Sample records for bullhead city az

  1. 77 FR 36439 - Safety Zone; Bullhead City Regatta; Bullhead City, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-19

    ...safety zone on the navigable waters of the Colorado River in Bullhead City...is held on the navigable waters of the Colorado River in Bullhead City...safety zone would include the waters of the Colorado River between Davis...

  2. 76 FR 38568 - Safety Zone; Bullhead City Regatta, Bullhead City, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-01

    ...safety zone on the navigable waters of the Colorado River in Bullhead City...is held on the navigable waters of the Colorado River in Bullhead City...safety zone would include the waters of the Colorado River between Davis...

  3. 78 FR 34300 - Safety Zone; Bullhead City Regatta, Bullhead City, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-07

    ...safety zone on the navigable waters of the Colorado River in Bullhead City...is held on the navigable waters of the Colorado River in Bullhead City...safety zone would include the waters of the Colorado River between Davis...

  4. 78 FR 44011 - Safety Zone; Bullhead City Regatta; Bullhead City, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-23

    ...safety zone on the navigable waters of the Colorado River in Bullhead City...is held on the navigable waters of the Colorado River in Bullhead City...anchor in a portion of the waters of the Colorado River between Davis...

  5. 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...

  6. 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

    ...Firework Events on the Colorado River, between Davis Dam (Bullhead City, Arizona) and Headgate Dam (Parker, Arizona) within the San Diego Captain...Firework Events on the Colorado River, between Davis Dam (Bullhead City, Arizona) and Headgate...

  7. 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

    ...Firework Events on the Colorado River, between Davis Dam (Bullhead City, Arizona) and Headgate Dam (Parker, Arizona) within the San Diego Captain...Firework Events on the Colorado River, between Davis Dam (Bullhead City, Arizona) and Headgate...

  8. 78 FR 16823 - Proposed Establishment of Class E Airspace; Tuba City, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-19

    ...the Tuba City VHF Omni-Directional Radio Range Tactical Air Navigational Aid (VORTAC), Tuba City, AZ to facilitate vectoring...particularly helpful in developing reasoned regulatory decisions on the proposal. Comments are specifically...

  9. Environmental Tradeoffs in a Desert City: An Investigation of Water Use, Energy Consumption, and Local Air Temperature in Phoenix, AZ

    E-print Network

    Hall, Sharon J.

    Environmental Tradeoffs in a Desert City: An Investigation of Water Use, Energy Consumption tradeoffs between vegetation cover, microclimate temperature, and water and energy consumption. References, AZ CONCLUSION ˇ Research Observations: ˇ Water Consumption, Energy Use, Vegetation Cover

  10. Brown bullhead (Ameiurus nebulosus) skin carcinogenesis.

    PubMed

    Bunton, T E

    2000-06-01

    Alternative models using fish species have been tested in liver toxicity and carcinogenesis bioassays. Similar models have not been developed for skin. The brown bullhead (Ameiurus nebulosus) has shown potential as a model for skin carcinogenesis studies due to its sensitivity to environmental chemical pollutants. The present study is an initial morphologic and biochemical characterization of the normal and neoplastic brown bullhead skin to assess its suitability as a model of skin carcinogenesis. Brown bullhead were removed from Back River in the Chesapeake Bay region, an area historically polluted with heavy metals and polycyclic aromatic hydrocarbons. Histology, histochemistry, and electron microscopy were used to stage the morphologic development and progression of neoplasia in skin. The distribution of keratin, a family of structural proteins with altered expression in mammalian tumorigenesis, was analyzed with one and two dimensional gel electrophoresis and nitrocellulose blots of extracts from normal skin. Keratin expression in skin and other organs was also assessed with immunohistochemistry using AE1, AE3, and PCK 26 antibodies, and the proliferation index in skin and neoplasms with PCNA antibody. Skin lesions appeared to progress from hyperplasia through carcinoma, and the proliferation index was increased in papilloma. Also in papilloma, intercellular interdigitations appeared increased and desmosomes decreased which may in future studies correlate with changes in expression of other molecular markers of neoplastic progression. Both Type I and Type II keratin subfamilies were detected in skin using gel electrophoresis with the complimentary keratin blot-binding assay. For further development of the brown bullhead model, future studies can compare and relate these baseline data to alterations in expression of keratin and other markers in fish neoplasms and to molecular events which occur in man. PMID:10930121

  11. Temperature-dependent Index of Mitotic Interval (?0) for Chromosome Manipulation in Korean Bullhead, Pseudobagrus fulvidraco

    PubMed Central

    Lim, Sang Gu; Han, Hyoung Kyun; Gil, Hyun Woo; Park, In-Seok

    2012-01-01

    Korean bullhead (Pseudobagrus fulvidraco) was collected from the Kum River areas of Kangkyung-eup, Nonsan city, Chungcheongnam-do, Korea, from April to June, 2012 and was fertilized in order to observe egg development and temperature-related cleavage rates and mitotic intervals (?0). The fertilized eggs were separative, demersal and light yellowish with 1.5ą0.06 mm in diameter, and did not contain oil globules. The first cleavage stages were 90 min, 80 min, 60 min and 50 min at 21°C , 24°C , 27°C and 30°C , respectively. At higher temperatures, eggs developed faster and underwent further identical development. For Korean bullhead, ?0 were 33.4ą2.08 min at 21°C, 31.5ą3.06 min at 24°C, 28.1ą2.11 min at 27°C and 26.4ą3.35 min at 30°C . There were strong negative correlations between the ?0 and water temperatures at all points studied (Y= 1.13X+58.15, R2=0.98, n=30, where Y is ?0 and X is temperature). The results obtained in this work will be helpful for chromosome manipulation by use of cleavage frequency data and ?0 data in Korean bullhead. PMID:25949107

  12. 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...

  13. Phoenix, AZ, USA

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The city of Phoenix, AZ (33.5N, 112.0W) can be seen in good detail in this color infrared scene. Situated among truck crop agriculture fields, the color infrared photo depicts the vegetated fields as shades of red making the agriculture stand out in this desert environment. To the east, Lake Theodore Roosevelt and dam can be easily seen.

  14. 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 ˇ ˇ . ˇ . 2. Mean first year survival rates of bluegills (Lepomis macrochirus) and black bullheads (Ictalurus

  15. 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

  16. 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

  17. In vitro response of the brown bullhead catfish cell line, BB, to aquatic pollutants

    Microsoft Academic Search

    N. Martin-Alguacil; H. Babich; D. W. Rosenberg; E. Borenfreund

    1991-01-01

    Established cell lines from brown bullhead catfish (BB) and rainbow trout (RTG-2) and primary cultures of cells derived from gill, fin, and gonad tissues from brown bullhead catfish were evaluated for use as bioindicators in the neutral red cytotoxicity assay. The BB and RTG-2 cells were compared after a 1 day exposure to chlorinated pesticides and after a 6-day exposure

  18. 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, ...

  19. 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 ...

  20. Spatial distribution of Atlantic salmon parr ( Salmo salar L.) and bullhead ( Cottus gobio L.) in lotic and lentic habitats of a diversified watercourse in northern Fennoscandia

    Microsoft Academic Search

    L. Jřrgensen; P.-A. Amundsen; H.-M. Gabler; M. Halvorsen; J. Erkinaro; E. Niemelä

    1999-01-01

    In 1979, bullheads (Cottus gobio L.) were registered for the first time in the River Utsjoki (70°N, 27°E), a large tributary of the River Tana, which is one of the most important Atlantic salmon (Salmo salar L.) rivers in the world. The bullhead was probably introduced into the river by man. The occurrence of bullheads in the River Utsjoki has

  1. 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.

  2. 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.

  3. 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...

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

    PubMed

    Blazer, Vicki S; Fournie, John W; Wolf, Jeffrey C; Wolfe, Marilyn J

    2006-09-14

    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. PMID:17067070

  5. 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.

  6. 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.

  7. 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; Skarphéđinsdóttir, 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.

  8. 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,...

  9. 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.

  10. 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.

  11. Temporal and spatial patterns in tumour prevalence in brown bullhead Ameiurus nebulosus (Lesueur) in the tidal Potomac River watershed (USA).

    PubMed

    Pinkney, A E; Harshbarger, J C; Rutter, M A

    2014-10-01

    For two decades, fish tumour surveys have been used to monitor habitat quality in the Chesapeake Bay (USA) watershed. Tributaries with sediments contaminated with polynuclear aromatic hydrocarbons (PAHs), known to cause liver neoplasia, were frequently targeted. Here, we compare surveys in brown bullhead Ameiurus nebulosus conducted in 2009-2011 in the tidal Potomac River watershed (including the Anacostia River) with previous surveys. Using logistic regression, we identified length and sex as covariates for liver and skin tumours. We reported a statistically significant decrease in liver tumour probabilities for standardized 280 mm Anacostia bullheads between the 1996 and 2001 samplings (merged collections: female-77.5%, male-43.0%) and 2009-2011 (female-42.2%, male-13.6%). However, liver tumour prevalence in bullheads from the Anacostia, Potomac River (Washington, DC) and Piscataway Creek (17 km downriver) was significantly higher than that for Chesapeake Bay watershed reference locations. The causes of skin tumours in bullheads are uncertain, requiring further research. The similar liver tumour prevalence in these three locations suggests that the problem is regional rather than restricted to the Anacostia. To monitor habitat quality and the success of pollution control actions, we recommend conducting tumour surveys on a 5-year cycle coordinated with sediment chemistry analyses. PMID:24974857

  12. HISTORICAL MONITORING OF BIOMARKERS OF PAH EXPOSURE OF BROWN BULLHEAD IN THE REMEDIATED BLACK RIVER AND THE CUYAHOGA RIVER, OHIO

    EPA Science Inventory

    Biomarkers of exposure to chemical contamination were measured in brown bullhead from a heavily PAH contaminated section of the Black River, Ohio, during and immediately after remedial sediment dredging in 1990-1991, and in follow-up visits in 1993 and 1998. Biomarker levels of ...

  13. ISOFORMS OF APOLIPOPROTEIN A-I IN THE SERUM OF BROWN BULLHEADS (AMEIURUS NEBULOSUS) WITH LIVER CANCER

    EPA Science Inventory

    1. Serum samples from 10 tumor-bearing (all fish with cholangiocellular carcinomas, some with both cholangio- and hepatocellular carcinomas) and 8 non-tumor-bearing brown bullheads were analyzed by 2D-PAGE. . Two isoforms of Apolipoproteins A-1 with a molecular weight of 28 kDA w...

  14. 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.

  15. Synchronous fluorometric measurement of metabolites of polycyclic aromatic hydrocarbons in the bile of brown bullhead

    SciTech Connect

    Lin, E.L.C.; Cormier, S.M. (Environmental Protection Agency, Cincinnati, OH (United States). Environmental Monitoring Systems Lab.); Racine, R.N.

    1994-05-01

    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. For comparison, fish biliary benzo[a]pyrene (B[a]P) metabolites were also measured by HPLC/fluorescent detection (HPLC/F). Both methods showed that concentrations of biliary PAH metabolites of fish collected in polluted rivers were significantly higher than those collected from reference rivers. Concentrations biliary metabolites of fish caught in the Black River were five to 20 times greater than those collected in Old Woman Creek by SFS and three to five times greater by HPLC/F. Fish from the Cuyahoga River had four to 24 times more biliary PAH metabolites than fish from Old Woman Creek, measured by SFS, and five to 10 times more, measured by HPLC/F. Brown bullhead from the Toussaint River had fewer PAH metabolites than fish from Old Woman Creek. Correlation analyses of the two sets of data obtained by SFS and HPLC/F showed significance by both Pearson's sample correlation and Spearman's rank correlation. This study indicates that pyrene-type metabolites determined by SFS can be used to estimate B[a]P-type metabolites in fish bile. SFS appears to be a highly sensitive method for detecting PAH metabolites and, because of its simplicity, a cost-efficient method for screening large numbers of samples for exposure to PAHs in fish.

  16. In vitro response of the brown bullhead catfish cell line, BB, to aquatic pollutants.

    PubMed

    Martin-Alguacil, N; Babich, H; Rosenberg, D W; Borenfreund, E

    1991-01-01

    Established cell lines from brown bullhead catfish (BB) and rainbow trout (RTG-2) and primary cultures of cells derived from gill, fin, and gonad tissues from brown bullhead catfish were evaluated for use as bioindicators in the neutral red cytotoxicity assay. The BB and RTG-2 cells were compared after a 1 day exposure to chlorinated pesticides and after a 6-day exposure to various polycyclic aromatic hydrocarbons. The BB cells were more sensitive to both classes of chemicals. The sequence of toxicity for the BB cells was 4,4'-DDD. 4,4'-DDT greater than aldrin, 4,4'-DDE and 7,12-dimethylbenz(a)anthracene (DMBA) greater than 3-hydroxybenzo(a)pyrene (3-OH-B(a)P) greater than benzo(a)pyrene (B(a)P). For the RTG-2 cells, the sequence was aldrin greater than 4,4'-DDD greater than 4,4'-DDT greater than 4,4'-DDE and 3-OH-B(a)P greater than DMBA greater than B(a)P. The BB cells were also sensitive to benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)anthracene, and trans-7,8-dihydro-7,8-dihydroxybenzo(a)pyrene. The responses of BB and RTG-2 cells were compared with those of primary cultures after a 1 day exposure to B(a)P. After 1 day of exposure, the RTG-2 cells and primary cultures were more sensitive than the BB cells to B(a)P. Apparently, after 1 day of incubation the RTG-2 and primary cells metabolized greater amounts of B(a)P to cytotoxic metabolites, than did the BB cells. However, by 6 days of incubation, the BB cells were more sensitive to B(a)P than were the RTG-2 cells. A 6-day exposure to B(a)P was not performed with the primary cell cultures. PMID:1996902

  17. AZ OLVASÁS ÉS A METAKOGNÍCIÓ KAPCSOLATA ISKOLÁSKORBAN

    Microsoft Academic Search

    MAGYAR PEDAGÓGIA; Tarkó Klára

    A metakogníció általános jellemzése után szó esik a feladatvégzéshez szükséges stra- tégiákról, azok elsajátíttatásáról különösen az olvasástanításban, a metakogníció vizsgá- lati módszereinek gyakorlati alkalmazásáról és az olvasás folyamatának modelljeir?l. Az olvasástanulás el?tti életszakasz kognitív jellemz?i sokat elárulnak a gyerekek kés?bbi olvasási teljesítményér?l. Az olvasástanítás során azonban számos probléma felmerülhet, amelyek egyaránt következhetnek a tanulók képességeib?l és az oktatás hibáiból is.

  18. 77 FR 62216 - Proposed Foreign-Trade Zone-Eloy, AZ Comment Period on New Evidence

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-12

    ...35-2011] Proposed Foreign-Trade Zone--Eloy, AZ Comment Period on New Evidence On...Foreign-Trade Zones (FTZ) Board by the City of Eloy, Arizona, requesting authority to establish...on new evidence submitted by the City of Eloy on July 31, 2012, on which there...

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

    SciTech Connect

    Baumann, P.C. [Ohio State Univ., Columbus, OH (United States); Harshbarger, J.C. [Smithsonian Institution, Washington, DC (United States)

    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. 21 refs., 4 tabs.

  20. 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.

  1. A virtuális navigáció és az ultrahangos kontrasztanyagok kombinált alkalmazása: az ultrahang-technika legújabb vívmányai az intervenciós radiológia szolgálatában

    Microsoft Academic Search

    Harmat Zoltán; Battyány István

    2007-01-01

    A radiológiai diagnosztika és az intervenciós radio- lógiai beavatkozások tervezése, végrehajtása során a leggyakrabban alkalmazott képalkotó módszer az ultra- hang. Számos esetben mégis nehézség adódik abból, hogy egy, az egyéb képalkotó modalitások által kimuta- tott elváltozás így nehezen vagy csak alig azonosítható. A virtuális navigációs rendszer ötvözi a különbözô kép- alkotó technikák elônyös tulajdonságait, így ultrahang- vezérelt intervenciós radiológiai beavatkozás

  2. 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.

  3. 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.

  4. 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.

  5. Pigmented macrophage aggregates as a biomarker of oxidative damage in yellow bullhead catfish, Ameiurus natalis

    SciTech Connect

    McCreedy, C.D.; HoganEsch, H.; Turek, J. [Purdue Univ., W. Lafayette, IN (United States); Jagoe, C.H. [Savannah River Ecology Lab., Aiken, SC (United States)

    1995-12-31

    Pigmented macrophage aggregates (PMs) occur when peroxidized lipids resulting from oxidative damage in tissues are scavenged by macrophages. Ionizing radiation causes oxidative damage, so the authors evaluated PMs as a biomarker in the pronephros of yellow bullheads (Ameiurus natalis) inhabiting Pond B, Savannah River Site, SC, a reservoir contaminated with low levels of {sup 137}Cs. ANOVA, ANCOVA, and stepwise regression were used to relate the mean number of PMs, per 0.15 mm{sup 2} of tissue section, to fish sex (females: N = 61; males: N = 84), age (1--6 yrs), body-condition, and muscle {sup 137}Cs concentration. Mean pronephric PMs differed by six and with fish muscle {sup 137}Cs concentration. Among males, PMs were positively correlated with fish age and {sup 137}Cs. In females, PMs were also correlated with fish age and {sup 137}Cs. ANCOVA, with age as covariate, affirmed that sex and muscle {sup 137}Cs were significantly associated with the mean number of pronephric PMs. Using stepwise regression, the interaction of age and {sup 137}Cs concentration was most strongly associated with pronephric PMs in males. Among females, the product of age, body-condition, and {sup 137}Cs concentration was most strongly associated with pronephric PMs. The positive relationships between the number of pronephric PMs and {sup 137}Cs concentration suggest that oxidative damage related to long-term exposure to low-level radiation is detectable in these fish. Secondarily, these results demonstrate the importance of considering covariates such as age and sex when evaluating effects of environmental contaminants.

  6. 76 FR 30907 - Proposed Foreign-Trade Zone-Eloy, AZ; Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-27

    ...35-2011] Proposed Foreign-Trade Zone--Eloy, AZ; Application An application has been...Zones Board (the Board) by the City of Eloy to establish a general-purpose foreign...covering approximately 918 acres in the Eloy (Pinal County), Arizona area:...

  7. NÉHÁNY SZEMÉLYES MOTÍVUM SZEREPE AZ ÖNSZABÁLYOZÓ TANULÁSBAN

    Microsoft Academic Search

    MAGYAR PEDAGÓGIA; Molnár Éva; MTA-SZTE Képességkutató Csoport

    2003-01-01

    Az utóbbi id?ben a pedagógiai kutatás elméletében és gyakorlatában három f? tendencia vált hangsúlyossá: a tudás tartalmának átértelmezése, a tudás képességjelleg? kompo- nenseinek kiemelése és fejlesztése, illetve a tanulás nem-kognitív jelleg? tényez?inek hangsúlyozása (Csapó, 2002). Az ismeretek folyamatos átértékel?dése, változása, a tar- talmi tudás gyors elévülése eredményeképpen fontossá vált az ismeretekbe ágyazott ké- pességek tanítása is, ugyanakkor a tanulási igény

  8. 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

  9. 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

  10. Recommendations to design environmental monitoring in the European bullhead, Cottus sp., based on reproductive cycle and immunomarker measurement.

    PubMed

    Bado-Nilles, Anne; Villeret, Mélanie; Geffard, Alain; Palluel, Olivier; Blanchard, Christophe; Le Rohic, Cindy; Besson, Sylvain; Porcher, Jean-Marc; Minier, Christophe; Sanchez, Wilfried

    2015-06-30

    European bullhead is a relevant fish species to assess adverse effects of environmental stress on wild fish. Nevertheless, their complex reproductive cycle is very different between sites and could interfere with many physiological processes. Thus, prior to use biomarker to statute on environmental quality of rivers, we wanted to characterize reproductive profile (spawn number, GSI, gonad development). The major results demonstrated that the two types of reproductive cycle shown were strongly correlated to water temperature variation. In a second time, even if innate immunomarkers are highly relevant on biomonitoring program, hormonal variation seems to impact severely their responses. Thus, the link between reproductive status and immune activity (leucocyte distribution, cellular mortality, respiratory burst, phagocytosis activity) must also be study. Nonetheless, in the present work, immune capacities seems to be more correlated with season and environmental factors than reproduction. PMID:25599631

  11. 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.

  12. 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.

  13. 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.

  14. 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

    ...W; along the shoreline to 35°01?05? N, 114°38?20? W. 2. Rockets Over the River Sponsor Laughlin Tourism Committee. Event Description Fireworks Display Date First week in July. Location Laughlin, NV....

  15. Feeding strategies, resource utilisation and potential mechanisms for competitive coexistence of Atlantic salmon and alpine bullhead in a subArctic river

    Microsoft Academic Search

    Heidi-Marie Gabler; Per-Arne Amundsen

    2010-01-01

    We scrutinised the seasonal food-niche utilisation of river dwelling Atlantic salmon parr and alpine bullhead in order to\\u000a examine potential mechanisms that may facilitate coexistence of species with similar niches. Fish were sampled monthly during\\u000a the ice-free season, and diet composition and feeding strategy of the two species were compared by analyses of stomach contents.\\u000a The dietary niches and feeding

  16. AZ ISKOLAI TANULÁS: A LEGFRISSEBB EREDMÉNYEK ÉS A LEGFONTOSABB TENNIVALÓK

    Microsoft Academic Search

    MAGYAR PEDAGÓGIA; Erik De Corte

    A XXI. század elején a pedagógia feladata az lenne, hogy felkészítse a diákokat a napja- ink komplex és állandóan változó társadalmában szükségessé vált egész életen át tartó tanulásra. A jelek ugyanakkor az mutatják, hogy az iskolák pillanatnyilag nem túl si- keresek ebben a tekintetben. Az European Round Table of Industrialists (ERT (Európai Ipari Kerekasztal), 1995) \\

  17. 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

  18. Monitoring exposure of brown bullheads and benthic macroinvertebrates to sediment contaminants in the Ashtabula river before, during, and after remediation.

    PubMed

    Meier, John R; Lazorchak, James M; Mills, Marc; Wernsing, Paul; Baumann, Paul C

    2015-06-01

    In 2007, approximately 420?500 cubic meters of contaminated sediment were removed from the Ashtabula River by dredging. The primary objective of the present study was to monitor contaminant exposure in fish and macroinvertebrates before, during, and after dredging. This was done by measuring tissue concentrations of polychlorinated biphenyl (PCB) and polycyclic aromatic hydrocarbon (PAH) in brown bullhead catfish (Ameriurus nebulosa) and in benthic macroinvertebrates, assessing changes in DNA damage in fish liver and blood, and scoring external and histopathological lesions and anomalies in the fish. In surficial sediment PCBs and PAHs were also quantified in conjunction with the biological sampling. The results show a significant reduction in contaminant levels in both fish and macroinvertebrates following dredging, indicating the effectiveness of the remediation in reducing exposure of biota to the primary contaminants of concern. Similarly, DNA damage levels in fish collected from the Ashtabula River significantly declined following dredging; however, a similar reduction in DNA damage over time was seen in fish collected from a reference site (Conneaut Creek), making interpretation difficult. Macroinvertebrate PCB concentrations were reflective of the sediment concentrations in the areas where Hester-Dendy samplers were deployed for macroinvertebrate collection. The present study demonstrates that these methods can be used to evaluate and assess the effectiveness of remediation techniques at contaminated sediment sites. Environ Toxicol Chem 2015;34:1267-1276. Š 2015 SETAC. PMID:25565098

  19. Martin Elvis, Interferometry Workshop, Tucson AZ Nov 2006 Imaging Quasars

    E-print Network

    Elvis, Martin

    Martin Elvis, Interferometry Workshop, Tucson AZ Nov 2006 Imaging Quasars with Interferometry Martin Elvis Harvard-Smithsonian Center for Astrophysics #12;Martin Elvis, Interferometry Workshop Galactic Nuclei) are just lower luminosity quasars) #12;Martin Elvis, Interferometry Workshop, Tucson AZ

  20. 76 FR 18378 - Amendment of Class E Airspace; Taylor, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-04

    ...10-AWP-19] Amendment of Class E Airspace; Taylor, AZ AGENCY: Federal Aviation Administration (FAA...SUMMARY: This action will amend Class E airspace at Taylor Airport, Taylor, AZ, to accommodate aircraft using the CAMBO...

  1. 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...

  2. 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…

  3. Waste Toolkit A-Z Bits & Bobs

    E-print Network

    Melham, Tom

    Waste Toolkit A-Z Bits & Bobs How can I recycle bits and bobs? Bits and bobs are the annoying). Science areas may be interested in donating plastic packaging that cannot be recycled through the normal: pipette packaging, tape rolls, plastic items, lids, CDs ­ the list is endless... How much does it cost

  4. 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 complete the Disposal of Hazardous Substances form which can be downloaded from the Safety Office website

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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.

  10. Assessment of Debris Flow Hazards, North Mountain, Phoenix, AZ

    NASA Astrophysics Data System (ADS)

    Reavis, K. J.; Wasklewicz, T. A.

    2014-12-01

    Urban sprawl in many western U.S. cities has expanded development onto alluvial fans. In the case of metropolitan Phoenix, AZ (MPA), urban sprawl has led to an exponential outward growth into surrounding mountainous areas and onto alluvial fans. Building on alluvial fans places humans at greater risk to flooding and debris flow hazards. Recent research has shown debris flows often supply large quantities of material to many alluvial fans in MPA. However, the risk of debris flows to built environments is relatively unknown. We use a 2D debris flow modeling approach, aided by high-resolution airborne LiDAR and terrestrial laser scanning (TLS) topographic data, to examine debris flow behavior in a densely populated portion of the MPA to assess the risk and vulnerability of debris flow damage to the built infrastructure. A calibrated 2D debris flow model is developed for a "known" recent debris flow at an undeveloped site in MPA. The calibrated model and two other model scenarios are applied to a populated area with historical evidence of debris flow activity. Results from the modeled scenarios show evidence of debris flow damage to houses built on the alluvial fan. Debris flow inundation is also evident on streets on the fan. We use housing values and building damage to estimate the costs assocaited with various modeled debris flow scenarios.

  11. 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...

  12. 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.

  13. 702AZ aging waste ventilation facility year 2000 test procedure

    SciTech Connect

    Winkelman, W.D.

    1998-07-22

    This test procedure was developed to determine if the 702AZ Tank Ventilation Facility system is Year 2000 Compliant. The procedure provides detailed instructions for performing the operations necessary and documenting the results. This verification procedure will document that the 702AZ Facility Systems are year 2000 compliant and will correctly meet the criteria established in this procedure.

  14. Digitális radiológia gyakorlati használata az OGYK-ban

    Microsoft Academic Search

    Barta H. Miklós; Berentey Ernô; Forrai Gábor

    2004-01-01

    Radiológiai osztályunkon 1999. szeptember óta a hagyományos felvételek és gasztroenterológiai vizs- gálatok célzott képei kizárólag foszforlemezre készül- nek. Két munkaállomás és számos képvisszanézô állo- más áll a radiológusok illetve klinikusok rendelkezésé- re. Az adatforgalom lebonyolítása szerveren keresztül történik, a hosszú távú adattárolás magneto-optikai le- mezeken. A távolabbi helyekkel való konzultáció lehe- tôsége adott. A CT-vizsgálatok és az átvilágítók anya- gának

  15. Warm incremental forming of magnesium alloy AZ31

    Microsoft Academic Search

    G. Ambrogio; L. Filice; G. L. Manco

    2008-01-01

    Industrial application of magnesium alloy AZ31 is dramatically increasing due to the very competitive mechanical strength vs. weight ratio. On the other hand, AZ31 is very difficult to be formed at room temperature. In this study incremental forming of the above material is taken into account, with particular reference to formability limits. The role of the main process parameters on

  16. Structural polymorphism in the L1 loop regions of human H2A.Z.1 and H2A.Z.2.

    PubMed

    Horikoshi, Naoki; Sato, Koichi; Shimada, Keisuke; Arimura, Yasuhiro; Osakabe, Akihisa; Tachiwana, Hiroaki; Hayashi-Takanaka, Yoko; Iwasaki, Wakana; Kagawa, Wataru; Harata, Masahiko; Kimura, Hiroshi; Kurumizaka, Hitoshi

    2013-12-01

    The histone H2A.Z variant is widely conserved among eukaryotes. Two isoforms, H2A.Z.1 and H2A.Z.2, have been identified in vertebrates and may have distinct functions in cell growth and gene expression. However, no structural differences between H2A.Z.1 and H2A.Z.2 have been reported. In the present study, the crystal structures of nucleosomes containing human H2A.Z.1 and H2A.Z.2 were determined. The structures of the L1 loop regions were found to clearly differ between H2A.Z.1 and H2A.Z.2, although their amino-acid sequences in this region are identical. This structural polymorphism may have been induced by a substitution that evolutionally occurred at the position of amino acid 38 and by the flexible nature of the L1 loops of H2A.Z.1 and H2A.Z.2. It was also found that in living cells nucleosomal H2A.Z.1 exchanges more rapidly than H2A.Z.2. A mutational analysis revealed that the amino-acid difference at position 38 is at least partially responsible for the distinctive dynamics of H2A.Z.1 and H2A.Z.2. These findings provide important new information for understanding the differences in the regulation and functions of H2A.Z.1 and H2A.Z.2 in cells. PMID:24311584

  17. 78 FR 3877 - Radio Broadcasting Services; Peach Springs, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-17

    ...RM-11687; DA 12-2072] Radio Broadcasting Services...Springs, AZ AGENCY: Federal Communications Commission. ACTION: Proposed...Subjects in 47 CFR Part 73 Radio, Radio broadcasting. Federal Communications Commission. Nazifa...

  18. 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/name #12;KU Student Profile Fall 2011 | University of Kansas 36° Kyou Email Blackboard Enroll & Pay KU Home

  19. Characterization of AZ91\\/alumina nanocomposite produced by FSP

    Microsoft Academic Search

    Ghader Faraji; Parviz Asadi

    2011-01-01

    The microstructures, wear property and micro-hardness of AZ91 Mg alloy\\/alumina particle reinforced nano-composite produced by friction stir processing (FSP) were investigated. The initial microstructures of the AZ91 were composed of irregularly distributed ?-phases (Al12Mg17), while the FSPed specimens were characterized by the homogeneous distribution of alumina particles, the recrystallized grain structure and the dissolution of ?-phase. The results showed an

  20. A C-type lectin isolated from the skin of Japanese bullhead shark (Heterodontus japonicus) binds a remarkably broad range of sugars and induces blood coagulation.

    PubMed

    Tsutsui, Shigeyuki; Dotsuta, Yuma; Ono, Ayaka; Suzuki, Masanari; Tateno, Hiroaki; Hirabayashi, Jun; Nakamura, Osamu

    2015-05-01

    The aim of this study was to determine the physiological role of skin lectins of the Japanese bullhead shark (Heterodontus japonicus). A skin extract was subjected to affinity chromatography using seven different sugars as ligands. Molecular mass and N-terminal amino acid sequence analyses indicated elution of the same protein by each of the seven respective cognate ligands from sugar affinity columns. The predicted amino acid sequence encoded by the cDNA of this protein [designated as H. japonicus C-type-lectin (HjCL)] identified it as a novel fish subgroup VII C-type lectin evolutionarily related to snake venom lectins. HjCL was predicted to bind to mannose because of the presence of a Glu-Pro-Asn (EPN) motif; however, haemagglutination inhibition assays and glycoconjugate microarray analysis demonstrated its binding to numerous structurally diverse sugars. Competitive sugar-binding assays using affinity chromatography indicated that HjCL bound multiple sugars via a common carbohydrate-recognition domain. The mRNA encoding HjCL was specifically detected in the skin, and immunohistochemical analysis detected its expression in uncharacterized large cells in the epidermis. HjCL agglutinated the bacterial pathogen Edwardsiella tarda and promoted immediate clotting of shark blood, indicating that HjCL is involved in host defence on the skin surface especially when the shark is injured and bleeds. PMID:25433861

  1. Caustic leaching of composite AZ-101/AZ-102 Hanford tank sludge

    SciTech Connect

    Rapko, B.M.; Wagner, M.J.

    1997-07-01

    To reduce the quantity (and hence the cost) of glass canisters needed for disposing of high-level radioactive wastes from the Hanford tank farms, pretreatment processes are needed to remove as much nonradioactive material as possible. This report describes the results of a laboratory-scale caustic leaching test performed on a composite derived from a combination of 241-AZ-101 and 241-AZ-102 Hanford Tank sludges. The goals of this FY 1996 test were to evaluate the effectiveness of caustic leaching on removing key components from the sludge and to evaluate the effectiveness of varying the free-hydroxide concentrations by incrementally increasing the free hydroxide concentration of the leach steps up to 3 {und M} free hydroxide. Particle-size analysis of the treated and untreated sludge indicated that the size and range of the sludge particles remained essentially unchanged by the caustic leaching treatment. Both before and after caustic leaching, a particle range of 0.2 {micro}m to 50 {micro}m was observed, with mean particle diameters of 8.5 to 9 {micro}m based on the volume distribution and mean particle diameters of 0.3 to 0.4 {micro}m based on the number distribution.

  2. 75 FR 57327 - Environmental Impact Statement; Pinal County, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-20

    ...Yavapai-Apache Nation, Salt River Project, Phoenix-Mesa Gateway Airport Authority, Town of Florence, City of Coolidge, City of Eloy, City of Queen Creek, Town of Gilbert, City of Mesa, City of Apache Junction, City of Casa Grande, Town of Marana,...

  3. 76 FR 3570 - Proposed Amendment of Class E Airspace; Taylor, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-20

    ...10-AWP-19] Proposed Amendment of Class E Airspace; Taylor, AZ AGENCY: Federal Aviation Administration (FAA...This action proposes to modify Class E airspace at Taylor Airport, Taylor, AZ. Controlled airspace is necessary to...

  4. 78 FR 78298 - Proposed Establishment of Class E Airspace; Phoenix, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-26

    ...Omni-Directional Radio Range Tactical Air Navigation Aid (VORTAC), Phoenix, AZ, to...developing reasoned regulatory decisions on the proposal. Comments are...the Phoenix VORTAC navigation aid, Phoenix, AZ. This action...

  5. Great Zoom into Tucson, AZ: Sabino Canyon

    NSDL National Science Digital Library

    Greg Shirah

    2003-06-10

    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.

  6. 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.

  7. 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 ...

  8. Revised 10/13AZ1221 COLLEGE OF AGRICULTURE

    E-print Network

    Wong, Pak Kin

    is an example of complete metamorphosis. There are four distinct stages in the life of a mosquito: egg, larva specialized mosquitoes). Mosquito larvae have a siphon at the tail end of the body (Fig. 3). The siphonRevised 10/13AZ1221 COLLEGE OF AGRICULTURE AND LIFE SCIENCES COOPERATIVE EXTENSION Mosquitoes

  9. 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 cups if they are made from PET or HDPE plastic (ask your supplier to confirm the type of plastic if you do not know). If the cups are made from any other type of plastic (see symbols below) they cannot

  10. 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- értelműen a magasabb árral jár együtt. Ez egyben azt is jelenti, hogy a költség-hatékonysági érték

  11. Economical toric spines via Cheeger's Inequality Bo'az Klartag

    E-print Network

    Alon, Noga

    Economical toric spines via Cheeger's Inequality Noga Alon Bo'az Klartag Abstract Let G = (Cd m cycle Cm. A spine (or an edge-spine) is a set of edges that intersects every nontrivial cycle. It is easy to see that there is a spine in G containing a fraction of O(d/m) of the edges. A recent result

  12. Economical toric spines via Cheeger's Inequality Bo'az Klartag

    E-print Network

    Shamir, Ron

    Economical toric spines via Cheeger's Inequality Noga Alon Bo'az Klartag Abstract Let G = (Cd m of the coordinates contains the full cycle Cm. A spine (or an edge-spine) is a set of edges that intersects (the set of edges of) every nontrivial cycle. It is easy to see that there is a spine in G containing a fraction

  13. 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

  14. Fabrication and characterization of AZ91\\/CNT magnesium matrix composites

    Microsoft Academic Search

    Yong-Ha Park; Yong-Ho Park; Ik-Min Park; Jeong-Jung Oak; Hisamichi Kimura; Kyung-Mox Cho

    2008-01-01

    Carbon Nano Tube (CNT) reinforced AZ91 metal matrix composites (MMC) were fabricated by the squeeze infiltrated method. Properties of magnesium alloys have been improved by impurity reduction, surface treatment and alloy design, and thus the usage for the magnesium alloys has been extended recently. However there still remain barriers for the adaption of magnesium alloys for engineering materials. In this

  15. 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

  16. 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

  17. 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 products such as used note pads, paper and cardboard files in the University Grundon recycling boxes. You can't recycle mixed materials that are made of non- recyclable plastic, such as plastic files

  18. 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 via Reclaim-IT, one of the largest companies in the UK dedicated to reusing and recycling empty laser in the office products industry throughout the UK. Reclaim-IT is a fully licensed Waste Carrier (Environment

  19. CESIUM REMOVAL FROM TANKS 241AN103 & 241SX105 & 241-AZ-101 & 241AZ-102 COMPOSITE FOR TESTING IN BENCH SCALE STEAM REFORMER

    Microsoft Academic Search

    DUNCAN JB; HUBER HJ

    2011-01-01

    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

  20. User Manual for the AZ-101 Data Acquisition System (AS-101 DAS)

    SciTech Connect

    BRAYTON, D.D.

    2000-02-17

    User manual for the TK AZ-101 Waste Retrieval System Data Acquisition System. The purpose of this document is to describe use of the AZ-101 Data Acquisition System (AZ-101 DAS). The AZ-101 DAS is provided to fulfill the requirements for data collection and monitoring as defined in Letters of Instruction (LOI) from Numatec Hanford Corporation (NHC) to Fluor Federal Services (FFS). For a complete description of the system, including design, please refer to the AZ-101 DAS System Description document, RPP-5572.

  1. ERPs and Domain Speci city: Beating a Straw Horse Seana Coulson

    E-print Network

    Coulson, Seana

    ERPs and Domain Speci city: Beating a Straw Horse Seana Coulson University of Arizona, Tucson, AZ and negative peaks known as the event-related brain potential (ERP). In the 1960s, it was well-known that the amplitude and latency of these peaks, or ``components'', in the ERP could be correlated with sensory aspects

  2. 2014 NIST SURF Universities City State/Province University of Alabama Tuscaloosa AL

    E-print Network

    2014 NIST SURF Universities City State/Province University of Alabama Tuscaloosa AL Alabama State Univ (2 students) Montgomery AL Arizona State Univ (3 students) Tempe AZ University Cal. Berkeley West Haven CT Yale University New Haven CT American University Washington DC University District

  3. 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.

  4. 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

    osztálya. Fiszerkeszti: Kálóczi Katalin fiigazgató-helyettes. Szerkeszti: Fábián Edit (fabian.edit@lib.elte.hu a nyilvántartásuk rendjéril az Eötvös Loránd Tudományegyetemen Elérheti: http://www.elte.hu/dokumentumok/rektut Az módszertani osztály ad felvilágosítást és segítséget. Elérhetiségek: hmo@lib.elte.hu, vagy a 3422-es mellék

  5. 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 solution. They are located in the large and small yellow rooms under the fume hoods with the other solvents be used. These are also found with other solvents in the small and large yellow rooms under the fume hoods

  6. AZ 300T / 400T Photoresist Stripper The CEPSR Clean Room stores AZ 300T and 400T photoresist strippers. They are located in

    E-print Network

    Kim, Philip

    AZ 300T / 400T Photoresist Stripper The CEPSR Clean Room stores AZ 300T and 400T photoresist strippers. They are located in both the large and small yellow rooms under the fume hood with the solvents. Both of these strippers contain alkaline ingredients that are able to clean wafer surfaces of organic

  7. Nature of the 1100 Micron AzTEC-COSMOS Sources

    NASA Astrophysics Data System (ADS)

    Yun, Min Su; Aguirre, J.; Aretxaga, I.; Austermann, J.; Bock, J.; Fazio, G.; Huang, J.; Hughes, D.; Kang, Y.; Kim, S.; Lowenthal, J.; Ma, C.; Mauskopf, P.; Perera, T.; Sanders, D.; Scott, K.; Scoville, N.; Wilson, G.; Yoon, I.

    2006-12-01

    The Cosmic Evolution Survey (COSMOS) is a 2 square degree HST/ACS survey specifically designed to probe galaxy evolution as a function of time and environment (PI: N. Scoville). To take advantage of the extensive complementary databases already available through the COSMOS collaboration, we have undertaken a 1100 micron imaging survey of a 30' x 30' field centered just north of the earlier mm/submm surveys by the Bolocam on CSO and MAMBO on the IRAM 30-m telescope. In this poster paper, we will compare the results of the AzTEC and Bolocam surveys and discuss the nature of the AzTEC sources based on the existing multi-wavelength data in hand.

  8. 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.

  9. Electroless nickel plating on AZ91 Mg alloy substrate

    Microsoft Academic Search

    Zhenmin Liu; Wei Gao

    2006-01-01

    Electroless Ni-plating on Mg alloy AZ91 has been studied to understand the effect of the substrate microstructure and roughness on the deposition rate, nucleation, coating microstructure, and mechanical property of the coatings. Experimental results indicate that the growth of Ni deposit in the early stage was influenced by the substrate microstructure and roughness. The electroless Ni-plating on the abrasive blasted

  10. Creep studies of AZ91D pressure die casting

    Microsoft Academic Search

    M. Regev; E. Aghion; A. Rosen

    1997-01-01

    Creep properties of pressure die cast AZ91D magnesium alloy (9% Al-1% Zn) were investigated in the temperature range of 150–180 °C and load range of 30–100 MPa. The pressure die cast material is characterized by a small grain size of about 10 ?m. Creep tests were performed under constant load and under varying load. Creep rates were found to be

  11. Crystallography of directionally solidified magnesium alloy AZ91

    Microsoft Academic Search

    Ketil Pettersen; Nils Ryum

    1989-01-01

    The crystallographic direction of growth in directionally solidified magnesium alloy AZ91 has been studied by TEM and EBSP\\u000a techniques in SEM. The main direction of growth is found to be\\u000a $$\\\\left\\\\langle {11\\\\bar 20} \\\\right\\\\rangle $$\\u000a . The dendrites have sixfold symmetry around the main direction, with secondary arms lying along the traces of the (0001),\\u000a $$\\\\left( {1\\\\bar 101} \\\\right)$$\\u000a ,

  12. Mexico City

    Atmospheric Science Data Center

    2013-04-18

    ... Mexico City has one of the world's most serious air pollution problems. The city is located atop a high plain at an altitude of ... as the orange and red areas, and mountainous areas appear light blue and green. The position of the clouds within the 70-degree image are ...

  13. 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 FORGEŽ 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].

  14. A study on stress corrosion cracking and hydrogen embrittlement of AZ31 magnesium alloy

    Microsoft Academic Search

    R. G. Song; C. Blawert; W. Dietzel; A. Atrens

    2005-01-01

    The stress corrosion cracking (SCC) behavior and pre-exposure embrittlement of AZ31 magnesium alloy have been studied by slow strain rate tensile (SSRT) tests in this paper. It is showed that AZ31 sheet material is susceptible to SCC in distilled water, ASTM D1387 solution, 0.01M NaCl and 0.1M NaCl solution. The AZ31 magnesium alloy also becomes embrittled if pre-exposed to 0.01M

  15. MWCNTs\\/AZ31 surface composites fabricated by friction stir processing

    Microsoft Academic Search

    Y. Morisada; H. Fujii; T. Nagaoka; M. Fukusumi

    2006-01-01

    Multi-walled carbon nanotubes (MWCNTs) were successfully dispersed into a magnesium alloy (AZ31) using friction stir processing (FSP). Distribution of the MWCNTs was changed on the basis of the travel speed of the FSP tool. The grain size of the MWCNTs\\/AZ31 surface composites was smaller than that of the FSPed AZ31 without the MWCNTs. The addition of the MWCNTs appears effective

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

    SciTech Connect

    RASMUSSEN, J.H.

    2000-05-23

    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.

  17. Histone Variant H2A.Z.2 Mediates Proliferation and Drug Sensitivity of Malignant Melanoma.

    PubMed

    Vardabasso, Chiara; Gaspar-Maia, Alexandre; Hasson, Dan; Pünzeler, Sebastian; Valle-Garcia, David; Straub, Tobias; Keilhauer, Eva C; Strub, Thomas; Dong, Joanna; Panda, Taniya; Chung, Chi-Yeh; Yao, Jonathan L; Singh, Rajendra; Segura, Miguel F; Fontanals-Cirera, Barbara; Verma, Amit; Mann, Matthias; Hernando, Eva; Hake, Sandra B; Bernstein, Emily

    2015-07-01

    Histone variants are emerging as key regulatory molecules in cancer. We report a unique role for the H2A.Z isoform H2A.Z.2 as a driver of malignant melanoma. H2A.Z.2 is highly expressed in metastatic melanoma, correlates with decreased patient survival, and is required for cellular proliferation. Our integrated genomic analyses reveal that H2A.Z.2 controls the transcriptional output of E2F target genes in melanoma cells. These genes are highly expressed and display a distinct signature of H2A.Z occupancy. We identify BRD2 as an H2A.Z-interacting protein, levels of which are also elevated in melanoma. We further demonstrate that H2A.Z.2-regulated genes are bound by BRD2 and E2F1 in an H2A.Z.2-dependent manner. Importantly, H2A.Z.2 deficiency sensitizes melanoma cells to chemotherapy and targeted therapies. Collectively, our findings implicate H2A.Z.2 as a mediator of cell proliferation and drug sensitivity in malignant melanoma, holding translational potential for novel therapeutic strategies. PMID:26051178

  18. 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.

  19. 75 FR 49526 - Freescale Semiconductor, Inc., Technical Information Center, Tempe, AZ; Freescale Semiconductor...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-13

    ...Freescale Semiconductor, Inc., Technical Information Center, Tempe, AZ; Freescale Semiconductor, Inc., Technical Information Center, Woburn, MA; Amended...Freescale Semiconductor, Inc., Technical Information Center, Tempe,...

  20. Virtual City

    NSDL National Science Digital Library

    1994-01-01

    In conjunction with Rice Design Alliance's Virtual City lecture series held earlier this year, home pages have been put up for two of the speakers, Howard Rheingold and Bruce Sterling, with access to online writings included.

  1. 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.

  2. 78 FR 32086 - Establishment of Class E Airspace; Tuba City, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-29

    ...aircraft under control of Denver...Route Traffic Control Centers (ARTCCs...management of IFR operations in the vicinity...Administration, Operations Support Group...Western Service Center, 1601 Lind...conditions under control of...

  3. 78 FR 17869 - Safety Zone; Desert Storm Shootout; Lake Havasu, Lake Havasu City, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-25

    ...safety zone on the navigable waters of the Colorado River in Lake Havasu, Lake...Marine safety, Navigation (water), Reporting and recordkeeping...safety zone encompasses the waters of Lake Havasu on the Colorado River and is bound by...

  4. 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.

  5. 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).

  6. COUNTRY INSTITUTION DATE WEB ADDRESS AZERBAIJAN Azerbaijan Medical University 15.03.2011 http://amu.edu.az/

    E-print Network

    Guidoni, Leonardo

    COUNTRY INSTITUTION DATE WEB ADDRESS AZERBAIJAN Azerbaijan Medical University 15.03.2011 http://amu.edu.az/ AZERBAIJAN Baku State University 23.09.2011 http://bsu.edu.az/en/ AZERBAIJAN University of Architecture

  7. 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

    ...Docket No. 10-AWP-5] Modification of Class D and E Airspace, and Revocation of Class E Airspace; Flagstaff, AZ AGENCY: Federal Aviation...SUMMARY: This action will modify Class D and E airspace at Flagstaff, AZ, to accommodate...

  8. 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 E Airspace; Flagstaff, AZ AGENCY: Federal Aviation...SUMMARY: This action proposes to modify Class D and E airspace at Flagstaff, AZ, to accommodate...

  9. Stress corrosion cracking behavior of Nd:YAG laser butt welded AZ31 Mg sheet

    Microsoft Academic Search

    M. Bobby Kannan; W. Dietzel; C. Blawert; S. Riekehr; M. Koçak

    2007-01-01

    In this study, the stress corrosion cracking (SCC) behavior of samples fabricated from AZ31 Mg alloy by laser butt welding was investigated in slow strain rate tensile (SSRT) and constant load tests. The results show that the laser butt welded AZ31 Mg samples are highly susceptible to SCC. The failure of the samples occurred in the fusion boundary when tested

  10. Using SAS for analyzing Website traffic Chong Ho Yu, Tempe, AZ

    E-print Network

    Yu, Alex

    Not everything in the user log is useful. Typically what can be used are the IP address (From where did the users Samuel DiGangi, Tempe, AZ James Carvalho, Tempe, AZ Abstract Tracking Web traffic is crucial to both dummy 0-dummy7 datetime); infile indata firstobs=3 missover; length ip $ 15 datetime $ 21 hit $ 40 temp2

  11. 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 ...

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

    E-print Network

    Zhou, Wei

    of porosity in the welds. The welding was conducted using alternating current at a voltage of 20­22 V,2 Magnesium alloy AZ91D is widely used because of its relatively higher corrosion resistance and mechanical,4 corrosion resistance5­8 and mechanical properties9 of AZ91D magnesium alloys. Effort has also been made

  13. Tank 241-AZ-102 SuperLig 639 Technetium Ion Exchange Eluate Evaporation Study

    Microsoft Academic Search

    2001-01-01

    As part of the Hanford River Protection Project (RPP), the Savannah River Technology Center (SRTC) has conducted tests on the pretreatment and vitrification of a radioactive waste sample from Hanford Tank 241-AZ-102. The original, AZ-102 sample which was received at SRTC was characterized and filtered to remove entrained solids.1 The sample was then passed sequentially through ion exchange columns containing

  14. Incremental forming of free surface with magnesium alloy AZ31 sheet at warm temperatures

    Microsoft Academic Search

    Y. H. JI; J. J. PARK

    2008-01-01

    The formability of AZ31 sheet begins to increase drastically at 150 °C. The incremental forming technique was thus applied to AZ31 sheet at 150 °C to utilize the formability to its fullest capacity at the lowest possible temperature for forming applications. A surface scanning technique was used followed by the tool path generation to incrementally form an egg surface. After

  15. Numerical simulation on warm deep drawing of magnesium alloy AZ31 sheets

    Microsoft Academic Search

    L. M. Ren; S. H. Zhang; G. Palumbo; D. Sorgente; L. Tricarico

    2009-01-01

    Warm forming of magnesium alloys has attracted much attention due to the very poor formability of Mg alloys at room temperature. In the present paper, the warm deep drawing of magnesium alloy AZ31 (3wt.% Al, 1wt.% Zn) sheets was studied by both the experimental approach and the finite element analysis. The results indicated that the formability of the AZ31 sheets

  16. COUNTRY INSTITUTION DATE WEB ADDRESS AZERBAIJAN Azerbaijan Medical University 15.03.2011 http://amu.edu.az/

    E-print Network

    Guidoni, Leonardo

    COUNTRY INSTITUTION DATE WEB ADDRESS AZERBAIJAN Azerbaijan Medical University 15.03.2011 http://amu.edu.az/ AZERBAIJAN Baku State University 23.09.2011 http://bsu.edu.az/en/ AZERBAIJAN University of Architecture and Construction 16.12.2011 http://www.azmiu.edu.az AZERBAIJAN Azerbaijan Technical University 24.06.2013 http

  17. The Cities.

    ERIC Educational Resources Information Center

    Nathan, Richard P.; Dommel, Paul R.

    Over the past two decades, direct payments from the Federal Government to local governments has increased more than sixfold as a percentage of the revenues local governments raise on their own. Both the Ford budget and the Carter budget revisions for 1977 and 1978 contain policy changes with important implications for cities. In this document…

  18. 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.

  19. Fabrication and characterization of AZ91/CNT magnesium matrix composites

    NASA Astrophysics Data System (ADS)

    Park, Yong-Ha; Park, Yong-Ho; Park, Ik-Min; Oak, Jeong-jung; Kimura, Hisamichi; Cho, Kyung-Mox

    2008-12-01

    Carbon Nano Tube (CNT) reinforced AZ91 metal matrix composites (MMC) were fabricated by the squeeze infiltrated method. Properties of magnesium alloys have been improved by impurity reduction, surface treatment and alloy design, and thus the usage for the magnesium alloys has been extended recently. However there still remain barriers for the adaption of magnesium alloys for engineering materials. In this study, we report light-weight, high strength heat resistant magnesium matrix composites. Microstructural study and tensile test were performed for the squeeze infiltrated magnesium matrix composites. The wear properties were characterized and the possibility for the application to automotive power train and engine parts was investigated. It was found that the squeeze infiltration technique is a proper method to fabricate magnesium matrix composites reducing casting defects such as pores and matrix/reinforcement interface separation etc. Improved tensile and mechanical properties were obtained with CNT reinforcing magnesium alloys

  20. Curious City

    NSDL National Science Digital Library

    Chicago, what are you curious about? That might serve as the tagline for the WBEZ radio program "Curious City," as it's an inquisitive program that asks its listeners that exact question. The public submits queries about Chicago here on the show's site, visitors vote for the questions they like the best, and then the crack team at Curious City investigates and reports back, complete with help from locals who want to be part of the whole recursive process. On the site, visitors can look over the Up For Voting area, which includes questions that cover everything from Cook County Hospital to the design of Wrigley Field. For complete audio and written answers to questions that are wrapped up, click on over to the Answered & Investigating area. Here visitors can look over questions such as "Will the Pullman neighborhood ever be revitalized?" and "What is the origin of Chicago's distinctive wooden fire escapes?"

  1. 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.

  2. Project W-211 Initial Tank Retrieval Systems (ITRS) Description of Operations for 241-AZ-102

    SciTech Connect

    BRIGGS, S.R.

    2000-02-25

    The primary purpose of the Initial Tank Retrieval Systems (ITRS) is to provide systems for retrieval of radioactive wastes stored in underground double-shell tanks (DSTs) for transfer to alternate storage, evaporation, pretreatment or treatment, while concurrently reducing risks associated with safety watch list and other DSTs. This Description of Operation (DOO) defines the control philosophy for the waste retrieval system for Tank 241-AZ-102 (AZ-102). This DOO provides a basis for the detailed design of the Project W-211 Retrieval Control System (RCS) for AZ-102 and also establishes test criteria for the RCS.

  3. 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.

  4. Microstructure of high pressure die cast AZ91D modified with Ca and Ce

    Microsoft Academic Search

    L. Shepeleva; M. Bamberger

    2006-01-01

    High pressure die cast (HPDC) AZ91D (Mg–8.8wt%Al–0.74wt%Zn–0.29wt%Mn) modified with Ca and Ce was investigated. Thermodynamic calculations of liquid\\/solid equilibrium were confirmed by DTA measurements and solid\\/liquid equilibrium at various temperatures between the liquidus and solidus temperatures.The solidification path of HPDC AZ91 and AZ91 modified with Ca and Ce was calculated using the Termo-Calc program. The microstructure was investigated utilizing optical

  5. 76 FR 78180 - Proposed Modification of Class E Airspace; Douglas, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-16

    ...AZ. Decommissioning of the Cochise Very High Frequency Omni-Directional Radio Range Tactical Air Navigational Aid (VORTAC) has...accommodate aircraft using VHF Omni-Directional Radio Range/Distance Measuring Equipment VOR/DME...

  6. 75 FR 28778 - Magma Flood Retarding Structure (FRS) Supplemental Watershed Plan, Pinal County, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-24

    ...Retarding Structure (FRS) Supplemental Watershed Plan, Pinal County, AZ AGENCY: Natural...Retarding Structure (FRS) Supplemental Watershed Plan, Pinal County, Arizona. FOR FURTHER...Domestic Assistance under No. 10.904, Watershed Protection and Flood Prevention,...

  7. 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 ...

  8. The Histone Chaperones FACT and Spt6 Restrict H2A.Z from Intragenic Locations.

    PubMed

    Jeronimo, Célia; Watanabe, Shinya; Kaplan, Craig D; Peterson, Craig L; Robert, François

    2015-06-18

    H2A.Z is a highly conserved histone variant involved in several key nuclear processes. It is incorporated into promoters by SWR-C-related chromatin remodeling complexes, but whether it is also actively excluded from non-promoter regions is not clear. Here we provide genomic and biochemical evidence that the RNA polymerase II (RNA Pol II) elongation-associated histone chaperones FACT and Spt6 both contribute to restricting H2A.Z from intragenic regions. In the absence of FACT or Spt6, the lack of efficient nucleosome reassembly coupled to pervasive incorporation of H2A.Z by mislocalized SWR-C alters chromatin composition and contributes to cryptic initiation. Therefore, chaperone-mediated H2A.Z confinement is crucial for restricting the chromatin signature of gene promoters that otherwise may license or promote cryptic transcription. PMID:25959393

  9. Effect of Carbon Nanotube on High-Temperature Formability of AZ31 Magnesium Alloy

    NASA Astrophysics Data System (ADS)

    Hassan, S. Fida; Paramsothy, M.; Gasem, Z. M.; Patel, F.; Gupta, M.

    2014-08-01

    Room-temperature tensile properties of AZ31 alloy have significantly been improved when reinforced with carbon nanotube via ingot metallurgy process. However, high-temperature (up to 250 °C) elongation-to-failure tensile test of the developed nanocomposite revealed a considerable softening in the AZ31 alloy matrix accompanied by an incredible ductility increment (up to 132%). Microstructural characterization of the fractured samples revealed that the dynamic recrystallization process has induced a complete recrystallization in the AZ31 alloy at a lower temperature (150 °C) followed by substantial grain growth at a higher temperature used in this study. Fractography on the fractured surfaces revealed that the room-temperature mixed brittle-ductile modes of fracture behavior of AZ31 alloy have transformed into a complete ductile mode of fracture at high temperature.

  10. 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 of Engineering and Technology, IUPUI When considering implantable biomaterials, one possible solution that has taken to find appropriate coatings. One possibility is microarc oxidation (MAO) coating. However

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

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-12

    ...LABOR Employment and Training Administration [TA-W-70,654] DNS Electronics, Chandler, AZ; Notice of Termination of Investigation...workers is covered by an active certification (TA-W-72,553), which expires on December 17,...

  12. Patterning chromatin: form and function for H2A.Z variant nucleosomes.

    PubMed

    Raisner, Ryan M; Madhani, Hiten D

    2006-04-01

    Although many histone variants are specific to higher eukaryotes, the H2A variant H2A.Z has been conserved during eukaryotic evolution. Genetic studies have demonstrated roles for H2A.Z in antagonizing gene-silencing, chromosome stability and gene activation. Biochemical work has identified a conserved chromatin-remodeling complex responsible for H2A.Z deposition. Recent studies have shown that two H2A.Z nucleosomes flank a nucleosome-free region containing the transcription initiation site in promoters of both active and inactive genes in Saccharomyces cerevisiae. This chromatin pattern is generated through the action of a DNA deposition signal and a specific pattern of histone tail acetylation. PMID:16503125

  13. Operational test procedure 241-AZ-101 waste tank color video camera system

    SciTech Connect

    Robinson, R.S.

    1996-10-30

    The purpose of this procedure is to provide a documented means of verifying that all of the functional components of the 241-AZ- 101 Waste Tank Video Camera System operate properly before and after installation.

  14. State Laboratory Contact Information A-Z Mailing Address Shipping Address Contact

    E-print Network

    State Director's List No Certificate Florida Mailing Address Contact Information Florida DepartmentState Laboratory Contact Information A-Z Alabama Mailing Address Shipping Address Contact Information Alabama Department of Agriculture & Industries Weights and Measures Laboratory PO Box 3336

  15. 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.

  16. 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...

  17. 77 FR 25741 - Notice of Inventory Completion: Arizona State Museum, University of Arizona, Tucson, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-01

    ...of Inventory Completion: Arizona State Museum, University of Arizona, Tucson, AZ...SUMMARY: The Arizona State Museum, University of Arizona, has completed...objects may contact the Arizona State Museum, University of Arizona....

  18. Microstructure and corrosion resistance of Ce-V conversion coating on AZ31 magnesium alloy

    NASA Astrophysics Data System (ADS)

    Jiang, Xiao; Guo, Ruiguang; Jiang, Shuqin

    2015-06-01

    A Ce-V conversion coating was developed to improve the corrosion resistance of AZ31 magnesium alloy. Scanning electronic microscope (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectrometer (XPS), grazing incidence X-ray diffraction (GIXRD) and the ball cratering test were adopted to study the morphology, chemical composition, structure and thickness of the coating. The coating has duplex structure with network and its thickness is about 2 ?m. The coating contains high contents of Ce and V, which exhibits amorphous structure. Potentiodynamic polarization shows the coating can increase the corrosion potential and reduce the corrosion current density of AZ31 magnesium alloy. Moreover, the electrochemical impedance spectra exhibit the coating significantly improves the corrosion resistance of AZ31 magnesium alloy. Results indicate that the Ce-V conversion coating can provide effective protection to AZ31 magnesium alloy.

  19. Thermal stress analysis of fused-cast AZS refractories during production; Part 1: Industrial study

    Microsoft Academic Search

    Steven L. Cockcroft; J. Keith Brimacombe; Dennis G. Walrod; Thomas A. Myles

    1994-01-01

    A study has been conducted to understand and prevent the formation of cracks in alumina-zirconia-silica (AZS) refractory blocks during solidification processing. A fundamental approach has been taken, centered on the development of a three-dimensional mathematical model to predict heat flow and stress generation in fused-cast AZS refractory blocks. In the first part of a two-part study, the voidless'' casting process

  20. Egy Gogol-szöveghely Puskin-hivatkozásáról (A démon cím? költemény szerepe Az arcképben)

    E-print Network

    Kroó , Katalin

    2009-01-01

    továbbiakban: Portré) cí- m? elbeszélésének a poétikai anyagába beleszövi Puskin nevét, méghozzá úgy, hogy ezzel az olvasatot nyomatékosan egy konkrét Puskin-m?höz, A démon cím? költeményhez (1823) vezeti. Nem is akárhogyan. Gogol nem egyszer?en egy költ?i... ideálisan ábrázolta. Az elbeszél?i szövegrészlet úgy jeleníti meg a puskini démon-ábrázoláshoz kötött kett?s szemantikai perspektívát (annak mintegy megfejtett értelmét feltárva), hogy e kett?sséget, magának Puskinnak tulajdo- nítja (megközelít?leg ilyen...

  1. Sliding Wear Characteristics of AZ91D Alloy at Ambient Temperatures of 25–200 °C

    Microsoft Academic Search

    S. Q. WangZ; Z. R. Yang; Y. T. Zhao; M. X. Wei

    2010-01-01

    The dry sliding wear tests were performed for AZ91D alloy under the loads of 12.5–300 N and the ambient temperatures of 25–200 °C.\\u000a We studied the wear characteristics of AZ91D alloy as a function of the normal load and the ambient temperature. The mild-to-severe\\u000a wear transition occurred with increasing the load and the critical load reduced with the ambient temperature rising. However,

  2. Studies on thermal oxidation of Mg-alloy (AZ91) for improving corrosion and wear resistance

    Microsoft Academic Search

    J. Dutta Majumdar; U. Bhattacharyya; A. Biswas; I. Manna

    2008-01-01

    The present investigation concerns development of an adherent stable oxide layer on the surface of a Mg alloy, AZ91 (8.3–9.7% Al, 0.13% Mn, 1.0% Zn, 0.50% Si, 0.10% Cu, 0.03% Ni, 0.30% other, balance Mg) by thermal oxidation to improve wear and corrosion resistance in simulated body fluid. Oxide layer was developed by thermal oxidation of freshly polished AZ91 samples

  3. Electrodeposition of high corrosion resistance Cu\\/Ni–P coating on AZ91D magnesium alloy

    Microsoft Academic Search

    Shan Zhang; Fahe Cao; Linrong Chang; Junjun Zheng; Zhao Zhang; Jianqing Zhang; Chunan Cao

    2011-01-01

    High corrosion resistance Cu\\/Ni–P coatings were electrodeposited on AZ91D magnesium alloy via suitable pretreatments, such as one-step acid pickling-activation, once zinc immersion and environment-friendly electroplated copper as the protective under-layer, which made Ni–P deposit on AZ91D Mg alloy in acid plating baths successfully. The pH value and current density for Ni–P electrodeposition were optimized to obtain high corrosion resistance. With

  4. Influence of silane on corrosion resistance of magnesium alloy AZ31 with thermally sprayed aluminum coatings

    Microsoft Academic Search

    Rongchang Zeng; Jun Chen; Jun Kuang; Jin Zhang; Ying Wang

    2010-01-01

    Aluminum coatings on Mg alloy AZ31 were fabricated using the thermal spraying technique, and then sealed with silane. The\\u000a surface morphology and chemical groups were discerned using scanning electron microscopy and examined using Fourier transformation\\u000a infrared spectroscopy, respectively. The salt fog tests and the potentiodynamic electrochemical technique were applied to\\u000a evaluate the influence of silane on corrosion of the AZ31

  5. Project W-314 specific test and evaluation plan for AZ tank farm upgrades

    Microsoft Academic Search

    Hays

    1998-01-01

    The purpose of this Specific Test and Evaluation Plan (STEP) is to provide a detailed written plan for the systematic testing of modifications made by the addition of the SN-631 transfer line from the AZ-O1A pit to the AZ-02A pit by the W-314 Project. The STEP develops the outline for test procedures that verify the system`s performance to the established

  6. Interaction of polyamines and mTOR signaling in the synthesis of antizyme (AZ).

    PubMed

    Ray, Ramesh M; Bavaria, Mitul; Johnson, Leonard R

    2015-09-01

    Tissue polyamine levels are largely determined by the activity of ornithine decarboxylase (ODC, EC 4.1.17), which catalyzes the conversion of ornithine to the diamine putrescine. The activity of the enzyme is primarily regulated by a negative feedback mechanism involving ODC antizyme (AZ). Our previous studies demonstrated that AZ synthesis is stimulated by the absence of amino acids, the levels of which are sensed by the mTOR complex containing TORC1, which is stimulated by amino acids and inhibited by their absence, and TORC2 the function of which is not well defined. Polyamines, which cause a +1 ribosomal frameshift during the translation of AZ mRNA are required to increase AZ synthesis in both the presence and absence of amino acids. Amino acid starvation increases TORC2 activity. We have demonstrated that mTORC2 activity is necessary for AZ synthesis in the absence of amino acids. Tuberous sclerosis protein (TSC), a negative regulator of mTOR function regulates the activities of both the TORC1 and TORC2. TSC2 knockdown increased mTORC1 activity with concomitant inhibition of mTORC2 activity eliminating AZ induction in the absence of amino acids as well as that induced by spermidine. Thus, these results clearly demonstrate that in addition to polyamines, mTORC2 activity is necessary for AZ synthesis. Moreover, our results support a role for mTORC2 in the synthesis of a specific protein, AZ, which regulates growth of intestinal epithelial cells. PMID:26093026

  7. Final results of double-shell tank 241-AZ-101 ultrasonic inspection

    SciTech Connect

    JENSEN, C.E.

    1999-08-23

    This document presents the results and documentation of the nondestructive ultrasonic examination of tank 241-AZ-101. A tank inspection supplier was retained to provide and use an ultrasonic examination system (equipment, procedures, and inspectors) to scan a limited area of double-shell tank 241-AZ-101 primary tank wall and welds. The inspection found one reportable indication of thinning and no reportable pitting, corrosion, or cracking.

  8. Box City Curriculum.

    ERIC Educational Resources Information Center

    Center for Understanding the Built Environment, Prairie Village, KS.

    This curriculum packet contains two lesson plans about cities and architecture intended for use with students in upper elementary grades and middle schools. The first lesson plan, "City People, City Stories" (Jan Ham), states that understanding architecture and cities must begin with an understanding of the people of the city. The children create…

  9. Oxide Film and Porosity Defects in Magnesium Alloy AZ91

    SciTech Connect

    Wang, Liang [Mississippi State University (MSU); Rhee, Hongjoo [Mississippi State University (MSU); Felicelli, Sergio D. [Mississippi State University (MSU); Sabau, Adrian S [ORNL; Berry, John T. [Mississippi State University (MSU)

    2009-01-01

    Porosity is a major concern in the production of light metal parts. This work aims to identify some of the mechanisms of microporosity formation in magnesium alloy AZ91. Microstructure analysis was performed on several samples obtained from gravity-poured ingots in graphite plate molds. Temperature data during cooling was acquired with type K thermocouples at 60 Hz at three locations of each casting. The microstructure of samples extracted from the regions of measured temperature was then characterized with optical metallography. Tensile tests and conventional four point bend tests were also conducted on specimens cut from the cast plates. Scanning electron microscopy was then used to observe the microstructure on the fracture surface of the specimens. The results of this study revealed the existence of abundant oxide film defects, similar to those observed in aluminum alloys. Remnants of oxide films were detected on some pore surfaces, and folded oxides were observed in fracture surfaces indicating the presence of double oxides entrained during pouring.

  10. Microstructures and wear property of friction stir welded AZ91 Mg\\/SiC particle reinforced composite

    Microsoft Academic Search

    Won-Bae Lee; Chang-Yong Lee; Myoung-Kyun Kim; Jung-Il Yoon; Young-Jig Kim; Yun-Mo Yoen; Seung-Boo Jung

    2006-01-01

    The microstructures and wear property of friction stir welded AZ91 Mg alloy\\/SiC particle reinforced composite (AZ91\\/SiC\\/10p) were investigated. The initial microstructures of the AZ91\\/SiC\\/10p were composed of irregularly distributed ?-phases (Al12Mg17) and agglomerated SiC particles, while the friction stir weld zone was characterized by the homogeneous distribution of SiC particles, the recrystallized grain structure and the dissolution of ?-phase. Thank

  11. 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

    osztálya. Fiszerkeszti: Kálóczi Katalin fiigazgató-helyettes. Szerkeszti: Fábián Edit (fabian.edit@lib.elte.hu részt kívánnak venni a tanfolyamon, ezt jelezzék Tóth Norbert kollégánknak az alábbi e-mail címen: toth.norbert@lib.elte.hu-helyettes. Szerkeszti: Fábián Edit (fabian.edit@lib.elte.hu) 2 szabályzat tartalmazza. A módosításokról, a javítások

  12. Az ELTE knyvtrosainak hrlevele. Kiadja az ELTE Egyetemi Knyvtr Hlzati s mdszertani osztlya. Fszerkeszt: Klczi Katalin figazgat-helyettes. Szerkeszt: Zsmboki Mnika (zsamboki.monika@lib.elte.hu)

    E-print Network

    Müller, Viktor

    osztálya. Fszerkeszt: Kálóczi Katalin figazgató-helyettes. Szerkeszt: Zsámboki Mónika (zsamboki.monika@lib.elte.hu figazgató-helyettes. Szerkeszt: Zsámboki Mónika (zsamboki.monika@lib.elte.hu) 2 o teljesítménymutatók linken érhetk el: http://konyvtar.elte.hu/k21/esemenyek/index.html#101208 Az ELTE BTK könyvtárainak

  13. Az ELTE knyvtrosainak hrlevele. Kiadja az ELTE Egyetemi Knyvtr Hlzati s mdszertani osztlya. Fszerkeszt: Klczi Katalin figazgat-helyettes. Szerkeszt: Zsmboki Mnika (zsamboki.monika@lib.elte.hu)

    E-print Network

    Müller, Viktor

    osztálya. Fszerkeszt: Kálóczi Katalin figazgató-helyettes. Szerkeszt: Zsámboki Mónika (zsamboki.monika@lib.elte.hu helyeket is. További információk az országos rendezvény honlapján: http://www.oroksegnapok.hu módszertani osztálya. Fszerkeszt: Kálóczi Katalin figazgató-helyettes. Szerkeszt: Zsámboki Mónika (zsamboki.monika@lib.elte.hu

  14. 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.

  15. 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.

  16. Devolatilization or melting of carbonates at Meteor Crater, AZ?

    NASA Astrophysics Data System (ADS)

    Hörz, F.; Archer, P. D.; Niles, P. B.; Zolensky, M. E.; Evans, M.

    2015-06-01

    We have investigated the carbonates in the impact melts and in a monolithic clast of highly shocked Coconino sandstone of Meteor Crater, AZ to evaluate whether melting or devolatilization is the dominant response of carbonates during high-speed meteorite impact. Both melt- and clast-carbonates are calcites that have identical crystal habits and that contain anomalously high SiO2 and Al2O3. Also, both calcite occurrences lack any meteoritic contamination, such as Fe or Ni, which is otherwise abundantly observed in all other impact melts and their crystallization products at Meteor Crater. The carbon and oxygen isotope systematics for both calcite deposits suggest a low temperature environment (<100 °C) for their precipitation from an aqueous solution, consistent with caliche. We furthermore subjected bulk melt beads to thermogravimetric analysis and monitored the evolving volatiles with a quadrupole mass spectrometer. CO2 yields were <5 wt%, with typical values in the 2 wt% range; also total CO2 loss is positively correlated with H2O loss, an indication that most of these volatiles derive from the secondary calcite. Also, transparent glasses, considered the most pristine impact melts, yield 100 wt% element totals by EMPA, suggesting complete loss of CO2. The target dolomite decomposed into MgO, CaO, and CO2; the CO2 escaped and the CaO and MgO combined with SiO2 from coexisting quartz and FeO from the impactor to produce the dominant impact melt at Meteor Crater. Although confined to Meteor Crater, these findings are in stark contrast to Osinski et al. (2008) who proposed that melting of carbonates, rather than devolatilization, is the dominant process during hypervelocity impact into carbonate-bearing targets, including Meteor Crater.

  17. Devolatilization or melting of carbonates at Meteor Crater, AZ?

    NASA Astrophysics Data System (ADS)

    HöRz, F.; Archer, P. D.; Niles, P. B.; Zolensky, M. E.; Evans, M.

    2015-05-01

    We have investigated the carbonates in the impact melts and in a monolithic clast of highly shocked Coconino sandstone of Meteor Crater, AZ to evaluate whether melting or devolatilization is the dominant response of carbonates during high-speed meteorite impact. Both melt- and clast-carbonates are calcites that have identical crystal habits and that contain anomalously high SiO2 and Al2O3. Also, both calcite occurrences lack any meteoritic contamination, such as Fe or Ni, which is otherwise abundantly observed in all other impact melts and their crystallization products at Meteor Crater. The carbon and oxygen isotope systematics for both calcite deposits suggest a low temperature environment (<100 °C) for their precipitation from an aqueous solution, consistent with caliche. We furthermore subjected bulk melt beads to thermogravimetric analysis and monitored the evolving volatiles with a quadrupole mass spectrometer. CO2 yields were <5 wt%, with typical values in the 2 wt% range; also total CO2 loss is positively correlated with H2O loss, an indication that most of these volatiles derive from the secondary calcite. Also, transparent glasses, considered the most pristine impact melts, yield 100 wt% element totals by EMPA, suggesting complete loss of CO2. The target dolomite decomposed into MgO, CaO, and CO2; the CO2 escaped and the CaO and MgO combined with SiO2 from coexisting quartz and FeO from the impactor to produce the dominant impact melt at Meteor Crater. Although confined to Meteor Crater, these findings are in stark contrast to Osinski et al. (2008) who proposed that melting of carbonates, rather than devolatilization, is the dominant process during hypervelocity impact into carbonate-bearing targets, including Meteor Crater.

  18. Histone H2A.Z subunit exchange controls consolidation of recent and remote memory.

    PubMed

    Zovkic, Iva B; Paulukaitis, Brynna S; Day, Jeremy J; Etikala, Deepa M; Sweatt, J David

    2014-11-27

    Memory formation is a multi-stage process that initially requires cellular consolidation in the hippocampus, after which memories are downloaded to the cortex for maintenance, in a process termed systems consolidation. Epigenetic mechanisms regulate both types of consolidation, but histone variant exchange, in which canonical histones are replaced with their variant counterparts, is an entire branch of epigenetics that has received limited attention in the brain and has never, to our knowledge, been studied in relation to cognitive function. Here we show that histone H2A.Z, a variant of histone H2A, is actively exchanged in response to fear conditioning in the hippocampus and the cortex, where it mediates gene expression and restrains the formation of recent and remote memory. Our data provide evidence for H2A.Z involvement in cognitive function and specifically implicate H2A.Z as a negative regulator of hippocampal consolidation and systems consolidation, probably through downstream effects on gene expression. Moreover, alterations in H2A.Z binding at later stages of systems consolidation suggest that this histone has the capacity to mediate stable molecular modifications required for memory retention. Overall, our data introduce histone variant exchange as a novel mechanism contributing to the molecular basis of cognitive function and implicate H2A.Z as a potential therapeutic target for memory disorders. PMID:25219850

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

    SciTech Connect

    TEMPLETON, A.M.

    1999-07-08

    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. 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.

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

    SciTech Connect

    TEMPLETON, A.M.

    2000-03-06

    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.

  1. 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.

  2. Blocking spinal CCR2 with AZ889 reversed hyperalgesia in a model of neuropathic pain

    PubMed Central

    2010-01-01

    Background The CCR2/CCL2 system has been identified as a regulator in the pathogenesis of neuropathy-induced pain. However, CCR2 target validation in analgesia and the mechanism underlying antinociception produced by CCR2 antagonists remains poorly understood. In this study, in vitro and in vivo pharmacological approaches using a novel CCR2 antagonist, AZ889, strengthened the hypothesis of a CCR2 contribution to neuropathic pain and provided confidence over the possibilities to treat neuropathic pain with CCR2 antagonists. Results We provided evidence that dorsal root ganglia (DRG) cells harvested from CCI animals responded to stimulation by CCL2 with a concentration-dependent calcium rise involving PLC-dependent internal stores. This response was associated with an increase in evoked neuronal action potentials suggesting these cells were sensitive to CCR2 signalling. Importantly, treatment with AZ889 abolished CCL2-evoked excitation confirming that this activity is CCR2-mediated. Neuronal and non-neuronal cells in the spinal cord were also excited by CCL2 applications indicating an important role of spinal CCR2 in neuropathic pain. We next showed that in vivo spinal intrathecal injection of AZ889 produced dose-dependent analgesia in CCI rats. Additionally, application of AZ889 to the exposed spinal cord inhibited evoked neuronal activity and confirmed that CCR2-mediated analgesia involved predominantly the spinal cord. Furthermore, AZ889 abolished NMDA-dependent wind-up of spinal withdrawal reflex pathway in neuropathic animals giving insight into the spinal mechanism underlying the analgesic properties of AZ889. Conclusions Overall, this study strengthens the important role of CCR2 in neuropathic pain and highlights feasibility that interfering on this mechanism at the spinal level with a selective antagonist can provide new analgesia opportunities. PMID:21143971

  3. Autophagy limits the cytotoxic effects of the AKT inhibitor AZ7328 in human bladder cancer cells

    PubMed Central

    Dickstein, Rian J.; Nitti, Giovanni; Dinney, Colin P.; Davies, Barry R.; Kamat, Ashish M.; McConkey, David J.

    2012-01-01

    Background: Mutations that activate the PI3K/AKT/mTOR pathway are relatively common in urothelial (bladder) cancers, but how these pathway mutations affect AKT dependency is not known. We characterized the relationship between AKT pathway mutational status and sensitivity to the effects of the selective AKT kinase inhibitor AZ7328 using a panel of 12 well-characterized human bladder cancer cell lines. Methods: Sequenome DNA sequencing was performed to identify mutations in a panel of 12 urothelial cancer cell lines. Drug-induced proliferative inhibition and apoptosis were quantified using MTT assays and propidium iodide staining with FACS analyses. Protein activation via phosphorylation was measured by immunoblotting. Autophagy was measured by LC3 immunofluorescence and immunoblotting. Results: AZ7328 inhibited proliferation and AKT substrate phosphorylation in a concentration-dependent manner but had minimal effects on apoptosis. Proliferative inhibition correlated loosely with the presence of activating PIK3CA mutations and was strengthened in combination with the mTOR inhibitor rapamycin. AZ7328 induced autophagy in some of the lines, and in the cells exposed to a combination of AZ7328 and chemical autophagy inhibitors apoptosis was induced. Conclusions: The cytostatic effects of AZ7328 correlate with PIK3CA mutations and are greatly enhanced by dual pathway inhibition using an mTOR inhibitor. Furthermore, AZ7328 can interact with autophagy inhibitors to induce apoptosis in some cell lines. Overall, our results support the further evaluation of combinations of PI3K/AKT/mTOR pathway and autophagy inhibitors in pre-clinical in vivo models and ultimately in patients with PIK3CA mutant bladder cancers. PMID:22895070

  4. Draft Genome Sequence of the Sulfolobales Archaeon AZ1, Obtained through Metagenomic Analysis of a Mexican Hot Spring

    PubMed Central

    Martínez-Romero, Esperanza

    2014-01-01

    The Sulfolobales archaea have been found inhabiting acidic hot springs all over the world. Here, we report the 1.798-Mbp draft genome sequence of the thermoacidophilic Sulfolobales archaeon AZ1, reconstructed from the metagenome of a Mexican hot spring. Sequence-based comparisons revealed that the Sulfolobales archaeon AZ1 represents a novel candidate genus. PMID:24604657

  5. Effect of micro-texture on fracture location in friction stir weld of Mg alloy AZ61 during tensile test

    Microsoft Academic Search

    Seung Hwan C. Park; Yutaka S. Sato; Hiroyuki Kokawa

    2003-01-01

    Microstructural evolution of magnesium alloy AZ61 during friction stir welding and details of the relationship between the microstructure and mechanical properties are discussed. Tensile properties of the weld of Mg alloy AZ61 were strongly influenced by crystallographic orientation distribution as well as by grain size and dislocation density.

  6. Histone Variant H2A.Z Regulates Centromere Silencing and Chromosome Segregation in Fission Yeast*S

    E-print Network

    Jia, Songtao

    Histone Variant H2A.Z Regulates Centromere Silencing and Chromosome Segregation in Fission Yeast, or H2A.Z results in loss of silencing at centromeres and defective chromosome segregation, although centromeric levels of CENP-A, a centromere-specific histone H3 variant that is required for setting up

  7. CSER 96-014: criticality safety of project W-151, 241-AZ-101 retrieval system process test

    Microsoft Academic Search

    Vail; Fluor Daniel Hanford

    1997-01-01

    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

  8. Anticorrosive magnesium hydroxide coating on AZ31 magnesium alloy by hydrothermal method

    NASA Astrophysics Data System (ADS)

    Zhu, Yanying; Wu, Guangming; Zhao, Qing; Zhang, Yun-Hong; Xing, Guangjian; Li, Donglin

    2009-09-01

    Magnesium alloys are potential biodegradable biomaterials in orthopedic surgery. However, the rapid degradation rate has limited their application in biomedical field. A great deal of studies have been done to improve the resistance of magnesium alloys. In this article, An anticorrosive magnesium hydroxide coating with a thickness of approximately 100?m was formed on an AZ31 magnesium alloy by hydrothermal method. The morphology of the coatings were observed by an optical microscope and SEM. And the samples were soaked in hank's solution (37°C) to investigate the corrosion resistance. Magnesium alloy AZ31 with magnesium hydroxide coatings present superior corrosion resistance than untreated samples.

  9. Effects of the types of overlap on the mechanical properties of FSSW welded AZ series magnesium alloy joints

    NASA Astrophysics Data System (ADS)

    Wang, Dan; Shen, Jun; Wang, Lin-Zhi

    2012-03-01

    The effects of the types of overlap on the mechanical properties of the friction stir spot welding (FSSW) welded AZ series magnesium alloy joints were investigated by microstructural observations, microhardness tests, and tensile tests. The results show that the microstructure of the stir zone adjacent to the periphery of the rotating pin is mainly composed of the upper sheet. The average distance D between the longitudinal segment of the curved interface and the keyhole periphery, the tensile shear force, and the microhardness of the stir zone of the FSSW welded AZ61 alloy joint are the highest in all samples. During FSSW of AZ31 and AZ61 dissimilar magnesium alloys, the irregular deformation of the longitudinal segment of the curved interface appears, while the microhardness of the stir zone is higher when AZ61 alloy is the upper sheet. Moreover, the microhardness of the stir zone increases initially and then decreases sharply in the longitudinal test position.

  10. 2 CITY COUNCIL CITY OF NEW YORK

    E-print Network

    Columbia University

    1 2 CITY COUNCIL 3 CITY OF NEW YORK 4 -------------------------------x 5 THE TRANSCRIPT 8, 2002 Start: 10:27 a.m. 11 Recess: 2:56 p.m. 12 City Hall Council Chambers 13 New York, New York 25 New York, New York 10004 (800) 756-3410 #12;2 1 2 A P P E A R A N C E S 3 Christopher O. Ward 4

  11. 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.

  12. 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…

  13. 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

  14. WM'02 Conference, February 24-28, 2002, Tucson, AZ ENVIRONMENTAL RADIATION PROTECTION STANDARDS

    E-print Network

    WM'02 Conference, February 24-28, 2002, Tucson, AZ ENVIRONMENTAL RADIATION PROTECTION STANDARDS Mountain Standards Office of Radiation and Indoor Air (6608J) U.S. Environmental Protection Agency radiation protection standards for the potential spent nuclear fuel and high-level radioactive waste

  15. October 2013AZ1606 The reasons for using vines in the landscape are many and

    E-print Network

    Wong, Pak Kin

    October 2013AZ1606 The reasons for using vines in the landscape are many and varied. First of all. Climbing over an arbor, vines give quick shade for patios and other outdoor living spaces. Planted beside a house wall or window, vines offer a curtain of greenery, keeping temperaturescoolerinside

  16. Brown shrimp (Farfantepenaeus az-tecus) have an estuarine-depen-

    E-print Network

    147 Brown shrimp (Farfantepenaeus az- tecus) have an estuarine-depen- dent life history; recent shrimp studies in estuaries have focused on loss of marsh nurs- ery habitats (Peterson and Turner shrimp migrations and decrease overall habi- tat area for brown shrimp (Craig et al., 2005). The brown

  17. 76 FR 31933 - Tonto National Forest; AZ; Salt River Allotments Vegetative Management EIS

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-02

    ...Forest Service Tonto National Forest; AZ; Salt River Allotments Vegetative Management...The Project Area is located along the Salt River in Gila County, Arizona. DATES...ecosystems within the six allotments along the Salt River. The purpose of this effort is...

  18. Influence of geometry on galvanic corrosion of AZ91D coupled to steel

    Microsoft Academic Search

    Jimmy X. Jia; Guangling Song; Andrej Atrens

    2006-01-01

    The influence of geometric factors on the galvanic current density distribution for AZ91D coupled to steel was investigated using experimental measurements and a BEM model. The geometric factors were area ratio of anode\\/cathode, insulation distance between anode and cathode, depth of solution film covering the galvanic couple and the manner of interaction caused by two independent interacting galvanic couples. The

  19. Waste Toolkit A-Z How can I reduce magazine waste?

    E-print Network

    Melham, Tom

    Waste Toolkit A-Z Magazines How can I reduce magazine waste? Your department may already recycle unwanted magazines, journals and other publications that regularly come into your building. It's good the carbon footprint of manufacturing and transporting the journals to you), by reducing magazine

  20. 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

  1. 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

  2. AzTEC 1.1 mm OBSERVATIONS OF THE MBM12 MOLECULAR CLOUD

    E-print Network

    Kim, M. J.; Kim, S.; Youn, S.; Yun, M. S.; Wislon, Graham W.; Aretxaga, I.; Williams, J. P.; Hughes, D. H.; Humphrey, A.; Austermann, J. E.; Perera, T. A.; Mauskopf, P. D.; Magnani, L.; Kang, Y. W.

    2012-01-19

    6.34 deg2 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 Az...

  3. 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...

  4. Optimization of a Wear Property of Die Cast AZ91D Components via a Neural Network

    Microsoft Academic Search

    Jeong-Lian Wen; Jie-Ren Shie; Yung-Kuang Yang

    2009-01-01

    This study integrated a trained general regression neural network (GRNN) and a sequential quadratic programming (SQP) method to determine an optimal parameter setting for a die casting process of AZ91D. Nine experiments were prepared under different die casting processes by selecting slurry pressure, the fusion slurry velocity and the mold temperature as three controlled parameters and the wear mass loss

  5. Tank 241-AZ-101 steam bumping and settling Process Test report

    SciTech Connect

    Winkler, C.M.

    1995-12-04

    This report summarizes the process test in which the airlift circulators in Tank 241-AZ-101 were shutdown. The test was successful, in that no extreme temperature excursions occurred. Only general data was obtianed through the use of a gamma energy probe.

  6. 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 to be recycled. While this is better than sending waste to landfill, there is a more sustainable way to recycle and parks. See examples of Tidy Planet's customers recycling on-site: www.tidyplanet.co.uk/our-news Short

  7. 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.

  8. Effect of deep cryogenic treatment on microstructure, creep and wear behaviors of AZ91 magnesium alloy

    Microsoft Academic Search

    Kaveh Meshinchi Asl; Alireza Tari; Farzad Khomamizadeh

    2009-01-01

    This paper focuses on the effect of deep cryogenic treatment (?196°C) on microstructure and mechanical properties of AZ91 magnesium alloy. The execution of deep cryogenic treatment on samples changed the distribution of ? precipitates. The tiny laminar ? particles almost dissolved in the microstructure and the coarse divorced eutectic ? phase penetrated into the matrix. This microstructural modification resulted in

  9. Dry sliding wear behaviour of plasma electrolytic oxidation coated AZ91 cast magnesium alloy

    Microsoft Academic Search

    P. Bala Srinivasan; C. Blawert; W. Dietzel

    2009-01-01

    A cast AZ91 magnesium alloy was plasma electrolytic oxidation (PEO) coated using a pulsed unipolar power source in a silicate based electrolyte. Constant processing conditions for two different durations were chosen to obtain coatings of 10 and 20?m thickness. The dry sliding wear studies performed on this alloy with and without PEO coatings against an AISI 52100 steel ball counterpart

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

    Microsoft Academic Search

    Teats

    1995-01-01

    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.

  11. Superplastic behaviour of friction stir processed AZ91 magnesium alloy produced by high pressure die cast

    Microsoft Academic Search

    P. Cavaliere; P. P. De Marco

    2007-01-01

    The room temperature and hot tensile properties of AZ91 magnesium alloy produced by high pressure die cast after friction stir processing (FSP) were studied in the present paper. Such process is a modification of classical friction stir welding one in which the sheets are not joined but the stirring action of the tool, on the bulk material, is used to

  12. Effect of surface nanocrystallization on the microstructural and corrosion characteristics of AZ91D magnesium alloy

    Microsoft Academic Search

    M. Laleh; Farzad Kargar

    2011-01-01

    Surface distinct deformed layers with thicknesses up to 150?m, with grain size in the top most surface is in the nanometer scale, were produced on AZ91D magnesium alloy using surface mechanical attrition treatment (SMAT). Effects of different ball size on the properties of the SMATed samples were investigated. The microstructural, grain size, hardness and roughness features of the treated surfaces

  13. 78 FR 33703 - Safety Zone; Great Western Tube Float; Colorado River; Parker, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-05

    ...safety zone on the navigable waters of the Colorado River in Parker, Arizona...is held on the navigable waters of the Colorado River in Parker, AZ. This...will include all navigable waters of the Colorado River from La Paz...

  14. Waste Toolkit A-Z How can I reduce waste envelopes?

    E-print Network

    Melham, Tom

    waste envelopes by using internal envelopes; reusing envelopes and where appropriate, switching from with metal or polystyrene (they go in the waste bin). Or reuse Jiffy envelopes so you buy less. ContactWaste Toolkit A-Z Envelopes How can I reduce waste envelopes? Departments and colleges can reduce

  15. Forming limit of AZ31 alloy sheet and strain rate on warm sheet metal forming

    Microsoft Academic Search

    Y. S. Lee; Y. N. Kwon; S. H. Kang; S. W. Kim; J. H. Lee

    2008-01-01

    The warm formability of AZ31 sheet has affected with strain rate as well as temperature because elongations are changed by the temperature and strain rate at an elevated temperature. Therefore, the formability must be investigated with the effects of both strain rate and temperature. In this study, the effects of temperature and strain rate were investigated on square cup drawing

  16. Experimental and analytical studies for forming limit of AZ31 alloy on warm sheet metal forming

    Microsoft Academic Search

    Y. S. Lee; M. C. Kim; S. W. Kim; Y. N. Kwon; S. W. Choi; J. H. Lee

    2007-01-01

    Since magnesium alloy sheet usually exhibits poor press formability, the sheet forming for complex shaped part has many difficult problems. Among these problems, the die design to prevent some defects is one of the important process variables. Therefore, the data for forming limit of AZ31 sheet is necessary to prevent the defect and get the good formed part. In this

  17. Mechanical And Microstructural Aspects Of High Temperature Formability Of AZ31 Sheets

    Microsoft Academic Search

    S. Spigarelli; E. Evangelista; M. El Mehtedi; L. Balloni

    2007-01-01

    The high temperature formability of AZ31 magnesium alloy sheets has been investigated in the temperature from 150 to 350°C. The different straining conditions have been studied by using sheet blanks with several length to width ratios, and Forming Limit Diagrams were then obtained. As expected, an increase in temperature was observed to enhance the formability of the alloy. These differences

  18. Dry Sliding Wear Behavior of Fly Ash Cenosphere/AZ91D Mg Alloy Composites

    NASA Astrophysics Data System (ADS)

    Yu, S. R.; Huang, Z. Q.

    2014-10-01

    Fly ash cenosphere/AZ91D Mg alloy (FAC/AZ91D) composites were prepared using stir casting method. The effects of the applied load, the wearing time, and the diameter and the content of fly ash cenosphere on the wear behavior of the composites were investigated under dry sliding condition. The results showed the wear resistance of FAC/AZ91D composites is generally better than that of AZ91D Mg alloy. The mass fraction and diameter of FAC have important effects on the wear resistance of the composites, and the wear resistance of the composites is excellent when the mass fraction and diameter of FAC are moderate. When the mass fraction and diameter of FAC are more than the critical values, the wear resistance of the composites lowers again. The wear resistance of the composites decreases with the increase in the applied load. The relationship between the worn mass loss and the applied load is nonlinear. When the applied load is smaller, the worn mass loss of the composites increases rapidly with the increase of the applied load. These research results show that the composites have broad application prospects under dry sliding wear condition, and they can provide guidance for the selection of the raw materials, the structure design, and the application conditions of the composites.

  19. Detroit : open city

    E-print Network

    Berry, Daniel (Daniel Kevin)

    2006-01-01

    Detroit is often regarded as America's largest city in decline, a metropolis that has failed to recover from an insidious cycle of deindustrialization, racism, suburban flight and laggard politics. This image of the city ...

  20. 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.

  1. A-Z International/Exchange Student Guide (So your Bishop's Experience is easier)

    E-print Network

    Laval University Quebec City, Canada RESEARCH INTERESTS Computational models of Human Communication. Computer vision and systems laboratory, Laval University 1998-1999 Research Assistant Quebec city, Canada

  2. 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.

  3. Acetylation of Vertebrate H2A.Z and Its Effect on the Structure of the Nucleosome†

    PubMed Central

    Ishibashi, Toyotaka; Dryhurst, Deanna; Rose, Kristie L.; Shabanowitz, Jeffrey; Hunt, Donald F.; Ausió, Juan

    2010-01-01

    Purified histone H2A.Z from chicken erythrocytes and a sodium butyrate-treated chicken erythroleukemic cell line was used as a model system to identify the acetylation sites (K4, K7, K11, K13, and K15) and quantify their distribution in this vertebrate histone variant. To understand the role played by acetylation in the modulation of the H2A.Z nucleosome core particle (NCP) stability and conformation, an extensive analysis was conducted on NCPs reconstituted from acetylated forms of histones, including H2A.Z and recombinant H2A.Z (K/Q) acetylation mimic mutants. Although the overall global acetylation of core histones destabilizes the NCP, we found that H2A.Z stabilizes the NCP regardless of its state of acetylation. Interestingly and quite unexpectedly, we found that the change in NCP conformation induced by global histone acetylation is dependent on H2A/H2A.Z acetylation. This suggests that acetylated H2A variants act synergistically with the acetylated forms of the core histone complement to alter the particle conformation. Furthermore, the simultaneous occurrence of H2A.Z and H2A in heteromorphic NCPs that most likely occurs in vivo slightly destabilizes the NCP, but only in the presence of acetylation. PMID:19385636

  4. CITY III Director's Guide.

    ERIC Educational Resources Information Center

    Envirometrics, Inc., Washington, DC.

    CITY III is a computer-assisted simulation game which allows the participants to make decisions affecting various aspects of the economic, governmental, and social sectors of a simulated urban area. The game director selects one of five possible starting city configurations, may set a number of conditions in the city before the start of play, and…

  5. Skills in the city

    Microsoft Academic Search

    Marigee Bacolod; Bernardo S. Blum; William C. Strange

    2009-01-01

    This paper documents the allocation of skills across cities and estimates the impact of agglomeration on the hedonic prices of worker skills. We find that large cities are more skilled than are small cities, but only to a modest degree. We also show that the increase in productivity associated with agglomeration, as measured by the urban wage premium, is larger

  6. 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

  7. 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

    ...details of the Lucas Oil Drag Boat Racing Series were not finalized nor presented to the Coast Guard in enough time to draft and publish an NPRM. As such...for The Lucas Oil Drag Boat Racing Series. This safety zone is necessary...

  8. 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.

  9. 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 ...

  10. 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.

  11. 76 FR 15936 - Designation for the Owensboro, KY; Bloomington, IL; Iowa Falls, IA; Casa Grande, AZ; Fargo, ND...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-22

    ...for the Owensboro, KY; Bloomington, IL; Iowa Falls, IA; Casa Grande, AZ; Fargo, ND...Inspection, Inc. (Central Illinois); Central Iowa Grain Inspection Service, Inc. (Central Iowa); Farwell Commodity and Grain Services,...

  12. 76 FR 62760 - Foreign-Trade Zone 277-Western Maricopa County, AZ; Application for Temporary/Interim...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-11

    ...Sub-Zero, Inc.; (Refrigerators); Goodyear, AZ An application has been submitted...Sub-Zero), facility, located in Goodyear, Arizona. The application was filed...the Palm Valley 303 Industrial Park in Goodyear, Arizona (Site 3). Under T/IM...

  13. Regulation of histone H2A.Z expression is mediated by sirtuin 1 in prostate cancer.

    PubMed

    Baptista, Tiago; Graça, Inęs; Sousa, Elsa J; Oliveira, Ana I; Costa, Natália R; Costa-Pinheiro, Pedro; Amado, Francisco; Henrique, Rui; Jerónimo, Carmen

    2013-10-01

    Histone variants seem to play a major role in gene expression regulation. In prostate cancer, H2A.Z and its acetylated form are implicated in oncogenes' upregulation. SIRT1, which may act either as tumor suppressor or oncogene, reduces H2A.Z levels in cardiomyocytes, via proteasome-mediated degradation, and this mechanism might be impaired in prostate cancer cells due to sirtuin 1 downregulation. Thus, we aimed to characterize the mechanisms underlying H2A.Z and SIRT1 deregulation in prostate carcinogenesis and how they interact. We found that H2AFZ and SIRT1 were up- and downregulated, respectively, at transcript level in primary prostate cancer and high-grade prostatic intraepithelial neoplasia compared to normal prostatic tissues. Induced SIRT1 overexpression in prostate cancer cell lines resulted in almost complete absence of H2A.Z. Inhibition of mTOR had a modest effect on H2A.Z levels, but proteasome inhibition prevented the marked reduction of H2A.Z due to sirtuin 1 overexpression. Prostate cancer cells exposed to epigenetic modifying drugs trichostatin A, alone or combined with 5-aza-2'-deoxycytidine, increased H2AFZ transcript, although with a concomitant decrease in protein levels. Conversely, SIRT1 transcript and protein levels increased after exposure. ChIP revealed an increase of activation marks within the TSS region for both genes. Remarkably, inhibition of sirtuin 1 with nicotinamide, increased H2A.Z levels, whereas activation of sirtuin 1 by resveratrol led to an abrupt decrease in H2A.Z. Finally, protein-ligation assay showed that exposure to epigenetic modifying drugs fostered the interaction between sirtuin 1 and H2A.Z. We concluded that sirtuin 1 and H2A.Z deregulation in prostate cancer are reciprocally related. Epigenetic mechanisms, mostly histone post-translational modifications, are likely involved and impair sirtuin 1-mediated downregulation of H2A.Z via proteasome-mediated degradation. Epigenetic modifying drugs in conjunction with enzymatic modulators are able to restore the normal functions of sirtuin 1 and might constitute relevant tools for targeted therapy of prostate cancer patients. PMID:24127549

  14. Hybrid laser–TIG welding, laser beam welding and gas tungsten arc welding of AZ31B magnesium alloy

    Microsoft Academic Search

    Liu Liming; Wang Jifeng; Song Gang

    2004-01-01

    Welding of AZ31B magnesium alloy was carried out using hybrid laser–TIG (LATIG) welding, laser beam welding (LBW) and gas tungsten arc (TIG) welding. The weldability and microstructure of magnesium AZ31B alloy welded using LATIG, LBW and TIG were investigated by OM and EMPA. The experimental results showed that the welding speed of LATIG was higher than that of TIG, which

  15. The effect of manganese on the precipitation of Mg 17 Al 12 phase in magnesium alloy AZ 91

    Microsoft Academic Search

    Y. Tamura; Y. Kida; H. Tamehiro; N. Kono; H. Soda; A. McLean

    2008-01-01

    Non-uniform continuous precipitation of the ?-phase is known to occur within the solution-treated grains of AZ91 alloys during\\u000a aging. In the present study, the segregation profiles of solute elements in the as-cast, solution heat-treated, and aged specimens\\u000a of AZ91E were examined by electron probe micro analysis. The results were correlated with optical and SEM observations of\\u000a the microstructures. It was

  16. Characterization and wear resistance of macro-arc oxidation coating on magnesium alloy AZ91 in simulated body fluids

    Microsoft Academic Search

    Jun CHEN; Rong-chang ZENG; Wei-jiu HUANG; Zi-qing ZHENG; Zhen-lin WANG; Jun WANG

    2008-01-01

    The mechanical characteristics of the macro-arc oxidation (MAO) coating on Mg alloy AZ91 were examined by means of nano scratch tester. The corrosion and erosion corrosion behavior of AZ91 with and without MAO coating were investigated by using potentiodynamic electrochemical technique and micro-abrasion tribometer in simulated body fluids, respectively. The influence of HCO3? ions on the erosion corrosion was discussed.

  17. Tribological Behavior of AZ91D Magnesium Alloy against SAE52100 Steel under Ionic Liquid Lubricated Conditions

    Microsoft Academic Search

    Yanqiu Xia; Zhengfeng Jia; Junhong Jia

    \\u000a The friction and wear properties of AZ91D magnesium alloy discs sliding against SAE52100 steel balls were evaluated using\\u000a an Optimol SRV reciprocating friction and wear tester under the lubrication of several ionic liquids. The morphologies of\\u000a the worn surfaces of the AZ91D magnesium alloy discs were observed using a scanning electron microscope (SEM). In addition,\\u000a the elemental compositions and chemical

  18. 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.

  19. Study on hydrogen removal of AZ91 alloys using ultrasonic argon degassing process.

    PubMed

    Liu, Xuan; Zhang, Zhiqiang; Hu, Wenyi; Le, Qichi; Bao, Lei; Cui, Jianzhong; Jiang, Jiajia

    2015-09-01

    Argon degassing, ultrasonic degassing and a novel ultrasonic argon degassing treatment were applied for the hydrogen removal of AZ91 magnesium alloy. The hydrogen concentration, microstructures and mechanical properties have also been investigated. AZ91 alloys contains a high hydrogen concentration. The mechanical properties of the as-cast alloy are much improved using degassing process, which should be mainly attributed to the hydrogen removal. Among the three degassing process, the ultrasonic argon treatment is a high efficient process both for hydrogen removal and microstructure refining. One hand, ultrasonic wave could break up the purged argon bubble to improve the degassing efficiency of these bubbles. On the other hand, ultrasound could also generate many cavitation bubbles in the melt, which should account for the microstructure refinement. The ultrasonic argon treatment involves dynamics between the ascending argon bubbles and ultrasonic effects, such as cavitation and streaming, etc. PMID:25649834

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

    PubMed Central

    2012-01-01

    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. Results We mapped H2A.Z genome-wide in mammalian ES cells and neural progenitors. H2A.Z is deposited promiscuously at promoters and enhancers, and correlates strongly with H3K4 methylation. Accordingly, H2A.Z is present at poised promoters with bivalent chromatin and at active promoters with H3K4 methylation, but is absent from stably repressed promoters that are specifically enriched for H3K27 trimethylation. We also characterized post-translational modification states of H2A.Z, including a novel species dually-modified by ubiquitination and acetylation that is enriched at bivalent chromatin. Conclusions Our findings associate H2A.Z with functionally distinct genomic elements, and suggest that post-translational modifications may reconcile its contrasting locations and roles. PMID:23034477

  1. Mutations in non-acid patch residues disrupt H2A.Z's association with chromatin through multiple mechanisms.

    PubMed

    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

  2. Mexico City, Mexico

    NASA Technical Reports Server (NTRS)

    1989-01-01

    In this rare clear view of Mexico City, Mexico (19.5N, 99.0W), the network of broad avenues and plazas of the capital city are very evident. The city, built on the remnants of a lake in the caldera of a tremendous extinct volcano, is home to over twenty million people and is slowly sinking as subsidence takes it's toll on the lakebed.

  3. Formability testing of AZ31B magnesium alloy tube at elevated temperature

    Microsoft Academic Search

    Zhubin He; Shijian Yuan; Gang Liu; Jia Wu; Weiwei Cha

    2010-01-01

    Magnesium alloy is a promising material for reaching the goal of weight reduction in automotive and aerospace industry. The mechanical properties of AZ31B seamless tube were tested by ring hoop tension test and compared with the results by axial tension test. Hydro-bulge test and newly proposed flatten-hydro-bulge test were also carried out to evaluate the formability of the tube. The

  4. 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

  5. Evaluation results for the positive deep-UV resist AZ DX 46

    NASA Astrophysics Data System (ADS)

    Spiess, Walter; Lynch, Thomas J.; Le Cornec, Charles; Escher, Gary C.; Kinoshita, Yoshiaki; Kochan, John; Kudo, Takanori; Masuda, Seiya; Mourier, Thierry; Nozaki, Yuko; Olson, Setha G.; Okazaki, Hiroshi; Padmanaban, Munirathna; Pawlowski, Georg; Przybilla, Klaus J.; Roeschert, Horst; Suehiro, Natusmi; Vinet, Francoise; Wengenroth, Horst

    1994-05-01

    This contribution emphasizes resist application site by communicating lithographic results for AZ DX 46, obtained using the GCA XLS 7800/31 stepper, NA equals 0.53, equipped with krypton fluoride excimer laser ((lambda) equals 248 nm), model 4500 D, as exposure source, delivered by Cymer Laser Technologies. As far as delay time experiments are concerned ASM-L PAS 5500/70 stepper, NA equals 0.42, was used in combination with Lambda Physik excimer laser, model 248 L.

  6. Eutectic bonding of austenitic stainless steel 316L to magnesium alloy AZ31 using copper interlayer

    Microsoft Academic Search

    Waled M. Elthalabawy; Tahir I. Khan

    2011-01-01

    The eutectic bonding of magnesium alloy (AZ31) to austenitic stainless steel alloy (316L) was performed using pure Cu interlayers.\\u000a The effect of hold time on the microstructural developments across the joint region and the related effect on bond shear strength\\u000a were studied at a bonding temperature of 530°C. The bonding process took place through a sequential occurrence of solid-state\\u000a diffusion

  7. Improved wear resistance of magnesium alloys AZ91 by high current pulsed electron beam treatment

    Microsoft Academic Search

    Mincai Li; Shengzhi Hao; Chuang Dong

    2009-01-01

    Surface modification of magnesium alloy AZ91 by high current pulsed electron beam (HCPEB) was investigated in the present\\u000a work. After irradiated by HCPEB, crater-like defects were found scattering on the modified surface, when increasing pulse\\u000a number, the density of craters sharply reduced. According to XRD analysis, hard intermetallic phase Mg17Al12 would sappear after several pulse of HCPEB treatment that is

  8. Wear Mechanism for In Situ TiC Particle Reinforced AZ91 Magnesium Matrix Composites

    Microsoft Academic Search

    Junping YaoWen; Wen Li; Lei Zhang; Fajun Wang; Mingshan Xue; Hongliu Jiang; Jinshan Lu

    2010-01-01

    TiC reinforced AZ91 magnesium matrix composites have been fabricated by a melt in situ reaction spray deposition. The microstructures\\u000a of spray-deposited alloys were studied by using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The dry sliding\\u000a wear behavior of the alloys was investigated by using a pin-on-disc machine under five loads, namely 10, 20, 30, 40, and 50 N.\\u000a The

  9. Sliding wear map for the magnesium alloy Mg9Al0.9 Zn (AZ91)

    Microsoft Academic Search

    H Chen; A. T Alpas

    2000-01-01

    Dry sliding wear tests were performed on a Mg-9.0%, Al-0.9%, Zn (AZ91) alloy using a block on-ring (AISI 52100 steel) configuration. Wear rates were measured within a load range of 1–350N and a sliding velocity range of 0.1–2.0m\\/s Compositions, morphologies and microstructures of worn surfaces and wear debris were characterised by scanning electron microscope (SEM), energy dispersive X-ray spectrometer (EDS)

  10. Effects of grain size on the wear of recycled AZ91 Mg

    Microsoft Academic Search

    M. Shanthi; C. Y. H. Lim; L. Lu

    2007-01-01

    Magnesium alloy AZ91 chips have been recycled using mechanical milling to yield samples with fine grain sizes. Together with cast samples of the same alloy, the wear behavior of these materials was studied through pin-on-disc sliding, with speeds varying from 1 to 10ms-1, under a normal load of 10N. Despite the differences in grain size (0.6–28.9?m) and mechanical properties, the

  11. The sliding wear behavior of TiC p \\/AZ91 magnesium matrix composites

    Microsoft Academic Search

    K. Xiu; H. Y. Wang; H. L. Sui; Y. Wang; C. L. Xu; J. G. Wang; Q. C. Jiang

    2006-01-01

    The AZ91 metal matrix composites (MMCs) reinforced with 5, 10 and 15 wt.% TiC particulates are fabricated by TiCp–Al master alloy process combined with mechanical stirring. The effects of TiC particulate content, applied load and wearing time on the sliding wear behaviors of the composites were investigated using MM-200 wear testing apparatus. The results show that the wear resistance and friction

  12. Galvanic corrosion properties of differently PVD-treated magnesium die cast alloy AZ91

    Microsoft Academic Search

    H. Hoche; C. Blawert; E. Broszeit; C. Berger

    2005-01-01

    Different types of PVD coatings and plasma treatments were applied for the surface treatment of magnesium die cast alloy AZ91 specimens. The different types of surface treatment were all developed by the authors and the fundamental properties are described elsewhere. The coating systems were:•9 ?m CrN hard coating•3 ?m TiN coating•0.5 ?m plasma anodisation layer and 3 ?m Al2O3 coatingThe

  13. Tribological properties of heat-treated electroless Ni–P coatings on AZ91 alloy

    Microsoft Academic Search

    M. Novák; D. Vojtech; P. Novák; T. Vítu

    2011-01-01

    Influence of heat treatment regime on adhesion and wear resistance of Ni–P electroless coating on AZ91 magnesium alloy is investigated in this work. The pretreated substrate was plated using a bath containing nickel sulphate, sodium hypophosphite and sodium acetate as main constituents. The coated samples were heat treated at 400–450°C for 1–8h. Adhesion of coating was estimated from the scratch

  14. Preparation and corrosion resistance studies of zirconia coating on fluorinated AZ91D magnesium alloy

    Microsoft Academic Search

    Qing Li; Xiankang Zhong; Junying Hu; Wei Kang

    2008-01-01

    Novel anti-corrosion zirconia coating was prepared via the sol–gel method for AZ91D magnesium alloy using zirconium nitrate hydrate as a precursor modified with acetylacetone (AcAc). Magnesium alloy substrates were first fluorinated in 20% HF aqueous solution at room temperature for 20h, then, the zirconia coating was deposited on the fluorinated sample by dip coating. Basing on the sol–gel process, a

  15. Novel hybrid sol–gel coatings for corrosion protection of AZ31B magnesium alloy

    Microsoft Academic Search

    S. V. Lamaka; M. F. Montemor; A. F. Galio; M. L. Zheludkevich; C. Trindade; L. F. Dick; M. G. S. Ferreira

    2008-01-01

    This work aims to develop and study new anticorrosion films for AZ31B magnesium alloy based on the sol–gel coating approach.Hybrid organic–inorganic sols were synthesized by copolymerization of epoxy-siloxane and titanium or zirconium alkoxides. Tris(trimethylsilyl) phosphate was also used as additive to confer additional corrosion protection to magnesium-based alloy. A sol–gel coating, about 5-?m thick, shows good adhesion to the metal

  16. Evaluation of AY\\/AZ tank farm ventilation system during aging waste retrieval operations

    Microsoft Academic Search

    J. J. Wong; E. D. Waters

    1995-01-01

    Waste Management is currently planning to demonstrate mobilization of radioactive waste sludges in Tank 101-AZ beginning in October 1991. The retrieval system being designed will utilize mixer pumps that generate high-velocity, high-volume submerged liquid jets to mobilize settled solids. There is concern that these jets may also generate radioactive aerosols, some of which may be carried into the tank Ventilation

  17. Fatigue behaviour of friction stir processed AZ91 magnesium alloy produced by high pressure die casting

    Microsoft Academic Search

    P.. Cavaliere; P. P. De Marco

    2007-01-01

    The room temperature fatigue properties of AZ91 magnesium alloy produced by high pressure die casting (HPDC) as cast, heat treated, friction stir processed (FSP) and FSP and heat treated were studied. The fatigue properties of the material were evaluated for the HPDC magnesium alloy in the as-received state and after a solution treatment at 415 °C for 2 h and an ageing

  18. Surface nanocrystallization of magnesium alloy AZ91D by high-energy shot peening

    Microsoft Academic Search

    Jin Zhang; Xingbin Ou; Donghua Yang; Zhifu Sun

    2009-01-01

    High-energy shot peening (HESP), a method to produce severe plastic deformation by high velocity flying balls, was applied\\u000a on die cast magnesium alloy AZ91D. Effects of surface nanocrystallization by HESP and heat treatment at different temperatures\\u000a were investigated. The microstructure evolution was conducted using X-ray diffraction (XRD) and field emission scanning electronic\\u000a microscopy (FESEM). The hardness was measured by microhardness

  19. Analyses of deformation twinning in the extruded magnesium alloy AZ31 after compressive and cyclic loading

    Microsoft Academic Search

    Michael Huppmann; Martin Lentz; Sarkis Chedid; Walter Reimers

    2011-01-01

    The influence of different loading conditions on the microstructural development of extruded magnesium alloy AZ31 was investigated\\u000a by optical microscopy and electron backscattered diffraction. Extruded magnesium profiles exhibit a significant asymmetry\\u000a in the mechanical properties, due to the low activation energy of the extension twinning system $$ \\\\left\\\\{ {10\\\\overline{1} 2} \\\\right\\\\}\\\\langle {10\\\\overline{1} 1}\\\\rangle,$$ when compressing along the extrusion direction. For

  20. Effect of warm forming conditions on AZ31B flow behaviour and microstructural characteristics

    Microsoft Academic Search

    Daniele Pellegrini; Andrea Ghiotti; Stefania Bruschi

    2011-01-01

    The paper presents the mechanical and microstructural characterization of the magnesium alloy AZ31B through tests conducted\\u000a at elevated temperature on a dedicated uni-axial tensile set-up. The samples are heated in-situ through induction heating\\u000a and their actual deformation is recorded in-line through the Aramis™ system. Results from the tests in terms of flow stress,\\u000a plastic properties and anisotropic coefficients are presented

  1. Air bending of AZ31 magnesium alloy in warm and hot forming conditions

    Microsoft Academic Search

    C. Bruni; A. Forcellese; F. Gabrielli; M. Simoncini

    2006-01-01

    The effect of the process parameters on springback of AZ31 magnesium alloy was investigated by performing air bending tests under warm and hot forming conditions. To this purpose, air bending experiments were carried out in the temperature range varying from 100 to 400°C, with different values of the punch speed (0.45 and 4.5mm\\/s). Also the influence of the punch radius

  2. Microstructure phenomena and mechanical properties of AZ31B under warm forming conditions

    Microsoft Academic Search

    D. Pellegrini; A. Ghiotti; S. Bruschi

    2009-01-01

    The paper presents the mechanical characterization of the magnesium alloy AZ31B at elevated temperature carried out on a dedicated\\u000a uni-axial tensile set-up. The samples are heated in-situ through induction heating and their deformation recorded in-line\\u000a through the Aramis™ system. Results from the tests in terms of plastic properties, anisotropic coefficients, hardening and\\u000a strain rate sensitivity exponents are presented and commented.

  3. 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

  4. Warm negative incremental forming of magnesium alloy AZ31 Sheet: New lubricating method

    Microsoft Academic Search

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

    2010-01-01

    The present study has been undertaken in order to investigate the suitable lubricants and lubricating methods, which can be employed to form a magnesium alloy AZ31 sheet by warm negative incremental forming (NIF). For the intended purpose, Nano-K2Ti4O9 whisker and organic binder were employed to improve the bonding strength at lubrication coating\\/sheet interface and lubricating properties at elevated temperatures. The

  5. Twinning, grain orientation and texture variation of AZ31 Mg alloy during compression by EBSD tracing

    Microsoft Academic Search

    Guang-Sheng Song; Shi-Hong Zhang; Li Zheng; Liqun Ruan

    2011-01-01

    In order to investigate the micro-mechanism of warm forming of Mg alloys, three specimens cut from a rolled AZ31 sheet were chosen to be compressed along the Rolling Direction (RD) at 100°C, 170°C and 230°C, separately. During compression, an in situ measurement of grain orientation in the plane of RD×TD (Transverse Direction) was carried out with EBSD method. Experimental and

  6. Experimental and numerical study of warm deep drawing of AZ31 magnesium alloy sheet

    Microsoft Academic Search

    Qun-Feng Chang; Da-Yong Li; Ying-Hong Peng; Xiao-Qin Zeng

    2007-01-01

    Warm forming of magnesium alloy sheet has attracted more and more attention in recent years. The formability of magnesium alloy sheet at elevated temperature depends on appropriate processes, and the fabrication of high-performance sheet. In this research, an AZ31 magnesium alloy sheet with excellent performances is fabricated by the cross-rolling and the uniform annealing treatments. The uniaxial tensile tests are

  7. Modelling of formula for flow stress of a magnesium alloy AZ31 sheet at elevated temperatures

    Microsoft Academic Search

    H. Takuda; T. Morishitaa; T. Kinoshita; N. Shirakawa

    2005-01-01

    For the evaluation of flow stress of a magnesium-based alloy AZ31 sheet in warm forming processes, a formula is derived by analysing the stress–strain curves measured under various temperatures and strain rates in this study. The formula is expressed in a simple form with the work-hardening exponent, n, the strain rate sensitivity exponent, m, and the stress coefficient, K. And

  8. Microstructure and Microtexture Formation of AZ91D Magnesium Alloys Solidified in a Static Magnetic Field

    Microsoft Academic Search

    Mingjun Li; Takuya Tamura; Kenji Miwa

    2009-01-01

    In the present study, we solidified AZ91D magnesium alloys in a static magnetic field with a magnetic flux density up to 10 Tesla\\u000a (T). Three different regions can be identified in a solidified alloy, according to their microtexture and microstructure;\\u000a these regions are: (a) region (A), the central region with equiaxed dendrites, (b) region (B), the transitional region with\\u000a directional dendrites

  9. 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.

  10. 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.; Elliott, M.L.

    1996-10-01

    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 were 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 was 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.

  11. H2A.Z helps genes remember their history so we can remember ours.

    PubMed

    Zovkic, Iva B; Walters, Brandon J

    2015-06-01

    Histone variant exchange is a novel epigenetic regulator of cognition. We speculate that H2A.Z, a variant of canonical histone H2A, exerts unique effects on transcription during distinct stages of memory formation, ultimately acting to maintain memory of previous transcriptional states and poise genes for re-activation. Hippocampus-dependent memory formation is initiated by transient expression of memory-related genes, which support the storage of recently acquired memories. Soon after, memories undergo systems consolidation, which transfers memories from the hippocampus to the cortex for long-term storage, and requires ongoing re-activation of memory-related genes. We speculate that learning-induced H2A.Z eviction from nucleosomes initially contributes to stimulus-induced transcriptional induction needed for the initial process of memory consolidation. During systems consolidation, we speculate that delayed incorporation of H2A.Z into nucleosomes of memory-related genes in the cortex is needed to poise genes for rapid re-activation, thus supporting the long-term process of memory stabilization. Also watch the Video Abstract. PMID:25880368

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

    NASA Astrophysics Data System (ADS)

    Chen, Fuh-Kuo; Chang, Chih-Kun

    2005-08-01

    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.

  13. 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,

  14. Histone chaperone Anp32e removes H2A.Z from DNA double-strand breaks and promotes nucleosome reorganization and DNA repair.

    PubMed

    Gursoy-Yuzugullu, Ozge; Ayrapetov, Marina K; Price, Brendan D

    2015-06-16

    The repair of DNA double-strand breaks (DSBs) requires open, flexible chromatin domains. The NuA4-Tip60 complex creates these flexible chromatin structures by exchanging histone H2A.Z onto nucleosomes and promoting acetylation of histone H4. Here, we demonstrate that the accumulation of H2A.Z on nucleosomes at DSBs is transient, and that rapid eviction of H2A.Z is required for DSB repair. Anp32e, an H2A.Z chaperone that interacts with the C-terminal docking domain of H2A.Z, is rapidly recruited to DSBs. Anp32e functions to remove H2A.Z from nucleosomes, so that H2A.Z levels return to basal within 10 min of DNA damage. Further, H2A.Z removal by Anp32e disrupts inhibitory interactions between the histone H4 tail and the nucleosome surface, facilitating increased acetylation of histone H4 following DNA damage. When H2A.Z removal by Anp32e is blocked, nucleosomes at DSBs retain elevated levels of H2A.Z, and assume a more stable, hypoacetylated conformation. Further, loss of Anp32e leads to increased CtIP-dependent end resection, accumulation of single-stranded DNA, and an increase in repair by the alternative nonhomologous end joining pathway. Exchange of H2A.Z onto the chromatin and subsequent rapid removal by Anp32e are therefore critical for creating open, acetylated nucleosome structures and for controlling end resection by CtIP. Dynamic modulation of H2A.Z exchange and removal by Anp32e reveals the importance of the nucleosome surface and nucleosome dynamics in processing the damaged chromatin template during DSB repair. PMID:26034280

  15. CESIUM REMOVAL FROM TANKS 241AN103 & 241SX105 & 241-AZ-101\\/102 COMPOSITE FOR TESTING IN BENCH SCALE STEAM REFORMER

    Microsoft Academic Search

    DUNCAN JB; HUBER HJ

    2011-01-01

    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

  16. Growth in Cities

    Microsoft Academic Search

    Edward Ludwig Glaeser; Hedi D. Kallal; Jose A. Scheinkman; Andrei Shleifer

    1992-01-01

    Recent theories of economic growth, including those of Romer, Porter, and Jacobs, have stressed the role of technological spillovers in generating growth. Because such knowledge spillovers are particularly effective in cities, where communication between people is more extensive, data on the growth of industries in different cities allow us to test some of these theories. Using a new data set

  17. Build a City.

    ERIC Educational Resources Information Center

    Reynolds, Jean A.

    1985-01-01

    A week-long build-a-city project is described which lets students become familiar with the history of the five Platonic solids (tetrahedron, octahedron, hexahedron, isosahedron, dodecahedron) and then use these solids to create a city using posterboard and construction paper. (MNS)

  18. Lost City News Release

    NSDL National Science Digital Library

    Office of Legislative and Public Affairs

    This press release from the National Science Foundation provides an overview of the 2003 expedition to the Lost City Hydrothermal Field at the Atlantis Massif. It briefly describes the expedition, features of the Lost City, research results and implications for future discoveries. Photos and images accompany the text.

  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. 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

  1. 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.

  2. Histone Variant H2A.Z Marks the 5? Ends of Both Active and Inactive Genes in Euchromatin

    PubMed Central

    Raisner, Ryan M.; Hartley, Paul D.; Meneghini, Marc D.; Bao, Marie Z.; Liu, Chih Long; Schreiber, Stuart L.; Rando, Oliver J.; Madhani, Hiten D.

    2007-01-01

    Summary In S. cerevisiae, histone variant H2A.Z is deposited in euchromatin at the flanks of silent heterochromatin to prevent its ectopic spread. We show that H2A.Z nucleosomes are found at promoter regions of nearly all genes in euchromatin. They generally occur as two positioned nucleosomes that flank a nucleosome-free region (NFR) that contains the transcription start site. Astonishingly, enrichment at 5? ends is observed not only at actively transcribed genes but also at inactive loci. Mutagenesis of a typical promoter revealed a 22 bp segment of DNA sufficient to program formation of a NFR flanked by two H2A.Z nucleosomes. This segment contains a binding site of the Myb-related protein Reb1 and an adjacent dT:dA tract. Efficient deposition of H2A.Z is further promoted by a specific pattern of histone H3 and H4 tail acetylation and the bromodomain protein Bdf1, a component of the Swr1 remodeling complex that deposits H2A.Z. PMID:16239142

  3. Histone variant H2A.Z marks the 5' ends of both active and inactive genes in euchromatin.

    PubMed

    Raisner, Ryan M; Hartley, Paul D; Meneghini, Marc D; Bao, Marie Z; Liu, Chih Long; Schreiber, Stuart L; Rando, Oliver J; Madhani, Hiten D

    2005-10-21

    In S. cerevisiae, histone variant H2A.Z is deposited in euchromatin at the flanks of silent heterochromatin to prevent its ectopic spread. We show that H2A.Z nucleosomes are found at promoter regions of nearly all genes in euchromatin. They generally occur as two positioned nucleosomes that flank a nucleosome-free region (NFR) that contains the transcription start site. Astonishingly, enrichment at 5' ends is observed not only at actively transcribed genes but also at inactive loci. Mutagenesis of a typical promoter revealed a 22 bp segment of DNA sufficient to program formation of a NFR flanked by two H2A.Z nucleosomes. This segment contains a binding site of the Myb-related protein Reb1 and an adjacent dT:dA tract. Efficient deposition of H2A.Z is further promoted by a specific pattern of histone H3 and H4 tail acetylation and the bromodomain protein Bdf1, a component of the Swr1 remodeling complex that deposits H2A.Z. PMID:16239142

  4. Optimisation of city size.

    PubMed

    Laurila, Hannu

    2011-01-01

    Club theoretical analysis of migration between asymmetrical cities shows that centralised policy intervention is necessary to ensure the efficient allocation of people between cities. Administrative and economic measures are compared as policy instruments of central government. These instruments are found to differ in their effects on residential allocation and welfare. In particular, a lump-sum tax-transfer programme pools the welfare-creating potentials of cities, thus affecting the efficiency condition. Therefore, lump-sum tax-transfers are superior to both quantity rationing and Pigouvian taxes, and they also activate, rather than stabilise, migration. PMID:21584984

  5. Ultrasonic Examination of Double-Shell Tank 241-AZ-101. Examination Completed July 2007.

    SciTech Connect

    Pardini, Allan F.; Weier, Dennis R.

    2007-08-12

    AREVA NC Inc. (AREVA), under a contract from CH2M Hill Hanford Group (CH2M Hill), has performed an ultrasonic examination of selected portions of Double-Shell Tank 241-AZ-101. PNNL is responsible for preparing a report(s) that describes the results of the AREVA ultrasonic examinations. The purpose of this examination was to provide information that could be used to evaluate the integrity of the wall of the primary tank. The requirements for the ultrasonic examination of Tank 241-AZ-101 were to detect, characterize (identify, size, and locate), and record measurements made of any wall thinning, pitting, or cracks that might be present in the wall of the primary tank. Any measurements that exceed the requirements set forth in the Engineering Task Plan (ETP), RPP-Plan-27202 (Jensen 2005) and summarized on page 1 of this document, are to be reported to CH2M HILL and the Pacific Northwest National Laboratory (PNNL) for further evaluation. Under the contract with CH2M HILL, all data is to be recorded on electronic media and paper copies of all measurements are provided to PNNL for third-party evaluation. PNNL is responsible for preparing a report(s) that describes the results of the AREVA ultrasonic examinations. The results of the examination of Tank 241-AZ-101 have been evaluated by PNNL personnel. The ultrasonic examination consisted of two vertical 15-in.-wide scan paths over the entire height of the tank and the heat-affected zone (HAZ) of five vertical welds and one horizontal weld from Riser 89. The examination also included two vertical 15-in.-wide scan paths over the entire height of the tank from Riser 90. The examination was performed to detect any wall thinning, pitting, or cracking in the primary tank wall.

  6. 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.

  7. 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.

  8. 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 ...

  9. 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 ...

  10. 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.

  11. 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.

  12. Fabrication of (TiB 2 ? TiC) p \\/AZ91 magnesium matrix hybrid composite

    Microsoft Academic Search

    B. X. Ma; H. Y. Wang; Y. Wang; Q. C. Jiang

    2005-01-01

    Magnesium MMCs reinforced with TiB2?TiC particulates were fabricated successfully via a master alloy route using a low cost Al-Ti-B4C system as starting material system. Microstructural characterization of the (TiB2?TiC)\\/AZ91 composite shows relatively uniform distribution of TiB2 and TiC particulates in the matrix material. Moreover, the results show that the hardness and wear resistance of the composites are higher than those

  13. Microstructure Evolution and Deformation Feature of AZ31 Magnesium Alloy during Severe Plastic Deformation

    NASA Astrophysics Data System (ADS)

    Hou, Li-Feng; Wei, Ying-Hui; Shu, Xue-Feng

    A nanostructured surface layer was produced on commercially AZ31 magnesium alloy using surface mechanical attrition treatment (SMAT). The microstructure evolution and deformation feature along the depth of the treated surface layer were characterized by transmission electron microscope (TEM) investigations. The grain refinement process, accompanied by an increase in the surface layer, involves: the onset of twins; the formation of microbands associated with the dislocation slipping; the subdivision of microbands into low angle grains and then highly disoriented polygonal submicronic grains, and further breakdown into randomly oriented nanograins with progression of dynamic recrystallization.

  14. [Cities in peril, Mahgreb].

    PubMed

    Naciri, M

    1994-10-01

    The urban population has surpassed 50% in the Maghreb: first in Tunisia, followed by Algeria and Morocco. This phenomenon has greatly affected the distribution of power and the forms of its exercise in the political, social, and economic domain. The old city social strata are becoming extinct while city management is falling more and more under the control of cadres originally from rural areas. Urbanization is occurring at a slower pace than in other developing countries, however. In Morocco, the small- and medium-sized towns are growing at a faster rate than the cities. Their lack of infrastructure and services, like those that exist in the periphery of large cities, preoccupies the small- and medium-sized towns. The urban explosion is much more contained than its management is adapting. Legal and illegal housing will dominate the Moroccan city in the future. In the last decade, Moroccan authorities have tried to establish mechanisms to integrate populations in slums and illegal housing with the urban space. The Tunisians are also working on this. In Algeria, the rigid, urban formal management leaves no room to develop any type of housing. The problem of housing is even more grave here than the other 2 countries. Structural adjustment policies promote selling rather than renting houses. The government is not involved in social and health services. Algeria has a 2-tier society: a minority involved in the private sector and the majority who depends on the collapsing public sector which cannot meet the great needs of the poor. Persons with college degrees are unemployed in Algeria. One no longer knows how to build towns with the traditional medinas. The transportation system is falling apart in cities. Cities dump liquid and solid wastes directly into the sea or the wadis. The major risk of maghrebian cities lies in socioeconomic inequalities. PMID:12179396

  15. 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.

  16. 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

  17. 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

  18. Sinking Coastal Cities

    NASA Astrophysics Data System (ADS)

    Erkens, G.; Stuurman, R.; De Lange, G.; Bucx, T.; Lambert, J.

    2014-12-01

    In many coastal 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 continue to sink, even below sea level. The ever increasing industrial and domestic demand for water in these cities results in excessive groundwater extraction, causing severe subsidence. In addition, coastal cities are often faced with larger natural subsidence, as they are built on thick sequences of soft soil. The impacts of subsidence are further exacerbated by climate-induced sea level rise. Land subsidence results in two types damage: foremost it increases flood vulnerability (frequency, inundation depth and duration of floods), with floods causing major economic damage and loss of lives. Secondly, differential land movement causes significant economic losses in the form of structural damage and high maintenance costs of roads and transportation networks, sewage systems, buildings and foundations. The total damage worldwide is estimated at billions of dollars annually. To survey the extent of groundwater associated subsidence, we conducted a quick-assessment of subsidence in a series of mega-cities (Jakarta, Ho Chi Minh City, Dhaka, New Orleans and Bangkok). For each city research questions included: what are the main causes, how much is the current subsidence rate and what are predictions, where are the vulnerable areas, what are the impacts and risks, how can adverse impacts can be mitigated or compensated for, and what governmental bodies are involved and responsible to act? Using the assessment, this paper discusses subsidence modelling and measurement results from the selected cities. The focus is on the importance of delayed settlement after increases in hydraulic heads, the role of the subsurface composition for subsidence rates and best practice solutions for subsiding cities. For the latter, urban (ground)water management, adaptive flood risk management and related spatial planning strategies are just examples of the options available. The discussions in this paper form the building blocks for a much-needed research agenda that aims to deliver a strategy to deal with subsidence in current and future subsidence-prone areas.

  19. Room Temperature Shear Band Development in Highly Twinned Wrought Magnesium AZ31B Sheet

    NASA Astrophysics Data System (ADS)

    Scott, Jon; Miles, Michael; Fullwood, David; Adams, Brent; Khosravani, Ali; Mishra, Raja K.

    2013-01-01

    Failure mechanisms were studied in wrought AZ31B magnesium alloy after forming under different strain paths. Optical micrographs were used to observe the shear band formation and regions of high twin density in samples strained under uniaxial, biaxial, and plane strain conditions. Interrupted testing at 4 pct effective strain increments, until failure, was used to observe the evolution of the microstructure. The results showed that shear bands, with a high percentage of twinned grains, appeared early in the samples strained under biaxial or plane strain tension. These bands are similar to those seen in uniaxial tension specimens just prior to failure where the uniaxial tensile ductility was much greater than that observed for plane strain or biaxial tension conditions. A forming limit diagram for AZ31B, which was developed from the strain data, showed that plane strain and biaxial tension had very similar limit strains; this contrasts with materials like steel or aluminum alloys, which typically have greater ductility in biaxial tension compared to plane strain tension.

  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. 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 FORGEŽ. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Interfacial reaction in squeeze cast SiCw/AZ91 magnesium alloy composite

    SciTech Connect

    Wu, K.; Zheng, M.; Zhao, M.; Yao, C. [Harbin Inst. of Tech. (China). School of Materials Science and Engineering] [Harbin Inst. of Tech. (China). School of Materials Science and Engineering; Li, J. [Academic Sinica, Shengyang (China). Lab. of Atomic Imaging of Solids] [Academic Sinica, Shengyang (China). Lab. of Atomic Imaging of Solids

    1996-08-15

    It is well known that the interface between the matrix and the reinforcement plays an important role in the properties of metal matrix composites (MMCs). Interfacial structure and its effect on the properties of aluminum matrix composites have been extensively studied. The interface of Mg-MMCs is very different from that of Al-MMCs, due to high reactivity of magnesium. As magnesium have natural affinity for wetting or bonding to ceramic reinforcement, and furthermore, magnesium does not form any carbides, SiC is one of the most suitable reinforcement for magnesium matrix composite, SiCw/AZ91 magnesium matrix composites have excellent properties compared with other discontinuously reinforced Mg-MMCs. The aim of the present study is to investigate the interfacial reactions in SiCw/AZ91 composites prepared by squeeze casting method, with particular emphasis on the morphology, structure and the formation mechanisms of the reaction products using electron microscopy, in order to provide a better understanding of the relationship between the interfacial structure and the properties of the composites.

  6. 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%.

  7. A MOBIL INTERNET TECHNOLÓGIAI, GAZDASĂGI ÉS TĂRSADALMI HATĂSAI AZ AGRĂRGAZDASĂGBAN

    Microsoft Academic Search

    Robert Szilagyi; Miklos Herdon

    2005-01-01

    A mobil kommunikáció, ezen belül a mobil Internet az agrárgazdaság számá-ra a használat hely és idő függetlensége miatt fontos lehetőséget, gazdasági elő-nyöket, a vállalkozások, szervezetek számára hatékonyabb működést jelenthet. Széleskörű elterjedése, innovációs hatása és előnyei gazdaságosan csak a technológia és a szolgáltatások hatásrendszerének figyelembevételével érhető el. A technológiai, társadalmi és gazdasági komplex hatásrendszer befolyásolja a gazdasági alkalmazások terjedését. Az alkalmazható

  8. 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.

  9. Ultrafine particles in cities.

    PubMed

    Kumar, Prashant; Morawska, Lidia; Birmili, Wolfram; Paasonen, Pauli; Hu, Min; Kulmala, Markku; Harrison, Roy M; Norford, Leslie; Britter, Rex

    2014-05-01

    Ultrafine particles (UFPs; diameter less than 100 nm) are ubiquitous in urban air, and an acknowledged risk to human health. Globally, the major source for urban outdoor UFP concentrations is motor traffic. Ongoing trends towards urbanisation and expansion of road traffic are anticipated to further increase population exposure to UFPs. Numerous experimental studies have characterised UFPs in individual cities, but an integrated evaluation of emissions and population exposure is still lacking. Our analysis suggests that the average exposure to outdoor UFPs in Asian cities is about four-times larger than that in European cities but impacts on human health are largely unknown. This article reviews some fundamental drivers of UFP emissions and dispersion, and highlights unresolved challenges, as well as recommendations to ensure sustainable urban development whilst minimising any possible adverse health impacts. PMID:24503484

  10. 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.

  11. Life in the City

    NSDL National Science Digital Library

    This fun Web site is part of OLogy, where kids can collect virtual trading cards and create projects with them. Here, they take a close-up look at biodiversity in a city park. The site opens by telling kids that, despite appearances, a great deal of biodiversity exists in cities. From tiny mites to mighty trees, thousands of species thrive there. It then takes them to a slice of life from a thriving city park, where they are asked to find 10 hidden critters living alongside the trees, plants, and insects. Each time they locate one of the tiny critters, they are rewarded with a quick look at its importance to the habitat.

  12. 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.

  13. 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 melters (CCM). #12;WM '04 Conference, February 29 ­ March 4, 2004, Tucson, AZ WM-4010 JOULE HEATED CERAMIC for a reference liquid radioactive waste with total salt content about 200 g/l [2- 5]. Fig. 1 Joule heated ceramic

  14. Comparison of the microstructure and thermal stability of an AZ31 alloy processed by ECAP and large strain hot rolling

    Microsoft Academic Search

    M. Eddahbi; J. A. del Valle; M. T. Pérez-Prado; O. A. Ruano

    2005-01-01

    The aim of this work is to compare the microstructure, the texture, as well as the thermal stability of an AZ31 Mg alloy processed via two different severe plastic deformation processing techniques, namely large strain hot rolling (LSHR) and equal channel angular pressing (ECAP). The microstructure was characterized by optical microscopy and the texture was measured both by X-ray diffraction

  15. 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

  16. "Accidental" Urban Wetland Networks along the Salt River in Phoenix, AZ Monica M. Palta, Nancy B. Grimm

    E-print Network

    Hall, Sharon J.

    wetland networks have formed in the bed of the otherwise dry Salt River, fed by outfalls carrying storm"Accidental" Urban Wetland Networks along the Salt River in Phoenix, AZ Monica M. Palta, Nancy B in drought frequency and storm severity in Phoenix: - Drier conditions increase erosion by water during storm

  17. 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.

  18. AzTEC half square degree survey of the SHADES fields – I. Maps, catalogues and source counts

    E-print Network

    Austermann, J. E.; Dunlop, J. S.; Perera, Thushara A.; Scott, K. S.; Wilson, Graham Wallace; Aretxaga, I.; Hughes, D. H.; Almaini, O.; Chapin, E. L.; Chapman, S. C.; Cirasuolo, M.; Clements, D. L.; Coppin, K. E. K.; Dunne, L.; Dye, S.; Eales, S. A.; Egami, E.

    2010-01-01

    We present the first results from the largest deep extragalactic mm-wavelength survey undertaken to date. These results are derived from maps covering over 0.7 deg^(2), made at ?= 1.1 mm, using the AzTEC continuum camera mounted on the James Clerk...

  19. 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...

  20. Modeling texture evolution during rolling process of AZ31 magnesium alloy with elasto-plastic self consistent model

    Microsoft Academic Search

    Shi-yao HUANG; Shao-rui ZHANG; Da-yong LI; Ying-hong PENG

    2011-01-01

    To gain a better understanding about texture evolution during rolling process of AZ31 alloy, polycrystalline plasticity model was implemented into the explicit FE package, ABAQUS\\/Explicit by writing a user subroutine VUMAT. For each individual grain in the polycrystalline aggregate, the rate dependent model was adopted to calculate the plastic shear strain increment in combination with the Voce hardening law to

  1. A Crystalline Plasticity Finite Element Method for Simulation of the Plastic Deformation of AZ31 Magnesium Alloys

    Microsoft Academic Search

    Dayong Li; Shaorui Zhang; Weiqin Tang; Shiyao Huang; Yinghong Peng

    2010-01-01

    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

  2. AzTEC/ASTE 1.1-mm survey of the AKARI Deep Field South: source catalogue and number counts

    E-print Network

    Hatsukade, B.; Kohno, K.; Aretxaga, I.; Austermann, J. E.; Ezawa, H.; Hughes, D. H.; Ikarashi, S.; Iono, D.; Kawabe, R.; Khan, S.; Matsuo, H. v; Matsuura, S.; Nakanishi, K.; Oshima, T.; Perera, T.; Scott, K. S.; Shirahata, M.; Takeuchi, T. T.; Tamura, Y.; Tanaka, K.; Tosaki, T.; Wilson, Graham Wallace; Yun, M. S.

    2011-02-11

    We present results of a 1.1-mm deep survey of the AKARI Deep Field South (ADF-S) with AzTEC mounted on the Atacama Submillimetre Telescope Experiment (ASTE). We obtained a map of 0.25-deg2 area with an rms noise level of 0.32–0.71 mJy. This is one...

  3. Influence of shot peening on high cycle fatigue properties of the high-strength wrought magnesium alloy AZ80

    Microsoft Academic Search

    P. Zhang; J. Lindemann

    2005-01-01

    The influence of shot peening on fatigue performance of the high-strength wrought magnesium alloy AZ80 was investigated. Shot peening effectively improved the fatigue life: an improvement of 60% in the fatigue strength was obtained at the optimum condition. In addition, the magnesium alloy reacted sensitively to shot peening. This sensitivity was attributed to the limited deformability of the hexagonal crystal

  4. Computational microstructure analyzing technique for quantitative characterization of shrinkage and gas pores in pressure die cast AZ91 magnesium alloys

    Microsoft Academic Search

    D. G. Leo Prakash; B. Prasanna; D. Regener

    2005-01-01

    Pressure die cast AZ91 magnesium alloy contains both shrinkage and gas microporosity. Quantification and characterization of shrinkage and gas microporosity is expected to be useful to understand the processing-properties-microstructure correlations. However, conventional image analysis techniques do not permit a separate quantification and characterization of shrinkage and gas microporosity. A computational microstructural (image) analyzing technique has been developed by the use

  5. a Process Map for Sequential Compression-Backward Extrusion of AZ31 MG Alloys at Warm Temperaturs

    Microsoft Academic Search

    Duk-Jae Yoon; Eung-Zoo Kim; Chong-Du Cho; Yong-Shin Lee

    2008-01-01

    This paper is concerned with development of a process map for sequential compression-backward extrusion of bulk AZ31 Mg alloy at the warm temperatures. In experiments, metal flows and crack initiations are carefully investigated and formability is examined systematically for various forming conditions such as forming temperature, punch speed, and a gap between a specimen and die. Then, a process map

  6. 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.

  7. Temporal Regulation of Foregut Development by HTZ-1/H2A.Z and PHA-4/FoxA

    E-print Network

    Mango, Susan

    Temporal Regulation of Foregut Development by HTZ-1/H2A.Z and PHA-4/FoxA Dustin L. Updike, Susan EA transcription factor PHA-4 to coordinate temporal gene expression during foregut development. We observe dramatic genetic interactions between pha-4 and htz-1, mys-1, and ssl-1. A survey of transcription factors

  8. City of Castle Hills State of the City and Recommendations

    E-print Network

    Bright, Elise; Croxell, Christina

    2003-01-01

    Two courses focused on assessing the demographics, economics, environment, aesthetics, land use, transportation, and city history. Newspaper articles, maps, Census Data, field trip, examination of the city budget, planning efforts, and zoning were...

  9. City of Castle Hills State of the City and Recommendations 

    E-print Network

    Bright, Elise; Croxell, Christina

    2003-01-01

    Two courses focused on assessing the demographics, economics, environment, aesthetics, land use, transportation, and city history. Newspaper articles, maps, Census Data, field trip, examination of the city budget, planning efforts, and zoning were...

  10. Development and validation of the Pediatric AzBio sentence lists

    PubMed Central

    Spahr, Anthony J.; Dorman, Michael F.; Litvak, Leonid M.; Cook, Sarah; Loiselle, Louise M.; DeJong, Melissa D.; Hedley-Williams, Andrea; Sunderhaus, Linsey S.; Hayes, Catherine A.; Gifford, René H.

    2014-01-01

    Objectives The goal of this study was to create and validate a new set of sentence lists that could be used to evaluate the speech perception abilities of listeners with hearing loss in cases where adult materials are inappropriate due to difficulty level or content. Our intention was to generate a large number of sentence lists with an equivalent level of difficulty for the evaluation of performance over time and across conditions. Design The original Pediatric-AzBio sentence corpus included 450 sentences recorded from one female talker. All sentences included in the corpus were successfully repeated by kindergarten and first grade students with normal hearing. The mean intelligibility of each sentence was estimated by processing each sentence through a cochlear implant simulation and calculating the mean percent correct score achieved by 15 normal-hearing listeners. After sorting sentences by mean percent correct scores, 320 sentences were assigned to 16 lists of equivalent difficulty. List equivalency was then validated by presenting all sentence lists, in a novel random order, to adults and children with hearing loss. A final-validation stage examined single-list comparisons from adult and pediatric listeners tested in research or clinical settings. Results The results of the simulation study allowed for the creation of 16 lists of 20 sentences. The average intelligibility of each list ranged from 78.4% to 78.7%. List equivalency was then validated, when the results of 16 adult cochlear implant users and 9 pediatric hearing aid and cochlear implant users revealed no significant differences across lists. The binomial distribution model was used to account for the inherent variability observed in the lists. This model was also used to generate 95% confidence intervals for one and two list comparisons. A retrospective analysis of 361 instances from 78 adult cochlear implant users and 48 instances from 36 pediatric cochlear implant users revealed that the 95% confidence intervals derived from the model captured 94% of all responses (385/409). Conclusions The cochlear implant simulation was shown to be an effective method for estimating the intelligibility of individual sentences for use in the evaluation of cochlear implant users. Further the method used for constructing equivalent sentence lists and estimating the inherent variability of the materials has also been validated. Thus, the AzBio Pediatric Sentence Lists are equivalent and appropriate for the assessment of speech understanding abilities of children with hearing loss as well as adults for whom performance on AzBio sentences is near the floor. PMID:24658601

  11. 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

  12. SPECIAL MEETING AGENDA CITY COUNCIL OF THE CITY OF CERRITOS

    E-print Network

    on this Agenda are available for public inspection at the City Clerk's Office, Cerritos City Hall, 18125 of the agenda packet are available for public inspection in the City Clerk's Office at the above address during), this project is exempt from CEQA review. B. A proposal by Yesco Signs, LLC, on behalf of the Cerritos Auto

  13. 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/).

  14. 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.

  15. 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.

  16. 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…

  17. 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…

  18. 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…

  19. CITY COUNCIL Margaret Connell

    E-print Network

    Commission 1516 Ninth Street Sacramento, CA 95814-5514 RE: Local Building Energy Efficiency Standards Dear commitment to have the City of Goleta enforce the current Title 24 Building Energy Efficiency Standards Energy Efficiency Standards (Title 24, part 6) of the California Building Code. The language reflects

  20. The New City Commons

    ERIC Educational Resources Information Center

    Crossland, Janice

    1975-01-01

    Cities throughout the country are sponsoring family projects that convert vacant lots and rooftops to productive neighborhood gardens. It is hoped that utilization of these otherwide wasted areas will provide extra food for low income families, as well as promote community spirit and organization. (MA)

  1. Industrial Development in Cities

    Microsoft Academic Search

    Vernon Henderson; Ari Kuncoro; Matt Turner

    1995-01-01

    This paper uses data for eight manufacturing industries to test for and characterize dynamic production externalities in cities. The authors find evidence of both Marshall-Arrow-Romer (MAR) externalities, which are associated with past own industry employment concentration, and Jacobs externalities, which are associated with past diversity of local total employment. For mature capital goods industries, there is evidence of MAR externalities

  2. Utah: Salt Lake City

    Atmospheric Science Data Center

    2014-05-15

    ... mountains surrounding Salt Lake City are renowned for the dry, powdery snow that results from the arid climate and location at the ... should be used with the red filter placed over your left eye. The canyons and peaks of the Uinta and Wasatch Mountains are ...

  3. Global / globalizing cities.

    PubMed

    Yeoh, B S

    1999-01-01

    Along with the rise in research on globalization, the concept of globalization has become a subject to a more critical scrutiny. While majority agree that it represents a serious challenge to the state-centrist assumptions of most previous social science, doubts about its newness, inevitability and epoch-making qualities are also being raised. Others argue that the globalization literature neglects issues of social regulation by the nation-state, while some critics view it as a discourse drawn upon to legitimize particular political and economic agendas. Debates focus on metropolitan manifestations and impacts. Moving from this background, the paper presents three sociospatial urban configurations that have emerged in the literature. Alongside attempts at identifying globalizing cities and transnational urban networks as new theoretical subjects, another significant vein in the literature focuses on the complex forces of globalization and the production of new urban spaces in these cities. In addition, economic conceptions of globalization is now being pushed beyond adding sociocultural or sociopolitical dimensions and argue instead for the need to theorize globalization as a discursive formation. The global city as a discursive category conjures up imaginary concepts of high modernity, megadevelopment, 21st century urbanity. However, it is noted that the way forward is to focus on the distinctive ways in which urban actors engage in specific processes of economic and social reflexivity. There exists an urgent task for theorizations of the global city, which weave together historical, economic, cultural, sociopolitical and discursive dimensions. PMID:12296126

  4. 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.

  5. Kipple kaboodle : reincarnating California city

    E-print Network

    Pho, Susanna Wansan

    2015-01-01

    California City is a superlative shrinking suburb. Situated deep in the Mojave Desert, the conditions that typically spur suburban shrinkage are exaggerated here. As such, the city provides a singular opportunity to comment ...

  6. Participating Agencies City of Barrie

    E-print Network

    Toronto, University of

    of Kawartha Lakes City of Peterborough City of Toronto County of Dufferin County of Peterborough County of Simcoe County of Wellington GO Transit Ministry of Transportation Ontario Regional Municipality of Durham

  7. Effect of preheat on TIG welding of AZ61 magnesium alloy

    NASA Astrophysics Data System (ADS)

    Shen, Jun; Xu, Nan

    2012-04-01

    The effects of preheat treatments on the microstructures and mechanical properties of tungsten inert gas (TIG)-welded AZ61 magnesium alloy joints were studied by microstructural observations, microhardness tests and tensile tests. The results showed that the volume fraction of the lamellar ?-Mg17(Al,Zn)12 intermetallic compound of in fusion zone (FZ) increased from 15% to 66% with an increase in preheat temperature. Moreover, the microhardness of the FZ and the ultimate tensile strength of the welded joints reached their maximum values when the preheat temperature was 300°C because more lamellar ?-Mg17(Al,Zn)12 intermetallic compounds were distributed at the ?-Mg grain boundaries and no cracks and pores formed in the FZ of the welded joint.

  8. Numerical analysis of self-pierce riveting of AZ31 magnesium alloy sheets

    NASA Astrophysics Data System (ADS)

    Han, S. L.; Wu, Y. W.; Zeng, Q. L.; Gao, Y.

    2013-05-01

    Magnesium alloy sheet has a broad development prospect for lightweight metal in automotive industry. Selfpierce Riveting (SPR) process is a suitable joining technology to fasten materials of different nature. This paper is concerned with the development of numerical models of the SPR process of AZ31 magnesium alloy sheet. Based on DEFORM-2D finite element software, a two-dimensional axisymmetric model has been built for the SPR process. Then the distribution of stress and strain, and the stroke-load curve are analyzed in the forming process of the riveting. After a 2D simulation of SPR process, the quality of riveted joint is evaluated in terms of joint cross-sectional shape. The results show a better understanding of mechanical properties of SPR joints of magnesium alloy sheets. As a sufficient interlock and bottom thickness leading to a reasonably good joint, the numerical simulation method plays a significant role to predict the final strength of the joint.

  9. Fatigue and material characteristics of a hot-formed AZ31 magnesium alloy

    NASA Astrophysics Data System (ADS)

    Suh, Chang-Min; Hor, Kwang-Ho; Nahm, Seung-Hoon; Suh, Min-Soo

    2015-03-01

    Magnesium alloys are known to be hard-forming materials at room temperature owing to their material structure. This study analyzes the optimal temperature conditions of warm-forming and the forming process by using a high-pressure laminating test and FM analysis, respectively. The effect of temperatures on the fatigue limit was examined from the collected specimens by analyzing the material properties after the fatigue test. The material formed at a temperature of 230°C shows occasional defects, but the best forming quality was obtained at 270°C. The optimal temperature for the forming process was found to be 250°C considering the material quality and thermal efficiency. The overall fatigue life of specimens decreases with an increase in the processing temperature. The fatigue limit of AZ31 formed at 250°C was approximately 100 MPa after 106 cycles.

  10. Die-casting effect on surface characteristics of thin-walled AZ91D magnesium components

    NASA Astrophysics Data System (ADS)

    Hu, Lifang; Chen, Shaoping; Miao, Yang; Meng, Qingsen

    2012-11-01

    Filling trace, filling time and temperature distribution during the die-casting process were simulated using commercial software (MAGMA). The surface microstructure and phase distribution in thin-walled AZ91D magnesium components cast on a hot-chamber die-casting machine were investigated by means of optical microscopy and scanning electron microscopy. The depth profile of alloying elements was examined using a glow discharge optical emission spectrometer. The outer skin microstructure consists of more ?-phase and less eutectic ?-phase than the interior region. The elemental content of C, Si, and Fe in the outer skin increased along the filling trace, and they decreased with increasing distance from the surface to the interior region, while the Al had an inverse trend. The corrosion resistance decreased along the filling trace.

  11. Cyclic Plasticity Constitutive Model for Uniaxial Ratcheting Behavior of AZ31B Magnesium Alloy

    NASA Astrophysics Data System (ADS)

    Lin, Y. C.; Liu, Zheng-Hua; Chen, Xiao-Min; Long, Zhi-Li

    2015-05-01

    Investigating the ratcheting behavior of magnesium alloys is significant for the structure's reliable design. The uniaxial ratcheting behavior of AZ31B magnesium alloy is studied by the asymmetric cyclic stress-controlled experiments at room temperature. A modified kinematic hardening model is established to describe the uniaxial ratcheting behavior of the studied alloy. In the modified model, the material parameter m i is improved as an exponential function of the maximum equivalent stress. The modified model can be used to predict the ratcheting strain evolution of the studied alloy under the single-step and multi-step asymmetric stress-controlled cyclic loadings. Additionally, due to the significant effect of twinning on the plastic deformation of magnesium alloy, the relationship between the material parameter m i and the linear density of twins is discussed. It is found that there is a linear relationship between the material parameter m i and the linear density of twins induced by the cyclic loadings.

  12. 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.

  13. 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.

  14. 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.

  15. Tribological properties of heat-treated electroless Ni-P coatings on AZ91 alloy

    NASA Astrophysics Data System (ADS)

    Novák, M.; Vojt?ch, D.; Novák, P.; Vít?, T.

    2011-09-01

    Influence of heat treatment regime on adhesion and wear resistance of Ni-P electroless coating on AZ91 magnesium alloy is investigated in this work. The pretreated substrate was plated using a bath containing nickel sulphate, sodium hypophosphite and sodium acetate as main constituents. The coated samples were heat treated at 400-450 °C for 1-8 h. Adhesion of coating was estimated from the scratch test with an initial load of 8.80 N. Wear resistance was studied using the pin-on-disc method. It was found that there is no significant dependence of the coating wear resistance on heat treatment regime, as the formation of Al-Ni intermetallic sub-layers that reduce coating adhesion is limited to regions where Al17Mg12 phase is present in the substrate. Moreover, the coating shows good sliding properties due to the formation of oxide glazes in the wear track.

  16. 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.

  17. Fatigue behaviour of friction stir processed AZ91 magnesium alloy produced by high pressure die casting

    SciTech Connect

    Cavaliere, P. [INFM-Dept. of 'Ingegneria dell'Innovazione', Engineering Faculty, University of Lecce, Via per Arnesano, 73100, Lecce (Italy)]. E-mail: pasquale.cavaliere@unile.it; De Marco, P.P. [INFM-Dept. of 'Ingegneria dell'Innovazione', Engineering Faculty, University of Lecce, Via per Arnesano, 73100, Lecce (Italy)

    2007-03-15

    The room temperature fatigue properties of AZ91 magnesium alloy produced by high pressure die casting (HPDC) as cast, heat treated, friction stir processed (FSP) and FSP and heat treated were studied. The fatigue properties of the material were evaluated for the HPDC magnesium alloy in the as-received state and after a solution treatment at 415 deg. C for 2 h and an ageing treatment at 220 deg. C for 4 h. The heat treatment resulted in a significant increase in the fatigue properties of the HPDC material, while no significance influence of heat treatment was recorded in the FSP condition. The morphology of fracture surfaces was examined by employing a field emission gun scanning electron microscope (FEGSEM)

  18. Microstructure, texture, and residual stress in a friction stir processed AZ31B magnesium alloy

    SciTech Connect

    Woo, Wan Chuck [ORNL; Choo, Hahn [ORNL; Feng, Zhili [ORNL; Clausen, B [Los Alamos National Laboratory (LANL); Prime, Michael B [ORNL

    2008-01-01

    Spatial variations of microstructure, hardness, chemical composition, tensile behavior, texture and residual stresses were investigated in a friction-stir-processed (FSP) AZ31B magnesium alloy. The residual stresses were measured using two different methods: neutron diffraction and the contour method. No significant variations in the hardness and chemical compositions were found in the FSP zones, including the severely deformed stir zone (SZ), which showed a finer grain size compared to the heat-affected zone and base material. On the other hand, significant changes in the tensile yield strength, texture, and residual stresses were observed in the FSP zones. The relationship between the texture variations and yield strength reduction; and its influence on the decrease in the residual stress near the SZ is discussed. Finally, the residual stresses measured by neutron diffraction and the contour method are compared and the effect of the texture on neutron diffraction residual stress measurements is discussed.

  19. Mechanical And Microstructural Aspects Of High Temperature Formability Of AZ31 Sheets

    SciTech Connect

    Spigarelli, S.; Evangelista, E.; El Mehtedi, M.; Balloni, L. [Dipartimento di Meccanica, Universita Politecnica delle Marche, 60131 Ancona (Italy)

    2007-04-07

    The high temperature formability of AZ31 magnesium alloy sheets has been investigated in the temperature from 150 to 350 deg. C. The different straining conditions have been studied by using sheet blanks with several length to width ratios, and Forming Limit Diagrams were then obtained. As expected, an increase in temperature was observed to enhance the formability of the alloy. These differences in formability observed in the warm- and hot-forming regions were related to the microstructural evolution during deformation. Optical microscopy revealed the occurrence of recrystallization, and the volume fraction of recrystallized microstructure was found to increase with temperature. FEM simulation of the Nakazima test were also obtained by using flow curves obtained in torsion between 100 and 400 deg. C as input data. Correlation between FEM modeling results and experimental data was considered to be excellent.

  20. 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.

  1. Texture, Second-Phase Particles, and the Anisotropy of Deformation Behavior in TTMP AZ61

    NASA Astrophysics Data System (ADS)

    Berman, Tracy D.; Pollock, Tresa M.; Jones, J. Wayne

    2015-07-01

    The deformation, damage accumulation, and fracture behavior of thixomolded and thermomechanically processed AZ61 were studied by room temperature uniaxial straining. The material was examined in as-molded, as-rolled, and rolled + annealed conditions. The yield strength and work hardening behavior are controlled primarily by grain size and crystallographic texture, which reaches a maximum of only 4.8 multiples of random density in the as-rolled material. The low degree of texture results in a low degree of plastic anisotropy (Lankford r value), suggesting good formability properties. In addition, it is shown that although the ?-phase particles begin to crack as early as 4 pct elongation, their presence does not lead to a decrease in ductility, as ?-phase cracks do not coalesce to initiate fracture.

  2. 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.

  3. 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.

  4. 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.

  5. City College Report to FIPSE.

    ERIC Educational Resources Information Center

    Tartter, Vivien C.

    In each of 3 years, 20 City College of New York undergraduates from New York City public inner city school backgrounds read to and mentored individual second graders in a Harlem public school in a program supported by the Department of Education's Fund for the Improvement of Postsecondary Education (FIPSE). Supporting academic experience aimed to…

  6. NEW YORK CITY NONPROFIT EXECUTIVE

    E-print Network

    Rosen, Jay

    NEW YORK CITY NONPROFIT EXECUTIVE OUTLOOK SURVEY SPONSORED BY THE SCHOOL OF PUBLIC AFFAIRS ARE SERVING MORE PEOPLE, DESPITE FINANCIAL PRESSURES AND ADVERSE GOVERNMENT FUNDING POLICIES #12;NEW YORK CITY YORK CITY FEDERATION OF PROTESTANT WELFARE AGENCIES UJA­FEDERATION OF NEW YORK UNITED NEIGHBORHOOD

  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. 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.

  9. 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...

  10. 78 FR 66267 - Safety Zone; HITS Triathlon Series; Colorado River; Lake Havasu, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-05

    ...HITS Triathlon Series; Colorado River; Lake Havasu...zone upon the navigable waters of the Colorado River in support of the...HITS Triathlon Series; Colorado River, Lake Havasu City...safety zone includes the waters in the northern...

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  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. 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.

  17. Freedomship: City At Sea

    NSDL National Science Digital Library

    Freedomship is an enormous floating city that will be a monument to engineering skill and ingenuity. It will serve as a vacation resort or even a home for people with enough money. Although still in the pre-construction phase of the project, the Web site offers a good deal of information about the ship's design. It will be almost a mile long and rise 25 stories above the water. The ship will accommodate around 40,000 visitors who can arrive by boat or plane (yes, there will even be a small airport on the top deck). When Freedomship is not moving, it will sit offshore near major cities and other popular tourist destinations. The Web site provides several artist renderings that tantalize the imagination. Freedomship will be featured on Engineering the Impossible on the Discovery Channel February 25th, 2002.

  18. Human diffusion and city influence.

    PubMed

    Lenormand, Maxime; Gonçalves, Bruno; Tugores, Antňnia; Ramasco, José J

    2015-08-01

    Cities are characterized by concentrating population, economic activity and services. However, not all cities are equal and a natural hierarchy at local, regional or global scales spontaneously emerges. In this work, we introduce a method to quantify city influence using geolocated tweets to characterize human mobility. Rome and Paris appear consistently as the cities attracting most diverse visitors. The ratio between locals and non-local visitors turns out to be fundamental for a city to truly be global. Focusing only on urban residents' mobility flows, a city-to-city network can be constructed. This network allows us to analyse centrality measures at different scales. New York and London play a central role on the global scale, while urban rankings suffer substantial changes if the focus is set at a regional level. PMID:26179991

  19. 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.

  20. Is a healthy city also an age-friendly city?

    PubMed

    Jackisch, Josephine; Zamaro, Gianna; Green, Geoff; Huber, Manfred

    2015-06-01

    Healthy Ageing is an important focus of the European Healthy Cities Network and has been supported by WHO since 2003 as a key strategic topic, since 2010 in cooperation with the Global Network of Age-friendly Cities and Communities. Based on the methodology of realist evaluation, this article synthesizes qualitative evidence from 33 structured case studies (CS) from 32 WHO European Healthy Cities, 72 annual reports from Network cities and 71 quantitative responses to a General Evaluation Questionnaire. City cases are assigned to three clusters containing the eight domains of an age-friendly city proposed by WHO's Global Age-friendly City Guide published in 2007. The analysis of city's practice and efforts in this article takes stock of how cities have developed the institutional prerequisites and processes necessary for implementing age-friendly strategies, programmes and projects. A content analysis of the CS maps activities across age-friendly domains and illustrates how cities contribute to improving the social and physical environments of older people and enhance the health and social services provided by municipalities and their partners. PMID:26069312

  1. FINAL REPORT DM1200 TESTS WITH AZ 101 HLW SIMULANTS VSL-03R3800-4 REV 0 2\\/17\\/04

    Microsoft Academic Search

    KRUGER AA; MATLACK KS; BARDAKCI T; DANGELO NA; GONG W; KOT WK; PEGG IL

    2011-01-01

    This report documents melter and off-gas performance results obtained on the DM 1200 HLW Pilot Melter during processing of simulated HLW AZ-101 feed. The principal objectives of the DM1200 melter testing were to determine the achievable glass production rates for simulated HLW AZ-101 feed; determine the effect of bubbling rate and feed solids content on production rate; characterize melter off-gas

  2. Wiener-folyamatok legfontosabb tulajdons'agai. Poisson-folyamatok. L'attuk, hogy a Wiener-folyamat teljes'iti az 'ugynevezett funkcion'alis centr'*

    E-print Network

    Major, PĂŠter

    -folyamat teljes'iti az 'ugynevezett funkcion'alis centr'* *alis hat'ar- eloszl'ast'etelt. Ez az eredm'eny durv teljes'itik a centr'alis hat'a* *reloszl'ast'etel fel- t'eteleit, akkor ezek r'eszlet"osszegeinek seg"uggetlen standard norm'alis eloszl'as'u val'osz'in"us'egi v'altoz'o. Ekkor W* * (t) = B(t) + tj Wiener

  3. 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

  4. Large cities are less green

    NASA Astrophysics Data System (ADS)

    Oliveira, Erneson A.; Andrade, José S.; Makse, Hernán A.

    2014-02-01

    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.

  5. Effects of heat input on the low power Nd:YAG pulse laser conduction weldability of magnesium alloy AZ61

    NASA Astrophysics Data System (ADS)

    Min, Dong; Shen, Jun; Lai, Shiqiang; Chen, Jie; Xu, Nan; Liu, Hui

    2011-01-01

    The effects of heat input on the low power Nd:YAG pulse laser conduction weldability of magnesium alloy AZ61 plates were investigated. The results show that for a hot-extruded AZ61 magnesium alloy plate laser conduction welding, the penetration depth and area of welds cross-section increased with an increase of the heat input. The microstructure of a band zone, which is located in the fusion zone (FZ) and close to the fusion boundary, evolved with an increase of the heat input. Moreover, an increase of the heat input increased the tendency of the formation of solidification cracking and liquation cracking. The porosities and average diameters of pores increased with an increase of the heat input but reduced sharply when a relatively large heat input was achieved. In addition, the degree of formation of craters increased linearly with an increase of the heat input.

  6. Investigations on the Stress and Strain Evolution in AZ91D Magnesium Alloy Castings During Hot Tearing

    NASA Astrophysics Data System (ADS)

    Bichler, L.; Ravindran, C.

    2015-03-01

    Hot tearing in magnesium and aluminum alloys has been rigorously investigated in the past decades. To date, the interactions between the solidification parameters, microstructural development, and stress and strain at the onset of hot tearing in magnesium alloys remain unclear. In particular, the stress and strain conditions required to nucleate hot tears are unknown. In this research, ex situ neutron diffraction residual strain mapping was carried out on AZ91D magnesium alloy castings at the onset of hot tearing. The results indicate that tensile strain alone was not sufficient to nucleate a hot tear. A minimum threshold tensile stress of 12 MPa was necessary to open interdendritic shrinkage pores into hot tears and enable their propagation. Further, deformation along (10overline{1} 1) and (10overline{1} 2) crystallographic planes played a dominant role on the high-temperature deformation and hot tearing in the AZ91D alloy.

  7. Microstructural Analysis of Severe Plastic Deformed Twin Roll Cast AZ31 for the Optimization of Superplastic Properties

    SciTech Connect

    Young, John P.; Askari, Hesam A.; Heiden, Michael J.; Hovanski, Yuri; Field, David P.; Zbib, Hussein M.

    2013-07-08

    In recent years magnesium alloys have attracted significant attention as potential candidates to replace many of the heavier metals used in some automotive applications. However, the limited formability of magnesium and its alloys at room temperature has driven interest in the superplastic forming magnesium as an alternative shaping method. Severe plastic deformation techniques have become a well studied method of refining the grain size and modifying the microstructural characteristics of many magnesium alloys to achieve greater superplastic properties. In this study twin roll cast (TRC) AZ31 magnesium alloy was subjected to equal channel angular pressing (ECAP) and friction stir welding (FSW). The influence of these severe plastic deformation processes on the grain size, texture and grain boundary character distribution was investigated to identify the optimum severe plastic deformation process for the superplastic forming of AZ31.

  8. 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.

  9. A Crystalline Plasticity Finite Element Method for Simulation of the Plastic Deformation of AZ31 Magnesium Alloys

    NASA Astrophysics Data System (ADS)

    Li, Dayong; Zhang, Shaorui; Tang, Weiqin; Huang, Shiyao; Peng, Yinghong

    2010-06-01

    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.

  10. CityGML-Interoperable Access to 3D City Models

    Microsoft Academic Search

    T. H. Kolbe

    2005-01-01

    Abstract. Virtual 3D city models provide important information for different aspects of disaster management. In this context, up-to-dateness of and flexible access to 3D city models are of utmost importance. Spatial Data Infrastructures (SDI) provide the appropriate framework ,to cover ,both aspects, integrating distributed data sources on demand. In this paper we present CityGML, a multi-purpose and multi-scale representation for

  11. Thermal stress analysis of fused-cast AZS refractories during production; Part 2: Development of thermo-elastic stress model

    Microsoft Academic Search

    Steven L. Cockcroft; J. Keith Brimacornbe; Dennis G. Walrod; Thomas A. Myles

    1994-01-01

    Mathematical models of heat flow and thermo-elastic stress, based on the finite-element method, have been developed and utilized to analyze the voidless,'' fused-cast, AZS, solidification process. The results of the mathematical analysis, in conjunction with information obtained in a comprehensive industrial study, presented in Part 1 of this paper, describe the mechanisms for the formation of the various crack types

  12. 241-AZ-101 Mixer Pump Demonstration Test Gamma Cart Acceptance Test Procedure and Quality Test Plan (ATP and QTP)

    SciTech Connect

    WHITE, D.A.

    2000-01-27

    Shop test of the sludge mobilization cart system to be used in the AZ-101 Mixer Pump Demonstration Test Tests hardware and software. This procedure involves testing the Instrumentation involved with the Gamma Cart System, local and remote, including depth indicators, speed controls, interface to data acquisition software and the raising and lowering functions. This Procedure will be performed twice, once for each Gamma Cart System. This procedure does not test the accuracy of the data acquisition software.

  13. 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.

  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?ą?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. 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

  16. Characterization of High Strain Rate Mechanical behavior of AZ31 magnesium alloy using 3D Digital Image Correlation

    Microsoft Academic Search

    Yanli Wang; Hanbing Xu; DONALD L ERDMAN; J Michael Starbuck; Srdjan Simunovic

    2011-01-01

    Characterization of the material mechanical behavior at sub-Hopkinson regime (0.1 to 1000 sš) is very challenging due to instrumentation limitations and the complexity of data analysis involved in dynamic loading. In this study, AZ31 magnesium alloy sheet specimens are tested using a custom designed servo-hydraulic machine in tension at nominal strain rates up to 1000 sš. In order to resolve

  17. CrN–TiN multilayer coating on magnesium alloy AZ91 by arc-glow plasma depositing process

    Microsoft Academic Search

    Q. Miao; C. E. Cui; J. D. Pan

    2007-01-01

    CrN–TiN multilayer films were deposited on magnesium alloy AZ91 by a novel method of arc-glow plasma depositing to improve its wear resistance. The total thickness of the coating was about 2 ?m with 12 sub-layers of CrN and TiN deposited alternately.The composition and microstructure of the coating layer were analyzed by means of X-ray diffraction (XRD) and glow discharge spectrum (GDS).

  18. The influence of ceramic particles on bond strength of cold spray composite coatings on AZ91 alloy substrate

    Microsoft Academic Search

    Qiang Wang; Kevin Spencer; Nick Birbilis; Ming-Xing Zhang

    2010-01-01

    Al–Al2O3 composite coatings were produced on AZ91D magnesium alloy substrates using kinetic metallization (KM), which is a special type of cold spray using a convergent barrel nozzle to attain sonic velocity. The effect of the volume fraction of Al2O3 particles and KM spray temperatures on the microstructure, hardness of the composite coatings, the deposition efficiency, and the bond strength between

  19. Corrosion behaviour of high pressure die-cast and semi-solid cast AZ91D alloys

    Microsoft Academic Search

    S Mathieu; C Rapin; J Hazan; P Steinmetz

    2002-01-01

    The microstructure and the corrosion behaviour of high pressure die-cast and semi-solid cast AZ91D magnesium alloys have been investigated. Semi-solid processing leads to a structure with large rounded grains of a solid solution of magnesium (? phase) whereas die-cast alloys are more homogeneous. Electrochemical measurements, particularly with impedance spectroscopy, have shown that the semi-solid cast alloy possesses a corrosion rate

  20. Application of YAG Laser TIG Arc Hybrid Welding to Thin AZ31B Magnesium Alloy Sheet

    NASA Astrophysics Data System (ADS)

    Kim, Taewon; Kim, Jongcheol; Hasegawa, Yu; Suga, Yasuo

    A magnesium alloy is said to be an ecological material with high ability of recycling and lightweight property. Especially, magnesium alloys are in great demand on account of outstanding material property as a structural material. Under these circumstances, research and development of welding process to join magnesium alloy plates are of great significance for wide industrial application of magnesium. In order to use it as a structure material, the welding technology is very important. TIG arc welding process is the most ordinary process to weld magnesium alloy plates. However, since the heat source by the arc welding process affects the magnesium alloy plates, HAZ of welded joint becomes wide and large distortion often occurs. On the other hand, a laser welding process that has small diameter of heat source seems to be one of the possible means to weld magnesium alloy in view of the qualitative improvement. However, the low boiling point of magnesium generates some weld defects, including porosity and solidification cracking. Furthermore, precise edge preparation is very important in butt-welding by the laser welding process, due to the small laser beam diameter. Laser/arc hybrid welding process that combines the laser beam and the arc is an effective welding process in which these two heat sources influence and assist each other. Using the hybrid welding, a synegistic effect is achievable and the disadvantages of the respective processes can be compensated. In this study, YAG laser/TIG arc hybrid welding of thin magnesium alloy (AZ31B) sheets was investigated. First of all, the effect of the irradiation point and the focal position of laser beam on the quality of a weld were discussed in hybrid welding. Then, it was confirmed that a sound weld bead with sufficient penetration is obtained using appropriate welding conditions. Furthermore, it was made clear that the heat absorption efficiency is improved with the hybrid welding process. Finally, the tensile tests of welded joints were performed, and it was confirmed that they have sufficient mechanical properties. As a result of this study, it is confirmed that, if the appropriate welding conditions are selected, sound welded joints of AZ31B magnesium alloy are obtainable by the YAG laser/TIG arc hybrid welding process.

  1. Effect of hot working on the damping capacity and mechanical properties of AZ31 magnesium alloy

    NASA Astrophysics Data System (ADS)

    Lee, K.; Kang, C.; Kim, K.

    2015-04-01

    Magnesium alloys have received much attention for their lightweight and other excellent properties, such as low density, high specific strength, and good castability, for use in several industrial and commercial applications. However, both magnesium and its alloys show limited room-temperature formability owing to the limited number of slip systems associated with their hexagonal close-packed crystal structure. It is well known that crystallographic texture plays an important role in both plastic deformation and macroscopic anisotropy of magnesium alloys. Many authors have concentrated on improving the room- temperature formability of Mg alloys. However, despite having a lot of excellent properties in magnesium alloy, the study for various properties of magnesium alloy have not been clarified enough yet. Mg alloys are known to have a good damping capacity compared to other known metals and their alloys. Also, the damping properties of metals are generally recognized to be dependent on microstructural factors such as grain size and texture. However, there are very few studies on the relationship between the damping capacity and texture of Magnesium alloys. Therefore, in this study, specimens of the AZ31 magnesium alloy, were processed by hot working, and their texture and damping property investigated. A 60 mm × 60 mm × 40 mm rectangular plate was cut out by machining an ingot of AZ31 magnesium alloy (Mg-3Al-1Zn in mass%), and rolling was carried out at 673 K to a rolling reduction of 30%. Then, heat treatment was carried out at temperatures in the range of 573-723 K for durations in the range of 30-180 min. The samples were immediately quenched in oil after heat treatment to prevent any change in the microstructure. Texture was evaluated on the compression planes by the Schulz reflection method using nickel-filtered Cu K? radiation. Electron backscatter diffraction measurements were conducted to observe the spatial distribution of various orientations. Specimens for damping capacity measurements were machined from the rolled specimen, to have a length of 120 mm, width of 20 mm, and thickness of 1 mm. The damping capacity was measured with a flexural internal friction measurement machine at room temperature. It was found that the damping capacity increases with both increasing heat-treatment temperature and time, due to grain growth and the increased pole densities of textures.

  2. 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 22ą1°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

  3. Laser surface forming of AlCoCrCuFeNi particle reinforced AZ91D matrix composites

    NASA Astrophysics Data System (ADS)

    Meng, Guanghui; Yue, T. M.; Lin, Xin; Yang, Haiou; Xie, Hui; Ding, Xu

    2015-07-01

    Traditionally, the laser melt injection (LMI) technique can only be used for forming ceramic particles reinforced metal matrix composites (MMCs) for enhancing surface properties of lightweight engineering materials. In this research, the LMI method was employed to form metal particles reinforced MMCs on AZ91D instead. This was viable because of the unique properties of the AlCoCrCuFeNi high-entropy alloy (HEA) metal particles used. The large difference in melting point between the HEA and the substrate material (AZ91D), and the limited reaction and the lack of fusion between the HEA and Mg have made it possible that a metal particles reinforced AZ91D composite material was produced. The reason of limited reaction was considered mainly due to the relatively high mixing enthalpy between the HEA constituent elements and Mg. Although there was some melting occurred at the particles surface with some solute segregation found in the vicinity close to the surface, intermetallic compounds were not observed. With regard to the wear resistance of the MMCs, it was found that when the volume fraction of the reinforcement phase, i.e. the HEA particles, reached about 0.4, the wear volume loss of the coating was only one-seventh of that of the substrate material.

  4. Constructing cities, deconstructing scaling laws.

    PubMed

    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

  5. The dynamics of city formation*

    PubMed Central

    Henderson, J. Vernon; Venables, Anthony J.

    2013-01-01

    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

  6. 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.

  7. 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).

  8. Smart Financing for Smart Cities 

    E-print Network

    Byrd, D.

    2014-01-01

    Index) Confidential Property of Schneider Electric ESL-KT-14-11-29 CATEE 2014: Clean Air Through Efficiency Conference, Dallas, Texas Nov. 18-20 From smart devices through to big data, we provide cities with services systems and , technology to... Property of Schneider Electric 10 resources Innovation ESL-KT-14-11-29 CATEE 2014: Clean Air Through Efficiency Conference, Dallas, Texas Nov. 18-20 Cities must become smarter a smart city strategically approaches technology with emphasis on sustainability...

  9. Smart Financing for Smart Cities

    E-print Network

    Byrd, D.

    2014-01-01

    Smart Financing for Smart Cities CATEE 2014 November 19 1 Drew Byrd City Leader, Schneider Electric ESL-KT-14-11-29 CATEE 2014: Clean Air Through Efficiency Conference, Dallas, Texas Nov. 18-20 Global energy consumption continues to rise... Digitization Economic Industrialization 3Confidential Property of Schneider Electric Rebalancing ESL-KT-14-11-29 CATEE 2014: Clean Air Through Efficiency Conference, Dallas, Texas Nov. 18-20 Today’s Agenda Cities and Our Future A N A h Why Cities Need Smart...

  10. City/Place Population Estimates

    NSDL National Science Digital Library

    1997-01-01

    The US Census Bureau has released updated population estimates for cities, places, and minor civil divisions in the US. Seven major sections list cities over 100,000 and 10,000 by rank and percent growth, as well as cities, places, and minor civil divisions. The latter three sections contain figures from 1990-1996; these are arranged by state and they are also available as aggregated .zip files. Documentation and file layout are available. This City/Place information is part of a larger Census population site that covers national, state, and metropolitan area estimates (discussed in the April 25, 1997 Scout Report).

  11. Single-molecule tools elucidate H2A.Z nucleosome composition

    PubMed Central

    Chen, Jiji; Miller, Andrew; Kirchmaier, Ann L.; Irudayaraj, Joseph M. K.

    2012-01-01

    Summary Although distinct epigenetic marks correlate with different chromatin states, how they are integrated within single nucleosomes to generate combinatorial signals remains largely unknown. We report the successful implementation of single molecule tools constituting fluorescence correlation spectroscopy (FCS), pulse interleave excitation-based Förster resonance energy transfer (PIE-FRET) and fluorescence lifetime imaging-based FRET (FLIM-FRET) to elucidate the composition of single nucleosomes containing histone variant H2A.Z (Htz1p in yeast) in vitro and in vivo. We demonstrate that yeast nucleosomes containing Htz1p are primarily composed of H4 K12ac and H3 K4me3 but not H3 K36me3 and that these patterns are conserved in mammalian cells. Quantification of epigenetic modifications in nucleosomes will provide a new dimension to epigenetics research and lead to a better understanding of how these patterns contribute to the targeting of chromatin-binding proteins and chromatin structure during gene regulation. PMID:22393239

  12. Semisolid die forging process, microstructures and properties of AZ31 magnesium alloy mobile telephone shells

    NASA Astrophysics Data System (ADS)

    Guan, Ren-Guo; Chen, Li-Qing; Cao, Fu-Rong; Zhao, Zhan-Yong; Ren, Yong

    2011-12-01

    A semisolid slurry of AZ31 magnesium alloy was prepared by vibrating wavelike sloping plate process, and the semisolid die forging process, microstructures, and properties of the magnesium alloy mobile telephone shell were investigated. The semisolid forging process was performed on a YA32-315 four-column universal hydraulic press. The microstructures were observed by optical microscopy, the hardness was analyzed with a model 450SVD Vickers hardometer, the mechanical properties was measured with a CMT5105 tensile test machine, and the fractograph of elongated specimens was observed by scanning electron microscopy (SEM). The results reveal that with the increase of die forging force, the microstructures of the product become fine and dense. A lower preheating temperature and a longer dwell time are favorable to the formation of fine and dense microstructures. The optimum process conditions of preparing mobile telephone shells with excellent surface quality and microstructures are a die forging force of 2000 kN, a die preheating temperature of 250°C, and a dwell time of 240 s. After solution treatment at 430°C and aging at 220°C for 8 h, the Vickers hardness is 61.7 and the ultimate tensile strength of the product is 193 MPa. Tensile fractographs show the mixing mechanisms of quasi-cleavage fracture and ductile fracture.

  13. Creep behavior of an AZ91 magnesium alloy reinforced with alumina fibers

    SciTech Connect

    Li, Y.; Langdon, T.G. [Univ. of Southern California, Los Angeles, CA (United States)

    1999-08-01

    Creep tests were conducted at elevated temperatures on an AZ91 alloy reinforced with 20 vol pct Al{sub 2}O{sub 3} fibers. When the creep data are interpreted by incorporating a threshold stress into the analysis, it is shown that the true stress exponent, n, is {approximately}3 at the lower stress levels and increases to >3 at the higher stresses. The true activation energy for creep is close to the value anticipated for interdiffusion of aluminum in magnesium. This behavior is interpreted in terms of a viscous glide process with n = 3 and a breakaway of the dislocations from their solute atom atmospheres at the higher stress levels. The threshold stresses in this composite appear to arise from an attractive interaction between mobile dislocations in the matrix alloy and Mg{sub 17}Al{sub 12} precipitates. The experimental results reveal several important similarities between the creep behavior of this magnesium-based composite and the well-documented creep properties of aluminum-based composites.

  14. 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.

  15. Microstructure and mechanical properties of AZ91 magnesium alloy subject to deep cryogenic treatments

    NASA Astrophysics Data System (ADS)

    Li, Gui-rong; Wang, Hong-ming; Cai, Yun; Zhao, Yu-tao; Wang, Jun-jie; Gill, Simon P. A.

    2013-09-01

    AZ91 magnesium alloy was subjected to a deep cryogenic treatment. X-ray diffraction (XRD), scanning electronic microscopy (SEM), and transmission electronic microscopy (TEM) methods were utilized to characterize the composition and microstructure of the treated samples. The results show that after two cryogenic treatments, the quantity of the precipitate hardening ? phase increases, and the sizes of the precipitates are refined from 8-10 ?m to 2-4 ?m. This is expected to be due to the decreased solubility of aluminum in the matrix at low temperature and the significant plastic deformation owing to internal differences in thermal contraction between phases and grains. The polycrystalline matrix is also noticeably refined, with the sizes of the subsequent nanocrystalline grains in the range of 50-100 nm. High density dislocations are observed to pile up at the grain boundaries, inducing the dynamic recrystallization of the microstructure, leading to the generation of a nanocrystalline grain structure. After two deep cryogenic treatments, the tensile strength and elongation are found to be substantially increased, rising from 243 MPa and 4.4% of as-cast state to 299 MPa and 5.1%.

  16. Growth and characterization of Mg(OH) 2 film on magnesium alloy AZ31

    NASA Astrophysics Data System (ADS)

    Zhu, Yanying; Wu, Guangming; Zhang, Yun-Hong; Zhao, Qing

    2011-05-01

    Magnesium-based biomaterials have been proposed as potential candidates for biodegradable implant materials, such as bone screws, bone plates, intraluminal stents and so on. However, the poor corrosion resistance inhibits their applications in surgery. They collapse before the injured tissues are healed. In this paper, Mg(OH) 2 nonstructural film was synthesized on the substrate of AZ31 magnesium alloy by hydrothermal method with NaOH solution as mineralizer to reduce the corrosion rate of magnesium-based materials. The obtained films were characterized by XRD, SEM, and XPS. The results showed that a Mg(OH) 2 film with nanostructure surface can be synthesized by hydrothermal method. It was observed that the thickness of film increased with the holding time. Corrosion rates of the films were studied by immersing the samples in Hank's solution (37 °C). Surface deposits of samples with films soaked in Hank's solution for 31 days were investigated by XRD, SEM, EDS, XPS, and FTIR. It verified that the corrosion rate of the magnesium alloy with grown film was slowed down in the Hank's solution and the behavior of corrosion was inhibited effectively. Amorphous calcium apatite precursor was observed to deposit on the surface of the film during corrosion experiments in Hank's solution. And the tape test revealed a strong adhesion between the film and the substrate.

  17. A Microstructure Study on an AZ31 Magnesium Alloy Tube after Hot Metal Gas Forming Process

    NASA Astrophysics Data System (ADS)

    Liu, Yi; Wu, Xin

    2007-06-01

    An AZ31 magnesium alloy tube has been deformed by the hot metal gas forming (HMGF) technique. Microstructures before and after deformation have been investigated by using Electron Backscattered Diffraction (EBSD) and Electron Microscopy. Due to the inhomogeneous distribution by induction heating, there is a temperature gradient distribution along the tube axis. Accordingly, the deformation mechanism is also different. In the middle area of deformation zone where the temperature is ˜410 °C, almost no twinning has been found, whereas at the edge areas of deformation zone where the temperature is ˜200 °C, a high density of twins has been found. EBSD experiments show a weak (0001) fiber texture along the radial direction of the tube before and after deformation in the high-temperature zone. EBSD experiments on the low temperature deformation region were not successful due to the high stored energy. Schmid factor analysis on the EBSD data shows that, despite the (0001) fiber texture, there are still many grains favoring basal slip along both the axis direction and hoop direction.

  18. Influence of chemical liquids on the fatigue crack growth of the AZ31 magnesium alloy

    NASA Astrophysics Data System (ADS)

    Wang, Zhang-Zhong; He, Xian-Cong; Bai, Yun-Qiang; Ba, Zhi-Xin; Dai, Yu-Ming; Zhou, Heng-Zhi

    2012-03-01

    The fatigue crack growth behavior of an AZ31 magnesium alloy was investigated by comparing the effect of zirconate and phosphate chemical liquids. The morphology, components, and phase compositions of the chemical depositions at the fatigue crack tip were analyzed by employing scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD), respectively. For samples with and without the chemical liquids, their stress-intensity factor values at the fatigue crack tip were compared by using a stress-strain gauge. The results demonstrated that a zirconate film (Zr x O y ˇZn x O y ) and a phosphate film (Zn3(PO4)2ˇ4H2O and MgZnP2O7) could be formed on the fatigue crack-surface at the fatigue crack tip. The stress distribution was changed because of the chemical depositions and the causticity of the chemical liquids. This could decrease the stress-intensity factor value and thus effectively cause fatigue crack closure, which reduces the fatigue crack growth rate. Moreover, it was found that the fatigue crack closure effect of zirconates was more positive than that of phosphates.

  19. 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.

  20. 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.

  1. Quantifying texture evolution during hot rolling of AZ31 Twin Roll Cast strip

    NASA Astrophysics Data System (ADS)

    Gorelova, S.; Schaeben, H.

    2015-04-01

    Multi-pass rolling experiments with an AZ31 Twin Roll Cast (TRC) alloy were performed on an industrial scaled four-high rolling mill. Within the rolling with an intermediate annealing the evolution of texture was investigated. To quantify the extent of preferred crystallographic orientation experimental X-ray pole figures were measured after different process steps and analyzed using the free and open MatlabŽ toolbox MTEX for texture analysis. The development of the fiber texture was observed and analyzed in dependence on rolling conditions. In the initial state the specimen exhibits a texture composed of a weak basal texture and a cast texture with {0001}-planes oriented across the rolling direction. During the following rolling process a fiber texture was developed. The expected strength increment of the fiber texture was quantitatively confirmed in terms of volume portions of the orientation density function around the fiber and in terms of the canonical parameters of fitted pseudo Bingham distributions. On the results of this work a model for prediction of the texture evolution during the strip rolling of magnesium in the examined parameter range was developed.

  2. 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.

  3. Smart cities of the future

    NASA Astrophysics Data System (ADS)

    Batty, M.; Axhausen, K. W.; Giannotti, F.; Pozdnoukhov, A.; Bazzani, A.; Wachowicz, M.; Ouzounis, G.; Portugali, Y.

    2012-11-01

    Here we sketch the rudiments of what constitutes a smart city which we define as a city in which ICT is merged with traditional infrastructures, coordinated and integrated using new digital technologies. We first sketch our vision defining seven goals which concern: developing a new understanding of urban problems; effective and feasible ways to coordinate urban technologies; models and methods for using urban data across spatial and temporal scales; developing new technologies for communication and dissemination; developing new forms of urban governance and organisation; defining critical problems relating to cities, transport, and energy; and identifying risk, uncertainty, and hazards in the smart city. To this, we add six research challenges: to relate the infrastructure of smart cities to their operational functioning and planning through management, control and optimisation; to explore the notion of the city as a laboratory for innovation; to provide portfolios of urban simulation which inform future designs; to develop technologies that ensure equity, fairness and realise a better quality of city life; to develop technologies that ensure informed participation and create shared knowledge for democratic city governance; and to ensure greater and more effective mobility and access to opportunities for urban populations. We begin by defining the state of the art, explaining the science of smart cities. We define six scenarios based on new cities badging themselves as smart, older cities regenerating themselves as smart, the development of science parks, tech cities, and technopoles focused on high technologies, the development of urban services using contemporary ICT, the use of ICT to develop new urban intelligence functions, and the development of online and mobile forms of participation. Seven project areas are then proposed: Integrated Databases for the Smart City, Sensing, Networking and the Impact of New Social Media, Modelling Network Performance, Mobility and Travel Behaviour, Modelling Urban Land Use, Transport and Economic Interactions, Modelling Urban Transactional Activities in Labour and Housing Markets, Decision Support as Urban Intelligence, Participatory Governance and Planning Structures for the Smart City. Finally we anticipate the paradigm shifts that will occur in this research and define a series of key demonstrators which we believe are important to progressing a science of smart cities.

  4. Salt Lake City, Utah

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The 2002 Winter Olympics are hosted by Salt Lake City at several venues within the city, in nearby cities, and within the adjacent Wasatch Mountains. This simulated natural color image presents a late spring view of north central Utah that includes all of the Olympic sites. The image extends from Ogden in the north, to Provo in the south; and includes the snow-capped Wasatch Mountains and the eastern part of the Great Salt Lake.

    This image was acquired on May 28, 2000 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER will image Earth for the next 6 years to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18,1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. Science team leader; Bjorn Eng of JPL is the project manager. ASTER is the only high resolution imaging sensor on Terra. The Terra mission is part of NASA's Earth Science Enterprise, a long-term research and technology program designed to examine Earth's land, oceans, atmosphere, ice and life as a total integrated system.

    The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping, and monitoring dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.

    Size: 63.5 x 123.3 km (38.1 x 74 miles) Location: 40.7 deg. North lat., 111.9 deg. West long. Orientation: North at top Image Data: ASTER bands 1,2, and 3. Original Data Resolution: 15 m Date Acquired: May 28, 2000

  5. Aerial view of a city

    NSDL National Science Digital Library

    Katie Hale (California State University, Fullerton; Student, Biological Sciences)

    2007-01-12

    When a city is built, habitat and most organisms living in it are killed or forced to flee. Cities use a lot of energy and water and create a tremendous amount of waste and runoff. Development is the biggest source of pollution.

  6. NEW YORK CITY NONPROFIT EXECUTIVE

    E-print Network

    Rosen, Jay

    and reporting in government contracting, especially for New York City's human services contracts, was an issue PERFORMANCE: HUMAN SERVICES EXECUTIVES EXPECT TO BE ACCOUNTABLE FOR CONTRACTS, BUT SEEK A BETTER PROCESS to human services issues, Mayor Bloomberg's plan for New York City in 2030, and government agencies' use

  7. Skewed Visions' The City Itself

    Microsoft Academic Search

    Branislav Jakovljevic

    2005-01-01

    Among proto-situationist visual works, Ansger Jorn and Guy Debord’s Fin de Copenhague (????) is distinguished by its radical approach to cartography. While in The Naked City (????) Debord takes fragments of a city map and conjoins them with arrows that indicate jumps from one area to another, in Fin de Copenhague the map almost disappears in the labyrinth of visual

  8. Dublin City University Educational Trust

    E-print Network

    Humphrys, Mark

    . It is by building these philanthropic relationships that the DCU Educational Trust assists the university building on campus has been built with the aid of funding from the Educational Trust. Over the past 19Dublin City University Educational Trust 2006 ANNUAL REPORT The Dublin City University Educational

  9. Gallup Interactives: City Wellbeing Tracking

    NSDL National Science Digital Library

    Gallup

    This tool allows the user to select a state and city and compare it on a number of measures from the Gallup Healthways Wellbeing Index to other cities of a similar size through the US.  Data can be viewed by year and the created chart can be saved.

  10. Petra: Lost City of Stone

    NSDL National Science Digital Library

    This Web site, created to complement the Petra: Lost City of Stone exhibit, looks at this once flourishing city in the heart of the ancient Near East. Although the exhibit is now closed, the web site contains a wealth of information about Petra.

  11. New York City: Musically Speaking.

    ERIC Educational Resources Information Center

    Aiex, Nola Kortner

    New York City as a subject has fascinated generations of artists, writers, and musicians. However, the glamorous image of the city has changed over the years, and in the 1960s, popular music, in particular, began to reflect a utopia/dystopia dichotomy in relation to New York. During the past twenty years, six popular singer-songwriters who have…

  12. Great Cities Institute Special Event

    E-print Network

    Illinois at Chicago, University of

    Great Cities Institute Special Event Reinventing Race, Reinventing Racism Great Cities Institute will discuss their book Reinventing Race, Reinventing Racism. They will be specifically discussing the ongoing reinvention of race and racism in the USA and its implications. From the publisher: Reinventing Race

  13. The Future of American Cities.

    ERIC Educational Resources Information Center

    Mulhern, John J., Ed.

    This document contains the proceedings of a conference dealing with the issues that face U.S. cities today. Convened in October of 1979, the conference was sponsored by the Federal Reserve Bank of Philadelphia. The document contains addresses and comments by six authorities on the current fiscal situation of large cities. The presentation…

  14. City Planning Unit: Grade 6.

    ERIC Educational Resources Information Center

    Dalton, William Edward

    Described is a project designed to make government lessons and economics more appealing to sixth-grade students by having them set up and run a model city. General preparation procedures and set-up of the project, specific lesson plans, additional activities, and project evaluation are examined. An actual 3-dimensional model city was set up on…

  15. Knowledge Infrastructures for Solar Cities

    ERIC Educational Resources Information Center

    Vanderburg, Willem H.

    2006-01-01

    The evolution of contemporary cities into solar cities will be affected by the decisions of countless specialists according to an established intellectual and professional division of labor. These specialists belong to groups responsible for advancing and applying a body of knowledge, and jointly, these bodies of knowledge make up a knowledge…

  16. Smart Cities and Sustainability Models

    Microsoft Academic Search

    Lorena BATAGAN

    2011-01-01

    In our age cities are complex systems and we can say systems of systems. Today locality is the result of using information and communication technologies in all departments of our life, but in future all cities must to use smart systems for improve quality of life and on the other hand for sustainable development. The smart systems make daily activities

  17. READY4SmartCities ICT Roadmap and Data Interoperability for Energy Systems in Smart Cities

    E-print Network

    Paris-Sud XI, Université de

    READY4SmartCities ­ ICT Roadmap and Data Interoperability for Energy Systems in Smart Cities and Data Interoperability for Energy Systems in Smart Cities Project Acronym: READY4SmartCities Grant of the Ready4SmartCities project is to support energy data interoperability in the context of SmartCities

  18. Shaping Livable Cities

    NSDL National Science Digital Library

    Taboulchanas, Kristina

    2006-01-01

    Thinking about policy solutions for urban regions is a great deal easier than actually putting them into action, and that is why this latest report from The International Development Research Centre in Canada is most welcome. This recently released 36-page report starts off with this important sentence: "They [cities] are engines of economic growth and cultural prosperity, but they are also centres of pollution and poverty." Divided into three substantive chapters, the report provides specific case studies of various urban innovations, such as Beijing's urban agriculture initiatives and a program designed to integrate agriculture into municipal planning in Kampala, Uganda. Other studies draw on experiences in Vancouver, Hyderabad, and Managua. Overall, the report is well written and may be of great interest to persons in the fields of international development as well as scholars interested in evaluating such programs.

  19. Kansas City Hopewell

    NSDL National Science Digital Library

    In 2003, the University of Kansas Museum of Anthropology was awarded a Digital Library Initiatives grant for a project that would result in this rather useful and interesting digitization project. The hope was that the museum would be able to digitize some of the excellent collection of material recovered from the 30 Kansas City Hopewell archaeological sites that are located around the junction of the Kansas and Missouri Rivers. Most of the sites date to the Middle Woodland or Early Ceramic period, which ranges from 100 B.C. to 700 A.D. One of the fine features of this site is the 3D images area, which includes 32 excavated items that visitors may view in their entirety. The site is rounded out by a selection of helpful suggested readings and a collection of external links to sites such as those of the Society for American Archaeology and ArchNet.

  20. Healthy Cities: a guide to the literature.

    PubMed Central

    Kenzer, M

    2000-01-01

    The author reviews the literature on attempts by city governments, international agencies, and nongovernmental and community organizations to improve city life around the world through Healthy Cities projects. PMID:10968770

  1. Gateway Antarctica's Christchurch City Council Antarctic Scholarship

    E-print Network

    Hickman, Mark

    Gateway Antarctica's Christchurch City Council Antarctic Scholarship The Christchurch City Council by Antarctica New Zealand. 1. The Scholarship will be known as the Christchurch City Council Antarctic Scholarship and administered by Gateway Antarctica, the Centre for Antarctic Studies and Research

  2. 2006 Match Results Institution Specialty City ST

    E-print Network

    Leistikow, Bruce N.

    CA Cleveland Clinic Fdn-OH Anesthesiology CLEVELAND OH U Arizona Affil Hosps Emergency Medicine TUCSON AZ UC San Francisco-Fresno-CA Emergency Medicine FRESNO CA Loma Linda University-CA Emergency Medicine LOMA LINDA CA Loma Linda University-CA Emergency Medicine LOMA LINDA CA Loma Linda University

  3. Plastic Deformation Characteristics Of AZ31 Magnesium Alloy Sheets At Elevated Temperature

    SciTech Connect

    Park, Jingee; Lee, Jongshin [Graduate School, Kyungpook National University, Deagu 702-701 (Korea, Republic of); You, Bongsun [Department of Materials Technology, Korea Institute of Machinery and Materials, Changwon 641-831 (Korea, Republic of); Choi, Seogou [Digital Production Processing and Forming Team, Korea Institute of Industrial Technology, Incheon 406-800 (Korea, Republic of); Kim, Youngsuk [Department of Mechanical Engineering, Kyoungpook National University, Deagu 702-701 (Korea, Republic of)

    2007-05-17

    Using lightweight materials is the emerging need in order to reduce the vehicle's energy consumption and pollutant emissions. Being a lightweight material, magnesium alloys are increasingly employed in the fabrication of automotive and electronic parts. Presently, magnesium alloys used in automotive and electronic parts are mainly processed by die casting. The die casting technology allows the manufacturing of parts with complex geometry. However, the mechanical properties of these parts often do not meet the requirements concerning the mechanical properties (e.g. endurance strength and ductility). A promising alternative can be forming process. The parts manufactured by forming could have fine-grained structure without porosity and improved mechanical properties such as endurance strength and ductility. Because magnesium alloy has low formability resulted form its small slip system at room temperature it is usually formed at elevated temperature. Due to a rapid increase of usage of magnesium sheets in automotive and electronic industry it is necessary to assure database for sheet metal formability and plastic yielding properties in order to optimize its usage. Especially, plastic yielding criterion is a critical property to predict plastic deformation of sheet metal parts in optimizing process using CAE simulation. Von-Mises yield criterion generally well predicts plastic deformation of steel sheets and Hill'1979 yield criterion predicts plastic deformation of aluminum sheets. In this study, using biaxial tensile test machine yield loci of AZ31 magnesium alloy sheet were obtained at elevated temperature. The yield loci ensured experimentally were compared with the theoretical predictions based on the Von-Mises, Hill, Logan-Hosford, and Barlat model.

  4. Nano-hydroxyapatite reinforced AZ31 magnesium alloy by friction stir processing: a solid state processing for biodegradable metal matrix composites.

    PubMed

    Ratna Sunil, B; Sampath Kumar, T S; Chakkingal, Uday; Nandakumar, V; Doble, Mukesh

    2014-04-01

    Friction stir processing (FSP) was successfully adopted to fabricate nano-hydroxyapatite (nHA) reinforced AZ31 magnesium alloy composite as well as to achieve fine grain structure. The combined effect of grain refinement and the presence of embedded nHA particles on enhancing the biomineralization and controlling the degradation of magnesium were studied. Grain refinement from 56 to ~4 and 2 ?m was observed at the stir zones of FSP AZ31 and AZ31-nHA composite respectively. The immersion studies in super saturated simulated body fluid (SBF 5×) for 24 h suggest that the increased wettability due to fine grain structure and nHA particles present in the AZ31-nHA composite initiated heterogeneous nucleation which favored the early nucleation and growth of calcium-phosphate mineral phase. The nHA particles as nucleation sites initiated rapid biomineralization in the composite. After 72 h of immersion the degradation due to localized pitting was observed to be reduced by enhanced biomineralization in both the FSPed AZ31 and the composite. Also, best corrosion behavior was observed for the composite before and after immersion test. MTT assay using rat skeletal muscle (L6) cells showed negligible toxicity for all the processed and unprocessed samples. However, cell adhesion was observed to be more on the composite due to the small grain size and incorporated nHA. PMID:24375146

  5. Wear and corrosion resistance of AZ31 magnesium alloy irradiated by high-intensity pulsed ion beam

    NASA Astrophysics Data System (ADS)

    Li, P.; Han, X. G.; Xin, J. P.; Zhu, X. P.; Lei, M. K.

    2008-09-01

    The wear and corrosion resistance of AZ31 magnesium alloy irradiated by high-intensity pulsed ion beam (HIPIB) at an ion current density of 100-300 A/cm 2 with shot number of 1-10 are investigated by sliding wear test and potentiodynamic polarization measurement. The surface and cross-sectional morphologies, phase structure and surface microhardness of the irradiated AZ31 magnesium alloy samples are characterized by scanning electron microscopy (SEM), optical microscopy, X-ray diffraction (XRD) and Vickers tester, respectively. The HIPIB irradiation produces the hardened surface layers and improves abrasive wear resistance of all the samples. The wear volume of the irradiated samples at 200 A/cm 2 and 300 A/cm 2 with 10 shots as well as 100 A/cm 2 with 5 shots is about four times less than that of the original sample. The apparent increase in corrosion resistance is achieved for all the irradiated samples in 0.01 mol/l NaCl solution with a pH value of 12. The corrosion potential and pitting breakdown potential for the samples irradiated at 100 A/cm 2 with 5 shots are 560 and 630 mV higher than those of the original sample, -1560 mV and -1300 mV (SCE), respectively. It is found that the combined improvement in wear and corrosion resistance of AZ31 magnesium alloy is achieved by HIPIB irradiation, which is ascribed to the microstructural refinement and the chemical homogeneity of the irradiated magnesium alloy.

  6. The Ancient City of Petra

    NSDL National Science Digital Library

    This fun Web article is part of OLogy, where kids can collect virtual trading cards and create projects with them. Here, they learn about the ancient city of Petra. The article begins with an overview of this city, which was located along the ancient trade routes between Arabia, Egypt, and the Mediterranean Sea. Kids then have the chance to take a walk through Petra's ruins. This clickable illustration has 11 places for them to explore. The article concludes with an extensive information section on the history of the city.

  7. New York City in 2050

    NSDL National Science Digital Library

    This 47 minute radio broadcast speculates what New York City might be like in the year 2050, after a century of human-induced climate change. What could a warming planet mean for this city and its people? Plus, can taking action towards sustainable design - from green office buildings to living roofs - ensure a better future for the Big Apple? The show discusses how city planners and scientists use climate models to project possible futures and how regional choices are being made to cope with greenhouse warming.

  8. A tale of two machines: a review of the BLAST meeting, Tucson, AZ, 20-24 January 2013.

    PubMed

    Josenhans, Christine; Jung, Kirsten; Rao, Christopher V; Wolfe, Alan J

    2014-01-01

    Since its inception, Bacterial Locomotion and Signal Transduction (BLAST) meetings have been the place to exchange and share the latest developments in the field of bacterial signal transduction and motility. At the 12th BLAST meeting, held last January in Tucson, AZ, researchers from all over the world met to report and discuss progress in diverse aspects of the field. The majority of these advances, however, came at the level of atomic level structures and their associated mechanisms. This was especially true of the biological machines that sense and respond to environmental changes. PMID:24125587

  9. Comparative study on characteristics of hybrid laser-TIG welded AZ61\\/Q235 lap joints with and without interlayers

    Microsoft Academic Search

    Xiao-Dong Qi; Li-Ming Liu

    2010-01-01

    AZ61 Mg alloy to Q235 mild steel were lap joined using hybrid laser-TIG welding technique. At the joint interface and fusion\\u000a zone (FZ), microstructure was revealed by scanning electron microscopy equipped with energy dispersive X-ray spectroscopy;\\u000a element distribution was analyzed by electron probe micro-analyzer; intermediate phases were identified using X-ray diffraction\\u000a test. Comparing with interlayer-free joints, the new intermediate phases

  10. The mechanical properties and microstructures of AZ91D magnesium alloy processed by selective laser cladding with Al powder

    NASA Astrophysics Data System (ADS)

    Lin, Pengyu; Zhang, Zhihui; Ren, Luquan

    2014-08-01

    This work focuses on the effects of selective laser cladding using Al powder on the properties and microstructure of Mg alloy AZ91D, with different experimental parameters. The scanning strategy was inspired by the alternately hard-soft shell surface structures. The microstructure was greatly refined. Furthermore, the growth of the ?-Mg17Al12 dendrite was curbed. The treatment depth is ~900 ?m. The UTS, YS and microhardness were notably increased. However, the ductility was decreased by a part. The output power of 2200 W and the scanning speed of 180 mm/min are the optimum combination. The resulting wear resistance was thus the highest of all.

  11. A Tale of Two Machines: A review of the BLAST meeting, Tucson, AZ, January 20–24, 2013

    PubMed Central

    Josenhans, Christine; Jung, Kirsten; Rao, Christopher V.; Wolfe, Alan J.

    2013-01-01

    Since its inception, Bacterial Locomotion and Signal Transduction (BLAST) meetings have been the place to exchange and share the latest developments in the field of bacterial signal transduction and motility. At the 12th BLAST meeting, held last January in Tucson AZ, researchers from all over the world met to report and discuss progress in diverse aspects of the field. The majority of these advances, however, came at the level of atomic level structures and their associated mechanisms. This was especially true of the biological machines that sense and respond to environmental changes. PMID:24125587

  12. SUICIDE IN JHANSI CITY

    PubMed Central

    Shukla, G.D.; Verma, B.L.; Mishra, D.N.

    1990-01-01

    SUMMARY The 187 suicide occurring in the city of Jhansi, over a period of two years (1986-87), gave an annual incidence rate of 29 per lakh population. The rate was higher for females (34 per lakh) than for males (24 per lakh). The commonest age group was the third decade (51.3%), followed by the second (28.4%); the average age of males being significantly higher. The married committed suicide more often. Domestic strife (38.3%) and mental illness (23.5%) were the common cause while no causative factor could be discerned in 38.5% of the cases. The two sexes differed significantly with respect to burning and getting run over by train as the preferred method of suicide. Burning was largely a female preserve while getting run over by train was used almost exclusively by males. Poisoning and hanging were used slightly more often by males while drowning was used a bit more frequently by females. PMID:21927426

  13. City profile: Almaty, Kazakhstan.

    PubMed

    Djusubalieva, T; Umurzina, G B

    1995-05-01

    Medical services have reported significant social distress in and around Almaty, the capital of Kazakhstan. A generally unhealthy female population relies upon abortion for contraception, with each women having an average of five abortions over the course of her reproductive lifetime. Many of these women have gynecological problems, the level of infertility is on the rise, and 70% of all registered pregnant women have some kind of disease. Anemia is most frequently observed, increasing four-fold over the last four years. Diseases of the urogenital system have doubled over the same period, while the number of premature deliveries grows annually, currently 8% of all deliveries. The City Health Care Department has declared a state of emergency for gynecological and obstetrical services. Order 33 of February 12, 1994, however, approved the Family Planning Program requiring all medical institutions to provide family planning services with the goal of reducing the number of abortions by 50%, thereby decreasing the levels of maternal and perinatal mortality. The program covered the integration of obstetrical and gynecological services with medical services to boost cohesion and access to both patients and services. It also defined the duties of obstetricians, gynecologists, general practitioners, pediatricians, and other medical experts. The authors describe the program's structure. PMID:12222257

  14. Mapping mayhem in the city

    E-print Network

    Bates, Ellie

    2008-01-01

    Mapping mayhem in the city? Exploring the space time dynamics of criminal damage and alcohol with Geovisualisation and ESDA. This research examines if the combination of criminal damage and alcohol leads to mayhem ...

  15. Layout of Ancient Maya Cities

    NASA Astrophysics Data System (ADS)

    Aylesworth, Grant R.

    Although there is little doubt that the ancient Maya of Mesoamerica laid their cities out based, in part, on astronomical considerations, the proliferation of "cosmograms" in contemporary scholarly discourse has complicated matters for the acceptance of rigorous archaeoastronomical research.

  16. The self-aware city

    E-print Network

    Sevtsuk, Andres

    2006-01-01

    This thesis explores the idea of real-time urban space management. While increasing amounts of real-time information about the city, specifically the location of people and resources, appear, it becomes necessary to explore ...

  17. A Protein Complex Containing the Conserved Swi2/Snf2-Related ATPase Swr1p Deposits Histone Variant H2A.Z into Euchromatin

    PubMed Central

    2004-01-01

    The conserved histone variant H2A.Z functions in euchromatin to antagonize the spread of heterochromatin. The mechanism by which histone H2A is replaced by H2A.Z in the nucleosome is unknown. We identified a complex containing 13 different polypeptides associated with a soluble pool of H2A.Z in Saccharomyces cerevisiae. This complex was designated SWR1-Com in reference to the Swr1p subunit, a Swi2/Snf2-paralog. Swr1p and six other subunits were found only in SWR1-Com, whereas six other subunits were also found in the NuA4 histone acetyltransferase and/or the Ino80 chromatin remodeling complex. H2A.Z and SWR1 were essential for viability of cells lacking the EAF1 component of NuA4, pointing to a close functional connection between these two complexes. Strikingly, chromatin immunoprecipitation analysis of cells lacking Swr1p, the presumed ATPase of the complex, revealed a profound defect in the deposition of H2A.Z at euchromatic regions that flank the silent mating type cassette HMR and at 12 other chromosomal sites tested. Consistent with a specialized role for Swr1p in H2A.Z deposition, the majority of the genome-wide transcriptional defects seen in swr1? cells were also found in htz1? cells. These studies revealed a novel role for a member of the ATP-dependent chromatin remodeling enzyme family in determining the region-specific histone subunit composition of chromatin in vivo and controlling the epigenetic state of chromatin. Metazoan orthologs of Swr1p (Drosophila Domino; human SRCAP and p400) may have analogous functions. PMID:15045029

  18. A protein complex containing the conserved Swi2/Snf2-related ATPase Swr1p deposits histone variant H2A.Z into euchromatin.

    PubMed

    Kobor, Michael S; Venkatasubrahmanyam, Shivkumar; Meneghini, Marc D; Gin, Jennifer W; Jennings, Jennifer L; Link, Andrew J; Madhani, Hiten D; Rine, Jasper

    2004-05-01

    The conserved histone variant H2A.Z functions in euchromatin to antagonize the spread of heterochromatin. The mechanism by which histone H2A is replaced by H2A.Z in the nucleosome is unknown. We identified a complex containing 13 different polypeptides associated with a soluble pool of H2A.Z in Saccharomyces cerevisiae. This complex was designated SWR1-Com in reference to the Swr1p subunit, a Swi2/Snf2-paralog. Swr1p and six other subunits were found only in SWR1-Com, whereas six other subunits were also found in the NuA4 histone acetyltransferase and/or the Ino80 chromatin remodeling complex. H2A.Z and SWR1 were essential for viability of cells lacking the EAF1 component of NuA4, pointing to a close functional connection between these two complexes. Strikingly, chromatin immunoprecipitation analysis of cells lacking Swr1p, the presumed ATPase of the complex, revealed a profound defect in the deposition of H2A.Z at euchromatic regions that flank the silent mating type cassette HMR and at 12 other chromosomal sites tested. Consistent with a specialized role for Swr1p in H2A.Z deposition, the majority of the genome-wide transcriptional defects seen in swr1Delta cells were also found in htz1Delta cells. These studies revealed a novel role for a member of the ATP-dependent chromatin remodeling enzyme family in determining the region-specific histone subunit composition of chromatin in vivo and controlling the epigenetic state of chromatin. Metazoan orthologs of Swr1p (Drosophila Domino; human SRCAP and p400) may have analogous functions. PMID:15045029

  19. Metroscope - Web sites by city

    NSDL National Science Digital Library

    Metroscope is a directory of resources arranged by metropolitan area. It contains over four thousand sites. Subject category breakdown under each site includes arts and entertainment, business, media, sports, and professional services. The directory is searchable by subject and across cities. A fast and powerful way to access the Internet resources of over 40 U.S. and five international cities, with new sites being added weekly. The site is provided by the Isotropic Media Group.

  20. Deer Tracks in the City?

    ERIC Educational Resources Information Center

    Quigley, Cassie Fay; Beeman-Cadwallader, Nicole; Riggs, Morgan; Rodriguez, Antonia; Buck, Gayle

    2009-01-01

    "Why would a deer print be in the city?" wondered a student. She had noticed the track near a grocery store that morning with her mother. She was familiar with deer and had noticed their prints on a trip to a local museum; however, she had never seen a deer in the city before this experience. As she retold the story to her classmates, her question…

  1. Automobile emissions in Mexico City

    SciTech Connect

    Beaton, S.; Bishop, G.; Stedman, D.

    1996-09-01

    In order to determine the exhaust characteristics of the Mexico City vehicle fleet, a Fuel Efficiency Automotive Test (FEAT) unit was placed at 5 different sites over a 10 day period from 11 February 1991 through 21 February 1991. Valid data for the percent of carbon Monoxide (CO), hydrocarbons (HC), and carbon dioxide (CO{sub 2}) were obtained on 31 838 vehicles. This represents approximately 1 % of the entire Mexico City fleet.

  2. Industry and the smart city

    Microsoft Academic Search

    Zelda Bronstein

    2009-01-01

    These days, U.S. city planning exudes an audacious air. The suburban sprawl that has dominated U.S. development since the Second World War is under assault from a multitude of policy makers and activists bent on protecting the environment and revitalizing city life. Rallying to varied watchwords—smart growth, new urbanism, sustainable development, green development, livable communities, traditional neighborhood development—the insurgent urbanists

  3. Network Structure and City Size

    PubMed Central

    Levinson, David

    2012-01-01

    Network structure varies across cities. This variation may yield important knowledge about how the internal structure of the city affects its performance. This paper systematically compares a set of surface transportation network structure variables (connectivity, hierarchy, circuity, treeness, entropy, accessibility) across the 50 largest metropolitan areas in the United States. A set of scaling parameters are discovered to show how network size and structure vary with city size. These results suggest that larger cities are physically more inter-connected. Hypotheses are presented as to why this might obtain. This paper then consistently measures and ranks access to jobs across 50 US metropolitan areas. It uses that accessibility measure, along with network structure variables and city size to help explain journey-to-work time and auto mode share in those cities. A 1 percent increase in accessibility reduces average metropolitan commute times by about 90 seconds each way. A 1 percent increase in network connectivity reduces commute time by 0.1 percent. A 1 percent increase in accessibility results in a 0.0575 percent drop in auto mode share, while a 1 percent increase in treeness reduces auto mode share by 0.061 percent. Use of accessibility and network structure measures is important for planning and evaluating the performance of network investments and land use changes. PMID:22253764

  4. How To Save Our Shrinking Cities.

    ERIC Educational Resources Information Center

    Rybcznski, Witold; Linneman, Peter D.

    1999-01-01

    Explores solutions to the problem of shrinking cities, population declines in urban areas. Consolidation and de-annexation are not desirable alternatives, but for many shrinking cities no other workable alternative can be seen. The reality is that many cities will continue to shrink. Radical redesign can make cities better and smaller. (SLD)

  5. THE SMART CITY INFRASTRUCTURE DEVELOPMENT & MONITORING

    Microsoft Academic Search

    Mahmoud AL-HADER; Ahmad RODZI

    2009-01-01

    The smart city infrastructure is the introductory step for establishing the overall smart city framework and architecture. Very few smart cities are recently established across the world. Some examples are: Dubai, Malta, Kochi (India), Singapore. The scope of these cities is mainly limited to construct a technology park converting the industrial real estate to state of the art information technology

  6. Alt-Az telescope control system standardization attempt: case study of the TT1 (Toppo Telescope #1) control system

    NASA Astrophysics Data System (ADS)

    Mancini, Dario; Brescia, Massimo; Spirito, Gianfranco

    1998-05-01

    The TT1 is a 1.54 m Alt-Az telescope designed and built by the Technology Working Group of the Astronomical Observatory of Capodimonte, Naples, Italy. The standardization process is of course one of the fundamental requirements for telescope control system design and development, well considered in the TT1 design. In this paper we present the approach used to identify a control system applicable to medium-size Alt-Az telescope. The TT1 control system architecture is based on a distributed working flow and it is PC-based, i.e. organized in several interconnected standard PCs and standard fast communication protocol. Every PC is based on the 'dedicated processing unit' concept and it makes real time own tasks independently by other units. Also, the extremely reduced communication flow between PCs, and the internal organization based on the preference given to software rather than hardware solutions, makes its control system extremely reliable, easily reconfigurable and upgradable, obsolescence deprived and independent from any hardware choice.

  7. Conserved histone variant H2A.Z protects euchromatin from the ectopic spread of silent heterochromatin.

    PubMed

    Meneghini, Marc D; Wu, Michelle; Madhani, Hiten D

    2003-03-01

    Boundary elements hinder the spread of heterochromatin, yet these sites do not fully account for the preservation of adjacent euchromatin. Histone variant H2A.Z (Htz1 in yeast) replaces conventional H2A in many nucleosomes. Microarray analysis revealed that HTZ1-activated genes cluster near telomeres. The reduced expression of most of these genes in htz1Delta cells was reversed by the deletion of SIR2 (sir2Delta) suggesting that H2A.Z antagonizes telomeric silencing. Other Htz1-activated genes flank the silent HMR mating-type locus. Their requirement for Htz1 can be bypassed by sir2Delta or by a deletion encompassing the silencing nucleation sites in HMR. In htz1Delta cells, Sir2 and Sir3 spread into flanking euchromatic regions, producing changes in histone H4 acetylation and H3 4-methylation indicative of ectopic heterochromatin formation. Htz1 is enriched in these euchromatic regions and acts synergistically with a boundary element to prevent the spread of heterochromatin. Thus, euchromatin and heterochromatin each contains components that antagonize switching to the opposite chromatin state. PMID:12628191

  8. A New Constitutive Model for AZ31B Magnesium Alloy Sheet Deformed at Elevated Temperatures and Various Strain Rates

    NASA Astrophysics Data System (ADS)

    Nguyen, Duc-Toan

    2014-12-01

    In this study, a new constitutive model is established for AZ31B magnesium alloy sheet at elevated temperatures and strain rates in order to describe two competing mechanisms for deformation, i.e. both work-hardening and softening stage of AZ31B magnesium alloy sheet. Stress-strain curves obtained by conducting uni-axial tensile tests at elevated and strain rates were first separated at the maximum stress and corresponding strain values. Voce's law [25] was then employed to fit separated hardening and softening stage. A MATLAB tool is used to determine material parameters by using least square fitting method at various temperatures and strain rate. The mergence of separated work-hardening and softening equations is in good agreement with experimental data. The parameters of fitting curves are utilized to determine them as a function of temperature and strain rate using a surface fitting method. The final equation is then implemented to predict stress-strain curves at various temperatures and strain rates. The proposed equation showed the good comparability between the simulation results and the corresponding experiments.

  9. Numerical Assessment of the Role of Slip and Twinning in Magnesium Alloy AZ31B During Loading Path Reversal

    NASA Astrophysics Data System (ADS)

    Wang, Huamiao; Wu, Peidong; Wang, Jian

    2015-07-01

    Magnesium alloy AZ31B plastically deforms via twinning and slip. Corresponding to the unidirectional nature of twinning, the activity of twinning/detwinning is directly related to loading history and materials texture. Using the elastic viscoplastic self-consistent model implementing with the twinning and detwinning model (EVPSC-TDT), we revisited experimental data of AZ31B sheets under four different strain paths: (1) tension-compression-tension along rolling direction, (2) tension-compression-tension along transverse direction, (3) compression-tension-compression along rolling direction, and (4) compression-tension-compression along transverse direction, and identified the dominant deformation mechanisms with respect to the strain path. We captured plastic deformation behaviors observed in experiments and quantitatively interpreted experimental observations in terms of the activities of different deformation mechanisms and the evolution of texture. It is found that the in-plane pre-tension has slight effect on the subsequent deformation, and the pre-compression and the reverse tension after compression have significant effect on the subsequent deformation. The inelastic behavior under compressive unloading is found to be insignificant at a small strain level but pronounced at a large strain level. Such significant effect is mainly ascribed to the activity of twinning and detwinning.

  10. Study of deformation texture in an AZ31 magnesium alloy rolled at wide range of rolling speed and reductions

    NASA Astrophysics Data System (ADS)

    Sanjari, M.; Tamimi, S.; Su, J.; Kabir, A. S.; Hara, K.; Utsunomiya, H.; Petrov, R.; Yue, S.; Kestens, L.

    2015-04-01

    The plasticity of Mg is restricted at low temperatures because: (a) only a small number of deformation mechanisms can be activated, and (b) a preferred crystallographic orientation (texture) develops in wrought alloys, especially in flat-rolled sheets. This causes problems in thin sheet processing as well as component manufacturing from the sheet. In this study, different rolling speeds from 15 to 1000 m/min were employed to warm-roll AZ31B magnesium alloy to different reductions. The results show that AZ31B sheets rolled at 15 m/min and 100 °C has fractured for reductions of more than 30% per pass. However, by increasing the rolling speed to 1000 m/min the rollability was improved significantly and the material can be rolled to reductions of more than 70% per pass. The results show that with increasing strain rate at 100°C, the splitting of basal poles was observed, indicating the activation of more contraction twins and secondary twins.

  11. Preparation and corrosion resistance of electroless Ni-P/SiC functionally gradient coatings on AZ91D magnesium alloy

    NASA Astrophysics Data System (ADS)

    Wang, Hui-Long; Liu, Ling-Yun; Dou, Yong; Zhang, Wen-Zhu; Jiang, Wen-Feng

    2013-12-01

    In this paper, the protective electroless Ni-P/SiC gradient coatings on AZ91D magnesium alloy substrate were successfully prepared. The prepared Ni-P/SiC gradient coatings were characterized for its microstructure, morphology, microhardness and adhesion to the substrate. The deposition reaction kinetics was investigated and an empirical rate equation for electroless Ni-P/SiC plating on AZ91D magnesium alloy was developed. The anticorrosion properties of the Ni-P/SiC gradient coatings in 3.5 wt.% NaCl solution were evaluated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) studies. The potentiodynamic polarization measurements revealed that the SiC concentration in the bath and heat treatment can influence the corrosion protection performance of electroless deposited Ni-P/SiC gradient coatings. EIS studies indicated that higher charge transfer resistance and slightly lower capacitance values were obtained for Ni-P/SiC gradient coatings compared to Ni-P coatings. The corrosion resistance of the Ni-P/SiC gradient coatings increases initially and decreases afterwards with the sustained increasing of immersion time in the aggressive medium. The electroless Ni-P/SiC gradient coatings can afford better corrosion protection for magnesium alloy substrate compared with Ni-P coatings.

  12. Iron Phosphate Glass for Vitrifying Hanford AZ102 LAW in Joule Heated and Cold Crucible Induction Melters - 12240

    SciTech Connect

    Day, Delbert E.; Brow, Richard K.; Ray, Chandra S.; Reis, Signo T. [Missouri University of Science and Technology, 1870 Miner Circle, Rolla, MO 65409 (United States); Kim, Cheol-Woon [MO-SCI Corporation, 4040 HyPoint North, Rolla, MO 65401 (United States); Vienna, John D.; Sevigny, Gary [Pacific North West National Laboratory, Battelle Blvd., Richland, WA 99352 (United States); Peeler, David; Johnson, Fabienne C.; Hansen, Eric K. [Savannah River National Laboratory, Savannah River Site, 999-W, Aiken, SC 29803 (United States); Soelberg, Nick [Idaho National Laboratory, 2525 Fremont Avenue, Idaho Falls, ID 83415 (United States); Pegg, Ian L.; Gan, Hao [Catholic University of America, 620 Michigan Avenue, N.E., Washington, DC 20064 (United States)

    2012-07-01

    An iron phosphate composition for vitrifying a high sulfate (?17 wt%) and high alkali (?80 wt%) Hanford low activity waste (LAW), known as AZ-102 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 AZ-102 which corresponded to a total alkali and sulfate (represented as SO{sub 3}) content of 21 and 4.4 wt%, respectively. A slurry (7 M Na{sup +}) of MS26AZ102F-2 simulant was melted continuously at temperatures between 1030 and 1090 deg. C for 10 days in a small JHM at PNNL and for 70 hours in a CCIM at INL. The as-cast glasses produced in both melters and in trial laboratory experiments along with their canister centerline cooled (CCC) counterparts met the requirements for the Product Consistency Test (PCT) and the Vapor Hydration Test (VHT) responses in the Hanford Tank Waste Treatment and Immobilization Plant (WTP) Contract. These glass waste forms retained up to 77 % of the SO{sub 3} (3.3 wt%), 100% of the Cesium, and 33 to 44% of the rhenium (used as a surrogate for Tc) 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 was melted continuously in a slurry fed JHM and in the US, thereby, demonstrating that iron phosphate glasses can be used as alternative hosts for vitrifying nuclear waste. The following conclusions are drawn from the results of the present work. (1) An iron phosphate composition, designated as MS26AZ102F-2, containing 26 wt% of the simulated high sulfate (17 wt%), high alkali (80 wt%) Hanford AZ-102 LAW meets all the criteria for processing in a JHM and CCIM. This composition produces a homogeneous glass with a density of 2.80 ą 0.04 g/cm{sup 3} after melting between 1000 and 1050 deg. C for 3 to 5 h. (2) This is the first time that an iron phosphate glass was melted in the JHM continuously for 10 days achieving a specific melting rate of 1010 kg/m2/day and in the CCIM for 70 hrs with a melting rate of 664 kg/m{sup 2}/day. (3) The analyzed (ICP-AES) compositions for all the glasses prepared under several melting conditions are in excellent agreement with the target composition. The variation of melting conditions include: (i) use of small scale/short melting time to large scale/long melting time (300 g to 80 kg, 4 h to 10 days) operations including melting in the JHM and CCIM, (ii) use of dry or wet (slurry) melter feed, (iii) addition of reductant (sugar) in the batch, and (iv) bubbling the melt with air. (4) The chemical durability as measured by PCT and VHT for the quenched and CCC-treated waste forms prepared from laboratory, JHM or CCIM melting exceeds the DOE requirements for LAW. (5) Depending upon the melting time (4 h to 10 days), the average concentration of SO{sub 3} in the MS26AZ102F-2 iron phosphate glass waste form varies from about 1.78 (RSM) to 3.74 (laboratory melt) wt% which corresponds to an SO{sub 3} retention of 41 to 86% when melted between 1030 at 1050 deg. C in air. (6) The retention of SO{sub 3} in the glass was reduced when a reductant (sugar) was added to the slurry. (7) The retention of other problem components like Cesium and Rhenium/Tc-99 is also high; from 92 to 100% for Cs{sub 2}O under different melting conditions, and from 66 to 33% for Re{sub 2}O{sub 7} for melts processed from 3 to 5 hours and up to 10 days. (8) Corrosion tests on Inconel 693 and K-3 refractory at temperatures between 1000 and 1050 deg. C indicate that both materials should be suitable for melting iron phosphate glasses. (9) The viscosity and electrical conductivity of the MS26AZ102F-2 melt are within the acceptable limits for RSM and CCIM processing. (10)This work has shown that iron phosphate compositions are a pot

  13. Creating a "city of art" : evaluating Singapore's vision of becoming a renaissance city

    E-print Network

    Lee, Wai Kin, 1975-

    2003-01-01

    The arts have been used by many cities as a way to regenerate their urban environments and rejuvenate their economies. In this thesis, I examine an approach in which city-wide efforts are undertaken to create a "city of ...

  14. Kinetic City - Mission to Vearth

    NSDL National Science Digital Library

    American Association for the Advancement of Science (AAAS; )

    2005-01-01

    "Kinetic City" 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.

  15. Shenzhen: city of suspended possibility.

    PubMed

    Bach, Jonathan

    2011-01-01

    This essay on Shenzhen, China, presents three vignettes addressing the question of home in a city of migrants. The first section explores the ubiquitous narratives of success forming the city's foundational myth. The second follows this myth into the world of a Shenzhen filmmaker and his characters, as they navigate the tension between the idea of home and the urge to start anew, resulting in the suspended possibility of the title. The last section looks at young architects who hope to preserve the city's heterotopic sites of migrants and original villagers through architectural innovations. The cases show how an economy of desire supplements the political economy of this export-driven city. The city appears as an urban desiring machine that produces itself as an object of desire for the migrants of all classes who flock to its factories, "urban villages", white-collar jobs, luxury villas and underground economy. The essay is an encounter with the mythology of success and failure, the intertwining of home as an end and home as the beginning, and with the manipulation of space that allows residents to control their own subjectivity. PMID:21319435

  16. Epigenetic regulation of the ribosomal cistron seasonally modulates enrichment of H2A.Z and H2A.Zub in response to different environmental inputs in carp (Cyprinus carpio)

    PubMed Central

    2013-01-01

    Background The specific deposition of histone variants into chromatin is an important epigenetic mechanism that contributes to gene regulation through chromatin architectural changes. The histone variant H2A.Z is essential in higher eukaryotes, and its incorporation within chromatin is a relevant process for gene expression and genome stability. However, the dual positive and negative roles of H2A.Z in gene regulation still remain unclear. We previously reported that acclimatization in common carp fish (Cyprinus carpio) involves cyclical seasonal gene reprogramming as an adaptation response to its natural environment, when rRNA synthesis and processing are profoundly affected. Epigenetic mechanisms primarily contribute to the transcriptional modulation of ribosomal genes concomitant with the acclimatization process, thus significantly regulating this process. The aim of this study was to describe the presence of several H2A.Z subtypes in carp, and assess the role of H2A.Z on the ribosomal cistron in summer- and winter-acclimatized carp. Results This paper reports for the first time about the transcriptional expression of four different H2A.Z subtypes belonging to the same organism. Remarkably, a novel H2A.Z.7 was found, which corresponds to a tissue-specific histone subtype that contains seven amino acid residues longer than the canonical H2A.Z. Moreover, H2A.Z enrichment through the ribosomal cistron was significantly higher during summer, when rRNA transcription and processing are highly active, than it was in winter. Similar patterns of H2A.Z enrichment are found in two seasonally active promoters for genes transcribed by RNA polymerase II, the L41 and ?9-desaturase genes. Interestingly, ubiquitylated-H2A.Z (H2A.Zub) was strongly enriched on regulatory regions of the ribosomal cistron in summer-acclimatized carp. Additionally, H2A.Z was present in both heterochromatin and euchromatin states on ribosomal cistron and RNA polymerase II promoters. Conclusions Our study revealed seasonally-dependent H2A.Z enrichment for active ribosomal cistron and RNA polymerase II promoters during the carp environmental adaptation. Moreover, seasonal H2A.Zub enrichment appears as a specific mechanism contributing to the regulation of chromatin architecture under natural conditions. The existence of several H2A.Z subtypes in carp suggests that the epigenetic regulation in this species constitutes a complex and finely tuned mechanism developed to cope with seasonal environmental changes that occur in its habitat. PMID:23866978

  17. Bourses et prix de 1er cycle Rpertoires | Facults | Bibliothques | Plan campus | Sites A-Z | Mon portail UdeM

    E-print Network

    Parrott, Lael

    Bourses et prix de 1er cycle Répertoires | Facultés | Bibliothčques | Plan campus | Sites A-Z | Mon le montant) Sélectionner 0 0 #12;Bourses et prix de 1er cycle Pręt Bourse $ (arrondissez le montant-2015) : $ (arrondissez le montant) mois mois mois mois 0 0 0 0 0 Sélectionner 0 0 0 Sélectionner 0 #12;Bourses et prix de

  18. CAMPUSES STUDENTS WORKING AT ASU ALUMNI NEIGHBORS/VISITORS About ASU Calendar Degrees Catalog Online Services Directory Map A-Z Index

    E-print Network

    McGraw, Kevin J.

    Online Services Directory Map A-Z Index > Researcher finds molecular key to colorful red parrot feathers Researcher finds molecular key to colorful red parrot feathers Parrots, long a favorite pet animal, are attractive to owners because of their vibrant colors. But those colors may mean more to parrots than what

  19. Pore formation during hybrid laser-tungsten inert gas arc welding of magnesium alloy AZ31B—mechanism and remedy

    Microsoft Academic Search

    Liming Liu; Gang Song; Guoli Liang; Jifeng Wang

    2005-01-01

    One of the major concerns during high speed welding of magnesium alloys is the presence of porosity in the weld metal that can deteriorate mechanical properties. This study seeks to analyze the presence method and quantity of pore during hybrid laser-tungsten inert gas arc (TIG) welding of magnesium alloy AZ31B by radiography, optical microscopy and electron probe microanalysis (EMPA). At

  20. Wide-field Imaging Survey of Dust Continuum Emissions at lambda = 1.1 mm toward the Chamaeleon and Lupus Regions with AzTEC on ASTE

    SciTech Connect

    Momose, Munetake [College of Science, Ibaraki University, Bunkyo 2-1-1, Mito, Ibaraki 310-8512 (Japan); Hiramatsu, Masaaki [Academia Sinica Institute of Astronomy and Astrophysics, Taiwan (China); Tsukagoshi, Takashi [Institute of Astronomy, Faculty of Science, University of Tokyo (Japan); Shimajiri, Yoshito; Ezawa, Hajime; Kawabe, Ryohei [Nobeyama Radio Observatory, NAOJ (Japan); Ikeda, Norio; Kitamura, Yoshimi; Kamegai, Kazuhisa [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (Japan); Saito, Masao [ALMA Project Office, NAOJ (Japan)

    2009-08-05

    We carried out an imaging survey of dust continuum emissions toward the Chamaeleon and Lupus regions. Observations were made with the 144-element bolometer array camera AzTEC mounted on the 10-meter sub-millimeter telescope ASTE during 2007-2008. The preliminary results of disk search and the cloud structure of Lupus III are presented.

  1. AzTEC/ASTE 1.1-mm survey of SSA22: Counterpart identification and photometric redshift survey of submillimetre galaxies

    E-print Network

    Umehata, H.; Tamura, Y.; Kohno, K.; Hatsukade, B.; Scott, K. S.; Kubo, M.; Yamada, T.; Ivison, R. J.; Cybulski, R.; Aretxaga, I.; Austermann, J.; Hughes, D. H.; Ezawa, H.; Hayashino, T.; Ikarashi, S.; Iono, D.; Kawabe, R.; Matsuda, Y.; Matsuo, H.; Nakanishi, K.; Oshima, T.; Perera, Thushara A.; Takata, T.; Wilson, Graham Wallace; Yun, M. S.

    2014-06-01

    We present the results from a 1.1-mm imaging survey of the SSA22 field, known for having an overdensity of z = 3.1 Lyman ? emitting galaxies (LAEs), taken with the astronomical thermal emission camera (AzTEC) on the Atacama Submillimeter Telescope...

  2. The evaluation of AZ66, an optimized sigma receptor antagonist, against methamphetamine-induced dopaminergic neurotoxicity and memory impairment in mice.

    PubMed

    Seminerio, Michael J; Hansen, Rolf; Kaushal, Nidhi; Zhang, Han-Ting; McCurdy, Christopher R; Matsumoto, Rae R

    2013-06-01

    Sigma (?) receptors have recently been identified as potential targets for the development of novel therapeutics aimed at mitigating the effects of methamphetamine. Particularly, ? receptors are believed to mitigate some of the neurotoxic effects of methamphetamine through modulation of dopamine, dopamine transporters and body temperature. Furthermore, recent evidence suggests that targeting ? receptors may prevent cognitive impairments produced by methamphetamine. In the present study, an optimized ? receptor antagonist, AZ66, was evaluated against methamphetamine-induced neurotoxicity and cognitive dysfunction. AZ66 was found to be highly selective for ? receptors compared to 64 other sites tested. Pretreatment of male, Swiss Webster mice with i.p. dosing of AZ66 significantly attenuated methamphetamine-induced striatal dopamine depletions, striatal dopamine transporter reductions and hyperthermia. Additionally, neurotoxic dosing with methamphetamine caused significant memory impairment in the object recognition test, which was attenuated when animals were pretreated with AZ66; similar trends were observed in the step-through passive avoidance test. Taken together, these results suggest that targeting ? receptors may provide neuroprotection against the neurotoxicity and cognitive impairments produced by methamphetamine. PMID:22932447

  3. Evidences of Arsenic Accumulation in Soils through Irrigation in Maricopa County, AZ Xiaoding Zhuo1, Panjai Prapaipong2, Everett Shock1,2

    E-print Network

    Hall, Sharon J.

    Evidences of Arsenic Accumulation in Soils through Irrigation in Maricopa County, AZ Xiaoding Zhuo1 fractionofAs absorbed Arsenic released in 2 hours 0 100 200 300 400 500 600 1 10 100 1000 10000 100000. ratio of solution to soil 0 200 400 600 800 1000 1200 0 5 10 15 20 25 ratio Asabsorbedppb 1) Arsenic

  4. Organization of World Heritage Cities

    NSDL National Science Digital Library

    2005-01-01

    Created in 1993, the Organization of World Heritage Cities (OWHC) has been given a mandate by the United Nations to protect the cultural, historical, and social heritage of the world's great cities. For a number of years, the organization has worked towards this goal by publishing helpful "how to" materials for any number of interested parties, including city officials, heritage groups, and concerned citizens. Recently, this site was created in an attempt to bring these materials together at one online destination. On this site, visitors can learn about case studies (such as those designed to rehabilitate the urban core of Havana), read publications on how to preserve the built environment, and peruse a list of related links. The publications area is quite strong, as it contains a number of introductory works such as "A History of Architectural Conservation" by Jukka Joklehto and "Standards in Preventive Conservation" by Rebeca Alcantra.

  5. City planning as preventive medicine.

    PubMed

    Corburn, Jason

    2015-08-01

    The health and well-being of rapidly growing urban populations is a global health issue. Cities in the global north and south are faced with rising health inequities - or avoidable differences in health determinants and outcomes based on place, social status and ethnicity. This commentary suggests that focusing only on treatment interventions in cities is likely to fail because populations will be forced to go back into the urban living and working conditions that likely made them sick in the first place. City planning as preventive medicine includes taking a relational and systems approach to urban health, requiring health assessments for all urban policy making, promoting neighborhood health centers as engines of community economic development and gathering place-based health indicator data to track progress and adapt interventions over time as conditions change. PMID:25937591

  6. Star City, Russia Medical Operations

    NASA Technical Reports Server (NTRS)

    Chandler, Michael R.; Senter, Cedric H.; Roden, Sean K.; Gilmore, Stevan; Powers, William E.; Alexander, David J.

    2004-01-01

    Since the beginning of the NASA/Mir missions, NASA has had astronauts in training at the Gagarin Cosmonaut Training Center (GCTC), also known as Star City, with crewmembers currently there to train for the International Space Station missions. Agreements have been reached with all International Partners that allow the crewmember's parent agency to provide a flight surgeon to oversee crewmember health and safety during training away from home. NASA Medical Operations through the Bioastronautics Contract employs flight surgeons to provide medical support for U.S. crewmembers and their support staff. This poster presentation reviews the aspects of NASA medical operations at Star City.

  7. Lobophorin C and D, New Kijanimicin Derivatives from a Marine Sponge-Associated Actinomycetal Strain AZS17

    PubMed Central

    Wei, Rong-Bian; Xi, Tao; Li, Jing; Wang, Ping; Li, Fu-Chao; Lin, Yong-Cheng; Qin, Song

    2011-01-01

    Marine sponge Hymeniacidon sp. was collected from coastal waters of the East China Sea to isolate symbiotic microorganisms. The resulting sponge-associated actinomycete, Streptomyces carnosus strain AZS17, was cultivated in a 20 L volume of medium for production of bioactive secondary metabolites. Bioassay-guided isolation and purification by varied chromatographic methods yielded two new compounds of kijanimicin derivatives, AS7-2 and AS9-12. Their structures were elucidated by spectroscopy and comparison with literatures. Results showed these two compounds were structurally similar to the previously reported compounds lobophorin A and B, yet differed in specific bond forms, stereochemistry and optical activities. The two novel compounds were named lobophorin C and D. In vitro cytotoxicity investigation by MTT assay indicated their selective activities. Lobophorin C displayed potent cytotoxic activity against the human liver cancer cell line 7402, while lobophorin D showed significant inhibitory effect on human breast cancer cells MDA-MB 435. PMID:21556165

  8. Discovery, Synthesis, and Biological Evaluation of Thiazoloquin(az)olin(on)es as Potent CD38 Inhibitors.

    PubMed

    Haffner, Curt D; Becherer, J David; Boros, Eric E; Cadilla, Rodolfo; Carpenter, Tiffany; Cowan, David; Deaton, David N; Guo, Yu; Harrington, Wallace; Henke, Brad R; Jeune, Michael R; Kaldor, Istvan; Milliken, Naphtali; Petrov, Kim G; Preugschat, Frank; Schulte, Christie; Shearer, Barry G; Shearer, Todd; Smalley, Terrence L; Stewart, Eugene L; Stuart, J Darren; Ulrich, John C

    2015-04-23

    A series of thiazoloquin(az)olinones were synthesized and found to have potent inhibitory activity against CD38. Several of these compounds were also shown to have good pharmacokinetic properties and demonstrated the ability to elevate NAD levels in plasma, liver, and muscle tissue. In particular, compound 78c was given to diet induced obese (DIO) C57Bl6 mice, elevating NAD > 5-fold in liver and >1.2-fold in muscle versus control animals at a 2 h time point. The compounds described herein possess the most potent CD38 inhibitory activity of any small molecules described in the literature to date. The inhibitors should allow for a more detailed assessment of how NAD elevation via CD38 inhibition affects physiology in NAD deficient states. PMID:25828863

  9. A Model to Predict the Resulting Grain Size of Friction-Stir-Processed AZ31 Magnesium Alloy

    NASA Astrophysics Data System (ADS)

    Darras, Basil M.

    2012-07-01

    One of the most important issues that hinder the widespread use of friction stir (FS) processing, an effective microstructural modification technique, is the lack of accurate predictive tools that enable the selection of suitable processing parameters to obtain the desired grain structure. In this study, a model that is capable of predicting the resulting average grain size of a FS-processed material from process parameters is presented. The proposed model accounts for both dynamic recrystallization and grain growth. Several AZ31 magnesium samples were FS processed in different combinations of rotational and translational speeds. The thermal fields and resulting average grain size were measured, and the effective strain rates were approximated analytically. The results show that the proposed model is capable of predicting the resulting grain size of FS-processed materials.

  10. Star and Dust Formation Activities in AzTEC-3: A Starburst Galaxy at z equals 5.3

    NASA Technical Reports Server (NTRS)

    Dwek, Eliahu

    2011-01-01

    Analyses of of high-redshift ultraluminous infrared (IR) galaxies traditionally use the observed optical to submillimeter spectral energy distribution (SED) and estimates of the dynamical mass as observational constraints to derive the star formation rate (SFR), the stellar mass, and age of these objects. In this lecture we add this constraint to the analysis of AzTEC-3, a starburst galaxy at z=5.3. We construct different stellar and chemical evolutionary scenarios, constrained to produce the inferred dust mass and observed luminosity before the associated stellar mass exceeds the observational limit. A robust result of our models is that all scenarios require most of the radiating dust mass to have been accreted in molecular clouds. Our new procedure highlights the importance of a multi wavelength approach, and of the use of dust evolution models in constraining the age and the star formation activity and history in galaxies.

  11. Star Dust Formation Activities in AzTEC-3: A Starburst Galaxy at z=5.3

    NASA Technical Reports Server (NTRS)

    Dwek, Eliahu

    2011-01-01

    Analyses of of high-redshift ultraluminous infrared OR) galaxies traditionally use the observed optical to submillimeter spectral energy distribution (SED) and estimates of the dynamical mass as observational constraints to derive the star formation rate (SFR), the stellar mass, and age of these objects. In this lecture we add this constraint to the analysis of AzTEC-3, a starburst galaxy at z=5.3. We construct different stellar and chemical evolutionary scenarios, constrained to produce the inferred dust mass and observed luminosity before the associated stellar mass exceeds the observational limit. A robust result of our models is that all scenarios require most of the radiating dust mass to have been accreted in molecular clouds. Our new procedure highlights the importance of a multi wavelength approach, and of the use of dust evolution models in constraining the age and the star formation activity and history in galaxies.

  12. Star and Dust Formation Activities in AzTEC-3: A Starburst Galaxy at z=5.3

    NASA Technical Reports Server (NTRS)

    Dwek, Eliahu

    2011-01-01

    Analyses of of high-redshift ultraluminous infrared (IR) galaxies traditionally use the observed optical to submillimeter spectral energy distribution (SED) and estimates of the dynamical mass as observational constraints to derive the star formation rate (SFR), the stellar mass, and age of these objects. In this lecture we add this constraint to the analysis of AzTEC-3, a starburst galaxy at z=5.3. We construct different stellar and chemical evolutionary scenarios, constrained to produce the inferred dust mass and observed luminosity before the associated stellar mass exceeds the observational limit. A robust result of our models is that all scenarios require most of the radiating dust mass to have been accreted in molecular clouds. Our new procedure highlights the importance of a multiwavelength approach, and of the use of dust evolution models in constraining the age and the star formation activity and history in galaxies.

  13. Deep wet etching of borosilicate glass and fused silica with dehydrated AZ4330 and a Cr/Au mask

    NASA Astrophysics Data System (ADS)

    Jin, Joo-Young; Yoo, Sunghyun; Bae, Jae-Sung; Kim, Yong-Kweon

    2014-01-01

    This research highlights a superior glass-wet-etch technique which enables a glass wafer to be etched for more than 20 h in 49 wt% hydrofluoric acid (HF) only with Cr/Au film and a common positive photoresist, AZ4330. We demonstrated that pits on the wet-etched glass wafer were generated not only due to HF diffusion through the Cr/Au film but also due to pinholes on the Cr/Au films created by the diffusion of the Cr/Au etchant through a photoresist etching-mask during the Cr/Au wet etching process. These two types of diffusion, HF diffusion and Cr/Au etchant diffusion, were eliminated by the thermal curing of a photoresist (PR), AZ4330, before the Cr/Au wet etching process. The curing process allowed the PR to dehydrate, increased the hydrophobicity, and prevented the diffusion of the hydrophilic HF and Cr/Au etchant. Optimization of the curing process was performed, showing that curing at 130 °C for 20 min was the proper condition. With the optimized process, a 525 ľm thick borosilicate glass wafer was penetrated with 49%wt HF. A fused silica wafer 525 ľm thick was also wet-etched and penetrated with 49 wt% HF at 10 h. Moreover, no pits were found in wet etching of the fused silica for 20 h in 49 wt% HF. These findings demonstrate that the proposed technique allows the wet etching of a glass wafer for more than 20 h in 49%wt HF, the best result thus far. We fabricated a glass substrate with a 217.0 ľm deep cavity and a penetrating through-via using the proposed technique, proving the feasibility of the product as an optical component with a surface roughness of 45.5 Ĺ in the cavity.

  14. Afterimages of the Victorian City

    Microsoft Academic Search

    David L. Pike

    2010-01-01

    As emblematic spaces of social and cultural contamination, the Victorian street and underworld have had remarkable afterlives in twentieth-century reinterpretations of Victorian cityscapes. This article explores what persists in our vision of the nineteenth-century city well over a century after it was, so to speak, first seen, and how what persists impacts on our attempts to reconstruct that act of

  15. THE CITY IS A TEACHER.

    ERIC Educational Resources Information Center

    HOWE, HAROLD, II

    THE PROBLEM OF POVERTY IN THE CITY GHETTO FORMS A COMPLICATED CHAIN OF DISCRIMINATION AND LOST OPPORTUNITIES FOR WHICH ALL AMERICANS PAY. COSTS ARE INCURRED FROM POOR EDUCATION, UNEMPLOYMENT, WASTE OF INDIVIDUAL TALENT, RISING CRIME RATES, MILITARY SERVICE REJECTION RATES, AND OTHER SOCIAL PROBLEMS. THE EDUCATION LINK IN THIS CHAIN IS THE…

  16. The City and the Car

    Microsoft Academic Search

    Mimi Sheller; John Urry

    2000-01-01

    The social sciences have generally ignored the motor car and its awesome consequences for social life, especially in their analysis of the urban. Urban studies in particular has failed to consider the overwhelming impact of the automobile in transforming the time-space 'scapes' of the modern urban\\/suburban dweller. Focusing on forms of mobility into, across and through the city, we consider

  17. City South: A new chapter

    E-print Network

    to ensure City South succeeds. The first is the question of congestion charging along the corridor. "I as congestion charging is, it is the only option unless you have well developed public transport." Brooks understand the huge hostility to charging, but we cannot allow car use to grow unchecked. As unpalatable

  18. Bug City: Aquatic Insects [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…

  19. Bug City: Flies & Mosquitoes [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…

  20. Bug City: Ladybugs & Fireflies [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…