, Arizona) and Headgate Dam...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... false Marine Events on the Colorado River, between Davis Dam (Bullhead City...1102 Marine Events on the Colorado River, between Davis Dam (Bullhead City...Lake Moovalya, Parker, Arizona between river miles 179 and 185 (between the...

  10. 33 CFR 165.1124 - Annual Firework Events on the Colorado River, between Davis Dam (Bullhead City, Arizona) and...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Annual Firework Events on the Colorado River, between Davis Dam (Bullhead City... Annual Firework Events on the Colorado River, between Davis Dam (Bullhead City...Location Laughlin, NV. Regulated Area River closure from 8 p.m.-10 p.m....

  11. 77 FR 36439 - Safety Zone; Bullhead City Regatta; Bullhead City, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-19

    ...the entire width of the river, traffic would be allowed...and 160.5; Public Law 107-295, 116 Stat...includes the waters of the Colorado River between Davis Camp and...local, state, and federal law enforcement vessels...

  12. 76 FR 38568 - Safety Zone; Bullhead City Regatta, Bullhead City, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-01

    ...the waters of the Colorado River between Davis Camp...either preempt State law or impose a substantial...with applicable law or otherwise impractical...the waters of the Colorado River between Davis Camp...state, and Federal law enforcement...

  13. 78 FR 44011 - Safety Zone; Bullhead City Regatta; Bullhead City, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-23

    ...waters of the Colorado River between Davis Camp to Rotary...the entire width of the river, traffic would be allowed...includes the waters of the Colorado River between Davis Camp and...local, state, and federal law enforcement vessels...

  14. 77 FR 70121 - Special Local Regulation; Annual Marine Events on the Colorado River Between Davis Dam (Bullhead...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-23

    ...Special Local Regulation; Annual Marine Events on the Colorado River Between Davis Dam (Bullhead City, AZ) and Headgate...Guard may be assisted by other Federal, State, or local law enforcement agencies in enforcing this regulation....

  15. 77 FR 67563 - Special Local Regulation; Annual Marine Events on the Colorado River, Between Davis Dam (Bullhead...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-13

    ...Special Local Regulation; Annual Marine Events on the Colorado River, Between Davis Dam (Bullhead City, AZ) and Headgate...Guard may be assisted by other Federal, State, or local law enforcement agencies in enforcing this regulation....

  16. 78 FR 16823 - Proposed Establishment of Class E Airspace; Tuba City, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-19

    ...Navigational Aid (VORTAC), Tuba City, AZ to facilitate vectoring of...control of Denver, Albuquerque and Salt Lake City Air Route Traffic Control Centers...control of Denver, Albuquerque and Salt Lake City ARTCCs by vectoring aircraft...

  17. 78 FR 32086 - Establishment of Class E Airspace; Tuba City, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-29

    ...Navigational Aid (VORTAC), Tuba City, AZ, to facilitate vectoring of...control of Denver, Albuquerque and Salt Lake City Air Route Traffic Control Centers...control of Denver, Albuquerque and Salt Lake City ARTCCs by vectoring aircraft...

  18. Food Habits and Diet Selectivity of the Brown Bullhead

    Microsoft Academic Search

    Jeffrey L. Kline; Brian M. Wood

    1996-01-01

    Food habits of the brown bullhead Ameiurus nebulosus were investigated in June and July 1994 in Perch Lake, Jefferson County, New York to determine feeding selectivity. Twenty-seven prey taxa were identified from 39 brown bullhead (total length, 29–330 mm). Chironomid larvae and pupae constituted the greatest portion of the diet by number of die young of the year brown bullhead

  19. Regulation of the black bullhead hepatic ?-adrenoceptors

    Microsoft Academic Search

    Stephen G. Dugan; Xi Chen; James G. Nickerson; Colin J. Montpetit; Thomas W. Moon

    2008-01-01

    Black bullhead catfish (Ameiurus melas) were exposed to air for 1 h to examine the effect of an acute stress on the distribution and function of the hepatic ?-adrenoceptors (?-ARs). Air exposure significantly reduced both adrenaline (ADR)- and noradrenaline (NADR)-stimulated glucose production in isolated hepatocytes with no effect on either receptor affinity (Kd) or number of binding sites (Bmax). A 24 h

  20. 78 FR 60698 - Safety Zone, Lucas Oil Drag Boat Racing Series; Thompson Bay, Lake Havasu City, AZ.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-02

    ...RIN 1625-AA00 Safety Zone, Lucas Oil Drag Boat Racing Series; Thompson Bay, Lake...Bay in Lake Havasu, AZ for the Lucas Oil Drag Boat Racing Series. This temporary safety...the logistical details of the Lucas Oil Drag Boat Racing Series were not finalized...

  1. Habitat Suitability Index Models: Black Bullhead

    USGS Publications Warehouse

    Stuber, Robert J.

    1982-01-01

    This is one of a series of publications that provide information on the habitat requirements of selected fish and wildlife species. Literature describing the relationship between habitat variables related to life requisites and habitat suitability for the Black bullhead (Ictalurus melas) are synthesized. These data are subsequently used to develop Habitat Suitability (HIS) models. The HSI models are designed to provide information that can be used in impact assessment and habitat management.

  2. Nightlife A-Z

    NSDL National Science Digital Library

    Nightlife A-Z provides links to entertainment, shopping, and hotel directories for cities from Akron to Zurich. Handy if you're planning to visit any of these 130 cities in the U.S., Europe, or Asia. Provided by ENN (Entertainment Network News), the site also offers the latest entertainment news and an index to movies, kids links, comedy clubs, coffee pages, among many others. Proceeds from page sponsors go to the National Children's Coalition. http://www.sftoday.com/enn2/nitelife.htm

  3. HISTORICAL MONITORING OF BIOMARKERS OF EXPOSURE OF BROWN BULLHEAD

    EPA Science Inventory

    Biomarkers of exposure to chemical contamination, benzo(a)pyrene (BAP) and naphthalene (NAPH) type metabolites were measured in brown bullhead from a heavily polycyclic aromatic hydrocarbon (PAH) contaminated section of the Black River, Ohio during and immediately after remedial ...

  4. Metabolism of phenanthrene by brown bullhead liver microsomes.

    PubMed

    Pangrekar, Jyotsna; Kole, Panna L; Honey, Sangeet A; Kumar, Subodh; Sikka, Harish C

    2003-09-10

    We have investigated the regio- and stereoselective metabolism of phenanthrene by the liver microsomes of brown bullhead (Ameriurus nebulosus), a bottom dwelling fish species. The liver microsomes from untreated and 3-methylcholanthrene (3-MC)-treated brown bullheads metabolized phenanthrene at a rate of 14.1 and 20.7 pmol/mg protein/min, respectively, indicating that the hydrocarbon is a rather poor substrate for bullhead liver microsomes contrary to what has been reported for rat liver microsomes. The major phenanthrene metabolites formed by liver microsomes from untreated and 3-MC-treated bullheads included benzo-ring 1,2-dihydrodiol (25.3 and 11.6%), K-region 9,10-dihydrodiol (9.6 and 9.6%), and phenols (40.5 and 54.5%). The 3,4-dihydrodiol represented a minor proportion of the total phenanthrene metabolites. The low proportion of the 9,10-dihydrodiol formed by both control and 3-MC-treated bullhead microsomes sharply contrasts the previous data reported for the corresponding rat liver microsomes which metabolized phenanthrene predominantly to its 9,10-dihydrodiol representing 76.6 and 67.1%, respectively of the total metabolites. Liver microsomes from 3-MC-treated bullheads, like rat liver microsomes, were more selective in their attack at the 1,2-position of the benzo-ring than at the 3,4-position of the benzo-ring. Phenanthrene 1,2-dihydrodiol and 3,4-dihydrodiol formed by liver microsomes from both control and 3-MC-treated bullheads consisted predominantly of their R,R enantiomer. Phenanthrene, compared with benzo[a]pyrene and chrysene, is metabolized by bullhead liver microsomal enzymes to its benzo-ring dihydrodiols with a relatively low degree of stereoselectivity. PMID:12878411

  5. DNA DAMAGE AND EXTERNAL LESIONS IN BROWN BULLHEAD FROM CONTAMINATED HABITATS

    EPA Science Inventory

    The single cell gel electrophoresis ("Comet") assay was used to compare levels of DNA damage in brown bullheads (Ameiurus nebulosus) collected from three known contaminated locations, the Cuyahoga River, Ashtabula River, and Ashumet Pond (Cape Cod), with brown bullheads collected...

  6. Black Bullhead Growth in South Dakota Waters: Limnological and Community Influences

    Microsoft Academic Search

    Patrick A. Hanchin; David W. Willis; Matthew J. Hubers

    2002-01-01

    Growth was determined for 35 black bullhead (Ameiurus melas) populations in eastern South Dakota lakes. Black bullhead growth was highly variable among populations. Average mean lengths at ages 1–6 for all populations were 101, 155, 203, 232, 262, and 289 mm, respectively. Few populations contained fish older than age 6. Growth was negatively associated with black bullhead abundance, and positively

  7. Biotic and Abiotic Correlates with Black Bullhead Population Characteristics in Nebraska Sandhill Lakes

    Microsoft Academic Search

    Quinton E. Phelps; Matthew J. Ward; Craig P. Paukert; Steven R. Chipps; David W. Willis

    2005-01-01

    We explored relationships among black bullhead (Ameiurus melas) population characteristics and physicochemical attributes in shallow lakes and quantified relationships between population characteristics of black bullhead and sport fishes. Lake characteristics and fisheries survey data were collected from the Sandhills region of northcentral Nebraska from May through June, 1998 and 1999. Relative abundance of black bullheads was inversely related to proportional

  8. INITIAL AND SURVIVAL OF BlUEGILLS AND BLACK BULLHEADS STOCKED WITH LARGEMOUTH BASS

    E-print Network

    estimated for bluegills (Lepomis macrochirus) and black bullheads (Ictalurus melas) stocked simultaneously (Lepomis macrochirus) and black bullhead (Ictalurus melas) first year growth mUltiple regression tests · · . · . 2. Mean first year survival rates of bluegills (Lepomis macrochirus) and black bullheads (Ictalurus

  9. Title: Comprehensive Survey of Bullhead Lake (MWBC 68300), Manitowoc County

    E-print Network

    Survey Biologists; Steve Surendonk; Steve Hogler

    1999-01-01

    Survey Purpose: Determine the status of the fish community of Bullhead Lake in Manitowoc County by the use of a comprehensive fisheries survey and contact creel survey. Background on Bullhead Lake: Bullhead Lake is a seepage lake located in western Manitowoc County. The lake has a surface area of 67 acres, a maximum depth of 40 feet and a shoreline development factor of 1.07. The lake has one basin with an adjoining cattail wetland. The lake bottom consists of muck, sand and gravel and the water is considered hard. Bullhead Lake is surrounded by agricultural land with an increasing number of year round residences being built. A public access is present on the western side of the lake. A 1955 survey found the lake to be in poor condition dominated by “extremely thin ” black crappie and common carp. Further the survey findings found that the lake was lacking predators and was out of balance. The fish population was chemically eradicated with a fish suffocant in 1957 and restocked with

  10. BLACK BULLHEAD: AN INDICATOR OF THE PRESENCE OF CHEMICAL CARCINOGENS

    EPA Science Inventory

    The usefulness of exposing caged fish to polluted water to detect chemical carcinogens was demonstrated by the development of neoplasms on black bullheads. Chemical analysis in this case failed to indicate that that mutagenic or carcinogenic chemicals were present, perhaps becaus...

  11. Metabolism of chrysene by brown bullhead liver microsomes.

    PubMed

    Pangrekar, Jyotsna; Kole, Panna L; Honey, Sangeet A; Kumar, Subodh; Sikka, Harish C

    2003-01-01

    We have investigated the regio- and stereoselective metabolism of chrysene, a four-ring symmetrical carcinogenic polycyclic aromatic hydrocarbon (PAH), by the liver microsomes of brown bullhead (Ameriurus nebulosus), a bottom-dwelling fish species. The liver microsomes from untreated and 3-methylcholanthrene (3-MC)-treated brown bullheads metabolized chrysene at the rate of 30.1 and 82.2 pmol/mg protein/min, respectively. Benzo-ring diols (1,2-diol and 3,4-diol) were the major chrysene metabolites formed by liver microsomes from control and 3-MC-treated fish. However, the control microsomes produced a considerably higher proportion of chrysene 1,2-diol (benzo-ring diol with a bay region double bond) plus 1-hydroxychrysene, than 3,4-diol plus 3-hydroxychrysene, indicating that these microsomes are selective in attacking the 1,2- position of the benzo-ring. On the other hand, 3-MC-induced microsomes did not show such a regioselectivity in the metabolism of chrysene. Control bullhead liver microsomes, compared to control rat liver microsomes, produced a considerably higher proportion of chrysene 1,2-diol, the putative proximate carcinogenic metabolite of chrysene. Like rat liver microsomes, bullhead liver microsomes produced only trace amounts of the K-region diol. Chrysene 1,2-diol and 3,4-diol formed by the liver microsomes from both control and 3-MC-treated bullheads consisted predominantly of their R,R-enantiomers. Chrysene is metabolized by bullhead liver microsomal enzymes to its benzo-ring diols with a relatively lower degree of stereoselectivity compared to benzo[a]pyrene (a five-ring PAH), but with a higher degree of stereoselectivity compared to phenanthrene (a three-ring PAH). The data of this study, together with those from our previous studies with phenanthrene, benzo[a]pyrene and dibenzo[a,l]pyrene (a six-ring PAH), indicate that the regioselectivity in the metabolism of PAHs by brown bullhead and rainbow trout liver microsomes does not vary greatly with the size and shape of the molecule, whereas the degree of stereoselectivity in the metabolism of PAHs to benzo-ring dihydrodiols does. PMID:12520076

  12. Biotic and abiotic correlates with black bullhead population characteristics in Nebraska sandhill lakes

    USGS Publications Warehouse

    Phelps, Q.E.; Ward, M.J.; Paukert, C.P.; Chipps, S.R.; Willis, D.W.

    2005-01-01

    We explored relationships among black bullhead (Ameiurus melas) population characteristics and physicochemical attributes in shallow lakes and quantified relationships between population characteristics of black bullhead and sport fishes. Lake characteristics and fisheries survey data were collected from the Sandhills region of northcentral Nebraska from May through June, 1998 and 1999. Relative abundance of black bullheads was inversely related to proportional stock density (r=-0.672, df=15, P=0.004); however, neither relative weight nor growth was significantly (P ??? 0.20) related to black bullhead relative abundance. Population characteristics of common panfish species such as bluegill (Lepomis macrochirus), green sunfish (L. cyanellus), pumpkinseed (L. gibbosus), and yellow perch (Perca flavescens) were not correlated with black bullhead relative abundance or size structure. Rather, proportional stock density (r=0.655, df=10, P=0.029) and growth (r=0.59, df=11, P=0.04) of black bullhead were positively related to relative abundance of largemouth bass (Micropterus salmoides). Similarly, black bullhead relative abundance was inversely related to largemouth bass size structure (r=-0.51, df=14, P= 0.05). Black bullhead mean length at age 3 was positively related to total phosphorous concentration (r=0.65, df=16, P=0.004), and bullhead relative abundance was positively related to shoreline development index (r=0.46, df=22, P=0.03). Population characteristics of black bullhead appeared to have little influence on panfish communities. Rather, black bullhead abundance, predator density, and lake productivity exhibited stronger relationships with black bullhead population characteristics.

  13. Comparison of Concurrent Trap-Net and GillNet Samples for Black Bullheads

    Microsoft Academic Search

    Patrick A. Hanchin; David W. Willis; Todd R. St. Sauver

    2002-01-01

    We compared concurrent trap-net (i.e., modified fyke net) and gill-net catches of black bullhead (Ameiurus melas) from 28 South Dakota water bodies sampled in 2000 or 2001. The length-frequency distribution of sampled black bullheads was significantly different (P = 0.0001) between gears, primarily because the trap nets commonly collected bullheads less than 150 mm total length, while such fish were

  14. Population Characteristics of Black Bullhead (Ameiurus melas) in Iowa Natural Lakes

    Microsoft Academic Search

    Matthew D. Mork; Scott M. Bisping; Jesse R. Fischer; Michael C. Quist

    2009-01-01

    Black bullhead (Ameiurus mefas) populations in three natural lakes in northwestern Iowa were sampled to describe abundance, size structure, condition, mortality, recruitment variability, and growth in relation to a range of physical and limnological conditions. Six-hundred-and-fifty-three black bullhead were sampled with modified fyke nets during summer 2008 from Silver Lake, Lake Minnewashta, and West Okoboji Lake. Catch-per-unit-effort of black bullhead

  15. Regulation of the black bullhead hepatic beta-adrenoceptors.

    PubMed

    Dugan, Stephen G; Chen, Xi; Nickerson, James G; Montpetit, Colin J; Moon, Thomas W

    2008-02-01

    Black bullhead catfish (Ameiurus melas) were exposed to air for 1 h to examine the effect of an acute stress on the distribution and function of the hepatic beta-adrenoceptors (beta-ARs). Air exposure significantly reduced both adrenaline (ADR)- and noradrenaline (NADR)-stimulated glucose production in isolated hepatocytes with no effect on either receptor affinity (K(d)) or number of binding sites (B(max)). A 24 h exposure of isolated hepatocytes to the beta-agonist isoproterenol also had no significant impact on either binding parameter. Competition studies using selective agonists and antagonists suggest that the hepatic beta-AR in this species is pharmacologically beta(2)-like. However in addition to the beta(2)-AR, molecular evidence provides support for the existence of hepatic beta-ARs that phylogenetically group with the beta(3)-ARs and the beta(1)-ARs. Despite the presence of several potential phosphorylation sites in the third intracellular loop and cytoplasmic tail of the bullhead beta(2)-AR, no significant changes were observed in the binding parameters. While physiological data supports the presence of only a single subtype, molecular data supports the existence of multiple beta-AR subtypes in this species. The mechanisms thought to regulate mammalian beta-ARs exist in the bullhead ARs reported here but these mechanisms are not as effective in this fish system as in mammals. PMID:17964837

  16. A potential biomarker of androgen exposure in European bullhead (Cottus sp.) kidney

    E-print Network

    Paris-Sud XI, Université de

    A potential biomarker of androgen exposure in European bullhead (Cottus sp.) kidney Mélanie-structure of the kidney was characterized to identify normal structure of this organ, and histological changes previously described in the kidney of breeding male bullheads were quantified using the Kidney Epithelium Height (KEH

  17. Modulation of immune parameters by chemical environmental pressures in wild populations of European bullhead,

    E-print Network

    Paris-Sud XI, Université de

    bullhead, Cottus sp., from Vesle basin (Champagne, France). Anne Bado-Nilles1,2 , Sabrina Jolly2 , Alain immune status of European bullhead, Cottus sp., a sedentary fish, in the presence of various agricultural density gradient centrifugation and cell suspensions were adjusted to 10 6 cells.mL -1 . Leucocyte

  18. Physicochemical and Biological Influences on Black Bullhead Populations in Eastern South Dakota Glacial Lakes

    Microsoft Academic Search

    Michael L. Brown; David W. Willis; Brian G. Blackwell

    1999-01-01

    Lake and fish survey data (1991–1992) were compiled for 23 eastern South Dakota natural lakes to provide a basis for preliminary investigation of black bullhead (Ameiurus melas) populations. Survey data contained numerous physical and chemical variables describing lake environments and relative abundance and sue structure of the primary fish species present. Analyses indicated that abundance of black bullheads increased with

  19. Impact of black bullhead ( Ameiurus melas ) on turbidity in a diked wetland

    Microsoft Academic Search

    Eugene C. Braig; David L. Johnson

    2003-01-01

    Benthivorous fish in shallow, aquatic systems have been correlated with increased turbidity and declines in macrophyte production and wildlife use. Bullheads have been credited with increasing turbidity, but this has been seldom tested and has not been studied in a diked marsh. To assess the relationships of black bullhead (Ameiurus melas) and turbidity, we assembled mesocosmsin the Show Pool Management

  20. Pollution-induced behavioural effects in the brown bullhead (Ameiurus nebulosus)

    E-print Network

    Neff, Bryan D.

    Pollution-induced behavioural effects in the brown bullhead (Ameiurus nebulosus) Ross D. Breckels on biodiversity. Thus, it is important to understand the nature of pollution- induced change in aquatic ecosystems. We show that brown bullheads (Ameiurus nebulosus) may have evolved in response to chronic pollution

  1. Movements of brown bullheads in Presque Isle Bay, Lake Erie, Pennsylvania

    Microsoft Academic Search

    Michael J. Millard; David R. Smith; Eric Obert; James Grazio; Meredith L. Bartron; Colleen Wellington; Sara Grisè; Sean Rafferty; Robert Wellington; Shannon Julian

    2009-01-01

    Presque Isle Bay, Lake Erie, was listed as an Area of Concern (AOC) by the International Joint Commission in part because of the high incidence of external tumor in brown bullheads. Verifying the source of the possible contaminant exposure is critical to addressing the AOC designation. We used telemetry tracking (n=49 fish) to test the hypothesis that adult bullheads captured

  2. DNA DAMAGE AND EXTERNAL LESIONS IN BROWN BULLHEADS FROM CONTAMINATED HABITATS

    EPA Science Inventory

    The Comet assay was used to compare levels of DNA damage in brown bullheads (Ameiurus nebulosus) collected from three known contaminated locations, the Cuyahoga River, Ashtabula River, and Ashumet Pond (Cape Cod), with brown bullheads collected from three paired reference sites, ...

  3. A potential biomarker of androgen exposure in European bullhead (Cottus sp.) kidney.

    PubMed

    Villeret, Mélanie; Jolly, Sabrina; Wiest, Laure; Vulliet, Emmanuelle; Bado-Nilles, Anne; Porcher, Jean-Marc; Betoulle, Stéphane; Minier, Christophe; Sanchez, Wilfried

    2013-06-01

    The aim of this study was to identify a signal that could be used as an androgen exposure indicator in the European bullhead (Cottus sp.). For this purpose, the ultra-structure of the kidney was characterized to identify normal structure of this organ, and histological changes previously described in the kidney of breeding male bullheads were quantified using the kidney epithelium height (KEH) assay previously developed and validated for the stickleback. In the next step, the effect of trenbolone acetate (TbA), a model androgen, was assessed to identify potential androgenic regulation of bullhead kidney hypertrophy. Measurement of KEH performed on adult non-breeding male and female bullheads exposed for 14 and 21 days to 0, 1.26 and 6.50 ?g/L showed that kidney hypertrophy is induced in a dose-dependent manner, confirming the hypothesis that the European bullhead possesses a potential biomarker of androgen exposure. Combined with the wide distribution of the European bullhead in European countries and the potential of this fish species for environmental toxicology studies in field and laboratory conditions, the hypothesis of a potential biomarker of androgen exposure offers interesting perspectives for the use of the bullhead as a relevant sentinel fish species in monitoring studies. Inducibility was observed with high exposure concentrations of TbA. Further studies are needed to identify molecular signals that could be more sensitive than KEH. PMID:23010938

  4. SERUM CHEMISTRY AND HISTOPATHOLOGICAL EVALUATIONS OF BROWN BULLHEADS (AMEIURUS NEBULOSUS) FROM THE BUFFALO AND NIAGARA RIVERS

    EPA Science Inventory

    Cholangiomas and cholangiocarcinomas were observed in brown bullheads (Ameiurus nebulosus) collected from the Buffalo and Niagara Rivers (NY) and Old Woman Creek (OH). ignificant increases in serum BUN, uric acid, triglycerides inorganic phosphate, ALT, LDL, calcium and iron and ...

  5. First record of the black bullhead Ameiurus melas (Teleostei: Ictaluridae) in Poland.

    PubMed

    Nowak, M; Kosco, J; Popek, W; Epler, P

    2010-04-01

    The North American catfish, the black bullhead Ameiurus melas, is recorded for the first time in Poland. The origin of these fish is not clear, but their presence may be associated with unregulated introductions by anglers. PMID:20537032

  6. Morphometry of non-native black bullhead Ameiurus melas from Slovakia

    Microsoft Academic Search

    Andrea Novomeská; Vladimír Ková?; Stanislav Katina

    2010-01-01

    The study on the external morphology of the non-native black bullhead (Ameiurus melas) was carried out on a population from Slovakia, based on triple regression and geometrical analysis. The breakpoints distribution\\u000a in distance-based morphometric characters indicated that black bullhead reached its definitive phenotype early in ontogeny.\\u000a Ontogenetic changes in external morphology occurred continuously throughout the whole size-range of the sample

  7. Endogenous antioxidant systems of two teleost fish, the rainbow trout and the black bullhead, and the effect of age

    Microsoft Academic Search

    Diana M. E. Otto; Thomas W. Moon

    1996-01-01

    Antioxidant enzyme activities and glutathione status were determined in different tissues of two teleost species, the rainbow trout (Oncorhynchus mykiss) and the black bullhead (Ameiurus melas) to establish whether age-related changes exist between mature and immature individuals. Glutathione reductase and superoxide dismutase activities were significantly lower in hepatic and extrahepatic tissues of 3+ year than 1+ year trout and bullheads.

  8. The inf luence of the invasive black bullhead Ameiurus melas on the predatory efficiency of pike Esox lucius L

    Microsoft Academic Search

    K. KREUTZENBERGER; F. L EPRIEUR; S. BROSSE

    2008-01-01

    The influence of the invasive black bullhead Ameiurus melas on the predatory efficiency of the pike Esox lucius was investigated using an additive experimental design. Pike predatory success on 0þ years roach Rutilus rutilus was significantly reduced in the presence of black bullhead. Among the different hypotheses that may explain such a pattern, the hypothesis of direct competition between pike

  9. PATHOLOGICAL AND SERUM CHEMISTRY PROFILES OF BROWN BULLHEADS (AMERIURUS NEBULOSUS) FROM THE BLACK RIVER AND OLD WOMAN CREEK, OHIO

    EPA Science Inventory

    This study compares serum chemistry values for brown bullheads (Amciurus nebulosus) from the industrially contaminated Black River, Ohio, with the rural and relatively uncontaminated Old Woman Creek, Ohio. ifty-two percent (24 of 46) brown bullheads over 3-years-old had liver neo...

  10. In vitro kinetics of hepatic glutathione s-transferase conjugation in largemouth bass and brown bullheads

    SciTech Connect

    Gallagher, E.P.; Sheehy, K.M.; Lame, M.W.; Segall, H.J.

    2000-02-01

    The kinetics of glutathione 5-transferase (GST) catalysis were investigated in largemouth bass (Micropterus salmoides) and brown bullheads (Amerius nebulosus), two freshwater fish species found in a variety of polluted waterways in the eastern US. The initial rates of hepatic GST activity toward four GST substrates, including 1-chloro-2,4-dinitrobenzene, ethacrynic acid, {Delta}5-androstene-17-dione, and nitrobutyl chloride, were significantly higher in brown bullheads than in largemouth bass. Hepatic GST activity toward 1,2-dichloro-4-nitrobenzene, a {mu}-class GST substrate in rodents, was not detectable in either species. Liver cytosolic GSTs were more efficient in bullheads than in bass at catalyzing 1-chloro-2,4-dinitrobenzene-reduced glutathione (CDNB-GSH) conjugation over a broad range of electrophile (CDNB) concentrations, including those representative of environmental exposure. In contrast, largemouth bass maintained higher ambient concentrations of GSH, the nucleophilic cofactor for GST-mediated conjugation, than brown bullheads. Biphasic kinetics for GST-CDNB conjugation under conditions of variable GSH concentration were apparent in Eadie-Hofstee plots of the kinetic data, suggesting the presence of at least two hepatic GST isozymes with markedly different K{sub m} values for GSH in both species. The GST-CDNB reaction rate data obtained under conditions of variable GSH were well fitted (R{sup 2} = 0.999) by the two-enzyme Michaelis-Menten equation. In addition, Western blotting experiments confirmed the presence of two different hepatic GST-like proteins in both largemouth bass and brown bullhead liver. Collectively, these findings indicate that largemouth bass and brown bullhead GSTs catalyze the conjugation of structurally diverse, class-specific GST substrates, and that brown bullheads exhibit higher initial rates of GST activity than largemouth bass. The relatively higher rates of in vitro liver GST activity at the low substrate concentrations relevant to environmental exposure is expected to protect brown bullheads from the toxic effects of sediment-associated electrophilic chemicals. The somewhat lower rates of GST activity in largemouth bass liver compared with brown bullhead liver, however, may be offset by maintenance of higher ambient hepatic GSH concentrations in largemouth bass.

  11. Biomarkers of exposure of brown bullheads to contaminants in the lower Great Lakes

    SciTech Connect

    Arcand, L.D.; Metcalfe, C.D. [Trent Univ., Peterborough, Ontario (Canada). Environmental and Resource Studies Program

    1995-12-31

    Brown bullheads (Ameiurus nebulosus) were collected from contaminated and relatively pristine sites distributed throughout Lake Erie and Lake Ontario. Hepatic neoplasms were detected in bullheads from the contaminated sites of Hamilton Harbour (L. Ontario), the Black River (L. Erie) and the Detroit River, but no tumors were observed in bullheads from the relatively pristine Bay of Quinte (L. Ontario) and Old Woman Creek (L. Erie). Analysis of various biochemical markers of exposure to contaminants indicated that bullheads from the contaminated sites had elevated hepatic EROD activity, high levels of fluorescent aromatic compounds (FACS) in bile, and alterations to hepatic retinoid levels. Bullheads captured in the Black River also had an increased incidence of micronucleated hepatocytes in comparison to fish from Old Woman Creek. Although the prevalence of hepatic neoplasms was highest in Detroit River fish, all biomarkers did not necessarily indicate that Detroit River fish were the most highly exposed to contaminants. These data indicate that a suite of several biomarkers should be used to monitor for in situ exposure of fish to contaminants.

  12. Decreased glutathione S-transferase expression and activity and altered sex steroids in Lake Apopka brown bullheads (Ameriurus nebulosus)

    USGS Publications Warehouse

    Gallagher, E.P.; Gross, T.S.; Sheehy, K.M.

    2001-01-01

    A number of freshwater lakes and reclaimed agricultural sites in Central Florida have been the receiving waters for agrochemical and municipal runoff. One of these sites, Lake Apopka, is also a eutrophic system that has been the focus of several case studies reporting altered reproductive activity linked to bioaccumulation of persistent organochlorine chemicals in aquatic species. The present study was initiated to determine if brown bullheads (Ameriurus nebulosus) from the north marsh of Lake Apopka (Lake Apopka Marsh) exhibit an altered capacity to detoxify environmental chemicals through hepatic glutathione S-transferase (GST)-mediated conjugation as compared with bullheads from a nearby reference site (Lake Woodruff). We also compared plasma sex hormone concentrations (testosterone, 17-?? estradiol, and 11 keto-testosterone) in bullheads from the two sites. Female bullheads from Lake Apopka had 40% lower initial rate GST conjugative activity toward 1-chloro-2,4-dinitrobenzene (CDNB), 50% lower activity towards p-nitrobutyl chloride (NBC), 33% lower activity toward ethacrynic acid (ECA), and 43% lower activity toward ??5-androstene-3,17-dione (??5-ADI), as compared with female bullheads from Lake Woodruff. Enzyme kinetic analyses demonstrated that female bullheads from Lake Apopka had lower GST-catalyzed CDNB clearance than did female Lake Woodruff bullheads. Western blotting studies of bullhead liver cytosolic proteins demonstrated that the reduced GST catalytic activities in female Lake Apopka bullheads were accompanied by lower expression of hepatic GST protein. No site differences were observed with respect to GST activities or GST protein expression in male bullheads. Female Lake Apopka bullheads also had elevated concentrations of plasma androgens (testosterone and 11-ketotestosterone) as compared with females from Lake Woodruff. In contrast, male Lake Apopka bullheads had elevated levels of plasma estrogen but similar levels of androgens as compared with male bullheads from Lake Woodruff. Collectively, our studies indicate the presence of reduced GST protein expression, reduced GST conjugative capacity and altered sex steroid homeostasis in female bullheads from a contaminated field site in Central Florida. The implications of these physiological alterations in terms of pollutant biotransformation and reproduction are discussed. ?? 2001 Elsevier Science B.V. All rights reserved.

  13. Prevalence of Tumors in Brown Bullhead from Three Lakes in Southeastern Massachusetts, 2002

    USGS Publications Warehouse

    Baumann, Paul C.; LeBlanc, Denis R.; Blazer, Vicki S.; Meier, John R.; Hurley, Stephen T.; Kiryu, Yasu

    2008-01-01

    The Massachusetts Military Reservation (MMR) has been a military base on western Cape Cod since the early 1900s. Contaminated surface water and ground water from the MMR have discharged into several kettle lakes on or near the base. To discover whether the prevalences of tumors and other lesions in brown bullhead (Ameiurus nebulosus) in these lakes, particularly Ashumet Pond, were elevated above normal, the U.S. Geological Survey (USGS), assisted by the U.S. Environmental Protection Agency (USEPA) and the Massachusetts Division of Fisheries and Wildlife (MADFW), conducted a study in 2002 of brown bullhead in Ashumet Pond and in two reference lakes, Santuit Pond (on Cape Cod) and Great Herring Pond (on the mainland of Massachusetts). Brown bullhead from Great Herring Pond had few external raised lesions (2.8 percent), a low prevalence of liver neoplasms (5 percent), and little genetic damage to their red blood cell nuclei. Brown bullhead from Ashumet Pond had a high prevalence of raised lesions (62.1 percent), which included histopathologically verified papillomas and squamous carcinoma; an elevated incidence of liver neoplasms (16.7 percent); and an elevated level of genetic damage to their red blood cell nuclei. Because red blood cells in fish have a lifespan of about 100 days, these results indicate an ongoing exposure to genotoxins in Ashumet Pond. Brown bullhead from Santuit Pond also had elevated prevalences of raised lesions (48.3 percent) and liver neoplasms (15 percent), although the prevalences of large and multiple lesions were significantly lower than those in fish from Ashumet Pond. These differences may indicate differing causes of pathology in the two lakes. The high prevalence of melanistic lesions on brown bullhead from Ashumet Pond, combined with the tumor pathology and genetic damage, implicates chemical carcinogens as one of the causal factors in that lake.

  14. Diagnostic criteria for proliferative hepatic lesions in brown bullhead Ameiurus nebulosus

    USGS Publications Warehouse

    Blazer, V.S.; Fournie, J.W.; Wolf, J.C.; Wolfe, M.J.

    2006-01-01

    Brown bullhead Ameiurus nebulosus is used as indicator species for contaminant effects at areas of concern (AOC) in the Great Lakes and other areas. One of the beneficial use impairments at numerous AOC is 'fish tumors and other deformities'. An impairment occurs when the prevalence of fish tumors and other deformities exceeds those at unimpacted or control sites or when survey data confirm the presence of neoplastic or preneoplastic liver lesions in bullhead or white sucker Catostomus commersonii. Numerous surveys have been conducted over the years assessing neoplasia in these fishes, both liver and skin tumors. However, a major problem in comparing the results has been a lack of consistent criteria for evaluating histological changes in bullhead livers. As individual AOC develop and implement remedial action plans, realistic and attainable delisting targets need to be specified. For this to occur and be consistent from site to site there must be standardization of the criteria being used to evaluate specific impairments. In this report, specific diagnostic criteria are provided for both non-neoplastic and neoplastic proliferative hepatocellular and biliary lesions. These criteria should assist fish pathologists in describing and categorizing proliferative liver lesions from brown bullhead. ?? Inter-Research 2006.

  15. Ulcerative Mycosis Caused by Aphanomyces invadans in Channel Catfish, Black Bullhead, and Bluegill from Southeastern Louisiana

    Microsoft Academic Search

    John P. Hawke; Amy M. Grooters; Alvin C. Camus

    2003-01-01

    Eight cases of chronic ulcerative mycosis affecting populations of channel catfish Ictalurus punctatus, black bullhead Ameiurus melas, and bluegill Lepomis macrochirus cultured in recreational fishing ponds were submitted to the Louisiana Aquatic Diagnostic Laboratory between April 2000 and January 2002. Diseased clinical specimens presented with multiple foci of skin ulceration, typically overlying more extensive areas of granulomatous myositis that extended

  16. Tumor Rates and Population Estimates of Brown Bullhead ( Ameiurus nebulosus) in Presque Isle Bay, Lake Erie

    Microsoft Academic Search

    Mark Pyron; Eric C. Obert; Robert Wellington

    2001-01-01

    Tumor rate and population estimates for brown bullhead (Ameiurus nebulosus) in Presque Isle Bay, Lake Erie were monitored between 1992 and 1999. Fish were collected by electrofishing and trapnet. Skin tumor (grossly observable external lesions) rate decreased from 61% in 1992 to 19% in 1999. Liver tumor rate decreased from 22% in 1992 to 0% in 1999. Length-frequency histograms, collection

  17. SYNCHRONOUS FLUOROMETRIC MEASUREMENT OF METABOLITES OF POLYCYCLIC AROMATIC HYDROCARBONS IN THE BILE OF BROWN BULLHEAD

    EPA Science Inventory

    A synchronous fluorescent spectroscopy (SFS) method was developed to measure pyrene-type metabolites in the bile of brown bullhead (Ameiurus nebulosus) and to estimate the exposure of fish to PAHs in four Lake Erie tributaries collected in the spring and fall of 1990 and 1991. Fo...

  18. Tumor prevalence and biomarkers of genotoxicity in brown bullhead (Ameiurus nebulosus) in Chesapeake Bay tributaries

    USGS Publications Warehouse

    Pinkney, Alfred E.; Harshbarger, John C.; Karouna-Renier, Natalie K.; Jenko, Kathryn; Balk, Lennart; Skarphéðinsdóttir, Halldora; Liewenborg, Birgitta; Rutter, Michael A.

    2011-01-01

    We surveyed four Chesapeake Bay tributaries for skin and liver tumors in brown bullhead (Ameiurus nebulosus). We focused on the South River, where the highest skin tumor prevalence (53%) in the Bay watershed had been reported. The objectives were to 1) compare tumor prevalence with nearby rivers (Severn and Rhode) and a more remote river (Choptank); 2) investigate associations between tumor prevalence and polynuclear aromatic hydrocarbons (PAHs) and alkylating agents; and 3) statistically analyze Chesapeake Bay bullhead tumor data from 1992 through 2008. All four South River collections exhibited high skin tumor prevalence (19% to 58%), whereas skin tumor prevalence was 2%, 10%, and 52% in the three Severn collections; 0% and 2% in the Choptank collections; and 5.6% in the Rhode collection. Liver tumor prevalence was 0% to 6% in all but one South River collection (20%) and 0% to 6% in the three other rivers. In a subset of samples, PAH-like biliary metabolites and 32P-DNA adducts were used as biomarkers of exposure and response to polycyclic aromatic compounds (PACs). Adducts from alkylating agents were detected as O6-methyl-2'-deoxyguanosine (O6Me-dG) and O6-ethyl-2'-deoxyguanosine (O6Et-dG) modified DNA. Bullheads from the contaminated Anacostia River were used as a positive control for DNA adducts. 32P-DNA adduct concentrations were significantly higher in Anacostia bullhead livers compared with the other rivers. We identified alkyl DNA adducts in bullhead livers from the South and Anacostia, but not the Choptank. Neither the PAH-like bile metabolite data, sediment PAH data, nor the DNA adduct data suggest an association between liver or skin tumor prevalence and exposure to PACs or alkylating agents in the South, Choptank, Severn, or Rhode rivers. Logistic regression analysis of the Chesapeake Bay database revealed that sex and length were significant covariates for liver tumors and length was a significant covariate for skin tumors.

  19. Tumor prevalence and biomarkers of genotoxicity in brown bullhead (Ameiurus nebulosus) in Chesapeake Bay tributaries

    USGS Publications Warehouse

    Pinkney, A.E.; Harshbarger, J.C.; Karouna-Renier, N. K.; Jenko, K.; Balk, L.; Skarpheinsdottir, H.; Liewenborg, B.; Rutter, M.A.

    2011-01-01

    We surveyed four Chesapeake Bay tributaries for skin and liver tumors in brown bullhead (Ameiurus nebulosus). We focused on the South River, where the highest skin tumor prevalence (53%) in the Bay watershed had been reported. The objectives were to 1) compare tumor prevalence with nearby rivers (Severn and Rhode) and a more remote river (Choptank); 2) investigate associations between tumor prevalence and polynuclear aromatic hydrocarbons (PAHs) and alkylating agents; and 3) statistically analyze Chesapeake Bay bullhead tumor data from 1992 through 2008. All four South River collections exhibited high skin tumor prevalence (19% to 58%), whereas skin tumor prevalence was 2%, 10%, and 52% in the three Severn collections; 0% and 2% in the Choptank collections; and 5.6% in the Rhode collection. Liver tumor prevalence was 0% to 6% in all but one South River collection (20%) and 0% to 6% in the three other rivers. In a subset of samples, PAH-like biliary metabolites and 32P-DNA adducts were used as biomarkers of exposure and response to polycyclic aromatic compounds (PACs). Adducts from alkylating agents were detected as O6-methyl-2'-deoxyguanosine (O6Me-dG) and O6-ethyl-2'-deoxyguanosine (O6Et-dG) modified DNA. Bullheads from the contaminated Anacostia River were used as a positive control for DNA adducts. 32P-DNA adduct concentrations were significantly higher in Anacostia bullhead livers compared with the other rivers. We identified alkyl DNA adducts in bullhead livers from the South and Anacostia, but not the Choptank. Neither the PAH-like bile metabolite data, sediment PAH data, nor the DNA adduct data suggest an association between liver or skin tumor prevalence and exposure to PACs or alkylating agents in the South, Choptank, Severn, or Rhode rivers. Logistic regression analysis of the Chesapeake Bay database revealed that sex and length were significant covariates for liver tumors and length was a significant covariate for skin tumors. ?? 2011.

  20. SERUM CHEMISTRY AND HISTOPATHOLOGICAL EVALUATIONS OF BROWN BULLHEADS (AMEIRUS NEBULOSUS) FROM THE BUFFALO AND NIAGARA RIVERS, NEW YORK

    EPA Science Inventory

    Cholangiomas and cholangiocarcinomas were observed in brown bullheads (Ameiurus nebulosus) collected from the Buffalo and Niagara Rivers (NY) and Old Woman Creek (OH), USA. ignificant increases in serum blood urea nitrogen, uric acid, triglycerides, inorganic phosphate, ALT, LDL,...

  1. 78 FR 13811 - Special Local Regulation; Annual Marine Events on the Colorado River, Between Davis Dam (Bullhead...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-01

    ...Regulation; Annual Marine Events on the Colorado River, Between Davis Dam (Bullhead...Local Regulation located upon the Colorado River from 8 a.m. through 5 p.m...other Federal, State, or local law enforcement agencies in...

  2. Evaluation of a Mechanical Population Reduction of Black Crappie and Black Bullheads in a Small Wisconsin Lake

    Microsoft Academic Search

    David A. Hanson; Brian J. Belonger; Dean L. Schoenike

    1983-01-01

    The large populations of black crappies (Pomoxis nigromaculatus) and black bullheads (Ictalurus melas) in 20.2-hectare English Lake, Manitowoc County, Wisconsin, had a size distribution undesirable for angling. An attempt was made to reduce the abundance of these species and improve growth rates by mechanical removal (trapping) of 2,822 black crappies per hectare and 277 black bullheads per hectare in the

  3. Induction of micronuclei and nuclear abnormalities in the erythrocytes of mudminnows ( Umbra limi ) and brown bullheads ( Ictalurus nebulosus )

    Microsoft Academic Search

    C. D. Metcalfe

    1988-01-01

    The authors are interested in determining whether the MN technique can be developed as an in situ assay for genotoxicity in fish species; and in particular, the brown bullhead (Ictalurus nebulosus). In this study, central mudminnows (Umbra limi) and brown bullheads were exposed to EMS and benzo(a)pyrene (BaP) by intraperitoneal injection. The various experiments were designed to: i) compare the

  4. DNA damage and external lesions in brown bullheads (Ameiurus nebulosus) from contaminated habitats

    USGS Publications Warehouse

    Yang, X.; Meier, J.; Chang, L.; Rowan, M.; Baumann, P.C.

    2006-01-01

    The Comet assay was used to compare levels of DNA damage in brown bullheads (Ameiurus nebulosus) collected from three known contaminated locations, the Cuyahoga River (OH, USA), Ashtabula River (OH, USA; both tributaries to Lake Erie, USA), and Ashumet Pond (Cape Cod, MA, USA), with brown bullheads collected from three paired reference sites, Old Woman Creek (OH, USA), Conneaut River (OH, USA; both tributaries to Lake Erie), and Great Herring Pond (mainland MA, USA), respectively. Blood was sampled from each fish, and the Comet assay was conducted on erythrocytes. The assay results demonstrate that fish from the three contaminated sites each suffered higher DNA damage compared with fish from their respective reference sites. The results also show that the genetic damage was associated with the occurrence of external lesions and deformities in fish. The Comet assay is sufficiently sensitive to detect exposure of natural fish populations to environmental levels of genotoxic contaminants. ?? 2006 SETAC.

  5. Pollution-induced behavioural effects in the brown bullhead ( Ameiurus nebulosus )

    Microsoft Academic Search

    Ross D. Breckels; Bryan D. Neff

    2010-01-01

    Aquatic ecosystems are major sinks for pollutants which can have adverse effects on biodiversity. Thus, it is important to\\u000a understand the nature of pollution-induced change in aquatic ecosystems. We show that brown bullheads (Ameiurus nebulosus) may have evolved in response to chronic pollution exposure. We collected adults from the Detroit River (polluted site) and\\u000a Belle River (control site). Both adults

  6. Biomarkers of Oxidative Stress and Genotoxicity in Livers of Field-Collected Brown Bullhead, Ameiurus nebulosus

    Microsoft Academic Search

    V. A. McFarland; L. S. Inouye; C. H. Lutz; A. S. Jarvis; J. U. Clarke; D. D. McCant

    1999-01-01

    .   The objective of this investigation was to determine whether differences in a suite of biomarker assays in brown bullhead\\u000a liver tissues could be detected and related to the pollution histories of two Ohio locations, one a reach of the Black River\\u000a that had historically been severely impacted by the effluents of a coking plant, the other at Old Woman

  7. Evidence that elevated water temperature affects the reproductive physiology of the European bullhead Cottus gobio

    Microsoft Academic Search

    Jennifer DortsGael; Gaël Grenouillet; Jessica Douxfils; Syaghalirwa N. M. Mandiki; Sylvain Milla; Frédéric Silvestre; Patrick Kestemont

    Climate change is predicted to increase the average water temperature and alter the ecology and physiology of several organisms\\u000a including fish species. To examine the effects of increased water temperature on freshwater fish reproduction, adult European\\u000a bullhead Cottus gobio of both genders were maintained under three temperature regimes (T1: 6–10, T2: 10–14 and T3: 14–18°C) and assessed for gonad\\u000a development

  8. Tumor prevalence and biomarkers in brown bullheads (Ameiurus nebulosus) from the tidal Potomac River watershed [poster

    USGS Publications Warehouse

    Pinkney, A.E.; Harshbarger, J.C.; May, E.B.; Melancon, M.J.

    2000-01-01

    Associations between contaminant exposure and liver and skin tumor prevalence were evaluated in brown bullheads (Ameiurus nebulosus) from the tidal Potomac River watershed. Thirty bullheads (>260 mm) were collected from (1) Quantico embayment, near a Superfund site which released organochlorine contaminants; (2) Neabsco Creek, a tributary with petroleum inputs from runoff and marinas; and (3) Anacostia River (spring and fall), an urban tributary designated as a Chesapeake Bay Region of Concern, contaminated with PCBs, PAHs, and organochlorine pesticides. Fish were collected from the Tuckahoe River, as a reference. Cytochrome P450 activity, bile PAH metabolites, and muscle organochlorine pesticide/PCB concentrations were measured in randomly-selected individuals and sediment contaminants were analyzed. We found statistically significant differences in liver tumor prevalences: Anacostia (spring)-50%, Anacostia (fall)-60%, Neabsco-17%, Quantico-7%, Tuckahoe-10%. Skin tumor prevalences were significantly different: Anacostia (spring)-37%, Anacostia (fall)-10%, Neabsco-3%, Quantico-3%, Tuckahoe-0%. Tumor prevalence in Anacostia bullheads warrants concern and was similar to those at highly contaminated sites in the Great Lakes. There was evidence of higher PAH exposure in Anacostia fish but a cause-effect linkage cannot be established. Fish tumor surveys, with histopathological examination of internal and external organs, are recommended for monitoring the status of Regions of Concern.

  9. Effect of remedial dredging on bullhead tumor frequency in a recovering river

    SciTech Connect

    Baumann, P. [National Biological Service, Columbus, OH (United States)

    1995-12-31

    In 1980 and 1981 high tumor frequencies in brown bullhead from the Black River, Ohio were correlated with high concentrations of polynuclear aromatic hydrocarbons (PAH) in sediment. Surficial sediment levels of PAH dropped after a decline in the steel industry in 1982 followed by closure of the USX coke plant in 1983. By 1987 PAH concentrations had declined to less than one-hundredth of those found in 1980. During this same period liver cancer in age 3+ brown bullhead (Ameiurus nebulosus) underwent a significant decline to about one quarter of the 1982 frequency (38.5%) by 1987 (10%). Then in mid to late 1990, in a delayed reaction to a US EPA consent decree, PAH contaminated sediments were dredged from the river. Surveys in 1992 and 1993 revealed that the cancer frequency in age 3+ brown bullhead had increased to more than 45%. Preliminary 1994 data indicates a decline in grossly observable liver tumors (usually diagnosed as biliary cancers), along with declines in external tumors and eye pathology. The data fit the following hypothesis: Contaminated sediments become less bioavailable with time after a point source is removed, possibly due to deposition of cleaner sediment. Dredging temporarily restores bioavailability (and consequent effects). These data support the position that in some locations controlling contaminants in situ may be preferable to dredging on a cost-benefit basis.

  10. Movements of brown bullheads in Presque Isle Bay, Lake Erie, Pennsylvania

    USGS Publications Warehouse

    Millard, M.J.; Smith, D.R.; Obert, E.; Grazio, J.; Bartron, M.L.; Wellington, C.; Grise, S.; Rafferty, S.; Wellington, R.; Julian, S.

    2009-01-01

    Presque Isle Bay, Lake Erie, was listed as an Area of Concern (AOC) by the International Joint Commission in part because of the high incidence of external tumor in brown bullheads. Verifying the source of the possible contaminant exposure is critical to addressing the AOC designation. We used telemetry tracking (n = 49 fish) to test the hypothesis that adult bullheads captured within the bay during spawning season do not exit the bay during the post-spawning summer and fall months. We analyzed genetic variation at 15 microsatellite loci for 112 adult fish from 5 locations, 4 inside the bay and 1 outside, in order to test for possible differences. Data from fixed-station receivers suggested fish did not leave Presque Isle Bay during the study period. Predicted locations outside Presque Isle Bay were only 0.1% of all predicted locations and were below the 0.2% error rate based on known manual relocations. However, there was evidence for movement within Presque Isle Bay. Most movement was between Misery Bay or Lagoons and the open bay area. Whereas telemetry results showed tendency for adult site fidelity, genetic results showed no differences among locations, indicating that there is a single panmictic population. Our telemetry data suggest that brown bullheads are likely a useful indicator species for environmental conditions in Presque Isle Bay, since adults likely are retained in the system.

  11. Az-Tech Medicine.

    ERIC Educational Resources Information Center

    Nicholson, Rob

    2000-01-01

    Created in 1552 as a gift for Spain's king, the Badianus Manuscript is a repository of Aztec traditional medicinal knowledge and contains the earliest surviving illustrations of New World plants. At the College of Santa Cruz (Mexico City) for Aztec nobility, an Aztec healer who became the college physician compiled plant descriptions and medicinal…

  12. Tumor frequencies in walleye (Stizostedion vitreum) and brown bullhead (Ictalurus nebulosus) and sediment contaminants in tributaries of the Laurentian Great Lakes

    USGS Publications Warehouse

    Baumann, Paul C.; Mac, Michael J.; Smith, Stephen B.; Harshbarger, John C.

    1991-01-01

    To better characterize neoplasm epizootics in the Great Lakes basin and their association with families of contaminants, we samples five locations: the Fox and Menominee rivers, Lake Michigan; Munuscong Lake, St. Marys River; and the Black and Cuyahoga rivers, Lake Erie. Frequencies of external and liver tumors were determined for brown bullhead (Ictalurus nebulosus) from all locations except the Black River and for walleye (Stizostedion vitreum) from the Lake Michigan and St. Mary's River sites. Sediment samples were analyzed for metals, polychlorinated aromatics, and polynuclear aromatic hydrocarbons (PAH). Liver neoplasms occurred in brown bullhead from the Cuyahoga River and Munuscong Lake; brown bullhead captured from Munuscong Lake were older than those collected from the other locations. Brown bullhead from these same two rivers had elevated hepatosomatic indexes. No liver neoplasms were found in brown bullhead from the Fox and Menominee rivers, although polychlorinated aromatics were highest in both Fox River sediment and Fox and Menominee brown bullhead, and arsenic was highest in Menominee River sediment and fish. Liver neoplasms in brown bullhead from the Cuyahoga River fit the prevailing hypothesis that elevated PAH in sediment can induce cancer in wild fish. The cause of the liver neoplasms in Munuscong Lake brown bullhead is undetermined.

  13. Mortality and pathology in brown bullheads Amieurus nebulosus associated with a spontaneous Edwardsiella ictaluri outbreak under tank culture conditions

    USGS Publications Warehouse

    Iwanowicz, L.R.; Griffin, A.R.; Cartwright, D.D.; Blazer, V.S.

    2006-01-01

    Brown bullheads Amieurus nebulosus (family Ictaluridae) are commonly used as a sentinel of environmental contamination. These fish are not generally cultured under laboratory conditions and little is known about their disease susceptibility. Here we report an outbreak of disease due to Edwardsiella ictaluri in a laboratory population of tank-reared, wild-caught brown bullheads. The isolate was positively identified as E. ictaluri using standard bacteriological substrate utilization tests and a monoclonal antibody specific for this bacterium. This pathogen causes a significant disease in channel catfish Ictalurus punctatus and is associated with disease in other ictalurid and non-ictalurid fishes. It appears that E. ictaluri is also a significant pathogen in brown bullheads and produces clinical signs and lesions similar but not identical to those observed in channel catfish. Since commercial sources of bullheads for laboratory tank studies are not available, precautions should be taken to prevent potential E. ictaluri disease outbreaks from wild-caught bullheads intended for laboratory research. ?? Inter-Research 2006.

  14. Polybrominated diphenyl ethers and their methoxylated and hydroxylated analogs in Brown Bullhead (Ameiurus nebulosus) plasma from Lake Ontario.

    PubMed

    De la Torre, A; Pacepavicius, G; Martínez, M A; Darling, C; Muir, D; Sherry, J; McMaster, M; Alaee, M

    2013-02-01

    Polybrominated diphenyl ethers (PBDEs), methoxylated PBDEs (MeO-PBDEs) and hydroxylated PBDEs (OH-PBDEs) were detected and quantified in Brown Bullhead (Ameiurus nebulosus) from Lake Ontario. Samples were collected in 2006 from three different locations near the city of Toronto: Frenchman's Bay, Toronto Island, and Tommy Thompson Park. A total of 117 plasma samples were pooled into 19 samples, separating males and females by site of capture. Pooled samples were analyzed for 36 PBDEs, 20 MeO-PBDEs and 20 OH-PBDEs, but only six PBDEs, five MeO- and eight OH-compounds were confirmed against standards currently available. These peaks were quantified as "identified" peaks, while peaks matching ion ratios but not matching the retention time of the available standards were quantified as "unidentified" peaks. Both "identified" and "unidentified" concentrations were combined to obtain a total concentration. No significant variations were obtained for total PBDE concentrations, ranging from 3.33 to 9.02 ng g(-1)wet weight. However, OH- and MeO-PBDE totals ranged over 1 order of magnitude among the samples (not detected - 3.57 ng g(-1)wet weight for OH-PBDEs and not detected -0.10 ng/g wet weight for MeO-PBDE). The results of this study suggested that these compounds are ubiquitous in biota. Source estimation of MeO- and OH-PBDEs in freshwater fish were discussed. Considering that up to date no freshwater sources for MeO- or OH-PBDEs have been reported, concentrations found should be mainly related to bioaccumulation from anthropogenic sources, although other sources could not be dismissed. PMID:23121987

  15. Induction of micronuclei and nuclear abnormalities in the erythrocytes of mudminnows (Umbra limi) and brown bullheads (Ictalurus nebulosus)

    SciTech Connect

    Metcalfe, C.D.

    1988-04-01

    The authors are interested in determining whether the MN technique can be developed as an in situ assay for genotoxicity in fish species; and in particular, the brown bullhead (Ictalurus nebulosus). In this study, central mudminnows (Umbra limi) and brown bullheads were exposed to EMS and benzo(a)pyrene (BaP) by intraperitoneal injection. The various experiments were designed to: i) compare the sensitivity of the MN and SCE assays using the mudminnow model; ii) determine whether MN are induced in the erythrocytes of the brown bullhead by exposure to genotoxic chemicals (EMS and BaP); iii) determine whether erythrocytes harvested from the erythropoietic tissues of fish (pronephros) have a greater incidence of MN than peripheral erythrocytes; iv) examine the association between the induction of MN and the induction of nuclear abnormalities in erythrocytes after exposure of genotoxic agents.

  16. Endogenous antioxidant systems of two teleost fish, the rainbow trout and the black bullhead, and the effect of age.

    PubMed

    Otto, D M; Moon, T W

    1996-08-01

    Antioxidant enzyme activities and glutathione status were determined in different tissues of two teleost species, the rainbow trout (Oncorhynchus mykiss) and the black bullhead (Ameiurus melas) to establish whether age-related changes exist between mature and immature individuals. Glutathione reductase and superoxide dismutase activities were significantly lower in hepatic and extrahepatic tissues of 3+ year than 1+ year trout and bullheads. Activities of glutathione peroxidase, catalase and glutathione S-transferase did not exhibit a clear pattern, with decreases in liver and kidney, but increases in gill and muscle tissues. Glutathione concentrations were significantly higher in most tissues of 3+ year than in 1+ year trout, but remained unchanged or decreased in tissues of older bullheads. The results imply an age- or maturation-dependent effect on key antioxidant enzymes in various tissues of these 2 teleost species. Thus, age and maturation may impact upon the use of oxidative stress parameters as indicators of contaminant exposure in environmental studies. PMID:24194254

  17. Biochemical responses to sediment-associated contaminants in brown bullhead (Ameriurus nebulosus) from the Niagara River ecosystem

    Microsoft Academic Search

    NANCY A. Eufemia; TRACY K. Collier; JOHN E. Stein; DAVID E. Watson; RICHARD T. Di Giulio

    1997-01-01

    Brown bullhead (Ameriurus nebulosus) were collected from three sites in the Niagara River ecosystem in June and September of 1991, and sediment samples from these sites were obtained in July 1991. The sites were located in the Buffalo River, the Niagara River adjacent to the Love Canal dump site, and in Black Creek, a Canadian tributary of the Niagara River

  18. Colonization history of the Swiss Rhine basin by the bullhead (Cottus gobio): inference under a Bayesian spatially explicit framework

    Microsoft Academic Search

    SAMUEL NEUENSCHWANDER; CARLO R. LARGIADÈR; NICOLAS RA; MATHIAS CURRAT; PASCAL VONLANTHEN; LAURENT EXCOFFIER

    2008-01-01

    The present distribution of freshwater fish in the Alpine region has been strongly affected by colonization events occurring after the last glacial maximum (LGM), some 20 000 years ago. We use here a spatially explicit simulation framework to model and better understand their colonization dynamics in the Swiss Rhine basin. This approach is applied to the European bullhead (Cottus gobio),

  19. Aroclor 1248 exposure leads to immunomodulation, decreased disease resistance and endocrine disruption in the brown bullhead, Ameiurus nebulosus

    USGS Publications Warehouse

    Iwanowicz, L.R.; Blazer, V.S.; McCormick, S.D.; Van Veld, P.A.; Ottinger, C.A.

    2009-01-01

    The brown bullhead Ameiurus nebulosus is a species of the family Ictaluridae commonly used as a sentinel of environmental contamination. While these fish have been utilized for this purpose in areas contaminated with polychlorinated biphenyls (PCBs), few controlled, laboratory-based studies have been designed to document the effects of PCB mixtures in this species. Here, brown bullhead were exposed to the PCB mixture, Aroclor 1248, via intraperitoneal injection and the effects on immune function, plasma hormones and disease resistance were evaluated. Exposure to this mixture led to a decrease in bactericidal activity and circulating antibodies to Edwardsiella ictaluri present from a previous exposure to this pathogen. A subsequent E. ictaluri disease challenge led to significantly higher mortality in A1248 treated fish compared to vehicle-control fish. The mitogenic response to the T-cell mitogen, phytohemaglutinin-P, was increased compared to vehicle-control fish. The steroid hormone, cortisol, and the thyroid hormone, T3, were also significantly lower in A1248 exposed fish. In summary, we have validated a number of functional immune assays for application in brown bullhead immunotoxicity studies. Additionally, we have demonstrated that the PCB mixture (A1248) modulates both immune function and endocrine physiology in brown bullhead. Such data may compliment the interpretation of data yielded from applied field studies conducted in PCB contaminated aquatic ecosystems.

  20. Mitochondrial DNA diversity of brown bullhead from contaminated and relatively pristine sites in the Great Lakes

    SciTech Connect

    Murdoch, M.H.; Hebert, P.D.N. (Univ. of Guelph, Ontario (Canada). Dept. of Zoology)

    1994-08-01

    Brown bullhead were sampled from contaminated and relatively pristine sites to determine whether there was any association between genetic diversity and site contamination. Nine sites were sampled in the lower Great Lakes: five from Areas of Concern (identified by the International Joint Commission as having significant environmental degradation) and four from relatively clean areas of similar habitat type. Genetic variation was surveyed in the mitochondrial genome using restriction fragment length polymorphisms. Sixteen restriction enzymes were used to identify 42 distinct mitochondrial DNA haplotypes among 163 fish. Eight pairwise comparisons of populations at contaminated vs. clean sites showed that genetic diversity estimates were always lower in populations from contaminated sites. The most parsimonious explanation is that reduced diversity is a result of stochastic reductions in population size that have culled much of the genetic diversity from populations. Although contaminated sites support large populations of brown bullhead, historical environmental degradation at these sites may have reduced population size in the past, resulting in reduced present-day genetic diversity.

  1. Chlordane, DDT, PCB's, and other selected organic compounds in Asiatic clams and yellow bullhead in the Potomac River Basin, 1992

    USGS Publications Warehouse

    Zappia, Humbert

    1996-01-01

    Chlordane, DDT (dichlor-diphenyl-trichloroethane), and PCB's (polychlorinated biphenyls) were the most widespread organic contaminants detected during a 1992 survey of aquatic biological tissues in the Potomac River Basin. On the basis of existing U.S. Food and Drug Administration criteria, no new threats to human health were discovered, although chlordane concentrations may pose a threat to fish-eating wildlife. Chlordane exceeded the National Academy of Science and National Academy of Engineering recommended maximum concentration for the protection of fish-eating wildlife at two sites. The survey, conducted by the U.S. Geological Survey's National Water-Quality Assessment Program, sampled Asiatic clams (Corbicula fluminea) and yellow bullhead (Ameiurus natalis) at 16 sites to determine the occurrence and distribution of 29 hydrophobic organic compounds. Thirteen of these organic compounds were detected in the survey. Sites with the greatest number of compounds detected include the Potomac River near Alexandria, Va., with 6 compounds detected in Asiatic clam tissue, and Accotink Creek near Annandale, Va., with 11 compounds in yellow bullhead tissue. Chlordane was detected at six sites, with maximum concentrations of 31.1 ?g/kg (micrograms per kilograms) in Asiatic clam tissue and 127 ?g/kg in yellow bullhead whole-fish tissue. DDT was detected at five sites, with maximum concentrations of 12.9 ?g/kg in Asiatic clam tissue and 7.6 ?g/kg in yellow bullhead whole-fish tissue. PCB's were detected at nine sites, with maximum concentrations of 162 ?g/kg in Asiatic clam tissue and 146 mg/ kg in yellow bullhead whole-fish tissue.

  2. The Influence of Aluminum Content of AZ61 and AZ80 Magnesium Alloys on Hot Cracking

    Microsoft Academic Search

    C. J. Huang; C. M. Cheng; C. P. Chou

    2011-01-01

    This study aims to investigate how aluminum content in magnesium alloys AZ61 and AZ80 impacts the hot cracking susceptibility of magnesium alloys. Differences in aluminum content are known to influence the total crack length of hot cracking. Magnesium alloy AZ61's total crack length was the longest in one thermal cycle, while AZ80's total crack length increased as the number of

  3. Waste Toolkit A-Z Garden tools

    E-print Network

    Melham, Tom

    Waste Toolkit A-Z Garden tools Also see `Plant Swap' in the Waste Toolkit A-Z How can I reuse unwanted garden tools? You can take unwanted garden tools to the Orinoco Scrapstore in Headington, Oxford. Orinoco (see Contact at bottom of page) will accept unwanted garden tools as part of their community reuse

  4. Waste Toolkit A-Z Garden waste

    E-print Network

    Melham, Tom

    Waste Toolkit A-Z Garden waste Also see `Plant Swap' in the Waste Toolkit A-Z How can I recycle garden waste from my department? Typically, the University Parks Department collects and recycles the departments' green garden waste. The Parks Department takes the garden waste (grass, leaves and other plant

  5. Waste Toolkit A-Z Plastic Grundon

    E-print Network

    Melham, Tom

    Waste Toolkit A-Z Plastic ­ Grundon Also see `Swap Shop' and `Office Recycling ­ Grundon' in the Waste Toolkit A-Z How can I recycle plastic? There are lots of different types of plastic. Typically, waste contractors can only recycle PETE plastic and HDPE plastic. The University's preferred waste

  6. Waste Toolkit A-Z Glass Grundon

    E-print Network

    Melham, Tom

    Waste Toolkit A-Z Glass ­ Grundon How can I recycle glass? Departments can recycle small amounts of glass in the Grundon office recycling boxes (see Recycling in the Waste Toolkit A-Z). `Small amounts). When looking at the cost effectiveness of recycling versus waste to landfill, it's worth bearing

  7. Decline in liver neoplasms in wild brown bullhead catfish after coking plant closes and environmental PAHs plummet.

    PubMed

    Baumann, P C; Harshbarger, J C

    1995-02-01

    Polycyclic aromatic hydrocarbons (PAHs) in both sediment and brown bullhead catfish tissues from the Black River in Lorain County, Ohio, declined by 65% and 93%, respectively, between 1980 and 1982. Sediment PAHs declined an additional 99% by 1987, coincident with the closure of a coking facility in 1983. Contemporaneously, liver cancer in 3- to 4-year-old brown bullheads declined to about one-quarter the 1982 frequency (10% versus 39%) by 1987, while the percentage of livers without any proliferative lesions doubled (42% versus 20%). These changes were significant within age group. Our data affirm a cause-and-effect relationship between PAH exposure and liver cancer in wild fish. The data also support the efficacy of natural, unassisted remediation once the source of the pollution is eliminated. PMID:7737065

  8. Tumor prevalence and biomarkers of exposure in brown bullheads (Ameiurus nebulosus) from the tidal Potomac River, USA, watershed

    USGS Publications Warehouse

    Pinkney, A.E.; Harshbarger, J.C.; May, E.B.; Melancon, M.J.

    2001-01-01

    Associations between contaminant exposure and liver and skin tumor prevalence were evaluated in brown bullheads (Ameiurus nebulosus) from the tidal Potomac River, USA, watershed. Thirty bullheads (>age 3) were collected from Quantico embayment near a Superfund site that released organochlorine contaminants; Neabsco Creek, a tributary with petroleum inputs from runoff and marinas; and Anacostia River (spring and fall), an urban tributary designated as a Chesapeake Bay region of concern, that was contaminated with polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and organochlorine pesticides. Fish were collected from the Tuckahoe River, as a reference. Cytochrome P450 activity, bile PAH metabolites, and muscle organochlorine pesticide and PCB concentrations were measured in randomly selected individuals and sediment contaminants were analyzed. We found statistically significant differences in liver tumor prevalences: Anacostia (spring), 50%, Anacostia (fall), 60%, Neabsco, 17%, Quantico, 7%, and Tuckahoe, 10%. Skin tumor prevalences were significantly different: Anacostia (spring), 37%, Anacostia (fall), 10%, Neabsco, 3%, Quantico, 3%, and Tuckahoe, 0%. Tumor prevalences in Anacostia bullheads warrants concern and was similar to those as highly contaminated sites in the Great Lakes. Evidence was found of higher PAH exposure in Anacostia fish but a cause-effect linkage could not be established. Fish tumor surveys, with histopathologic examination of internal and external organs are recommended for monitoring the status of regions of concern.

  9. Indicators of exposure to polycyclic aromatic hydrocarbons (PAH) in brown bullhead from a remediated and an unremediated site

    SciTech Connect

    Jones, J.; Baumann, P. [Ohio State Univ., Columbus, OH (United States)

    1995-12-31

    Exposure to PAH in fish is indicated by the induction of cytochrome P4501A1 and its monooxygenase activities. Brown bullhead (Ameiurus nebulosus) from PAH-contaminated sites in the Black River, Ohio and from Hamilton Harbor, Ontario have a history of hepatic carcinoma. The Black River site has been remediated by dredging in 1990. Brown bullhead from this site was compared to those from unremediated Hamilton Harbor. A monooxygenase assay for ethoxyresorufin O-deethylase (EROD) was used to determine catalytic activity in liver. In addition, an enzyme-linked immunosorbent assay (ELISA) was used to quantify cytochrome P4501A1 induction in hepatic microsomes. Liver weight to body weight ratios were also examined. These parameters were compared among brown bullhead from remediated Black River, unremediated Hamilton Harbor, and uncontaminated control sites in Ohio. EROD levels were greater in fish from Hamilton Harbor than in fish from the Black River, though EROD levels from the Black River were still significantly greater than from control sites.

  10. 75 FR 14643 - Arizona Disaster #AZ-00011

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-26

    ...Declaration 12082 and 12083] Arizona Disaster AZ-00011 AGENCY...Assistance Only for the State of Arizona (FEMA- 1888-DR), dated...affected by the disaster: Primary Counties: Apache, Coconino, Gila, Greenlee, La Paz, Mohave,...

  11. 20. Streetscape, South Coronado Boulevard, looking southwest Righttoleft, AZ198(Margaret B. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. Streetscape, South Coronado Boulevard, looking southwest Right-to-left, AZ-198(Margaret B. Hill House), AZ-199 (Henry H. Hill House), AZ-200 (Henry H. Hill Rental House), AZ-201 (Otto Rosenthal House), AZ-202 (J. M. Stevens House), AZ-203 (L J. Dunagan House), AZ204 (C. W. Beck House), and AZ-205 (F. D. Connor House) face the street - Clifton Townsite, Confluence of Chase Creek & San Francisco River, Clifton, Greenlee County, AZ

  12. Petrovay: Napfizika A Nap az idoben A NAP AZ ID OBEN 1: T ORT ENETI BEVEZET ES

    E-print Network

    Petrovay, Kristóf

    Petrovay: Napfizika A Nap az idoben A NAP AZ ID OBEN 1: T ¨ORT ´ENETI BEVEZET ´ES Kr.e. 28: Az elso´esek Galilei, Fabricius, Scheiner, Harriot. #12;Petrovay: Napfizika A Nap az idoben 1611: J. Fabricius´eseit. Foltokat bolyg´okk´ent ´ertelmezi. #12;Petrovay: Napfizika A Nap az idoben 1613: G. Galilei: Istoria e

  13. Estimates of population genetic diversity in brown bullhead catfish by DNA fingerprinting

    SciTech Connect

    Roth, A.C.; Wessendarp, T.K.; Gordon, D.A.; Smith, M.K. [Environmental Protection Agency, Cincinnati, OH (United States); Lattier, D.L. [Oak Ridge Inst. for Science and Education, Cincinnati, OH (United States); Hertzberg, V.; Leonard, A. [Univ. of Cincinnati, OH (United States). Dept. of Environmental Health

    1994-12-31

    Estimates of population genetic diversity may be a sensitive indicator of environmental impact, since limiting the effective breeding population by any means will result in loss of some variant genotypes, as has been demonstrated by allozyme analysis. DNA fingerprinting techniques are also coming into use for population analyses, and the authors chose to apply fingerprinting analysis three populations of brown bullhead catfish collected in Northern Ohio. DNA was isolated from the red blood cells of individual fish. Purified DNAs were digested with EcoR1 restriction enzyme; the digests were then sized on a 1% agarose gel, transferred to nylon membranes and probed with a radiolabeled M13 probe using the Westneat hybridization protocol (Southern blotting). This method effects fragments containing VNTR (variable number of tandem repeat) sequences complementary to the M13, which are highly variable among individual catfish. Hybridized bands were visualized by a Molecular Dynamics phosphorimager and recorded and analyzed with its proprietary Imagequant image analysis program, Excel and SAS. A total of 10 variable bands were identified and their presence or absence scored in each individual. These data were analyzed to determine between and within-population similarity indices as well as population heterozygosity and genetic diversity measures.

  14. Susceptibility of black bullhead Ameiurus melas to a panel of ranavirus isolates.

    PubMed

    Gobbo, F; Cappellozza, E; Pastore, M R; Bovo, G

    2010-07-01

    Ranaviruses are considered a serious threat to lower vertebrates, including fish, amphibians and reptiles. However, epidemiological data on these agents are lacking, and further investigations are needed to understand the role of carriers and to update the list of susceptible hosts. We carried out various experimental infections under controlled conditions to contribute to the current knowledge on the susceptibility of black bullhead Ameiurus melas to European catfish virus (ECV) and other ranaviruses. A panel of 7 ranavirus isolates was used to challenge duplicate groups of A. melas juveniles maintained in aquaria supplied with running dechlorinated tap water. The experiments were performed at 15 and 25 degrees C. The results confirmed the high susceptibility of A. melas to ECV infection. Furthermore, a significant mortality associated with the typical signs of systemic viral infections was observed in groups challenged with Epizootic haematopoietic necrosis virus (EHNV) at 25 degrees C, and to a lesser extent, at 15 degrees C. No significant mortality was recorded in fish challenged with European sheatfish virus (ESV), Frog virus 3 (FV3), Rana esculenta virus-like (REV-like), Bohle iridovirus (BIV) or short-finned eel virus (SERV). PMID:20815324

  15. Morphological variability of black bullhead Ameiurus melas in four non-native European populations.

    PubMed

    Novomeská, A; Katina, S; Copp, G H; Pedicillo, G; Lorenzoni, M; Pompei, L; Cucherousset, J; Ková?, V

    2013-04-01

    External morphology in black bullhead Ameiurus melas, a fish species considered to have high invasive potential, was studied in its four non-native European populations (British, French, Italian and Slovak). The aim of this study was to examine this species' variability in external morphology, including ontogenetic context, and to evaluate its invasive potential. Specimens from all non-native populations reached smaller body size compared to individuals from native populations. Juvenile A. melas were found to have a relatively uniform body shape regardless of the population's origin, whereas adults developed different phenotypes depending upon location. Specimens from the U.K., Slovak and French populations appeared to be rather similar to each other, whereas the Italian population showed the most distant phenotype. This probably results from the different thermal regime in the Italian habitat. Ameiurus melas from non-native European populations examined in this study showed some potential to alter the body shape both within and between populations. The phenotypic plasticity of A. melas, however, was not found to be as significant as in other invasive fish species. The results suggest that morphological variability itself is not necessarily essential for invasive success. The invasiveness of A. melas is therefore probably favoured by variations in its life-history traits and reproduction variables, together with some behavioural traits (e.g. voracious feeding and parental care) rather than by phenotypic plasticity expressed in external morphology. PMID:23557294

  16. Biliary PAH metabolites and the hepatosomatic index of brown bullheads from Lake Erie tributaries

    USGS Publications Warehouse

    Yang, X.; Baumann, P.C.

    2006-01-01

    In studies designed to investigate the environmental exposure of fish in Lake Erie tributaries, a benthic fish, the brown bullhead (Ameiurus nebulosus), was collected from the industrially contaminated Detroit River, Ottawa River, Black River, Cuyahoga River-harbor and -upstream, Ashtabula River, Buffalo River, and Niagara River, and the non-industrialized Old Woman Creek during 1997-2000. Biliary benzo[a]pyrene (B[a]P)- and naphthalene (NAPH)-type metabolites and the hepatosomatic index (HSI) were measured in fish and compared between different sites. Fish from all of the contaminated sites except Niagara River had significantly higher concentrations of both types of polycyclic aromatic hydrocarbon (PAH) metabolites than fish from the Old Woman Creek. Concentrations of PAH metabolites in bile of fish were positively associated with concentrations of PAHs in sediments, supporting the use of bile metabolites as a measure of PAH exposure. Relatively low concentrations of PAHs detected in fish bile and sediments of the Niagara River, which had undergone extensive remediation, suggested a lowered PAH exposure for fish at this site. No apparent trend was observed in HSI between the industrialized and non-industrialized sites. This study demonstrates that biliary PAH metabolites are an effective indicator of exposure of fish to PAHs. However, because factors other than contamination could also affect the liver size of wild fish, HSI alone may be not a reliable biomarker for assessing contaminant stress. ?? 2005 Elsevier Ltd. All rights reserved.

  17. Bioaccumulation of cesium-137 in yellow bullhead catfish (Ameiurus natalis) inhabiting an abandoned nuclear reactor reservoir

    SciTech Connect

    McCreedy, C.D.; Glickman, L.T. [Purdue Univ., West Lafayette, IN (United States). Dept. of Veterinary Pathobiology; Jagoe, C.H.; Brisbin, I.L. Jr. [Univ. of Georgia, Aiken, SC (United States). Savannah River Ecology Lab.

    1997-02-01

    Bioaccumulation of {sup 137}Cs was investigated in yellow bullhead catfish (Ameiurus natalis) inhabiting an abandoned reactor reservoir, Pond B, Savannah River Site, Barnwell Co., South Carolina. The authors collected fish by trap-netting, and determined ages from pectoral spines. Muscle and other tissues were assayed for {sup 137}Cs by NaI-scintillation. Music {sup 137}Cs was unrelated to sex or mass of fish, but was related to age. Examination of least-squares means suggested that {sup 137}Cs in muscle increased up to about age 3, but did not increase with greater age. A modified Richards model showed equilibrium {sup 137}Cs concentration in muscle was acquired in approximately 2.4 years. Growth differed between sexes and the time to asymptotic body mass was longer than the time to attain equilibrium {sup 137}Cs concentration. Males attained an asymptotic mass of 577 g in approximately 6.3 years; females attained an asymptotic mass of 438 g in approximately 5.9 years. The cumulative {sup 137}Cs burden of the population was 4.9 {times} 10{sup 6} Bq, representing <0.001% of the {sup 137}Cs inventory of the reservoir. Concentration of {sup 137}Cs varied among tissues with gill and muscle the lowest and highest. Concentration of {sup 137}Cs in ovaries declined with increasing ovary mass. Until equilibrium is attained in these fish, {sup 137}Cs concentration is directly related to increasing age rather than size.

  18. Assessing the ecosystem service potential of Tucson AZ's urban forest

    NASA Astrophysics Data System (ADS)

    Pavao-Zuckerman, M.

    2011-12-01

    Urbanization is arguably one of the most dramatic forms of landscape change, and an important anthropogenic influence on the structure and function of ecosystems. Cities have obvious impacts on local ecologies and environments, such as shifts in species diversity and alteration of local microclimates. While scientists are now familiar with many of these localized impacts of urbanization, cities and suburban areas contribute to 10-15 % of surface land cover in the conterminous U.S., pointing to the potential, yet poorly understood, contribution of cities to regional, national, and global carbon (C) and energy budgets. As cities continue to expand urban ecologists place more emphasis on understanding the functions of urban ecosystems and the ecosystem services (e.g. habitat, air, and water quality) that cities provide. While studies demonstrate that the urban environment alters the structure and function of remnant patches of native ecosystems relative to their non-urban counterparts, the ability of restoration, planning, and design to improve the provision of ecosystem services is a new approach within ecology. One strategy involves green urban design, or using ecological principles for planning or reinvigorating certain ecological processes, in cities. Increasing the amount of vegetative cover can reduce this effect by reinforcing ecosystem services in cities, including shading of surfaces, promotion of cooling through evapotranspiration, and the sequestration of atmospheric CO2 in plant tissues and soils. However, the on-the-ground reality of such strategies is relatively unknown. A pilot study is being conducted in Tucson, AZ to investigate the impact of increasing the cover of trees in the urban landscape on local microclimates and the urban heat island. Trees (Velvet Mesquite, Chilean Mesquite, and Desert Willow) were planted in two neighborhoods in Tucson in 1990. We are collecting data during the summer 2011 monsoon (DBH, crown volume, and hemispherical canopy photos) to asses growth of the trees in the urban environment. These growth rates, and associated ecosystem services (C-sequestration, energy savings, pollution mitigation, etc.) are evaluated using US Forest Service models (Tree Carbon Calculator and i-tree software) to determine how the performance of trees in the Tucson urban environment perform vs. model predictions. We hypothesize that the models overestimate tree performance as Tucson differs in water availability relative to the cities the model was parameterized in (e.g. Glendale), both in terms of soil water holding capacities and also city "water culture." This preliminary study will provide a data collection framework for a citizen science urban forestry project which will provide data to improve environmental decision making related to the interaction of plants, water, and energy balance in this arid city.

  19. Assessment of the fish tumor beneficial use impairment in brown bullhead (Ameiurus nebulosus) at selected Great Lakes Areas of Concern

    USGS Publications Warehouse

    Blazer, Vicki S.; Mazik, Patricia M.; Iwanowicz, Luke R.; Braham, Ryan P.; Hahn, Cassidy M.; Walsh, Heather L.; Sperry, Adam J.

    2014-01-01

    A total of 878 adult Brown Bullhead were collected at 11 sites within the Lake Erie and Lake Ontario drainages from 2011 to 2013. The sites included seven Areas of Concern (AOC; 670 individuals), one delisted AOC (50 individuals) and three non-AOC sites (158 individuals) used as reference sites. These fish were used to assess the “fish tumor or other deformities” beneficial use impairment. Fish were anesthetized, weighed, measured and any external abnormalities documented and removed. Abnormal orocutaneous and barbel tissue, as well as five to eight pieces of liver, were preserved for histopathological analyses. Otoliths were removed and used for age analyses. Visible external abnormalities included reddened (raised or eroded), melanistic areas and raised growths on lips, body surface, fins and barbels. Microscopically, these raised growths included papilloma, squamous cell carcinoma, osteoma and osteosarcoma. Proliferative lesions of the liver included bile duct hyperplasia, foci of cellular alteration, bile duct (cholangioma, cholangiocarcinoma) and hepatocellular (adenoma, hepatic cell carcinoma) neoplasia. The two reference sites (Long Point Inner Bay, Conneaut Creek), at which 30 or more bullhead were collected had a skin tumor prevalence of 10% or less and liver tumor prevalence of 4% or less. Presque Isle Bay, recently delisted, had a similar liver tumor prevalence (4%) and slightly higher prevalence (12%) of skin tumors. The prevalence of skin neoplasms was 15% or less at sites in the Black River, Cuyahoga River and Maumee AOCs, while more than 20% of the bullheads from the Rochester Embayment, Niagara River, Detroit River and Ashtabula River AOCs had skin tumors. The prevalence of liver tumors was greater than 4% at all AOC sites except the Old Channel site at the Cuyahoga River AOC, Wolf Creek within the Maumee AOC and the upper and lower sites within the Niagara River AOC.

  20. Sediment PAHs and tumors in brown bullhead (Ameiurus nebulosus) at Featherstone National Wildlife Refuge, Virginia

    SciTech Connect

    Pinkney, A.E.; Sutherland, D.W.; Foley, R.E. [Fish and Wildlife Service, Annapolis, MD (United States). Chesapeake Bay Field Office; Harshbarger, J.C. [Smithsonian Institution, Washington, DC (United States)

    1995-12-31

    Featherstone National Wildlife Refuge is located in Virginia along the Potomac River, about 35.4 kilometers southwest of Washington, DC. The study objective was to verify past observations of gross lesions in several fish species, previously collected from Potomac River tributaries for contaminant analysis. Thirty brown bullhead (Ameiurus nebulosus) were collected from Neabsco Creek, which borders the refuge, 29 were collected from Farm Creek, which bisects the refuge, and 30 were collected from Marumsco Creek, 1.75 km upstream. Sediment concentrations of polynuclear aromatic hydrocarbons (PAHS) were measured because elevated levels have been associated with skin and liver tumors in this species. The average concentration of total carcinogenic PAHs in sediments was: Farm Creek (0.34 ppm) < Marumsco Creek (0.63 ppm) < Neabsco Creek (1.37 ppm). The prevalence of skin neoplasms (squamous carcinomas and papillomas) was 3.4% in Farm Creek, 16.6% in Marumsco Creek, and 33.3% in Neabsco Creek. This ranking and the rankings of the total number of fish with tumors, invasive tumors, or non-parasitic lesions all followed the trend in sediment carcinogenic PAHs (p < 0.003; Jongheere-Terpstra test). The prevalence of liver carcinomas (O% at Farm Creek, 3.3% at Marumsco Creek, and 10% at Neabsco Creek) was of borderline significance (p = 0.06). The highest sediment concentrations of total (25.5 ppm) and carcinogenic (2.70 ppm) PAHs were found in Neabsco Creek near a complex of three marinas. Further sampling should be conducted in Neabsco Creek to determine the sources and extent of PAH contamination. Laboratory exposures are recommended for establishing a cause-effect linkage between sediment and tumor incidence. Additional sediment chemistry is needed to determine if other carcinogens are present.

  1. Characterization of the histone H2A.Z-1 and H2A.Z-2 isoforms in vertebrates

    PubMed Central

    2009-01-01

    Background Within chromatin, the histone variant H2A.Z plays a role in many diverse nuclear processes including transcription, preventing the spread of heterochromatin and epigenetic transcriptional memory. The molecular mechanisms of how H2A.Z mediates its effects are not entirely understood. However, it is now known that H2A.Z has two protein isoforms in vertebrates, H2A.Z-1 and H2A.Z-2, which are encoded by separate genes and differ by 3 amino acid residues. Results We report that H2A.Z-1 and H2A.Z-2 are expressed across a wide range of human tissues, they are both acetylated at lysine residues within the N-terminal region and they exhibit similar, but nonidentical, distributions within chromatin. Our results suggest that H2A.Z-2 preferentially associates with H3 trimethylated at lysine 4 compared to H2A.Z-1. The phylogenetic analysis of the promoter regions of H2A.Z-1 and H2A.Z-2 indicate that they have evolved separately during vertebrate evolution. Conclusions Our biochemical, gene expression, and phylogenetic data suggest that the H2A.Z-1 and H2A.Z-2 variants function similarly yet they may have acquired a degree of functional independence. PMID:20003410

  2. Multi-biomarker approach in wild European bullhead, Cottus sp., exposed to1 agricultural and urban environmental pressures: practical recommendations for2

    E-print Network

    Paris-Sud XI, Université de

    1 Multi-biomarker approach in wild European bullhead, Cottus sp., exposed to1 agricultural Risques (INERIS), Unité8 d'Ecotoxicologie in vitro et in vivo, BP2, 60550 Verneuil-en-Halatte, France9 10-20Mar2014 Author manuscript, published in "Chemosphere 87, 7 (2012) 675-683" DOI : 10.1016/j

  3. Glucose Tolerance and Peripheral Glucose Utilization in Rainbow Trout ( Oncorhynchus mykiss), American Eel ( Anguilla rostrata), and Black Bullhead Catfish ( Ameiurus melas)

    Microsoft Academic Search

    N. J. Legate; A. Bonen; T. W. Moon

    2001-01-01

    This study tests the hypothesis that glucose tolerance in fish is related to nutrient preference and is correlated with white muscle glucose transporter and phosphorylation (hexokinase) activities. Glucose clearance was investigated in the carnivorous rainbow trout (Oncorhynchus mykiss) and American eel (Anguilla rostrata) (feeding and fasting) and the omnivorous black bullhead catfish (Ameiurus melas). Glucose tolerance was assessed by an

  4. Alloglossidium fonti sp. nov. (Digenea, Macroderoididae) from black bullheads in Minnesota with molecular differentiation from congeners and resurrection of Alloglossidium kenti

    Microsoft Academic Search

    Vasyl V. Tkach; Andrew M. Mills

    2011-01-01

    Alloglossidium fonti sp. nov. is described based on specimens from black bullheads (Ameiurus melas) collected from several localities in northwestern Minnesota. The new species is morphologically closest to A. corti and A. geminum. These two species were also found in the same region as A. fonti sp. nov. and sometimes in the same individual fish. Examination of numerous genetically marked

  5. 77 FR 19927 - Amendment of Class E Airspace; Willcox, AZ, and Revocation of Class E Airspace; Cochise, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-03

    ...Airport, Willcox, AZ. Controlled airspace is necessary to accommodate aircraft using Area Navigation (RNAV) Global Positioning System (GPS) standard instrument approach procedures at Cochise County Airport, Willcox, AZ. Decommissioning...

  6. Waste Toolkit A-Z Books Grundon

    E-print Network

    Melham, Tom

    Waste Toolkit A-Z Books ­ Grundon Can I recycle books? Yes. Departments and colleges can recycle unwanted books with Grundon Ltd. Or, you can donate unwanted books to the Oxfam Bookshop in St Giles, Oxford (see `Books Oxfam' in the Waste Toolkit). Oxfam reuses the books in various Oxfam bookshops. How

  7. Waste Toolkit A-Z Books Oxfam

    E-print Network

    Melham, Tom

    Waste Toolkit A-Z Books ­ Oxfam How can I recycle unwanted books? Oxfam and the University Sustainability Team have an arrangement for book reuse and recycling via the Oxfam Bookshop at 56 St Giles, Oxford, OX1 3LU. Departments and colleges can take their unwanted books to the bookshop during weekdays

  8. February 2014AZ1617 What is diabetes?

    E-print Network

    Sanderson, Mike

    February 2014AZ1617 What is diabetes? Diabetes is a disease that your blood glucose, also called get into the cells of your body for energy. People with diabetes don't make enough insulin or the body cells do not respond to insulin, causing glucose to build up in the blood. (See Figure: Diabetes

  9. Waste Toolkit A-Z Clothes & textiles

    E-print Network

    Oxford, University of

    Waste Toolkit A-Z Clothes & textiles How can I recycle clothes/textiles? You can recycle clothes and textiles in TRAID recycling banks on request. A charity called TRAID provides colleges and departments can I put in the clothes/textiles recycling bank? You can put shoes, handbags, clothes, coats

  10. AZ Pending Solar Right-of-Way

    E-print Network

    Laughlin, Robert B.

    Light Renewable Power, LLC K5 CSP Trough 18980.87 Yuma FO AZA34665 Solar Reserve I1 CSP Tower 5618.09 Yuma FO AZA34666 Solar Reserve I2 CSP Tower 9862.52 Yuma FO AZA34668 Solar Reserve I3 CSP Tower 5683AR AZ Pending Solar Right-of-Way Applications IZONA STRIP DISTRICT MOHAVE COUNTY Arizona Strip

  11. The 1975 eclipse of AZ Cassiopeiae

    Microsoft Academic Search

    F. Li; S.-Y. Jiang; L.-Z. Shen

    1982-01-01

    Results are reported for uby photoelectric observations of the eclipsing binary AZ Cas during the ascending branch of the system's most recent eclipse. The ephemeris is redetermined; an eclipse duration of 110 days and a period of totality of 94 days are obtained. It is found that the fourth contact time was different in different colors, that the time of

  12. Biochemistry Games: "AZ-Quiz" and "Jeopardy!"

    ERIC Educational Resources Information Center

    Rostejnska, Milada; Klimova, Helena

    2011-01-01

    "AZ-Quiz" and "Jeopardy!" are popular television shows and serve as the basis for in-class games designed to support and diversify chemistry instruction at the high school level. Both games were created in Microsoft PowerPoint, which is an easily accessible and controllable instrument that enables the creation of engaging animation. The use of…

  13. Waste Toolkit A-Z Battery recycling

    E-print Network

    Melham, Tom

    Waste Toolkit A-Z Battery recycling How can I recycle batteries? The University Safety Office make their own arrangements through a registered hazardous waste carrier. Batteries must not be put in normal waste bins or recycling boxes. To recycle batteries, select either option 1 or 2 below: Option 1

  14. Waste Toolkit A-Z Mobile phones

    E-print Network

    Melham, Tom

    Waste Toolkit A-Z Mobile phones How to recycle your mobile phone Recycling your mobile phone makes box or waste bin ­ as they contain hazardous materials Mobiles must be recycled through a hazardous waste company Most mobile phone shops recycle old mobiles, so you can either take your old mobile

  15. Waste Toolkit A-Z Wooden Pallets

    E-print Network

    Melham, Tom

    Waste Toolkit A-Z Wooden Pallets Can I recycle wooden pallets? Yes.Departments and colleges can recycle wooden pallets through a local company called TR Recycling. TR Recycling provides bulky waste Plastics (non-contaminated plastic only ­ contact TR Recycling for details) Soil & green waste Wooden

  16. Olfactory discrimination of complex mixtures of amino acids by the black bullhead Ameiurus melas.

    PubMed

    Valentincic, T; Miklavc, P; Kralj, S; Zgonik, V

    2011-07-01

    On the basis of previous findings of behavioural discrimination of amino acids and on the knowledge of electrophysiology of the catfish (genera Ictalurus and Ameiurus) olfactory organs, behavioural experiments that investigated olfactory discrimination of amino acid mixtures were carried out on the black bullhead Ameiurus melas. Repeated presentations of food-rewarded mixtures released increased swimming activity measured by counting the number of turns >90° within 90 s of stimulus addition. Non-rewarded amino acids and their mixtures released little swimming activity, indicating that A. melas discriminated between the conditioned and the non-conditioned stimuli. Two questions of mixture discrimination were addressed: (1) Are A. melas able to detect components within simple and complex amino acid mixtures? (2) What are the smallest differences between two complex mixtures that A. melas can detect? Three and 13 component mixtures tested were composed primarily of equipotent amino acids [determined by equal electroolfactogram (EOG) amplitude] that contained L-Cys at ×100 the equipotent concentration. Ameiurus melas initially perceived the ternary amino acid mixture as its more stimulatory component alone [i.e. cysteine (Cys)], whereas the conditioned 13 component mixture containing the more stimulatory L-Cys was perceived immediately as different from L-Cys alone. The results indicate that components of ternary mixtures are detectable by A. melas but not those of more complex mixtures. To test for the smallest detectable differences in composition between similar multimixtures, all mixture components were equipotent. Initially, A. melas were unable to discriminate the mixtures of six amino acids from the conditioned mixtures of seven amino acids, whereas they discriminated immediately the mixtures of four and five amino acids from the conditioned mixture. Experience with dissimilar mixtures enabled the A. melas to start discriminating the seven-component conditioned mixture from its six-component counterparts. After fewer than five training trials, A. melas discriminated the mixtures of nine and 10 amino acids from a conditioned mixture of 12 equipotent amino acids; however, irrespective of the number of training trials, A. melas were unable to discriminate the 12 component mixture from its 11 component counterparts. PMID:21722109

  17. Assessment of the "fish tumors or other deformities" beneficial use impairment in brown bullhead (Ameiurus nebulosus): I. Orocutaneous tumors

    USGS Publications Warehouse

    Blazer, V.S.; Rafferty, S.D.; Baumman, P.C.; Smith, S.B.; Obert, E.C.

    2009-01-01

    The "fish tumor or other deformities" beneficial use impairment (BUI) occurs at 9 of the 12 areas of concern (AOC) on Lake Erie. As point sources are mitigated and remediation occurs, AOC are faced with determining delisting criteria. The lack of standardized analyses for this BUI has confounded that process. For orocutaneous tumors, different criteria (presumptive tumors and/or abnormal barbels) and methodology (gross versus microscopic observations) have been used. Hence, this project evaluated tumors at numerous AOC and non-AOC sites and compared methodology. In 1998-2000 the prevalence of presumptive orocutaneous tumors and barbel abnormalities was compared in brown bullhead (Ameiurus nebulosus) collected at eight AOC. The Black (46.7%), Buffalo (29.3%), Cuyahoga (58.9%), and Detroit (26.5%) rivers and Presque Isle Bay (28.6%) had high prevalences of orocutaneous tumors, while the Niagara (10%), Maumee (3.9%) and Ashtabula (4.4%) rivers were lower. From 2002 to 2007 the prevalence of orocutaneous tumors at Presque Isle Bay was consistently near 30%. A variety of non-AOC sites, as potential reference sites, were also monitored during this time. By combining years and sites the prevalence of orocutaneous tumors in bullhead (age 2-12 years) at inland lakes was 6.3%, at Long Point Inner Bay was 8.7%, at other bays and harbors was 14.6% and at tributary sites was 12.5%. Overall, 93% of the raised lesions identified as presumptive tumors grossly were verified as neoplasms microscopically. The prevalence of orocutaneous tumors increased with age at both Presque Isle Bay and Long Point Inner Bay, the sites with the largest sample sizes.

  18. Tumor prevalence and biomarkers of exposure in brown bullhead (Ameiurus nebulosus) from Back River, Furnace Creek, and Tuckahoe River, Maryland

    USGS Publications Warehouse

    Pinkney, A.E.; Harshbarger, J.C.; May, E.B.; Melancon, M.J.

    2004-01-01

    Brown bullheads (Ameiurus nebulosus) were collected from 2 locations near Baltimore, Maryland, Back River and Furnace Creek, and 1 (reference) location, Tuckahoe River, to compare the prevalence of tumors (liver and skin) and visible skin lesions (fin erosion and abnormal barbels). Cytochrome P450 activity measured as ethoxyresorufin-O-deethylase, biliary PAH-like fluorescent metabolites, and fillet contaminant concentrations were determined as indicators of exposure in a randomly selected subset of the fish. There were no significant differences in liver tumor prevalence: Back River = 8% (4/50), Furnace Creek = 0% (0/50), and Tuckahoe River = 2.6% (1/39; p = 0.20, extension of Fishers exact test). Skin tumor prevalence was as follows: Furnace Creek = 12% (6/50), Back River = 8% (4/50), and Tuckahoe River = 0% (0/39; p = 0.063). In the Back River fish, there was a 40% (20/50) prevalence of fin erosion and a 28% (14/50) prevalence of abnormal (shortened, clubbed, or missing) barbels. Fin erosion was not observed in the other collections, and only 10% (5/50) of the Furnace Creek fish had abnormal barbels (p < 0.001 for both lesions). There were statistically significant differences in mean EROD activity, with levels in Furnace Creek and Back River fish approximately twice that found in Tuckahoe River fish. There were also significant differences in mean benzo(a)pyrene-like bile metabolite concentrations: the lowest mean was in the Tuckahoe River fish, 8 times higher in Furnace Creek fish, and 13 times higher in Back River fish. Of the 3 groups, the Back River bullheads appear to be most adversely affected by contaminant exposure because they had the highest prevalence of liver tumors, fin erosion, and abnormal barbels.

  19. Assessment of the "fish tumors or other deformities" beneficial use impairment in brown bullhead (Ameiurus nebulosus): II. Liver neoplasia

    USGS Publications Warehouse

    Blazer, V.S.; Rafferty, S.D.; Baumman, P.C.; Smith, S.B.; Obert, E.C.

    2009-01-01

    Liver pathology of fishes, including neoplastic and preneoplastic lesions, is widely used as an indicator of exposure to anthropogenic contaminants. By definition, the "fish tumor or other deformities" beneficial use impairment (BUI) at Great Lakes Areas of Concern (AOC) includes neoplastic and preneoplastic liver lesions in brown bullhead (Ameiurus nebulosus) or suckers. Unfortunately, adequate guidelines for defining neoplastic and preneoplastic liver lesions or determining rates at unimpacted control sites were not provided and different criteria have been used. In some cases, only neoplastic changes were used to calculate tumor prevalence, in some both neoplastic and preneoplastic changes and in some it is difficult to determine which changes were included. Using standardized criteria, the prevalence of liver neoplasia was compared at eight AOC during 1998-2000. The Cuyahoga River had the highest prevalence (25.0%), while the Maumee River had the lowest (3.9%). The Buffalo (4.8%), Detroit (5.9%), Ashtabula (6.8%), Niagara (7.5%) and Black (8.9%) rivers were intermediate, as was Presque Isle Bay (7.1%). From 2002 to 2007 the prevalence of liver neoplasia at Presque Isle Bay ranged from a low of 2.1% (2002) to a high of 12.0% (2007). Non-AOC sites, as potential reference sites, also were monitored during this time. By combining years and sites, the prevalence of liver neoplasia in bullhead (aged 2 to 12 years) at inland lakes was 0.7%, at bays/harbors was 1.6% and at tributary sites was 4.1%. This is the same trend (inland lakes < bays/harbors < tributaries < Presque Isle Bay) noted for orocutaneous neoplasms.

  20. The extreme Centaur 2013 AZ_{60}

    NASA Astrophysics Data System (ADS)

    Kiss, C.; Horner, J.; Pal, A.; Szakats, R.; Vilenius, E.; Acosta-Pulido, J.; Sarneczky, K.; Szabo, G.; Duffard, R.

    2014-07-01

    2013 AZ_{60} is an extreme Centaur moving on a highly eccentric orbit of e = 0.9922, with a semimajor axis of 1021.09 au, and a perihelion distance of 7.91 au. 2013 AZ_{60} was observed with the PACS camera of the Herschel Space Observatory, and, using these thermal emission measurements, we were able to derive an effective size of 66.5±3.7 km in diameter, and a geometric albedo of p_V=0.026±0.003. Photometric measurements revealed a low-amplitude lightcurve (0.045±0.007mag in the r' band) with a likely full period of P=9.39 h. The dynamical analysis shows that the orbit of 2013 AZ_{60} is highly unstable, with a ˜50 per cent probability that the target is ejected from the Solar System after about 700 kyr. This high level of instability indicates that 2013 AZ_{60} may just have recently been captured to its current orbit. Investigating the total time the target could have spent at small heliocentric distances (< 100 au), it seems to be likely that this has only been at most 100 to 1000 years and it has a low probability that the target could reach Earth-crossing orbits (i.e., < 1 au). As the likely origin of this target is the Oort Cloud, these together suggests a relatively unaltered, pristine surface, in contradiction with the very low albedo (˜2.6 per cent) derived from the thermal infrared measurements which rather indicates an ''extinct cometary'' surface, also in agreement with the photometric colors.

  1. Tank 241-AZ-101 and tank 241-AZ-102, airlift circulator operation vapor sampling and analysis plan

    SciTech Connect

    TEMPLETON, A.M.

    1999-06-02

    This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for vapor samples obtained during the operation of the tank 241-AZ-101 and 241-AZ-102 airlift circulators (ALCs). The purpose of the ALC operation is to support portions of the operational test procedure (OTP) for Project W-030 (OTP-W030-001) and to perform functional test in support of Project W-151. Project W-030 is the 241-A-702 ventilation upgrade project (241-AZ-702) and Project W-151 is the 241-AZ-101 Mixer Pump Test. The functional tests will check the operability of the tank 241-AZ-101 ALCs. Process Memo's No.2E98-082 and No.2E99-001 (LMHC 1999a, LMHC 1999b) direct the operation of the ALCs and the Industrial Hygiene monitoring respectively. A series of tests will be conducted in which the ALCs in tanks 241-AZ-101 and 241-AZ-102 will be operated at different air flow rates. Vapor samples will be obtained to determine constituents that may be present in the tank headspace during ALC operation at tanks 241-AZ-101 and 241-AZ-102 as the waste is disturbed. During the testing, vapor samples will be obtained from the headspace of tanks 241-AZ-101 and 241-AZ-102 via the unused port on the standard hydrogen monitoring system (SHMS). Results will be used to provide the waste feed delivery program with environmental air permitting data for tank waste disturbing activities. Because of radiological concerns, the samples will be filtered for particulates. It is recognized that this may remove some organic compounds.

  2. 78 FR 71493 - Special Local Regulation; Lake Havasu City Christmas Boat Parade of Lights; Colorado River; Lake...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-29

    ...Lake Havasu City Christmas Boat Parade of Lights; Colorado River; Lake Havasu, AZ AGENCY...Lake Havasu City Christmas Boat Parade of Lights on the Colorado River. This modification...Lake Havasu City Christmas Boat Parade of Lights will involve fifty vessels in Lake...

  3. Agrobacterium vitis rezisztencia kialaktsa az iaaM szekvencia segtsgvel

    E-print Network

    Agrobacterium vitis rezisztencia kialakítása az iaaM szekvencia segítségével DIPLOMAMUNKA iaaM(S4) génben 17 4. EREDMÉNYEK és MEGVITATÁSUK 18 4.1. Az A. vitis S4 iaaM szekvencia izolálása 18 4MS4 szekvenciát tartalmazó Agrobacterium vektor létrehozása 20 4.5. A. vitis S4 iaaM mutáns baktérium

  4. ANALYSIS RESULTS FOR BUILDING 241 702-AZ A TRAIN

    SciTech Connect

    DUNCAN JB; FRYE JM; COOKE CA; LI SW; BROCKMAN FJ

    2006-12-13

    This report presents the analyses results for three samples obtained under RPP-PLAN-28509, Sampling and Analysis Plan for Building 241 702-AZ A Train. The sampling and analysis was done in response to problem evaluation request number PER-2004-6139, 702-AZ Filter Rooms Need Radiological Cleanup Efforts.

  5. 241-AZ Farm Annulus Extent of Condition Baseline Inspection

    SciTech Connect

    Engeman, Jason K.; Girardot, Crystal L.; Vazquez, Brandon J.

    2013-05-15

    This report provides the results of the comprehensive annulus visual inspection for tanks 241- AZ-101 and 241-AZ-102 performed in fiscal year 2013. The inspection established a baseline covering about 95 percent of the annulus floor for comparison with future inspections. Any changes in the condition are also included in this document.

  6. Antizyme (AZ) regulates intestinal cell growth independent of polyamines.

    PubMed

    Ray, Ramesh M; Bhattacharya, Sujoy; Bavaria, Mitul N; Viar, Mary Jane; Johnson, Leonard R

    2014-09-01

    Since antizyme (AZ) is known to inhibit cell proliferation and to increase apoptosis, the question arises as to whether these effects occur independently of polyamines. Intestinal epithelial cells (IEC-6) were grown in control medium and medium containing 5 mM difluoromethylornithine (DFMO) to inhibit ODC, DFMO + 5 µM spermidine (SPD), DFMO + 5 µM spermine (SPM), or DFMO + 10 µM putrescine (PUT) for 4 days and various parameters of growth were measured along with AZ levels. Cell counts were significantly decreased and mean doubling times were significantly increased by DFMO. Putrescine restored growth in the presence of DFMO. However, both SPD and SPM when added with DFMO caused a much greater inhibition of growth than did DFMO alone, and both of these polyamines caused a dramatic increase in AZ. The addition of SPD or SPM to media containing DFMO + PUT significantly inhibited growth and caused a significant increase in AZ. IEC-6 cells transfected with AZ-siRNA grew more than twice as rapidly as either control cells or those incubated with DFMO, indicating that removal of AZ increases growth in cells in which polyamine synthesis is inhibited as well as in control cells. In a separate experiment, the addition of SPD increased AZ levels and inhibited growth of cells incubated with DFMO by 50%. The addition of 10 mM asparagine (ASN) prevented the increase in AZ and restored growth to control levels. These results show that cell growth in the presence or absence of ODC activity and in the presence or absence of polyamines depends only on the levels of AZ. Therefore, the effects of AZ on cell growth are independent of polyamines. PMID:24930035

  7. Company City State Contact Info Acacia Research Corporation Newport Beach CA www.acaciaresearch.com

    E-print Network

    McGaughey, Alan

    Company City State Contact Info Acacia Research Corporation Newport Beach CA www. Fountain City CA www.kingston.com Microchip Technology Incorporated Chandler AZ www Milpitas CA www.sandisk.com Silicon Storage Technology, Inc. Sunnyvale CA www.sst.com SMART Modular

  8. 78 FR 3877 - Radio Broadcasting Services; Peach Springs, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-17

    ...MB Docket No. 12-374; RM-11687; DA 12-2072] Radio Broadcasting Services; Peach Springs, AZ AGENCY: Federal...415 and 1.420. List of Subjects in 47 CFR Part 73 Radio, Radio broadcasting. Federal Communications Commission....

  9. Waste Toolkit A-Z Paper confidential paper

    E-print Network

    Melham, Tom

    Waste Toolkit A-Z Paper ­ confidential paper Can I recycle confidential paper? Yes. Departments or colleges interested in monitoring their confidential paper waste tonnages can ask Shred-it to provide data

  10. Waste Toolkit A-Z Can I recycle stationery?

    E-print Network

    Melham, Tom

    Waste Toolkit A-Z Stationery Can I recycle stationery? Yes! You can recycle paper and paper based everyone why the amnesty is taking place (eg: it's part of your zero waste scheme) Provide clearly labelled

  11. ETVS LORND TUDOMNYEGYETEM Az v krnikja A 2009. v

    E-print Network

    Müller, Viktor

    ] Kutatók �jszakája (szeptember 25.) [41] A Magyar Tudomány �nnepe 2009 (november 3­30.) [42] Magyar (október 1. ­ november 15.) [63] Az írás mvészete ­ mvészi írások. Kis magyar oklevéltan. Kiállítás az ELTE

  12. Tumor Prevalence and Biomarkers of Exposure and Response in Brown Bullheads (Ameiurus nebulosus) from the Tidal Potomac River Watershed

    USGS Publications Warehouse

    Pinkney, A.E.; Harshbarger, J.C.; May, E.B.; Melancon, M.J.

    2000-01-01

    Four groups of thirty brown bullheads (Ameiurus nebulosus) were collected from the tidal Potomac River watershed to survey tumor prevalence in relation to contaminant exposure. Fish were obtained from the Quantico embayment, near a Superfund site that released polychlorinated biphenyls (PCBs) and DDT compounds; Neabsco Creek,.a tributary with petroleum inputs from upstream areas and marinas; and the Anacostia River (both in spring and fall),where sediment is contaminated with polynuclear aromatic hydrocarbons (PAHs), PCBs, and organochlorine pesticides. Fish were also collected from the Tuckahoe River, on the Eastern Shore of Maryland, as a reference. Fish were necropsied and examined grossly and histopathologically for skin and liver neoplasms. Cytochrome P450 activity, bile PAH metabolites, and muscle organochlorine pesticide/PCB concentrations were determined in randomly selected individuals. There were significant differences among sites in liver tumor prevalence: Anacostia (spring)-50%, Anacostia (fall)-60%, Neabsco-17%, Quantico-7%, Tuckahoe-10%. Skin tumor prevalences were also significantly different: Anacostia (spring)-37%, Anacostia (fall)-10%, Neabsco-3%, Quantico-3%, Tuckahoe-0%. Tumor prevalences in Anacostia fish were comparable to those at contaminated sites in the Great Lakes. PAH concentrations were higher in Anacostia sediments than at the other sites and there were significantly higher concentrations of PAH metabolites in bile of the Anacostia fish. At present, there are insufficient data, however, to establish a cause-effect linkage with a particular class of contaminants. Tumor surveys in selected species are recommended for monitoring the status and remediation of Regions of Concern and other areas in the Chesapeake Bay watershed.

  13. AZ 400K Developer Process The CEPSR Clean Room stores one gallon bottles of AZ 400K developer solution. They are

    E-print Network

    Kim, Philip

    AZ 400K Developer Process The CEPSR Clean Room stores one gallon bottles of AZ 400K developer and developers. AZ 400K is an odorless, aqueous, inorganic, alkaline solution, free of phosphates and sodium it is recommended to use 1 part 400K and 4 parts DI water; mixed well. Process Note: Variables such as developing

  14. Age 55 or better: active adult communities and city planning.

    PubMed

    Trolander, Judith Ann

    2011-01-01

    Active adult, age-restricted communities are significant to urban history and city planning. As communities that ban the permanent residence of children under the age of nineteen with senior zoning overlays, they are unique experiments in social planning. While they do not originate the concept of the common interest community with its shared amenities, the residential golf course community, or the gated community, Sun Cities and Leisure Worlds do a lot to popularize those physical planning concepts. The first age-restricted community, Youngtown, AZ, opened in 1954. Inspired by amenity-rich trailer courts in Florida, Del Webb added the “active adult” element when he opened Sun City, AZ, in 1960. Two years later, Ross Cortese opened the first of his gated Leisure Worlds. By the twenty-first century, these “lifestyle” communities had proliferated and had expanded their appeal to around 18 percent of retirees, along with influencing the design of intergenerational communities. PMID:22175080

  15. Education Cities

    ERIC Educational Resources Information Center

    Shaked, Haim

    2014-01-01

    In recent years, several cities in Israel have labeled themselves "Education Cities," concentrating on education as their central theme. Employing qualitative techniques, this article aims to describe, define, and conceptualize this phenomenon as it is being realized in three such cities. Findings show that Education Cities differ from…

  16. 14 CFR Appendix to Subpart U of... - Special Flight Rules in the Vicinity of the Grand Canyon National Park, AZ

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...the Vicinity of the Grand Canyon National Park, AZ Appendix to Subpart U of...in the Vicinity of Grand Canyon National Park, AZ Pt. 93, Subpt. U, App...the Vicinity of the Grand Canyon National Park, AZ...

  17. 14 CFR Appendix to Subpart U of... - Special Flight Rules in the Vicinity of the Grand Canyon National Park, AZ

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...the Vicinity of the Grand Canyon National Park, AZ Appendix to Subpart U of...in the Vicinity of Grand Canyon National Park, AZ Pt. 93, Subpt. U, App...the Vicinity of the Grand Canyon National Park, AZ...

  18. 14 CFR Appendix to Subpart U of... - Special Flight Rules in the Vicinity of the Grand Canyon National Park, AZ

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...the Vicinity of the Grand Canyon National Park, AZ Appendix to Subpart U of...in the Vicinity of Grand Canyon National Park, AZ Pt. 93, Subpt. U, App...the Vicinity of the Grand Canyon National Park, AZ...

  19. 14 CFR Appendix to Subpart U of... - Special Flight Rules in the Vicinity of the Grand Canyon National Park, AZ

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...the Vicinity of the Grand Canyon National Park, AZ Appendix to Subpart U of...in the Vicinity of Grand Canyon National Park, AZ Pt. 93, Subpt. U, App...the Vicinity of the Grand Canyon National Park, AZ...

  20. 14 CFR Appendix to Subpart U of... - Special Flight Rules in the Vicinity of the Grand Canyon National Park, AZ

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...the Vicinity of the Grand Canyon National Park, AZ Appendix to Subpart U of...in the Vicinity of Grand Canyon National Park, AZ Pt. 93, Subpt. U, App...the Vicinity of the Grand Canyon National Park, AZ...

  1. Great Zoom into the Grand Canyon, AZ

    NSDL National Science Digital Library

    Greg Shirah

    2003-01-14

    Using data from different spacecraft and some powerful computer technology, visualizers at the Goddard Space Flight Center present you with a collection of American cities in a way you have never seen them before. Starting with our camera high above the Earth, we rush in towards the surface at what would be an impossible speed for any known vehicle. Passing though layers of atmosphere, the colors of our destinations shimmer with their own unique characteristics, and suddenly we find ourselves floating in virtual space just above the ground.

  2. Arizonans on Edge...So Why Not Involved? AZ Views. Volume 2, Issue 1

    ERIC Educational Resources Information Center

    Morrison Institute for Public Policy, Arizona State University, 2009

    2009-01-01

    What a difference a year makes. In June 2008, "AZ Views" reported that "Arizonans have a strong sense of job security, despite the national economic slump and the state's budget crisis." That is no longer true, as this edition of "AZ Views" shows, and Arizona's economic situation arguably is the best example of the worst case.This issue of "AZ…

  3. Benzo(a)pyrene exposure causes adaptive changes in p53 and CYP1A gene expression in Brown bullhead (Ameiurus nebulosus).

    PubMed

    Williams, R; Hubberstey, A V

    2014-11-01

    The Brown bullhead (Ameiurus nebulosus) is able to survive and reproduce in high levels of environmentally contaminated areas of the Great Lakes. The purpose of this study was to establish whether there are adaptive genetic/molecular changes occurring in these fish that allow for their survival. Expression of a cell cycle regulator, p53 and the toxin metabolizing protein, CYP1A were measured in liver tissue from bullhead caught from either clean or contaminated areas of Lake Erie and surrounding areas. Wild caught fish and F1 raised offspring (whose parents originated from clean and contaminated sites) were used to measure endogenous gene expression levels. Results revealed that endogenous expression of p53 was on average 6.6× higher in contaminated fish than in fish caught from clean sites. Interestingly, when fed benzo(a)pyrene (BaP)-treated food, p53 expression increased 0.2× in clean fish and decreased 2.6× in contaminated fish. Endogenous CYP1A expression was not detectable in clean fish and low in contaminated fish. Upon exposure to BaP-treated food, CYP1A expression increased in both clean and contaminated fish, although at a higher rate in clean fish. Furthermore, when fish were cleared and then re-exposed to BaP, CYP1A expression increased from basal levels at a higher rate in clean versus contaminated fish. CYP1A and p53 expression in F1 offspring was similar to wild caught fish at the endogenous level and when fed BaP treated food. Results suggest that fish in contaminated regions may be implementing an adaptive response to severe environmental stress by maintaining high expression of p53 and low expression of CYP1A; thus lending increased protection to cells and decreasing the potential amount of carcinogens produced by contaminant metabolism. PMID:25259779

  4. Assessing Exposure and Experience with Extreme Heat in Phoenix, AZ

    E-print Network

    Hall, Sharon J.

    Lasting Heat Waves in the 21st Century. Science 305:994-997. More people die from extreme heat than allAssessing Exposure and Experience with Extreme Heat in Phoenix, AZ Darren M Ruddell, Sharon L (2005) Heat-Related Mortality ­ Arizona, 1993-2002 and United States, 1979-2002. Morbidity & Mortality

  5. Klmavltozsok s az aktivista sz kritikja Rcz Zoltn

    E-print Network

    Rácz, Zoltán

    (Intergovernmental Panel on Climate Change) 1990 (forrás nélkül) IPCC 2001 (Mann et al.) Mann et al., PNAS, 13252 (2008) #12;Az utolsó 150 év 1850 1900 1950 2000 IPCC 2007 A kis jégkorszak vége? #12;Interpretációk egy témára Myth #2: Global warming stopped ten years ago. Climate is not weather. The climate is the multi

  6. Dividend Homes Commercial Building 1993 Frontage Rd, Sierra Vista AZ

    E-print Network

    Restrepo, Juan M.

    and forth, creating "sound waves" that can be heard (presumably by humans). One way to picture own ear drum, which moves in harmony with the waves, and our brain "hears" the sound the bass drum, Tucson AZ January 14, 2012 #12;Sound & Noise Generation, Propagation & Reduction Kevin Surace Quiet

  7. Waste Toolkit A-Z Can I recycle paper cups?

    E-print Network

    Melham, Tom

    Waste Toolkit A-Z Paper cups Can I recycle paper cups? Yes. Paper cups can be recycled in the Grundon recycling boxes. Do not leave dregs of drink in them, as this will contaminate the recycling box. Although it is good to recycle paper cups, it is more sustainable to use china cups that can be washed

  8. Waste Toolkit A-Z How can I recycle computers?

    E-print Network

    Melham, Tom

    Waste Toolkit A-Z Computers How can I recycle computers? The University policy for computer disposal is outlined in detail, here: www.ict.ox.ac.uk/oxford/disposal/index.xml Recycle/reuse 1. Before If the computer can't be reused, it should be recycled by an authorised contractor who will guarantee that all

  9. 75 FR 76293 - Radio Broadcasting Services; Peach Springs, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-08

    ...DA 10-2212; MB Docket No. 09-204; RM-11580] Radio Broadcasting Services; Peach Springs, AZ AGENCY: Federal...a)(1)(A). List of Subjects in 47 CFR Part 73 Radio, Radio broadcasting. 0 As stated in the preamble, the...

  10. Kyou Email Blackboard Enroll & Pay KU Home A-Z

    E-print Network

    Kyou Email Blackboard Enroll & Pay KU Home A-Z top A GREAT PLACE TO BE A CHAMPION University of Kansas KU Student Profile Fall 2011 Table of Contents Home Academic Information ACT/Converted SAT Scores/Graduate Enrollment II Average Age Full-Time/Part-Time Residency School Top 10 Enrollments Kansas Counties Kansas High

  11. Mixer pump test plan for double shell tank AZ-101

    SciTech Connect

    STAEHR, T.W.

    1999-05-12

    Mixer pump systems have been chosen as the method for retrieval of tank wastes contained in double shell tanks at Hanford. This document describes the plan for testing and demonstrating the ability of two 300 hp mixer pumps to mobilize waste in tank AZ-101. The mixer pumps, equipment and instrumentation to monitor the test were installed by Project W-151.

  12. nature.com Publications A-Z index

    E-print Network

    Liu, Taosheng

    nature.com Publications A-Z index Browse by subject My account Submit manuscript Register.comjournal homeadvance online publicationArticlefull text Previous articleNext article Nature Photonics | Article Science jobs from naturejobs Developer r Nature Publishing Group r London, UK Post a free job More

  13. Az orphan drug problémakör egészség-gazdaságtani megközelítése

    Microsoft Academic Search

    Boncz Imre

    2008-01-01

    A ritka betegségek azon betegségeket jelölik, melyek alacsony gyakorisággal fordulnak elô, vagyis kisebb be- tegpopulációt érint megjelenésük. Tanulmányunkban át- tekintést kívánunk nyújtani a ritka betegségek gyógysze- res kezelésének (orphan drug) speciális egészség-gaz- daságtani és ártámogatási vonatkozásairól. Jó közelítés- sel elmondható, hogy az alacsonyabb prevalencia egy- értelmûen a magasabb árral jár együtt. Ez egyben azt is jelenti, hogy a költség-hatékonysági érték

  14. Waste Toolkit A-Z Electrical (non-hazardous)

    E-print Network

    Melham, Tom

    Waste Toolkit A-Z Electrical (non-hazardous) What are non-hazardous electrical items? Non-hazardous electrical items are often referred to as `non-haz WEEE'. WEEE stands for Waste Electrical and Electronic Equipment, after the Waste Electrical and Electronic Equipment (WEEE) Directive, which came into force

  15. Waste Toolkit A-Z Cartridges Reclaim-IT

    E-print Network

    Melham, Tom

    Waste Toolkit A-Z Cartridges ­ Reclaim-IT How can I recycle cartridges? You can recycle cartridges in the office products industry throughout the UK. Reclaim-IT is a fully licensed Waste Carrier (Environment collection, so it's cheaper than putting cartridges in the waste bin, destined for landfill. Reclaim-IT helps

  16. Waste Toolkit A-Z Plastic cups Grundon

    E-print Network

    Melham, Tom

    Waste Toolkit A-Z Plastic cups ­ Grundon Can I recycle plastic cups? Yes, you can recycle plastic be recycled in the Grundon recycling box and must go in the landfill waste bin. PET Polyethylene Terepthalate Density Polyethylene X Othere All other resins and multi-materials X Can I reduce plastic cup waste? It

  17. Cities Guide

    NSDL National Science Digital Library

    From The Economist, their Cities Guide offers practical information ranging from accommodations to insider tips on getting around various US and world cities. A very nice touch are areas like the City Briefing section (top news stories, history pieces, and other tidbits) and the Being There area (subtopics include how to kill an hour and gifts to take home). City Guide also contains sections on cultural events, shopping, history, facts, and much more. [REB].

  18. Tensile city

    E-print Network

    Chakkour, Mario Henri

    1987-01-01

    Tensile City is a story that provides the answer to the following question: II If we were to leap forward in time and visit a city of the future, what would learn about our contemporary city ? II The story unfolds when ...

  19. Historic Cities

    NSDL National Science Digital Library

    Jointly sponsored by the Historic Cities Center within the Department of Geography at Hebrew University and the Jewish National and University Library, the Historic Cities Web site is intended to contain maps, literature, documents, books, and other relevant material concerning the past, present, and future of historic cities While some of these documents and ephemera are still forthcoming to the site, visitors will find a wide array of historic city maps and views dating from 1486 to 1720. The scanned maps are searchable alphabetically, by date, and by individual cartographer. Additionally, a bit of information is provided about each cartographer. Overall, the site contains close to two hundred individual city maps and renderings, ranging from medieval Heidelberg to Casablanca. For persons with an interest in urban morphology and the history of cartography, the Historic Cities site will be a good place to start.

  20. City Mayors

    NSDL National Science Digital Library

    Drawing on the expertise of a team of editors who reside in Britain, Germany, Spain, Mexico, France, and a number of other countries, the City Mayors organization is an "international network of professionals working to promote strong cities and good local government." Their website takes on all of the important urban issues of the day, including governance, affordable housing, sustainable development, transportation, and a number of other pressing issues. On their homepage, visitors will find links to recent news stories from cities around the world and direct links to thematic sections such as business, finance, environment, and development. One section that should not be missed is the "City Rankings" area, which includes helpful lists of the largest cities in the world by land area, population and density, along with a list of the most expensive cities in the world.

  1. H2A.Z.2.2 is an alternatively spliced histone H2A.Z variant that causes severe nucleosome

    E-print Network

    Pfeifer, Holger

    H2A.Z.2.2 is an alternatively spliced histone H2A.Z variant that causes severe nucleosome Bielmeier2 , Marco Bocola3 , H. Christian Eberl4 , Wolfgang Kuegel5 , Ju¨ rgen Neumann2 , Elisabeth Kremmer6,7, * 1 Department of Molecular Biology, Adolf-Butenandt-Institute, Ludwig-Maximilians-University Munich

  2. The Corrosion Protection of Magnesium Alloy AZ31B

    NASA Technical Reports Server (NTRS)

    Danford, M. D.; Mendrek, M. J.; Mitchell, M. L.; Torres, P. D.

    1997-01-01

    Corrosion rates for bare and coated Magnesium alloy AZ31B have been measured. Two coatings, Dow-23(Trademark) and Tagnite(Trademark), have been tested by electrochemical methods and their effectiveness determined. Electrochemical methods employed were the scanning reference electrode technique (SRET), the polarization resistance technique (PR) and the electrochemical impedance spectroscopy technique (EIS). In addition, general corrosion and stress corrosion methods were employed to examine the effectiveness of the above coatings in 90 percent humidity. Results from these studies are presented.

  3. szgI LszL Az Etvs Lornd

    E-print Network

    Müller, Viktor

    ELTE adja ki a legtöbb PhD oklevelet. Itt jött létre az ország els botanikus kertje (1771), a magyar, a legnépszerbb magyar egyetem, ahol a legtöbben szeretnének tanul- ni és ahová a legnehezebb bekerülni. Ajánlom e

  4. DDT_ckiss_3: The "supercomet" candidate 2013 AZ60

    NASA Astrophysics Data System (ADS)

    Kiss, C.

    2013-03-01

    We propose to observe 2013 AZ 60, a newly discovered object on a highly eccentric orbit. Scan-map observations with the PACS photometer camera can unravel the main characteristics of the target including size, albedo and surface thermal properties. With these measurements we will be able to determine whether this object is an extinct comet or may rather be similar to 2012 DR30, a recently studied object an a similarly eccentric orbit that show surface properites more similar to that of main belt asteroids. As 2013 AZ60 has a likely origin in the Oort cloud but shows no cometary activity, with these measurements we have the rare opportunity to investigate an object from the least explored and furthest region of our Solar System. 2013 AZ60, as well as 2012 DR30, likely belong to a new class of large solar system objects (in the order of 100km in size) that could be potential sources or late representatives of the intrinsically brightest comets ever seen during human history.

  5. Formability study of magnesium alloy AZ31B

    NASA Astrophysics Data System (ADS)

    Liu, Z. G.; Lasne, P.; Massoni, E.

    2011-08-01

    The main aim of this paper is to study the formability of the AZ31B magnesium alloy at various temperature and strain rates. The tensile tests are performed to describe the rheological behavior of material, and the constitutive law is identified with Voce law [1], which contains a softening item. The law is proved effectiveness by fitting the equation with the experimental data. Nakazima experiments with hemispherical punch have been performed at CEMEF on a hydraulic testing machine. Six strain paths are selected by performing various sample geometries [2]. The AramisOptical strain measurement system has been used to obtain principle forming limit strain. The Forming Limit Diagram (FLD) is obtained by the critical point on the specimen surface at various temperatures. It is shown that the forming limit curve is higher at high temperature. Based on the Voce law model, finite element simulations of deep drawing test have been done with the commercial finite element code FORGE® in order to investigate the feasibility of hot stamping process for AZ31. In the simulation, the punch load and the thickness distributions have been studied. Meanwhile, the cross-shaped cup deep drawing simulations have been conducted with the data provided in the conference Website. The similar conclusion are obtained that the formability of AZ31 improve at high temperature and the simulation is effective in hot stamping processing. The study results are helpful for the application of the stamping technology for the magnesium alloy sheet [3].

  6. City Play.

    ERIC Educational Resources Information Center

    Dargan, Amanda; Zeitlin, Steve

    2000-01-01

    Today, fewer city blocks preserve the confidence of lifestyle and urban geography that sustain traditional games and outdoor play. Large groups of children choosing sides and organizing Red Rover games are no longer commonplace. Teachers must encourage free play; urban planners must build cities that are safe play havens. (MLH)

  7. ANP32E is a histone chaperone that removes H2A.Z from chromatin.

    PubMed

    Obri, Arnaud; Ouararhni, Khalid; Papin, Christophe; Diebold, Marie-Laure; Padmanabhan, Kiran; Marek, Martin; Stoll, Isabelle; Roy, Ludovic; Reilly, Patrick T; Mak, Tak W; Dimitrov, Stefan; Romier, Christophe; Hamiche, Ali

    2014-01-30

    H2A.Z is an essential histone variant implicated in the regulation of key nuclear events. However, the metazoan chaperones responsible for H2A.Z deposition and its removal from chromatin remain unknown. Here we report the identification and characterization of the human protein ANP32E as a specific H2A.Z chaperone. We show that ANP32E is a member of the presumed H2A.Z histone-exchange complex p400/TIP60. ANP32E interacts with a short region of the docking domain of H2A.Z through a new motif termed H2A.Z interacting domain (ZID). The 1.48?Å resolution crystal structure of the complex formed between the ANP32E-ZID and the H2A.Z/H2B dimer and biochemical data support an underlying molecular mechanism for H2A.Z/H2B eviction from the nucleosome and its stabilization by ANP32E through a specific extension of the H2A.Z carboxy-terminal ?-helix. Finally, analysis of H2A.Z localization in ANP32E(-/-) cells by chromatin immunoprecipitation followed by sequencing shows genome-wide enrichment, redistribution and accumulation of H2A.Z at specific chromatin control regions, in particular at enhancers and insulators. PMID:24463511

  8. 241-AZ Tank Farm Construction Extent of Condition Review for Tank Integrity

    SciTech Connect

    Barnes, Travis J.; Boomer, Kayle D.; Gunter, Jason R.; Venetz, Theodore J.

    2013-07-30

    This report provides the results of an extent of condition construction history review for tanks 241-AZ-101 and 241-AZ-102. The construction history of the 241-AZ tank farm has been reviewed to identify issues similar to those experienced during tank AY-102 construction. Those issues and others impacting integrity are discussed based on information found in available construction records, using tank AY-102 as the comparison benchmark. In the 241-AZ tank farm, the second DST farm constructed, both refractory quality and tank and liner fabrication were improved.

  9. Sensitivity of summer climate to anthropogenic land-cover change over the Greater Phoenix, AZ, region

    USGS Publications Warehouse

    Georgescu, M.; Miguez-Macho, G.; Steyaert, L.T.; Weaver, C.P.

    2008-01-01

    This work evaluates the first-order effect of land-use/land-cover change (LULCC) on the summer climate of one of the nation's most rapidly expanding metropolitan complexes, the Greater Phoenix, AZ, region. High-resolution-2-km grid spacing-Regional Atmospheric Modeling System (RAMS) simulations of three "wet" and three "dry" summers were carried out for two different land-cover reconstructions for the region: a circa 1992 representation based on satellite observations, and a hypothetical land-cover scenario where the anthropogenic landscape of irrigated agriculture and urban pixels was replaced with current semi-natural vegetation. Model output is evaluated with respect to observed air temperature, dew point, and precipitation. Our results suggest that development of extensive irrigated agriculture adjacent to the urban area has dampened any regional-mean warming due to urbanization. Consistent with previous observationally based work, LULCC produces a systematic increase in precipitation to the north and east of the city, though only under dry conditions. This is due to a change in background atmospheric stability resulting from the advection of both warmth from the urban core and moisture from the irrigated area. ?? 2008 Elsevier Ltd. All rights reserved.

  10. 78 FR 17869 - Safety Zone; Desert Storm Shootout; Lake Havasu, Lake Havasu City, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-25

    ...transit or anchor in a portion of the Colorado River from 8 a.m. to 6 p.m. on...the waters of Lake Havasu on the Colorado River and is bound by the following coordinates...and local, state, or federal law enforcement vessels who have...

  11. 78 FR 17097 - Safety Zone; Lake Havasu Triathlon; Lake Havasu City, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-20

    ...navigable waters of Lake Havasu and the London Bridge Channel for the Lake Havasu Triathlon...of 1500 meters in Lake Havasu and the London Bridge Channel. The course requires a...restricting vessel traffic within the north London Bridge Channel and a small portion...

  12. Recycle City

    NSDL National Science Digital Library

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

  13. Open City

    NSDL National Science Digital Library

    Are you interested in improving civic culture and knowledge with apps? If so, you will be delighted to learn about the Open City site. The Open City folks are a group of programmers, citizen activists, and policy types that create apps with open data in order "to improve transparency and understanding of our government." Chicagoans can stop by the Merchandise Mart to meet up and work with Open City in person. Everyone else can check out the Projects page to view apps like "Chicago Councilmatic," "How's Business?" and "Crime in Chicago." Each of these apps takes open source data from the city of Chicago and other organizations to create tools designed to help decision makers, journalists, and scholars with their various projects. The site also contains information about the people behind the organization and press releases about their work.

  14. Modelling of Superplastic Forming of AZ31 Magnesium Alloy

    SciTech Connect

    Giuliano, G. [University of Cassino, Department of Industrial Engineering, via Di Biasio 43, 03043 Cassino (Italy)

    2011-01-17

    In this study the constitutive equation of the superplastic AZ31 magnesium-based alloy is modelled by the power law relationship between the stress, the strain and the strain-rate and an accurate procedure for determining the constants of the material is presented. Moreover, the problem of optimizing the pressure-time load curve of a free forming process is investigated and resolved by means of a pressure jump forming process. The experimental tests, carried out to support the finite-element modelling, have shown good agreement between the numerical results and the experimental data.

  15. Mixer pump test plan for double shell tank AZ-101

    SciTech Connect

    Symons, G.A.; Staehr, T.W., Westinghouse Hanford

    1996-06-01

    Westinghouse Hanford Company has undertaken the task to develop and demonstrate a method of retrieval for double-shell tank (DST)waste. Mixer pumps were chosen as the planned method of retrieval for the DSTs, based on engineering technology studies,past experience with hydraulic sluicing at the Hanford Site, and experience with mixer pumps at the Westinghouse Savannah River Site. This document outlines a test plan to demonstrate the ability of two 300 hp mixer pumps installed in the AZ-101 tank to mobilize waste.

  16. 14 CFR Special Federal Aviation... - 2-Special Flight Rules in the Vicinity of the Grand Canyon National Park, AZ

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...the Vicinity of the Grand Canyon National Park, AZ Federal Special Federal...the Vicinity of the Grand Canyon National Park, AZ Section 1. Applicability...designated as the Grand Canyon National Park Special Flight Rules Area: That...

  17. 14 CFR Special Federal Aviation... - 2-Special Flight Rules in the Vicinity of the Grand Canyon National Park, AZ

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...the Vicinity of the Grand Canyon National Park, AZ Federal Special Federal...the Vicinity of the Grand Canyon National Park, AZ Section 1. Applicability...designated as the Grand Canyon National Park Special Flight Rules Area: That...

  18. 14 CFR Special Federal Aviation... - 2-Special Flight Rules in the Vicinity of the Grand Canyon National Park, AZ

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...the Vicinity of the Grand Canyon National Park, AZ Federal Special Federal...the Vicinity of the Grand Canyon National Park, AZ Section 1. Applicability...designated as the Grand Canyon National Park Special Flight Rules Area: That...

  19. 14 CFR Special Federal Aviation... - 2-Special Flight Rules in the Vicinity of the Grand Canyon National Park, AZ

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...the Vicinity of the Grand Canyon National Park, AZ Federal Special Federal...the Vicinity of the Grand Canyon National Park, AZ Section 1. Applicability...designated as the Grand Canyon National Park Special Flight Rules Area: That...

  20. 14 CFR Special Federal Aviation... - 2-Special Flight Rules in the Vicinity of the Grand Canyon National Park, AZ

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...the Vicinity of the Grand Canyon National Park, AZ Federal Special Federal...the Vicinity of the Grand Canyon National Park, AZ Section 1. Applicability...designated as the Grand Canyon National Park Special Flight Rules Area: That...

  1. ABOUT CALENDAR FEES ENROLLMENT RECORDS University Home MyUCSC People Calendars A-Z Index

    E-print Network

    California at Santa Cruz, University of

    ABOUT CALENDAR FEES ENROLLMENT RECORDS University Home MyUCSC People Calendars A-Z Index OFFICE OF THE REGISTRAR Chancellor's Welcome About Fields of Study Calendar Undergraduate Expenses Undergraduate Admission CALENDAR FEES ENROLLMENT RECORDS University Home MyUCSC People Calendars A-Z Index OFFICE OF THE REGISTRAR

  2. Hot cracking in tungsten inert gas welding of magnesium alloy AZ91D

    E-print Network

    Zhou, Wei

    Hot cracking in tungsten inert gas welding of magnesium alloy AZ91D W. Zhou*, T. Z. Long and C. K ductility, and the HAZ was found to be the `weakest link'. Keywords: Magnesium alloy, AZ91D, TIG welding, Hot cracking, Liquation, Fracture Introduction Magnesium alloys have high strength/weight ratio

  3. Evaluation of microstructural eects on corrosion behaviour of AZ91D magnesium

    E-print Network

    Zhou, Wei

    Evaluation of microstructural eects on corrosion behaviour of AZ91D magnesium alloy Rajan Ambat(OH)2 with small amounts b phase, magnesium-aluminium oxide and MgH2 while for die-cast, the product: Magnesium alloys; AZ91D; Ingot; Die-cast; Microstructure; Corrosion 0010-938X/00/$ - see front matter 7 2000

  4. In vitro Study on Biodegradable AZ31 Magnesium Alloy Fibers Reinforced PLGA Composite

    E-print Network

    Zheng, Yufeng

    21 March 2013] AZ31 magnesium alloy fibers reinforced poly(lactic-co-glycolic acid) (PLGA) composites materials have never been reported to our knowledge. Poly(lactic-co-glycolic acid) (PLGA) is the copolymerIn vitro Study on Biodegradable AZ31 Magnesium Alloy Fibers Reinforced PLGA Composite Y.H. Wu1) , N

  5. Functional analysis of the histone variant H2A.Z during lineage commitment

    E-print Network

    Surface, Lauren E. (Lauren Elizabeth)

    2014-01-01

    remained enigmatic. In this thesis, we dissect the role of H2A.Z during lineage commitment. In particular, we focused on the Polycomb-mediated mono-ubiquitylation of H2A.Z. We found that this modification regulates the ...

  6. Diffusion of Ag implanted into the AZ1350 photoresist

    NASA Astrophysics Data System (ADS)

    Soares, M. R. F.; Amaral, L.; Behar, M.; Fink, D.

    2002-05-01

    In the present work we report Ag diffusion results in the photoresist AZ1350. We have implanted Ag into AZ1350 films at very low energy ( E=30 keV) and increasing fluences, ?=10 12 at/cm 2, 5×10 12 and 5×10 13 Ag/cm 2. Annealing was performed in the 150-270 °C temperature range and the as-implanted and diffused depth profiles were analyzed using the Rutherford backscattering technique. For the lowest implantation fluence the results show a regular atomic diffusion characterized by an activation energy of Ea=650 meV. This feature shows that in this particular case we have minimized the radiation damage introduced by the implantation process and avoided the cluster formation. Instead for ?=5×10 12 Au/cm 2 it is already possible to observe the effects of the radiation damage on the diffusion process. However even for the highest implanted fluence no evidence of cluster formation and diffusion is observed.

  7. The DREAM complex promotes gene body H2A.Z for target repression

    PubMed Central

    Latorre, Isabel; Chesney, Michael A.; Garrigues, Jacob M.; Stempor, Przemyslaw; Appert, Alex; Francesconi, Mirko; Strome, Susan

    2015-01-01

    The DREAM (DP, Retinoblastoma [Rb]-like, E2F, and MuvB) complex controls cellular quiescence by repressing cell cycle genes, but its mechanism of action is poorly understood. Here we show that Caenorhabditis elegans DREAM targets have an unusual pattern of high gene body HTZ-1/H2A.Z. In mutants of lin-35, the sole p130/Rb-like gene in C. elegans, DREAM targets have reduced gene body HTZ-1/H2A.Z and increased expression. Consistent with a repressive role for gene body H2A.Z, many DREAM targets are up-regulated in htz-1/H2A.Z mutants. Our results indicate that the DREAM complex facilitates high gene body HTZ-1/H2A.Z, which plays a role in target gene repression. PMID:25737279

  8. The DREAM complex promotes gene body H2A.Z for target repression.

    PubMed

    Latorre, Isabel; Chesney, Michael A; Garrigues, Jacob M; Stempor, Przemyslaw; Appert, Alex; Francesconi, Mirko; Strome, Susan; Ahringer, Julie

    2015-03-01

    The DREAM (DP, Retinoblastoma [Rb]-like, E2F, and MuvB) complex controls cellular quiescence by repressing cell cycle genes, but its mechanism of action is poorly understood. Here we show that Caenorhabditis elegans DREAM targets have an unusual pattern of high gene body HTZ-1/H2A.Z. In mutants of lin-35, the sole p130/Rb-like gene in C. elegans, DREAM targets have reduced gene body HTZ-1/H2A.Z and increased expression. Consistent with a repressive role for gene body H2A.Z, many DREAM targets are up-regulated in htz-1/H2A.Z mutants. Our results indicate that the DREAM complex facilitates high gene body HTZ-1/H2A.Z, which plays a role in target gene repression. PMID:25737279

  9. Criminal Victimization And Perceptions Of Community Safety In 12 Cities, 1998

    NSDL National Science Digital Library

    This report, recently released by the Bureau of Justice Statistics, provides city-level survey data on crime victimization in twelve US cities: Chicago, IL; Kansas City, MO; Knoxville, TN; Los Angeles, CA; Madison, WI; New York, NY; San Diego, CA; Savannah, GA; Spokane, WA; Springfield, MA; Tucson, AZ; and Washington, DC. The report presents data on community policing, the rates at which residents are victimized by crime, citizens' perceptions of crimes and their attitudes toward their community and local law enforcement agencies. The report is available in .pdf or ASCII format. Users may also download a compressed file (.zip) containing all the survey data spreadsheets (.wk1).

  10. City Lore

    NSDL National Science Digital Library

    Based in New York, the City Lore organization is a nonprofit organization devoted to promoting the cultural heritage of the city through a variety of programs and events. Two online exhibits dealing with the Puerto Rican Day parade and the making of lace highlight some of their more recent work. A resources link on the site leads to several helpful articles that highlight the study of urban culture and folklore, along with a list of related links. One of the best parts of the site is an area dealing with New York Favorites, which is essentially a list of places and sights that local New Yorkers have submitted to the site. Finally, the site contains City Lore's online People's Hall of Fame, which recognizes the life-long contributions of persons who have dedicated themselves to the maintenance and practice of a number of folkways and traditions.

  11. Glucose tolerance and peripheral glucose utilization in rainbow trout (Oncorhynchus mykiss), American eel (Anguilla rostrata), and black bullhead catfish (Ameiurus melas).

    PubMed

    Legate, N J; Bonen, A; Moon, T W

    2001-04-01

    This study tests the hypothesis that glucose tolerance in fish is related to nutrient preference and is correlated with white muscle glucose transporter and phosphorylation (hexokinase) activities. Glucose clearance was investigated in the carnivorous rainbow trout (Oncorhynchus mykiss) and American eel (Anguilla rostrata) (feeding and fasting) and the omnivorous black bullhead catfish (Ameiurus melas). Glucose tolerance was assessed by an intravenous glucose tolerance test, injecting 250 mg glucose/kg body weight and tracking blood glucose concentrations over 24 h. Both feeding eel and feeding catfish returned plasma glucose levels to baseline within 60 min of glucose injection. Glucose values remained elevated for more than 360 min in both the food-deprived eel and the feeding rainbow trout. Glucose transport studies in white muscle membrane vesicles provided evidence for the presence of a stereospecific, saturable glucose transporter in all three species. Affinity constants (K(m)) ranged from 8 to 14 mM while V(max) values ranged from 75 to 150 pmol/s/mg protein. Neither kinetic parameter differed significantly between species. Cytochalasin B and phloretin did not significantly inhibit glucose transport, implying that these transporters are unlike the mammalian muscle glucose transporters (GLUT). In fact, Northern and Western blot analyses of mRNA and protein from white and red muscles and heart did not detect a mammalian-type GLUT-1 or -4 in any of the species examined. Glucose phosphorylation indicated the presence of a hexokinase activity (low K(m) enzyme) but again there were no differences in kinetic parameters between species. These studies demonstrate that glucose tolerance in fish is species-dependent but none of the parameters examined clearly differentiate between the species examined. Certainly a stereospecific glucose transporter exists in white skeletal muscle of the fish studied but no molecular or kinetic similarities to the mammalian GLUTs were found. Whether these transporters are insulin-sensitive or contribute to glucose tolerance requires further molecular characterization. PMID:11352553

  12. City Image & City Design: The Lynchian Tradition

    E-print Network

    Ishii, Hiroshi

    , vast space, and the enormous future." --What Time is This Place? 1972 Imageability City form #12 and environmental performance (Christopher Zegras) and connections among city design, public policy35 City Image & City Design: The Lynchian Tradition Most of Kevin Lynch's ideas about city form

  13. City 2020+

    NASA Astrophysics Data System (ADS)

    Schneider, C.; Buttstädt, M.; Merbitz, H.; Sachsen, T.; Ketzler, G.; Michael, S.; Klemme, M.; Dott, W.; Selle, K.; Hofmeister, H.

    2010-09-01

    This research initiative CITY 2020+ assesses the risks and opportunities for residents in urban built environments under projected demographic and climate change for the year 2020 and beyond, using the City of Aachen as a case study. CITY 2020+ develops scenarios, options and tools for planning and developing sustainable future city structures. We investigate how urban environment, political structure and residential behavior can best be adapted, with attention to the interactions among structural, political, and sociological configurations and with their consequences on human health. Demographers project that in the EU-25-States by 2050, approximately 30% of the population will be over age 65. Also by 2050, average tem¬peratures are projected to rise by 1 to 2 K. Combined, Europe can expect enhanced thermal stress and higher levels of particulate matter. CITY 2020+ amongst other sub-projects includes research project dealing with (1) a micro-scale assessment of blockages to low-level cold-air drainage flow into the city centre by vegetation and building structures, (2) a detailed analysis of the change of probability density functions related to the occurrence of heat waves during summer and the spatial and temporal structure of the urban heat island (UHI) (3) a meso-scale analysis of particulate matter (PM) concentrations depending on topography, local meteorological conditions and synoptic-scale weather patterns. First results will be presented specifically from sub-projects related to vegetation barriers within cold air drainage, the assessment of the UHI and the temporal and spatial pattern of PM loadings in the city centre. The analysis of the cold air drainage flow is investigated in two consecutive years with a clearing of vegetation stands in the beginning of the second year early in 2010. The spatial pattern of the UHI and its possible enhancement by climate change is addressed employing a unique setup using GPS devices and temperature probes fixed to several public transport units running all across the city. This is accompanied by an analysis of probability density functions (PDF) for heat waves based on recent climate data and climate projections. A dense net of 40 PM measurement sites is operated in order to obtain the spatial pattern of PM concentration as depending on meteorological condition and location. It is lined out how this climate related sub-projects interact with investigations on social networks, governance issues, buildings structure development and health outcome. Related to the later the chemical composition of PM is analyzed in more detail and related to the spatial patterns of health deficiencies. At a later stage City2020+ will propose new strategies based on cooperation from the fields of medicine, geography, sociology, history, civil engineering, and architecture for adapting the city for future needs. The Project CITY 2020+ is part of the interdisciplinary Project House HumTec (Human Sciences and Technology) at RWTH Aachen University funded by the Excellence Initiative of the German federal and state governments through the Deutsche Forschungsgemeinschaft (German Research Foundation, DFG).

  14. Air composition over Siberian cities.

    NASA Astrophysics Data System (ADS)

    Belan, B. D.; Ivlev, G. A.; Kozlov, A. S.; Marinaite, I. I.; Peneko, V. V.; Simonenkov, D. V.; Fofonov, A. V.; Khodzher, T. V.; Arshinov, M. Yu.

    2009-04-01

    It is typical feature of Siberian cities that the quality of the atmosphere significantly depends on the climate conditions. During more than half of year, stable atmospheric stratification dominates over Siberia with temperature inversions, favoring accumulation of pollutants of different origin in the lower atmospheric layers. In addition to severe climatic conditions, modern industrial cities experience increasingly intensifying effect of anthropogenic factors on the environment and human health. Urban conditions give rise to distinct mesoclimates favoring accumulation of pollutants. In this case, natural and anthropogenic systems (power-generating and industrial objects, traffic, etc.) interact very closely. In this paper we present experimental results of the study the local air circulation effect on air composition of industrial cities of Siberian region. In our studies we have used AKV-2 mobile station, designed at the Institute of Atmospheric Optics SB RAS. The instrumentation of the station provides measurements of air temperature and humidity, wind speed and direction, total solar radiation; aerosol number density in two size ranges (0.4-10 microns by use of a modernized AZ-6 optical particle counter, and from 3 to 200 nm with a diffusion spectrometer of aerosols), and concentration of trace gases (NO, NO2, O3, SO2, CO, CO2). In addition to the continuous observations during the station motion, in Angarsk, Usol'e-Sibirskoe, Tulun, Nizhneudinsk, Taishet, Kansk, Krasnoyarsk, and Achinsk, we have carried measurements during stops at the city entry, near center, and at the exit. These observations were aimed to estimate the contribution of urban circulation to impurity accumulation on the city territory and to the change of thermodynamic regime. Such a contribution was found in all of the above-mentioned cities. Maximum of NO concentration is observed at crossroads of the main highways and decreases away from them. It should be noted that the NO distribution almost the same as the distribution of CO, which is also of "automobile engine" origin. In the center of cities where usually impurities are accumulated, concentration of SO2, NO2, CO, and aerosol number density as well are several times higher than in the city periphery. On the contrary, the ozone content in center is much lower. In most of the cases, the urban samples have 2-3 times more chemical elements than the background samples. The total concentrations of PAHs in aerosol matter of the cities varied from 20 to 30 ng/m3. PAH concentrations, as well as the percentage relation between them are determined by the place of aerosol sampling, i.e., by locations of pollution sources. Among the identified PAHs in the public green space and industrial zones of Angarsk, the predominating species are phenanthrene, pyrene, and fluoranthene, whose total amount reaches 80% of the mass of the detected PAHs. In summer, owing to more effective atmospheric ventilation, the effects of local circulation substantially weaken. As a result, a significant pollutant accumulation in the central parts of the cities may not always be detected.

  15. Microstructural stability after severe plastic deformation of AZ31 Magnesium

    NASA Astrophysics Data System (ADS)

    Young, J. P.; Askari, H.; Hovanski, Y.; Heiden, M. J.; Field, D. P.

    2014-08-01

    Friction stir processing (FSP) and equal channel angular pressing (ECAP) were used to modify the microstructure of twin roll cast (TRC) AZ31 magnesium. The influence of these processes on the microstructural properties of the material was investigated. It was found that both processes produced microstructures with an average grain size of less than 10 pm, suggesting that they have the potential for superplastic deformation. Heat treatments were performed on the TRC, ECAP and FSP materials to assess their microstructural stability. Both the ECAP and TRC material were found to be fairly stable, showing normal grain growth while the FSP material grew substantially at temperatures above 200°C. The activation energy of grain boundary motion of the TRC material was calculated to be 167 kJ/mol.

  16. Corrosion resistance of titanium ion implanted AZ91 magnesium alloy

    SciTech Connect

    Liu Chenglong; Xin Yunchang; Tian Xiubo; Zhao, J.; Chu, Paul K. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China) and Shenzhen Graduate School, Tsinghua University, Shenzhen 518055 (China); Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China) and State Key Laboratory of Welding Production Technology, School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 15001 (China); Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)

    2007-03-15

    Degradable metal alloys constitute a new class of materials for load-bearing biomedical implants. Owing to their good mechanical properties and biocompatibility, magnesium alloys are promising in degradable prosthetic implants. The objective of this study is to improve the corrosion behavior of surgical AZ91 magnesium alloy by titanium ion implantation. The surface characteristics of the ion implanted layer in the magnesium alloys are examined. The authors' results disclose that an intermixed layer is produced and the surface oxidized films are mainly composed of titanium oxide with a lesser amount of magnesium oxide. X-ray photoelectron spectroscopy reveals that the oxide has three layers. The outer layer which is 10 nm thick is mainly composed of MgO and TiO{sub 2} with some Mg(OH){sub 2}. The middle layer that is 50 nm thick comprises predominantly TiO{sub 2} and MgO with minor contributions from MgAl{sub 2}O{sub 4} and TiO. The third layer from the surface is rich in metallic Mg, Ti, Al, and Ti{sub 3}Al. The effects of Ti ion implantation on the corrosion resistance and electrochemical behavior of the magnesium alloys are investigated in simulated body fluids at 37{+-}1 deg. C using electrochemical impedance spectroscopy and open circuit potential techniques. Compared to the unimplanted AZ91 alloy, titanium ion implantation significantly shifts the open circuit potential (OCP) to a more positive potential and improves the corrosion resistance at OCP. This phenomenon can be ascribed to the more compact surface oxide film, enhanced reoxidation on the implanted surface, as well as the increased {beta}-Mg{sub 12}Al{sub 17} phase.

  17. Best Cities to Start and Grow a Company in Now

    NSDL National Science Digital Library

    Location. Location. Location. Inc. Magazine rates the best 50 US cities in which to start a business. After factoring in such elements as "available capital, a skilled labor pool, the enriching atmosphere created by universities, advanced transportation facilities, and good roads," Inc. has chosen Phoenix, AZ as its top choice. Along with the rankings, Inc. includes an article on how the right locations have benefited companies in a number of industries, a checklist of key issues to keep in mind when relocating a business, and a case study of Loudoun, VA. In italics at the bottom of the first page is a link to "the cities on the list"; this hidden gem offers links to 100 US cities's chambers of commerce and other business-related information.

  18. Influence of Aluminum Content on Grain Refinement and Strength of AZ31 Magnesium GTA Weld Metal

    SciTech Connect

    Babu, N. Kishore [Singapore Institute of Manufacturing Technology; Cross, Carl E. [Los Alamos National Laboratory

    2012-06-28

    The goal is to characterize the effect of Al content on AZ31 weld metal, the grain size and strength, and examine role of Al on grain refinement. The approach is to systematically vary the aluminum content of AZ31 weld metal, Measure average grain size in weld metal, and Measure cross-weld tensile properties and hardness. Conclusions are that: (1) increased Al content in AZ31 weld metal results in grain refinement Reason: higher undercooling during solidification; (2) weld metal grain refinement resulted in increased strength & hardness Reason: grain boundary strengthening; and (3) weld metal strength can be raised to wrought base metal levels.

  19. System Description for Tank 241-AZ-101 Waste Retrieval Data Acquisition System

    SciTech Connect

    ROMERO, S.G.

    2000-01-10

    Describes the hardware and software for the AZ-101 Mixer Pump Data Acquisition System. The purpose of the tank 241-AZ-101 retrieval system Data Acquisition System (DAS) is to provide monitoring and data acquisition of key parameters in order to confirm the effectiveness of the mixer pumps utilized for suspending solids in the tank. The suspension of solids in Tank 241-AZ-101 is necessary for pretreatment of the neutralized current acid waste (NCAW), and eventual disposal as glass via the Hanford Waste Vitrification Plant.

  20. Chemical speciation of PM2.5 and PM10 in south Phoenix, AZ, USA.

    PubMed

    Upadhyay, Nabin; Clements, Andrea; Fraser, Matthew; Herckes, Pierre

    2011-03-01

    Phoenix, AZ, experiences high particulate matter (PM) episodes, especially in the wintertime. The spatial variation of the PM concentrations and resulting differences in exposure is of particular concern. In this study, PM2.s (PM with aerodynamic diameter <2.5 microm) and PM10 (PM with aerodynamic diameter <10 microm) samples were collected simultaneously from the east and west sides of South Phoenix and at a control site in Tempe and analyzed for trace elements and bulk elemental and organic carbon. Measurements showed that although PM2.5 concentrations had similar trends in temporal scale across all sites, concentrations of PM10 did not. The difference in PM10 concentrations and fluctuation across the three sites suggest effects of a local soil source as evidenced by high concentrations of Al, Ca, and Fe in PM10. K and anthropogenic elements (e.g., Cu, Pb, and Zn) in PM2.5 samples on January 1 were strikingly high, suggesting the influence of New Year's fireworks. Concentrations of toxic elements (e.g., Pb) in the study presented here are not different from similar studies in other U.S. cities. Application of principal component analysis indicated two broad categories of emission sources--soil and combustion--together accounting for 80 and 90% of variance, respectively, in PM2.5 and PM10. The soil and combustion components explained approximately 60 and 30% of the variance in PM10, respectively, whereas combustion sources dominated PM2.5 (>50% variance). Many elements associated with anthropogenic sources were highly enriched, with enrichment factors in PM2.5 an order of magnitude higher than in PM10 relative to surface soil composition in the study area. PMID:21416757

  1. City of Anaheim City Manager's Office

    E-print Network

    de Lijser, Peter

    City of Anaheim City Manager's Office Volunteer Web Design Intern Job Description 1 The City of Anaheim seeks an intern to assist the City Manager's Office in graphic design with an emphasis on web design. This internship will give the intern valuable real-world experience in web design, as well

  2. 77 FR 20356 - Foreign-Trade Zone 277-Western Maricopa County, AZ; Application for Manufacturing Authority...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-04

    ...Authority; Suntech Arizona, Inc., (Solar Panel Manufacturing), Goodyear, AZ...manufacture of 275 and 290 watt solar panels for industrial use. Components...entry procedures that apply to solar panels (duty-free) for the...

  3. H2A.Z: a molecular rheostat for transcriptional control

    E-print Network

    Subramanian, Vidya

    The replacement of nucleosomal H2A with the histone variant H2A.Z is critical for regulating DNA-mediated processes across eukaryotes and for early development of multicellular organisms. How this variant performs these ...

  4. Operational Test Report for the 241-AZ-101 Ultrasonic Interface Level Analyzer

    SciTech Connect

    ANDREWS, J.E.

    2000-03-28

    This document comprises the Operational Test Report for the 241-AZ-101 Ultrasonic Interface Level Analyzer. The objective of the testing was to verify that all equipment and components functioned as designed following construction completion and turnover to operations.

  5. Draft Genome Sequence of Lysobacter capsici AZ78, a Bacterium Antagonistic to Plant-Pathogenic Oomycetes

    PubMed Central

    Sonego, Paolo; Engelen, Kristof; Pertot, Ilaria

    2014-01-01

    Lysobacter capsici AZ78, isolated from tobacco rhizosphere, effectively controls Phytophthora infestans and Plasmopara viticola on tomato and grapevine plants, respectively. We report the first draft genome sequence of the L. capsici species. PMID:24762937

  6. 78 FR 65370 - Notice of Inventory Completion: Pima County Office of the Medical Examiner, Tucson, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-31

    ...2013. ADDRESSES: Dr. Bruce Anderson, Forensic Anthropologist, PCOME, Tucson, AZ...County Medical Examiner's Office for forensic analysis. The Pinal County Medical Examiner...Medical Examiner for examination by a forensic anthropologist. Dr. Bruce...

  7. 75 FR 26711 - Plan Revision for Coconino National Forest; Coconino, Gila and Yavapai Counties, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-12

    ...AGRICULTURE Forest Service Plan Revision for Coconino National Forest; Coconino, Gila and Yavapai Counties, AZ AGENCY: Forest...the USDA Forest Service is preparing the Coconino National Forest's revised land management plan (Forest...

  8. 75 FR 49526 - Freescale Semiconductor, Inc., Technical Information Center, Tempe, AZ; Freescale Semiconductor...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-13

    ...TA-W-71,855A] Freescale Semiconductor, Inc., Technical Information Center, Tempe, AZ; Freescale Semiconductor, Inc., Technical Information...applicable to workers of Freescale Semiconductor, Inc., Technical...

  9. 76 FR 64041 - Proposed Amendment of Class E Airspace; Show Low, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-17

    ...Airport, Show Low, AZ. Controlled airspace is necessary to accommodate aircraft using Area Navigation (RNAV) Global Positioning System (GPS) standard instrument approach procedures at Show Low Regional Airport. The FAA is proposing this...

  10. 77 FR 2242 - Radio Broadcasting Services; Ehrenberg, First Mesa, Kachina Village, Wickenburg, and Williams, AZ...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-17

    ...RM-11518, RM-11519; DA 11- 2059] Radio Broadcasting Services; Ehrenberg, First Mesa, Kachina Village, Wickenburg, and Williams, AZ, and Needles, CA AGENCY: Federal Communications Commission. ACTION: Proposed rule;...

  11. 75 FR 11939 - DNS Electronics, Chandler, AZ; Notice of Termination of Investigation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-12

    ...Employment and Training Administration [TA-W-70,654] DNS Electronics, Chandler, AZ; Notice of Termination of Investigation...27, 2009, by three workers on behalf of workers of DNS Electronics, Chandler, Arizona. The petitioning group of workers...

  12. Foreseeing critical phosphorus cycle transitions in constructed wetlands: applied to the new Tres Rios arid-land constructed wetlands with the city of Phoenix

    E-print Network

    Hall, Sharon J.

    Foreseeing critical phosphorus cycle transitions in constructed wetlands: applied to the new Tres Rios arid-land constructed wetlands with the city of Phoenix E.Chapman1 and B.Warner2 1 School of Life Sciences, 2 School of Sustainability, Arizona State University,Tempe, AZ Abstract Constructed wetland

  13. Grain refinement of AZ31 and ZK60 Mg alloys — towards superplasticity studies

    Microsoft Academic Search

    A. Bussiba; A. Ben Artzy; A. Shtechman; S. Ifergan; M. Kupiec

    2001-01-01

    Low temperature superplastic (SP) behavior (mechanical and deformation mechanisms) of two commercial Mg-based alloys (AZ31 and ZK60) was characterized. The two alloys were tested in the as extruded condition with initial grain size of 15 ?m (AZ31) and fine (2 ?m) and coarse (25 ?m) grains mixed randomly for the ZK60. Strain rate was activated in the range 10?5–1 s?1

  14. Electrochemical characterization of non-chromate surface treatments on AZ80 magnesium

    Microsoft Academic Search

    Wen C. Say; Chien Chon Chen; Sheng-Jen Hsieh

    2008-01-01

    Surface treatments were applied to AZ80 magnesium alloy (8%Al–92%Mg) within non-chromate environments to develop its anti-corrosion characteristics. The non-chromate process involved chemical conversion using a phosphate and hydrofluoric acid (HF) coating, followed by anodizing. The chemical conversion generated good adhesion between the substrates and the anodic film. The anodizing process formed a 30 ?m-thick film on the surface of the AZ80.

  15. Microstructure, solute partitioning and material properties of gadolinium-doped magnesium alloy AZ91D

    Microsoft Academic Search

    Masaki Sumida; Sanghoon Jung; Toshimitsu Okane

    2009-01-01

    The effects of 10–25mass%Gd doping on the solidification microstructure, solute partitioning and material properties of the magnesium alloy AZ91D were investigated. AZ91D samples with 10–25mass%Gd were solidified by a furnace cooling technique from 700°C in an Ar flow. Microstructure observations showed that the Gd-doped alloys exhibit drastic structural changes to the ?Mg matrix with dispersed Al2Gd particles. SEM-EDS analysis indicated

  16. Fabrication of AZ31 alloy wire by continuous semisolid extrusion process

    Microsoft Academic Search

    Ren-guo GUAN; Zhan-yong ZHAO; Xiao-ping SUN; Hong-qian HUANG; Chun-guang DAI; Qiu-sheng ZHANG

    2010-01-01

    A novel technology of continuous semisolid extrusion Process (CSEP) was adopted to produce AZ31 alloy structural materials. Effects of technological conditions on the microstructures of AZ31 alloy during CSEP were studied. During the casting process, the non-uniform distribution of microstructures was found in the roll-shoe gap. Microstructure evolution from dendrite to rosette or spherical grains was observed during the casting

  17. Microstructure and mechanical behavior of die casting AZ91D-Fly ash cenosphere composites

    Microsoft Academic Search

    P. K. Rohatgi; A. Daoud; B. F. Schultz; T. Puri

    2009-01-01

    The feasibility of incorporating fly ash cenospheres in die cast magnesium alloy has been demonstrated. The effects of fly ash cenosphere additions on the microstructure and some of the salient physical and mechanical properties of magnesium alloy (AZ91D) metal matrix composites were investigated. The control AZ91D alloy and associated composites, containing 5, 10, and 15wt.% of fly ash cenospheres (added),

  18. Histone H2A.Z is essential for estrogen receptor signaling

    Microsoft Academic Search

    Nicolas Gevry; Sara Hardy; Pierre-Etienne Jacques; Liette Laflamme; Amy Svotelis; Franc xois Robert; Luc Gaudreau

    2009-01-01

    Incorporation of H2A.Z into the chromatin of inactive promoters has been shown to poise genes for their expression. Here we provide strong evidence that H2A.Z is incorporated into the promoter regions of estrogen receptor (ERa) target genes only upon gene induction, and that, in a cyclic pattern. Moreover, members of the human H2A.Z-depositing complex, p400, also follow the same gene

  19. Operational Test Report for the 241-AZ-101 Suspended Solids Profiler

    SciTech Connect

    STENKAMP, D.M.

    2000-04-03

    This document comprises the Operational Test Report for the 241-AZ-101 Suspended Solids Profiler. This document presents the results of Operational Testing of the 241-AZ-101 Suspended Solids Profiler (SSP). Testing of the SSP was performed in accordance with OTP-260-005, ''SUSPENDED SOLIDS PROFILER OPERATIONAL TEST PROCEDURE''. The objective of the testing was to verify that all equipment and components functioned as designed, following construction completion and turnover to operations.

  20. Kinetic City

    NSDL National Science Digital Library

    Developed by the American Association for the Advancement of Science, this website offers an assortment of science experiments, games, activities, and projects. In the Shape it Up game, students can learn about land formations and processes. Users can learn the basic interactions of mixing different chemicals in the Slush Rush link. Educators can find Leader packets and information on how to start a Kinetic City club. Besides the games educating users about topics in the physical sciences, the website also offers a variety of biology-related activities. After filling out the free sign-up form, the website saves individual's power points and results.

  1. Effect of microstructure on the zinc phosphate conversion coatings on magnesium alloy AZ91

    NASA Astrophysics Data System (ADS)

    Van Phuong, Nguyen; Moon, Sungmo; Chang, Doyon; Lee, Kyu Hwan

    2013-01-01

    The effect of the microstructure, particularly of ?-Mg17Al12 phase, on the formation and growth of zinc phosphate conversion coatings on magnesium alloy AZ91 (AZ91) was studied. The zinc phosphate coatings were formed on AZ91 with different microstructures produced by heat treatment. The effect of the microstructure on the zinc phosphate coatings were examined using optical microscope (OM), X-ray diffraction (XRD), coatings weight and etching weight balances, scanning electron microscopy (SEM) and salt immersion test. Results showed that as-cast AZ91 contained a high volume fraction of the ?-Mg17Al12 phase and it was dissolved into ?-Mg phase during heat treatment at 400 °C. The ?-phase became center for hydrogen evolution during phosphating reaction (cathodic sites). The decreased volume fraction of the ?-phase caused decreasing both coatings weight and etching weight of the phosphating process. However, it increased the crystal size of the coatings and improved corrosion resistance of AZ91 by immersing in 0.5 M NaCl solution. Results also showed that the structure of the zinc phosphate conversion on AZ91 consisted of two layers: an outer crystal Zn3(PO4)2·4H2O (hopeite) and an inner which was mainly composed of MgZn2(PO4)2 and Mg3(PO4)2. A mechanism for the formation of two layers of the coatings was also proposed in this study.

  2. Fine particulate chemical composition and light extinction at Meadview, AZ

    SciTech Connect

    Delbert J. Eatough; Wenxuan Cui; Jeffery Hull; Robert J. Farber [Brigham Young University, Provo, UT (United States). Department of Chemistry and Biochemistry

    2006-12-15

    The concentration of fine particulate nitrate, sulfate, and carbonaceous material was measured for 12-hr daynight samples using diffusion denuder samplers during the Project Measurement of Haze and Visibility Effects (MOHAVE) July to August 1992 Summer Intensive study at Meadview, AZ, just west of Grand Canyon National Park. Organic material was measured by several techniques. Only the diffusion denuder method measured the semivolatile organic material. Fine particulate sulfate and nitrate (using denuder technology) determined by various groups agreed. Based on the various collocated measurements obtained during the Project MOHAVE study, the precision of the major fine particulate species was {+-} 0.6 {mu}g/m{sup 3} organic material, {+-} 0.3 {mu}g/m{sup 3} ammonium sulfate, and {+-} 0.07 {mu}g/m{sup 3} ammonium nitrate. Fine particulate organic material was the principal particulate contributor to light extinction during the study period, with fine particulate sulfate as the second most important contributor. Particle light extinction was dominated by sulfate and organic material during periods of lowest light extinction. Combination of the extinction data and chemical mass balance analysis of sulfur oxides sources in the region indicate that the major anthropogenic contributors to light extinction were from the Los Angeles, CA, and Las Vegas, NV, urban areas. Mohave Power Project associated secondary sulfate was a negligible contributor to light extinction. 49 refs., 12 figs., 7 tabs.

  3. Learning Cities as Healthy Green Cities: Building Sustainable Opportunity Cities

    ERIC Educational Resources Information Center

    Kearns, Peter

    2012-01-01

    This paper discusses a new generation of learning cities we have called EcCoWell cities (Economy, Community, Well-being). The paper was prepared for the PASCAL International Exchanges (PIE) and is based on international experiences with PIE and developments in some cities. The paper argues for more holistic and integrated development so that…

  4. A-Z Index Search CSUF Home INSIDE

    E-print Network

    de Lijser, Peter

    Access. "This project is raising awareness that the wrong environment can be a precursor to disease, like and obesity and created the "Mobile Physical Activity Unit" -- a bus owned by Latino Health Access, where show that St. Joseph's neighborhood has the fewest parks or open spaces in the city. Page 1 of 3

  5. H2A.Z.2.2 is an alternatively spliced histone H2A.Z variant that causes severe nucleosome destabilization.

    PubMed

    Bönisch, Clemens; Schneider, Katrin; Pünzeler, Sebastian; Wiedemann, Sonja M; Bielmeier, Christina; Bocola, Marco; Eberl, H Christian; Kuegel, Wolfgang; Neumann, Jürgen; Kremmer, Elisabeth; Leonhardt, Heinrich; Mann, Matthias; Michaelis, Jens; Schermelleh, Lothar; Hake, Sandra B

    2012-07-01

    The histone variant H2A.Z has been implicated in many biological processes, such as gene regulation and genome stability. Here, we present the identification of H2A.Z.2.2 (Z.2.2), a novel alternatively spliced variant of histone H2A.Z and provide a comprehensive characterization of its expression and chromatin incorporation properties. Z.2.2 mRNA is found in all human cell lines and tissues with highest levels in brain. We show the proper splicing and in vivo existence of this variant protein in humans. Furthermore, we demonstrate the binding of Z.2.2 to H2A.Z-specific TIP60 and SRCAP chaperone complexes and its active replication-independent deposition into chromatin. Strikingly, various independent in vivo and in vitro analyses, such as biochemical fractionation, comparative FRAP studies of GFP-tagged H2A variants, size exclusion chromatography and single molecule FRET, in combination with in silico molecular dynamics simulations, consistently demonstrate that Z.2.2 causes major structural changes and significantly destabilizes nucleosomes. Analyses of deletion mutants and chimeric proteins pinpoint this property to its unique C-terminus. Our findings enrich the list of known human variants by an unusual protein belonging to the H2A.Z family that leads to the least stable nucleosome known to date. PMID:22467210

  6. Dynamic behavior and constitutive modeling of magnesium alloys AZ91D and AZ31B under high strain rate compressive loading

    NASA Astrophysics Data System (ADS)

    Xiao, Jing; Ahmad, Iram Raza; Shu, D. W.

    2014-03-01

    The dynamic stress-strain characteristics of magnesium alloys have not been sufficiently studied experimentally. Thus, the present work investigated compressive dynamic stress-strain characteristics of two representative magnesium alloys: AZ91D and AZ31B at high strain rates and elevated temperatures. In order to use the stress-strain characteristics in numerical simulations to predict the impact response of components, the stress-strain characteristics must be modeled. The most common approach is to use accepted constitutive laws. The results from the experimental study of the response of magnesium alloys AZ91D and AZ31B under dynamic compressive loading, at different strain rates and elevated temperatures are presented here. Johnson-Cook model was used to best fit the experimental data. The material parameters required by the model were obtained and the resultant stress-strain curves of the two alloys for each testing condition were plotted. It is found that the dynamic stress-strain relationship of both magnesium alloys are strain rate and temperature dependent and can be described reasonably well at high strain rates and room temperature by Johnson-Cook model except at very low strains. This might be due to the fact that the strain rate is not strictly constant in the early stage of deformation.

  7. A study on the relationships between corrosion properties and chemistry of thermally oxidised surface films formed on polished commercial magnesium alloys AZ31 and AZ61

    NASA Astrophysics Data System (ADS)

    Feliu, Sebastián; Samaniego, Alejandro; Barranco, Violeta; El-Hadad, A. A.; Llorente, Irene; Serra, Carmen; Galván, J. C.

    2014-03-01

    This paper studies the changes in chemical composition of the thin oxide surface films induced by heating in air at 200 °C for time intervals from 5 min to 60 min on the freshly polished commercial AZ31 and AZ61 alloys with a view to better understanding their protective properties. This thermal treatment resulted in the formation of layers enriched in metallic aluminium at the interface between the outer MgO surface films and the bulk material. A strong link was found between the degree of metallic Al enrichment in the subsurface layer (from 10 to 15 at.%) observed by XPS (X-ray photoelectron spectroscopy) in the AZ61 treated samples and the increase in protective properties observed by EIS (electrochemical impedance spectroscopy) in the immersion test in 0.6 M NaCl. Heating for 5-60 min in air at 200 °C seems to be an effective, easy to perform and inexpensive method for increasing the corrosion resistance of the AZ61 alloy by approximately two or three times.

  8. Superplastic Formability of AZ31 Magnesium Alloy Sheets Produced by Twin Roll Casting and Sequential Hot Rolling

    NASA Astrophysics Data System (ADS)

    Yu, Yandong; Lin, Kai; Jiang, Peng

    2013-07-01

    In this paper, superplastic tensile testing and gas bulging forming of AZ31 and AZ31 + Y + Sr magnesium alloys produced by twin roll casting (TRC) and sequential hot rolling were carried out. At 673 K, the superplastic formability of the TRC AZ31 magnesium alloy sheets added Y and Sr elements has improved significantly compared to the common TRC AZ31 sheets. Formations of cavities on the bulging part go through three stages of the nucleation, growth and aggregation, finally cavities merging lead to rupture at the top of the bulging part.

  9. Clean Cities Fact Sheet

    SciTech Connect

    Not Available

    2004-01-01

    This fact sheet explains the Clean Cities Program and provides contact information for all coalitions and regional offices. It answers key questions such as: What is the Clean Cities Program? What are alternative fuels? How does the Clean Cities Program work? What sort of assistance does Clean Cities offer? What has Clean Cities accomplished? What is Clean Cities International? and Where can I find more information?

  10. Dose rate analysis for Tank 101 AZ (Project W151)

    SciTech Connect

    Schwarz, R.A.; Hillesland, K.E.; Carter, L.L.

    1994-11-01

    This document describes the expected dose rates for modification to tank 101 AZ including modifications to the steam coil, mixer pump, and temperature probes. The thrust of the effort is to determine dose rates from: modification of a steam coil and caisson; the installation of mixer pumps; the installation of temperature probes; and estimates of dose rates that will be encountered while making these changes. Because the dose rates for all of these configurations depend upon the photon source within the supernate and sludge, comparisons were also made between measured dose rates within a drywell and the corresponding calculated dose rates. The calculational tool used is a Monte Carlo (MCNP{sub 2}) code since complicated three dimensional geometries are involved. A summary of the most important results of the entire study is given in Section 2. The basic calculational geometry model of the tank is discussed in Section 3, along with a tabulation of the photon sources that were used within the supernate and the sludge, and a discussion of uncertainties. The calculated dose rates around the steam coil and caisson before and after modification are discussed in Section 4. The configuration for the installation of the mixer pumps and the resulting dose rates are given in Section 5. The predicted changes in dose rates due to a possible dilution of the supernate source are given in Section 6. The calculational configuration used to model the installation of temperature probes and the resulting predicted dose rates are discussed in Section 7. Finally, comparisons of measured to calculated dose rates within a drywell are summarized in Section 8. Extended discussions of calculational models and Monte Carlo optimization techniques used are included in Appendix A.

  11. Fine particulate chemical composition and light extinction at Meadview, AZ.

    PubMed

    Eatough, Delbert J; Cui, Wenxuan; Hull, Jeffery; Farber, Robert J

    2006-12-01

    The concentration of fine particulate nitrate, sulfate, and carbonaceous material was measured for 12-hr day-night samples using diffusion denuder samplers during the Project Measurement of Haze and Visibility Effects (MOHAVE) July to August 1992 Summer Intensive study at Meadview, AZ, just west of Grand Canyon National Park. Organic material was measured by several techniques. Only the diffusion denuder method measured the semivolatile organic material. Fine particulate sulfate and nitrate (using denuder technology) determined by various groups agreed. Based on the various collocated measurements obtained during the Project MOHAVE study, the precision of the major fine particulate species was +/- 0.6 microg/m3 organic material, +/- 0.3 microg/m3 ammonium sulfate, and +/- 0.07 microg/m3 ammonium nitrate. Data were also available on fine particulate crustal material, fine and coarse particulate mass from the Interagency Monitoring of Protected Visual Environments sampling system, and relative humidity (RH), light absorption, particle scattering, and light extinction measurements from Project MOHAVE. An extinction budget was obtained using mass scattering coefficients estimated from particle size distribution data. Literature data were used to estimate the change in the mass scattering coefficients for the measured species as a function of RH and for the absorption of light by elemental carbon. Fine particulate organic material was the principal particulate contributor to light extinction during the study period, with fine particulate sulfate as the second most important contributor. During periods of highest light extinction, contributions from fine particulate organic material, sulfate, and light-absorbing carbon dominated the extinction of light by particles. Particle light extinction was dominated by sulfate and organic material during periods of lowest light extinction. Combination of the extinction data and chemical mass balance analysis of sulfur oxides sources in the region indicate that the major anthropogenic contributors to light extinction were from the Los Angeles, CA, and Las Vegas, NV, urban areas. Mohave Power Project associated secondary sulfate was a negligible contributor to light extinction. PMID:17195488

  12. Kinetics of recrystallization for twin-roll casting AZ31 magnesium alloy during homogenization

    NASA Astrophysics Data System (ADS)

    Zhao, Hu; Li, Pei-Jie; He, Liang-Ju

    2011-10-01

    The kinetics of recrystallization for twin-roll casting AZ31 magnesium alloy with different thicknesses during homogenization was analyzed. It is shown that fine grains are first formed at the boundaries of deformed bands in the twin-roll casting slab. The recrystallized grains with no strain are gradually substituted for the deformed microstructure of twin-roll casting AZ31 magnesium alloy. The incubation temperature and time for the recrystallization of a twin-roll casting AZ31 magnesium alloy strip with a thickness of 3 mm are lower and shorter than those of the 6-mm thick strip, respectively. The 3-mm thick twin-roll casting magnesium alloy has finer grains than the 6-mm thick strip. The activation energies of recrystallization for twin-roll casting AZ31 magnesium alloy slabs with the thickness of 3 and 6 mm are 88 and 69 kJ/mol, respectively. The kinetics curves of recrystallization for twin-roll casting AZ31 magnesium alloy were obtained.

  13. Tank 241-AZ-101 Mixer Pump Test Vapor Sampling and Analysis Plan

    SciTech Connect

    TEMPLETON, A.M.

    2000-04-10

    This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for vapor samples obtained during the operation of mixer pumps in tank 241-AZ-101. The primary purpose of the mixer pump test (MPT) is to demonstrate that the two 300 horsepower mixer pumps installed in tank 241-AZ-101 can mobilize the settled sludge so that it can be retrieved for treatment and vitrification. Sampling will be performed in accordance with Tank 241-AZ-101 Mixer Pump Test Data Quality Objective (Banning 1999) and Data Quality Objectives for Regulatory Requirements for Hazardous and Radioactive Air Emissions Sampling and Analysis (Mulkey 1999). The sampling will verify if current air emission estimates used in the permit application are correct and provide information for future air permit applications.

  14. City School Policy.

    ERIC Educational Resources Information Center

    City School Policy Committee, Portland, OR.

    This city school policy is intended to provide a definition of the relationship between Portland, Oregon, and the Portland Public Schools. The city's responsibility for education lies in city programs that affect the public schools. Four themes run through the publication, including rejuvenation and maintenance of city neighborhoods, best use of…

  15. City Stories Project

    NSDL National Science Digital Library

    The City Stories project is a network of city-based storytelling sites, tying real people in real cities all over the world together with a thread of personal stories. The first City Stories site was begun by Derek Powazek, and with offers from volunteers to maintain sites across the world, the City Stories network has expanded to several dozen cities, including Tumon (in Guam), Denver, San Diego, Chicago, and Seattle. The site also notes that City Stories will be expanding to over twenty new cities in the near future. Essentially, each City Stories site is a collection of short stories and thought pieces by local residents, sharing experiences and ideas through the site. Visitors to each site can also post their comments about each individual piece of writing and add their own stories. Finally, each site also contains links about their city for persons seeking to learn a bit more about the place.

  16. H2A.Z Acidic Patch Couples Chromatin Dynamics to Regulation of Gene Expression Programs during ESC Differentiation

    E-print Network

    Subramanian, Vidya

    The histone H2A variant H2A.Z is essential for embryonic development and for proper control of developmental gene expression programs in embryonic stem cells (ESCs). Divergent regions of amino acid sequence of H2A.Z likely ...

  17. Criticality safety of project W-151, 241-AZ-101 retrieval system process test

    SciTech Connect

    Vail, T.S., Westinghouse Hanford

    1996-07-16

    This Criticality Safety Evaluation Report (CSER) documents a review of the criticality safety implications of a process test to be performed in tank 241-AZ-101 (101-AZ). The process test will determine the effectiveness of the retrieval system for mobilization of solids and the practicality of the system for future use in the underground storage tanks at Hanford. The scope of the CSER extends only to the testing and operation of the mixer pumps and does not include the transfer of waste from the tank. Justification is provided that a nuclear criticality is extremely unlikely, if not impossible, in this tank.

  18. Great Zoom out of the Grand Canyon, AZ

    NSDL National Science Digital Library

    Greg Shirah

    2003-01-14

    Using data from different spacecraft and some powerful computer technology, visualizers at the Goddard Space Flight Center present you with a collection of American cities in a way you have never seen them before. Starting with our camera high above the Earth, we rush in towards the surface at what would be an impossible speed for any known vehicle. Passing though layers of atmosphere, the colors of our destinations shimmer with their own unique characteristics, and suddenly we find ourselves floating in virtual space just above the ground.

  19. CESIUM REMOVAL FROM TANKS 241-AN-103 & 241-SX-105 & 241-AZ-101 & 241AZ-102 COMPOSITE FOR TESTING IN BENCH SCALE STEAM REFORMER

    SciTech Connect

    DUNCAN JB; HUBER HJ

    2011-04-21

    This report documents the preparation of three actual Hanford tank waste samples for shipment to the Savannah River National Laboratory (SRNL). Two of the samples were dissolved saltcakes from tank 241-AN-103 (hereafter AN-103) and tank 241-SX-105 (hereafter SX-105); one sample was a supernate composite from tanks 241-AZ-101 and 241-AZ-102 (hereafter AZ-101/102). The preparation of the samples was executed following the test plans LAB-PLAN-10-00006, Test Plan for the Preparation of Samples from Hanford Tanks 241-SX-105, 241-AN-103, 241-AN-107, and LAB-PLN-l0-00014, Test Plan for the Preparation of a Composite Sample from Hanford Tanks 241-AZ-101 and 241-AZ-102 for Steam Reformer Testing at the Savannah River National Laboratory. All procedural steps were recorded in laboratory notebook HNF-N-274 3. Sample breakdown diagrams for AN-103 and SX-105 are presented in Appendix A. The tank samples were prepared in support of a series of treatability studies of the Fluidized Bed Steam Reforming (FBSR) process using a Bench-Scale Reformer (BSR) at SRNL. Tests with simulants have shown that the FBSR mineralized waste form is comparable to low-activity waste glass with respect to environmental durability (WSRC-STI-2008-00268, Mineralization of Radioactive Wastes by Fluidized Bed Steam Reforming (FBSR): Comparisons to Vitreous Waste Forms and Pertinent Durability Testing). However, a rigorous assessment requires long-term performance data from FBSR product formed from actual Hanford tank waste. Washington River Protection Solutions, LLC (WRPS) has initiated a Waste Form Qualification Program (WP-5.2.1-2010-001, Fluidized Bed Steam Reformer Low-level Waste Form Qualification) to gather the data required to demonstrate that an adequate FBSR mineralized waste form can be produced. The documentation of the selection process of the three tank samples has been separately reported in RPP-48824, Sample Selection Process for Bench-Scale Steam Reforming Treatability Studies Using Hanford Waste Samples.

  20. Effects of magnetic fields on the phosphate conversion coating of AZ91D magnesium alloy

    Microsoft Academic Search

    HuaLan Jin; XiangJie Yang; WenYi Peng; HongMin Guo

    2010-01-01

    An external high parallel magnetic fields (MF) was imposed on the barium phosphate process of AZ91D magnesium alloy. The influences of the permanent MF on the morphology, the phase composition and the corrosion resistance of the barium phosphate coatings were studied using scanning electron microscope, X-ray diffraction, salt spay test. The results show that the coatings with MF are more

  1. Microstructure evolution and deformation features of AZ31 Mg-alloy during creep

    Microsoft Academic Search

    Sugui Tian; Ling Wang; Keun Yong Sohn; Kyung Hyun Kim; Yongbo Xu; Zhuangqi Hu

    2006-01-01

    By means of the measurement of the creep curve and the observation of SEM and transmission electron microscope (TEM), an investigation has been made into the microstructure evolution and deformation features of AZ31 Mg-alloy during high temperature creep. Results show that the deformation features of the alloy in the primary stage of creep are that significant amount of dislocation slips

  2. January 2014 WIYN 3.5-meter Telescope at Kitt Peak near Tucson, AZ

    E-print Network

    Robeson, Scott M.

    January 2014 WIYN 3.5-meter Telescope at Kitt Peak near Tucson, AZ Undergraduate Studies Department studies of asteroid orbits in the solar system are still widely recognized. The historic Kirkwood courses and research programs include: the solar system (Sun, planets, asteroids, and comets), the life

  3. Localized climatic responses during the 11 July 1991 eclipse: Phoenix AZ

    Microsoft Academic Search

    A. J. Brazel; R. S. Cerveny; B. L. Trapido

    1993-01-01

    Measurements taken from a variety of land use environments in and around the Phoenix AZ metropolitan area were compared to determine the effects of various land use characteristics on the thermal response to a reduction of 68% in solar radiation during the solar eclipse of 11 July 1991. The results include: (a) The magnitude of the change in ambient air

  4. VizieR Online Data Catalog: AzTEC deep-field observations (Downes+, 2012)

    NASA Astrophysics Data System (ADS)

    Downes, T. P.; Welch, D.; Scott, K. S.; Austermann, J.; Wilson, G. W.; Yun, M. S.

    2013-02-01

    Instruments using arrays of many bolometers have become increasingly common in the past decade. The maps produced by such instruments typically include the filtering effects of the instrument as well as those from subsequent steps performed in the reduction of the data. Therefore interpretation of the maps is dependent upon accurately calculating the transfer function of the chosen reduction technique on the signal of interest. Many of these instruments use non-linear and iterative techniques to reduce their data because such methods can offer an improved signal-to-noise ratio over those that are purely linear, particularly for signals at scales comparable to that subtended by the array. We discuss a general approach for measuring the transfer function of principal component analysis on point sources that are small compared to the spatial extent seen by any single bolometer within the array. The results are applied to previously released AzTEC catalogues of the Cosmic Evolution Survey (COSMOS), Lockman Hole, Subaru XMM-Newton Deep Field, Great Observatories Origins Deep Survey (GOODS)-North and GOODS-South fields. Source flux density and noise estimates increase by roughly +10 per cent for fields observed while AzTEC was installed at the Atacama Submillimeter Telescope Experiment and +15-25 per cent while AzTEC was installed at the James Clerk Maxwell Telescope. Detection significance is, on average, unaffected by the revised technique. The revised photometry technique will be used in subsequent AzTEC releases. (5 data files).

  5. Validation of Airborne Visible-Infrared Imaging Spectrometer Data at Ray Mine, AZ

    NASA Technical Reports Server (NTRS)

    Lang, H.; Baloga, S.

    1999-01-01

    We validate 1997 Airborne Visible-Infrared Imaging Spectrometer (AVIRIS) reflectance spectra covering 0.4 meu - 2.4 meu from a stable, flat mineralogically characterized man-made target at Ray Mine, AZ, the site for an EPA/NASA assessment of the utility of remote sensing for monitoring acid drainage from an active open pit mine.

  6. Space Suited Crew Engineering Evaluation of the Proposed Array A-Z PSE Decoupled

    E-print Network

    Rathbun, Julie A.

    : : I Pt ·::., p.~ Space Suited Crew Engineering Evaluation of the Proposed Array A-Z PSE Decoupled TICN On January ZZ, 1971, the BxA Crew Engineering group performed a lG, space- suited handling Letter No. 9712-111). The purpose of the test was to determine if a space-suited deployment of the shroud

  7. Arabidopsis meiotic crossover hotspots overlap with H2A.Z nucleosomes at gene promoters

    PubMed Central

    Choi, Kyuha; Zhao, Xiaohui; Kelly, Krystyna A.; Venn, Oliver; Higgins, James D.; Yelina, Nataliya E.; Hardcastle, Thomas J.; Ziolkowski, Piotr A.; Copenhaver, Gregory P.; Franklin, F. Chris H.; McVean, Gil; Henderson, Ian R.

    2013-01-01

    PRDM9 directs human meiotic crossover hotspots to intergenic sequence motifs, whereas budding yeast hotspots overlap low nucleosome density regions in gene promoters. To investigate hotspots in plants, which lack PRDM9, we used coalescent analysis of Arabidopsis genetic variation. Crossovers increase towards gene promoters and terminators, and hotspots are associated with active chromatin modifications, including H2A.Z, histone H3K4me3, low nucleosome density and low DNA methylation. Hotspot-enriched A-rich and CTT-repeat DNA motifs occur upstream and downstream of transcriptional start respectively. Crossovers are asymmetric around promoters and highest over CTT-motifs and H2A.Z-nucleosomes. Pollen-typing, segregation and cytogenetic analysis show decreased crossovers in the arp6 H2A.Z deposition mutant, at multiple scales. During meiosis H2A.Z and DMC1/RAD51 recombinases form overlapping chromosomal foci. As arp6 reduces DMC1/RAD51 foci, H2A.Z may promote formation or processing of meiotic DNA double-strand breaks. We propose that gene chromatin ancestrally designates hotspots within eukaryotes and PRDM9 is a derived state within vertebrates. PMID:24056716

  8. Electrochemical Characteristics of AZ31 Magnesium Alloys with Microarc Oxidation Coating Alycia Berman1

    E-print Network

    Zhou, Yaoqi

    Electrochemical Characteristics of AZ31 Magnesium Alloys with Microarc Oxidation Coating Alycia arisen in recent years is the use of magnesium alloys due to their excellent mechanical properties. Magnesium alloys have many properties comparable to bone, including strength-to-weight ratio, density

  9. 78 FR 33703 - Safety Zone; Great Western Tube Float; Colorado River; Parker, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-05

    ...the entire width of the river, traffic would be allowed...includes the waters of the Colorado River between La Paz County Park...Casino and the width of the river in Parker, AZ. (b...local, state, and federal law enforcement vessels...

  10. June 2013AZ1596 Yield Monitoring technologY for irrigated

    E-print Network

    Sanderson, Mike

    June 2013AZ1596 Yield Monitoring technologY for irrigated cotton and grains in arizona: hardware COOPERATIVE EXTENSION Introduction The development of commercial-grade yield monitoring technology in the US, 14.6% of retail crop input dealers were engaged in sales and technical support for yield monitors

  11. Structural evaluation of thermocouple probes for 241-AZ-101 waste tank

    SciTech Connect

    Kanjilal, S.K.

    1994-12-06

    This document reports on the structural analysis of the thermocouple probe to be installed in 241-AZ-101 waste tank. The thermocouple probe is analyzed for normal pump mixing operation and potential earthquake induced loads required by the Hanford Site Design Criteria SDC-4.1.

  12. 75 FR 26098 - Safety Zone; Under Water Clean Up of Copper Canyon, Lake Havasu, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-11

    ...1625-AA00 Safety Zone; Under Water Clean Up of Copper Canyon, Lake Havasu, AZ AGENCY: Coast...the navigable waters of Lake Havasu in the Copper Canyon in support of the underwater cleanup of Copper Canyon. This temporary safety zone is...

  13. Changes in H2A.Z occupancy and DNA methylation during B-cell lymphomagenesis

    E-print Network

    Henikoff, Steven

    . Here, we ask whether a similar relationship exists in mammals, using a mouse B-cell lymphoma modelResearch Changes in H2A.Z occupancy and DNA methylation during B-cell lymphomagenesis Melissa L sites (TSSs) during MYC-induced transformation of pre-B cells and, subsequently, during lymphomagenesis

  14. Structural characterization of terrestrial microbial Mn oxides from Pinal Creek, AZ

    E-print Network

    rights reserved. 1. INTRODUCTION Manganese oxides, reactive high surface area particles, play innumerableStructural characterization of terrestrial microbial Mn oxides from Pinal Creek, AZ John R. Bargar October 2008; available online 25 November 2008 Abstract The microbial catalysis of Mn(II) oxidation

  15. Texture characterisation of hexagonal metals: Magnesium AZ91 alloy, welded by laser processing

    Microsoft Academic Search

    A. Kouadri; L. Barrallier

    2006-01-01

    Cooled and cast magnesium AZ91 alloy was welded using a CO2 laser. The changes in the microstructure were analysed by optical and scanning electron microscopy and X-ray diffraction. Modification of the anisotropic properties was evaluated by the characterization of the texture in the base metal, in the core of the welded zone and in the welded zone close to the

  16. 75 FR 5115 - Temporary Concession Contract for Lake Mead National Recreation Area, AZ/NV

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-01

    ...Lake Mead National Recreation Area, AZ/NV AGENCY: National Park...Lake Mead National Recreation Area...SUMMARY: Pursuant to 36 CFR 51.24, public notice is hereby...Lake Mead National Recreation Area, Arizona and Nevada for a...

  17. DNA Methylation, H2A.Z, and the Regulation of Constitutive Expression

    E-print Network

    to the histone variant H2A.Z. Studies in plants and animals have shown that the genome-wide distributions of H2A and TEs are methylated differently. Plants heavily methylate TEs in three sequence contexts (CG, CHG. ZILBERMAN Plant and Microbial Biology Department, University of California, Berkeley, California 94720

  18. Radioisotope inventory of T101AZ thermocouple tree from riser 13D

    SciTech Connect

    Kessler, S.F., Westinghouse Hanford

    1996-06-12

    The radionuclide inventory for the thermocouple tree removed from tank T101-AZ riser 13D was estimated using measured {sup 137}Cs activity. This activity was measured by detectors as the tree was removed from the tank. Other radionuclide activities were estimated using the results of tank samples.

  19. Microstructures and tensile properties of AZ31 magnesium alloy by continuous extrusion forming process

    Microsoft Academic Search

    Hui Zhang; Qiqi Yan; Luoxing Li

    2008-01-01

    The objective of this study is to investigate the possibility of continuous extrusion forming (Conform process) of AZ31 magnesium alloy. The results indicate that continuous extrusion forming can refine the structure, improve the degree of the structure homogeneity and change the crystal orientation of basal plane and hence enhance the ductility but decrease tensile strength at room temperature. The fracture

  20. ASES Proc. Solar 2010, Phoenix, AZ HIGH PERFORMANCE MSG SATELLITE MODEL FOR OPERATIONAL

    E-print Network

    Perez, Richard R.

    © ASES ­ Proc. Solar 2010, Phoenix, AZ HIGH PERFORMANCE MSG SATELLITE MODEL FOR OPERATIONAL SOLAR of global and direct irradiances from Meteosat Second Generation (MSG) satellite data covering Europe, Africa and Middle East. The full spatial and temporal resolutions of MSG data are used. The model

  1. Software Development Plan for the 241-AY and 241-AZ Tank Farm MICON automation system

    SciTech Connect

    Teats, M.C.

    1995-04-28

    Project W-030 will install a new tank ventilation system for the aging 241-AY and 241-AZ tank farm facilities. Controls for this system will be provided by a MICON distributed control system. This document defines the plan, deliverables, and schedule to develop software for the control system.

  2. Water Environment Federation. National TMDL Science and Policy Conference. Phoenix, AZ. November 13 16, 2002.

    E-print Network

    Pitt, Robert E.

    Water Environment Federation. National TMDL Science and Policy Conference. Phoenix, AZ. November 13 ­ 16, 2002. AVAILABILITY OF ATMOSPHERICALLY DEPOSITED MERCURY TO RUNOFF AND RECEIVING WATERS Mark C to receiving waters; such estimates are overly conservative, and do not reflect the complex nature of mercury

  3. Rapid coating of AZ31 magnesium alloy with calcium deficient hydroxyapatite using microwave energy.

    PubMed

    Ren, Yufu; Zhou, Huan; Nabiyouni, Maryam; Bhaduri, Sarit B

    2015-04-01

    Due to their unique biodegradability, magnesium alloys have been recognized as suitable metallic implant materials for degradable bone implants and bioresorbable cardiovascular stents. However, the extremely high degradation rate of magnesium alloys in physiological environment has restricted its practical application. This paper reports the use of a novel microwave assisted coating technology to improve the in vitro corrosion resistance and biocompatibility of Mg alloy AZ31. Results indicate that a dense calcium deficient hydroxyapatite (CDHA) layer was uniformly coated on a AZ31 substrate in less than 10min. Weight loss measurement and SEM were used to evaluate corrosion behaviors in vitro of coated samples and of non-coated samples. It was seen that CDHA coatings remarkably reduced the mass loss of AZ31 alloy after 7days of immersion in SBF. In addition, the prompt precipitation of bone-like apatite layer on the sample surface during immersion demonstrated a good bioactivity of the CDHA coatings. Proliferation of osteoblast cells was promoted in 5days of incubation, which indicated that the CDHA coatings could improve the cytocompatibility of the AZ31 alloy. All the results suggest that the CDHA coatings, serving as a protective layer, can enhance the corrosion resistance and biological response of magnesium alloys. Furthermore, this microwave assisted coating technology could be a promising method for rapid surface modification of biomedical materials. PMID:25686961

  4. Waste Toolkit A-Z Food waste (recycling on-site)

    E-print Network

    Melham, Tom

    Waste Toolkit A-Z Food waste (recycling on-site) How can I recycle food waste on-site? Recycling food waste on-site is a new concept as the University typically has its waste collected and taken away to be recycled. While this is better than sending waste to landfill, there is a more sustainable way to recycle

  5. 2 CITY COUNCIL CITY OF NEW YORK

    E-print Network

    Columbia University

    Working Waterfront Association New York/New Jersey Baykeeper 24 25 #12;3 1 2 A P P E A R A N C E 13 Nellie Tsipoura 14 Research Associate Natural Resources Defense Council 15 Ronald Bourque 161 2 CITY COUNCIL 3 CITY OF NEW YORK 4 -------------------------------x 5 THE TRANSCRIPT

  6. Jerusalem: City of Dreams, City of Sorrows

    ERIC Educational Resources Information Center

    Ricks, Thomas

    2011-01-01

    Jerusalem is more than an intriguing global historical city; it is a classroom for liberal learning and international understanding. It had never been a city of one language, one religion and one culture. Looking at the origins of Jerusalem's name indicates its international and multicultural nature. While Israelis designate Jerusalem as their…

  7. Kolibri. Az ELTE knyvtrosainak hrlevele. Kiadja az ELTE Egyetemi Knyvtr Hlzati s mdszertani osztlya. Fiszerkeszti: Klczi Katalin fiigazgat-helyettes. Szerkeszti: Fbin Edit (fabian.edit@lib.elte.hu)

    E-print Network

    Müller, Viktor

    : Kálóczi Katalin fiigazgató-helyettes. Szerkeszti: Fábián Edit (fabian.edit@lib.elte.hu) 2 A Minerva-EBSCO és SAGE kiadó közös információs napja 2009. június 23. (kedd) a Minerva-EBSCO és a Sage kiadó közös A rendezvényen az EBSCO új ajánlatait fogják bemutatni szakembereik az alábbi témában: ,,Integrált megoldások az

  8. Characterization of the first core sample of neutralized current acid waste from double-shell tank 101-AZ

    SciTech Connect

    Peterson, M E; Scheele, R D; Tingey, J M

    1989-09-01

    In FY 1989, Westinghouse Hanford Company (WHC) successfully obtained four core samples (totaling seven segments) of neutralized current acid waste (NCAW) from double-shell tanks (DSTs) 101-AZ and 102-AZ. A segment was a 19-in.-long and 1-in.-diameter cylindrical sample of waste. A core sample consisted of enough 19-in.-long segments to obtain the waste of interest. Three core samples were obtained from DST 101-AZ and one core sample from DST 102-AZ. Two DST 101-AZ core samples consisted of two segments per core, and the third core sample consisted of only one segment. The third core consisted of the solids from the bottom of the tank and was used to determine the relative abrasiveness of this NCAW. The DST 102-AZ core sample consisted of two segments. The core samples were transported to the Pacific Northwest Laboratory (PNL), where the waste was extruded from its sampler and extensively characterized. A characterization plan was followed that simulated the processing of the NCAW samples through retrieval, pretreatment and vitrification process steps. Physical, rheological, chemical and radiochemical properties were measured throughout the process steps. The characterization of the first core sample from DST 101-AZ was completed, and the results are provided in this report. The results for the other core characterizations will be reported in future reports. 3 refs., 13 figs., 10 tabs.

  9. What Is Clean Cities?

    SciTech Connect

    Not Available

    2007-08-01

    This Clean Cities Program fact sheet describes the purpose and scope of this DOE program. Clean Cities facilitates the use of alternative and advanced fuels and vehicles to displace petroleum in the transportation sector.

  10. "City of Bits"

    NSDL National Science Digital Library

    "City of Bits" is the MIT Press's first WWW book, "City of Bits: Space, Place, and the Infobahn," is about a new type of "city," constructed of interconnected virtual spaces on the network. The online version functions as a companion to its printed counterpart. Reader comments or queries are embedded in the text to become part of an on-going dialogue in which author and reader will interact. ("City of Bits," MIT Press, 1995) [From Edupage 6/22/95

  11. Smart cities in Europe

    Microsoft Academic Search

    A. Caragliu; C. Del Bo; P. Nijkamp

    2009-01-01

    Urban performance currently depends not only on the city’s endowment of hard infrastructure (‘physical capital’), but also, and increasingly so, on the availability and quality of knowledge communication and social infrastructure (‘human and social capital’). The latter form of capital is decisive for urban competitiveness. Against this background, the concept of the ‘smart city’ has recently been introduced as a

  12. Strategies to Reduce the Harmful Effects of Extreme Heat Events: A Four-City Study

    PubMed Central

    White-Newsome, Jalonne L.; McCormick, Sabrina; Sampson, Natalie; Buxton, Miatta A.; O’Neill, Marie S.; Gronlund, Carina J.; Catalano, Linda; Conlon, Kathryn C.; Parker, Edith A.

    2014-01-01

    Extreme heat events (EHEs) are becoming more intense, more frequent and longer lasting in the 21st century. These events can disproportionately impact the health of low-income, minority, and urban populations. To better understand heat-related intervention strategies used by four U.S. cities, we conducted 73 semi-structured interviews with government and non-governmental organization leaders representing public health, general social services, emergency management, meteorology, and the environmental planning sectors in Detroit, MI; New York City, NY; Philadelphia, PA and Phoenix, AZ—cities selected for their diverse demographics, climates, and climate adaptation strategies. We identified activities these leaders used to reduce the harmful effects of heat for residents in their city, as well as the obstacles they faced and the approaches they used to evaluate these efforts. Local leaders provided a description of how local context (e.g., climate, governance and city structure) impacted heat preparedness. Despite the differences among study cities, political will and resource access were critical to driving heat-health related programming. Upon completion of our interviews, we convened leaders in each city to discuss these findings and their ongoing efforts through day-long workshops. Our findings and the recommendations that emerged from these workshops could inform other local or national efforts towards preventing heat-related morbidity and mortality. PMID:24531122

  13. AZ-101 Mixer Pump Demonstration Data Acquisition System and Gamma Cart Data Acquisition Control System Software Configuration Management Plan

    SciTech Connect

    WHITE, D.A.

    1999-12-29

    This Software Configuration Management Plan (SCMP) provides the instructions for change control of the AZ1101 Mixer Pump Demonstration Data Acquisition System (DAS) and the Sludge Mobilization Cart (Gamma Cart) Data Acquisition and Control System (DACS).

  14. 78 FR 53477 - Notice of Relocation of the Bureau of Land Management's San Pedro Project Office in Sierra Vista, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-29

    ...of the Bureau of Land Management's San Pedro Project Office in Sierra Vista, AZ AGENCY: Bureau of Land Management, Interior. ACTION...of the Bureau of Land Management's (BLM) San Pedro Project Office (SPPO),...

  15. H2A.Z landscapes and dual modifications in pluripotent and multipotent stem cells underlie complex genome regulatory functions

    E-print Network

    Ku, Manching

    Background: The histone variant H2A.Z has been implicated in nucleosome exchange, transcriptional activation and Polycomb repression. However, the relationships among these seemingly disparate functions remain obscure.

  16. H2A.Z landscapes and dual modifications in pluripotent and multipotent stem cells underlie complex genome regulatory functions

    E-print Network

    Ku, Manching

    Abstract Background The histone variant H2A.Z has been implicated in nucleosome exchange, transcriptional activation and Polycomb repression. However, the relationships among these seemingly disparate functions remain ...

  17. Victory City: The City of the Future

    NSDL National Science Digital Library

    For the past 40-odd years, Orville Simpson II has been pursuing a dream, his vision of a city of the future, a Victory City based on reason and efficiency. Victory Cities would be entirely self-contained under one roof, ideally consisting of seven linked buildings -- each 102 stories -- containing residences, offices, industry, and retail space. Although the idea of snap-out modular walls, furniture bolted to the floors, and no kitchens (residents will be transported to the cafeterias by Ferris wheels) does not appeal to everyone, Simpson must be given credit for the depth and breadth of his vision. Users reading the Residents Guide will find that few details have been overlooked. Simpson addresses issues such as the money and food systems, education, postal service, transportation, security, recreation, pets, healthcare, ecological issues, and so on. Users can view numerous floor plans and conceptual drawings in the Victory City tour, review his arguments for the city in the Purpose/Benefits section, and read a collection of newspaper and magazine features on the man and his city in the Media Coverage section. Simpson is, by the way, still seeking investors.

  18. Effects of Er on the microstructure and properties of AZ31 magnesium alloy prepared via the EMS process

    Microsoft Academic Search

    Yutao Ma; Xingguo Zhang; Hongbin Liu; Linggang Meng

    2010-01-01

    The effects of small amounts of the rare-earth element erbium on the microstructure and the mechanical properties of AZ31\\u000a magnesium alloy via the electromagnetic stirring (EMS) process have been studied. It has been shown that AZ31-Er alloys are\\u000a mainly composed of ?-Mg solid solution and ?-Mg17Al12 phases. When the Er content reaches 0.12 wt.%, the characteristic peaks of Al2Er can

  19. Surface characterization and cytocompatibility evaluation of silanized magnesium alloy AZ91 for biomedical applications

    NASA Astrophysics Data System (ADS)

    Witecka, Agnieszka; Yamamoto, Akiko; Dybiec, Henryk; Swieszkowski, Wojciech

    2012-12-01

    Mg alloys with high Al contents have superior corrosion resistance in aqueous environments, but poor cytocompatibility compared to that of pure Mg. We have silanized the cast AZ91 alloy to improve its cytocompatibility using five different silanes: ethyltriethoxysilane (S1), 3-aminopropyltriethoxysilane (S2), 3-isocyanatopyltriethoxysilane (S3), phenyltriethoxysilane (S4) and octadecyltriethoxysilane (S5). The surface hydrophilicity/hydrophobicity was evaluated by water contact angle measurements. X-ray photoelectron analysis was performed to investigate the changes in surface states and chemical composition. All silane reagents increased adsorption of the albumin to the modified surface. In vitro cytocompatibility evaluation revealed that silanization improved cell growth on AZ91 modified by silane S1. Measurement of the concentration of Mg2+ ions released during the cell culture indicated that silanization does not affect substrate degradation.

  20. Study on the solidification microstructure in AZ91D Mg alloy after laser surface melting

    NASA Astrophysics Data System (ADS)

    Guan, Y. C.; Zhou, W.; Li, Z. L.; Zheng, H. Y.

    2009-07-01

    Laser surface melting (LSM) is known to enhance the wear and corrosion resistance of Mg alloys, but its effect on microstructural evolution of Mg alloys is not well understood. An effort has been made to study the effect of rapid solidification following LSM on the microstructural evolution of AZ91D Mg alloy. The results of X-ray diffractometry, scanning electron microscopy, transmission electron microscopy and energy-dispersive X-ray spectroscopy indicated that the solidification microstructure in the laser-melted zone was mainly cellular/dendrite structure of primarily ?-Mg phase and continuous network of ?-Mg 17Al 12 phase. Numerical prediction of the laser-melted zone suggested that cooling rates increased strongly from the bottom to the top surface in the irradiated regions. An attempt has been made to correlate dendrite cell sizes of the solidification microstructure with the cooling rates in the laser-treated AZ91D Mg alloy.

  1. Corrosion Behavior of AZ91D Magnesium Alloy in Three Different Physiological Environments

    NASA Astrophysics Data System (ADS)

    Zhou, Juncen; Li, Qing; Zhang, Haixiao; Chen, Funan

    2014-01-01

    Magnesium alloys have been considered as promising biomedical materials and were studied in different physiological environments. In this work, corrosion behavior of AZ91D magnesium alloy in artificial saliva, simulated body fluid (SBF), and 3.5 wt.% NaCl solution was investigated using electrochemical techniques and a short-term immersion test. In contrast with other physiological environments, the amount of aggressive ions in artificial saliva is small. In addition, a protective film is formed on the surface of samples in artificial saliva. Experimental results suggest that corrosion resistance of AZ91D magnesium alloy in artificial saliva is better than that in c-SBF and 3.5 wt.% NaCl solution.

  2. Diffusion and solubility of Au implanted into the AZ1350 photoresist

    NASA Astrophysics Data System (ADS)

    Soares, M. R. F.; Kaschny, J. R. A.; dos Santos, J. H. R.; Amaral, L.; Behar, M.; Fink, D.

    2000-05-01

    In the present paper we report diffusion and solubility results for Au into the photoresist AZ1350. Au was implanted into AZ1350 films at very low energy (E=20 keV) and fluences (?=1012 and 5×1012 Au/cm2). In this way the radiation damage introduced by the implantation process was minimized and cluster formation was avoided. Annealing was performed in the 150-300°C temperature range and the as implanted and thermal treated samples were analyzed using the Rutherford backscattering (RBS) technique. For the lowest implantation fluence the results have shown a regular atomic diffusion process characterized by an activation energy of Ea=640 meV. Instead, for ?=5×1012 Au/cm2 the diffusional mechanism has revealed the effects of the radiation damage. In addition solubility measurements indicate that the solubility limit at 250°C is of the order 0.3 at.%.

  3. Gyakorl feladatsor A3 vizsga utols hrom feladathoz 1. Hatrozza meg az RND3

    E-print Network

    Sándor, Csaba

    Gyakorló feladatsor A3 vizsga utolsó három feladatához 1. Határozza meg az RND3 eloszlásfüggvényét, várható értékét, szórását! 2. Határozza meg az 1 10 RND eloszlásfüggvényét, várható értékét, szórását! 3) Határozza meg a max{RND1, . . . , RND10} eloszlásfüggvényét! (b) Határozza meg a min{RND1, . . . , RND10

  4. Comparison of simulants to actual neutralized current acid waste: Process and product testing of three NCAW core samples from Tanks 101-AZ and 102-AZ

    SciTech Connect

    Morrey, E.V.; Tingey, J.M.

    1996-04-01

    A vitrification plant is planned to process the high-level waste (HLW) solids from Hanford Site tanks into canistered glass logs for disposal in a national repository. Programs have been established within the Pacific Northwest Laboratory Vitrification Technology Development (PVTD) Project to test and model simulated waste to support design, feed processability, operations, permitting, safety, and waste-form qualification. Parallel testing with actual radioactive waste is being performed on a laboratory-scale to confirm the validity of using simulants and glass property models developed from simulants. Laboratory-scale testing has been completed on three radioactive core samples from tanks 101-AZ and 102-AZ containing neutralized current acid waste (NCAW), which is one of the first waste types to be processed in the high-level waste vitrification plant under a privatization scenario. Properties of the radioactive waste measured during process and product testing were compared to simulant properties and model predictions to confirm the validity of simulant and glass property models work. This report includes results from the three NCAW core samples, comparable results from slurry and glass simulants, and comparisons to glass property model predictions.

  5. Test plan: Laboratory-scale testing of the first core sample from Tank 102-AZ

    SciTech Connect

    Morrey, E.V.

    1996-03-01

    The overall objectives of the Radioactive Process/Product Laboratory Testing (RPPLT), WBS 1.2.2.05.05, are to confirm that simulated HWVP feed and glass are representative of actual radioactive HWVP feed and glass and to provide radioactive leaching and glass composition data to WFQ. This study will provide data from one additional NCAW core sample (102-AZ Core 1) for these purposes.

  6. Influence of anisotropy of the magnesium alloy AZ31 sheets on warm negative incremental forming

    Microsoft Academic Search

    Qinglai Zhang; Hailing Guo; Fugui Xiao; Lin Gao; A. B. Bondarev; Weidong Han

    2009-01-01

    Single point incremental forming of the magnesium alloy AZ31 sheets, which were fabricated by hot extrusion, slab+hot\\/cold rolling, strip-casting rolling and cross-rolling, respectively, was investigated at elevated temperatures. The results show that the anisotropy of the sheets fabricated by casting slab+hot\\/cold rolling and cross-rolling is not remarkable, and the formability is improved significantly. The circular, square and rotary cone parts

  7. Identification of an advanced constitutive model of Magnesium alloy AZ31B

    Microsoft Academic Search

    Z. G. Liu; E. Massoni

    2011-01-01

    The main aim of this paper is to study the flow behavior of the AZ31B magnesium alloy by means of tensile tests performed in extended ranges of temperature and strain rates. The flow stress-strain curves analyzed by power law type constitutive equation [1] can only fit well with experimental curves at the work-hardening stage. A new mathematical model is studied

  8. Measurement and Analysis of the Biaxial Loading and Unloading Behavior of AZ31 Mg Alloy Sheet

    Microsoft Academic Search

    Mohammad Omar Andar; Dirk Steglich; Toshihiko Kuwabara

    2011-01-01

    A commercial AZ31 magnesium alloy sheet has been tested under proportional biaxial tensile loading using cruciform specimens. In order to quantitatively determine the elastic-plastic deformation behavior of the test material, the contours of plastic work and the directions of plastic strain rates were measured over a range of equivalent plastic strain, 0.001 <=epsilo0p<=0.008. The measured work contours and the directions

  9. Influence of annealing on the microstructure of commercial Mg alloy AZ31 after mechanical forming

    Microsoft Academic Search

    A. Jäger; P. Luká?; V. Gärtnerová; J. Haloda; M. Dopita

    2006-01-01

    The microstructure of commercial rolled magnesium alloy AZ31B (nominal composition Mg–3Al–0.9Zn–0.15Mn in wt.%) was investigated with the help of light microscopy, electron backscatter diffraction (EBSD) and X-ray diffraction technique after annealing in the temperature range from room temperature (RT) to 400°C. Tensile tests at RT were performed to show the influence of the microstructure on mechanical properties. Static recrystallization (SRX)

  10. AzTEC 1.1 mm OBSERVATIONS OF THE MBM12 MOLECULAR CLOUD

    SciTech Connect

    Kim, M. J.; Kim, S.; Youn, S.; Kang, Y.-W. [Department of Astronomy and Space Science, Sejong University, KwangJin-gu, KunJa-dong 98, Seoul 143-747 (Korea, Republic of); Yun, M. S.; Wilson, G. W. [Department of Astronomy, University of Massachusetts, 710 North Pleasant St., Amherst, MA 01003 (United States); Aretxaga, I.; Hughes, D. H.; Humphrey, A. [Instituto Nacional de Astrofisca, Optica y Electronica, Tonantzintla, Puebla (Mexico); Williams, J. P. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Austermann, J. E. [Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, Colorado 80309 (United States); Perera, T. A. [Department of Physics, Illinois Wesleyan University, Bloomington, IL 61701 (United States); Mauskopf, P. D. [School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA (United Kingdom); Magnani, L., E-mail: sek@sejong.ac.kr [Department of Physics and Astronomy, The University of Georgia, Athens, GA 30602-2451 (United States)

    2012-02-10

    We present 1.1 mm observations of the dust continuum emission from the MBM12 high-latitude molecular cloud observed with the Astronomical Thermal Emission Camera (AzTEC) mounted on the James Clerk Maxwell Telescope on Mauna Kea, Hawaii. We surveyed 6.34 deg{sup 2} centered on MBM12, making this the largest area that has ever been surveyed in this region with submillimeter and millimeter telescopes. Eight secure individual sources were detected with a signal-to-noise ratio of over 4.4. These eight AzTEC sources can be considered to be real astronomical objects compared to the other candidates based on calculations of the false detection rate. The distribution of the detected 1.1 mm sources or compact 1.1 mm peaks is spatially anti-correlated with that of the 100 {mu}m emission and the {sup 12}CO emission. We detected the 1.1 mm dust continuum emitting sources associated with two classical T Tauri stars, LkH{alpha}262 and LkH{alpha}264. Observations of spectral energy distributions (SEDs) indicate that LkH{alpha}262 is likely to be Class II (pre-main-sequence star), but there are also indications that it could be a late Class I (protostar). A flared disk and a bipolar cavity in the models of Class I sources lead to more complicated SEDs. From the present AzTEC observations of the MBM12 region, it appears that other sources detected with AzTEC are likely to be extragalactic and located behind MBM12. Some of these have radio counterparts and their star formation rates are derived from a fit of the SEDs to the photometric evolution of galaxies in which the effects of a dusty interstellar medium have been included.

  11. Investigation of the gas-jet ejector in KamAZ trucks

    Microsoft Academic Search

    L. Y. Shkret; A. I. Berezea; A. N. Lobkov

    1984-01-01

    This article considers the possibility of using gas-jet vacuum pumps in tank trucks for transporting liquids (water) at drilling sites. The discharge system of the KamAZ trucks can be reliably sealed by an engine brake, an important prerequisite of reliable operation of a gas-jet ejector that is switched on when the tank is being filled. The ejector consists of a

  12. Evaluation of microstructural effects on corrosion behaviour of AZ91D magnesium alloy

    Microsoft Academic Search

    Rajan Ambat; Naing Naing Aung; W Zhou

    2000-01-01

    The effect of microconstituents on the corrosion and electrochemical behaviour of AZ91D alloy prepared by die-casting and ingot casting route has been investigated in 3.5% NaCl solution at pH 7.25. The experimental techniques used include constant immersion technique, in-situ corrosion monitoring, and potentiodynamic polarisation experiments. Surface examination and analytical studies were carried out using optical and scanning electron microscopy, EDX

  13. Superplastic deformation behavior of hot-rolled AZ31 magnesium alloy sheet at elevated temperatures

    Microsoft Academic Search

    Zhang Kaifeng; Yin Deliang; Wang Guofeng; Han Wenbo

    2006-01-01

    Uniaxial tensile tests were carried out in the temperature range of 250–450°C and the strain rate range of 0.7×10?3–1.4×10?1 s?1 to evaluate the superplasticity of AZ31 Mg alloy. The threshold stress which characterizes the difficulty for grain boundary\\u000a sliding was calculated at various temperatures. The surface relieves of superplastically deformed specimens were observed\\u000a by using a scanning electronic microscope (SEM).

  14. Mechanical properties and microstructure of gas tungsten arc welded magnesium AZ91D plates

    Microsoft Academic Search

    A. Munitz; C. Cotler; A. Stern; G. Kohn

    2001-01-01

    Gas tungsten arc (GTA) welds were performed on 4-mm thick plates, machined from as-cast magnesium AZ91D ingots. The microstructure and defect formation was investigated by optical and scanning electron microscopy. Mechanical properties were determined by standard tensile tests on small-scale specimens. A wide heat affected zone (HAZ) (>3 mm) was created adjacent to the fusion line that consisted of two

  15. Chemical Conversion Coating on AZ91D and its Corrosion Resistance

    Microsoft Academic Search

    En-Hou Han; Wanqiu Zhou; Dayong Shan; Wei Ke

    The black chromium-free phosphate chemical conversion coating was obtained on die casting AZ91D magnesium alloy. The film formation kinetics and corrosion resistance of the conversion coating in 3.5% NaCl solution were analyzed by electrochemical methods. The corrosion rate was evaluated by immersion test. And the chemical compositions were analyzed by XRD and surface analysis system. The passivation curve was obtained

  16. Preparation of AZ31 magnesium alloy strips using vertical twin-roll caster

    Microsoft Academic Search

    Guang-shan WANG; Hong-shuang DI; Feng HUANG

    2010-01-01

    A newly developed technology for manufacturing magnesium alloy strip, vertical twin-roll strip casting, has been described. This manufacturing process is easy to be facilitated in an economical way to manufacture wrought magnesium alloy strips. As an example, AZ31 magnesium alloy was used to investigate the appropriate manufacturing conditions for vertical twin-roll strip casting by varying the temperatures of the molten

  17. Folytonos valoszinusegi valtozok Az X egy folytonos valoszinusegi valtozo, ha a lehetseges

    E-print Network

    Sándor, Csaba

    (X) = a + b 2 , D(X) = b - a 12 #12;P´eld´ak: 1. Legyen RND a [0, 1] intervallumban egyenletes eloszl´as´u v.v. Ekkor f(x) = 1, ha 0 1 E(RND) = 1 2 , D(RND) = 1 12 2. Hogyan kaphatun a [2, 5] intervallumon egyenletes eloszl´as´u v.v.-t az RND

  18. Mutations in Non-Acid Patch Residues Disrupt H2A.Z’s Association with Chromatin through Multiple Mechanisms

    PubMed Central

    Wood, Thomas J.; Thistlethwaite, Angela; Harris, Michael R.; Lovell, Simon C.; Millar, Catherine B.

    2013-01-01

    The incorporation of histone variants into nucleosomes is a critical mechanism for regulating essential DNA-templated processes and for establishing distinct chromatin architectures with specialised functions. H2A.Z is an evolutionarily conserved H2A variant that has diverse roles in transcriptional regulation, heterochromatin boundary definition, chromosome stability and DNA repair. The H2A.Z C-terminus diverges in sequence from canonical H2A and imparts unique functions to H2A.Z in the yeast S. cerevisiae. Although mediated in part through the acid patch-containing M6 region, many molecular determinants of this divergent structure-function relationship remain unclear. Here, by using an unbiased random mutagenesis screen of H2A.Z alleles, we identify point mutations in the C-terminus outside of the M6 region that disrupt the normal function of H2A.Z in response to cytotoxic stress. These functional defects correlate with reduced chromatin association, which we attribute to reduced physical stability within chromatin, but also to altered interactions with the SWR and INO80 chromatin remodeling complexes. Together with experimental data, computational modelling of these residue changes in the context of protein structure suggests the importance of C-terminal domain integrity and configuration for maintaining the level of H2A.Z in nucleosomes. PMID:24098487

  19. A histone acetylation switch regulates H2A.Z deposition by the SWR-C remodeling enzyme.

    PubMed

    Watanabe, Shinya; Radman-Livaja, Marta; Rando, Oliver J; Peterson, Craig L

    2013-04-12

    The histone variant H2A.Z plays key roles in gene expression, DNA repair, and centromere function. H2A.Z deposition is controlled by SWR-C chromatin remodeling enzymes that catalyze the nucleosomal exchange of canonical H2A with H2A.Z. Here we report that acetylation of histone H3 on lysine 56 (H3-K56Ac) alters the substrate specificity of SWR-C, leading to promiscuous dimer exchange in which either H2A.Z or H2A can be exchanged from nucleosomes. This result was confirmed in vivo, where genome-wide analysis demonstrated widespread decreases in H2A.Z levels in yeast mutants with hyperacetylated H3K56. Our work also suggests that a conserved SWR-C subunit may function as a "lock" that prevents removal of H2A.Z from nucleosomes. Our study identifies a histone modification that regulates a chromatin remodeling reaction and provides insights into how histone variants and nucleosome turnover can be controlled by chromatin regulators. PMID:23580526

  20. Texture Evolution and Twinning During the Expansion of Hot Extruded AZ31 + Sr Seamless Tubes

    NASA Astrophysics Data System (ADS)

    Sadeghi, Alireza; Martin, Étienne; Pekguleryuz, Mihriban

    2014-09-01

    Seamless tubes of AZ31, AZ31 + 0.4, and 0.8 wt pctSr were extruded at elevated temperatures. By compressing pure copper inserts inside the tubes, the extruded tubes were expanded at room and elevated temperatures [373 K and 473 K (100 °C and 200 °C)]. Microstructural examinations reveal the formation of twining in the as-extruded and expanded tubes. The amount of twinning decreased with increasing level of Sr in the expanded microstructures as a result of grain refinement and of decreasing Al in solution that facilitates dislocation motion. During expansion at room temperature, AZ31 shows higher elongation and lower strength than the alloys containing Sr. At 473 K (200 °C), compared to the lower temperatures, the Sr containing alloys exhibit lower flow stress and no fracture in the strain range investigated (40 pct reduction in cylinder height). The textures of the extruded alloys contain two main components named as RD (c-axis parallel to the radial direction) and HD (c-axis parallel to the hoop direction) based on their orientation with the sample coordinates. During expansion, extension twinning in the HD grains reorients the lattice to strengthen the RD and form a new ED (c-axis parallel to the extrusion direction) component. By increasing the temperature or level of Sr, the ED component is weakened due to the decrease in twinning. During expansion, the RD grains undergo contraction and double twining which reduce the overall texture strength.

  1. Texture Evolution and Twinning During the Expansion of Hot Extruded AZ31 + Sr Seamless Tubes

    NASA Astrophysics Data System (ADS)

    Sadeghi, Alireza; Martin, Étienne; Pekguleryuz, Mihriban

    2014-12-01

    Seamless tubes of AZ31, AZ31 + 0.4, and 0.8 wt pctSr were extruded at elevated temperatures. By compressing pure copper inserts inside the tubes, the extruded tubes were expanded at room and elevated temperatures [373 K and 473 K (100 °C and 200 °C)]. Microstructural examinations reveal the formation of twining in the as-extruded and expanded tubes. The amount of twinning decreased with increasing level of Sr in the expanded microstructures as a result of grain refinement and of decreasing Al in solution that facilitates dislocation motion. During expansion at room temperature, AZ31 shows higher elongation and lower strength than the alloys containing Sr. At 473 K (200 °C), compared to the lower temperatures, the Sr containing alloys exhibit lower flow stress and no fracture in the strain range investigated (40 pct reduction in cylinder height). The textures of the extruded alloys contain two main components named as RD ( c-axis parallel to the radial direction) and HD ( c-axis parallel to the hoop direction) based on their orientation with the sample coordinates. During expansion, extension twinning in the HD grains reorients the lattice to strengthen the RD and form a new ED ( c-axis parallel to the extrusion direction) component. By increasing the temperature or level of Sr, the ED component is weakened due to the decrease in twinning. During expansion, the RD grains undergo contraction and double twining which reduce the overall texture strength.

  2. Stamping of Thin-Walled Structural Components with Magnesium Alloy AZ31 Sheets

    SciTech Connect

    Chen, F.-K.; Chang, C.-K. [Department of Mechanical Engineering, National Taiwan University, Taipei, Taiwan (China)

    2005-08-05

    In the present study, the stamping process for manufacturing cell phone cases with magnesium alloy AZ31 sheets was studied using both the experimental approach and the finite element analysis. In order to determine the proper forming temperature and set up a fracture criterion, tensile tests and forming limit tests were first conducted to obtain the mechanical behaviors of AZ31 sheets at various elevated temperatures. The mechanical properties of Z31 sheets obtained from the experiments were then adopted in the finite element analysis to investigate the effects of the process parameters on the formability of the stamping process of cell phone cases. The finite element simulation results revealed that both the fracture and wrinkle defects could not be eliminated at the same time by adjusting blank-holder force or blank size. A drawbead design was then performed using the finite element simulations to determine the size and the location of drawbead required to suppress the wrinkle defect. An optimum stamping process, including die geometry, forming temperature, and blank dimension, was then determined for manufacturing the cell phone cases. The finite element analysis was validated by the good agreement between the simulation results and the experimental data. It confirms that the cell phone cases can be produced with magnesium alloy AZ31 sheet by the stamping process at elevated temperatures.

  3. Microstructure and temperature monitoring during the hot rolling of AZ31

    NASA Astrophysics Data System (ADS)

    Essadiqi, E.; Shehata, M. T.; Javaid, A.; Galvani, C.; Shen, G.; Yue, S.; Verma, R.

    2009-08-01

    This study details the microstructural evolution during hot rolling of AZ31 alloy sheet using a pilot-scale rolling mill. The aim is to understand the deformation mechanisms leading to grain refinement under industrial processing conditions and to design and optimize the hot rolling schedule for AZ31 in order to produce sheet with a fine and homogeneous microstructure. The study examined three different hot rolling temperatures, 350, 400, and 450°C, and two rolling speeds, 20 and 50 rpm. A total thickness reduction of 67% was obtained using multiple passes, with reductions of either 15% or 30% per pass. It was found that the microstructure of the AZ31 alloy was sensitive to the rolling temperature, the reduction (i.e., strain) per pass and the rolling speed (i.e., strain rate). The results show that the large cast grain structure is broken down by segmentation of the cast grain through localized deformation in twin bands, where dynamic recrystallization occurs in these bands as well as at the grain boundaries (necklacing).

  4. Tank 241-AZ-102 Privatization Push Mode Core Sampling and Analysis Plan

    SciTech Connect

    RASMUSSEN, J.H.

    1999-08-02

    This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for samples obtained from tank 241-AZ-102. The purpose of this sampling event is to obtain information about the characteristics of the contents of 241-AZ-102 required to satisfy the Data Quality Objectives For TWRS Privatization Phase I: Confirm Tank TIS An Appropriate Feed Source For High-Level Waste Feed Batch X(HLW DQO) (Nguyen 1999a), Data Quality Objectives For TWRS Privatization Phase 1: Confirm Tank TIS An Appropriate Feed Source For Low-Activity Waste Feed Batch X (LAW DQO) (Nguyen 1999b), Low Activity Waste and High Level Waste Feed Data Quality Objectives (L&H DQO) (Patello et al. 1999) and Characterization Data Needs for Development, Design, and Operation of Retrieval Equipment Developed through the Data Quality Objective Process (Equipment DQO) (Bloom 1996). The Tank Characterization Technical Sampling Basis document (Brown et al. 1998) indicates that these issues, except the Equipment DQO apply to tank 241-AZ-102 for this sampling event. The Equipment DQO is applied for shear strength measurements of the solids segments only. Poppiti (1999) requires additional americium-241 analyses of the sludge segments. Brown et al. (1998) also identify safety screening, regulatory issues and provision of samples to the Privatization Contractor(s) as applicable issues for this tank. However, these issues will not be addressed via this sampling event. Reynolds et al. (1999) concluded that information from previous sampling events was sufficient to satisfy the safety screening requirements for tank 241 -AZ-102. Push mode core samples will be obtained from risers 15C and 24A to provide sufficient material for the chemical analyses and tests required to satisfy these data quality objectives. The 222-S Laboratory will extrude core samples, composite the liquids and solids, perform chemical analyses, and provide subsamples to the Process Chemistry Laboratory. The Process Chemistry Laboratory will prepare test plans and perform process tests to evaluate the behavior of the 241-AZ-102 waste undergoing the retrieval and treatment scenarios defined in the applicable DQOs. Requirements for analyses of samples originating in the process tests will be documented in the corresponding test plan.

  5. H2A.Z acidic patch couples chromatin dynamics to regulation of gene expression programs during ESC differentiation.

    PubMed

    Subramanian, Vidya; Mazumder, Aprotim; Surface, Lauren E; Butty, Vincent L; Fields, Paul A; Alwan, Allison; Torrey, Lillian; Thai, Kevin K; Levine, Stuart S; Bathe, Mark; Boyer, Laurie A

    2013-01-01

    The histone H2A variant H2A.Z is essential for embryonic development and for proper control of developmental gene expression programs in embryonic stem cells (ESCs). Divergent regions of amino acid sequence of H2A.Z likely determine its functional specialization compared to core histone H2A. For example, H2A.Z contains three divergent residues in the essential C-terminal acidic patch that reside on the surface of the histone octamer as an uninterrupted acidic patch domain; however, we know little about how these residues contribute to chromatin structure and function. Here, we show that the divergent amino acids Gly92, Asp97, and Ser98 in the H2A.Z C-terminal acidic patch (H2A.Z(AP3)) are critical for lineage commitment during ESC differentiation. H2A.Z is enriched at most H3K4me3 promoters in ESCs including poised, bivalent promoters that harbor both activating and repressive marks, H3K4me3 and H3K27me3 respectively. We found that while H2A.Z(AP3) interacted with its deposition complex and displayed a highly similar distribution pattern compared to wild-type H2A.Z, its enrichment levels were reduced at target promoters. Further analysis revealed that H2A.Z(AP3) was less tightly associated with chromatin, suggesting that the mutant is more dynamic. Notably, bivalent genes in H2A.Z(AP3) ESCs displayed significant changes in expression compared to active genes. Moreover, bivalent genes in H2A.Z(AP3) ESCs gained H3.3, a variant associated with higher nucleosome turnover, compared to wild-type H2A.Z. We next performed single cell imaging to measure H2A.Z dynamics. We found that H2A.Z(AP3) displayed higher mobility in chromatin compared to wild-type H2A.Z by fluorescent recovery after photobleaching (FRAP). Moreover, ESCs treated with the transcriptional inhibitor flavopiridol resulted in a decrease in the H2A.Z(AP3) mobile fraction and an increase in its occupancy at target genes indicating that the mutant can be properly incorporated into chromatin. Collectively, our work suggests that the divergent residues in the H2A.Z acidic patch comprise a unique domain that couples control of chromatin dynamics to the regulation of developmental gene expression patterns during lineage commitment. PMID:23990805

  6. City of Cambridge: CityViewer

    NSDL National Science Digital Library

    What is the best way to experience the city of Cambridge, Massachusetts? You could read a history of Harvard University, take a walking tour, or perhaps browse a topical website. But why not look at the Cambridge CityViewer for edification? This unique tool "allows the public to view, query, mark up, and print custom maps using only a web browser." Notedly, the viewer works best with Internet Explorer or Mozilla Firefox. Visitors can check out ten different topical overlays, including those dealing with city parks, construction projects, land parcels, sewers, zoning, and traffic. There are many ways to get started, such as performing a simple search, an advanced search, or even just by typing in a street name and number. For anyone with an interest in urban history, planning, and land use, this site is a rare treat.

  7. Cities Centre University of Toronto

    E-print Network

    Sokolowski, Marla

    Cities Centre University of Toronto On the Mandate of the new University of Toronto Cities Centre selections from the Proposal for the Establishment of a Cities Centre at the University of Toronto December the University of Toronto Cities Centre. OBJECTIVES The overall objectives of the Cities Centre are to promote

  8. From intelligent to smart cities

    Microsoft Academic Search

    Mark Deakin; Husam Al Waer

    2011-01-01

    Drawing upon the smart experiences of ‘world class’ cities in N. America, Canada and Europe, this special issue draws together five papers from leading international experts on the transition from intelligent to smart cities. Together they do what Hollands (‘Will the real smart city stand up?’ City 12(3), 302–320) has recently asked of smart cities and provide the definitional components,

  9. AZ64 inhibits TrkB and enhances the efficacy of chemotherapy and local radiation in neuroblastoma xenografts

    PubMed Central

    Iyer, Radhika; Varela, Carly R.; Minturn, Jane E.; Ho, Ruth; Simpson, Anisha M.; Light, Jennifer E.; Evans, Audrey E.; Zhao, Huaqing; Thress, Kenneth; Brown, Jeffrey L.

    2014-01-01

    Neuroblastoma is a common pediatric tumor characterized by clinical heterogeneity. Because it is derived from sympathetic neuroblasts, the NTRK family of neurotrophin receptors plays an integral role in neuroblastoma cell survival, growth, and differentiation. Indeed, high expression of NTRK1 is associated with favorable clinical features and outcome, whereas expression of NTRK2 and its ligand, brain-derived neurotrophic factor (BDNF), are associated with unfavorable features and outcome. AZ64 (Astra Zeneca) is a potent and selective inhibitor of the NTRK tyrosine kinases that blocks phosphorylation at nanomolar concentrations. To determine the preclinical activity of AZ64, we performed intervention trials in a xenograft model with NTRK2-overexpressing neuroblastomas. AZ64 alone significantly inhibited tumor growth compared to vehicle-treated animals (p = 0.0006 for tumor size). Furthermore, the combination of AZ64 with conventional chemotherapeutic agents, irinotecan and temozolomide (irino–temo), showed significantly enhanced anti-tumor efficacy compared to irino–temo alone [(p < 0.0001 for tumor size, p < 0.0005 for event-free survival (EFS)]. We also assessed the combination of AZ64 and local radiation therapy (RT) on a neuroblastoma hindlimb xenograft model, and the efficacy of local RT was significantly increased when animals were treated simultaneously with AZ64 (p < 0.0001 for tumor size, p = 0.0006 for EFS). We conclude that AZ64 can inhibit growth of NTRK-expressing neuroblastomas both in vitro and in vivo. More importantly, it can significantly enhance the efficacy of conventional chemotherapy as well as local RT, presumably by inhibition of the NTRK2/BDNF autocrine survival pathway. PMID:22623209

  10. The Plains City Story

    ERIC Educational Resources Information Center

    van Olphen, Marcela; Rios, Francisco; Berube, William; Dexter, Robin; McCarthy, Robert

    2006-01-01

    This case study portrays a contemporary phenomenon that affects many U.S. school districts. Specifically, the authors address the challenges that the superintendent of the Plains City school district faced as a result of a change in the demographic distribution of his district. The gradual development of the pig farming industry in Plains City…

  11. Science Originals: Cities

    NSDL National Science Digital Library

    American Association for the Advancement of Science (AAAS; )

    2008-02-08

    People have a love-hate relationship with cities, for the opportunities they provide and the problems they create. This video presentation, an accompaniment to Science's 8 February 2008 special issue on cities, discusses some of the implications of rapid urbanization for our daily lives, our environment, and future sustainability.

  12. Utah: Salt Lake City

    Atmospheric Science Data Center

    2014-05-15

    ... for the 2002 Winter Olympics, to be held in Salt Lake City, Utah. The mountains surrounding Salt Lake City are renowned for the dry, ... view. The Uinta Mountains contain the highest peaks in Utah and are notable as the most prominent east-west trending range in the ...

  13. Walkout in Crystal City

    ERIC Educational Resources Information Center

    Barrios, Greg

    2009-01-01

    When students take action, they create change that extends far beyond the classroom. In this article, the author, who was a former teacher from Crystal City, Texas, remembers the student walkout that helped launch the Latino civil rights movement 40 years ago. The Crystal City student walkout remains a high point in the history of student activism…

  14. European cities: Towards a \\

    Microsoft Academic Search

    Mathis Stock

    2006-01-01

    The article puts forth the thesis that European cities are increasingly influenced by recreation, changing the essential quality of the urban space. I begin by setting out a theoretical framework in which cities are seen as specific places used as a resource by mobile individuals in a specific \\

  15. Air pollution in cities

    Microsoft Academic Search

    Helmut Mayer

    1999-01-01

    Air quality in cities is the result of a complex interaction between natural and anthropogenic environmental conditions. Air pollution in cities is a serious environmental problem – especially in the developing countries. The air pollution path of the urban atmosphere consists of emission and transmission of air pollutants resulting in the ambient air pollution. Each part of the path is

  16. The Happiness of Cities

    Microsoft Academic Search

    Charlotta Mellander; Peter J. Rentfrow

    2011-01-01

    Florida R., Mellander C. and Rentfrow P. J. The happiness of cities, Regional Studies. This research examines the factors that shape the happiness of cities, whereas much of the existent literature has focused on the happiness of nations. It is argued that in addition to income, which has been found to shape national-level happiness, human capital levels will play an

  17. Salt Lake City, Utah

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Salt Lake City, Utah, will host the 2002 Winter Olympic Games. The city is located on the southeastern shore of the Great Salt Lake and sits to the west of the Wasatch Mountains, which rise more than 3,500 meters (10,000 feet) above sea level. The city was first settled in 1847 by pioneers seeking relief from religious persecution. Today Salt Lake City, the capital of Utah, is home to more than 170,000 residents. This true-color image of Salt Lake City was acquired by the Enhanced Thematic Mapper Plus (ETM+), flying aboard Landsat 7, on May 26, 2000. The southeastern tip of the Great Salt Lake is visible in the upper left of the image. The furrowed green and brown landscape running north-south is a portion of the Wasatch Mountains, some of which are snow-capped (white pixels). The greyish pixels in the center of the image show the developed areas of the city. A number of water reservoirs can be seen east of the mountain range. Salt Lake City International Airport is visible on the northwestern edge of the city. About 20 miles south of the airport is the Bingham Canyon Copper Mine (tan pixels), the world's largest open pit excavation. See also this MODIS image of Utah. Image courtesy NASA Landsat7 Science Team and USGS Eros Data Center

  18. Smart City Components Architicture

    Microsoft Academic Search

    Mahmoud Al-Hader; A. Rodzi; A. R. Sharif; N. Ahmad

    2009-01-01

    The research is essentially to modularize the structure of utilities and develop a system for following up the activities electronically on the city scale. The GIS operational platform will be the base for managing the infrastructure development components with the systems interoperability for the available city infrastructure related systems. The concentration will be on the available utility networks in order

  19. Smart networked cities?

    Microsoft Academic Search

    Emmanouil Tranos; Drew Gertner

    2012-01-01

    This paper aims to critically assess the lack of a global inter-urban perspective in the smart city policy framework from a conceptual standpoint. We argue here that the smart city policy agenda should be informed by and address the structure of transnational urban networks as this can affect the efficiency of such local policies. The significance of this global network

  20. Exotic Decays Of A Heavy Neutral Higgs Through HZ/AZ Channel

    E-print Network

    Baradhwaj Coleppa; Felix Kling; Shufang Su

    2014-09-25

    Models of electroweak symmetry breaking with extended Higgs sectors are theoretically well motivated. In this study, we focus on the Two Higgs Doublet Model with a low energy spectrum containing scalars $H$ and a pseudoscalar $A$. We study the decays $A\\rightarrow HZ$ or $H\\rightarrow AZ$, which could reach sizable branching fractions in certain parameter regions. With detailed collider analysis, we obtain model independent exclusion bounds as well as discovery reach at the 14 TeV LHC for the process: $gg\\rightarrow A/H\\rightarrow HZ/AZ$, looking at final states bbll, \\tau\\tau ll and ZZZ(4l2j) for l =e,\\mu. We further interpret these bounds in the context of the Type II Two Higgs Doublet Model, considering three different classes of processes: $A\\rightarrow h^0Z$, $A\\rightarrow H^0Z$, and $H^0 \\rightarrow AZ$, in which $h^0$ and $H^0$ are the light and heavy CP-even Higgses respectively. For 100 fb$^{-1}$ integrated luminosity at the 14 TeV LHC, we find that for parent particle mass around 300-400 GeV, $A\\rightarrow h^0Z$ has the greatest reach when $H^0$ is interpreted as the 126 GeV Higgs: most regions in the tan\\beta-sin(\\beta-\\alpha) parameter space can be covered by exclusion and discovery. For 126 GeV $h^0$, only relatively small tan\\betaat the LHC and provides nice complementarity to conventional Higgs search channels.

  1. Texture Development in a Friction Stir Lap-Welded AZ31B Magnesium Alloy

    NASA Astrophysics Data System (ADS)

    Naik, B. S.; Chen, D. L.; Cao, X.; Wanjara, P.

    2014-09-01

    The present study was aimed at characterizing the microstructure, texture, hardness, and tensile properties of an AZ31B-H24 Mg alloy that was friction stir lap welded (FSLWed) at varying tool rotational rates and welding speeds. Friction stir lap welding (FSLW) resulted in the presence of recrystallized grains and an associated hardness drop in the stir zone (SZ). Microstructural investigation showed that both the AZ31B-H24 Mg base metal (BM) and SZ contained ?-Mg17Al12 and Al8Mn5 second phase particles. The AZ31B-H24 BM contained a type of basal texture (0001)<110> with the (0001) plane nearly parallel to the rolled sheet surface and <110> directions aligned in the rolling direction. FSLW resulted in the formation of another type of basal texture (0001)<100> in the SZ, where the basal planes (0001) became slightly tilted toward the transverse direction, and the prismatic planes (100) and pyramidal planes (101) exhibited a 30 deg + ( n - 1) × 60 deg rotation ( n = 1, 2, 3, …) with respect to the rolled sheet normal direction, due to the shear plastic flow near the pin surface that occurred from the intense local stirring. With increasing tool rotational rate and decreasing welding speed, the maximum intensity of the basal poles (0001) in the SZ decreased due to a higher degree of dynamic recrystallization that led to a weaker or more random texture. The tool rotational rate and welding speed had a strong effect on the failure load of FSLWed joints. A combination of relatively high welding speed (20 mm/s) and low tool rotational rate (1000 rpm) was observed to be capable of achieving a high failure load. This was attributed to the relatively small recrystallized grains and high intensity of the basal poles in the SZ arising from the low heat input as well as the presence of a small hooking defect.

  2. Molecular cloaking of H2A.Z on mortal DNA chromosomes during nonrandom segregation.

    PubMed

    Huh, Yang Hoon; Sherley, James L

    2011-10-01

    Although nonrandom sister chromatid segregation is a singular property of distributed stem cells (DSCs) that are responsible for renewing and repairing mature vertebrate tissues, both its cellular function and its molecular mechanism remain unknown. This situation persists in part because of the lack of facile methods for detecting and quantifying nonrandom segregating cells and for identifying chromosomes with immortal DNA strands, the cellular molecules that signify nonrandom segregation. During nonrandom segregation, at each mitosis, asymmetrically self-renewing DSCs continuously cosegregate to themselves the set of chromosomes that contain immortal DNA strands, which are the oldest DNA strands. Here, we report the discovery of a molecular asymmetry between segregating sets of immortal chromosomes and opposed mortal chromosomes (i.e., containing the younger set of DNA template strands) that constitutes a new convenient biomarker for detection of cells undergoing nonrandom segregation and direct delineation of chromosomes that bear immortal DNA strands. In both cells engineered with DSC-specific properties and ex vivo-expanded mouse hair follicle stem cells, the histone H2A variant H2A.Z shows specific immunodetection on immortal DNA chromosomes. Cell fixation analyses indicate that H2A.Z is present on mortal chromosomes as well but is cloaked from immunodetection, and the cloaking entity is acid labile. The H2A.Z chromosomal asymmetry produced by molecular cloaking provides a first direct assay for nonrandom segregation and for chromosomes with immortal DNA strands. It also seems likely to manifest an important aspect of the underlying mechanism(s) responsible for nonrandom sister chromatid segregation in DSCs. PMID:21905168

  3. City Lights of Europe

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Growth in 'mega-cities' is altering the landscape and the atmosphere in such a way as to curtail normal photosynthesis. By using data from The Defense Meteorological Satellite Program's Operational Linescan System, researchers have been able to look at urban sprawl by monitoring the emission of light from cities at night. By overlaying these 'light maps' onto other data such as soil and vegetation maps, the research shows that urbanization can have a variable but measurable impact on photosynthetic productivity. For more information, read Bright Lights, Big City Image by the NASA GSFC Scientific Visualization Studio

  4. Twins in asymmetrically rolled AZ31 analyzed with a Transmission Electron Microscope Orientation mapping tool

    NASA Astrophysics Data System (ADS)

    Rauch, E. F.; Forget, M.; Kapelski, G.

    2014-08-01

    An AZ31 sheet was rolled in symmetrical and asymmetrical conditions to a total reduction of 50%. Twins and double twins are the dominant structural features observed after deformation. They were analyzed systematically with the help of a dedicated TEM attachment that provides orientation maps at nanoscale. This particular characterization technic is similar to SEM-EBSD tools but far less sensitive to strains. Twinning is shown to differ substantially with the introduction of a shear component. Despite their frequency, it is argued that twins have little effect on the forming process.

  5. Evaluation of 241-AZ tank farm supporting phase 1 privatization waste feed delivery

    SciTech Connect

    CARLSON, A.B.

    1998-11-19

    This evaluation is one in a series of evaluations determining the process needs and assessing the adequacy of existing and planned equipment in meeting those needs at various double-shell tank farms in support of Phase 1 privatization. A number of tank-to-tank transfers and waste preparation activities are needed to process and feed waste to the private contractor in support of Phase 1 privatization. The scope of this evaluation is limited to process needs associated with 241-AZ tank farm during the Phase 1 privatization.

  6. Low temperature superplasticity in an AZ91 magnesium alloy processed by ECAE

    SciTech Connect

    Mabuchi, M. [National Industrial Research Inst. of Nagoya (Japan)] [National Industrial Research Inst. of Nagoya (Japan); Iwasaki, H.; Yanase, K. [Himeji Inst. of Tech., Himeji, Hyogo (Japan)] [Himeji Inst. of Tech., Himeji, Hyogo (Japan); Higashi, K. [Osaka Prefecture Univ., Sakai, Osaka (Japan)] [Osaka Prefecture Univ., Sakai, Osaka (Japan)

    1997-03-15

    Magnesium alloys are especially suitable for use of the structural components in aerospace and outerspace applications due to their low density. In general, however, magnesium alloys have poor workability because of their h.c.p. structure. Therefore it is desirable to improve the poor workability, and superplastic forming is expected to be put into the processing in practical applications. In the present work, equal channel angular extrusion (ECAE), which allows one to attain high shear strain, has been conducted on an AZ91 magnesium alloy. The alloy processed by ECAE exhibited superplastic behavior at low temperatures of 448 and 473 K, which are about 0.5T{sub m}.

  7. Exotic decays of a heavy neutral Higgs through HZ/AZ channel

    NASA Astrophysics Data System (ADS)

    Coleppa, Baradhwaj; Kling, Felix; Su, Shufang

    2014-09-01

    Models of electroweak symmetry breaking with extended Higgs sectors are theoretically well motivated. In this study, we focus on the Two Higgs Doublet Model with a low energy spectrum containing scalars H and a pseudoscalar A. We study the decays A ? HZ or H ? AZ, which could reach sizable branching fractions in certain parameter regions. With detailed collider analysis, we obtain model independent exclusion bounds as well as discovery reach at the 14 TeV LHC for the process: gg ? A/ H ? HZ/ AZ, looking at final states bb??, ???? and ZZZ(4 ? + 2 j) for ? = e, ?. We further interpret these bounds in the context of the Type II Two Higgs Doublet Model, considering three different classes of processes: A ? h 0 Z, A ? H 0 Z, and H 0 ? AZ, in which h 0 and H 0 are the light and heavy CP-even Higgses respectively. For 100 fb-1 integrated luminosity at the 14 TeV LHC, we find that for parent particle mass around 300-400 GeV, A ? h 0 Z has the greatest reach when H 0 is interpreted as the 126 GeV Higgs: most regions in the tan ? versus sin( ? - ?) plane can be excluded and a significant fraction at small and large tan ? can be covered by discovery. For 126 GeV h 0, only relatively small tan ? ? 10 (5) can be reached by exclusion (discovery) while a wide range of sin( ? - ?) is accessible. For A ? H 0 Z, the reach is typically restricted to sin( ? - ?) ~ ±1 with tan ? ? 10 in bb?? and ???? channels. The ZZZ(4 ?2 j) channel, on the other hand, covers a wide range of 0 .3 < | sin( ? - ?)| < 1 for tan ? ? 4. H 0 ? AZ typically favors negative values of sin( ? - ?), with exclusion/discovery reach possibly extending to all values of tan ?. A study of exotic decays of extra Higgses appearing in extensions of the Standard Model would extend the reach at the LHC and provides nice complementarity to conventional Higgs search channels.

  8. Barium phosphate conversion coating on die-cast AZ91D magnesium alloy

    Microsoft Academic Search

    Feng LIU; Da-yong SHAN; En-hou HAN; Chang-sheng LIU

    2008-01-01

    Poor corrosion resistance limits the application of magnesium alloys. Conversion coating is widely used to protect magnesium alloys because of easy operation and low cost. A novel conversion coating on die-cast AZ91D magnesium alloy containing barium salts was studied. The optimum concentrations of Ba(NO3)2, Mn(NO3)2 and NH4H2PO4 are 25 g\\/L, 15 mL\\/L and 20 g\\/L, respectively, based on orthogonal test

  9. Thermal stability and diffusion studies in the Au and Bi implanted AZ1350 photoresist

    NASA Astrophysics Data System (ADS)

    Behar, M.; Amaral, L.; Zawislak, F. C.; Guimarães, R. B.; Fink, D.

    1990-02-01

    The thermal stability of Au and Bi implanted AZ1350 photoresist films has been investigated via Rutherford backscattering spectrometry. It is observed that the unimplanted photoresist starts to decompose at 200°C. A shallow implantation of Bi and Au produces similar damage in the film but only the Bi implanted sample displays a marked improvement in the thermal stability (up to 350°C). This indicates that, besides radiation damage, chemical effects also play a role in the improvement of the photoresist's thermal stability. The thermal behaviour of Au and Bi implanted in the photoresist has also been studied. It was found that Bi diffuses regularly while Au follows an irregular diffusion process.

  10. GPHY 421 Sustainable Cities Prof. Ulrich Kamp 1 SUSTAINABLE CITIES

    E-print Network

    Vonessen, Nikolaus

    architecture, and urban forestry and agriculture. We will discuss how sustainable cities of today are, and howGPHY 421 ­ Sustainable Cities ­ Prof. Ulrich Kamp 1 SUSTAINABLE CITIES (GPHY 421) - Fall 2011 of sustainability efforts in cities around the world. Topics include, for example, urban sprawl and smart growth

  11. Light in the city

    E-print Network

    Srinivasan, Kavita, 1976-

    2002-01-01

    This thesis focuses on enhancing the awareness of light for the pedestrian,and using light as a way of revealing the structure of the city and its relation to the cosmos. It proposes that aesthetic qualities of light inform ...

  12. Transforming Cities With Transit

    NSDL National Science Digital Library

    Cervero, Robert.

    How are cities transformed by the creation of new transit lines? How can existing transit lines be modified to create new land use opportunities for housing and commercial properties? These subjects are covered by a 172-page conference edition of a forthcoming paper from the World Bank. The paper was authored by Hiroaki Suzuki, Robert Cervero, and Kanako Iuchi. Visitors will note that the work focuses on "identifying barriers to and opportunities for effective coordination of transport infrastructure and urban development." The work takes on a number of global best practices of transit-oriented metropolises that have direct relevance to cities in developing countries and offers both analysis and suggestions for future projects. Sections here include "Lessons from Sustainable Transit-Oriented Cities," "Integrating Transit and Urban Development in Cities in the Developing World," and "Toward Sustainable Urban Futures."

  13. The 3Cities Project

    NSDL National Science Digital Library

    Based at the Universities of Nottingham and Birmingham, the 3Cities Project is "an inter- and multi-disciplinary study of the iconography, spatial forms and literary and visual cultures of New York City, Chicago and Los Angeles in the period 1870s to 1930s." At present, the site hosts a collection of essays on the three cities, information on the project as a whole, and links and information for related conferences and seminars. The Project has also posted on a different site the City Sites electronic book, a collection of ten multimedia essays on New York and Chicago. Visitors can access these essays via interactive maps, a list, or by following theme-based "pathways." A lengthy bibliography rounds out the site.

  14. Sister Cities International

    NSDL National Science Digital Library

    People from around the world have sought to establish links with other individuals from different nations, and since 1956, cities have sought to also establish meaningful relationships with other urban areas through the Sister Cities International organization. Currently, the organization represents more than 2,500 communities in 126 countries. Visitors to the site can learn which cities are currently seeking partnerships with other cities, read about the organization's annual conference, and also read about the programs they administer. Also, its calendar of events is quite full with programs designed for the general public, such as those dealing with relationships with countries in the Middle East and the question of local government. Finally, the material on the site is available in a number of different languages, including French, German, Spanish, and Japanese.

  15. City sewer collectors biocorrosion

    NASA Astrophysics Data System (ADS)

    Ksia¸?ek, Mariusz

    2014-12-01

    This paper presents the biocorrosion of city sewer collectors impregnated with special polymer sulphur binders, polymerized sulphur, which is applied as the industrial waste material. The city sewer collectors are settled with a colony of soil bacteria which have corrosive effects on its structure. Chemoautotrophic nitrifying bacteria utilize the residues of halites (carbamide) which migrate in the city sewer collectors, due to the damaged dampproofing of the roadway and produce nitrogen salts. Chemoorganotrophic bacteria utilize the traces of organic substrates and produce a number of organic acids (formic, acetic, propionic, citric, oxalic and other). The activity of microorganisms so enables the origination of primary and secondary salts which affect physical properties of concretes in city sewer collectors unfavourably.

  16. Design a Solar City

    NSDL National Science Digital Library

    Integrated Teaching and Learning Program,

    Students design and build a model city powered by the sun! They learn about the benefits of solar power, and how architectural and building engineers integrate photovoltaic panels into the design of buildings.

  17. Between house and city

    E-print Network

    Kallus, Rachel Admati

    1982-01-01

    In an attempt to understand the relationships between a residential building type and the city, this thesis explores the quality of the urban context resulting from the assemblage of these buildings. The investigation takes ...

  18. Art in Cities

    NSDL National Science Digital Library

    The organizers of Art in Cities say, "Cities are like a huge art gallery with a permanently changing exhibition." Therefore, this web site exists to collect submissions of artwork from cities all over the world, and plot it on a map. To view the art, browse by selecting points on the map, or search by City, Submitter, or artist (Artwork by). There is also a quick link to the most recent uploads. On the day we visited, this link lead to stencil art and graffiti from several cities in the Netherlands, including Amsterdam, Rotterdam, and Eindhoven, as well as one from San Bernardino, CA. This was just the first page of 473 for this specific link, which is in turn only a fraction of the close to 6,000 pieces of art on view at the site. Submitting art is as easy as uploading an image from your computer, and filling out a few fields on a form thus encouraging anyone to walk the streets of their city looking for art to add the site.

  19. American Solar Energy Society Proc. ASES Annual Conference, Phoenix, AZ, May 2010 IMPROVING THE PERFORMANCE OF SATELLITE-TO-IRRADIANCE MODELS USING

    E-print Network

    Perez, Richard R.

    © American Solar Energy Society ­ Proc. ASES Annual Conference, Phoenix, AZ, May 2010 IMPROVING;© American Solar Energy Society ­ Proc. ASES Annual Conference, Phoenix, AZ, May 2010 between the snow-to-irradiance model designed to complement the existing SUNY model used in the US National Solar Resource Data Base

  20. Volunteer Application Please return application to: Kellee Ellingson | kelleeh@email.arizona.edu | Gould-Simpson 929B | 1040 E. 4th Street | Tucson, AZ 85721

    E-print Network

    Fay, Noah

    @email.arizona.edu | Gould-Simpson 929B | 1040 E. 4th Street | Tucson, AZ 85721 Fax: (520) 626-1352 | For more information | kelleeh@email.arizona.edu | Gould-Simpson 929B | 1040 E. 4th Street | Tucson, AZ 85721 Fax: (520) 626

  1. Histone H2A (H2A.X and H2A.Z) Variants in Molluscs: Molecular Characterization and Potential Implications

    E-print Network

    Eirin Lopez, Jose Maria

    Histone H2A (H2A.X and H2A.Z) Variants in Molluscs: Molecular Characterization and Potential in most organisms, specially protostome animals. Molluscs (which represent sentinel organisms. (2012) Histone H2A (H2A.X and H2A.Z) Variants in Molluscs: Molecular Characterization and Potential

  2. From intelligent to smart cities

    Microsoft Academic Search

    Mark Deakin; Husam Al Waer

    2011-01-01

    Taking Hollands' previous statement on the transition from intelligent to smart cities as its point of departure (‘Will the real smart city stand up?’ City 12(3), 302–320), this article reflects upon the anxieties currently surrounding such developments. In particular, it considers the suggestion that such developments have more to do with cities meeting the corporate needs of marketing campaigns than

  3. CHARACTERIZATION AND FORMABILITY OF CONTINUOUS-CAST AZ31B MAGNESIUM ALLOY SHEETS

    SciTech Connect

    Rohatgi, Aashish; Herling, Darrell R.; Nyberg, Eric A.

    2009-09-24

    The goal of this work is to understand the inter-relationship between the initial properties of continuous-cast magnesium alloy (AZ31B) sheets and their subsequent formability and post-formed mechanical performance for use in cost-effective, lightweight, automotive body panels. As-received sheets, provided by the Automotive Metals Division (AMD-602) team, were characterized by surface roughness measurements using mechanical profilometry. The arithmetic mean deviation of profile (Ra) and the maximum two-point height of profile (Ry) of the as-received sheets ranged from ~0.2-2 ?m and ~2-15 ?m, respectively. Several commercial lubricants were evaluated by thermal analysis and the liquid phase of the lubricants was found to evaporate/decompose upon heating leaving behind a solid residue upon heating to temperatures exceeding ~125-150°C. Elevated temperature bending-under-tension (BUT) friction tests were conducted at 350°C and the coefficient-of-friction values ranged from a minimum of ~0.1 (for tungsten disulfide lubricant) to ~0.7 when no lubricant was used. These results, in conjunction with those from the forming trials conducted by the AMD-602 team, will be eventually used to determine the role of sheet-die friction in determining the formability of AZ31B sheets.

  4. Surface composite nanostructures of AZ91 magnesium alloy induced by high current pulsed electron beam treatment

    NASA Astrophysics Data System (ADS)

    Li, M. C.; Hao, S. Z.; Wen, H.; Huang, R. F.

    2014-06-01

    High current pulsed electron beam (HCPEB) treatment was conducted on an AZ91 cast magnesium alloy with accelerating voltage 27 kV, energy density 3 J/cm2 and pulse duration 2.5 ?s. The surface microstructure was characterized by optical microscope (OM), X-ray diffraction (XRD), scanning electron microscope (SEM) equipped with energy dispersive spectrometer (EDS), and transmission electron microscope (TEM). The surface corrosion property was tested with electrochemical method in 3.5 wt.% NaCl solution. It is found that after 1 pulse of HCPEB treatment, the initial eutectic ? phase and Mg17Al12 particles started to dissolve in the surface modified layer of depth ˜15 ?m. When using 15 HCPEB pulses, the Al content in surface layer increased noticeably, and the phase structure was modified as composite nanostructures consisted of nano-grained Mg3.1Al0.9 domains surrounded by network of Mg17Al12 phase. The HCPEB treated samples showed an improved corrosion resistance with cathodic current density decreased by two orders of magnitude as compared to the initial AZ91 alloy.

  5. Electrophoretic deposition of nanostructured hydroxyapatite coating on AZ91 magnesium alloy implants with different surface treatments

    NASA Astrophysics Data System (ADS)

    Rojaee, Ramin; Fathi, Mohammadhossein; Raeissi, Keyvan

    2013-11-01

    Bio-absorbable magnesium (Mg) based alloys have been introduced as innovative orthopedic implants during recent years. It has been specified that rapid degradation of Mg based alloys in physiological environment should be restrained in order to be utilized in orthopedic trauma fixation and vascular intervention. In this developing field of healthcare materials, micro-arc oxidation (MAO), and MgF2 conversion coating were exploited as surface pre-treatment of AZ91 magnesium alloy to generate a nanostructured hydroxyapatite (n-HAp) coating via electrophoretic deposition (EPD) method. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM) techniques were used to characterize the obtained powder and coatings. The potentiodynamic polarization tests were carried out to evaluate the corrosion behavior of the coated and uncoated specimens, and in vitro bioactivity evaluation were performed in simulated body fluid. Results revealed that the MAO/n-HAp coated AZ91 Mg alloy samples with a rough topography and lower corrosion current density leads to a lower Mg degradation rate accompanied by high bioactivity.

  6. Project W-151 Tank 101-AZ Waste Retrieval System Year 2000 Compliance Assessment Project Plan

    SciTech Connect

    BUSSELL, J.H.

    1999-08-02

    This assessment describes the potential Year 2000 (Y2K) problems and describes the methods for achieving Y2K compliance for Project W-151, Tank 101-AZ Waste Retrieval System. The purpose of this assessment is to give an overview of the project. This document will not be updated and any dates contained in this document are estimates and may change. Two mixer pumps and instrumentation have been or are planned to be installed in waste tank 101-AZ to demonstrate solids mobilization. The information and experience gained during this process test will provide data for comparison with sludge mobilization prediction models and provide indication of the effects of mixer pump operation on an Aging Waste Facility tank. A limited description of system dates, functions, interfaces, potential Y2K problems, and date resolutions is presented. The project is presently on hold, and definitive design and procurement have been completed. This assessment will describe the methods, protocols, and practices to ensure that equipment and systems do not have Y2K problems.

  7. Identification of an advanced constitutive model of Magnesium alloy AZ31B

    SciTech Connect

    Liu, Z. G.; Massoni, E. [CEMEF, Centre de Mise en Forme des Materiaux, Ecole Nationale Superieure des Mines de Paris 1, rue Claude Daunesse, BP 207, 06904, Sophia-Antipolis Cedex (France)

    2011-05-04

    The main aim of this paper is to study the flow behavior of the AZ31B magnesium alloy by means of tensile tests performed in extended ranges of temperature and strain rates. The flow stress-strain curves analyzed by power law type constitutive equation can only fit well with experimental curves at the work-hardening stage. A new mathematical model is studied to describe the softening behavior of material based on tensile experiments. The relative parameters are obtained by fitting the equation with the experimental data. The genetic algorithm has been used to obtain the global optimal fitting parameters. The comparison between the fitted and experimental data proves the effectiveness of the model. The results indicate that this model leads to a better simulation of the flow stress during the softening stage than that of the power law equation. Based on this model, the deep drawing process has been simulated with the commercial finite element code FORGE registered. The punch load and thickness distribution of AZ31 sheet have been studied. The study of the results is helpful to the application of the stamping technology for the magnesium alloy sheet.

  8. Characterization of AZ31B wrought magnesium alloy joints welded by high power fiber laser

    SciTech Connect

    Wang Zemin; Gao Ming, E-mail: mgao@mail.hust.edu.cn; Tang Haiguo; Zeng Xiaoyan

    2011-10-15

    A 6 kW fiber laser is used to weld AZ31B wrought magnesium alloy and the characterization of welded joints are studied by the observations of bead size, microstructure and mechanical properties. The accepted joints without macro-defects can be obtained when the laser power is in the range of 2.5 to 4.0 kW. Typical hexagonal dendrites are observed in the fusion zone, whose average semi-axis length increases with increasing heat input or decreasing welding speed. The minimum ultimate tensile strength of welded joints reaches 227 MPa, 94.6% of the base metal. And when the heat input reduces to 48 J/mm or lower, the joints are fractured in the base metal, showing stronger failure strength compared to the base metal. For the joints ruptured in the weld metal, the fracture surface is characterized by a ductile-brittle mixed pattern consisting of both dimples and cleavages. Finally, the formation mechanism of pore in the welds is discussed and summarized by the pore morphologies on the fracture surface. - Highlights: {yields} Accepted joints of AZ31B Mg alloy are produced by high power fiber laser. {yields} Optimal welding parameters are summarized by experimental observations. {yields} Obvious hexagonal dendrites are observed in the fusion zone. {yields} The joints are stronger than base metal as the heat input is lower than 48 J/mm. {yields} Pore formation mechanism of welded joints is discussed and summarized.

  9. Research on microstructures of sub-rapidly solidified AZ61 Magnesium Alloy

    SciTech Connect

    Teng Haitao, E-mail: seantht@yahoo.com.cna [Key Laboratory for Materials Modification by Laser, Ion and Electron Beams, Ministry of Education (China); School of Materials Science and Engineering, Dalian University of Technology, Dalian 116085 (China); Zhang Xiaoli; Zhang Zhongtao [Key Laboratory for Materials Modification by Laser, Ion and Electron Beams, Ministry of Education (China); School of Materials Science and Engineering, Dalian University of Technology, Dalian 116085 (China); Li Tingju, E-mail: tjuli@dlut.edu.cn [Key Laboratory for Materials Modification by Laser, Ion and Electron Beams, Ministry of Education (China); School of Materials Science and Engineering, Dalian University of Technology, Dalian 116085 (China); Cockcroft, Steve [Department of Materials Engineering, University of British Columbia, Vancouver (Canada)

    2009-06-15

    AZ61 magnesium alloy foils of 0.5-3.0 mm thick were successfully produced by using sub-rapid solidification technique. Microstructures of conventionally solidified (CS) and sub-rapidly solidified (sub-RS) alloys were examined by optical microscope (OM) and scanning electron microscope (SEM). The results showed that the cellular grain of 1.8-13.5 {mu}m can be obtained during sub-rapid solidification process. Phase compositions and microdistribution of the alloying elements in the foils were analyzed by X-ray diffraction (XRD) and electron probe microanalyzer (EPMA), respectively. The eutectic transformation L {yields} {alpha}-Mg + {beta}-Mg{sub 17}Al{sub 12} and microsegregation in conventionally solidified AZ61 alloy were remarkably suppressed in sub-rapid solidification process. As a consequence, the alloying elements Al, Zn, Mn showed much higher solid solubility and the sub-rapid solidification microstructures dominantly consisted of supersaturated {alpha}-Mg solid solution. Meanwhile, the {beta}-Mg{sub 17}Al{sub 12} phases located in the {alpha}-Mg grain boundaries are largely decreased due to high solidification cooling rate.

  10. Geologie study off gravels of the Agua Fria River, Phoenix, AZ

    USGS Publications Warehouse

    Langer, W.H.; Dewitt, E.; Adams, D.T.; O'Briens, T.

    2010-01-01

    The annual consumption of sand and gravel aggregate in 2006 in the Phoenix, AZ metropolitan area was about 76 Mt (84 million st) (USGS, 2009), or about 18 t (20 st) per capita. Quaternary alluvial deposits in the modern stream channel of the Agua Fria River west of Phoenix are mined and processed to provide some of this aggregate to the greater Phoenix area. The Agua Fria drainage basin (Fig. 1) is characterized by rugged mountains with high elevations and steep stream gradients in the north, and by broad alluvial filled basins separated by elongated faultblock mountain ranges in the south. The Agua Fria River, the basin’s main drainage, flows south from Prescott, AZ and west of Phoenix to the Gila River. The Waddel Dam impounds Lake Pleasant and greatly limits the flow of the Agua Fria River south of the lake. The southern portion of the watershed, south of Lake Pleasant, opens out into a broad valley where the river flows through urban and agricultural lands to its confluence with the Gila River, a tributary of the Colorado River.

  11. Inverse Identification of the Dynamic Recrystallization Parameters for AZ31 Magnesium Alloy Using BP Neural Network

    NASA Astrophysics Data System (ADS)

    Lou, Yan; Wu, Wenhua; Li, Luoxing

    2012-07-01

    The effect of the dynamic recrystallization (DRX) parameters are of prime importance to improve the accuracy of the numerical simulation of hot forming processes for metals. However, it is difficult to determine the values of DRX parameters from experiments because of the influence of various factors, such as temperature, etc. In the present study, the DRX parameters for AZ31 magnesium alloy are identified by using the method of inverse analysis based on measured stress, BP neural network algorithm, genetic algorithm (GA), orthogonal experiment, and numerical simulation. Then, by applying the identified parameters in finite element analysis, the comparison between the numerically calculated and the experimental results is made to verify the correctness of the method. The results show that the numerically calculated stress, strain, recrystallized fraction, and average grain size valus are in good agreement with the experimental ones. These results demonstrate that the method of inverse analysis is a feasible and an effective tool for determination of the AZ31 DRX parameters.

  12. Research on the drawing process with a large total deformation wires of AZ31 alloy

    NASA Astrophysics Data System (ADS)

    Bajor, T.; Muskalski, Z.; Suliga, M.

    2010-07-01

    Magnesium and their alloys have been extensively studied in recent years, not only because of their potential applications as light-weight engineering materials, but also owing to their biodegradability. Due to their hexagonal close-packed crystallographic structure, cold plastic processing of magnesium alloys is difficult. The preliminary researches carried out by the authors have indicated that the application of the KOBO method, based on the effect of cyclic strain path change, for the deformation of magnesium alloys, provides the possibility of obtaining a fine-grained structure material to be used for further cold plastic processing with large total deformation. The main purpose of this work is to present research findings concerning a detailed analysis of mechanical properties and changes occurring in the structure of AZ31 alloy wire during the multistage cold drawing process. The appropriate selection of drawing parameters and the application of multistep heat treatment operations enable the deformation of the AZ31 alloy in the cold drawing process with a total draft of about 90%.

  13. Effects of heat input on microstructure and tensile properties of laser welded magnesium alloy AZ31

    SciTech Connect

    Quan, Y.J. [School of Materials Science and Engineering, Hunan University, Changsha 410082 (China)], E-mail: quanyj_2006@yahoo.com.cn; Chen, Z.H.; Gong, X.S.; Yu, Z.H. [School of Materials Science and Engineering, Hunan University, Changsha 410082 (China)

    2008-10-15

    A 3 kW CO{sub 2} laser beam was used to join wrought magnesium alloy AZ31 sheets, and the effects of heat input on the quality of butt welding joints were studied. By macro and microanalysis, it is found that the welding heat input plays an important role in laser welding process for AZ31 wrought sheets. After welding, the grains far from the weld centre present the typical rolled structure. But the microstructure out of the fusion zone gradually changes to complete equiaxed crystals as the distance from the weld centre decreases. Adjacent to the fusion boundary, there is a band region with columnar grains, and its growth direction is obviously perpendicular to the solid/liquid line. The microstructure in fusion centre consists of fine equiaxed grains and the many precipitated particles are brittle phase Mg{sub 17}Al{sub 12} or Mg{sub 17}(Al,Zn){sub 12}. With increasing the heat input, the band width of columnar grains varies, the grains in fusion zone get coarser, and the distribution of precipitates changes from intragranularly scattered particles to intergranularly packed ones. The results of tensile test show that the change trend of ultimate tensile strength (UTS) and elongation of the welded joints is to increase at first and then decrease with the heat input increasing. When the heat input reaches 24 J mm{sup -1}, the maximum value of the UTS is up to 96.8% of the base metal.

  14. Forming Analysis of AZ31 Magnesium Alloy Sheets by Means of a Multistep Inverse Approach

    SciTech Connect

    Nguyen, Ba Nghiep; Bapanapalli, Satish K.

    2009-04-01

    This paper applies a multi-step inverse approach to predict the forming of AZ31 magnesium alloy sheets. An in-house finite element code named “INAPH”, which implements the inverse approach formulation by Guo et al. (Int. J. Numer. Methods Eng., 30, 1385-1401), has been used for the forming analysis. This inverse approach uses the deformation theory of plasticity and assumes that the deformation is independent of the loading history. Failure during forming is predicted by a stress-based criterion or a forming limit diagram-based criterion. The INAPH predictions have been compared with experimental results of Takuda et al (Journal of Materials Processing Technology, 89-90:135-140) and incremental analysis using ABAQUS. The multi-step inverse analysis has been shown to very quickly and fairly accurately predict stress, plastic strain, thickness distributions and failure locations on deeply drawn parts made of AZ31 magnesium alloy. The capability of INAPH to predict the formability of magnesium alloys has also been demonstrated at various temperatures. As magnesium alloys possess very limited formability at room temperature, and their formability becomes better at higher temperatures (> 100oC), the inverse analysis constitutes an efficient and valuable tool to predict forming of magnesium alloy parts as a function of temperature. In addition, other processing and design parameters such as the initial dimensions, final desired shape, blank holder forces, and friction can be quickly adjusted to assess the forming feasibility.

  15. Fatigue properties of magnesium alloy AZ91 processed by severe plastic deformation.

    PubMed

    Fintová, Stanislava; Kunz, Ludvík

    2015-02-01

    Fatigue properties of cast AZ91 magnesium alloy processed by severe plastic deformation were investigated and compared with the properties of the initial cast state. The severe plastic deformation was carried out by equal channel angular pressing (ECAP). The ECAP treatment resulted in a bimodal structure. The bimodality consists in a coexistence of fine grained areas with higher content of Mg17Al12 particles and areas exhibiting larger grains and lower density of Mg17Al12 particles. Improvement of the basic mechanical properties of AZ91 (yield stress, tensile strength and ductility) by ECAP was significant. Also the improvement of the fatigue life in the low-cycle fatigue region was substantial. However the improvement of the fatigue strength in the high-cycle fatigue region was found to be negligible. The endurance limit based on 10(7) cycles for the cast alloy was 80 MPa and for the alloy processed by ECAP 85 MPa. The cyclic plastic response in both states was qualitatively similar; initial softening was followed by a long cyclic hardening. Fatigue cracks in cast alloy initiate in cyclic slip bands which were formed in areas of solid solution. In the case of severe plastic deformed material with bimodal structure two substantially different mechanisms of crack initiation were observed. Crack initiation in slip bands was a preferred process in the areas with large grains whereas the grain boundaries cracking was a characteristic mechanism in the fine grained regions. PMID:25498295

  16. Experimental investigation of anisotropy evolution of AZ31 magnesium alloy sheets under tensile loading

    SciTech Connect

    Tari, D. Ghaffari; Worswick, M. J. [University of Waterloo, 200 University Ave West, Waterloo, Ontario (Canada)

    2011-05-04

    Increasing demand for lighter final products has created new opportunities for the application of new light weight materials. Due to high strength to density ratio and good magnetic resistance properties, magnesium alloys are good candidates to replace steel and aluminum for same application. However, limited numbers of active slip deformation mechanisms, result in a decreased formability at room temperature. Furthermore, wrought magnesium alloys have an initial crystallographic texture, remained from the prior rolling operations, which makes them highly anisotropic. In this paper, tensile tests are performed at room temperature and 200 deg. C at different strain rates and orientations relative to the rolling direction, including rolling, 30 deg., 45 deg., 60 deg. and transverse orientation. The strain rates adopted for these experiments varied from 0.001 to 1.0. The testing results show the effect of temperature on the strain rate sensitivity of AZ31 sheets. The extent of deformation is continuously recorded using two separate high temperature extensometers. The results of testing show an increase in the r-values with the plastic deformation. The strain rate sensitivity of AZ31 increased as the temperature was elevated. At higher strain rates the measured r-values are larger and the slope of its evolution with the plastic strain is steeper.

  17. Laser surface modification of AZ31B?Mg alloy for bio-wettability.

    PubMed

    Ho, Yee-Hsien; Vora, Hitesh D; Dahotre, Narendra B

    2015-02-01

    Magnesium alloys are the potential degradable materials for load-bearing implant application due to their comparable mechanical properties to human bone, excellent bioactivity, and in vivo non-toxicity. However, for a successful load-bearing implant, the surface of bio-implant must allow protein absorption and layer formation under physiological environment that can assist the cell/osteoblast growth. In this regard, surface wettability of bio-implant plays a key role to dictate the quantity of protein absorption. In light of this, the main objective of the present study was to produce favorable bio-wettability condition of AZ31B Mg alloy bio-implant surface via laser surface modification technique under various laser processing conditions. In the present efforts, the influence of laser surface modification on AZ31B Mg alloy surface on resultant bio-wettability was investigated via contact-angle measurements and the co-relationships among microstructure (grain size), surface roughness, surface energy, and surface chemical composition were established. In addition, the laser surface modification technique was simulated by computational (thermal) model to facilitate the prediction of temperature and its resultant cooling/solidification rates under various laser processing conditions for correlating with their corresponding composition and phase evolution. These predicted thermal properties were later used to correlate with the corresponding microstructure, chemical composition, and phase evolution via experimental analyses (X-ray diffractometer, scanning electron microscope, energy-dispersive spectroscopy). PMID:25201909

  18. Characterization of fold defects in AZ91D and AE42 magnesium alloy permanent mold castings

    SciTech Connect

    Bichler, L. [Centre for Near-net-shape Processing of Materials, Ryerson University, 101 Gerrard St. E., Toronto, M5B 2K3 (Canada); Ravindran, C., E-mail: rravindr@ryerson.ca [Centre for Near-net-shape Processing of Materials, Ryerson University, 101 Gerrard St. E., Toronto, M5B 2K3 (Canada)

    2010-03-15

    Casting premium-quality magnesium alloy components for aerospace and automotive applications poses unique challenges. Magnesium alloys are known to freeze rapidly prior to filling a casting cavity, resulting in misruns and cold shuts. In addition, melt oxidation, solute segregation and turbulent metal flow during casting contribute to the formation of fold defects. In this research, formation of fold defects in AZ91D and AE42 magnesium alloys cast via the permanent mold casting process was investigated. Computer simulations of the casting process predicted the development of a turbulent metal flow in a critical casting region with abrupt geometrical transitions. SEM and light optical microscopy examinations revealed the presence of folds in this region for both alloys. However, each alloy exhibited a unique mechanism responsible for fold formation. In the AZ91D alloy, melt oxidation and velocity gradients in the critical casting region prevented fusion of merging metal front streams. In the AE42 alloy, limited solubility of rare-earth intermetallic compounds in the {alpha}-Mg phase resulted in segregation of Al{sub 2}RE particles at the leading edge of a metal front and created microstructural inhomogeneity across the fold.

  19. Identification of an advanced constitutive model of Magnesium alloy AZ31B

    NASA Astrophysics Data System (ADS)

    Liu, Z. G.; Massoni, E.

    2011-05-01

    The main aim of this paper is to study the flow behavior of the AZ31B magnesium alloy by means of tensile tests performed in extended ranges of temperature and strain rates. The flow stress-strain curves analyzed by power law type constitutive equation [1] can only fit well with experimental curves at the work-hardening stage. A new mathematical model is studied to describe the softening behavior of material based on tensile experiments. The relative parameters are obtained by fitting the equation with the experimental data. The genetic algorithm has been used to obtain the global optimal fitting parameters. The comparison between the fitted and experimental data proves the effectiveness of the model. The results indicate that this model leads to a better simulation of the flow stress during the softening stage than that of the power law equation. Based on this model, the deep drawing process has been simulated with the commercial finite element code FORGE®. The punch load and thickness distribution of AZ31 sheet have been studied. The study of the results is helpful to the application of the stamping technology for the magnesium alloy sheet.

  20. Superplastic Response of Continuously Cast AZ31B Magnesium Sheet Alloys

    NASA Astrophysics Data System (ADS)

    Boileau, J. M.; Friedman, P. A.; Houston, D. Q.; Luckey, S. G.

    2010-06-01

    Magnesium sheet is typically produced for commercial applications with the traditional DC-ingot casting method. As a result of the hexagonal close-packed crystallographic structure in magnesium, multiple rolling passes and annealing steps are required to reduce the thickness of the ingots. Thus, high fabrication costs characterize the creation of magnesium sheet suitable for common forming operations. Recently, continuous casting (CC) technology, where molten metal is solidified directly into sheet form, has been applied to magnesium alloys; this method has shown the potential to significantly reduce the cost of fabricating magnesium sheet alloys. In order to understand the viability of the CC process, a study was conducted to investigate the superplastic potential of alloys produced by this method. This study focused on AZ31B Mg that was continuously-cast on twin-roll casters from three different suppliers. These three materials were compared with a production DC-cast AZ31B alloy in terms of microstructure, elevated-temperature tensile properties, and superplastic forming response. The data from this study found that microstructural features such as grain size and segregation can significantly affect the forming response. Additionally, the CC alloys can have equivalent or superior SPF response compared to DC-cast alloys, as demonstrated in both elevated temperature tensile tests and superplastic forming trials using a rectangular pan die.

  1. Microstructure control during twin roll casting of an AZ31 magnesium alloy

    NASA Astrophysics Data System (ADS)

    Huang, Y.; Bayandorian, I.; Fan, Z.

    2012-01-01

    The existing twin roll casting technique for magnesium alloys suffers heterogeneity in both microstructure and chemistry and downstream processing is required to improve the strip quality, resulting in cost rise. In the present work, twin roll casting was carried out using an AZ31 magnesium alloy, with the application of intensive shearing melt conditioning prior to casting. The effect of process parameters such as pouring temperature and casting speed on microstructure control during casting and subsequent downstream processing was studied. Experimental results showed that the melt conditioning treatment allowed the production of AZ31 strips with uniform and refined microstructure free of centreline segregations. It was also shown that an optimized combination of pouring temperature and casting speed, in conjunction with a strip thickness control operation, resulted in uniformly distributed stored energies due to enhanced plastic deformation, which promoted recrystallization during casting and subsequent heat treatment. Strips prepared by twin roll casting and homogenization developed similar microstructural features to those prepared by twin roll casting followed by lengthy downstream processing by homogenization, hot rolling and annealing and displayed a weaker basal texture, exhibiting a potentially better formability.

  2. Functional design criteria: Tank 101-AZ waste retrieval system. Revision 3

    SciTech Connect

    Manthei, M.E.

    1995-07-01

    Presented is the functional design criteria for equipment and subsystems required to test the mobilization of sludge in anticipation of retrieval of waste slurry from tank 241-AZ-101. The system utilizes jet forces from two high capacity pumps (mixer pumps) which recirculate liquid within the tank to mobilize the sludge and disperse it in the supernate and produce a slurry suitable for feed to the pretreatment process. This project provides the systems and equipment to prepare Tank AZ-101 for a functional test to verify sludge mobilization capabilities with use of mixer pumps. A retrieval functional test will be conducted by others (not part of the project) to confirm laboratory studies of waste mobilization characteristics and design parameters, to provide basis for system optimization for mobilization of other wastes, and to provide final verification of the effects of the retrieval process on wastes, and to provide final verification of the effects of the retrieval process on other tank farm operational parameters. No waste will be transferred from the tank during the FT. Prior to the test, some existing in-tank components must be removed and disposed of, and replaced with components with increased structural strength and rigidity. Special instrumentation will be provided to measure the effectiveness of the mixer pumps for sludge mobilization. Designing and providing equipment for component removal, handling, and solid waste disposal is a significant part of the project work scope

  3. Microstructural and textural evolution of AZ61 magnesium alloy sheet during bidirectional cyclic bending

    SciTech Connect

    Huo, Qinghuan; Yang, Xuyue, E-mail: yangxuyue@mail.csu.edu.cn; Ma, Jijun; Sun, Huan; Qin, Jia; Jiang, Yupei

    2013-05-15

    In this work, the microstructural and textural evolution in the sheets of AZ61 magnesium alloy was studied by means of bidirectional cyclic bending for 8 passes at 623 K. The bended samples were examined by optical microscopy and electron backscatter diffraction analysis. The results showed that a gradient structure with fine grains about 3 ?m in the regions near two surfaces and, in contrast, coarse grains in the middle of the sheet were formed. The evident grain refinement was attributed to twin-assisted dynamic recrystallization and continuous dynamic recrystallization induced by kink bands. The texture intensity was clearly reduced, resulting in a negative gradient distribution, with the texture intensity decreases from the center of the sheet to two surfaces. The weakened texture greatly facilitated the reduction of the yield strength. A higher fracture elongation and a slightly improved ultimate tensile strength were achieved concurrently. - Highlights: • The AZ61 Mg alloy is deformed at 623 K by bidirectional cyclic bending. • A symmetric gradient distribution of fine grains along the thickness is formed. • The basal texture in the regions near two surfaces is weakened significantly.

  4. SAFETY ANALYSIS FOR TANK 241-AZ-101 MIXER PUMP PROCESS TEST

    SciTech Connect

    HAMMOND DM; HARRIS JP; MOUETTE P

    1997-06-09

    This document contains the completed safety analysis which establishes the safety envelope for performing the mixer pump process test in Tank 241-AZ-101. This process test is described in TF-210-OTP-001. All equipment necessary for the mixer pump test has been installed by Project W-151. The purpose of this document is to describe and analyze the mixer pump test for Aging Waste Facility (AWF) Tank 241-AZ-101 and to address the 'yes/maybe' responses marked for evaluation questions identified in Unreviewed Safety Question Evaluation (USQE) TF-94-0266. The scope of this document is limited to the performance of the mixer pump test for Tank 241-AZ-101. Unreviewed Safety Question Determination (USQD) TF-96-0018 verified that the installation of two mixer pumps into Tank 241-AZ-101 was within the current Tank Waste Remediation System (TWRS) Authorization Basis. USQDs TF-96-0461, TF-96-0448, and TF-96-0805 verified that the installation of the in-tank video camera, thermocouples, and Ultrasonic Interface Level Analyzer (URSILLA), respectively, were within the current TWRS Authorization Basis. USQD TF-96-1041 verified that the checkout testing of the installed equipment was within the current TWRS Authorization Basis. Installation of the pumps and equipment has been completed. An evaluation of safety considerations associated with operation of the mixer pumps for the mixer pump test is provided in this document. This document augments the existing AWF authorization basis as defined in the Interim Safety Basis (Stahl 1997), and as such, will use the existing Interim Operational Safety Requirements (IOSRs) of Heubach 1996 to adequately control the mixer pump test. The hazard and accident analysis is limited to the scope and impact of the mixer pump test, and therefore does not address hazards already addressed by the current AWF authorization basis. This document does not evaluate removal of the mixer pumps. Safety considerations for removal of the pumps will be addressed by separate safety documentation once that portion of the mission is defined. The mixer pump test has been evaluated to cover the use of either the existing ventilation system (241-A-702) or the ventilation system upgrade provided by Project W-030. Analysis of Project W-030 is outside of the scope of this document and is addressed in HNF-SD-WM-SARR-039 (Draft) which, should the W-030 system be in service at the time of the mixer pump test, will have been approved and made a part of the TWRS authorization basis. The test will use two high-capacity mixer pumps in various configurations and modes to demonstrate solids mobilization of waste in Tank 241-AZ-101. The information and experience gained during the test will provide data for comparison with sludge mobilization prediction models; provide data to estimate the number, location, and cycle times of the mixer pumps; and provide indication of the effects of mixer pump operation on the AWF tank systems and components. The slurry produced will be evaluated for future pretreatment processing. This process test does not transfer waste from the tank; the waste is mixed and confined within the existing system. At the completion of the mixer pump test, the mixer pumps will be stopped and normal tank operations, maintenance, and surveillance will continue. Periodic rotation of the mixer pumps and motor shafts, along with bearing greasing, is required to maintain the pumps following the mixer pump test.

  5. Antibiotic Attack (Kinetic City)

    NSDL National Science Digital Library

    American Association for the Advancement of Science (; )

    2005-01-01

    This game is a part of the Tau Pack of the Kinetic City site (see description below). In this simulation, the patient's bodies are filled with bacteria. The object is to cure as many patients as possible. Learning concepts enforced here are that antibiotics are specific for the type of bacteria they treat, their strength, and that the bacteria may also become resistant to the bacteria by mutations.KINETIC CITY DESCRIPTION: "Kinetic City" (www.kineticcity.com) is a fun, Web-based after-school science club for kids, ages 8 through 11. It combines exciting online animations and activities with boxes of hands-on science experiments. Children earn "Kinetic City" power points and collect stickers as they complete missions and learn standards-based science content. Here's how it works: The "Kinetic City" super crew (Keisha, Curtis, Megan and Max) needs the help of Earth kids to save their planet Vearth, from the science-distorting computer virus Deep Delete. Each of Deep Delete's 60 hideous strains attacks a different area of science with disastrous consequences. After each attack, teams of Earth kids fight back by viewing a short online animation describing the situation on Vearth; performing a series of activities to re-learn the lost science and going on a mission to Vearth during which they answer science questions and gobble up Deep Delete viruses. Their scores appear on their own Kinetic City Club Web page. "Kinetic City" is produced by the American Association for the Advancement of Science (AAAS), with a grant from the National Science Foundation. AAAS writes the "Project 2061 Benchmarks for Science Literacy," which forms the basis of most state science standards.

  6. Low dose of the liver X receptor agonist, AZ876, reduces atherosclerosis in APOE*3Leiden mice without affecting liver or plasma triglyceride levels

    PubMed Central

    van der Hoorn, JWA; Lindén, D; Lindahl, U; Bekkers, MEA; Voskuilen, M; Nilsson, R; Oscarsson, J; Lindstedt, EL; Princen, HMG

    2011-01-01

    BACKGROUND AND PURPOSE Liver X receptor (LXR) agonists are atheroprotective but often induce hypertriglyceridaemia and liver steatosis. We investigated the effect of a novel high-affinity LXR activator, AZ876, on plasma lipids, inflammation and atherosclerosis, and compared the effects with another LXR agonist, GW3965. EXPERIMENTAL APPROACH APOE*3Leiden mice were fed an atherogenic diet alone or supplemented with either AZ876 (5 or 20 µmol·kg?1·day?1) or GW3965 (17 µmol·kg?1·day?1) for 20 weeks. Total cholesterol and triglyceride levels were measured using commercial kits. Plasma cytokines were determined by using bead-based multiplex suspension array kits with the Luminex technology. Atherosclerosis was assessed histochemically and lesion composition was assessed by immunohistochemical methods. KEY RESULTS Low-dose AZ876 had no effect on plasma or liver lipids, whereas high-dose AZ876 increased plasma triglycerides (+110%) and reduced cholesterol (?16%) compared with controls. GW3965 increased plasma triglycerides (+70%). Low-dose AZ876 reduced lesion area (?47%); and high-dose AZ876 strongly decreased lesion area (?91%), lesion number (?59%) and severity. In either dose, AZ876 did not affect lesion composition. GW3965 reduced atherosclerosis and collagen content of lesions (?23%; P < 0.01). High-dose AZ876 and GW3965, but not low-dose AZ876, reduced inflammation as reflected by lower cytokine levels and vessel wall activation. CONCLUSIONS AND IMPLICATIONS We have identified a novel LXR agonist that when given in a low dose inhibits the progression of atherosclerosis without inducing anti-inflammatory effects, liver steatosis or hypertriglyceridaemia. Therefore, the primary protective action of a low-dose AZ876 is likely to be an increased reverse cholesterol transport. PMID:21175581

  7. Earth's City Lights

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This image of Earth's city lights was created with data from the Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS). Originally designed to view clouds by moonlight, the OLS is also used to map the locations of permanent lights on the Earth's surface. The brightest areas of the Earth are the most urbanized, but not necessarily the most populated. (Compare western Europe with China and India.) Cities tend to grow along coastlines and transportation networks. Even without the underlying map, the outlines of many continents would still be visible. The United States interstate highway system appears as a lattice connecting the brighter dots of city centers. In Russia, the Trans-Siberian railroad is a thin line stretching from Moscow through the center of Asia to Vladivostok. The Nile River, from the Aswan Dam to the Mediterranean Sea, is another bright thread through an otherwise dark region. Even more than 100 years after the invention of the electric light, some regions remain thinly populated and unlit. Antarctica is entirely dark. The interior jungles of Africa and South America are mostly dark, but lights are beginning to appear there. Deserts in Africa, Arabia, Australia, Mongolia, and the United States are poorly lit as well (except along the coast), along with the boreal forests of Canada and Russia, and the great mountains of the Himalaya. The Earth Observatory article Bright Lights, Big City describes how NASA scientists use city light data to map urbanization. Image by Craig Mayhew and Robert Simmon, NASA GSFC, based on DMSP data

  8. 76 FR 81525 - Notice of Realty Action: Conveyance of Federally Owned Mineral Interests in Pinal County, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-28

    ...Action: Conveyance of Federally Owned Mineral Interests in Pinal County, AZ AGENCY...the conveyance of the federally owned mineral interests of a 459.60 acre tract of...notice temporarily segregates the Federal mineral interests in the land covered by the...

  9. WM '04 Conference, February 29 March 4, 2004, Tucson, AZ WM-4010 VITRIFICATION OF LOW AND INTERMEDIATE LEVEL WASTE: TECHNOLOGY

    E-print Network

    Sheffield, University of

    -fed Joule heated ceramic melters (JHCM) were used later replaced by cold crucible high frequency induction since the 1970s. The current cold crucible high frequency induction melters (CCM) are used to vitrify melters (CCM). #12;WM '04 Conference, February 29 ­ March 4, 2004, Tucson, AZ WM-4010 JOULE HEATED CERAMIC

  10. ARSENIC REMOVAL FROM DRINKING WATER BY ADSORPTIVE MEDIA. USEPA DEMONSTRATION PROJECT AT VALLEY VISTA, AZ FINAL PERFORMANCE EVALUATION REPORT

    EPA Science Inventory

    This report documents the activities performed during and the results obtained from the arsenic removal treatment technology demonstration project at an Arizona Water Company (AWC) facility in Sedona, AZ, commonly referred to as Valley Vista. The objectives of the project were t...

  11. 75 FR 61660 - Proposed Modification of Class D and E Airspace, and Revocation of Class E Airspace; Flagstaff, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-06

    ...10-AWP-5 Proposed Modification of Class D and E Airspace, and Revocation of Class...SUMMARY: This action proposes to modify Class D and E airspace at Flagstaff, AZ, to accommodate...airspace designated as an extension to a Class D or E surface area at Flagstaff Pulliam...

  12. 75 FR 76924 - Modification of Class D and E Airspace, and Revocation of Class E Airspace; Flagstaff, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-10

    ...No. 10-AWP-5] Modification of Class D and E Airspace, and Revocation of Class...SUMMARY: This action will modify Class D and E airspace at Flagstaff, AZ, to accommodate...airspace designated as an extension to a Class D or E surface area at Flagstaff Pulliam...

  13. Directory Home Directory Liaison List Server Help A-Z Index IFAS Main Pa Unit Name: Ft. Lauderdale -REC

    E-print Network

    Florida, University of

    Directory Home Directory Liaison List Server Help A-Z Index IFAS Main Pa Unit Name: Ft. Lauderdale, and Page 1 of 2Employee and Unit Directory - IFAS - Institute of Food and Agricultural Sciences, University of Flor... 8/13/2013http://directory.ifas.ufl.edu/Dir/searchdir?pageID=2&uid=85 #12;Tampa) 1. Take US-27

  14. CIRP Conference on Modeling of Machining Operations (CIRP CMMO) Constitutive Modelling of AZ31B-O Magnesium Alloy

    E-print Network

    Paris-Sud XI, Université de

    B-O Magnesium Alloy for Cryogenic Machining E. Girauda* , F. Rossib , G. Germaina , J.C. Outeirob disks of AZ31B-O magnesium alloy, using a special designed tool. In order to include the effects of Machining Operations" in the person of the Conference Chair Prof. Luca Settineri Keywords: Magnesium alloy

  15. Materials Science and Engineering A 418 (2006) 341356 Microstructural effects of AZ31 magnesium alloy on its

    E-print Network

    Tong, Wei

    Materials Science and Engineering A 418 (2006) 341­356 Microstructural effects of AZ31 magnesium Magnesium alloys exhibit the attractive combination of low densities (1.74 g/cm3 versus 2.7 g/cm3 for Al

  16. Summer cooling efficiency of landscapes in Phoenix, AZ Ariane Middel , Anthony J. Brazel , Shai Kaplan , Soe W. Myint

    E-print Network

    Hall, Sharon J.

    Summer cooling efficiency of landscapes in Phoenix, AZ 1 2 2 2 Ariane Middel , Anthony J. Brazel., Pearlmutter, D., Erell, E., 2009, The cooling efficiency of urban landscape strategies in a hot dry climate and the amount of cooling achieved, we adopted the cooling efficiency index by Shashua-Bar et al. (2009). Cooling

  17. JOURNAL OF MATERIALS SCIENCE LETTERS 20, 2001, 457459 Tensile and fatigue behavior of AZ91D magnesium alloy

    E-print Network

    Zhou, Wei

    and then at 420 C for 24 h in argon atmosphere followed by water quench at 25 C. The solution treated alloy material for coping with energy conservation and environmental pollution regulations. Much of the recent strength magne- sium alloys. AZ91D alloy was subjected to solution heat- treatment at 380 C for 8 h

  18. Histone H2A.Z controls a critical chromatin remodeling step required for DNA double-strand break repair.

    PubMed

    Xu, Ye; Ayrapetov, Marina K; Xu, Chang; Gursoy-Yuzugullu, Ozge; Hu, Yiduo; Price, Brendan D

    2012-12-14

    Chromatin remodeling during DNA double-strand break (DSB) repair is required to facilitate access to and repair of DSBs. This remodeling requires increased acetylation of histones and a shift in nucleosome organization to create open, relaxed chromatin domains. However, the underlying mechanism driving changes in nucleosome structure at DSBs is poorly defined. Here, we demonstrate that histone H2A.Z is exchanged onto nucleosomes at DSBs by the p400 remodeling ATPase. H2A.Z exchange at DSBs shifts the chromatin to an open conformation and is required for acetylation and ubiquitination of histones and for loading of the brca1 complex. H2A.Z exchange also restricts single-stranded DNA production by nucleases and is required for loading of the Ku70/Ku80 DSB repair protein. H2A.Z exchange therefore promotes specific patterns of histone modification and reorganization of the chromatin architecture, leading to the assembly of a chromatin template that is an efficient substrate for the DSB repair machinery. PMID:23122415

  19. Warm Deep Drawing of Rectangular Parts of AZ31 Magnesium Alloy Sheet Adopting Variable Blank Holder Force

    SciTech Connect

    Peng Yinghong; Chang Qunfeng; Li Dayong [School of Mechanical Engineering, Shanghai Jiaotong University, 200240 (China); Zeng Xiaoqin [School of Materials Science and Engineering, Shanghai Jiaotong University, Shanghai 200240 (China)

    2007-05-17

    AZ31 magnesium alloy sheet with good shape and formability is fabricated by warm cross rolling. Uniaxial tensile tests are conducted using a Gleeble 3500 thermal - mechanical simulator, and the mechanical properties of AZ31 magnesium alloy sheet are analyzed. A warm deep drawing process of square part is also simulated by the finite element method. The influences of blank holder force on the formability are numerically investigated. A double-action hydraulic press that can realize adjustable blank holder forces is developed and its working principle and control system are introduced. Some warm deep drawing experiments of square parts of AZ31 magnesium alloy sheet are also performed. Different variation schemes of the blank holder force with the stroke of the punch are tested, and the experiment results are compared. Results show that the suitable blank holder force variation scheme is a ladder curve with the punch stroke. Adopting the variable blank holder force technique can improve 13.2% of the drawing depth of square parts of AZ31 magnesium alloy sheet.

  20. COUNTRY INSTITUTION DATE WEB ADDRESS AZERBAIJAN Azerbaijan Medical University 15.03.2011 http://amu.edu.az/

    E-print Network

    Di Pillo, Gianni

    and Construction 16.12.2011 http://www.azmiu.edu.az IRAN Institute of Higher Education of Alaodoleh Semnani 03 Sciences 02.04.2007 http://www.sums.ac.ir IRAN Higher Education Institute - Sooreh - Tehrn Branch 04://www.usek.edu.lb #12;PALESTINE (PALESTINIAN TERRITORIES) An-Najah National University 21.03.2006 http

  1. Annual Report 2009 -2010 Department of Mathematics, Tucson, AZ 85721 520.626.6145 ime.math.arizona.edu

    E-print Network

    Zakharov, Vladimir

    Annual Report 2009 - 2010 Department of Mathematics, Tucson, AZ 85721 · 520.626.6145 · ime activities. If you are interested in supporting the work of the Institute, please visit ime Partnership grant (award no. 0634532) awarded to the IM&E in September of 2006. The Principal Investigator

  2. Arsenic Removal from Drinking Water by Adsorptive Media USEPA Demonstration Project at Rimrock AZ Final Performance Evaluation Report

    EPA Science Inventory

    This report documents the activities performed during and the results obtained from the arsenic removal treatment technology demonstration project at the Arizona Water Company (AWC) facility in Rimrock, AZ. The objectives of the project were to evaluate: 1) the effectiveness of ...

  3. ARSENIC REMOVAL FROM DRINKING WATER BY ADSORPTIVE MEDIA, USEPA DEMONSTRATION PROJECT AT RIMROCK, AZ, SIX-MONTH EVALUATION REPORT

    EPA Science Inventory

    This report documents the activities performed during and the results obtained from the first six months of the arsenic removal treatment technology demonstration project at Rimrock, AZ. The objectives of the project are to evaluate the effectiveness of AdEdge Arsenic Package Uni...

  4. In Proceedings of the 1999 Winter Simulation Conference, Phoenix, AZ. BPR AND LOGISTICS: THE ROLE OF COMPUTATIONAL MODELS

    E-print Network

    In Proceedings of the 1999 Winter Simulation Conference, Phoenix, AZ. BPR AND LOGISTICS: THE ROLE- gistics, and the cost of logistics is roughly 10% of GDP in the US. Designing, managing, and improving indus- trial logistics systems has never been more challenging, or more critical to competitive success

  5. Impacts of weather variability on turbulent heat fluxes in Phoenix, AZ and Portland, OR 1 2 12 2 3 3

    E-print Network

    Hall, Sharon J.

    the partitioning of net all-wave radiation into sensible and latent heat fluxes as well as heat storageImpacts of weather variability on turbulent heat fluxes in Phoenix, AZ and Portland, OR 1 2 12 2 3 Meteorology 41: 792-810. rimmond CSB, Oke TR. 2002. Turbulent heat fluxes in urban areas: observations

  6. ARSENIC REMOVAL FROM DRINKING WATER BY ADSORPTIVE MEDIA USEPA DEMONSTRATION PROJECT AT VALLEY VISTA, AZ SIX-MONTH EVALUATION REPORT

    EPA Science Inventory

    This report documents the activities performed and the results obtained from the first six months of the EPA arsenic removal technology demonstration project at the Arizona Water Company (AWC) facility in Sedona, AZ, commonly referred to as Valley Vista. The main objective of the...

  7. Effect of TiN nano-coating on the interface microstructure of carbon fibres-AZ91 alloy composite

    NASA Astrophysics Data System (ADS)

    Olszówka-Myalska, A.; Botor-Probierz, A.

    2012-03-01

    Magnesium matrix composites reinforced with carbon fibres, Cf, without surface modification and coated with TiN nanolayer, (Cf)TiN, were investigated. AZ91 magnesium alloy and carbon fibres of T300B (Toray) PAN type were chosen as components. In the experiment infiltration in vacuum as a method of component consolidation and chemical vapour deposition (CVD) for carbon fibres surface modification were applied. Structural investigations were performed in the Hitachi 3200S field-emission scanning electron microscope (FE-SEM) and on a FEI Tecnai G2 FEG high-resolution transmission electron microscope (TEM) equipped with energy-dispersive X-ray spectrometer (EDS) and high angle annular dark field (HAADF) detectors. SEM observations revealed that at the interface of AZ91-Cf composite destructive phases were formed. An application of TiN nano-coating as a surface modification ensured proper wettability of carbon fibres by liquid metal and protection against the destructive products formation. The microstructure of AZ91-(Cf)TiN composite interface was multilayered. TEM investigation revealed a continuous layer of mixed alumina and magnesia just at the carbon surface, followed by a layer with a dominant concentration of titanium, enriched with Al, O, Mg and C and subsequently a layer of nano-sized Al12Mg17 crystals in the magnesium matrix. Therefore, an applied TiN nano-coating can be classified as an active barrier in AZ91-Cf system.

  8. Pump Jet Mixing and Pipeline Transfer Assessment for High-Activity Radioactive Wastes in Hanford Tank 241-AZ-102

    SciTech Connect

    Y Onishi; KP Recknagle; BE Wells

    2000-08-09

    The authors evaluated how well two 300-hp mixer pumps would mix solid and liquid radioactive wastes stored in Hanford double-shell Tank 241-AZ-102 (AZ-102) and confirmed the adequacy of a three-inch (7.6-cm) pipeline system to transfer the resulting mixed waste slurry to the AP Tank Farm and a planned waste treatment (vitrification) plant on the Hanford Site. Tank AZ-102 contains 854,000 gallons (3,230 m{sup 3}) of supernatant liquid and 95,000 gallons (360 m{sup 3}) of sludge made up of aging waste (or neutralized current acid waste). The study comprises three assessments: waste chemistry, pump jet mixing, and pipeline transfer. The waste chemical modeling assessment indicates that the sludge, consisting of the solids and interstitial solution, and the supernatant liquid are basically in an equilibrium condition. Thus, pump jet mixing would not cause much solids precipitation and dissolution, only 1.5% or less of the total AZ-102 sludge. The pump jet mixing modeling indicates that two 300-hp mixer pumps would mobilize up to about 23 ft (7.0 m) of the sludge nearest the pump but would not erode the waste within seven inches (0.18 m) of the tank bottom. This results in about half of the sludge being uniformly mixed in the tank and the other half being unmixed (not eroded) at the tank bottom.

  9. Microstructure, mechanical properties and texture evolution of AZ31 alloy containing trace levels of strontium

    SciTech Connect

    Sadeghi, Alireza, E-mail: alireza.sadeghi@mail.mcgill.ca; Pekguleryuz, Mihriban

    2011-08-15

    The effect of low levels of Sr (0.01, 0.03, 0.05 wt.%) on the microstructure, mechanical properties and texture of AZ31 magnesium alloy has been investigated. Thermodynamic modeling has been used to study the effect of Sr on phase precipitation at different temperatures. Cooling curve analysis reveals a decrease in solidification superheat with the addition of 0.03 wt.% Sr to AZ31. The as-cast microstructures of the alloys have been studied using optical microscopy (OM) and electron probe micro analysis (EPMA). Results show the refining effect of Sr on the grain size and on the {beta}-Mg{sub 17}Al{sub 12} precipitates through growth poisoning and inoculation, respectively. To investigate the mechanical properties of the alloys, as-cast samples were compression tested at elevated temperatures. Hot compression peak stress ({sigma}{sub max}) and critical strain before recrystallization ({epsilon}{sub c}) initially drop but then increase. {sigma}{sub max} first decreases due to the depletion of Al from solid solution and then increases when the amount of the Al-Sr precipitates reach a significant amount. {epsilon}{sub c} drops due to the acceleration of dynamic recrystallization kinetics as a result of grain refinement. It increases with increasing Sr when the concentration Sr in solid solution is increased leading to dislocation pinning and retardation of recrystallization. X-ray texture measurements on the hot compressed and extruded samples show a decrease in maximum intensity of the basal pole figures with increasing Sr as a result of reduced twining and the changes in Al and Sr concentrations in solid solution. - Research Highlights: {yields} Microstructures/precipitates of AZ31+trace levels of Sr were examined by OM and EPMA. {yields} Thermodynamic calculations and cooling curve analysis were used to predict ppt formation. {yields} It has been shown that Sr refines the grains and Mg17Al12 precipitates. {yields} Mechanical properties and texture were studied using hot compression and X-ray diffraction. {yields} Different micro-mechanisms were responsible for mechanical and texture changes.

  10. AZ-101 Mixer Pump Demonstration and Tests Data Management Analysis Plan

    SciTech Connect

    DOUGLAS, D.G.

    2000-02-22

    This document provides a plan for the analysis of the data collected during the AZ-101 Mixer Pump Demonstration and Tests. This document was prepared after a review of the AZ-101 Mixer Pump Test Plan (Revision 4) [1] and other materials. The plan emphasizes a structured and well-ordered approach towards handling and examining the data. This plan presumes that the data will be collected and organized into a unified body of data, well annotated and bearing the date and time of each record. The analysis of this data will follow a methodical series of steps that are focused on well-defined objectives. Section 2 of this plan describes how the data analysis will proceed from the real-time monitoring of some of the key sensor data to the final analysis of the three-dimensional distribution of suspended solids. This section also identifies the various sensors or sensor systems and associates them with the various functions they serve during the test program. Section 3 provides an overview of the objectives of the AZ-101 test program and describes the data that will be analyzed to support that test. The objectives are: (1) to demonstrate that the mixer pumps can be operated within the operating requirements; (2) to demonstrate that the mixer pumps can mobilize the sludge in sufficient quantities to provide feed to the private contractor facility, and (3) to determine if the in-tank instrumentation is sufficient to monitor sludge mobilization and mixer pump operation. Section 3 also describes the interim analysis that organizes the data during the test, so the analysis can be more readily accomplished. Section 4 describes the spatial orientation of the various sensors in the tank. This section is useful in visualizing the relationship of the Sensors in terms of their location in the tank and how the data from these sensors may be related to the data from other sensors. Section 5 provides a summary of the various analyses that will be performed on the data during the test program. Finally, an appendix reviews the technical aspects of the key sensor systems that will be used in the program. This review focuses on the performance capabilities and limits of the sensing systems.

  11. Cities Around the World

    NSDL National Science Digital Library

    From Carthage to Chicago, this fascinating digital collection from the University of Wisconsin-Milwaukee presents quite a cornucopia of photographic images drawn from the world's cities, past and present. The images are from the American Geographic Society Library, and just two photographers, Harrison Forman and the noted urban geographer, Harold Mayer, took the pictures. All told, there are over 5500 photographic images in this collection, and first-time visitors should read over the brief introductory essays on the scope and content of this project before jumping into the materials. By clicking on the "Cities" section, visitors can browse around the cities with the most photographs, and then they may also wish to perform a detailed search. There are some fun surprises here, including an aerial view of the Union Stock Yards in Chicago and the governor's residence in Dar es Salaam.

  12. 100 Resilient Cities

    NSDL National Science Digital Library

    The future of cities is the subject of much hand-wringing in urban policy circles. As of late, a popular topic has been the concept of urban "resilience" and the Rockefeller Foundation has taken this matter on with its 100 Resilient Cities initiative. On its website, first-time visitors should first explore the "What is Resilience?" area. Here, the topic is explained in detail and an infographic links to a number of helpful resources. Moving on, visitors can explore the foundation's blog and some of the Most Read entries, such as "The Five Fastest Growing Cities" and "Slumdog Urbanism." Each entry features a comments section that allows visitors to chime in with their own thoughts on resilience in the 21st century. The site is rounded out with a nice subscription feature, allowing readers the opportunity to receive email updates once new material is published on the site.

  13. The Atlantic Cities

    NSDL National Science Digital Library

    2013-09-23

    What will the future of cities be like? It's a riveting question and one that excites the passions of the folks at The Atlantic Cities website. Their work here "explores the most innovative ideas and pressing issues facing today's global cities and neighborhoods." Visitors should browse through their newest articles, which might include "Why Our Kids Need Play" and "How Poverty Taxes the Brain." The site also has some neat features, including the Charts, Photos, and Urban Wonk areas. Geographers and artists will love the Maps section, which includes both scholarly and humorous offerings. First-time visitors should pay special attention here to "A Block-by-Block Map of Brooklyn, in Garbage" and "One Map, A World of Temperatures." Additionally, visitors can also sign up to receive their e-newsletter and other updates, including information about upcoming conferences and lectures sponsored by The Atlantic.

  14. The Guardian Cities

    NSDL National Science Digital Library

    The Guardian newspaper has crafted this wonderful site to bring curious urbanologists news from Seoul to San Francisco. Supported in part by the Rockefeller Foundation, the site offers "a forum for debate and the sharing of ideas about the future of cities around the world.� Articles on the homepage might include pieces on investment in Detroit by Chinese corporations or the shifting public art scene in Glasgow. New visitors may wish to start with "An urbanist's tour of South Korea,� which features the musings of Colin Marshall on this dynamic Asian country. Moving along, the Global voices section features an interactive map of the best city blogs around the world. The site also contains the visually stimulating In pictures area and the up-to-the-moment Latest on cities newsfeed.

  15. Engineers Week: Future City

    NSDL National Science Digital Library

    The National Engineers Week Future City Competition provides â??a fun and exciting educational engineering program for seventh- and eighth-grade students that combines a stimulating engineering challenge with a â??hands-onâ?? application to present their vision of a city of the future.â? The competition is intended to foster engineering skills, such as teamwork, communication and problem solving skills, as well as to inspire students to explore future careers in engineering. Using the commercial software SIMCITY to design their ideal city, students interact with each other, and with teachers and engineer mentors and also learn about the multi-disciplines within the engineering profession. The website has more information about the competition, as well as a handbook providing helpful tips and techniques. Examples of accomplishments from previous competitions are posted and CD-ROM video is available from regional coordinators to give more background on the competition.

  16. Water in the City

    NSDL National Science Digital Library

    Water in the City is part of the Franklin Institute Science Museum's Science in the City Web site. The activity is described as a way to investigate the most precious natural resource in cities. The resources accumulated and presented on the site are held within several areas that include Water Basics, Water Science, Philadelphia Water Ways, Worldwide Water Ways, and References and Activities. The water basics page, for example, contains a glossary of water terminology; water trivia; and information on water myths and realities, dams, water power, conserving water, and keeping water clean. Although most resources are from outside sources, the site does a good job of explaining the concepts and providing kids with a single spot to explore other sites with information on this specific subject.

  17. Cities and Buildings Database

    NSDL National Science Digital Library

    The University of Washington Libraries Digital Collection online projects and archives are well-regarded, and this database proves to be no exception to that highly positive trend. Started in 1995, the Cities and Buildings Database contains over 10,000 digitized images of buildings and cities culled from all historical periods and from all over the world. Visitors may wish to start with a simple keyword search or if they are interested in merely browsing by country, they may do so as well from the homepage. Of course, one should not be surprised to also learn that visitors may also perform detailed searches for buildings by city, style, title, architect, and date of construction. Just to give prospective visitors some sense of the depth and breadth of the collection, the database contains everything from conceptual sketches of Frank Gehry's Experience Music Project to photographs of the monastery of St. Keghard in Armenia.

  18. State of the Cities

    NSDL National Science Digital Library

    2000-01-01

    The report finds that while "the booming national economy and the growth of high-tech jobs have helped reverse decades of decline in America's cities," the "digital divide" continues to make itself felt as the number of high-tech jobs is growing 30 percent faster in the suburbs than urban areas. In addition, housing prices have risen at twice the rate of inflation, worsening an affordable housing shortage. See also the New Data section in this report for a review of the State of the Cities Data System, 2000.

  19. Cytotoxicity studies of AZ31D alloy and the effects of carbon dioxide on its biodegradation behavior in vitro.

    PubMed

    Wang, Jiali; Qin, Ling; Wang, Kai; Wang, Jue; Yue, Ye; Li, Yangde; Tang, Jian; Li, Weirong

    2013-10-01

    Magnesium alloys have been advocated as potential artificial bone materials due to their biocompatibility and biodegradability. The understanding of their corrosive mechanism in physiological environments is therefore essential for making application-orientated designs. Thus, this in vitro study was designed to assess the effects of CO2 on corrosive behavior of AZ31D to mimic in vivo special ingredient. Electrochemical technologies accompanied with Scanning electron microscope, Fourier transform infrared, X-ray diffraction, Energy dispersive spectroscopy and hydrogen evolution measurement were employed to analyze corrosive rates and mechanisms of AZ31D. Moreover, the biocompatibility of AZ31D was assessed with a direct cell attachment assay and an indirect cytotoxicity test in different diluted extracts. The ion concentrations in extracts were measured using inductively coupled plasma mass spectrometry to offer explanations on the differences of cell viability in the indirect test. The results of the direct cytotoxicity assay showed that the corrosive rate of AZ31D was too rapid to allow for cell adhesion. Extracts diluted less than 20 times would cause adverse effects on cell proliferation, likely due to excessive ions and gas release. Moreover, the presence of CO2 did not cause significant differences on corrosive behavior of AZ31D according to the results of electrochemical testing and hydrogen evolution measurement. This might be caused by the simultaneous process of precipitation and dissolution of MgCO3 due to the penetration role of CO2. This analysis of corrosive atmospheres on the degradation behavior of magnesium alloys would contribute to the design of more scientific in vitro testing systems in the future. PMID:23910361

  20. Spectral properties of the extreme solar system objects 2012 DR30 and 2013 AZ60

    NASA Astrophysics Data System (ADS)

    Szabo, G.; Kiss, Cs.; Duffard, R.; Pinilla-Alonso, N.; Licandro, J.

    2014-04-01

    2012 DR30 and 2013 AZ60 represent two examples of TNOs with very large aphelion distances (2405 and 1951 AU, respectively), thus standing for the currently best candidates of possible scattered-in Oort-cloud objects. Though they possibly shared a similar dynamical scenario, the two bodies exhibit surprisingly diverging prediction for orbital evolution and also quite different surface properties (Kiss et al. 2013, Kiss et al. 2014). Here we compare these optical and infrared photometry and spectra of the two bodies. Both show a generaly flat spectrum, but with significantly differing slope. We find clear signs of water ice on 2013 DR30 particulary, which is an exciting diagnostic of a possible water reservoir at very large perihelion distances, and on the other hand, suggests a close link between the giant cometary nuclei of the Oort Cloud (for that Hale-Bopp is the only known example in our Solar System) and these exotic TNOs.

  1. Formation of Ha-Containing Coating on AZ31 Magnesium Alloy by Micro-Arc Oxidation

    NASA Astrophysics Data System (ADS)

    Tang, Hui; Li, Deyu; Chen, Xiuping; Wu, Chao; Wang, Fuping

    2013-08-01

    Magnesium and its alloys are potential biodegradable implant materials due to their attractive biological properties. But the use of magnesium is still hampered by its poor corrosion resistance in physiological fluids. In this study, a HA-containing coating was fabricated by micro-arc oxidation (MAO). The active plasma species of micro-discharge was studied by optical emission spectroscopy (OES). The microstructure and composition were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The corrosion behavior and apatite-forming ability were studied by electrochemical tests and immersed samples in simulated body fluids (SBF). The results show that the microdischarge channel model is gas discharges and oxide layer discharges. The elements from the substrate and electrolyte take part in the formation of the coating. The MAO coating significantly improves the corrosion resistance of AZ31 magnesium alloy and enhances the apatite formation ability.

  2. Statistical analysis on static recrystallization texture evolution in cold-rolled AZ31 magnesium alloy sheet.

    PubMed

    Park, Jun-Ho; Ahn, Tae-Hong; Choi, Hyun-Sik; Chung, Jung-Man; Kim, Dong-Ik; Oh, Kyu Hwan; Han, Heung Nam

    2013-08-01

    Cast AZ31B-H24 magnesium alloy, comprising Mg with 3.27 wt% Al and 0.96 wt% Zn, was cold rolled and subsequently annealed. Global texture evolutions in the specimens were observed by X-ray diffractometry after the thermomechanical processing. Image-based microstructure and texture for the deformed, recrystallized, and grown grains were observed by electron backscattered diffractometry. Recrystallized grains could be distinguished from deformed ones by analyzing grain orientation spread. Split basal texture of ca. ±10-15° in the rolling direction was observed in the cold-rolled sample. Recrystallized grains had widely spread basal poles at nucleation stage; strong {0001} basal texture developed with grain growth during annealing. PMID:23920167

  3. Simulation of cylindrical cup drawing of AZ31 sheet metal with crystal plasticity finite element method

    NASA Astrophysics Data System (ADS)

    Tang, Weiqin; Li, Dayong; Zhang, Shaorui; Peng, Yinghong

    2013-12-01

    As a light-weight structural material, magnesium alloys show good potential in improving the fuel efficiency of vehicles and reducing CO2 emissions. However, it is well known that polycrystalline Mg alloys develop pronounced crystallographic texture and plastic anisotropy during rolling, which leads to earing phenomenon during deep drawing of the rolled sheets. It is vital to predict this phenomenon accurately for application of magnesium sheet metals. In the present study, a crystal plasticity model for AZ31 magnesium alloy that incorporates both slip and twinning is established. Then the crystal plasticity model is implemented in the commercial finite element software ABAQUS/Explicit through secondary development interface (VUMAT). Finally, the stamping process of a cylindrical cup is simulated using the developed crystal plasticity finite element model, and the predicting method is verified by comparing with experimental results from both earing profile and deformation texture.

  4. Effect of heat treatments on oxidation kinetics in AZ91 and AM60 magnesium alloys

    SciTech Connect

    Barrena, M.I., E-mail: ibarrena@quim.ucm.es; Gomez de Salazar, J.M.; Matesanz, L.; Soria, A.

    2011-10-15

    The effect of heat treatments on a non protective atmosphere (air) on the morphology and composition of the oxide in AM60 and AZ91 alloys has been evaluated. With the aim of evaluating the loss of alloying elements during heat treatment, a study of these alloys has been carried out using thermogravimetric analysis (TGA). In order to determine the nature of the oxides the reaction products generated were evaluated by scanning electron microscopy and X-ray diffraction. Results show that the nature and morphology of the oxides generated are related to the temperature and the time of the heating conditions applied. - Highlights: {yields} The effect of heat treatments on the oxide growth in Mg-Al alloys has been evaluated. {yields} The nature and morphology of the oxides have been characterized. {yields} These oxides are associated to the time and the temperature conditions.

  5. Laser Cladding of Magnesium Alloy AZ91D with Silicon Carbide

    NASA Astrophysics Data System (ADS)

    Cai, L. F.; Mark, C. K.; Zhou, Wei

    Mg alloys are ultralight but their structural applications are often limited by their poor wear and corrosion resistance. The research aimed to address the problem by laser-cladding. Cladding with SiC powder onto surface of AZ91D was carried out using Nd:YAG laser. The laser-clad surface was analyzed using the optical microscope, SEM equipped with EDS, and XRD and found to contain SiC and other Si compounds such as Mg2Si and Al3.21Si0.47 as well as much refined ?-Mg grains and ?-Mg17Al12 intermetallics. The laser-clad surface possesses considerably higher hardness but its corrosion resistance is not improved, indicating that the laser-cladding technique can only be adopted for applications in noncorrosive environments where wear is the predominant problem.

  6. Tank 241-AZ-101 prototype corrosion probe four month status report

    SciTech Connect

    Edgemon, G.L., Westinghouse Hanford

    1996-12-12

    High-level nuclear wastes at the Hanford Site are stored underground in carbon steel double-shell and single-shell tanks. The installation of a prototype corrosion monitoring system into double-shell tank 241-AZ-101 was completed in August, 1996. The system monitors fluctuations in corrosion current and potential (electrochemical noise) occurring on three electrode arrays immersed in the waste liquid and in the vapor space above the waste. The system also supports the use of Tafel and linear polarization resistance testing. By monitoring and analyzing the data from these techniques, changes in the corrosive characteristics of the waste have been rapidly detected and correlated with operational changes in the tank.

  7. Grain Refinement of AZ31 Magnesium Alloy Weldments by AC Pulsing Technique

    NASA Astrophysics Data System (ADS)

    Kishore Babu, N.; Cross, C. E.

    2012-11-01

    The current study has investigated the influence of alternating current pulsing on the structure and mechanical properties of AZ31 magnesium alloy gas tungsten arc (GTA) weldments. Autogenous full penetration bead-on-plate GTA welds were made under a variety of conditions including variable polarity (VP), variable polarity mixed (VPM), alternating current (AC), and alternating current pulsing (ACPC). AC pulsing resulted in significant refinement of weld metal when compared with the unpulsed conditions. AC pulsing leads to relatively finer and more equiaxed grain structure in GTA welds. In contrast, VP, VPM, and AC welding resulted in predominantly columnar grain structures. The reason for this grain refinement may be attributed to the periodic variations in temperature gradient and solidification rate associated with pulsing as well as weld pool oscillation observed in the ACPC welds. The observed grain refinement was shown to result in an appreciable increase in fusion zone hardness, tensile strength, and ductility.

  8. AZ-101 Mixer Pump Test MT Fury Suspended Solids Profiler Application and Testing

    SciTech Connect

    MACLEAN, G.T.

    2000-01-06

    Describes the radiation testing and calibration of the AZ-101 tank suspended solids profiler unit mounted on 6 tank riser 24A. The Mt. Fury Suspended Solids Profiler (SSP) is a microprocessor-controlled instrument that measures the turbidity of solid-liquid suspensions and sludges. The profiler is used commercially for the monitoring and control of clarifiers and thickeners in waste treatment, mining, pulp and paper, and other industrial processing facilities. The instrument includes a three inch diameter probe, a Kynar coated coaxial cable, a reel assembly with a clutch and drive shaft, a stepper motor, and electronics. The instrument measures insoluble or suspended solids content in liquids by transmitting infrared energy at a wavelength of 935 nm and measuring the extent of backscatter. This frequency is not affected by solution color. There are two detectors that allow the instrument to operate over a broad range of concentrations, from clear liquids to light sludges.

  9. Initiation of fatigue cracks in AZ91 Mg alloy processed by ECAP

    NASA Astrophysics Data System (ADS)

    Fintová, S.; Kunz, L.

    2014-08-01

    Mechanism of fatigue crack initiation was investigated in ultrafine-grained (UFG) magnesium alloy AZ91 processed by equal channel angular pressing (ECAP). Fatigue behaviour of UFG material was compared to the behaviour of material in an initial as-cast state. Focused ion beam technique (FIB) was applied to reveal the surface relief and early fatigue cracks. Two substantially different mechanisms of crack initiation were observed in UFG structure, which can be characterized as bimodal even after 6 ECAP passes by route Bc. The bimodality consists in a coexistence of very fine grained areas with higher content of Mg17Al12 particles and areas exhibiting somewhat larger grains and lower density of particles. The fatigue cracks which initiate in areas of larger grains are related to the cyclic slip bands; this initiation mechanism is similar to that observed in cast alloy. The second initiation mechanism is related to the grain boundary cracking which takes place predominantly in the fine grained areas.

  10. Warm Deep Drawing Of Rectangular Cups With Magnesium Alloy AZ31 Sheets

    SciTech Connect

    Ren, L. M. [Department of Mechanical and Management Engineering (DIMeG), Polytechnic of Bari, 70126 Bari (Italy); Institute of Metal Research, Chinese Academy of Sciences, 110016 Shenyang (China); Palumbo, G.; Tricarico, L. [Department of Mechanical and Management Engineering (DIMeG), Polytechnic of Bari, 70126 Bari (Italy); Zhang, S. H. [Institute of Metal Research, Chinese Academy of Sciences, 110016 Shenyang (China)

    2007-05-17

    Recently, magnesium alloys have been widely applied in automotive and electronic industries as the lightest weight structural and functional materials. Warm forming of magnesium alloys has attracted much attention due to the very poor formability of Mg alloys at room temperature. The formability of magnesium alloy sheet at elevated temperature is significantly affected by the processing parameters. Among them the forming temperature, the punch speed, the geometrical shape of the blank, the blank holder force and the lubrication are probably the most relevant. In this research, the deep drawing of rectangular cups with AZ31 sheets was conducted at elevated temperatures with different process parameters. The finite element analyses were performed to investigate the effects of the process parameters on the formability of rectangular cup drawing and to predict the process defects during the process. The material yield condition was modeled using the isotropic Von Mises criterion. The flow stress data were obtained from tensile tests.

  11. Thermal stability and Bi diffusion in the implanted AZ111 photoresist

    NASA Astrophysics Data System (ADS)

    Guimarães, R. B.; Amaral, L.; Livi, R. P.; De Souza, J. P.; Behar, M.; Zawislak, F. C.

    1988-05-01

    The Rutherford backscattering technique has been used to study the thermal stability modifications induced by the ion implantation process. In agreement with previous results, it is observed that a nonimplanted AZ111 photoresist film starts to decompose at 200 ° C. On the other hand the same film after being shallowly implanted with a low dose of Bi ions remains stable up to 350 ° C. In addition it is observed that Bi diffuses preferentially towards the bulk. At 300°C two different diffusion coefficients are estimated, one for the damaged region Dd = 1.2 × 10 -15cm2/ s, and another for the bulk Db = 1.2 × 10 -14cm/ s. It is suggested that both phenomena, the inhibited diffusion in the implanted region and the elevation in the stabilization temperature of the polymer, should be related to the damage produced by the implantation.

  12. Range measurements and thermal stability study of AZ111 photoresist implanted with Bi ions

    NASA Astrophysics Data System (ADS)

    Guimarães, R. B.; Amaral, L.; Behar, M.; Zawislak, F. C.; Fink, D.

    1988-04-01

    The Rutherford backscattering technique has been used to determine the range parameters of Bi ions implanted into AZ111 photoresist film at energies from 10 to 400 keV. An overall good agreement is found between the experimental results and the theoretical predictions by Biersack, Ziegler, and Littmark. It is also observed that a variation in the implantation dose does not affect the projected range and range straggling results, despite the fact that chemical modification of the implanted polymer layer is detected. In addition, we find that a shallow implantation of the polymer film with Bi ions increases the temperature at which the photoresist starts to decompose. Finally, at 300 °C the implanted Bi atoms diffuse preferentially toward the bulk. For this temperature, two different diffusion coefficients are estimated, one for the damaged region Dd=1.2×10-5 cm2/s and another for the bulk Db=1.2×10-14 cm2/s.

  13. Proximity of H2A.Z containing nucleosome to the transcription start site influences gene expression levels in the mammalian liver and brain

    PubMed Central

    Bargaje, Rhishikesh; Alam, Mohammad Parwez; Patowary, Ashok; Sarkar, Maharnob; Ali, Tamer; Gupta, Shivani; Garg, Manali; Singh, Meghna; Purkanti, Ramya; Scaria, Vinod; Sivasubbu, Sridhar; Brahmachari, Vani; Pillai, Beena

    2012-01-01

    Nucleosome positioning maps of several organisms have shown that Transcription Start Sites (TSSs) are marked by nucleosome depleted regions flanked by strongly positioned nucleosomes. Using genome-wide nucleosome maps and histone variant occupancy in the mouse liver, we show that the majority of genes were associated with a single prominent H2A.Z containing nucleosome in their promoter region. We classified genes into clusters depending on the proximity of H2A.Z to the TSS. The genes with no detectable H2A.Z showed lowest expression level, whereas H2A.Z was positioned closer to the TSS of genes with higher expression levels. We confirmed this relation between the proximity of H2A.Z and expression level in the brain. The proximity of histone variant H2A.Z, but not H3.3 to the TSS, over seven consecutive nucleosomes, was correlated with expression. Further, a nucleosome was positioned over the TSS of silenced genes while it was displaced to expose the TSS in highly expressed genes. Our results suggest that gene expression levels in vivo are determined by accessibility of the TSS and proximity of H2A.Z. PMID:22821566

  14. PRC1 and PRC2 Are Not Required for Targeting of H2A.Z to Developmental Genes in Embryonic Stem Cells

    PubMed Central

    Illingworth, Robert S.; Botting, Catherine H.; Grimes, Graeme R.; Bickmore, Wendy A.; Eskeland, Ragnhild

    2012-01-01

    The essential histone variant H2A.Z localises to both active and silent chromatin sites. In embryonic stem cells (ESCs), H2A.Z is also reported to co-localise with polycomb repressive complex 2 (PRC2) at developmentally silenced genes. The mechanism of H2A.Z targeting is not clear, but a role for the PRC2 component Suz12 has been suggested. Given this association, we wished to determine if polycomb functionally directs H2A.Z incorporation in ESCs. We demonstrate that the PRC1 component Ring1B interacts with multiple complexes in ESCs. Moreover, we show that although the genomic distribution of H2A.Z co-localises with PRC2, Ring1B and with the presence of CpG islands, H2A.Z still blankets polycomb target loci in the absence of Suz12, Eed (PRC2) or Ring1B (PRC1). Therefore we conclude that H2A.Z accumulates at developmentally silenced genes in ESCs in a polycomb independent manner. PMID:22496869

  15. Systematic understanding of corrosion behavior of plasma electrolytic oxidation treated AZ31 magnesium alloy using a mouse model of subcutaneous implant.

    PubMed

    Jang, Yongseok; Tan, Zongqing; Jurey, Chris; Collins, Boyce; Badve, Aditya; Dong, Zhongyun; Park, Chanhee; Kim, Cheol Sang; Sankar, Jagannathan; Yun, Yeoheung

    2014-12-01

    This study was conducted to identify the differences between corrosion rates, corrosion types, and corrosion products in different physiological environments for AZ31 magnesium alloy and plasma electrolytic oxidation (PEO) treated AZ31 magnesium alloy. In vitro and in vivo tests were performed in Hank's Balanced Salt Solution (HBSS) and mice for 12 weeks, respectively. The corrosion rates of both AZ31 magnesium alloy and PEO treated AZ31 magnesium alloy were calculated based on DC polarization curves, volume of hydrogen evolution, and the thickness of corrosion products formed on the surface. Micro X-ray computed tomography (Micro-CT), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) were used to analyze morphological and chemical characterizations of corrosion products. The results show that there is more severe localized corrosion after in vitro test in HBSS; however, the thicknesses of corrosion products formed on the surface for AZ31 magnesium alloy and PEO treated AZ31 magnesium alloy in vivo were about 40% thicker than the thickness of corrosion products generated in vitro. The ratio of Ca and P (Ca/P) in the corrosion products also differed. The Ca deficient region and higher content of Al in corrosion product than AZ31 magnesium alloy were identified after in vivo test in contrast with the result of in vitro test. PMID:25491800

  16. Effect of Stress Triaxiality on the Flow and Fracture of Mg Alloy AZ31

    NASA Astrophysics Data System (ADS)

    Kondori, Babak; Benzerga, A. Amine

    2014-07-01

    The microscopic damage mechanisms operating in a hot-rolled magnesium alloy AZ31B are investigated under both uniaxial and controlled triaxial loadings. Their connection to macroscopic fracture strains and fracture mode (normal vs shear) is elucidated using postmortem fractography, interrupted tests, and microscopic analysis. The fracture locus (strain-to-failure vs stress triaxiality) exhibits a maximum at moderate triaxiality, and the strain-to-failure is found to be greater in notched specimens than in initially smooth ones. A transition from twinning-induced fracture under uniaxial loading to microvoid coalescence fracture under triaxial loading is evidenced. It is argued that this transition accounts in part for the observed greater ductility in notched bars. The evolution of plastic anisotropy with stress triaxiality is also investigated. It is inferred that anisotropic plasticity at a macroscopic scale suffices to account for the observed transition in the fracture mode from flat (triaxial loading) to shear-like (uniaxial loading). Damage is found to initiate at second-phase particles and deformation twins. Fracture surfaces of broken specimens exhibit granular morphology, coarse splits, twin-sized crack traces, as well as shallow and deep dimples, in proportions that depend on the overall stress triaxiality and fracture mode. An important finding is that AZ31B has a greater tolerance to ductile damage accumulation than has been believed thus far, based on the fracture behavior in uniaxial specimens. Another finding, common to both tension and compression, is the increase in volumetric strain, the microscopic origins of which remain to be elucidated.

  17. Archaeological studies at Drill Hole U20az Pahute Mesa, Nye county, Nevada. [Contains bibliography

    SciTech Connect

    Simmons, A.H.; Hemphill, M.L.; Henton, G.H.; Lockett, C.L.; Nials, F.L.; Pippin, L.C.; Walsh, L.

    1991-07-01

    During the summer of 1987, the Quaternary Sciences Center (formerly Social Science Center) of the Desert Research Institute (DRI), University of Nevada System, conducted data recovery investigations at five archaeological sites located near Drill Hole U20az on the Nevada Test Site in southern Nevada. These sites were among 12 recorded earlier during an archaeological survey of the drill hole conducted as part of the environmental compliance activities of the Department of Energy (DOE). The five sites discussed in this report were considered eligible for the National Register of Historic Places and were in danger of being adversely impacted by construction activities or by effects of the proposed underground nuclear test. Avoidance of these sites was not a feasible alternative; thus DRI undertook a data recovery program to mitigate expected adverse impacts. DRI's research plan included controlled surface collections and excavation of the five sites in question, and had the concurrence of the Nevada Division of Historic Preservation and Archaeology and the Advisory Council of Historic Preservation. Of the five sites investigated, the largest and most complex, 26Ny5207, consists of at least three discrete artifact concentrations. Sites 26Ny5211 and 26Ny5215, both yielded considerable assemblages. Site 26Ny5206 is very small and probably is linked to 26Ny5207. Site 26Ny5205 contained a limited artifact assemblage. All of the sites were open-air occurrences, and, with one exception contained no or limited subsurface cultural deposits. Only two radiocarbon dates were obtained, both from 26Ny5207 and both relatively recent. While the investigations reported in the volume mitigate most of the adverse impacts from DOE activities at Drill Hole U20az, significant archaeological sites may still exist in the general vicinity. Should the DOE conduct further activities in the region, additional cultural resource investigations may be required. 132 refs., 71 figs., 44 tabs.

  18. Friction Stir Welded AZ31 Magnesium Alloy: Microstructure, Texture, and Tensile Properties

    NASA Astrophysics Data System (ADS)

    Chowdhury, S. H.; Chen, D. L.; Bhole, S. D.; Cao, X.; Wanjara, P.

    2013-01-01

    This study was aimed at characterizing the microstructure, texture and tensile properties of a friction stir welded AZ31B-H24 Mg alloy with varying tool rotational rates and welding speeds. Friction stir welding (FSW) resulted in the presence of recrystallized grains and the relevant drop in hardness in the stir zone (SZ). The base alloy contained a strong crystallographic texture with basal planes (0002) largely parallel to the rolling sheet surface and < {11bar{2}0} rangle directions aligned in the rolling direction (RD). After FSW the basal planes in the SZ were slightly tilted toward the TD determined from the sheet normal direction (or top surface) and also slightly inclined toward the RD determined from the transverse direction (or cross section) due to the intense shear plastic flow near the pin surface. The prismatic planes (10bar{1}0) and pyramidal planes (10bar{1}1) formed fiber textures. After FSW both the strength and ductility of the AZ31B-H24 Mg alloy decreased with a joint efficiency in-between about 75 and 82 pct due to the changes in both grain structure and texture, which also weakened the strain rate dependence of tensile properties. The welding speed and rotational rate exhibited a stronger effect on the YS than the UTS. Despite the lower ductility, strain-hardening exponent and hardening capacity, a higher YS was obtained at a higher welding speed and lower rotational rate mainly due to the smaller recrystallized grains in the SZ arising from the lower heat input.

  19. 26. 'CITY HOSPITAL, BLACKWELL'S ISLAND.' (Source: New York City Department ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    26. 'CITY HOSPITAL, BLACKWELL'S ISLAND.' (Source: New York City Department of Public Finance, Real Estate Owned by the City of New York under Jurisdiction of the Department of Public Charities, 1909.) - Island Hospital, Roosevelt Island, New York, New York County, NY

  20. Most Frequently Traveled Cities and States City/State Miles

    E-print Network

    Hardy, Christopher R.

    Lake City, UT 4114 San Antonio, TX 2560 San Diego, CA 5238 San Francisco, CA 4906 Sarasota, FL 2082 Toledo, OH 918 Toronto, Ont. 840 Towson, MD 140 Trenton, NJ 182 University Park, MD 216 UniversityMost Frequently Traveled Cities and States City/State Miles Akron, OH 682 Albany, NY 518 Alexandria

  1. AGU Press Briefing May 29th: Urban Ecology of Phoenix, AZ.

    NSDL National Science Digital Library

    Stuart Snodgrass

    2001-05-22

    Ecologists now accept human beings and our activities as a significant influence on the Earths ecology. ASTER data is being used to better understand urban ecology, in particular how humans build their cities and affect the surrounding environment. Will Stefanov of Arizona State University will present the first set of ASTER images of the urban skeleton of the amount of built structures in 12 cities around the world and discuss the Urban Environmental Monitoring project which will examine 100 urban centers to look for common features (or lack of them) in global city structure and monitor change over time.

  2. Bug City: Beetles [Videotape].

    ERIC Educational Resources Information Center

    1998

    "Bug City" is a video series created to help children learn about insects and other small critters. All aspects of bug life are touched upon including body structure, food, habitat, life cycle, mating habits, camouflage, mutualism (symbiosis), adaptations, social behavior, and more. Each program features dramatic microscopic photography, fun…

  3. Bug City: Ants [Videotape].

    ERIC Educational Resources Information Center

    1998

    "Bug City" is a video series created to help children (grades 1-6) learn about insects and other small critters. All aspects of bug life are touched upon including body structure, food, habitat, life cycle, mating habits, camouflage, mutualism (symbiosis), adaptations, social behavior, and more. Each program features dramatic microscopic…

  4. Bug City: Bees [Videotape].

    ERIC Educational Resources Information Center

    1998

    "Bug City" is a video series created to help children learn about insects and other small critters. All aspects of bug life are touched upon including body structure, food, habitat, life cycle, mating habits, camouflage, mutualism (symbiosis), adaptations, social behavior, and more. Each program features dramatic microscopic photography, fun…

  5. City model enrichment

    NASA Astrophysics Data System (ADS)

    Smart, Philip D.; Quinn, Jonathan A.; Jones, Christopher B.

    The combination of mobile communication technology with location and orientation aware digital cameras has introduced increasing interest in the exploitation of 3D city models for applications such as augmented reality and automated image captioning. The effectiveness of such applications is, at present, severely limited by the often poor quality of semantic annotation of the 3D models. In this paper, we show how freely available sources of georeferenced Web 2.0 information can be used for automated enrichment of 3D city models. Point referenced names of prominent buildings and landmarks mined from Wikipedia articles and from the OpenStreetMaps digital map and Geonames gazetteer have been matched to the 2D ground plan geometry of a 3D city model. In order to address the ambiguities that arise in the associations between these sources and the city model, we present procedures to merge potentially related buildings and implement fuzzy matching between reference points and building polygons. An experimental evaluation demonstrates the effectiveness of the presented methods.

  6. Vilnius City Theriofauna

    Microsoft Academic Search

    Kazimieras Baranauskas; Linas Bal?iauskas; Reda Mažeikyt?

    2005-01-01

    Mammal diversity investigations in Vilnius were carried out in 1992, 1998–2004. The following 51 mammal species were registered in the city: five species of insectivores (Insectivora), 11 of bats (Chiroptera), 18 of rodents (Rodentia), two of hares (Lagomorpha), 11 of carnivores (Carnivora) and four of ungulates (Artiodactyla). Fourteen mammal species are included into the Red Data Book of Lithuania, namely

  7. Visit Cell City

    NSDL National Science Digital Library

    Sue Glass

    2007-12-12

    In this online activity, students search the Web in order to learn about human body cells. After collecting their research, they make an analogy between the structure of a human liver cell and a real city. Included are activity pages, team pages, teacher pages, and a list of electronic resources that students will need to complete the activity.

  8. American City Business Journals

    E-print Network

    American City Business Journals electronic editions Now available to all George Mason University of all the weekly business journals around the country. Read them online, or print/download selected pages to read on the go. Features include: In-depth local business news coverage, Interviews with Top

  9. Hazards in the City

    NSDL National Science Digital Library

    2010-10-04

    In this interactive activity adapted from the National Library of Medicine, explore the environmental hazards that might be found at various locations within cities and towns, including construction sites, factories, homes, hospitals, offices and stores, parks, restaurants, rivers and lakes, schools, and vehicles. A background essay, discussion questions, and standards correlations are also provided.

  10. Clean Cities Natural Gas

    E-print Network

    2014 Vehicle Buyer's Guide Clean Cities Natural Gas Propane Biodiesel Electric Hybrid Ethanol Flex . . . . . . . . . . . . . . . . . . . . . 15 Plug-In Hybrid Electric . . . . . . . . . . 18 Hybrid Electric vehicles, and hybrid luxury cars are now in the marketplace. Early in the 2013 calendar year the number

  11. New City, New Challenges

    ERIC Educational Resources Information Center

    Matthews, Frank

    2010-01-01

    After eight years at the helm of the City College of New York, where Dr. Gregory Williams grew enrollment at the minority-serving institution by 60 percent, instituted more rigorous admissions standards and launched the college's first capital campaign that raised more than $300 million, last fall he became the 27th president of the University of…

  12. Governor of (City), (State)

    E-print Network

    Honorable Governor of (City), (State) Dear Governor : Section 112(l) of the Clean Air Act Amendments of 1990, P.L. 101-549 (November 15, 1990) provides for delegation of authority to a State) if such State submits an adequate procedure for doing so. We are hereby transmitting a statement

  13. Cities and Sustainable Development

    E-print Network

    water and sanitation, combat human-induced climate change, and protect biodiversity. Achieving, Beijing, Rio de Janeiro, and Port-au-Prince, to name just a few ­ pummeled in recent years by climate, helping to slash extreme poverty. Cities are also the innovation hubs for public policy. Every day, #12

  14. City Night Lights Poster

    NSDL National Science Digital Library

    2002-01-01

    This poster shows a global view of Earth at night, compiled from over 400 satellite images collected during the nighttime phase of the orbit. Much of Earth is illuminated at night by city lights. The poster includes elementary-secondary activities on the backside from Mission Geography (http://missiongeography.org/).

  15. TELECOM-CITIES

    NSDL National Science Digital Library

    TELECOM-CITIES, a discussion list sponsored by the Taub Urban Research Center at New York University, focuses on practical and theoretical aspects of the impacts of advanced telecommunications and telematics on urban centers. A web-based subscription form is available.

  16. Big-City Rules

    ERIC Educational Resources Information Center

    Gordon, Dan

    2011-01-01

    When it comes to implementing innovative classroom technology programs, urban school districts face significant challenges stemming from their big-city status. These range from large bureaucracies, to scalability, to how to meet the needs of a more diverse group of students. Because of their size, urban districts tend to have greater distance…

  17. WHO Healthy Cities Programme.

    PubMed

    Goldstein, G; Kickbusch, I

    1996-03-01

    This article identifies some urban health challenges and discusses World Health Organization (WHO) concepts of public health, a Municipal Health Plan, and the WHO Healthy Cities Program (HCP). A healthy city is defined as one that continually creates and improves the physical and social environment and expands community resources for enabling the mutual support among population groups for living. Urbanization is advancing rapidly, but government resources are not keeping pace with people's needs. By 1990, at least 600 million urban people in developing countries faced life and health threats. There is poverty, inadequate food and shelter, insecure tenure, physical crowding, poor waste disposal, unsafe working conditions, inadequate local government services, overuse of harmful substances, and environmental pollution. Poor people in cities frequently must satisfy all their basic needs in health, welfare, and employment. There is exposure to early sexual activity of adolescents, transient relationships, high levels of prostitution, and limited birth control. Unsustainable use of natural resources and environmental destruction pose threats to urban productivity and restrict future development options. The WHO launched a "Health for All" campaign in 1978, based on 4 basic principles. The HCP, which is based on these principles, has expanded to many cities. It measures the health burden and makes health issues relevant and understandable to local agencies through analysis and policy advocacy. The Municipal Health Plan facilitates awareness of environmental and health problems in schools, work and marketplaces, health services, and among other organizations. PMID:12178494

  18. Sinking coastal cities

    NASA Astrophysics Data System (ADS)

    Erkens, Gilles; Bucx, Tom; Dam, Rien; De Lange, Ger; Lambert, John

    2014-05-01

    In many coastal and delta cities land subsidence now exceeds absolute sea level rise up to a factor of ten. Without action, parts of Jakarta, Ho Chi Minh City, Bangkok and numerous other coastal cities will sink below sea level. Land subsidence increases flood vulnerability (frequency, inundation depth and duration of floods), with floods causing major economic damage and loss of lives. In addition, differential land movement causes significant economic losses in the form of structural damage and high maintenance costs. This effects roads and transportation networks, hydraulic infrastructure - such as river embankments, sluice gates, flood barriers and pumping stations -, sewage systems, buildings and foundations. The total damage worldwide is estimated at billions of dollars annually. Excessive groundwater extraction after rapid urbanization and population growth is the main cause of severe land subsidence. In addition, coastal cities are often faced with larger natural subsidence, as they are built on thick sequences of soft soil. Because of ongoing urbanization and population growth in delta areas, in particular in coastal megacities, there is, and will be, more economic development in subsidence-prone areas. The impacts of subsidence are further exacerbated by extreme weather events (short term) and rising sea levels (long term).Consequently, detrimental impacts will increase in the near future, making it necessary to address subsidence related problems now. Subsidence is an issue that involves many policy fields, complex technical aspects and governance embedment. There is a need for an integrated approach in order to manage subsidence and to develop appropriate strategies and measures that are effective and efficient on both the short and long term. Urban (ground)water management, adaptive flood risk management and related spatial planning strategies are just examples of the options available. A major rethink is needed to deal with the 'hidden' but urgent threat of subsidence. As subsidence is spatially different and can be caused by multi processes, an assessment of subsidence in delta cities needs to answer questions such as: what are the main causes, how much is the current subsidence rate and what are future scenarios (and interaction with other major environmental issues), where are the vulnerable areas, what are the impacts and risks, how can adverse impacts can be mitigated or compensated for, and who is involved and responsible to act? In this study a quick-assessment of subsidence is performed on the following mega-cities: Jakarta, Ho Chi Minh City, Dhaka, New Orleans and Bangkok. Results of these case studies will be presented and compared, and a (generic) approach how to deal with subsidence in current and future subsidence-prone areas is provided.

  19. 75 FR 20920 - Safety Zone; Lake Havasu Grand Prix, Lake Havasu, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-22

    ...waters of Lake Havasu on the Colorado River in Lake Havasu City, Arizona...would either preempt State law or impose a substantial...inconsistent with applicable law or otherwise impractical...local, State, and Federal law enforcement vessels...

  20. 75 FR 10552 - Noise Exposure Map Notice for Chandler Municipal Airport, Chandler, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-08

    ...Aviation Administration Noise Exposure Map Notice for Chandler Municipal Airport...its determination that the noise exposure maps submitted by City of Chandler, for Chandler...FAA's determination on the noise exposure maps is February 19, 2010. FOR FURTHER...

  1. 76 FR 30907 - Proposed Foreign-Trade Zone-Eloy, AZ; Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-27

    ...opposite Sasco Road, Red Rock. The sites are owned by the City of Eloy (Site 1), Walton International Group (USA), Inc. and Walton Arizona, LLC (Site 2), Walton International Group (USA), Inc. (Site 3) and Walton International...

  2. City of Toronto 2001TRAFFICZONES

    E-print Network

    Toronto, University of

    ! City of Toronto 2001TRAFFICZONES CITYOFTORONTO B.1 B.9 B.10 B.11 B.12 B.13 #12;! Durham Region. ! VICTORIAPARKAVE. 2001 TRAFFIC ZONES CITY OF TORONTO B.12B.22 B.9 B.13B.11 6 43 5 #12;449 462 463 459 448 461 445. MARKHAMRD. SCARBOROUGH-PICKERINGTOWNLINE MORNINGSIDEAVE. FINCH AVE. ! 2001 TRAFFIC ZONES CITY OF TORONTO B

  3. New York City's Education Battles

    ERIC Educational Resources Information Center

    Meyer, Peter

    2008-01-01

    When Bloomberg gave his first State of the City address, in January, 2002, he announced his intention to seek mayoral control of the schools and abolish the infamous New York City Board of Education, which he called "a rinky-dink candy store." He joined a long list of New York mayors, educators, and business leaders who believed that the city's…

  4. Competitive Cities and Climate Change

    Microsoft Academic Search

    Lamia Kamal-Chaoui; Alexis Robert

    2009-01-01

    Cities are part of the climate change problem, but they are also a key part of the solution. This report offers a comprehensive analysis of how cities and metropolitan regions can change the way we think about responding to climate change. Cities consume the vast majority of global energy and are therefore major contributors of greenhouse gas emissions. At the

  5. NEW YORK CITY NONPROFIT EXECUTIVE

    E-print Network

    Rosen, Jay

    NEW YORK CITY NONPROFIT EXECUTIVE OUTLOOK SURVEY SPONSORED BY THE SCHOOL OF PUBLIC AFFAIRS NONPROFIT GROUP AND SURVEY RESEARCH UNIT SPRING 2006 Better City Outlook, Despite Federal Policies HUMAN CITY NONPROFIT EXECUTIVE OUTLOOK SURVEY SPRINg 2006 BARUCH COLLEgE One Bernard Baruch Way, d ­ 901 ne

  6. Mexico City, Mexico, Commuter Rail

    Microsoft Academic Search

    Beatriz Rutzen; Nathan Hutson; Lisa Loftus-Otway

    2010-01-01

    The Mexico City Metropolitan Area in Mexico has grown beyond the original confines of the Federal District and sprawled into surrounding cities located in Mexico State. This transition from a large but centralized city to a sprawling megalopolis means that the challenge of providing services, including adequate transportation options, to the population is growing exponentially. In response to the growing

  7. Rapid City, SD Showcase Streamgage

    USGS Multimedia Gallery

    A USGS South Dakota Water Science Center streamgage was dedicated by Congressional and city officials on September 3 in Rapid City. This showcase streamgage is located on Rapid Creek at Rapid City in Founders Park and provides visitors with critical information about how streamflow is meas...

  8. The Future of American Cities.

    ERIC Educational Resources Information Center

    Gordon, Dan

    1990-01-01

    Downtown developments have saved some cities from collapse but don't make up for the loss of federal funds, nor do they provide jobs or housing suitable for most inner city residents. Nothing, however, has hurt the inner cities more than drug use. (DM)

  9. University of Minnesota Twin Cities

    E-print Network

    Amin, S. Massoud

    University of Minnesota Twin Cities Emergency Operations Plan © 2011 Regents of the University of Minnesota. All rights reserved. Revision 5.0, September 2011 #12;University of Minnesota - Twin Cities - Twin Cities Emergency Operations Plan Revision 5.0 TABLE OF CONTENTS Basic Plan Introduction Purpose

  10. Smart cities and service integration

    Microsoft Academic Search

    Taewoo Nam; Francisco Armando Aldama; Hafedh Chourabi; Sehl Mellouli; Theresa A. Pardo; J. Ramon Gil-Garcia; Hans Jochen Scholl; Adegboyega Ojo; Elsa Estevez; Lei Zheng

    2011-01-01

    E-government advancements have not fully resolved the challenge of providing citizens with a single entry point for services that involve different government entities. The Smart Cities and Service Integration project (hereafter, SmartCities) aims to establish a framework for smart city service integration that would assist in the management of large scale projects related to the integration of services across governments.

  11. City-City Correlations to Introduce Galaxy-Galaxy Correlations

    NASA Astrophysics Data System (ADS)

    Smith, D. M.

    2014-07-01

    The large-scale structure of the Universe, vividly displayed by the spatial distribution of galaxies, is characterised quanti- tatively by the two-point galaxy-galaxy correlation function. But the meaning of the correlation function is somewhat abstract because it does not have a ready analogy. This work computes the two-dimensional, two-point city-city correlation function for three populous regions of the United States, demonstrating that the city-city correlation function is analogous to the galaxy-galaxy correlation function determined from Sloan Digital Sky Survey data. City radii are analogous to galaxy cluster radii, and city-to-city distances are analogous to distances between galaxy clusters. Part of this work has been adapted for a lab suitable for non-experts.

  12. Inner City Press

    NSDL National Science Digital Library

    Based in the South Bronx, the Inner City Press has been publishing a newspaper focused on low-income neighborhoods nationwide since 1987. A few months ago, the organization went online with a weekly publication featuring original and engaging investigative and analytical pieces from a selection of beats, including the Federal Reserve, Community Reinvestment, Insurance Redlining, Wall Street, Environmental Justice, and Banks, among others. The most recent issue (August 30) includes concise reports on predatory lending, the economic crisis in Ecuador, press leaks and the Federal Reserve, and a round-up of bank news. The site also provides overviews and related resources for Community Reinvestment, the Inner City Public Interest Law Center, Environmental Justice, Insurance Redlining, and related topics.

  13. Vatican City State

    NSDL National Science Digital Library

    On February 11, 1929 the Vatican City State was inaugurated with the signing of the Lateran Accords. With its motto, "A small territory with a great mission", the State is celebrating its 80th anniversary with a number of celebrations this year. This very fine site brings together a veritable cornucopia of information about the Vatican City State, including information about its governance structure, monuments, and philatelic culture. Visitors can start their journey by looking at webcams that provide a top-notch view of St. Peter's Square and the Governorate Palace. Moving on, visitors can also click on the "History" section to learn about the long history of the Vatican, and how the term has been used over the millennia. Visitors can also listen in to Vatican Radio, and check up on official news releases from the Vatican Information Service.

  14. CEOs for Cities

    NSDL National Science Digital Library

    The past few years have seen a growing number of organizations, institutions, and national think tanks express an increasing concern for sustaining the competitive economic advantage of major urban areas. One such group is CEOS for Cities, which is a national bipartisan alliance of mayors, corporate executives, university presidents, and other nonprofit leaders whose primary directive is to advance the economic competitiveness of cities. The group's executive committee includes such powerful leaders as Mayor Richard M. Daley of Chicago and Paul S. Grogan, the CEO of the Boston Foundation. One of the site's best features is the Trends and Data Analysis Reports, coupled with the Best Practice reports. Many of these documents are co-authored with other like-minded institutions, such as the Brookings Institution, and delve into such topics as What the IT Revolution Means for Regional Economic Development and Leveraging Colleges and Universities for Urban Economic Revitalization: An Action Agenda.

  15. URBZ: User Generated Cities

    NSDL National Science Digital Library

    The User Generated Cities organization (URBZ) "facilitates the production and exchange of information, knowledge, ideas and practices towards better cities for all." With offices in Mumbai and Geneva, URBZ deploys a variety of web-based tools "for the production and sharing of information by residents and stakeholders." On their homepage, visitors can read postings from staff members on the construction of multi-story buildings in the developing world and sustainable architecture design charrettes. Moving on, visitors can learn more about URBZ by clicking on the "Workshops" section. Here they will find diagrams and explanations of URBZ's design philosophy and their work with local communities. Interested parties can also sign up here to receive email updates and to learn more about their upcoming events.

  16. Lost City Expedition

    NSDL National Science Digital Library

    University of Washington

    This website provides an account of a research cruise to the Lost City Hydrothermal Field at the summit of the Atlantis Massif. During this 32-day expedition, scientists onboard the research vessel Atlantis explored active limestone chimneys that rise 200 feet above the seafloor. This site features information about the biology, chemistry and geology of the Lost City area, as well as explanations of the instruments used to sample and analyze these parameters. It also describes how researchers used the robotic Autonomous Benthic Vehicle and three-person submarine Alvin to explore, map and sample the sea floor. The site also includes a daily shipboard journal, a glossary, and an ask-a-scientist online form. This extensive site provides in-depth, broadly accessible information about the science, mapping and operations of this expedition and hydrothermal systems in general.

  17. Pittsburgh City Photographer

    NSDL National Science Digital Library

    The Archives Service Center and the Digital Research Library at the University of Pittsburgh have made over 1,200 pictures of Pittsburgh taken by the Pittsburgh City Photographer between 1901 and 1969 available online. Included are views of Pittsburgh parks and recreation facilities, athletic and mayoral events, general street scenes and traffic, as well as interior and exterior shots of familiar Pittsburgh buildings, including some that have been demolished. There are also interesting depictions of home life, and the famous and not so famous people of Pittsburgh. For example, a search on Highland Park retrieves 20 images dating from 1901 - 1968, and includes families at the Childrens' Zoo in the 1960s; various views of the entrance to Highland Park; an early image of the Highland Park Reservoir (1907); and DeLucca's market on Bryant St. It is also possible to search the Pittsburgh City Photographer's Collection along with 26 other image collections at the Historic Pittsburgh Image Collections.

  18. City of Chicago Landmarks

    NSDL National Science Digital Library

    The city of Chicago has many hundreds of wonderful architectural landmarks and this helpful website is a great resource for anyone with an interest in such matters. On the site, visitors can start by checking out the Landmarks Tours to get started. There over a dozen tours here, including Mansions Tour, Art Deco Tour, and Pre-Fire Chicago Tour. Moving on, visitors may also wish to look over the Architects area. Here they will encounter some of the usual suspects (Frank Lloyd Wright, Louis Sullivan, etc.) and learn about some lesser-known architects, such as Solon S. Beman and William W. Boyington, who designed the wonderful entrance to Rosehill Cemetery. The Style Guide offers a great primer for those who'd like to know more about two dozen architectural styles, including Craftsman, International, and Tudor Revival. Finally, the site also includes a Listings area, complete with information about all of the buildings on the city's official landmarks list.

  19. City 2.0

    NSDL National Science Digital Library

    2012-01-01

    TED's City 2.0 is "a gathering place for urban citizens to share innovations and inspire actions." The focus of this rather wonderful series of events was to work on envisioning the cities of the future. Visitors to the site will find archived videos from the devoted day of urban inspiration in 2012 and 2013 and they can click through the Videos area to get started. There are over two dozen talks here, including The Art of Data, Globalizing Home and Emerging from the Ecotone. Moving on to the People section, visitors can look over the stories shared from around the globe via the clickable map of the world. Visitors with a specific interest in a certain type of urban success story might want to use the Themes area to look over talks on art, housing, public space, or other matters.

  20. Asthma in inner cities.

    PubMed Central

    LeNoir, M. A.

    1999-01-01

    While the management of asthma has improved over the past two decades, the incidence of asthma in the inner city has not. The inner city, comprising a disproportionate number of people who live close to or below the poverty line, shows increased rates of morbidity and mortality from asthma. African Americans and Hispanic Americans are two to six times more likely to die from asthma than their white counterparts. When federally funded programs have targeted reducing morbidity and mortality in children from these populations, they have succeeded, but in a national study only 18 states had initiatives targeting asthma in low-income populations. This is tantamount to a public health crisis. Patients are not always properly diagnosed and are often without a regular source of health care, and symptoms are seen only in an acute context. Living conditions for the inner-city child have significant allergen triggers associated with house dust, cockroaches, cigarette smoke, chemical pollutants, and particulate matter. Viral infections, such as those caused by respiratory syncytial virus, are worse in crowded living conditions. The desirability of an increased public awareness of the seriousness of the disease and the need for chronic health care are issues that should be raised, through culturally relevant public means and in the knowledge that visual information is most effective. Physicians must understand the proper use of rescue and controller drugs, and asthma education must expand beyond doctors and nurses in their offices. The National Medical Association is committed to doing this aggressively, and community organizations, alliances, and coalitions must also aggressively follow. Public agencies must be lobbied to set high standards for proper asthma care and resources. With organizations acting in concert, the mortality and morbidity from asthma can be substantially prevented in the inner city. PMID:12653387

  1. The Inner City 100 (2001)

    NSDL National Science Digital Library

    New from Inc.com and the Initiative for a Competitive Inner City, the Inner City 100 highlights 100 of the fastest growing urban businesses in the US. According to Michael Porter, Harvard Business School professor and founder of the Initiative for a Competitive Inner City, "When we started this, I thought we could reverse a lot of bad policies and bad perceptions that have prevented the inner cities from having a place in the economy. I never dreamed the inner city would become a window onto the future of the economy." Along with the listings, this site contains several articles on a variety of related topics including a story on Ahead Headgear, a hat embroiderer in New Bedford, MA rated number one in the Inner City 100; the Inner City 100 Almanac for information about the businesses that made the survey; as well as an article on comeback markets.

  2. Volunteer Application Please return application to: Kellee Hanson | Gould-Simpson 935A | 1040 E. 4th Street | Tucson, AZ 85721-0091 | Fax: (520) 626-1352

    E-print Network

    Holliday, Vance T.

    Volunteer Application Please return application to: Kellee Hanson | Gould-Simpson 935A | 1040 E. 4 application to: Kellee Hanson | Gould-Simpson 935A | 1040 E. 4th Street | Tucson, AZ 85721-0091 | Fax: (520

  3. Raleigh: A Capital City

    NSDL National Science Digital Library

    The story of the United States is told in many different ways, and the National Park Service's National Register of Historic Places offers a number of compelling online tours that allow visitors entry into many of the historic sites scattered around the country. This very nice online tour focuses on Raleigh, N.C., and was commissioned in partnership with the City of Raleigh and a number of related units of government. The tour presented on this site highlights 48 historic places, and includes the city's Victorian neighborhoods and some of the more quotidian commercial buildings around the area. Visitors can navigate these sites through a series of interactive maps, or by a comprehensive list that provides information about the historical significance of each structure or feature of the built environment. The site also contains a number of thematic essays that deal with different stages of the city's development, such as suburbanization. The site is rounded out by a selection of additional links to other online resources on Raleigh history and tourism, along with a select bibliography of relevant works.

  4. H2A.Z depletion impairs proliferation and viability but not DNA double-strand breaks repair in human immortalized and tumoral cell lines

    PubMed Central

    Taty-Taty, Gemael-Cedrick; Courilleau, Celine; Quaranta, Muriel; Carayon, Alexandre; Chailleux, Catherine; Aymard, François; Trouche, Didier; Canitrot, Yvan

    2014-01-01

    In mammalian cells, DNA double-strand breaks (DSB) can be repaired by 2 main pathways, homologous recombination (HR) and non-homologous end joining (NHEJ). To give access to DNA damage to the repair machinery the chromatin structure needs to be relaxed, and chromatin modifications play major roles in the control of these processes. Among the chromatin modifications, changes in nucleosome composition can influence DNA damage response as observed with the H2A.Z histone variant in yeast. In mammals, p400, an ATPase of the SWI/SNF family able to incorporate H2A.Z in chromatin, was found to be important for histone ubiquitination and BRCA1 recruitment around DSB or for HR in cooperation with Rad51. Recent data with 293T cells showed that mammalian H2A.Z is recruited to DSBs and is important to control DNA resection, therefore participating both in HR and NHEJ. Here we show that depletion of H2A.Z in the osteosarcoma U2OS cell line and in immortalized human fibroblasts does not change parameters of DNA DSB repair while affecting clonogenic ability and cell cycle distribution. In addition, no recruitment of H2A.Z around DSB can be detected in U2OS cells either after local laser irradiation or by chromatin immunoprecipitation. These data suggest that the role of H2A.Z in DSB repair is not ubiquitous in mammals. In addition, given that important cellular parameters, such as cell viability and cell cycle distribution, are more sensitive to H2A.Z depletion than DNA repair, our results underline the difficulty to investigate the role of versatile factors such as H2A.Z. PMID:24240188

  5. In vitro and in vivo metabolism of 14C-AZ11, a novel inhibitor of bacterial DNA gyrase/type II topoisomerase.

    PubMed

    Guo, Jian; Joubran, Camil; Luzietti, Ricardo A; Zhou, Fei; Basarab, Gregory S; Vishwanathan, Karthick

    2015-02-01

    1.?(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((S)-4-methyl-2-oxooxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1'H-spiro [isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5'-pyrimidine]-2',4',6'(3'H)-trione (AZ11) is a novel mode-of-inhibition bacterial topoisomerase inhibitor that entered preclinical development for the treatment of Gram-positive bacteria infection. 2.?The in vitro biotransformation studies of AZ11 using mouse, rat, dog and human hepatocytes showed low-intrinsic clearance in all species attributed to microsomal metabolism. 3.?After a single intravenous administration of [14C]AZ11 in bile duct cannulated rats, the mean percentage of dose recovered in rat urine, bile and feces was approximately 18, 36 and 42%, respectively. Unchanged AZ11 recovered in rat urine and bile was less than 9% of the dose, indicating that AZ11 underwent extensive metabolism in rats. 4.?The most abundant in vivo metabolite detected in urine and bile was M1 formed via ring opening on the piperidine and morpholine rings accounting for 20% of the administered dose. The major fecal metabolite was M5, which accounted for approximately 32% of administered dose. M5 was not formed when AZ11 incubated with rat intestinal microsomes and cytosol but was formed when incubated with fresh rat feces, suggesting that unchanged AZ11 was directly excreted into gut lumen where M5 formed as an intestinal microflora-mediated product. This process could have significant impact on bioavailability or exposure of AZ11 in rat. PMID:25142218

  6. PHYSICAL CHARACTERIZATION OF VITREOUS STATE LABORATORY AY102/C106 AND AZ102 HIGH LEVEL WASTE MELTER FEED SIMULANTS (U)

    SciTech Connect

    Hansen, E

    2005-03-31

    The objective of this task is to characterize and report specified physical properties and pH of simulant high level waste (HLW) melter feeds (MF) processed through the scaled melters at Vitreous State Laboratories (VSL). The HLW MF simulants characterized are VSL AZ102 straight hydroxide melter feed, VSL AZ102 straight hydroxide rheology adjusted melter feed, VSL AY102/C106 straight hydroxide melter feed, VSL AY102/C106 straight hydroxide rheology adjusted melter feed, and Savannah River National Laboratory (SRNL) AY102/C106 precipitated hydroxide processed sludge blended with glass former chemicals at VSL to make melter feed. The physical properties and pH were characterized using the methods stated in the Waste Treatment Plant (WTP) characterization procedure (Ref. 7).

  7. A Crystalline Plasticity Finite Element Method for Simulation of the Plastic Deformation of AZ31 Magnesium Alloys

    SciTech Connect

    Li Dayong; Peng Yinghong [School of Mechanical and Power Engineering, Shanghai Jiaotong University, 800 Dongchuan Road, Shanghai (China); State Key Laboratory of Mechanical System and Vibration, Shanghai Jiaotong University, 800 Dongchuan Road, Shanghai (China); Zhang Shaorui; Tang Weiqin; Huang Shiyao [School of Mechanical and Power Engineering, Shanghai Jiaotong University, 800 Dongchuan Road, Shanghai (China)

    2010-06-15

    In this paper, a constitutive framework based on a crystalline plasticity model is employed to simulate the plastic deformation of AZ31 magnesium alloy, which posses the hexagonal close packed (HCP) crystal structure. Dislocation slip and mechanical twinning are taken into account in the model. The successive integration method is used to determine the active slip systems, and the contribution of twinning to the grain reorientation is treated by the PTR method. The FE model is introduced into ABAQUS/Explicit through a user material subroutine (VUMAT). Three deformation processes of AZ31 magnesium alloy, including tension, compression and a stamping process, are simulated with the present method. The simulation results are compared with experiment and those presented in the literature.

  8. Tensile properties of AZ11A-0 magnesium-alloy sheet under rapid-heating and constant temperature

    NASA Technical Reports Server (NTRS)

    Kurg, Ivo M

    1956-01-01

    Specimens of AZ31A-0 magnesium alloy sheet were heated to rupture at nominal rates of 0.2 F to 100 F per second under constant tensile load conditions. The data are presented and compared with the results of conventional tensile stress-strain tests at elevated temperatures after 1.2-hour exposure. A temperature-rate parameter was used to construct master curves from which stresses and temperatures for yield and rupture can be predicted under rapid-heating conditions. A comparison of the elevated-temperature tensile properties of AZ31A-0 and HK31XA-H24 magnesium-alloy sheet under both constant-temperature and rapid-heating conditions is included.

  9. Modeling of high temperature rheological behavior of AZ61 Mg-alloy using inverse method and ANN

    Microsoft Academic Search

    M. Talebi Anaraki; M. Sanjari; A. Akbarzadeh

    2008-01-01

    Inverse method and artificial neural network were employed in modeling the rheological behavior of the AZ61 Mg alloy. The hot deformation behavior of these alloys was investigated by compression tests in the temperature range 250–350°C and strain rate range 0.0005–0.1s?1. Investigation of stress–strain curves and microstructure of the compression specimen illustrate occurrence of dynamic recrystallization. To determining parameters of two

  10. Electrochemical response of ZrO 2-incorporated oxide layer on AZ91 Mg alloy processed by plasma electrolytic oxidation

    Microsoft Academic Search

    Kang Min Lee; Ki Ryong Shin; Seung Namgung; Bongyoung Yoo; Dong Hyuk Shin

    2011-01-01

    ZrO2 nanoparticles well dispersed in an electrolyte were effectively incorporated in an oxidized surface passivation layer on AZ91 Mg alloy by a plasma electrolytic oxidation (PEO) process. The electrophoretic reaction and mechanical mixing in molten magnesium oxide were the main factors leading to incorporation of ZrO2 nanoparticles in the magnesium oxide layer. Incorporated ZrO2 nanoparticles were mainly located in pores

  11. Iron Phosphate Glass for Vitrifying Hanford AZ102 LAW in Joule Heated and Cold Crucible Induction Melters

    SciTech Connect

    Day, Delbert E.; Brow, R. K.; Ray, C. S.; Kim, Cheol-Woon; Reis, Signo T.; Vienna, John D.; Peeler, David K.; Johnson, Fabienne; Hansen, E. K.; Sevigny, Gary J.; Soelberg, Nicolas R.; Pegg, Ian L.; Gan, Hao

    2012-01-05

    An iron phosphate composition for vitrifying a high sulfate (~17 wt%) and high alkali (~80 wt%) low activity Hanford waste, known as AZ102 LAW, has been developed for processing in a Joule Heated Melter (JHM) or a Cold Crucible Induction Melter (CCIM). This composition produced a glass waste form, designated as MS26AZ102F-2, with a waste loading of 26 wt% of the AZ102 which corresponded to a total alkali and sulfate (SO3) content of 21 and 4.2 wt%, respectively. A slurry (7M Na) of MS26AZ102F-2 simulant was melted continuously at temperatures between 1030 and 1090°C for 10 days in a small JHM at PNNL and for 7 days in a CCIM at INL. The as-cast glasses produced in both melters and in trial laboratory experiments along with their CCC-treated counterparts met the DOE LAW requirements for the Product Consistency Test (PCT) and the Vapor Hydration Test (VHT). These glass waste forms retained up to 77 % of the SO3 (3.3 wt%), 100% of the Cesium, and 33 to 44% of the rhenium, surrogate for Tc-99, all of which either exceeded or were comparable to the retention limit for these species in borosilicate glass nuclear waste form. Analyses of commercial K-3 refractory lining and the Inconel 693 metal electrodes used in JHM indicated only minimum corrosion of these components by the iron phosphate glass. This is the first time that an iron phosphate composition (slurry feed) was melted continuously in the JHM and CCIM, thereby, demonstrating that iron phosphate glasses can be used as alternative hosts for vitrifying nuclear waste.

  12. 9.28 Bedrock Rivers KX Whipple and RA DiBiase, Arizona State University, Tempe, AZ, USA

    E-print Network

    Crosby, Benjamin T.

    9.28 Bedrock Rivers KX Whipple and RA DiBiase, Arizona State University, Tempe, AZ, USA BT Crosby 550 9.28.1.1 Definition and Occurrence 551 9.28.1.2 Importance of Bedrock Rivers 551 9.28.1.3 Relation of Flow Hydraulics 552 9.28.2.2 Controls on the Width of Bedrock Rivers 553 9.28.3 Erosion Processes

  13. COUNTRY INSTITUTION DATE WEB ADDRESS AZERBAIJAN Azerbaijan Medical University 15.03.2011 http://amu.edu.az/

    E-print Network

    Guidoni, Leonardo

    ://www.aztu.edu.az/azp/ IRAN Institute of Higher Education of Alaodoleh Semnani 03.10.2011 www.asihe.ac.ir/en IRAN University://www.shirazu.ac.ir/farsi/farsiindex.html IRAN Shirz University of Medical Sciences 02.04.2007 http://www.sums.ac.ir IRAN Higher Education (PALESTINIAN TERRITORIES) An-Najah National University 21.03.2006 http://www.najah.edu PALESTINE (PALESTINIAN

  14. In vitro degradation, hemolysis, and cytocompatibility of PEO/PLLA composite coating on biodegradable AZ31 alloy.

    PubMed

    Wei, Zhongling; Tian, Peng; Liu, Xuanyong; Zhou, Bangxin

    2015-02-01

    Magnesium and its alloys have large potential as degradable and absorbable biomaterials because of their mechanical properties and biocompatibility. However, their corrosion resistance is usually inadequate especially in physiological environment, which limits their broad applications in biomedical areas. In this work, plasma electrolytic oxidized/poly(l-lactide) (PEO/PLLA) composite coating was successfully fabricated on biodegradable AZ31 alloy by combing PEO process and sealing with PLLA. The microstructure, elemental composition, and phase composition of the PEO/PLLA composite coating were investigated. The in vitro degradation of the PEO/PLLA composite coating in simulated body fluid (SBF) was also systematically evaluated. The results revealed that the PEO/PLLA composite coating improved the corrosion resistance of AZ31 alloy significantly. The corrosion potential shifted from -1.663V to more positive position -1.317 V and the corrosion current density was reduced with six-order of magnitude. The Mg(2+) ions, hydrogen release, and pH value change of solution caused by degradation were all decreased significantly. Moreover, the PEO process played a critical role in sustaining the integrity of the implant in long-term service. The result of hemolysis test showed that the PEO/PLLA composite coating vested AZ31 alloy a low hemolysis ratio (0.806?±?0.771)%, which is much lower than the safe value of 5% according to ISO 10993-4. For the cytocompatibility test, compared with bare AZ31 alloy and PEO coating, MC3T3-E1 cells showed much better adhesion and proliferation on the PEO/PLLA composite coating with nearly 4-fold increase of cells after 7-day cultivation, indicating that the PEO/PLLA composite coating has good biocompatibility for biomedical applications. PMID:24889920

  15. Twin-roll strip casting of AZ61 magnesium alloy and improvement of formability by structure-control rolling

    Microsoft Academic Search

    T. Mino; M. Asakawa; D. Lee; T. Fujiwara; K. Matsuzaki; M. Kobayashi

    2006-01-01

    Continuous strip casting and direct rolling method are receiving attention as the integrated producing process to obtain wrought magnesium alloys. In this research, AZ61 strip was cast from molten metal by twin-roll strip caster and rolled by “Structure-Control rolling process”. The effects of casting conditions and rolling parameters on surface aspects and microstructure of the rolled sheet were investigated. The

  16. Assessing the dependence of (51)V A(z) value on the aromatic ring orientation of V(IV)O(2+) pyridine complexes.

    PubMed

    Micera, Giovanni; Pecoraro, Vincent L; Garribba, Eugenio

    2009-07-01

    Characterization of V(IV) biomolecules relies strongly on electron paramagnetic resonance (EPR) spectroscopy, particularly the application of the additivity relationship of A(z) values. It has been shown experimentally that the A(z) values of V(IV)O(2+) imidazole species have a critical angular dependence. Density-functional theory (DFT) calculations elucidate the dependence of (51)V A(z) value on the orientation of the aromatic ring in V(IV)O(2+) pyridine complexes, following closely the functional dependence observed for V(IV)O(2+) imidazole species, [A(z)(pyr) = 42.23 + 1.80 x sin(2theta - 90)], with A(z) measured in 10(4) cm(-1). A DFT re-examination of V(IV)O(2+) imidazole complexes gives an equation very similar [A(z)(imid) = 42.35 + 2.34 x sin(2theta - 90)] to that experimentally found. These results generalize the application of the additivity relationship for V(IV)O(2+) complexes containing aromatic nitrogen ligands such as pyridine or imidazole. The increase of the absolute value of A(z), |A(z)|, when the dihedral angle theta between the V=O and N(pyr)-C or N(imid)-C bonds varies from a parallel to a perpendicular orientation is due to an increase of the d vanadium orbital contribution and to a decrease of the pi aromatic system participation in the singly occupied molecular orbital. PMID:19449891

  17. Large cities are less green

    PubMed Central

    Oliveira, Erneson A.; Andrade, José S.; Makse, Hernán A.

    2014-01-01

    We study how urban quality evolves as a result of carbon dioxide emissions as urban agglomerations grow. We employ a bottom-up approach combining two unprecedented microscopic data on population and carbon dioxide emissions in the continental US. We first aggregate settlements that are close to each other into cities using the City Clustering Algorithm (CCA) defining cities beyond the administrative boundaries. Then, we use data on CO2 emissions at a fine geographic scale to determine the total emissions of each city. We find a superlinear scaling behavior, expressed by a power-law, between CO2 emissions and city population with average allometric exponent ? = 1.46 across all cities in the US. This result suggests that the high productivity of large cities is done at the expense of a proportionally larger amount of emissions compared to small cities. Furthermore, our results are substantially different from those obtained by the standard administrative definition of cities, i.e. Metropolitan Statistical Area (MSA). Specifically, MSAs display isometric scaling emissions and we argue that this discrepancy is due to the overestimation of MSA areas. The results suggest that allometric studies based on administrative boundaries to define cities may suffer from endogeneity bias. PMID:24577263

  18. Influence of shot peening on corrosion properties of biocompatible magnesium alloy AZ31 coated by dicalcium phosphate dihydrate (DCPD).

    PubMed

    Mhaede, Mansour; Pastorek, Filip; Hadzima, Branislav

    2014-06-01

    Magnesium alloys are promising materials for biomedical applications because of many outstanding properties like biodegradation, bioactivity and their specific density and Young's modulus are closer to bone than the commonly used metallic implant materials. Unfortunately their fatigue properties and low corrosion resistance negatively influenced their application possibilities in the field of biomedicine. These problems could be diminished through appropriate surface treatments. This study evaluates the influence of a surface pre-treatment by shot peening and shot peening+coating on the corrosion properties of magnesium alloy AZ31. The dicalcium phosphate dihydrate coating (DCPD) was electrochemically deposited in a solution containing 0.1M Ca(NO3)2, 0.06M NH4H2PO4 and 10mL/L of H2O2. The effect of shot peening on the surface properties of magnesium alloy was evaluated by microhardness and surface roughness measurements. The influence of the shot peening and dicalcium phosphate dihydrate layer on the electrochemical characteristics of AZ31 magnesium alloy was evaluated by potentiodynamic measurements and electrochemical impedance spectroscopy in 0.9% NaCl solution at a temperature of 22±1°C. The obtained results were analyzed by the Tafel-extrapolation method and equivalent circuit method. The results showed that the application of shot peening process followed by DCPD coating improves the properties of the AZ31 surface from corrosion and mechanical point of view. PMID:24863232

  19. Deposition of histone H2A.Z by the SWR-C remodeling enzyme prevents genome instability.

    PubMed

    Van, Christopher; Williams, Jessica S; Kunkel, Thomas A; Peterson, Craig L

    2015-01-01

    The yeast SWR-C chromatin remodeling enzyme catalyzes chromatin incorporation of the histone variant H2A.Z which plays roles in transcription, DNA repair, and chromosome segregation. Dynamic incorporation of H2A.Z by SWR-C also enhances the ability of exonuclease I (Exo1) to process DNA ends during repair of double strand breaks. Given that Exo1 also participates in DNA replication and mismatch repair, here we test whether SWR-C influences DNA replication fidelity. We find that inactivation of SWR-C elevates the spontaneous mutation rate of a strain encoding a L612M variant of DNA polymerase (Pol) ?, with a single base mutation signature characteristic of lagging strand replication errors. However, this genomic instability does not solely result from reduced Exo1 function, because single base mutator effects are seen in both Exo1-proficient and Exo1-deficient pol3-L612M swr1? strains. The data are consistent with the possibility that incorporation of the H2A.Z variant by SWR-C may stimulate Exo1 activity, as well as enhance the fidelity of replication by Pol ?, the repair of mismatches generated by Pol ?, or both. PMID:25463393

  20. Development of a Binary Zn-Based Solder Alloy for Joining Wrought Magnesium Alloy AZ31B

    NASA Astrophysics Data System (ADS)

    Ma, Li; Long, Weimin; Qiao, Peixin; He, Dingyong; Li, Xiaoyan

    2013-01-01

    In the present article, the wrought magnesium alloy AZ31B sheets were soldered by means of high-frequency induction heating device using a novel binary Zn-based solder alloy in argon gas shield condition. The interfacial microstructure, phase constitution, and fracture morphology of the soldered joint were studied. The microhardness and shear strength of the soldered joint were tested. The experimental results exhibit that ?-Mg solid solution and ?-MgZn phase were formed in soldering region. Moreover, the ?-Mg7Zn3 phase in the original Zn-based solder alloy disappeared completely after the soldering process due to the fierce alloying between the molten binary Zn-based solder alloy and the base metal AZ31B during soldering. Test results show that the shear strength of the soldered joint is 28 MPa. The fracture morphology of the soldered joint displays an intergranular fracture mode, and the crack originates from ?-Mg + ?-MgZn eutectoid structure. The interaction between the molten Zn-based solder alloy and the base metal AZ31B leads the Zn-based solder alloy to be transformed into Mg-based soldering metal during soldering.

  1. Corrosion fatigue behaviors of two biomedical Mg alloys - AZ91D and WE43 - In simulated body fluid.

    PubMed

    Gu, X N; Zhou, W R; Zheng, Y F; Cheng, Y; Wei, S C; Zhong, S P; Xi, T F; Chen, L J

    2010-12-01

    Magnesium alloys have been recently developed as biodegradable implant materials, yet there has been no study concerning their corrosion fatigue properties under cyclic loading. In this study the die-cast AZ91D (A for aluminum 9%, Z for zinc 1% and D for a fourth phase) and extruded WE43 (W for yttrium 4%, E for rare earth mischmetal 3%) alloys were chosen to evaluate their fatigue and corrosion fatigue behaviors in simulated body fluid (SBF). The die-cast AZ91D alloy indicated a fatigue limit of 50MPa at 10? cycles in air compared to 20MPa at 10? cycles tested in SBF at 37°C. A fatigue limit of 110MPa at 10? cycles in air was observed for extruded WE43 alloy compared to 40MPa at 10? cycles tested in SBF at 37°C. The fatigue cracks initiated from the micropores when tested in air and from corrosion pits when tested in SBF, respectively. The overload zone of the extruded WE43 alloy exhibited a ductile fracture mode with deep dimples, in comparison to a brittle fracture mode for the die-cast AZ91D. The corrosion rate of the two experimental alloys increased under cyclic loading compared to that in the static immersion test. PMID:20656074

  2. Cities to Play: Outlining Competitive Profiles for European Cities

    Microsoft Academic Search

    Valeria Minghetti; Federica Montaguti

    \\u000a Visiting cities is an ever-growing tourism activity in Europe.Also thanks to the enlargement of the European Community, urban\\u000a tourism flows are expanding at a faster rate than tourism in general (ETC, 2008). Traditional cities are cities that were not created for tourism development and where tourism has established itself within\\u000a the changing economic, social and cultural environment.Tourism activities interact with

  3. BIG CITY, BIG TURNOUT? ELECTORAL PARTICIPATION IN AMERICAN CITIES

    Microsoft Academic Search

    NEAL CAREN

    2007-01-01

    This article seeks to describe and explain variation in voter turnout in American big city municipal elections using data from 332 mayoral elections in 38 large U.S. cities over 25 years. In my cross-sectional time-series analysis of turnout in mayoral elections, I find that city- level demographic factors are only weakly correlated with turnout. By contrast, institutional and campaign factors

  4. CityGML - Interoperable semantic 3D city models

    NASA Astrophysics Data System (ADS)

    Gröger, Gerhard; Plümer, Lutz

    2012-07-01

    CityGML is the international standard of the Open Geospatial Consortium (OGC) for the representation and exchange of 3D city models. It defines the three-dimensional geometry, topology, semantics and appearance of the most relevant topographic objects in urban or regional contexts. These definitions are provided in different, well-defined Levels-of-Detail (multiresolution model). The focus of CityGML is on the semantical aspects of 3D city models, its structures, taxonomies and aggregations, allowing users to employ virtual 3D city models for advanced analysis and visualization tasks in a variety of application domains such as urban planning, indoor/outdoor pedestrian navigation, environmental simulations, cultural heritage, or facility management. This is in contrast to purely geometrical/graphical models such as KML, VRML, or X3D, which do not provide sufficient semantics. CityGML is based on the Geography Markup Language (GML), which provides a standardized geometry model. Due to this model and its well-defined semantics and structures, CityGML facilitates interoperable data exchange in the context of geo web services and spatial data infrastructures. Since its standardization in 2008, CityGML has become used on a worldwide scale: tools from notable companies in the geospatial field provide CityGML interfaces. Many applications and projects use this standard. CityGML is also having a strong impact on science: numerous approaches use CityGML, particularly its semantics, for disaster management, emergency responses, or energy-related applications as well as for visualizations, or they contribute to CityGML, improving its consistency and validity, or use CityGML, particularly its different Levels-of-Detail, as a source or target for generalizations. This paper gives an overview of CityGML, its underlying concepts, its Levels-of-Detail, how to extend it, its applications, its likely future development, and the role it plays in scientific research. Furthermore, its relationship to other standards from the fields of computer graphics and computer-aided architectural design and to the prospective INSPIRE model are discussed, as well as the impact CityGML has and is having on the software industry, on applications of 3D city models, and on science generally.

  5. Investigation of the gas-jet ejector in KamAZ trucks

    SciTech Connect

    Shkret, L.Y.; Berezea, A.I.; Lobkov, A.N.

    1984-03-01

    This article considers the possibility of using gas-jet vacuum pumps in tank trucks for transporting liquids (water) at drilling sites. The discharge system of the KamAZ trucks can be reliably sealed by an engine brake, an important prerequisite of reliable operation of a gas-jet ejector that is switched on when the tank is being filled. The ejector consists of a housing, a Laval nozzle, a front wall with cylindrical neck, a tin-plate diffuser, an air supply pipe, and a flange for attaching the ejector to the flange of the exhaust muffler of the truck. The gas-jet ejectors are driven by the exhaust gas (EG) of the trucks. The dependences of the EG flow rate, fuel expenditure, EG temperature ahead of the ejector, and the rotational frequency of the engine crankshaft on the diameter at different EG pressures. It is recommended that gas-jet ejectors be used on series produced tank trucks instead of rotary vacuum pumps with mechanical drive.

  6. Effects of Compression-Pass on Microstructure and Mechanical Properties of AZ80 Alloy

    NASA Astrophysics Data System (ADS)

    Meng, Mu; Zhao, Xi; Zhang, Zhimin; Qiang, Wang

    2014-09-01

    In the present work, as-homogenized AZ80 alloy was subjected to the multi-pass compression at the same total compression strain and different compression passes. The effects of compression-pass on microstructure and mechanical properties were investigated. Results show that the intermittent reheating stage during the multi-pass compression process plays an important role in the microstructure evolution. During the intermittent reheating process, the fine grains in the duplex-grain microstructure generated by partial dynamic recrystallization grow rapidly, which lead to the increase of the average grain size and the decrease of the difference in grain size between the coarse and fine grains. This phenomenon is more obvious by the increase of the intermittent reheating stage. It finds that the hardness mainly depends on the average grain size, and the value decreases with the increase of the average grain size. However, the ultimate tensile strength and elongation mainly depends on the grain size distribution, and the better tensile properties can be obtained when the microstructure is more homogenous.

  7. Failure analysis of AZ31 magnesium alloy sheets based on the extended GTN damage model

    NASA Astrophysics Data System (ADS)

    Wang, Rui-ze; Chen, Zhang-hua; Li, Yu-jie; Dong, Chao-fang

    2013-12-01

    Based on the Gurson-Tvergaard-Needleman (GTN) model and Hill's quadratic anisotropic yield criterion, a combined experimental-numerical study on fracture initiation in the process of thermal stamping of Mg alloy AZ31 sheets was carried out. The aim is to predict the formability of thermal stamping of the Mg alloy sheets at different temperatures. The presented theoretical framework was implemented into a VUMAT subroutine for ABAQUS/EXPLICIT. Internal damage evolution due to void growth and coalescence developed at different temperatures in the Mg alloy sheets was observed by scanning electron microscopy (SEM). Moreover, the thermal effects on the void growth, coalescence, and fracture behavior of the Mg alloy sheets were analyzed by the extended GTN model and forming limit diagrams (FLD). Parameters employed in the GTN model were determined from tensile tests and numerical iterative computation. The distribution of major and minor principal strains in the specimens was determined from the numerical results. Therefore, the corresponding forming limit diagrams at different stress levels and temperatures were drawn. The comparison between the predicted forming limits and the experimental data shows a good agreement.

  8. Histone variant H2A.Z and RNA polymerase II transcription elongation.

    PubMed

    Santisteban, Maria Soledad; Hang, Mingda; Smith, M Mitchell

    2011-05-01

    Nucleosomes containing histone variant H2A.Z (Htz1) serve to poise quiescent genes for activation and transcriptional initiation. However, little is known about their role in transcription elongation. Here we show that dominant mutations in the elongation genes SPT5 and SPT16 suppress the hypersensitivity of htz1? strains to drugs that inhibit elongation, indicating that Htz1 functions at the level of transcription elongation. Direct kinetic measurements of RNA polymerase II (Pol II) movement across the 9.5-kb GAL10p-VPS13 gene revealed that the elongation rate of polymerase is 24% slower in the absence of Htz1. We provide evidence for two nonexclusive mechanisms. First, we observed that both the phospho-Ser2 levels in the elongating isoform of Pol II and the loading of Spt5 and Elongator over the GAL1 open reading frame (ORF) depend on Htz1. Second, in the absence of Htz1, the density of nucleosome occupancy is increased over the GAL10p-VPS13 ORF and the chromatin is refractory to remodeling during active transcription. These results establish a mechanistic role for Htz1 in transcription elongation and suggest that Htz1-containing nucleosomes facilitate Pol II passage by affecting the correct assembly and modification status of Pol II elongation complexes and by favoring efficient nucleosome remodeling over the gene. PMID:21357739

  9. Rate sensitivity and tension-compression asymmetry in AZ31B magnesium alloy sheet.

    PubMed

    Kurukuri, Srihari; Worswick, Michael J; Ghaffari Tari, Dariush; Mishra, Raja K; Carter, Jon T

    2014-05-13

    The constitutive response of a commercial magnesium alloy rolled sheet (AZ31B-O) is studied based on room temperature tensile and compressive tests at strain rates ranging from 10(-3) to 10(3)?s(-1). Because of its strong basal texture, this alloy exhibits a significant tension-compression asymmetry (strength differential) that is manifest further in terms of rather different strain rate sensitivity under tensile versus compressive loading. Under tensile loading, this alloy exhibits conventional positive strain rate sensitivity. Under compressive loading, the flow stress is initially rate insensitive until twinning is exhausted after which slip processes are activated, and conventional rate sensitivity is recovered. The material exhibits rather mild in-plane anisotropy in terms of strength, but strong transverse anisotropy (r-value), and a high degree of variation in the measured r-values along the different sheet orientations which is indicative of a higher degree of anisotropy than that observed based solely upon the variation in stresses. This rather complex behaviour is attributed to the strong basal texture, and the different deformation mechanisms being activated as the orientation and sign of applied loading are varied. A new constitutive equation is proposed to model the measured compressive behaviour that captures the rate sensitivity of the sigmoidal stress-strain response. The measured tensile stress-strain response is fit to the Zerilli-Armstrong hcp material model. PMID:24711496

  10. Study on Pressurized Solidification Behavior and Microstructure Characteristics of Squeeze Casting Magnesium Alloy AZ91D

    NASA Astrophysics Data System (ADS)

    Han, Zhiqiang; Pan, Haowei; Li, Yanda; Luo, Alan A.; Sachdev, Anil K.

    2015-02-01

    Squeeze casting technology for magnesium alloys has a great application potential in automobile manufacturing and has received increasing attention from both academic and industrial communities. In this study, the pressurized solidification behavior of magnesium alloy AZ91D in squeeze casting process was investigated using computer-aided cooling curve analysis (CA-CCA). It was found that the applied pressure increased both the start and end temperatures of primary ?-Mg formation but had little effect on the sizes of temperature ranges. Moreover, the applied pressure increased the start temperature and decreased the end temperature of eutectic reaction during the solidification, resulting in a larger temperature range of eutectic reaction compared with solidification under atmospheric pressure. The grains were remarkably refined, and the eutectic fraction increased with increasing applied pressure. The dendritic microstructure with a larger secondary dendrite arm spacing (SDAS) was observed under a higher applied pressure at the central part of the experimental casting. By correlating the CA-CCA and SDAS data, it was found that SDAS and the cooling rate at the maximum ?-Mg growth could be fit into the power law equation in classic solidification theories.

  11. Time Dependent Magnesium AZ31B Behavior: Experimental and Physically based Modeling Investigation

    NASA Astrophysics Data System (ADS)

    Rodriguez, A. K.; Ayoub, G.; Kridli, G.; Zbib, H.

    The need to produce vehicles with improved fuel efficiency and reduced emissions has led the automotive industry to consider use of “lightweighting” materials in the construction of automotive body and chassis systems. For automotive body structures and closure panel applications, mostly made of sheet, aluminum alloys are being introduced due to their lower densities and relatively high specific strengths, as well as their compatibility with the traditional manufacturing process that are used with steel. However, interest has been increasingly focusing on the use of sheet magnesium in the manufacturing of panels and structural components, since its density is about 40% lower compared to aluminum. Accordingly, the objectives of this study are to investigate the evolution of microstructure during thermo-mechanical processing of twin-roll cast AZ31B alloys sheets, and to examine the mechanical properties of the alloy under superplastic conditions. The rate dependent crystal plasticity model have been used and integrated using an explicit model was coupled with the Taylor polycrystal model in the aim to capture the overall behavior of our studied material.

  12. Mechanical and corrosion properties of Al/Ti film on magnesium alloy AZ31B

    NASA Astrophysics Data System (ADS)

    Zeng, Rong-Chang; Jiang, Ke; Li, Shuo-Qi; Zhang, Fen; Cui, Hong-Zhi; Han, En-Hou

    2015-03-01

    Preparation of titanium film on magnesium substrate faces a challenge due to non-Fickian inter-diffusion between titanium and magnesium. Aluminum can build a bridge between titanium and magnesium. Al/Ti duplex coatings were deposited on magnesium alloy AZ31B using magnetron sputtering (MS). The low temperature diffusion bonding behavior of the Mg/Al/Ti coating was investigated through SEM and its affiliated EDS. The phase structure and critical load of the coatings were examined by means of XRD and scratch tests, respectively. The results demonstrated that the bonding strength was significantly improved after a post heat treatment (HT) at a temperature of 210°C. The diffusion mechanism of the interfaces of Mg/Al and Al/Ti in the coating was discussed based on the analysis of formation energy of vacancies and diffusion rates. The Al/Ti dual layer enhanced the corrosion resistance of the alloy. And the HT process further increased the corrosion resistance of the coated alloy. This result implies that a post HTat a lower temperature after MS is an effective approach to enhance the bonding strength and corrosion resistance of the Al/Ti film on Mg alloys.

  13. High-Speed Rolling of AZ31 Magnesium Alloy Having Different Initial Textures

    NASA Astrophysics Data System (ADS)

    Onuki, Yusuke; Hara, Kenichiro; Utsunomiya, Hiroshi; Szpunar, Jerzy A.

    2015-02-01

    It is known that magnesium alloys can be rolled up to a large thickness reduction and develop a unique texture when the rolling speed is high (>1000 m/min). In order to understand the texture formation mechanism during high-strain-rate deformation, high-speed rolling of AZ31 magnesium alloy samples having different initial textures was conducted. The main components of the textures after the rolling were the RD-split basal, which consisted of 10°-20° inclining basal poles from the normal direction toward the rolling direction of the sheet, regardless of the different initial textures. With preheating at 473 K, all the samples were rolled without cracking while all were cracked when preheating was not applied. The optical micrographs and EBSD measurements showed a significant amount of twins and the cracks that developed along the shear bands consisted with laminated twins. Based on the texture simulation using the visco-plastic self-consistent model, it is concluded that the rapid development of the RD-split basal component from the initial basal alignment along the transverse direction was attributable to the tension twinning, The effect of the initial texture on the crack formation can be explained by the activation of the twinning system.

  14. THE AzTEC/SMA INTERFEROMETRIC IMAGING SURVEY OF SUBMILLIMETER-SELECTED HIGH-REDSHIFT GALAXIES

    SciTech Connect

    Younger, Joshua D.; Fazio, Giovanni G.; Huang Jiasheng; Ashby, Matthew L. N.; Gurwell, Mark A.; Petitpas, Glen R.; Wilner, David J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Yun, Min S.; Wilson, Grant W.; Scott, Kimberly S.; Austermann, Jason; Perera, Thushara [Astronomy Department, University of Massachusetts, Amherst, MA 01003 (United States); Peck, Alison B. [Joint ALMA Office, El Golf 40, Las Condes, Santiago 7550108 (Chile); Hughes, David H.; Aretxaga, Itziar [Instituto Nacional de AstrofIsica, Optica y Electronica (INAOE), Tonantzintla, Peubla (Mexico); Kim, Sungeun [Astronomy and Space Sciences Department, Sejong University, 98 Kwangjin-gu, Kunja-dong, Seoul 143-747 (Korea, Republic of); Lowenthal, James D., E-mail: jyounger@ias.ed [Astronomy Department, Smith College, Clark Science Center, Northampton, MA 01060 (United States)

    2009-10-10

    We present results from a continuing interferometric survey of high-redshift submillimeter galaxies (SMGs) with the Submillimeter Array, including high-resolution (beam size approx2 arcsec) imaging of eight additional AzTEC 1.1 mm selected sources in the COSMOS field, for which we obtain six reliable (peak signal-to-noise ratio (S/N) >5 or peak S/N >4 with multiwavelength counterparts within the beam) and two moderate significance (peak S/N >4) detections. When combined with previous detections, this yields an unbiased sample of millimeter-selected SMGs with complete interferometric follow up. With this sample in hand, we (1) empirically confirm the radio-submillimeter association, (2) examine the submillimeter morphology-including the nature of SMGs with multiple radio counterparts and constraints on the physical scale of the far infrared-of the sample, and (3) find additional evidence for a population of extremely luminous, radio-dim SMGs that peaks at higher redshift than previous, radio-selected samples. In particular, the presence of such a population of high-redshift sources has important consequences for models of galaxy formation-which struggle to account for such objects even under liberal assumptions-and dust production models given the limited time since the big bang.

  15. Fragg Virus - Kinetic City

    NSDL National Science Digital Library

    American Association for the Advancement of Science (; )

    2008-04-17

    The Fragg Virus is a learning module centered learning the importance of systems; it is a part of the Kinetic City-Mission to Vearth site. In general this module is concerned with how different parts work within a system. The Fragg Virus module is equipped with a computer simulation mind game, creative writing exercises for independent study, and art-centered exercises, as well as lesson plans for hands on games and activities designed for a group. The focus of the activities is evolution and the features of an animal that helps the animal survive in its environment. Certain features explored are the giraffes neck, polar bears fir, and a birds beak.

  16. USA CityLink

    NSDL National Science Digital Library

    When Santa Claus comes to town this year he will be taking an entirely different route. He has decided to harness his reindeer and hop in his sleigh a little earlier than usual to spread his Christmas cheer over the Information Superhighway. Users will be able to access a customizable letter from Santa, the latest Polar weather conditions, some holiday recipes and a special Christmas greeting. They will also be able to preview exciting Christmas gifts and toys which can be ordered from St. Nick's virtual workshop. (USA CityLink).

  17. New York City Flyby

    NSDL National Science Digital Library

    Jesse Allen

    1999-04-09

    These scenes show Long Island, Long Island Sound, and Mannhattan Island with the metropolitan area of New York City as seen by the Landsat Thematic Mapper (TM) instrument. The shortwave infrared (TM band 5), infrared (TM band 4), and visible green (TM band 2) channels are displayed in the images as red, green, and blue respectively. In this combination, barren and-or recently cultivated land appears red to pink, vegetation appears green, water is dark blue, and artificial structures of concrete and asphalt appear dark grey or black.

  18. The dynamics of city formation.

    PubMed

    Henderson, J Vernon; Venables, Anthony J

    2009-04-01

    This paper examines city formation in a country whose urban population is growing steadily over time, with new cities required to accommodate this growth. In contrast to most of the literature there is immobility of housing and urban infrastructure, and investment in these assets is taken on the basis of forward-looking behavior. In the presence of these fixed assets cities form sequentially, without the population swings in existing cities that arise in current models, but with swings in house rents. Equilibrium city size, absent government, may be larger or smaller than is efficient, depending on how urban externalities vary with population. Efficient formation of cities with internalization of externalities involves local government intervention and borrowing to finance development. The paper explores the institutions required for successful local government intervention. PMID:25089087

  19. Constructing cities, deconstructing scaling laws

    PubMed Central

    Arcaute, Elsa; Hatna, Erez; Ferguson, Peter; Youn, Hyejin; Johansson, Anders; Batty, Michael

    2015-01-01

    Cities can be characterized and modelled through different urban measures. Consistency within these observables is crucial in order to advance towards a science of cities. Bettencourt et al. have proposed that many of these urban measures can be predicted through universal scaling laws. We develop a framework to consistently define cities, using commuting to work and population density thresholds, and construct thousands of realizations of systems of cities with different boundaries for England and Wales. These serve as a laboratory for the scaling analysis of a large set of urban indicators. The analysis shows that population size alone does not provide us enough information to describe or predict the state of a city as previously proposed, indicating that the expected scaling laws are not corroborated. We found that most urban indicators scale linearly with city size, regardless of the definition of the urban boundaries. However, when nonlinear correlations are present, the exponent fluctuates considerably. PMID:25411405

  20. Transient Liquid Phase Diffusion Bonding of Magnesium Alloy (Mg-AZ31) to Titanium Alloy (Ti-6Al-4V)

    NASA Astrophysics Data System (ADS)

    Atieh, Anas Mahmoud

    The magnesium alloy Mg-AZ31 and titanium alloy Ti-6Al-4V have physical characteristics and mechanical properties that makes it attractive for a wide range of engineering applications in the aerospace and automotive industries. However, the differences in melting temperature and coefficient of thermal expansion hinder the use of traditional fusion welding techniques. Transient liquid phase (TLP) bonding of magnesium alloy Mg-AZ31 and titanium alloy Ti-6Al- 4V was performed and different interlayer types and configurations were used to facilitate joint formation. The joining of these alloys using Ni foils was successful at a bonding temperature of 515°C, bonding pressure 0.2 MPa, for bonding time of 5 minutes. At the Ni/Mg-AZ31 bond interface, the formation of a eutectic liquid between Mg and Ni was observed. The formation of Mg2Ni and Mg3AlNi2 were identified along the bond interface resulting in an isothermally solidified joint. At the Ni/Ti-6Al-4V interface, the solid-state diffusion process results in joint formation. The use of double Ni-Cu sandwich joint resulted in further enhancement in joint formation and this produced joints with greater shear strength values. The configuration of Mg-AZ31/Cu- Ni/Ti-6Al-4V or Mg-AZ31/Ni-Cu/Ti-6Al-4V influence the mechanism of bonding and the type of intermetallics formed within the joint. The application of thin Ni electrodeposited coatings resulted in further enhancements of joint quality due to better surface-to-surface contact and a reduction in the formation of intermetallics at the joint. The effect of Cu nano-particles in the coatings was found to decrease the eutectic zone width and this resulted in an increase the shear strength of the joints. The highest shear strength of 69 MPa was possible with bonds made using coatings containing Cu nano-particle dispersion.