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1

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

Code of Federal Regulations, 2012 CFR

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

2012-07-01

2

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

Code of Federal Regulations, 2012 CFR

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

2012-07-01

3

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

Code of Federal Regulations, 2013 CFR

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

2013-07-01

4

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

Code of Federal Regulations, 2013 CFR

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

2013-07-01

5

78 FR 48303 - Establishment of Class E Airspace; Tuba City, AZ  

Federal Register 2010, 2011, 2012, 2013

...Establishment of Class E Airspace; Tuba City, AZ AGENCY: Federal Aviation Administration...Class E en route airspace at the Tuba City VHF Omni-Directional Radio Range...Air Navigational Aid (VORTAC), Tuba City, AZ. In that rule, an error...

2013-08-08

6

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

Federal Register 2010, 2011, 2012, 2013

...navigable waters of the Colorado River in Lake Havasu, Lake Havasu City...is to be held on the Colorado River in Lake Havasu City, Arizona. This...zone encompasses the waters of Lake Havasu on the Colorado River and is bound by the...

2013-03-25

7

Habitat Suitability Index Models: Black Bullhead  

USGS Publications Warehouse

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

Stuber, Robert J.

1982-01-01

8

Phoenix, AZ, USA  

NASA Technical Reports Server (NTRS)

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.

1973-01-01

9

HISTORICAL MONITORING OF BIOMARKERS OF EXPOSURE OF BROWN BULLHEAD  

EPA Science Inventory

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

10

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

11

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

Federal Register 2010, 2011, 2012, 2013

...maps. The Act requires such maps to be developed in consultation...has submitted noise exposure maps that are found by FAA to be...taken or proposes to take to reduce existing non-compatible uses...review of the noise exposure maps and accompanying...

2013-11-29

12

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, ...

13

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

PubMed

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

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

2013-06-01

14

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 ...

15

Behavioral and metabolic aspects of low temperature dormancy in the brown bullhead, Ictalurus nebulosus  

Microsoft Academic Search

1.Behavioral and physiological measurements were made during the winter at low temperatures to evaluate cold temperature dormancy in the brown bullhead.2.At 17°C and when slowly cooled to 3°C the bullheads often buried themselves in the mud (Fig. 1). Animals buried at 3°C were not immobilized and would emerge from the mud following a disturbance.3.No readjustment of the thermoregulatory mechanisms was

Larry I. Crawshaw; Daniel E. Lemons; Marsha Parmer; Jeffrey M. Messing

1982-01-01

16

Relationship between liver tumors and age in brown bullhead populations from two Lake Erie tributaries.  

PubMed

We compared liver tumor frequencies, and age and length characteristics of brown bullheads (Ictalurus nebulosus) of greater than 250 mm total length from two Lake Erie tributaries. Bullheads taken from Old Woman Creek (n = 144) had no grossly observable liver tumors, while those collected in the highly industrialized Black River (n = 532) had a 30% frequency of grossly visible liver tumors during 1981-1982. Liver lesions diagnosed histologically in a randomly collected sample (n = 125) of brown bullheads from the Black River included both biliary and hepatic lesions, with cancerous neoplasms occurring in 38.4% of the fish. Black River bullheads of combined ages 4 and 5 had a significantly (p less than or equal to 0.05) greater prevalence of biliary carcinomas (35.5%) than those of ages 2 and 3 combined (18.4%). Biliary carcinoma was significantly more prevalent than hepatocellular carcinoma in age 4 fish (sexes combined) and in males of ages 3 and 4. The prevalence of hepatocellular carcinoma was significantly higher in females than in males. Age distributions of bullheads differed significantly between the two sites, while length distributions were similar. No brown bullheads of ages 6 or 7 were collected in the Black River, while these age groups composed 18% of the catch in Old Woman Creek. Brown bullheads of age 5 were almost six times more numerous in the Old Woman Creek than in Black River collections. These age and length distributions are consistent with the hypothesis that brown bullheads in the Black River were subjected to an age-selective mortality associated with high prevalences of liver carcinoma. PMID:2360040

Baumann, P C; Harshbarger, J C; Hartman, K J

1990-05-01

17

Corrosion behaviour of AZ21, AZ501 and AZ91 in sodium chloride  

Microsoft Academic Search

The corrosion behaviour of AZ21, AZ501 and AZ91 was studied in 1 N NaCl at pH 11 by measuring electrochemical polarization curves, electrochemical AC impedance spectroscopy (EIS) and simultaneously measuring the hydrogen evolution rate and the magnesium dissolution rate. The corrosion rates increased in the following order: AZ501< AZ21< AZ91. The corrosion behaviour was related to alloy microstructure as revealed

Guangling Song; Andrej Atrens; Xianliang Wu; Bo Zhang

1998-01-01

18

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

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

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

1999-01-01

19

Factors influencing the spatial distribution patterns of the bullhead ( Cottus gobio L., Teleostei Cottidae): a multi-scale study  

Microsoft Academic Search

We used general linear modelling to assess the influence of environmental variables on the spatial distribution patterns of the bullhead (Cottus gobio) at stream system, site, and microhabitat scales in southwestern France. Bullheads occurred at 67 sites (out of 554 sampling sites), chiefly close to the source, in small and shallow streams. Population density at a site was primarily influenced

M. Legalle; F. Santoul; J. Figuerola; S. Mastrorillo; R. Céréghino

2005-01-01

20

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

SciTech Connect

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

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

2000-02-01

21

75 FR 19246 - Safety Zone; Desert Storm, Lake Havasu, AZ  

Federal Register 2010, 2011, 2012, 2013

...waters of the Colorado River in Lake Havasu, Lake Havasu City...region of the Colorado River in Lake Havasu City, Arizona...Safety zone; Desert Storm, Lake Havasu, AZ (a) Location...Thompson Bay of the Colorado River and land adjacent to...

2010-04-14

22

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

USGS Publications Warehouse

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.

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

2001-01-01

23

Variable growth and longevity of yellow bullhead (Ameiurus natalis) in the Everglades of south Florida, USA  

USGS Publications Warehouse

Yellow bullhead (Ictaluridae: Ameiurus natalis) is the most abundant ictalurid catfish in the Everglades of southern Florida, USA, and, as both prey and predator, is one of many essential components in the ecological-simulation models used in assessing restoration success in the Everglades. Little is known of its biology and life history in this southernmost portion of its native range; the present study provides the first estimates of age and growth from the Everglades. In total, 144 yellow bullheads of 97-312 mm total length (TL) were collected from canals and marshes of the Everglades between April 2000 and January 2001, and from October 2003 to February 2005. Fish were aged using cross-sections of pectoral spines and ranged from 1-12 years, with the maximum age almost twice that of any yellow bullhead previously reported. Yellow bullheads from south Florida grew relatively rapidly during their first 3 years, but after age 5 growth slowed and fish approached an asymptote of ???214 mm TL. Compared to other populations in the United States, yellow bullhead in the Everglades grew relatively slowly, were smaller at age overall, but survived to older ages. ?? 2009 Blackwell Verlag GmbH.

Murie, D. J.; Parkyn, D. C.; Loftus, W. F.; Nico, L. G.

2009-01-01

24

The effect of contaminated sediments on fecundity of the brown bullhead in three Lake Erie tributaries  

USGS Publications Warehouse

Female brown bullhead (Ameiurus nebulosus) were collected from three Lake Erie tributaries (Ohio) from 8 to 25 May 1989, to determine the effects of contaminated sediments on reproductive potentials. Fish obtained from the Black and Cuyahoga rivers, which contain sediments with elevated concentrations of metals, PCBs, and PAHs, were compared with fish collected in Mud Brook, a tributary of the Huron River, which was selected as our reference site. Fecundity, egg diameter, fish length and weight, and the presence of external abnormalities were recorded for each fish. Brown bullhead from the contaminated sites were larger then those from the reference site and fecundity was significantly (P < 0.05) different in all three river systems. Those from the most polluted river (Cuyahoga River) had the greatest number of eggs per individual female. The high frequency of external abnormalities observed on brown bullhead from the contaminated sites did not appear to have a detrimental influence on fecundity. These results suggest that fecundity of the brown bullhead was not adversely affected in ecosystems altered by the presence of contaminated sediments. Increased fecundity of the brown bullhead from impacted rivers may be the result of reduced competition for an abundant invertebrate food source and limited predation by other fish species whose numbers are largely depleted in these degraded systems.

Lesko, Lynn T.; Smith, Stephen B.; Blouin, Marc A.

1996-01-01

25

Induction of glutathione S-transferase activity and protein expression in brown bullhead (Ameiurus nebulosus) liver by ethoxyquin.  

PubMed

The inducibility of hepatic cytosolic glutathione S-transferases (GSTs) was examined in brown bullheads, a freshwater fish that is highly susceptible to hepatic neoplasia following exposure to carcinogen-contaminated sediments. Juvenile bullheads were fed a semi-purified antioxidant-free diet supplemented with ethoxyquin (0.5% w/w dissolved in 3% corn oil), a prototypical rodent GST-inducing agent, twice daily for 14 days. Control bullheads received the antioxidant-free diet supplemented with corn oil (3% w/w). A significant increase (1.6-fold, p < or = 0.01) in hepatic cytosolic GST activity toward 1-chloro-2,4-dinitrobenzene (CDNB) was observed in the ethoxyquin-treated bullheads relative to control fish. A trend toward increased GST-NBC activity was observed in the ethoxyquin-treated fish (1.2-fold, p = 0.06), whereas no treatment-related effects were observed on GST activities toward ethacrynic acid (ECA). In contrast, GST activity toward (+/-)-anti-benzo[a]pyrene-trans-7,8-dihydrodiol-9,10-epoxide (BPDE) was repressed in affinity-purified cytosolic fractions prepared from ethoxyquin-treated bullheads relative to control bullheads. Silver staining and densitometric analysis of isoelectric-focused, affinity-purified GST proteins revealed increased expression of two basic GST-like isoforms in ethoxyquin-treated fish. In summary, exposure to ethoxyquin increases brown bullhead GST-CDNB catalytic activity and hepatic cationic GST protein expression. However, the increase in overall GST-CDNB activity by ethoxyquin is associated with repression of GST-BPDE activity, suggesting differential effects on hepatic bullhead GST isoforms by ethoxyquin. The potential repression of bullhead GST isoforms that conjugate the carcinogenic metabolites of PAH metabolism under conditions of environmental chemical exposure could be a contributing factor in the sensitivity of bullheads to pollutant-associated neoplasia. PMID:11399793

Henson, K L; Stauffer, G; Gallagher, E P

2001-07-01

26

Ontogenetic Microhabitat Shifts in the Bullhead, Cottus gobio L.,in a Fast Flowing Stream  

Microsoft Academic Search

We investigated differences in microhabitat preference curves for bullheads, Cottus gobio L., of different size-classes during low flow periods, and evaluated the influence of such differences on habitat use through Weighted Usable Area (WUA) predictions in relation to river flow in a piedmont stream in Southwest France. Water depth, current velocity, and substratum composition were used to calculate proportional use

Milčne Legalle; Sylvain Mastrorillo; Frédéric Santoul; Régis Céréghino

2005-01-01

27

Biomarkers Indicate Health Problems in Brown Bullheads from the Industrialized Schuylkill River, Philadelphia  

Microsoft Academic Search

We used biomarkers to assess the health of two populations of brown bullheads Ameiurus nebulosus one from an urban, industrialized section of the Schuylkill River (SR), Philadelphia, Pennsylvania, and the other from Hopkins Pond (HP), in suburban New Jersey, which was not affected by industry. We evaluated health using histopathology, condition factor (K), hepatosomal index (HSI), prevalence of parasites, health

Anthony C. Steyermark; James R. Spotila; Deborah Gillette; Hadar Isseroff

1999-01-01

28

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...

29

Genetic analysis of potential postglacial watershed crossings in Central Europe by the bullhead (Cottus gobio L.)  

Microsoft Academic Search

Natural colonizations across watersheds have been frequently proposed to explain the present distributions of many freshwater fish species. However, detailed studies of such potential watershed crossings are still missing. Here, we investigated potential postglacial watershed crossings of the widely distributed European bullhead (Cottus gobio L.) in two different areas along the Rhine-Rhône watershed using detailed genetic analysis. The main advantage

P. VONLANTHEN; L. EXCOFFIER; D. BITTNER; H. PERSAT; S. NEUENSCHWANDER; C. R. LARGIADČR

2007-01-01

30

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

PubMed

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 (32)P-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. (32)P-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. PMID:21995877

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

2011-12-01

31

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,...

32

Biomarkers of exposure of brown bullheads (Ameiurus nebulosus) to contaminants in the lower Great Lakes, North America  

SciTech Connect

Brown bullheads (Ameiurus nebulosus) from three contaminated sites (Detroit River, Hamilton Harbour, and Black River) and two relatively clean reference sites (Old Woman Creek and Bay of Quinte) in the lower Great Lakes were monitored for several biomarkers of exposure to PAHs. Bullheads from the contaminated sites had elevated hepatosomatic indices, increased ethoxyresorufin-O-deethylase (EROD) activity, decreased hepatic retinoid stores, and a greater incidence of hepatic neoplasms. Fluorescent aromatic compounds (FACs) in the bile were also elevated in bullheads from the Black River and Hamilton Harbour in comparison to fish from reference sites. A correlation was found between reduction of hepatic retinoid stores and induction of hepatic EROD activity in bullheads. Principal component analysis of biomarker data demonstrated that biomarker patterns in Detroit River bullheads were different from those of Black River and Hamilton Harbour bullheads. Biomarkers in fish are useful monitoring tools for detecting contamination of the aquatic environment, but interpretation of results is limited by within- and between-site variability in the responses, some of which may be explained by mobility of the fish. In contaminated areas, bile fluorescent aromatic compounds appear to be the best indicator of recent exposure to polynuclear aromatic hydrocarbons, whereas responses to other biochemical biomarkers appear to be over a longer time period.

Arcand-Hoy, L.D.; Metcalfe, C.D. [Trent Univ., Peterborough, Ontario (Canada)

1999-04-01

33

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

USGS Publications Warehouse

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.

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

2006-01-01

34

CUMULATIVE IMPACTS ASSESSMENT ALONG A LARGE RIVER, USING BROWN BULLHEAD CATFISH (AMEIURUS NEBULOSUS) POPULATIONS  

Microsoft Academic Search

The effects of point-source and diffuse discharges on resident populations of brown bullhead catfish ( Ameiurus nebulosus (LeSueur, 1819)) in the Waikato River (New Zealand) were assessed at sites both upstream and downstream of point-source discharges. At each site, the population parameters, relative abundance, age structure, and individual indices, such as condition factor, organ (gonad, liver, and spleen) to somatic

David W. West; Nicholas Ling; Brendan J. Hicks; Louis A. Tremblay; Nick D. Kim; Michael R. van den Heuvel

2006-01-01

35

Postglacial colonization of Northern Europe by distinct phylogeographic lineages of the bullhead, Cottus gobio.  

PubMed

Three major phylogeographic lineages of the cottid fish Cottus gobio (bullhead) were identified in northern Europe from mitochondrial DNA sequences and allozyme data. The largely separate freshwater distributions of the lineages demonstrate distinct postglacial colonization histories. West of the Baltic Sea, Swedish lakes were invaded from the southwest (Germany). Another, eastern lineage has colonized the inland waters northeast and east of the Baltic, from refugia in northwest Russia; this lineage comprises a distinct subgroup found only from Estonia. The third lineage, found south and southeast of the Baltic, probably descended from rivers draining to the Black Sea from the north (e.g. Dnepr). In coastal waters of the Baltic Sea, and in near-coast inland waters, the lineages are now found intermixed in various combinations. The alternating fresh- and saltwater phases of the Baltic basin have variously enabled and disabled the use of coastal waters as colonization routes. Hypotheses on the chronology of dispersal and lineage mixing can be based on the distribution of the marker genes and the paleohydrographical record. The diversity of the Fennoscandian bullhead thus comprises anciently diverged (probably mid-Pleistocene) refugial lineages that in their freshwater range constitute distinct evolutionarily significant units. The thorough mixing of the various genomic origins in and around the Baltic, however, refutes the controversial view of distinct species status for the western and eastern ('Cottus koshewnikowi') bullheads. The postglacial contact of the lineages has created new diversity that cannot be interpreted in a conventional hierarchical framework of taxonomic or conservation units. PMID:11555242

Kontula, T; Väinölä, R

2001-08-01

36

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

USGS Publications Warehouse

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

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

2006-01-01

37

6. Frisco Street streetscape, looking southeast. AZ167 and AZ168 (Archie ...  

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

6. Frisco Street streetscape, looking southeast. AZ-167 and AZ-168 (Archie Morrison Rental Houses) at left. - Clifton Townsite, Confluence of Chase Creek & San Francisco River, Clifton, Greenlee County, AZ

38

Az-Tech Medicine.  

ERIC Educational Resources Information Center

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

Nicholson, Rob

2000-01-01

39

Behavioral response of carp, Cyprinus carpio , and black bullhead, Ictalurus melas , from Italy to gas supersaturated water  

Microsoft Academic Search

A nine chambered circular apparatus (rosette) was used to test the ability of carp (Cyprinus carpio) and black bullhead (Ictalurus melas) from Italy, to detect and avoid lethal concentrations of gas supersaturated water. These species are important food fish and are being considered for mass culture in warm water discharges in Italy. Neither species immediately avoided gas supersaturated water. Although

Robert H. Gray; Thomas L. Page; Marco G. Saroglia

1983-01-01

40

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...

41

FORMATION AND PERSISTANCE OF DNA ADDUCTS IN THE LIVER OF BROWN BULLHEADS EXPOSED TO BENZO(A)PYRENE  

EPA Science Inventory

The formation and persistence of benzo[a]pyrene (BP)-DNA adducts in the liver of brown bullheads (Ictalurus nebulosus) treated with the hydrocarbon (20 mg/kg body wt, i.p.) was investigated using the 32P-postlabeling assay. he highest level of covalent binding of BP to liver DNA ...

42

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 ...

43

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

SciTech Connect

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.

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

1994-08-01

44

75 FR 20920 - Safety Zone; Lake Havasu Grand Prix, Lake Havasu, AZ  

Federal Register 2010, 2011, 2012, 2013

...1625-AA00 Safety Zone; Lake Havasu Grand Prix, Lake Havasu, AZ AGENCY: Coast Guard, DHS. ACTION...temporary safety zone upon the navigable waters of Lake Havasu on the Colorado River in Lake Havasu City, Arizona for the Lake Havasu...

2010-04-22

45

The AzTEC Mathematics Project (AMP).  

ERIC Educational Resources Information Center

The AzTEC Mathematics Project (AMP) is a statewide partnership among Arizona's Regents universities and state community colleges, partner school districts, and economic communities. AzTec is committed to preparing highly qualified K-12 mathematics and science teachers. AMP targeted Native American teachers and teachers of Native American students…

Johnson, Gae R.

46

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

SciTech Connect

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

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

1997-02-01

47

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

PubMed

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

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

2010-07-01

48

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

USGS Publications Warehouse

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.

Yang, X.; Baumann, P. C.

2006-01-01

49

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

USGS Publications Warehouse

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.

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

2014-01-01

50

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

51

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

Microsoft Academic Search

BACKGROUND: Within chromatin, the histone variant H2A.Z plays a role in many diverse nuclear processes including transcription, preventing the spread of heterochromatin and epigenetic transcriptional memory. The molecular mechanisms of how H2A.Z mediates its effects are not entirely understood. However, it is now known that H2A.Z has two protein isoforms in vertebrates, H2A.Z-1 and H2A.Z-2, which are encoded by separate

Deanna Dryhurst; Toyotaka Ishibashi; Kristie L Rose; José M Eirín-López; Darin McDonald; Begonia Silva-Moreno; Nik Veldhoen; Caren C Helbing; Michael J Hendzel; Jeffrey Shabanowitz; Donald F Hunt; Juan Ausió

2009-01-01

52

PCB accumulation in Hudson River pumpkinseed sunfish and bullhead: Influences of invertebrate prey  

SciTech Connect

Hudson River sediments are contaminated with PCBs, and these toxic compounds are also in the water and have accumulated in food chains. The relative importance of exposure by fish to contaminated water vs. contaminated prey was unknown. further, is was not known if difference in diet could influence fish PCB levels. Invertebrates and fish were sampled in different habitats to address these issues. Invertebrate communities differed in several ecological measures between two different plant beds, and among experimentally manipulated habitats in one plant bed. Communities often differed significantly in parameters such as total invertebrate density, densities of individual taxa, taxonomic richness and similarity, and size distributions; some taxa were also absent from one habitat but present in another. Total PCBs differed significantly for invertebrate communities between the two plant beds (9.4 vs. 31.4 [mu]g/g), and between some of the communities in the manipulated habitats (1.8 vs 5.3 [mu]g/g). These differences did not translate into difference in PCBs among fish that fed in the different habitats. However, bullhead had significantly higher levels than pumpkinseed (15.4 vs. 6.9 [mu]g/g). Yearling pumpkinseed that fed on Hudson River invertebrates had 5x the PCB levels of pumpkinseed exposed for the same period to the water but not to the prey, and 18x as much PCBs as fish unexposed to either Hudson River water or prey. Further, fish that fed on local prey had a higher proportion of high-Cl isomers than those exposed only to the contaminated water. Fish that fed in different habitats did not have different PCB levels. Thus, the role of diet needs further experimentation, but it is clear that local prey are the major route for PCB accumulation in yearling pumpkinseed.

Feldman, R.S.

1992-01-01

53

The Food and Growth of the Young of the Common Bullhead, Ameiurus Nebulosus Nebulosus (LeSueur), in Cayuga Lake, New York  

Microsoft Academic Search

An analysis is presented of the food of 170 specimens of the young of the common bullhead, Ameiurus nebulosus nebulosus (LeSueur), taken at intervals from June 21 to October 10, 1938, in quiet coves of Cayuga Lake, Ithaca, New York. A large variety of organisms were utilized for food. The main staples were Crustacea (approximately 60 per cent) and Diptera

Edward C. Raney; Dwight A. Webster

1940-01-01

54

Prevalence of Liver Lesions in Brown Bullheads from a Polluted Site and a Nonpolluted Reference Site on the Hudson River, New York  

Microsoft Academic Search

Two groups of Hudson River brown bullheads Ictalurus nebulosus were collected during fall 1987 in a preliminary investigation of the potential value of these fish as indicators of contamination of this body of water. Prevalence of some specific lesions, determined through histological examination of liver samples, may serve as an indicator of exposure to chemical contaminants. Significantly higher prevalences of

Paul R. Bowser; Daniel Martineau; Ronald Sloan; Mark Brown; Cynthia Carusone

1990-01-01

55

Az EU-integráció hatása a magyar munkaer?piac területi széttöredezettségére  

Microsoft Academic Search

Az európai gazdasági és szociális tér még ma is er?sen tagolt annak ellenére, hogy Nyugat- Európában az elmúlt fél évszázadban állandó változások jellemezték az állam, a gazdaság és a társadalmi struktúrák kapcsolatrendszerét. A globalizációs folyamatok hatására az egyes régiók és városok különböz?képpen reagáltak, adottságaik és az alkalmazott stratégiák függvényében nyertesek vagy vesztesek lettek. A globalizáció mellett az európai térségek integrációját

Henriett Emese

2005-01-01

56

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

Federal Register 2010, 2011, 2012, 2013

...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...

2012-04-03

57

Az Egységes Szakképzési Minőségirányítási Keretrendszer bevezetésének szükségessége a felnőttképzésben  

Microsoft Academic Search

Magyarország úttörő szerepet vállalt az EU által szorgalmazott és elfogadott szakképzésre vonatkozó minőségbiztosítási rendszerének kialakításában és bevezetésében. Ennek megvalósítására született az Új Magyarország Fejlesztési Terv Társadalmi Megújulás Operatív Programja: „A képzés minőségének és tartalmának fejlesztése” című projekt (TÁMOP2.2.1.). A program keretében kidolgozásra került az Egységes Szakképzési Minőségirányítási Keretrendszer (ESZMK), amely egy olyan formai és tartalmi követelményrendszert jelent, ami egységesíti és

Handa Lászlóné

58

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

Code of Federal Regulations, 2010 CFR

...the first day of the event, the last Thursday of May each year, from 3 p.m. PDT to 5 p.m. PDT, 2.) the second day of the event, Friday, from 8 a.m. PDT to 2 p.m. PDT, and from 3:30 p.m. PDT to 6 p.m. PDT, 3.) the...

2010-07-01

59

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

Code of Federal Regulations, 2011 CFR

...AND MARINE PARADES SAFETY OF LIFE ON NAVIGABLE WATERS § 100...support to ensure the safety of life and property. A Coast Guard-National...necessary for the protection of life and property. The Patrol Commander...Hotel. Laughlin Aquamoto Sports Challenge and Expo...

2011-07-01

60

Histopathological effects of sublethal exposure to phenol on two variously pre-stressed populations of bullhead (Cottus gobio L. )  

SciTech Connect

Phenol is a common pollutant of aquatic ecosystems, into which it can be introduced by industrial waste water of different kinds (from refineries, chemical plants and paper mills), communal sewage, or decaying vegetation. In fish a very broad spectrum of toxic effects of phenol has been reported, ranging from disturbances in behavior to impairment of growth and reproduction or even serious organic damage. It has also been observed that previous exposure to phenol confers a certain degree of resistance. In the investigation reported here, the histopathological effects of phenol intoxication on bullhead (Cottus gobio) were studied, and the reactions of variously [open quotes]pre-exposed[close quotes] populations compared. 17 refs., 6 figs., 1 tab.

Bucher, F.; Hofer, R. (Univ. of Innsbruck (Austria))

1993-08-01

61

Producing Ultrafine-Grained AZ91 from AsCast AZ91 by FSP  

Microsoft Academic Search

In this investigation SiC particles were added to as-cast AZ91 magnesium alloy and AZ91\\/SiC surface nanocomposite layer with nano-grain structure was produced via friction stir processing (FSP). Effects of process parameters, such as the rotational and traverse speeds, the FSP pass numbers and the rotational direction of FSP tool on the powder distribution pattern, microstructure, and microhardness of the developed

P. Asadi; M. K. Besharati Givi; G. Faraji

2010-01-01

62

Tank 241-AZ-102 tank characterization plan  

SciTech Connect

The Defense Nuclear Facilities Safety Board has advised the DOE to concentrate the near-term sampling and analysis activities on identification and resolution of safety issues. The Data Quality Objective (DQO) process was chosen as a tool to be used in the resolution of safety issues. As a result, a revision in the Federal Facilities Agreement and Consent Order (Tri-Party Agreement) milestone M-44 has been made, which states that ``A Tank Characterization Plan (TCP) will also be developed for each double-shell tank (DST) and single-shell tank (SST) using the DQO process ... Development of TCPs by the DQO process is intended to allow users to ensure their needs will be met and that resources are devoted to gaining only necessary information``. This document satisfies that requirement for tank 241-AZ-102 (AZ-102) sampling activities. Tank AZ-102 is currently a non-Watch List tank, so the only DQOs applicable to this tank are the safety screening DQO and the compatibility DQO, as described below. The current contents of Tank AZ-102, as of October 31, 1994, consisted of 3,600 kL (950 kgal) of dilute non-complexed waste and aging waste from PUREX (NCAW, neutralized current acid waste). Tank AZ-102 is expected to have two primary layers. The bottom layer is composed of 360 kL of sludge, and the top layer is composed of 3,240 kL of supernatant, with a total tank waste depth of approximately 8.9 meters.

Schreiber, R.D.

1995-02-06

63

Tank 241-AZ-101 tank characterization plan  

SciTech Connect

The Defense Nuclear Facilities Safety Board has advised the DOE to concentrate the near-term sampling and analysis activities on identification and resolution of safety issues. The Data Quality Objective (DQO) process was chosen as a tool to be used in the resolution of safety issues. As a result, A revision in the Federal Facilities Agreement and Consent Order (Tri-Party Agreement) milestone M-44 has been made, which states that ``A Tank Characterization Plan (TCP) will also be developed for each double-shell tank (DST) and single-shell tank (SST) using the DQO process. Development of TCPs by the DQO process is intended to allow users to ensure their needs will be met and that resources are devoted to gaining only necessary information``. This document satisfies that requirement for Tank 241-AZ-101 (AZ-101) sampling activities. Tank AZ-101 is currently a non-Watch List tank, so the only DQOs applicable to this tank are the safety screening DQO and the compatibility DQO, as described below. The contents of Tank AZ-101, as of October 31, 1994, consisted of 3,630 kL (960 kgal) of dilute non-complexed waste and aging waste from PUREX (NCAW, neutralized current acid waste). Tank AZ-101 is expected to have two primary layers. The bottom layer is composed of 132 kL of sludge, and the top layer is composed of 3,500 kL of supernatant, with a total tank waste depth of approximately 8.87 meters.

Schreiber, R.D.

1995-02-06

64

Dendritic solidification of magnesium alloy AZ91  

Microsoft Academic Search

The magnesium alloy AZ91 has been studied under different solidification conditions, to establish the details of the as-cast\\u000a structure. The electron backscattered pattern (EBSP) technique has been used to determine the crystallographic directions\\u000a of the dendrite stem and the secondary arms. Under unidirectional solidification conditions, two different stem directions\\u000a were found: at a low temperature gradient and high growth velocity,

K. Pettersen; O. Lohne; N. Ryum

1990-01-01

65

Microstructural stability and high-temperature mechanical properties of AZ91 and AZ91 + 2RE magnesium alloys  

Microsoft Academic Search

The effects of 2wt.% rare earth element addition on the microstructure evolution, thermal stability and shear strength of AZ91 alloy were investigated in the as-cast and annealed conditions. The as-cast structure of AZ91 consists of ?-Mg matrix and the ?-Mg17Al12 intermetallic phase. Due to the low thermal stability of this phase, the strength of AZ91 significantly decreased as the temperature

R. Mahmudi; F. Kabirian; Z. Nematollahi

2011-01-01

66

Tank 241-AZ-101 and Tank 241-AZ-102 Airlift Circulator Operation Vapor Sampling and Analysis Plan  

Microsoft Academic Search

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) and during the initial operation (''bump'') of the tank 241-AZ-101 mixer pumps. The purpose of the ALC operation is to support portions of the operational

1999-01-01

67

15. View to the northwest along railroad tracks. AZ180 (Arizona ...  

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

15. View to the northwest along railroad tracks. AZ-180 (Arizona and New Mexico Railroad Passenger Depot) at left. In the background can be seen, left to right, AZ-178 (Arizona Copper Company Office), AZ-177 (Arizona Copper Company Library Hall), AZ-179 (Park Avenue Bridge) and AZ-183 (La Casa Grande). - Clifton Townsite, Confluence of Chase Creek & San Francisco River, Clifton, Greenlee County, AZ

68

OKTATÁSÜGYI VÁLTOZÁSOK KELET-KÖZÉP-EURÓPÁBAN AZ 1990ES ÉVEKBEN  

Microsoft Academic Search

A tanulmány a kelet-közép-európai térségben a rendszerváltozást követ? évtizedben le- zajlott oktatásügyi változásokat, ezek fontosabb mozzanatait és tendenciáit mutatja be. Az áttekintés - praktikus okokból, a szakirodalmi tájékozódás lehet?ségeit is figyelembe véve - a térség négy államára, az úgynevezett \\

MAGYAR PEDAGÓGIA; Kelemen Elemér

69

ANALYSIS RESULTS FOR BUILDING 241 702-AZ A TRAIN  

SciTech Connect

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

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

2006-12-13

70

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

Federal Register 2010, 2011, 2012, 2013

...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...

2013-11-29

71

Tank 241-AZ-101 and Tank 241-AZ-102 Airlift Circulator Operation Vapor Sampling and Analysis Plan  

SciTech Connect

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) and during the initial operation (''bump'') of the tank 241-AZ-101 mixer pumps. 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 (241-142-702) 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). In addition the last two vapor samples will be collected from the headspace of tank 241-AZ-101 during the operation of the mixer pumps. Each mixer pump will be operated for approximately 5 minutes. 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. The following sections provide the general methodology and procedures to be used in the preparation, retrieval, transport, analysis, and reporting of results from vapor samples retrieved during the ALC testing.

TEMPLETON, A.M.

1999-12-07

72

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

Federal Register 2010, 2011, 2012, 2013

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

2013-01-17

73

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

Microsoft Academic Search

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

1999-01-01

74

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

SciTech Connect

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.

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

1997-07-01

75

Genetic diversity and comparative analysis of gene expression between Heterorhabditis bacteriophora Az29 and Az36 isolates: uncovering candidate genes involved in insect pathogenicity.  

PubMed

Entomopathogenic nematode Heterorhabditis bacteriophora Az29 and Az36 isolates with different virulence against Popillia unipuncta and soil survival time were isolated from the Azorean archipelago (Portugal) and used for the study. RAPD analysis revealed a very low-level of genetic diversity (GD(axenic Az36 isolate)(axenic Az29 isolate)=0.2338ą0.0541) between axenic Az29 and Az36 isolates, and a relative low-level of diversity (GD(Az36 isolate)(Az29 isolate)=0.3366ą0.0471) between Az29 and Az36 isolates. To unravel the molecular differences, a suppressive subtractive hybridization library was constructed from the parasitic stage. Assembling 150 high quality ESTs produced 70 singletons and 17 contigs. BLAST analysis revealed that 48 ESTs showed significant similarity to known protein and 39 ESTs had no significant hits in the database, perhaps representing novel genes. Functional annotation revealed some of these genes to be involved in metabolism, cellular process and signaling, information storage and processing, stress response and host-parasite interactions. Genes with a role in the parasitism process were identified including lectin, metalloprotease, enolase, chitinase, surface-associated antigen, and as well as genes (aquaporin, Hsp70A, Hsp10 and Hsp20) essential for stresses tolerance. The work described here provides the molecular data necessary for investigating the fundamental molecular aspects of host-parasite interactions. Future investigations should be focused on determining the molecular mechanism of those genes in entomopathogenic nematode life cycle. PMID:22206770

Hao, You-Jin; Montiel, Rafael; Lucena, Miguel A; Costa, Miguel; Simoes, Nelson

2012-02-01

76

19. View to the north of Riverside Avenue. AZ196(J. C. ...  

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

19. View to the north of Riverside Avenue. AZ-196(J. C. Gatti House) at left Part of AZ-197 (Shannon Copper Company Store) can be seen in group of buildings at right - Clifton Townsite, Confluence of Chase Creek & San Francisco River, Clifton, Greenlee County, AZ

77

Linearity and Enhanced Sensitivity of the Shipley AZ-1350B Photoresist.  

National Technical Information Service (NTIS)

The properties of the Shipley AZ-1350-B positive photoresist used with the Shipley AZ-303A developer were investigated. It was found that the use of AZ-303A developer results in a significant improvement of the sensitivity and the linearity of the photore...

A. C. Livanos A . Katzir J. B. Shellan A. Yariv

1976-01-01

78

Great Zoom into Tucson, AZ: Sabino Canyon  

NSDL National Science Digital Library

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.

Shirah, Greg; Mitchell, Horace; Newcombe, Marte; Sorooshian, Soroosh

2003-06-10

79

Great Zoom into the Grand Canyon, AZ  

NSDL National Science Digital Library

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.

Shirah, Greg; Mitchell, Horace; Newcombe, Marte; Williams, Darrel

2003-01-14

80

Simultaneous enhancement of tensile/compressive strength and ductility of magnesium alloy AZ31 using carbon nanotubes.  

PubMed

AZ31 nanocomposite containing carbon nanotube (CNT) reinforcement was fabricated using solidification processing followed by hot extrusion. The CNT reinforcement was integrated with AZ31 using an Al foil method. The AZ31 nanocomposite exhibited slightly smaller grain and intermetallic particle sizes than monolithic AZ31, reasonable CNT distribution, dominant (10 - 11) texture in the transverse and longitudinal directions unlike monolithic AZ31, and 48% higher hardness than monolithic AZ31. Compared to monolithic AZ31, the AZ31 nanocomposite exhibited higher 0.2%TYS, UTS, tensile failure strain and tensile work of fracture (WOF) (+10%, +17%, +68% and +92%, respectively). Similarly, compared to monolithic AZ31, the AZ31 nanocomposite exhibited higher 0.2%CYS, UCS, average compressive failure strain and compressive WOF (+58%, +3%, +5% and +17%, respectively). Inclusive of crystallographic texture changes, the effect of CNT integration on the enhancement of tensile and compressive properties of AZ31 is investigated in this paper. PMID:20352742

Paramsothy, M; Hassan, S F; Srikanth, N; Gupta, M

2010-02-01

81

Inverted disk centrifugal atomization of AZ91 magnesium alloy  

Microsoft Academic Search

Magnesium AZ91 alloy powder was produced by centrifugal atomization under various conditions using an inverted disk atomizer. The particle size distribution was obtained as a function of the disk shape and rotation speed. The microstructure of particles and their shape were examined and characterized. Their cooling rates were obtained from theoretical relations and related to the secondary dendrite arm spacing.

C. Labrecque; R. Angers; R. Tremblay; D. Dubé

1997-01-01

82

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

Microsoft Academic Search

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

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

2008-01-01

83

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

Federal Register 2010, 2011, 2012, 2013

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

2010-12-08

84

Recycle City  

NSDL National Science Digital Library

Recycle City contains an interactive city map that demonstrates how residents of every section of the city, formerly Dumptown, have recycled, reduced, and reused waste to turn their town around. There is a Dumptown Game with a Control Center to monitor displays while Dumptown changes as waste reduction programs are put in place. Students can create their own Recycle City scavenger hunt or go to the Activities area and see other ways to put Recycle City to use to help protect the environment.

1997-01-01

85

Influence of artificial biological fluid composition on the biocorrosion of potential orthopedic Mg-Ca, AZ31, AZ91 alloys.  

PubMed

The electrochemical behavior of potential orthopedic Mg-Ca, AZ31 and AZ91 alloys was studied in Hank's solution, Dulbecco's Modified Eagle's Medium (DMEM) and serum-containing medium (DMEM adding 10% fetal bovine serum (DMEM+FBS)) over a 7 day immersion period. The biocorrosion of the above three alloys for various immersion time intervals was investigated by linear polarization and electrochemical impedance spectroscopy (EIS). After 7 day immersion, potentiodynamic polarization tests were carried out and the surface morphologies of experimental samples were examined by scanning electron microscopy (SEM) observation complemented by energy-disperse spectrometer (EDS) analysis. It was shown that the corrosion of magnesium alloys was influenced by the composition of the solution. The results indicated that chloride ion could reduce the corrosion resistance and the hydrocarbonate ions could induce rapid surface passivation. The adsorbed amino acid on the experimental magnesium alloys' surface increased their polarization resistance and reduced current densities. The influence of the serum protein on corrosion was found to be associated with the magnesium alloy compositions. A Mg-Ca alloy exhibited an increased corrosion rate in the presence of serum protein. An AZ31 alloy showed an increased corrosion rate in DMEM+FBS in the initial 3 day immersion and the corrosion rate decreased thereafter. An AZ91 alloy, with high Al content, showed a reduced corrosion rate with the addition of FBS into DMEM. PMID:19966381

Gu, X N; Zheng, Y F; Chen, L J

2009-12-01

86

Cities Guide  

NSDL National Science Digital Library

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

2001-01-01

87

A photometric study of the contact binary AZ Virginis  

NASA Astrophysics Data System (ADS)

New light curves and photometric solutions of the contact binary AZ Vir are presented in this paper. The light curves appear to exhibit a typical O'Connell effect, with Maximum I being 0.021 mag (V) and 0.023 mag (B) brighter than Maximum II, respectively. From the observations, six times of minimum light were determined and from the present times of minimum light and those collected from the references, the light elements of the system were improved. The light curves were analyzed by means of the Wilson-Devinney program. The results suggest that AZ Vir is a W-subtype contact binary with a mass ratio of q = 0.623(2). The asymmetry of the light curves is explained by star spot models.

Liu, Q.; Yang, Y.

2007-02-01

88

Creep studies of AZ91D pressure die casting  

Microsoft Academic Search

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

M. Regev; E. Aghion; A. Rosen

1997-01-01

89

Self-assembled monolayers formed on AZ31 Mg alloy  

NASA Astrophysics Data System (ADS)

Self-assembled monolayer (SAM) was successfully adsorbed on the AZ31 Mg alloy surface using oleic acid and stearic acid with various organic solvents, such as acetone, ethanol, and hexane. The surface monolayers were characterized using contact angle measurements, X-ray photoelectron spectroscopy (XPS) and anodic polarization test. It was shown that the higher contact angle and the best anti-corrosion property were obtained with treatment in oleic acid with ethanol solution.

Salman, S. A.; Okido, M.

2012-07-01

90

The Corrosion Protection of Magnesium Alloy AZ31B  

NASA Technical Reports Server (NTRS)

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.

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

1997-01-01

91

Hardening evolution of AZ31B Mg sheet  

Microsoft Academic Search

The monotonic and cyclic mechanical behavior of O-temper AZ31B Mg sheet was measured in large-strain tension\\/compression and simple shear. Metallography, acoustic emission (AE), and texture measurements revealed twinning during in-plane compression and untwinning upon subsequent tension, producing asymmetric yield and hardening evolution. A working model of deformation mechanisms consistent with the results and with the literature was constructed on the

X. Y. Lou; M. Li; R. K. Boger; S. R. Agnew; R. H. Wagoner

2007-01-01

92

Laser Beam Welding of AZ31 Magnesium Alloy with Filler Strip  

Microsoft Academic Search

The 2-mm AZ31 magnesium alloy sheets were laser beam welded using filler metal in the shape of strip. Two kinds of the filler strips, i.e., AZ31 and AZ31 +1.5 wt% Mn were adopted. The effects of the filler strip on the microstructures and tensile properties of the welded joints were investigated. As compared with the autogenous welding process, the welding process

Qiong Chen; Hongge Yan; Jihua Chen; Peilan Zeng; Zhaohui Yu; Bin Su

2010-01-01

93

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

Microsoft Academic Search

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

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

2005-01-01

94

Influence of microstructure on the corrosion of diecast AZ91D  

Microsoft Academic Search

The corrosion of die cast AZ91D was studied and related to its microstructure. For comparison and to more fully understand the behaviour of die cast AZ91D, corrosion studies and microstructural examinations were also carried out using slowly solidified high purity AZ91, Mg-2%Al, Mg-9%Al, low purity magnesium and high purity magnesium. Corrosion was studied in 1 N NaCl at pH 11

Guangling Song; Andrej Atrens; Matthew Dargusch

1998-01-01

95

Linearity and enhanced sensitivity of the Shipley AZ-1350B photoresist.  

PubMed

The properties of the Shipley AZ-1350B positive photoresist used with the Shipley AZ-303A developer were investigated. It was found that the use of AZ-303A developer results in a significant improvement of the sensitivity and the linearity of the photoresist. The unexposed etch rate of the photoresist was 35 A +/- 5 A/sec. Gratings of high efficiency have been successfully fabricated using the above combination of photoresist and developer. PMID:20168765

Livanos, A C; Katzir, A; Shellan, J B; Yariv, A

1977-06-01

96

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

SciTech Connect

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.

RASMUSSEN, J.H.

2000-05-23

97

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

PubMed

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

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

2014-01-30

98

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

Microsoft Academic Search

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.

2000-01-01

99

Historic Cities  

NSDL National Science Digital Library

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

100

Modelling of Superplastic Forming of AZ31 Magnesium Alloy  

SciTech Connect

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

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

2011-01-17

101

Reading a-z: A Complete Online Reading Program  

NSDL National Science Digital Library

A project of LearningPage.com, Reading a-z provides educators with over 150 downloadable guided reading books to help children become more proficient readers. The site also contains over 212 lessons plans, over 500 worksheets, and over 200 flash cards to help teach alphabetic principle, phonemic awareness, and sound/symbol relationships. Although there is an annual subscription fee, viewers currently have free access to 28 sample books, along with their accompanying worksheets and lesson plans. Elementary teachers, home schoolers, and parents may find this site useful.

2002-01-01

102

Atypical Cities  

ERIC Educational Resources Information Center

In this creative challenge, Surrealism and one-point perspective combine to produce images that not only go "beyond the real" but also beyond the ubiquitous "imaginary city" assignment often used to teach one-point perspective. Perhaps the difference is that in the "atypical cities challenge," an understanding of one-point perspective is a means…

DiJulio, Betsy

2011-01-01

103

City Play.  

ERIC Educational Resources Information Center

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

Dargan, Amanda; Zeitlin, Steve

2000-01-01

104

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

Federal Register 2010, 2011, 2012, 2013

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

2013-03-20

105

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

Microsoft Academic Search

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

2001-01-01

106

Corrosion behavior of AZ31 magnesium alloy in simulated acid rain solution  

Microsoft Academic Search

The corrosion mechanism of AZ31 magnesium alloy used as automobile components and the influence of the concentration of Cl? ion in simulated acid rain (SAR) were studied by electrochemical tests and SEM. The results show that pitting corrosion happens around the AlMn phases locating at the grain boundary. The corrosion of AZ31 magnesium alloy in SAR is controlled by the

Feng LIU; Ying-wei SONG; Da-yong SHAN; En-hou HAN

2010-01-01

107

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

Microsoft Academic Search

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

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

2007-01-01

108

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

Microsoft Academic Search

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

2000-01-01

109

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

Microsoft Academic Search

This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for samples obtained from tank 241-AZ-102. The purpose of this sampling event is to obtain information about the characteristics of the contents of 241-AZ-102 required to satisfy the Data Quality Objectives For TWRS Privatization Phase I: Confirm Tank TIS An Appropriate

1999-01-01

110

Spray forming of silicon added AZ91 magnesium alloy and its workability  

Microsoft Academic Search

Si was added to AZ91 Mg alloy to improve the mechanical properties of the AZ91 Mg alloy. Spray forming was employed to refine the primary phases during solidification by means of rapid solidification generated at atomization and droplet flight stages. The process parameters of spray forming were varied to reduce the porosity level and improve the morphology of the billet

C. Y. Chen; Chi Y. A. Tsao

2004-01-01

111

Histone Variant H2A.Z Functions in Sister Chromatid Cohesion in Saccharomyces cerevisiae  

PubMed Central

H2A.Z is a highly conserved variant of histone H2A with well-characterized roles in transcriptional regulation. We previously reported that H2A.Z and Mcd1, a subunit of the cohesin complex, regulate the establishment of transcriptional silencing at telomeres in Saccharomyces cerevisiae and that H2A.Z broadly dissociated from chromatin during the anaphase-to-telophase transition, coincident with the dissociation of Mcd1 from chromosomes and dissolution of cohesion. In this study, we show that depletion of H2A.Z causes precocious loss of sister chromatid cohesion in yeast without loss of Mcd1 from chromosomes. H2A.Z is deposited into chromatin by the SWR1 complex and is subject to acetylation of its four N-terminal tail lysine residues by the NuA4 and SAGA histone acetyltransferase complexes. We found that cells compromised for function of the SWR1 complex were defective in cohesion, as were cells expressing a form of H2A.Z not subject to acetylation. Finally, inactivation of H2A.Z in metaphase-blocked cells led immediately to cohesion defects, suggesting a direct role for H2A.Z in the maintenance of sister chromatid cohesion.

Sharma, Upasna; Stefanova, Dessislava

2013-01-01

112

Microstructure and rolling capability of modified AZ31-Ce-Gd alloys  

SciTech Connect

AZ31-Ce-Gd alloys were studied and the influence of cerium (Ce) and gadolinium (Gd) on the microstructure and rolling capability of AZ31 alloy was investigated. The results indicated that the grains of AZ31 alloy were refined with Ce and Gd addition. Ce and Gd addition resulted in the formation of Al{sub 4}Ce, Al{sub 2}Gd and Mg{sub 3}Gd. After homogenization and rolling, the Al{sub 4}Ce, Al{sub 2}Gd and Mg{sub 3}Gd still existed. The rolling capability of AZ31 alloy was improved obviously with Ce and Gd addition. However, once Gd content increased to a certain value, the rolling capability of the modified alloy declined but still better than that of AZ31 alloy.

Li Wenping [Key Laboratory of Automobile Materials of Ministry of Education and Department of Materials Science and Engineering, Nanling Campus of Jilin University, No.5988 Renmin Street, Changchun 130025 (China); Zhou Hong, E-mail: asnacml@163.com [Key Laboratory of Automobile Materials of Ministry of Education and Department of Materials Science and Engineering, Nanling Campus of Jilin University, No.5988 Renmin Street, Changchun 130025 (China); Lin Pengyu; Zhao Shizhe [Key Laboratory of Automobile Materials of Ministry of Education and Department of Materials Science and Engineering, Nanling Campus of Jilin University, No.5988 Renmin Street, Changchun 130025 (China)

2009-11-15

113

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.

1997-01-01

114

Open City  

NSDL National Science Digital Library

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

115

Invincible Cities  

NSDL National Science Digital Library

Throughout history, cities have risen and fallen from prominence, and in recent times more attention has been paid to why this ebb and flow persists across the centuries. Documenting this process has increasingly been the province of historians, archaeologists, city planners, sociologists, and of course, photographers. Many photographers have been very interested in the world of post-industrial urban decay, and Camilo Jose Vergara is one of the best. With financial support from the Ford Foundation, this website brings together VergaraâÂÂs photographic record of the cities of Camden, New Jersey and Richmond, California in exquisite geographic and visual detail. First-time visitors will want to read through the introduction to the project offered by Vergara, and then perhaps click on the question mark on the homepage for a brief primer on how to use the user interface for each city. At that point, visitors shouldnâÂÂt be afraid to look over both cities, as they can zoom in and out around a number of interesting locales, including abandoned factories, old piers, and gated communities. Short of wandering through these cities in a peripatetic fashion, this website serves as an interesting introduction to some overlooked aspects of urbanity.

Vergara, Camilo J.

2006-01-01

116

Activation of p21 by HDAC Inhibitors Requires Acetylation of H2A.Z  

PubMed Central

Differential positioning of the histone variant H2A.Z in a p53 dependent manner was shown to regulate p21 transcription. Whether H2A.Z is involved in p21 activity in the absence of p53 is not known. The p21 gene is repressed in estrogen receptor (ER) negative cell lines that are p53?/? and hormone independent for their growth. Here we demonstrate that class I and II pan Histone deacetylase inhibitors (HDACi) induce p21 transcription and reduce cell proliferation of MDA-MB231, an ER?-negative mammary tumor cell line, in a H2A.Z dependent manner. H2A.Z is associated with the transcription start site (TSS) of the repressed p21 gene. Depleting H2A.Z did not lead to transcription of p21 but annihilated the stimulating effect of HDACi on this gene. Acetylation of H2A.Z but not of H3K9 at the p21 promoter correlated with p21 activation. We further show that HDACi treatment reduced the presence of the p400 chromatin remodeler at the p21 TSS. We propose a model in which association of p400 negatively affects p21 transcription by interfering with acetylation of H2A.Z.

Kocanova, Silvia; Moutahir, Fatima; Bystricky, Kerstin

2013-01-01

117

Mineral Mapping Using AVIRIS Data at Ray Mine, AZ  

NASA Technical Reports Server (NTRS)

Imaging Spectroscopy enables the identification and mapping of surface mineralogy over large areas. This study focused on assessing the utility of Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data for environmental impact analysis over the Environmental Protection Agency's (EPA) high priority Superfund site Ray Mine, AZ. Using the Spectral Angle Mapper (SAM) algorithm to analyze AVIRIS data makes it possible to map surface materials that are indicative of acid generating minerals. The improved performance of the AVIRIS sensor since 1996 provides data with sufficient signal to noise ratio to characterize up to 8 image endmembers. Specifically we employed SAM to map minerals associated with mine generated acid waste, namely jarositc, goethite, and hematite, in the presence of a complex mineralogical background.

McCubbin, Ian; Lang, Harold; Green, Robert O.; Roberts, Dar

1998-01-01

118

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).

119

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

Microsoft Academic Search

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

L. Shepeleva; M. Bamberger

2006-01-01

120

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

SciTech Connect

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.

BRIGGS, S.R.

2000-02-25

121

City 2020+  

NASA Astrophysics Data System (ADS)

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

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

2010-09-01

122

Mexico City  

... year. In winter, air quality can worsen significantly when thermal inversions keep polluted air masses close to the surface. ... color views acquired by MISR's 70-degree forward-viewing camera on April 9 and December 5, 2001, respectively. Mexico City can be ...

2013-04-18

123

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

National Technical Information Service (NTIS)

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. T...

A. M. Templeton

2000-01-01

124

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

Federal Register 2010, 2011, 2012, 2013

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

2010-03-12

125

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

SciTech Connect

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.

Robinson, R.S.

1996-10-30

126

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

Federal Register 2010, 2011, 2012, 2013

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

2011-10-17

127

75 FR 35122 - Approval of Noise Compatibility Program for Buckeye Municipal Airport, Town of Buckeye, AZ  

Federal Register 2010, 2011, 2012, 2013

...Compatibility Program for Buckeye Municipal Airport, Town of Buckeye, AZ AGENCY: Federal...the FAA approved the Buckeye Municipal Airport noise compatibility program. All of the...Compatibility Program for Buckeye Municipal Airport is May 13, 2010. FOR FURTHER...

2010-06-21

128

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

Federal Register 2010, 2011, 2012, 2013

...Basis and Purpose The Lake Havasu Divers Association...40 divers cleaning the river bottom in Lake Havasu. The Coast Guard...Copper Canyon Clean Up, Lake Havasu, AZ. (a) Location...from the surface to the river bottom, within 500...

2010-05-11

129

77 FR 2241 - Radio Broadcasting Services; Ehrenberg, First Mesa, Kachina Village, Wickenburg, and Williams, AZ...  

Federal Register 2010, 2011, 2012, 2013

...RM-11517, RM-11518; DA 11-2058] Radio Broadcasting Services; Ehrenberg, First...Williams, AZ; and Application of Univision Radio License Corporation, KHOV-FM, Wickenburg...proposal, RM-11517, filed by Rocket Radio, Inc., proposes the allotment of...

2012-01-17

130

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

SciTech Connect

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.

ANDREWS, J.E.

2000-03-28

131

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

Microsoft Academic Search

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.

1996-01-01

132

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

Federal Register 2010, 2011, 2012, 2013

...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....

2012-05-01

133

76 FR 14115 - Arizona Disaster #AZ-00015 Declaration of Economic Injury  

Federal Register 2010, 2011, 2012, 2013

... AZ-00015 Declaration of Economic Injury AGENCY: U.S. Small Business Administration...This is an amendment of the Economic Injury Disaster Loan (EIDL) declaration for...INFORMATION: The notice of an Economic Injury Disaster Declaration for the State...

2011-03-15

134

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

PubMed Central

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

Sonego, Paolo; Engelen, Kristof; Pertot, Ilaria

2014-01-01

135

78 FR 18269 - Proposed Modification of Class E Airspace; Clifton/Morenci, AZ  

Federal Register 2010, 2011, 2012, 2013

...AZ to accommodate aircraft using Area Navigation (RNAV) Global Positioning...and management of aircraft operations at the...ensure the safety of aircraft and the efficient...Incorporation by reference, Navigation (air). The...

2013-03-26

136

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

Federal Register 2010, 2011, 2012, 2013

...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...

2011-12-16

137

76 FR 62144 - Environmental Impact Statement for Implementation of Passenger Rail Service Between Tucson, AZ...  

Federal Register 2010, 2011, 2012, 2013

...Statement for Implementation of Passenger Rail Service Between Tucson, AZ and Phoenix...to study the implementation of passenger rail service between Tucson, Arizona and Phoenix...build alternatives that provide intercity rail service. Identifying the...

2011-10-06

138

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

SciTech Connect

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

STENKAMP, D.M.

2000-04-03

139

Forming limit of textured AZ31B magnesium alloy sheet at different temperatures  

Microsoft Academic Search

Repeated unidirectional bending (RUB) was carried out to improve the texture of commercial AZ31B magnesium alloy sheets. All specimens were prepared in the rolling direction. The forming limit diagrams (FLDs) of AZ31B magnesium alloy sheet were determined experimentally by conducting stretch-forming tests at room temperature, 100, 200 and 300 °C. Compared with the as-received sheet, the lowest limited strain of

Guang-sheng HUANG; Hua ZHANG; Xiao-yun GAO; Bo SONG; Lei ZHANG

2011-01-01

140

Acceptance Test Report for the 241-AZ-101 Ultrasonic Interface Level Analyzer  

SciTech Connect

This document comprises the Acceptance Test Report for the 241-AZ-101 Ultrasonic Interface Level Analyzer. This document presents the results of Acceptance Testing of the 241-AZ-101 Ultrasonic Interface Level Analyzers (URSILLAs). Testing of the URSILLAs was performed in accordance with ATP-260-001, ''URSILLA Pre-installation Acceptance Test Procedure''. The objective of the testing was to verify that all equipment and components function in accordance with design specifications and original equipment manufacturer's specifications.

ANDREWS, J.E.

2000-01-27

141

Formation and retention of local melted films in AZ91 friction stir spot welds  

Microsoft Academic Search

The formation of local melted films during friction stir spot welding of as-cast AZ91D and thixomolded AZ91 material is investigated.\\u000a The average temperatures close to the tip of the rotating pin vary from 438 to 454 ?C during the dwell period in friction\\u000a stir spot welding. These measured temperature values are higher than the melting temperature of ?-Mg + Mg17Al12 eutectic (437 ?C). It

Peter Su; Adrian Gerlich; Motomichi Yamamoto; Thomas H. North

2007-01-01

142

Hook formation and mechanical properties in AZ31 friction stir spot welds  

Microsoft Academic Search

Hook formation and the failure load properties of AZ31 friction stir spot welds are investigated in friction stir spot welds made between wrought and heat-treated AZ31 sheets having widely different average grain sizes.Tool shoulder penetration into the surface of the upper sheet and pin penetration into the lower sheet during the dwell period provides the driving force for the displacement

Y. H. Yin; N. Sun; T. H. North; S. S. Hu

2010-01-01

143

Feasibility of joining AZ31B magnesium metal matrix composite by friction welding  

Microsoft Academic Search

The present study investigates the feasibility of joining AZ31B magnesium nanocomposites by rotational friction welding. The AZ31B magnesium metal matrix composite, which was reinforced with alumina (Al2O3, average particle size of 50nm) and calcium (Ca), was produced by a hybrid casting process and hot extruded at 350°C. Joining processes were done by varying the friction welding parameters. The integrity of

M. Srinivasan; C. Loganathan; V. Balasubramanian; Q. B. Nguyen; M. Gupta; R. Narayanasamy

2011-01-01

144

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

Microsoft Academic Search

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

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

2010-01-01

145

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

Microsoft Academic Search

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

1999-01-01

146

Histone H2A.Z Regulates Transcription and Is Partially Redundant with Nucleosome Remodeling Complexes  

Microsoft Academic Search

Nucleosomes impose a block to transcription that can be overcome in vivo by remodeling complexes such as SNF\\/SWI and histone modification complexes such as SAGA. Mutations in the major core histones relieve transcriptional repression and bypass the requirement for SNF\\/SWI and SAGA. We have found that the variant histone H2A.Z regulates gene transcription, and deletion of the gene encoding H2A.Z

Maria Soledad Santisteban; Tatyana Kalashnikova; M. Mitchell Smith

2000-01-01

147

Series expansions for the incomplete Lipschitz-Hankel integral Je0(a,z)  

Microsoft Academic Search

Bessel series expansions are derived for the incomplete Lipschitz-Hankel integral Je0(a,z). These expansions are obtained by using contour integration techniques to evaluate the inverse Laplace transform representation for Je0(a,z). It is shown that one of the expansions can be used as a convergent series expansion for one definition of the branch cut and as an asymptotic expansion if the branch

Mehdi M. Mechaik; Steven L. Dvorak

1995-01-01

148

Series expansions for the incomplete Lipschitz-Hankel integral Ye0(a,z)  

Microsoft Academic Search

Three series expansions are derived for the incomplete Lipschitz-Hankel integral Ye0(a,z) for complex-valued a and z. Two novel expansions are obtained by using contour integration techniques to evaluate the inverse Laplace transform representation for Ye0(a,z). A third expansion is obtained by replacing the Neumann function by its Neumann series representation and integrating the resulting terms. An algorithm is outlined which

Mehdi M. Mechaik; Steven L. Dvorak

1996-01-01

149

Hot rolling characteristics of spray-formed AZ91 magnesium alloy  

Microsoft Academic Search

AZ91 magnesium alloy was prepared by spray forming. The spray-deposited alloy was subsequently hot-rolled with a 80% reduction at 350 °C. The microstructural features of the as-spray-deposited and hot-rolled alloy were examined by optical microscopy, scanning electron microscopy and X-ray diffractometry. The results show that the spray-formed AZ91 magnesium alloy has, compared with the as-cast ingot, a finer microstructure with

Xiao-feng WANG; Jiu-zhou ZHAO; Jie HE; Zhuang-qi HU

2007-01-01

150

Best Cities to Start and Grow a Company in Now  

NSDL National Science Digital Library

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

151

Lysobacter capsici AZ78 can be combined with copper to effectively control Plasmopara viticola on grapevine.  

PubMed

The bacterial genus Lysobacter represents a still underdeveloped source of biocontrol agents able to protect plants against pathogenic oomycetes. In this work the L. capsici strain AZ78 was evaluated with regard to the biological control of Plasmopara viticola, the causal agent of grapevine downy mildew. L. capsici AZ78 is able to resist copper ions and its resistance to this metal is probably due to the presence of genes coding for copper oxidase (copA) and copper exporting PIB-type ATPases (ctpA). The presence of both genes was also detected in other members of the Lysobacter genus. Resistance to copper allowed L. capsici AZ78 to be combined with a low-dose of a copper-based fungicide, leading to more effective control of grapevine downy mildew. Notably, prophylactic application of L. capsici AZ78 alone to grapevine leaves reduced downy mildew disease to the same degree as a copper-based fungicide. Furthermore, L. capsici AZ78 persists in the phyllosphere of grapevine plants and tolerates environmental stresses such as starvation, freezing, mild heat shock and UV light irradiation. These traits suggest that L. capsici AZ78 could be a suitable candidate for developing a new biofungicide to be used in combination with copper to control grapevine downy mildew. PMID:24140153

Puopolo, Gerardo; Giovannini, Oscar; Pertot, Ilaria

2014-01-01

152

Resistance Spot Welded AZ31 Magnesium Alloys, Part II: Effects of Welding Current on Microstructure and Mechanical Properties  

NASA Astrophysics Data System (ADS)

Resistance spot welding of AZ31 magnesium alloys from different suppliers, AZ31-SA (from supplier A) and AZ31-SB (from supplier B), was studied and compared in this article. The mechanical properties and microstructures have been studied of welds made with a range of welding currents. For both groups of welds, the tension-shear fracture load ( F C) and fracture toughness ( K C) increased with the increase in welding current. The F C and K C of AZ31-SA welds were larger than those of AZ31-SB welds. The fracture surfaces of AZ31-SB welds were relatively flatter than those of AZ31-SA. Microstructural examination via optical microscope demonstrated that almost all weld nuggets comprised two different zones, the columnar dendritic zone (CDZ), which grew epitaxially from the fusion boundary, and the equiaxed dendritic zone (EDZ), which formed in the center of the nugget. The nature and extent of the CDZ seemed to be critical to the strength and toughness of spot welds because of its position adjacent to the inherent external circular crack-like notch of spot welds and the stress concentration in this region. The width and microstructure of the CDZ were different between AZ31-SA and AZ31-SB. The AZ31-SA alloy produced finer and shorter columnar dendrites, whereas the AZ31-SB alloy produced coarser and wider columnar dendrites. The width of the CDZ close to the notch decreased with the increase of current. The CDZ disappeared when the current was higher than a critical value, which was about 24 kA for AZ31-SA and 28 kA for AZ31-SB. The microhardness of the two base materials was the same, but within the CDZ and EDZ, the hardness was greater in AZ31-SA than AZ31-SB welds. It is believed that the different microstructures of spot welds between AZ31-SA and AZ31-SB resulted in different mechanical properties; in particular, K C increased with the welding current because of the improved columnar-to-equiaxed transition.

Liu, L.; Xiao, L.; Feng, J. C.; Tian, Y. H.; Zhou, S. Q.; Zhou, Y.

2010-10-01

153

-dimensional Symmetry Catalysts for A-Z Gas Loading Fusion  

NASA Astrophysics Data System (ADS)

An epitaxial mating of a metal layer to a chemically stable ionic crystal minimizes system energy for cold fusion based on Bloch function symmetry and using gas loading and nm-Pd at a favored interface.[1] To achieve epitaxy second and third metal layers need to have imperfections. One thinks of the stable ionic crystal as a template and the nano-Pd solid as a malleable lattice. The interior volume of the nano-Pd solid has a face-centered cubic structure. ZrO2 was the template ionic crystal used in A-Z gas loading studies at elevated T in (2005). A template crystal using the sapphire crystal equivalent of a double-layer graphene crystal is suggested. Impurity Rh and Ru are suggested as impurity atoms in the nano-metal (as in gem-quality Zircon) and a amall amount of interstitial H in addition to dominant D as involved in diffusion. Ref. [1] "Interface Modeling of Cold Fusion," Talbot A. Chubb, Proc. ICCF14, Book 2, pp 534-539 (2008).

Chubb, Talbot

2011-03-01

154

Fine particulate chemical composition and light extinction at Meadview, AZ  

SciTech Connect

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

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

2006-12-15

155

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

NASA Astrophysics Data System (ADS)

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.

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

2014-03-01

156

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

Microsoft Academic Search

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

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

2006-01-01

157

Kinetic City  

NSDL National Science Digital Library

Kinetic City is an after-school standards-based science program in which kids complete activities in conjunction with a dynamic website. It includes science experiments, games, activities, challenges and more. It provides kids in grades three through five a fun, entertaining way to learn standards-based science. It is the ideal combination of technology and hands-on collaboration. A free log-in is required for some of the content on the site. An additional section for educators or parents is featured. This provides guidance on how to best implement some of the resources. Overall, this is a nice collection for more general resources on these topics.

2009-07-02

158

Subaru Telescope improved pointing accuracy in open-loop and Az rail flatness  

NASA Astrophysics Data System (ADS)

The Subaru telescope had its astronomical first light in January 1999 and has been stably operated since the common use started in December 2000. The telescope is mounted on an alt-azimuth structure. The structure of 550 tons is supported by six hydrostatic oil pads which lift the structure by 50 microns. The azimuth (Az) and elevation (El) axes are driven by direct-drive linear motors, ensuring very smooth pointing and tracking operations. The Az rail consists of eight circular arc pieces. They were installed in January 1997 with a peak-to-peak level of within 0.1mm. However at a later time, vertical undulations of the Az rail were found to be more than 0.2 mm peak-to-peak at some locations where the telescope structure in the rest position applies load. Open-loop tracking accuracy of the telescope, which was about 2 arcsec RMS on the sky, was found to be due to the undulations of the Az rail. We made a table to correct telescope pointings due to the undulations. It has made open-loop tracking accuracy better than 0.2arcsec RMS. Since then, we have been monitoring the flatness of the Az rail. So far the undulations have not changed.

Negishi, Satoru; Kanzawa, Tomio; Tomono, Daigo; Usuda, Tomonori; Ohshima, Norio; Namikawa, Kazuhito; Ogasawara, Takeji; Itoh, Noboru

2006-07-01

159

Expanding cities, shrinking cities, sustainable cities: challenges, opportunities and examples  

Microsoft Academic Search

Over the last decades, experts have been studying with growing concern statistics and demographic trends that show in many cities the urban population appears to be climbing up to astonishing numbers all over the world. Mega-Cities like Tokyo, Mexico City and Seoul are developing and nobody appears to be able to control their growth, nor to handle their impact on

DIETER D GENSKE; ARIANE RUFF

160

Learning Cities as Healthy Green Cities: Building Sustainable Opportunity Cities  

ERIC Educational Resources Information Center

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

Kearns, Peter

2012-01-01

161

Sprawl City  

NSDL National Science Digital Library

Created by environmental authors Leon Kolankiewicz and Roy Beck, Sprawl City is a site dedicated to informing and assisting the general public about the issues of sprawl and rural land lost in the United States. With oversight from a variety of academic and practicing planners, the site contains a host of information about the growing rate of sprawl among urbanized and urbanizing areas across the country. Most helpful are a series of studies by Kolankiewicz and Beck investigating sprawl in several different states and regions, including California, Florida, Minnesota, and the Chesapeake Bay watershed. Along with all of their reports and studies, a section of definitions offers a more concrete explanation of how "sprawl" and other terms are technically defined.

2000-01-01

162

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

SciTech Connect

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.

TEMPLETON, A.M.

1999-07-08

163

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

SciTech Connect

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.

TEMPLETON, A.M.

2000-04-10

164

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

SciTech Connect

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.

TEMPLETON, A.M.

2000-01-31

165

Modeling in vivo corrosion of AZ31 as temporary biodegradable implants. Experimental validation in rats.  

PubMed

In this paper, two complementary approaches, mathematical modeling and experimental results are combined to identify variables that affect the in vivo biodegradation of magnesium implants. The in vivo corrosion behavior of AZ31 alloy proposed for temporary applications as fixation of bone fractures has been modeled solving the Laplace equation by finite element method (FEM). Bar-shaped AZ31 implants of 1mm diameter and 20mm length were inserted in Wistar rat femurs with and without a fracture. The presence of gas around AZ31 implants inside the femurs has been detected in situ at the epiphysis and in fractured areas by computerized tomography (CT). Examining some in vivo conditions, the model confirms that magnesium-alloy devices have different biodegradation behavior, depending on the thickness of electrolyte at the implantation site and can be used for predicting the biodegradation behavior. PMID:24907745

Montoya, R; Iglesias, C; Escudero, M L; García-Alonso, M C

2014-08-01

166

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

SciTech Connect

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.

TEMPLETON, A.M.

2000-03-06

167

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

PubMed Central

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.

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

2012-01-01

168

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

Microsoft Academic Search

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.

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

2003-01-01

169

Formability of Ultrafine-Grain Mg Alloy AZ31B at Warm Temperatures  

Microsoft Academic Search

Warm formability of ultrafine-grain (UFG) AZ31B Mg alloy in the range of 150 °C to 311 °C is investigated. Refinement of grain\\u000a size significantly improves the formability primarily through increasing strain rate sensitivity of flow stress and increasing\\u000a diffuse quasi-stable flow, as compared with the coarse-grain AZ31B alloy. Strain rate sensitivity increases with increasing\\u000a temperatures, and seems to be connected with dynamic

Q. Yang; A. K. Ghosh

2008-01-01

170

Brain H2A.Z: the long and the short  

PubMed Central

The role of histone variants and their specific post-translational modifications (PTMs) in the epigenetic regulation of gene expression is still poorly understood. A paper published by Simonet and colleagues in Epigenetics and Chromatin describes a new H2A.Z subtype that is specific for brain and pituitary in the carp and provides additional information about the functional epigenetic complexity of the PTMs associated with histone H2A.Z. See research article: http://www.epigeneticsandchromatin.com/content/6/1/22

2013-01-01

171

Anp32e, a higher eukaryotic histone chaperone directs preferential recognition for H2A.Z  

PubMed Central

H2A.Z is a highly conserved histone variant in all species. The chromatin deposition of H2A.Z is specifically catalyzed by the yeast chromatin remodeling complex SWR1 and its mammalian counterpart SRCAP. However, the mechanism by which H2A.Z is preferentially recognized by non-histone proteins remains elusive. Here we identified Anp32e, a novel higher eukaryote-specific histone chaperone for H2A.Z. Anp32e preferentially associates with H2A.Z-H2B dimers rather than H2A-H2B dimers in vitro and in vivo and dissociates non-nucleosomal aggregates formed by DNA and H2A-H2B. We determined the crystal structure of the Anp32e chaperone domain (186-232) in complex with the H2A.Z-H2B dimer. In this structure, the region containing Anp32e residues 214-224, which is absent in other Anp32 family proteins, specifically interacts with the extended H2A.Z ?C helix, which exhibits an unexpected conformational change. Genome-wide profiling of Anp32e revealed a remarkable co-occupancy between Anp32e and H2A.Z. Cells overexpressing Anp32e displayed a strong global H2A.Z loss at the +1 nucleosomes, whereas cells depleted of Anp32e displayed a moderate global H2A.Z increase at the +1 nucleosomes. This suggests that Anp32e may help to resolve the non-nucleosomal H2A.Z aggregates and also facilitate the removal of H2A.Z at the +1 nucleosomes, and the latter may help RNA polymerase II to pass the first nucleosomal barrier.

Mao, Zhuo; Pan, Lu; Wang, Weixiang; Sun, Jian; Shan, Shan; Dong, Qiang; Liang, Xiaoping; Dai, Linchang; Ding, Xiaojun; Chen, She; Zhang, Zhuqiang; Zhu, Bing; Zhou, Zheng

2014-01-01

172

Anp32e, a higher eukaryotic histone chaperone directs preferential recognition for H2A.Z.  

PubMed

H2A.Z is a highly conserved histone variant in all species. The chromatin deposition of H2A.Z is specifically catalyzed by the yeast chromatin remodeling complex SWR1 and its mammalian counterpart SRCAP. However, the mechanism by which H2A.Z is preferentially recognized by non-histone proteins remains elusive. Here we identified Anp32e, a novel higher eukaryote-specific histone chaperone for H2A.Z. Anp32e preferentially associates with H2A.Z-H2B dimers rather than H2A-H2B dimers in vitro and in vivo and dissociates non-nucleosomal aggregates formed by DNA and H2A-H2B. We determined the crystal structure of the Anp32e chaperone domain (186-232) in complex with the H2A.Z-H2B dimer. In this structure, the region containing Anp32e residues 214-224, which is absent in other Anp32 family proteins, specifically interacts with the extended H2A.Z ?C helix, which exhibits an unexpected conformational change. Genome-wide profiling of Anp32e revealed a remarkable co-occupancy between Anp32e and H2A.Z. Cells overexpressing Anp32e displayed a strong global H2A.Z loss at the +1 nucleosomes, whereas cells depleted of Anp32e displayed a moderate global H2A.Z increase at the +1 nucleosomes. This suggests that Anp32e may help to resolve the non-nucleosomal H2A.Z aggregates and also facilitate the removal of H2A.Z at the +1 nucleosomes, and the latter may help RNA polymerase II to pass the first nucleosomal barrier. PMID:24613878

Mao, Zhuo; Pan, Lu; Wang, Weixiang; Sun, Jian; Shan, Shan; Dong, Qiang; Liang, Xiaoping; Dai, Linchang; Ding, Xiaojun; Chen, She; Zhang, Zhuqiang; Zhu, Bing; Zhou, Zheng

2014-04-01

173

Great Zoom out of the Grand Canyon, AZ  

NSDL National Science Digital Library

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.

Shirah, Greg; Mitchell, Horace; Newcombe, Marte; Williams, Darrel

2003-01-14

174

Expression of P. falciparum var Genes Involves Exchange of the Histone Variant H2A.Z at the Promoter  

PubMed Central

Plasmodium falciparum employs antigenic variation to evade the human immune response by switching the expression of different variant surface antigens encoded by the var gene family. Epigenetic mechanisms including histone modifications and sub-nuclear compartmentalization contribute to transcriptional regulation in the malaria parasite, in particular to control antigenic variation. Another mechanism of epigenetic control is the exchange of canonical histones with alternative variants to generate functionally specialized chromatin domains. Here we demonstrate that the alternative histone PfH2A.Z is associated with the epigenetic regulation of var genes. In many eukaryotic organisms the histone variant H2A.Z mediates an open chromatin structure at promoters and facilitates diverse levels of regulation, including transcriptional activation. Throughout the asexual, intraerythrocytic lifecycle of P. falciparum we found that the P. falciparum ortholog of H2A.Z (PfH2A.Z) colocalizes with histone modifications that are characteristic of transcriptionally-permissive euchromatin, but not with markers of heterochromatin. Consistent with this finding, antibodies to PfH2A.Z co-precipitate the permissive modification H3K4me3. By chromatin-immunoprecipitation we show that PfH2A.Z is enriched in nucleosomes around the transcription start site (TSS) in both transcriptionally active and silent stage-specific genes. In var genes, however, PfH2A.Z is enriched at the TSS only during active transcription in ring stage parasites. Thus, in contrast to other genes, temporal var gene regulation involves histone variant exchange at promoter nucleosomes. Sir2 histone deacetylases are important for var gene silencing and their yeast ortholog antagonises H2A.Z function in subtelomeric yeast genes. In immature P. falciparum parasites lacking Sir2A or Sir2B high var transcription levels correlate with enrichment of PfH2A.Z at the TSS. As Sir2A knock out parasites mature the var genes are silenced, but PfH2A.Z remains enriched at the TSS of var genes; in contrast, PfH2A.Z is lost from the TSS of de-repressed var genes in mature Sir2B knock out parasites. This result indicates that PfH2A.Z occupancy at the active var promoter is antagonized by PfSir2A during the intraerythrocytic life cycle. We conclude that PfH2A.Z contributes to the nucleosome architecture at promoters and is regulated dynamically in active var genes.

Petter, Michaela; Lee, Chin Chin; Byrne, Timothy J.; Boysen, Katja E.; Volz, Jennifer; Ralph, Stuart A.; Cowman, Alan F.; Brown, Graham V.; Duffy, Michael F.

2011-01-01

175

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

Microsoft Academic Search

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

P. Cavaliere; P. P. De Marco

2007-01-01

176

Creep of a thixoformed and heat treated AZ91 Mg-Al-Zn alloy  

SciTech Connect

The most frequently used cast magnesium alloy is AZ91, which contains 9% Al, 1% Zn and some Mn. Recently some studies have investigated the creep response of AZ91 ingots, pressure-die-casting and thixoformed specimens; die-cast and thixoformed alloys frequently show a similar microstructure, with equiaxed grains of {alpha} phase (solid solution of Al and Zn in Mg) and a brittle secondary phase, Mg{sub 17}Al{sub 12} ({beta} phase), on grain boundaries. The die-cast alloy has a very fine grain size (15 {micro}m) and a higher concentration of Mg{sub 17}Al{sub 12} than ingots; the thixoformed alloy exhibits large {alpha} phase globules of around 100 {micro}m and small {alpha}-particles of few microns in the eutectic region. The creep response of the die-cast and thixoformed alloys was found to be substantially equivalent, the creep strength of the die-cast material being one order of magnitude lower than that of the ingot. Thixoforming is one of the new processes that can be used to produce Magnesium alloy components for automotive applications. However, the typical structure of the thixoformed AZ91 exhibits a modest ductility, a property that can be substantially improved by subsequent solution treatment aimed at dissolving the brittle {beta} phase. The present study was undertaken to investigate the high-temperature response of thixoformed and solution treated AZ91.

Spigarelli, S.

2000-01-31

177

Complete Genome Sequence of the Model Rhizosphere Strain Azospirillum brasilense Az39, Successfully Applied in Agriculture  

PubMed Central

We present the complete genome sequence of Azospirillum brasilense Az39, isolated from wheat roots in the central region of Argentina and used as inoculant in extensive and intensive agriculture during the last four decades. The genome consists of 7.39 Mb, distributed in six replicons: one chromosome, three chromids, and two plasmids.

Rivera, Diego; Revale, Santiago; Molina, Romina; Gualpa, Jose; Puente, Mariana; Maroniche, Guillermo; Paris, Gaston; Baker, David; Clavijo, Bernardo; McLay, Kirsten; Spaepen, Stijn; Perticari, Alejandro; Vazquez, Martin; Wisniewski-Dye, Florence; Watkins, Chris; Martinez-Abarca, Francisco; Vanderleyden, Jos

2014-01-01

178

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

NASA Technical Reports Server (NTRS)

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

Lang, H.; Baloga, S.

1999-01-01

179

Mechanical And Microstructural Aspects Of High Temperature Formability Of AZ31 Sheets  

Microsoft Academic Search

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

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

2007-01-01

180

78 FR 40381 - Establishment of Class E Airspace; Grand Canyon, AZ  

Federal Register 2010, 2011, 2012, 2013

...under control of Los Angeles Air Route Traffic Control Center (ARTCC). This improves the safety and management of IFR operations...AZ, to accommodate IFR aircraft under control of Los Angeles ARTCC by vectoring aircraft from en route airspace to terminal...

2013-07-05

181

?Np63? represses anti-proliferative genes via H2A.Z deposition  

PubMed Central

?Np63? is a member of the p53 family of transcription factors that functions as an oncogene in squamous cell carcinomas (SCCs). Because ?Np63? and p53 bind virtually identical DNA sequence motifs, it has been proposed that ?Np63? functions as a dominant-negative inhibitor of p53 to promote proliferation and block apoptosis. However, most SCCs concurrently overexpress ?Np63? and inactivate p53, suggesting the autonomous action of these oncogenic events. Here we report the discovery of a novel mechanism of transcriptional repression by ?Np63? that reconciles these observations. We found that although both proteins bind the same genomic sites, they regulate largely nonoverlapping gene sets. Upon activation, p53 binds all enhancers regardless of ?Np63? status but fails to transactivate genes repressed by ?Np63?. We found that ?Np63? associates with the SRCAP chromatin regulatory complex involved in H2A/H2A.Z exchange and mediates H2A.Z deposition at its target loci. Interestingly, knockdown of SRCAP subunits or H2A.Z leads to specific induction of ?Np63?-repressed genes. We identified SAMD9L as a key anti-proliferative gene repressed by ?Np63? and H2A.Z whose depletion suffices to reverse the arrest phenotype caused by ?Np63? knockdown. Collectively, these results illuminate a molecular pathway contributing to the autonomous oncogenic effects of ?Np63?.

Gallant-Behm, Corrie L.; Ramsey, Matthew R.; Bensard, Claire L.; Nojek, Ignacio; Tran, Jack; Liu, Minghua; Ellisen, Leif W.; Espinosa, Joaquin M.

2012-01-01

182

76 FR 42155 - Arizona Disaster #AZ-00017 Declaration of Economic Injury  

Federal Register 2010, 2011, 2012, 2013

... AZ-00017 Declaration of Economic Injury AGENCY: U.S. Small Business Administration...SUMMARY: This is a notice of an Economic Injury Disaster Loan (EIDL) declaration for...declaration, applications for economic injury disaster loans may be filed at the...

2011-07-18

183

76 FR 8801 - Arizona Disaster #AZ-00015 Declaration of Economic Injury  

Federal Register 2010, 2011, 2012, 2013

... AZ-00015 Declaration of Economic Injury AGENCY: U.S. Small Business Administration...SUMMARY: This is a notice of an Economic Injury Disaster Loan (EIDL) declaration for...declaration, applications for economic injury disaster loans may be filed at the...

2011-02-15

184

Corrosion resistance of aged die cast magnesium alloy AZ91D  

Microsoft Academic Search

The corrosion behaviour of die cast magnesium alloy AZ91D aged at 160°C was investigated. The corrosion rate of the alloy decreases with ageing time in the initial stages and then increases again at ageing times greater than 45h. The dependence of the corrosion rate on ageing time can be related to the changes in microstructure and local composition during ageing.

Guangling Song; Amanda L Bowles; David H StJohn

2004-01-01

185

Interim Report for Crucible-Scale Active Vitrification Testing Envelope B (AZ-102)  

SciTech Connect

The purposes of this work were to demonstrate the evaporation of AZ-102 supernate, demonstrate the vitrification of the evaporated concentrate in a crucible melt, and to demonstrate acceptance of the resulting glass by analysis (chemical and radionuclides) and durability testing.

Crawford, C.L.

2002-08-23

186

Radioisotope inventory of T101AZ thermocouple tree from riser 13D  

SciTech Connect

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

Kessler, S.F., Westinghouse Hanford

1996-06-12

187

Microstructure and properties of magnesium AZ31B–aluminum 7075 explosively welded composite plate  

Microsoft Academic Search

A composite plate of Mg alloy (AZ31B) and an Al alloy (7075) was fabricated by explosive welding. The microstructure and properties of the bonding interface after explosive cladding were investigated. The results show that the bonding interface had a wavy appearance with solidified melts in a regularly spaced pattern of discrete regions. Adiabatic shear bands and twin structure were found

Y. B. Yan; Z. W. Zhang; W. Shen; J. H. Wang; L. K. Zhang; B. A. Chin

2010-01-01

188

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

Federal Register 2010, 2011, 2012, 2013

...1625-AA00 Safety Zone; Great Western Tube Float; Colorado River; Parker, AZ AGENCY...Parker, Arizona for the Great Western Tube Float on June 8, 2013. This temporary...Commerce is sponsoring the Great Western Tube Float, which is held on the...

2013-06-05

189

Scanning probe microscope observations of fatigue process in magnesium alloy AZ31 near the fatigue limit  

Microsoft Academic Search

In this study, fatigue crack initiation and propagation behavior of magnesium alloy AZ31 within a crystal grain near the fatigue limit were investigated in detail using a scanning probe microscope (SPM). At a stress amplitude slightly higher than the fatigue limit, cracks are arrested by the grain boundary for an extended period.

Z. Y. Nan; S. Ishihara; T. Goshima; R. Nakanishi

2004-01-01

190

241-AZ-101 Waste Tank Color Video Camera System Shop Acceptance Test Report  

SciTech Connect

This report includes shop acceptance test results. The test was performed prior to installation at tank AZ-101. Both the camera system and camera purge system were originally sought and procured as a part of initial waste retrieval project W-151.

WERRY, S.M.

2000-03-23

191

Histone H2A.Z cooperates with RNAi and heterochromatin factors to suppress antisense RNAs  

PubMed Central

Eukaryotic transcriptomes are characterized by widespread transcription of non-coding and antisense RNAs1–3, which is linked to key chromosomal processes, such as chromatin remodeling, gene regulation, and heterochromatin assembly4–7. However, these transcripts can be deleterious, and their accumulation is suppressed by several mechanisms including degradation by the nuclear exosome8,9. The mechanisms by which cells differentiate coding RNAs from transcripts targeted for degradation are not clear. Here we show that the variant histone H2A.Z, which is loaded preferentially at the 5' ends of genes by the Swr1 complex containing a JmjC domain protein, mediates suppression of antisense transcripts in the fission yeast Schizosaccharomyces pombe genome. H2A.Z is partially redundant in this regard with the Clr4/Suv39h-containing heterochromatin silencing complex that is also distributed at euchromatic loci, and with RNAi component Argonaute (Ago1). Loss of Clr4 or Ago1 alone has little effect on antisense transcript levels, but cells lacking either of these factors and H2A.Z show markedly increased levels of antisense RNAs that are normally degraded by the exosome. These analyses suggest that in addition to performing other functions, H2A.Z is a component of a genome indexing mechanism that cooperates with heterochromatin and RNAi factors to suppress read-through antisense transcripts.

Zofall, Martin; Fischer, Tamas; Zhang, Ke; Zhou, Ming; Cui, Bowen; Veenstra, Timothy D.; Grewal, Shiv I. S.

2009-01-01

192

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

Microsoft Academic Search

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

Kaveh Meshinchi Asl; Alireza Tari; Farzad Khomamizadeh

2009-01-01

193

The hot blow forming of AZ31 Mg sheet: Formability assessment and application development  

NASA Astrophysics Data System (ADS)

The hot blow forming of magnesium sheet offers significant opportunity for forming complex, lightweight parts for automotive applications. This paper characterizes the elevated-temperature formability of AZ31 magnesium sheet materials and the effect of processing conditions on the performance of these materials. In addition, magnesium sheet application development at General Motors Corporation is reviewed.

Carter, Jon T.; Krajewski, Paul E.; Verma, Ravi

2008-11-01

194

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

SciTech Connect

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.

Kanjilal, S.K.

1994-12-06

195

78 FR 63869 - Change of Using Agency for Restricted Areas R-2309 and R-2312, AZ  

Federal Register 2010, 2011, 2012, 2013

...2120-AA66 Change of Using Agency for Restricted Areas R-2309 and R-2312, AZ AGENCY: Federal Aviation Administration (FAA...updates the name of the using agency for Restricted Areas R-2309 and R-2312 located in Arizona. This is an...

2013-10-25

196

Influence of geometry on galvanic corrosion of AZ91D coupled to steel  

Microsoft Academic Search

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

Jimmy X. Jia; Guangling Song; Andrej Atrens

2006-01-01

197

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

PubMed Central

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

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

2013-01-01

198

Are Cities Dying?  

Microsoft Academic Search

This paper organizes a discussion of the costs and benefits of cities around the question: Are cities becoming obsolete? While minimizing transport costs for manufactured goods no longer justifies the existence of cities, they still facilitate the division of labor and the flow of ideas. Cities' higher housing, commuting, and pollution costs seem stable over time. Only the costs associated

Edward L. Glaeser

1998-01-01

199

Characterization of ceramic PVD thin films on AZ31 magnesium alloys  

NASA Astrophysics Data System (ADS)

Ceramic thin films have been widely used to protect the metal substrate as coatings in the past years. In order to improve the poor corrosion resistance of AZ31 magnesium alloy, the study in this paper used the electron beam evaporation method to prepare ceramic PVD films on its surface with TiO 2 and Al 2O 3 as donors, respectively. Atomic force microscopy (AFM), scanning electron microscope (SEM), energy dispersive X-ray spectrometer (EDS), Auger electron spectroscopy (AES) and X-ray diffraction (XRD) were used to investigate the surface morphology, composition and microstructure of the thin films. Both films deposited on AZ31 took on compact top surface morphologies and grew as amorphous structures on substrate. AES test not only showed that films compositions deviated the standard stoichiometric ratios, but also found that element Mg diffused into films and existed as magnesium oxide in the TiO x film as well as the AlO x film. In the electrochemical corrosion test, the AlO x coating on AZ31 exhibited the largest electrochemical impedance in a 3.5% NaCl solution. But it did not show better corrosion resistance than others for the poorer adhesion. Even if its thickness was small, the TiO x coating on AZ31 exhibited the best corrosion resistance in this study. According to the observation and analysis, the damage of these films on AZ31 in aggressive solutions was mainly due to the existence of pores, microcracks, vacancies and poor adhesion between coating and substrate.

Wu, Guosong; Zeng, Xiaoqin; Ding, Wenbin; Guo, Xingwu; Yao, Shoushan

2006-08-01

200

Tank 241-AZ-101 criticality assessment resulting from pump jet mixing: Sludge mixing simulation  

SciTech Connect

Tank 241-AZ-101 (AZ-101) is one of 28 double-shell tanks located in the AZ farm in the Hanford Site`s 200 East Area. The tank contains a significant quantity of fissile materials, including an estimated 9.782 kg of plutonium. Before beginning jet pump mixing for mitigative purposes, the operations must be evaluated to demonstrate that they will be subcritical under both normal and credible abnormal conditions. The main objective of this study was to address a concern about whether two 300-hp pumps with four rotating 18.3-m/s (60-ft/s) jets can concentrate plutonium in their pump housings during mixer pump operation and cause a criticality. The three-dimensional simulation was performed with the time-varying TEMPEST code to determine how much the pump jet mixing of Tank AZ-101 will concentrate plutonium in the pump housing. The AZ-101 model predicted that the total amount of plutonium within the pump housing peaks at 75 g at 10 simulation seconds and decreases to less than 10 g at four minutes. The plutonium concentration in the entire pump housing peaks at 0.60 g/L at 10 simulation seconds and is reduced to below 0.1 g/L after four minutes. Since the minimum critical concentration of plutonium is 2.6 g/L, and the minimum critical plutonium mass under idealized plutonium-water conditions is 520 g, these predicted maximums in the pump housing are much lower than the minimum plutonium conditions needed to reach a criticality level. The initial plutonium maximum of 1.88 g/L still results in safety factor of 4.3 in the pump housing during the pump jet mixing operation.

Onishi, Y.; Recknagle, K.

1997-04-01

201

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

PubMed Central

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.

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

2010-01-01

202

A Combination of H2A.Z and H4 Acetylation Recruits Brd2 to Chromatin during Transcriptional Activation  

PubMed Central

H2A.Z is an essential histone variant that has been implicated to have multiple chromosomal functions. To understand how H2A.Z participates in such diverse activities, we sought to identify downstream effector proteins that are recruited to chromatin via H2A.Z. For this purpose, we developed a nucleosome purification method to isolate H2A.Z-containing nucleosomes from human cells and used mass spectrometry to identify the co-purified nuclear proteins. Through stringent filtering, we identified the top 21 candidates, many of which have conserved structural motifs that bind post-translationally modified histones. We further validated the biological significance of one such candidate, Brd2, which is a double-bromodomain-containing protein known to function in transcriptional activation. We found that Brd2's preference for H2A.Z nucleosomes is mediated through a combination of hyperacetylated H4 on these nucleosomes, as well as additional features on H2A.Z itself. In addition, comparison of nucleosomes containing either H2A.Z-1 or H2A.Z-2 isoforms showed that significantly more Brd2 co-purifies with the former, suggesting these two isoforms engage different downstream effector proteins. Consistent with these biochemical analyses, we found that Brd2 is recruited to AR–regulated genes in an H2A.Z-dependent manner and that chemical inhibition of Brd2 recruitment greatly inhibits AR–regulated gene expression. Taken together, we propose that Brd2 is a key downstream mediator that links H2A.Z and transcriptional activation of AR–regulated genes. Moreover, this study validates the approach of using proteomics to identify nucleosome-interacting proteins in order to elucidate downstream mechanistic functions associated with the histone variant H2A.Z.

Draker, Ryan; Ng, Marlee K.; Sarcinella, Elizabeth; Ignatchenko, Vladimir; Kislinger, Thomas; Cheung, Peter

2012-01-01

203

Finding of No Significant Impact and Final Environmental Assessment: Controlling Quagga Mussels in the Cooling Water System at Davis Dam Using Zeguanox(Trade Name) (MOI-401) Laughlin, Nevada and Bullhead City, Arizona.  

National Technical Information Service (NTIS)

The Bureau of Reclamation (Reclamation) prepared an Environmental Assessment (EA) for the use of a commercial formulation composed of Pseudomonas fluorescens CL 145A (P. fluorescens CL 145A, MOI 401), trade named Zequanox, to control quagga mussels (Dreis...

2011-01-01

204

76 FR 51462 - Notice of Release of an Easement Restriction at Phoenix-Mesa Gateway Airport, Mesa, AZ  

Federal Register 2010, 2011, 2012, 2013

...Restriction at Phoenix-Mesa Gateway Airport, Mesa, AZ AGENCY: Federal Aviation...ACTION: Notice of Request to Release Airport Land...the easement is not needed for civilian airport purposes. In exchange for the...

2011-08-18

205

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

SciTech Connect

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

WHITE, D.A.

1999-12-29

206

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

Federal Register 2010, 2011, 2012, 2013

...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...

2011-10-11

207

Jerusalem: City of Dreams, City of Sorrows  

ERIC Educational Resources Information Center

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…

Ricks, Thomas

2011-01-01

208

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

PubMed Central

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.

Baptista, Tiago; Graca, Ines; Sousa, Elsa J.; Oliveira, Ana I.; Costa, Natalia R.; Costa-Pinheiro, Pedro; Amado, Francisco; Henrique, Rui; Jeronimo, Carmen

2013-01-01

209

Biochemical characterization and in vitro activity of AZ513, a noncovalent, reversible, and noncompetitive inhibitor of fatty acid amide hydrolase.  

PubMed

Fatty acid amide hydrolase (FAAH) hydrolyzes several bioactive lipids including the endocannabinoid anandamide. Synthetic FAAH inhibitors are being generated to help define the biological role(s) of this enzyme, the lipids it degrades in vivo, and the disease states that might benefit from its pharmacological modulation. AZ513 inhibits human FAAH (IC(50)=551 nM), is 20-fold more potent against rat FAAH (IC(50)=27 nM), and is inactive at 10 ?M against the serine hydrolases acetylcholinesterase, thrombin, and trypsin. In contrast to most other potent FAAH inhibitors, AZ513 showed no evidence of covalently modifying the enzyme and displayed reversible inhibition. In an enzyme cross-competition assay, AZ513 did not compete with OL-135, an inhibitor that binds to the catalytic site in FAAH, which indicates that AZ513 does not bind to the catalytic site and is therefore noncompetitive with respect to substrate. AZ513 has good cell penetration as demonstrated by inhibition of anandamide hydrolysis in human FAAH-transfected HEK293 cells (IC(50)=360 nM). AZ513 was tested in a rat spinal cord slice preparation where CB(1) activation reduces excitatory post-synaptic currents (EPSCs). In this native tissue assay of synaptic activity, AZ513 reduced EPSCs, which is consistent with inhibiting endogenous FAAH and augmenting endocannabinoid tone. AZ513 has a unique biochemical profile compared with other published FAAH inhibitors and will be a useful tool compound to further explore the role of FAAH in various biological processes. PMID:21645511

Scott, Clay W; Tian, Gaochao; Yu, Xiao Hong; Paschetto, Kathy A; Wilkins, Dee E; Meury, Luc; Cao, Chang Qing; Varnes, Jeffrey; Edwards, Philip D

2011-09-30

210

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

Microsoft Academic Search

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

Liu Liming; Wang Jifeng; Song Gang

2004-01-01

211

Influence of shot peening on notched fatigue strength of the high-strength wrought magnesium alloy AZ80  

Microsoft Academic Search

Influence of shot peening (SP) on notched fatigue strength of the high-strength wrought magnesium alloy AZ80 has been investigated by using different SP media (including glass, Zirblast B30 and Ce–ZrO2 (ZrO2 stabilized by Ce) shots) and various Almen intensities. The results showed that shot peening improved the notched fatigue strength of AZ80 more effectively than the un-notched fatigue strength. The

P. Zhang; J. Lindemann; C. Leyens

2010-01-01

212

Galvanic corrosion of magnesium alloy AZ91D in contact with an aluminium alloy, steel and zinc  

Microsoft Academic Search

An investigation was carried out into the galvanic corrosion of magnesium alloy AZ91D in contact with zinc, aluminium alloy A380 and 4150 steel. Specially designed test panels were used to measure galvanic currents under salt spray conditions. It was found that the distributions of the galvanic current densities on AZ91D and on the cathodes were different. An insulating spacer between

Guangling Song; Birgir Johannesson; Sarath Hapugoda; David StJohn

2004-01-01

213

An organic chromium-free conversion coating on AZ91D magnesium alloy  

NASA Astrophysics Data System (ADS)

Traditional conversion coatings on magnesium alloys are usually immersed in a solution containing hexavalent chromium compounds. However, the replacement treatments have been proposed by the present environmental driving to eliminate hexavalent chromium. In this work, a tannic acid based conversion coating on AZ91D magnesium alloy was obtained by treatment in a solution containing tannic acid and ammonium metavanadate. SEM, XPS and IR were used to determine the morphology and structure of the conversion coatings. Continuous and uniform conversion coating was deposited on AZ91D alloy and the main components of the coatings were Al 2O 3, MgF 2 and penta-hydroxy benzamide-magnesium complex. The formation mechanism of the coating was discussed. Polarization measurement and salt spray test showed that the corrosion resistance of the conversion coating was much higher than that of traditional chromate conversion coating.

Chen, Xiaoming; Li, Guangyu; Lian, Jianshe; Jiang, Qing

2008-12-01

214

Corrosion Behavior of AZ91D Magnesium Alloy in Three Different Physiological Environments  

NASA Astrophysics Data System (ADS)

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

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

2014-01-01

215

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

SciTech Connect

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 Project design criteria. The STEP is a lower tier document based on the W-314 Test and Evaluation P1 an (TEP). Testing includes Validations and Verifications (e.g., Commercial Grade Item Dedication activities, etc), Factory Tests and Inspections (FTIs), installation tests and inspections, Construction Tests and Inspections (CTIs), Acceptance Test Procedures (ATPs), Pre-Operational Test Procedures (POTPs), and Operational Test Procedures (OTPs). The STEP will be utilized in conjunction with the TEP for verification and validation.

Hays, W.H.

1998-08-12

216

Corrosion resistance of a composite polymeric coating applied on biodegradable AZ31 magnesium alloy.  

PubMed

The high corrosion rate of magnesium alloys is the main drawback to their widespread use, especially in biomedical applications. There is a need for developing new coatings that provide simultaneously corrosion resistance and enhanced biocompatibility. In this work, a composite coating containing polyether imide, with several diethylene triamine and hydroxyapatite contents, was applied on AZ31 magnesium alloys pre-treated with hydrofluoric acid by dip coating. The coated samples were immersed in Hank's solution and the coating performance was studied by electrochemical impedance spectroscopy and scanning electron microscopy. In addition, the behavior of MG63 osteoblastic cells on coated samples was investigated. The results confirmed that the new coatings not only slow down the corrosion rate of AZ31 magnesium alloys in Hank's solution, but also enhance the adhesion and proliferation of MG63 osteoblastic cells, especially when hydroxyapatite nanoparticles were introduced in the coating formulation. PMID:23454214

Zomorodian, A; Garcia, M P; Moura e Silva, T; Fernandes, J C S; Fernandes, M H; Montemor, M F

2013-11-01

217

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

SciTech Connect

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 has been carefully examined in an industrial setting. From a survey of the distribution, frequency of occurrence, and fracture surface morphology of cracks, an attempt was made to link the crack types found in the study to process variables. In-mold temperature data collected for a single casting throughout the normal cooling period have been used to validate the heat-flow model which is described in Part 2. The stress analysis, cause of the different cracks, and remedial action are also presented in Part 2.

Cockcroft, S.L.; Brimacombe, J.K. (Univ. of British Columbia, Vancouver, British Columbia (Canada). Centre for Metallurgical Process Engineering); Walrod, D.G.; Myles, T.A. (Carborundum Co., Falconer, NY (United States). Monofrax-S Plant)

1994-06-01

218

Roles for H2A.Z and its acetylation in GAL1 transcription and gene induction, but not GAL1-transcriptional memory.  

PubMed

H2A.Z is a histone H2A variant conserved from yeast to humans, and is found at 63% of promoters in Saccharomyces cerevisiae. This pattern of localization suggests that H2A.Z is somehow important for gene expression or regulation. H2A.Z can be acetylated at up to four lysine residues on its amino-terminal tail, and acetylated-H2A.Z is enriched in chromatin containing promoters of active genes. We investigated whether H2A.Z's role in GAL1 gene regulation and gene expression depends on H2A.Z acetylation. Our findings suggested that H2A.Z functioned both in gene regulation and in gene expression and that only its role in gene regulation depended upon its acetylation. Our findings provided an alternate explanation for results that were previously interpreted as evidence that H2A.Z plays a role in GAL1 transcriptional memory. Additionally, our findings provided new insights into the phenotypes of htz1Delta mutants: in the absence of H2A.Z, the SWR1 complex, which deposits H2A.Z into chromatin, was deleterious to the cell, and many of the phenotypes of cells lacking H2A.Z were due to the SWR1 complex's activity rather than to the absence of H2A.Z per se. These results highlight the need to reevaluate all studies on the phenotypes of cells lacking H2A.Z. PMID:20582323

Halley, Jeffrey E; Kaplan, Tommy; Wang, Alice Y; Kobor, Michael S; Rine, Jasper

2010-01-01

219

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

PubMed Central

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.

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

2013-01-01

220

TIP48/Reptin and H2A.Z Requirement for Initiating Chromatin Remodeling in Estrogen-Activated Transcription  

PubMed Central

Histone variants, including histone H2A.Z, are incorporated into specific genomic sites and participate in transcription regulation. The role of H2A.Z at these sites remains poorly characterized. Our study investigates changes in the chromatin environment at the Cyclin D1 gene (CCND1) during transcriptional initiation in response to estradiol in estrogen receptor positive mammary tumour cells. We show that H2A.Z is present at the transcription start-site and downstream enhancer sequences of CCND1 when the gene is poorly transcribed. Stimulation of CCND1 expression required release of H2A.Z concomitantly from both these DNA elements. The AAA+ family members TIP48/reptin and the histone variant H2A.Z are required to remodel the chromatin environment at CCND1 as a prerequisite for binding of the estrogen receptor (ER?) in the presence of hormone. TIP48 promotes acetylation and exchange of H2A.Z, which triggers a dissociation of the CCND1 3? enhancer from the promoter, thereby releasing a repressive intragenic loop. This release then enables the estrogen receptor to bind to the CCND1 promoter. Our findings provide new insight into the priming of chromatin required for transcription factor access to their target sequence. Dynamic release of gene loops could be a rapid means to remodel chromatin and to stimulate transcription in response to hormones.

Dalvai, Mathieu; Fleury, Laurence; Bellucci, Luca; Kocanova, Silvia; Bystricky, Kerstin

2013-01-01

221

A Histone Acetylation Switch Regulates H2A.Z Deposition by the SWR-C Remodeling Enzyme  

PubMed Central

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

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

2013-01-01

222

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

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.

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

1996-04-01

223

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

Microsoft Academic Search

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

Qing Li; Xiankang Zhong; Junying Hu; Wei Kang

2008-01-01

224

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

Microsoft Academic Search

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

P.. Cavaliere; P. P. De Marco

2007-01-01

225

Electroless nickel-plating on die cast magnesium alloy AZ91D  

Microsoft Academic Search

Electroless nickel-plating on die cast magnesium alloy AZ91D was investigated. Growth of the electroless nickel-plating coating was characterized using scanning electron microscopy. Corrosion resistance of the coating was evaluated by open circuit potential and potentiodynamic polarization curves in 3.5% (mass fraction) NaCl solution. The results show that plating deposition is initiated on the crevices and then spread onto primary ?

JIA Su-qiu; JIA Shu-sheng; YAO Jun

226

Microstructure and tensile properties of friction stir welded AZ31B magnesium alloy  

Microsoft Academic Search

The microstructural change in AZ31B-H24 magnesium (Mg) alloy after friction stir welding (FSW) was examined. The effects of tool rotational speed and welding speed on the microstructure and tensile properties were evaluated. The grain size was observed to increase after FSW, resulting in a drop of microhardness across the welded region from about 70 HV in the base metal to

N. Afrin; D. L. Chen; X. Cao; M. Jahazi

2008-01-01

227

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

Microsoft Academic Search

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

Daniele Pellegrini; Andrea Ghiotti; Stefania Bruschi

2011-01-01

228

Microstructure phenomena and mechanical properties of AZ31B under warm forming conditions  

Microsoft Academic Search

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.

D. Pellegrini; A. Ghiotti; S. Bruschi

2009-01-01

229

Realization of high strength and high ductility for AZ61 magnesium alloy by severe warm working  

Microsoft Academic Search

Extruded Mg–6%Al–1%Zn (AZ61) alloy bar was subjected to 4-pass Equal Channel Angular Extrusion (ECAE) processing at 448–573K. At the processing temperature of 448K, extremely fine grains with the average grain size of 0.5?m are formed as a result of dynamic recrystallization originated by fine Mg17Al12 (?) phase particles having 50–100nm diameter dynamically-precipitated during ECAE processing. The sizes of both ?

Yu Yoshida; Keita Arai; Shota Itoh; Shigeharu Kamado; Yo Kojima

2005-01-01

230

Microstructure and mechanical properties of Si and Sb added AZ91 magnesium alloy  

Microsoft Academic Search

The effect of Si (individual and combined) with 0.2 pct Sb additions on the microstructure and mechanical properties of permanent\\u000a mold AZ91 alloy has been studied. The results indicate that Si addition introduces a Chinese script Mg2Si phase at the grain boundary along with the Mg17Al12-? phase and reduces ductility and strength of the alloy both at room and high

A. Srinivasan; U. T. S. Pillai; B. C. Pai

2005-01-01

231

Development of resin gear balance shaft system for 2AZ-FE engine  

Microsoft Academic Search

In-line 4 engines have many merits when compared to engines with more cylinders, such as low cost, excellent gas mileage, low weight and compactness. However, one disadvantage is a vibration at 2nd order frequency. This vibration can be canceled by applying a 2nd order balance shaft. For the 2AZ-FE engine, a world class balance shaft system was achieved using resin

Makoto Ishikawa; Yukio Nakamura; Norikazu Kodama; Hiroshi Hosoi

2002-01-01

232

Evaluation of microstructural effects on corrosion behaviour of AZ91D magnesium alloy  

Microsoft Academic Search

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

Rajan Ambat; Naing Naing Aung; W Zhou

2000-01-01

233

Source-zone characterization of a chlorinated-solvent contaminated Superfund site in Tucson, AZ  

Microsoft Academic Search

An extensive site-characterization project was conducted at a large chlorinated-solvent contaminated Superfund site in Tucson, AZ. The project consisted of several components, including traditional site-characterization activities, tracer tests, laboratory experiments conducted with core material collected from the site, and mathematical modeling. The primary focus of the work presented herein is the analysis of induced-gradient contaminant elution tests conducted in a

M. L. Brusseau; N. T. Nelson; Z. Zhang; J. E. Blue; J. Rohrer; T. Allen

2007-01-01

234

Tank 241-AZ-101 prototype corrosion probe four month status report  

Microsoft Academic Search

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

Edgemon; Westinghouse Hanford

1996-01-01

235

A GYERMEKVÁLLALÁS, GYERMEKTELENSÉG ÉS A GYERMEK ÉRTÉKE KÖZÖTTI KAPCSOLAT AZ EURÓPAI RÉGIÓ ORSZÁGAIBAN  

Microsoft Academic Search

Európa demográfiai térképén az elmúlt évtizedekben jelent?s változások, át- rendez?dések tapasztalhatók. Ez a megállapítás igaz mind a házasságkötési moz- galom, mind a termékenység, a gyermekvállalási magatartás alakulásának vonat- kozásában is. Korábban magas házasodási hajlandóságú országokban a házasság- kötések jelent?s visszaesése tapasztalható, míg számos korábban kevésbé házaso- dó európai országban a házasságkötési arányszámok csak kismértékben csökken- tek, vagy éppen emelkedést mutattak.

PONGRÁCZ TIBORNÉ

236

AzTEC 1.1 mm OBSERVATIONS OF THE MBM12 MOLECULAR CLOUD  

SciTech Connect

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

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

2012-02-10

237

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

SciTech Connect

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

Morrey, E.V.

1996-03-01

238

Investigation of plasma electrolytic oxidation process on AZ91D magnesium alloy  

Microsoft Academic Search

Ceramic coatings oxidized for different time periods were prepared to characterize the plasma electrolytic oxidation (PEO) process of AZ91D magnesium alloy. The coatings were analyzed using scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscope and potentiodynamic polarization measurement. The results show that the PEO coatings perform different growth behaviors at different PEO stages, and different morphologies are exhibited on ?-

Guo-Hua Lv; Huan Chen; L. Li; Er-Wu Niu; Huan Pang; Bin Zou; Si-Ze Yang

2009-01-01

239

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

Microsoft Academic Search

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

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

2005-01-01

240

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

Microsoft Academic Search

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

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

2008-01-01

241

Experimental Research on a Novel Iodine-125 Seed Strand Connected Using Magnesium Alloy AZ31.  

PubMed

Background and Purpose: Aim of this research is to study the in vivo degradation and biocompatibility in rabb its and the dose distribution of novel iodine-125 seed strands connected using magnesium alloy AZ31. Method: Thirtythree New Zealand rabbits were divided into three Groups (A, B, and C). All rabbits in Groups A and C were implanted with VX2 tumors. For Group A, radioactive iodine-125 seed strands were implanted into the VX2 tumors. For Group B, non-radioactive iodine-125 seed strands were implanted into thigh muscle. Rabbits in Group C were used as controls. Displacement of the seed strands was assessed using X-ray and CT. Blood and urine samples were collected from all groups to measure changes in magnesium ion concentrations. The changing effect of alloy AZ31 tube according to dose distribution of iodine-125 was evaluated using the Monte Carlo method. Results: In Groups A and B, 14 days after implantation, majority of the magnesium alloy tubes were fragmented, and 28 days after implantation, the magnesium alloy tubes were completely degraded. Small differences in dose distribution were observed between bare iodine-125 seeds and iodine-125 seed strands. Conclusions: Our results suggest that these novel iodine-125 seed strands connected using magnesium alloy AZ31 are promising anti-cancer drug for brachytherapy due to the rapid degradation of connective materials and even distribution of seed doses in tumors. Some recent patents are also outlined in this article. PMID:24483348

Li, Chuanxing; Zhang, Yanling; Chen, Dong; Duan, Guangfeng; Liu, Zhenyin; Zhang, Liang; Yang, Guang; Zhang, Tao; Lu, Ming-Jian; Singh, Sristi; Zhang, Weidong; Zhang, Fujun

2014-05-01

242

Central City Business.  

ERIC Educational Resources Information Center

Business owners and managers from 10 large cities were surveyed regarding (1) perceptions of their cities' business climate; (2) plans for increasing/decreasing their work force; and (3) whether they had considered moving/closing their businesses. Results suggest that for central city business to thrive, improvement must occur in urban quality of…

Matz, Deborah

1981-01-01

243

Smart cities in Europe  

Microsoft Academic Search

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

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

2009-01-01

244

Standardizing city tourism statistics  

Microsoft Academic Search

The major problems that city tourism managers face are the availability and comparability of market research information for their own city and their strongest competitors. To overcome this problem in market volume and share studies on European city tourism, an intelligent database system was developed. A comprehensive knowledge acquisition process on the quality and comparability of the statistics led to

Karl W Wöber

2000-01-01

245

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

PubMed

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

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

2013-01-01

246

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

PubMed

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

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

2012-09-01

247

AzTEC/ASTE 1.1 mm Deep Surveys: Number Counts and Clustering of Millimeter-bright Galaxies  

NASA Astrophysics Data System (ADS)

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 of the deepest and widest maps thus far at millimetre and submillimetre wavelengths. We uncovered 198 sources with a significance of 3.5-15.6?, providing the largest catalog of 1.1 mm sources in a contiguous region. Most of the sources are not detected in the far-infrared bands of the AKARI satellite, suggesting that they are mostly at z ? 1.5 given the detection limits. We construct differential and cumulative number counts of the ADF-S, the Subaru/XMM Newton Deep Field (SXDF), and the SSA 22 field surveyed by AzTEC/ASTE, which provide currently the tightest constraints on the faint end. The integration of the differential number counts of the ADF-S find that the contribution of 1.1 mm sources with ?1 mJy to the cosmic infrared background (CIB) at 1.1 mm is 12-16%, suggesting that the large fraction of the CIB originates from faint sources of which number counts are not yet constrained. We estimate the cosmic star-formation rate density contributed by 1.1 mm sources with ?1 mJy using the differential number counts and find that it is lower by about a factor of 5-10 compared to those derived from UV/optically-selected galaxies at z ~ 2-3. Clustering analyses of AzTEC sources in the ADF-S and the SXDF find that bright (>3 mJy) AzTEC sources are more strongly clustered than faint (< 3 mJy) AzTEC sources and the average mass of dark halos hosting bright AzTEC sources was calculated to be 1013-1014M?. Comparison of correlation length of AzTEC sources with other populations and with a bias evolution model suggests that dark halos hosting bright AzTEC sources evolve into systems of clusters at present universe and the AzTEC sources residing the dark halos evolve into massive elliptical galaxies located in the center of clusters.

Hatsukade, B.

2011-11-01

248

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

PubMed Central

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.

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

249

iCity  

Microsoft Academic Search

The objective of this study is to present a novel tool for predictive modelling of urban growth. The proposed tool, named iCity – Irregular City, extends the traditional formalization of cellular automata (CA) to include an irregular spatial structure, asynchronous urban growth, and a high spatio-temporal resolution to aid in spatial decision making for urban planning. The iCity software tool

D. Stevens; S. Dragicevic; Kristina Rothley

2007-01-01

250

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

SciTech Connect

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.

Pardini, Allan F.; Weier, Dennis R.

2007-08-12

251

City of Cambridge: CityViewer  

NSDL National Science Digital Library

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

252

Pulsed Laser Surface Modification of AZ31B with Al-Si  

NASA Astrophysics Data System (ADS)

A pulsed Nd:YAG laser was used to modify the surface properties of Mg alloy (AZ31B) for wear application with Al-Si as precursor material. Highly refined microstructure consisting of Mg2Si, Mg, Al12Mg17 and Al2O3 was obtained. Phase constituent was correlated with thermodynamic calculation by employing Thermocalc™. The evolution of phase amount in the coatings was associated with the laser processing parameters. Due to the presence of highly refined microstructure and hard intermetallic reinforcements, substantial improvement of microhardness has been found in the coating region.

Du, Baoshuai; Paital, Sameer R.; Dahotre, Narendra B.

2012-04-01

253

Fatigue-Property Enhancements of Magnesium Alloy, AZ31B, through Equal-Channel-Angular Pressing (ECAP)  

SciTech Connect

The fatigue behavior of magnesium-alloy, AZ31B, pre-strained by Equal-Channel-Angular Pressing (ECAP) was studied as a function of the accumulated plastic-strain level and the orientation of the samples (along and parallel to the ECAP pressing direction). The material was processed via route BC, at 200 oC, for 1, 2, and 8 passes, with and without a back-pressure applied on the billet during ECAP. The low-cycle fatigue behavior of the AZ31B alloy is shown to be anisotropic and texture-dependent. Due to the initial texture orientation, the specimens loaded parallel to the ECAP pressing direction have a longer fatigue life than the samples loaded perpendicular to it. The low-cycle fatigue life of the AZ31B alloy is enhanced by ECAP. The fatigue-property improvement is discussed in the light of the grain-size refinement, enhanced ductility, and texture evolution.

Wu, Liang [ORNL; Stoica, G. M. [University of Tennessee, Knoxville (UTK); Liao, Hao Hsiang [University of Tennessee, Knoxville (UTK); Agnew, Sean R [University of Virginia; Payzant, E Andrew [ORNL; Wang, Gongyao [ORNL; Fielden, Douglas [ORNL; Chen, Lijia [Shenyang University of Technology; Liaw, Peter K [University of Tennessee, Knoxville (UTK)

2007-01-01

254

From intelligent to smart cities  

Microsoft Academic Search

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,

Mark Deakin; Husam Al Waer

2011-01-01

255

The Happiness of Cities  

Microsoft Academic Search

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

Charlotta Mellander; Peter J. Rentfrow

2011-01-01

256

Salt Lake City, Utah  

NASA Technical Reports Server (NTRS)

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

2002-01-01

257

The Emerging Generic Cities  

Microsoft Academic Search

Cities everywhere have experienced dramatic changes in their size, density, demography and economy in recent decades. With rapid urbanization and globalization of trade and employment, the impact of these changes is all the more apparent in many of the fast growing South Asian and non-western cities. While the likely impact of 9\\/11 on the design of large and tall buildings

Malik A

258

Walkout in Crystal City  

ERIC Educational Resources Information Center

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

Barrios, Greg

2009-01-01

259

Lost City News Release  

NSDL National Science Digital Library

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.

Affairs, Office O.; Foundation, National S.

260

Smart networked cities?  

Microsoft Academic Search

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

Emmanouil Tranos; Drew Gertner

2012-01-01

261

Smart City Components Architicture  

Microsoft Academic Search

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

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

2009-01-01

262

Air pollution in cities  

Microsoft Academic Search

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

Helmut Mayer

1999-01-01

263

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

SciTech Connect

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

Vail, T.S., Fluor Daniel Hanford

1997-02-06

264

CHARACTERIZATION AND FORMABILITY OF CONTINUOUS-CAST AZ31B MAGNESIUM ALLOY SHEETS  

SciTech Connect

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

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

2009-09-24

265

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

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

266

Histone H2A.Z deregulation in prostate cancer. Cause or effect?  

PubMed

Genetic and epigenetic changes are at the root of all cancers. The epigenetic component involves alterations of the post-synthetic modifications of DNA (methylation) and histones (histone posttranslational modifications, PTMs) as well as of those of their molecular "writers," "readers," and "erasers." Noncoding RNAs (ncRNA) can also play a role. Here, we focus on the involvement of histone alterations in cancer, in particular that of the histone variant H2A.Z in the etiology of prostate cancer. The structural mechanisms putatively responsible for the contribution of H2A.Z to oncogenic gene expression programs are first described, followed by what is currently known about the involvement of this histone variant in the regulation of androgen receptor regulated gene expression. The implications of this and their relevance to oncogene deregulation in different stages of prostate cancer, including the progression toward androgen independence, are discussed. This review underscores the increasing awareness of the epigenetic contribution of histone variants to oncogenic progression. PMID:24398858

Dryhurst, Deanna; Ausió, Juan

2014-09-01

267

Continuous Twin Screw Rheo-Extrusion of an AZ91D Magnesium Alloy  

NASA Astrophysics Data System (ADS)

The twin screw rheo-extrusion (TSRE) is designed to take advantage of the nondendritc microstructure and thixotropic characterization of semisolid-metal slurries and produce simple metal profiles directly from melts. The extrusion equipment consists of a rotor-stator high shear slurry maker, a twin screw extruder, and a die assembly. The process is continuous and has a potential for significantly saving energy, manufacturing cost, and enhancing efficiency. The present investigation was carried out to study the process performance for processing rods of an AZ91D magnesium alloy and the microstructure evolution during processing. The semisolid slurry prepared by the process was characterized by uniformly distributed nondendritic granular primary phase particles. AZ91D rods with uniform and fine microstructures and moderate mechanical properties were produced. For the given slurry making parameters, decreasing extrusion temperature was found to improve microstructures and properties. The mechanisms of particle granulation and refinement and the effect of processing parameters on process performance and thermal management are discussed.

Xia, M.; Huang, Y.; Cassinath, Z.; Fan, Z.

2012-11-01

268

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

NASA Astrophysics Data System (ADS)

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%.

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

2010-07-01

269

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

SciTech Connect

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

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

2010-03-15

270

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

USGS Publications Warehouse

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

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

2010-01-01

271

Low-Power Laser/Arc Hybrid Welding Behavior in AZ-Based Mg Alloys  

NASA Astrophysics Data System (ADS)

The low-power laser/arc hybrid welding behaviors of the AZ-based Mg alloys in similar and dissimilar joints are examined in this study in terms of welding parameters, fusion-zone characteristics, mechanical properties, welding temperature fields, and laser-induced arc plasma/plume. Experiments were conducted using a low-power (300 W) pulsed Nd:YAG laser with a gas tungsten welding arc. The results show that the AZ-based Mg alloys can be easily welded by laser/arc hybrid welding process. The introduction of low-power laser beam can stabilize the welding arc even at a high-speed welding, and spattering behavior of laser welding disappeared due to the introduction of welding arc. With the increases of arc power, a higher weld depth can be obtained, and the weld depths for laser and arc acting in combination (laser/arc) are 2 times higher than those of for laser and arc acting separately (laser + arc) in optimal conditions. The postweld tensile strength of Mg alloys could recover ˜80 to 100 pct of the original strength in similar or dissimilar joints. The fatigue strength in laser/arc hybrid welded specimens is equal to that of the unweld base metal.

Liu, L. M.; Song, G.; Zhu, M. L.

2008-07-01

272

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

SciTech Connect

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.

HAMMOND DM; HARRIS JP; MOUETTE P

1997-06-09

273

Inequality and City Size*  

PubMed Central

Between 1979 and 2007 a strong positive monotonic relationship between wage inequality and city size has developed. This paper investigates the links between this emergent city size inequality premium and the contemporaneous nationwide increase in wage inequality. After controlling for the skill composition of the workforce across cities of different sizes, we show that at least 23 percent of the overall increase in the variance of log hourly wages in the United States from 1979 to 2007 is explained by the more rapid growth in the variance of log wages in larger locations relative to smaller locations. This influence occurred throughout the wage distribution and was most prevalent during the 1990s. More rapid growth in within skill group inequality in larger cities has been by far the most important force driving these city size specific patterns in the data. Differences in the industrial composition of cities of different sizes explain up to one-third of this city size effect. These results suggest an important role for agglomeration economies in generating changes in the wage structure during the study period.

Baum-Snow, Nathaniel; Pavan, Ronni

2013-01-01

274

The Influence of Different Heat Treatments on Stress Corrosion Cracking in the Aluminum Alloys al-7050 and Az 7461 de Invloed van Verschillende Warmtebehandelingen OP de Spanningscorrosie-Gevoeligheid van de Aluminium Legeringen al-7050 en Az 74.61.  

National Technical Information Service (NTIS)

Stress corrosion cracking (SCC) susceptibility of two Al-Zn-Mg forging alloys, Al-7050 and AZ 74.61, was investigated for different heat treatments. The constant strain rate (CSR) test method was used. Results of the CSR tests were compared with published...

H. F. Dejong, R. R. Kalmann

1982-01-01

275

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

Microsoft Academic Search

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

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

2005-01-01

276

Pump Jet Mixing and Pipeline Transfer Assessment for High-Activity Radioactive Wastes in Hanford Tank 241-AZ-102  

SciTech Connect

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.

Y Onishi; KP Recknagle; BE Wells

2000-08-09

277

Discriminating nucleosomes containing histone H2A.Z or H2A based on genetic and epigenetic information  

PubMed Central

Background Nucleosomes are nucleoproteic complexes, formed of eight histone molecules and DNA, and they are responsible for the compaction of the eukaryotic genome. Their presence on DNA influences many cellular processes, such as transcription, DNA replication, and DNA repair. The evolutionarily conserved histone variant H2A.Z alters nucleosome stability and is highly enriched at gene promoters. Its localization to specific genomic loci in human cells is presumed to depend either on the underlying DNA sequence or on a certain epigenetic modification pattern. Results We analyzed the differences in histone post-translational modifications and DNA sequences near nucleosomes that do or do not contain H2A.Z. We show that both the epigenetic context and underlying sequences can be used to classify nucleosomal regions, with highly significant accuracy, as likely to either contain H2A.Z or canonical histone H2A. Furthermore, our models accurately recapitulate the observed nucleosome occupancy near the transcriptional start sites of human promoters. Conclusion We conclude that both genetic and epigenetic features are likely to participate in targeting H2A.Z to distinct chromatin loci.

Gervais, Alain L; Gaudreau, Luc

2009-01-01

278

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

Federal Register 2010, 2011, 2012, 2013

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

2010-12-10

279

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

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

2010-10-06

280

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

Federal Register 2010, 2011, 2012, 2013

...AZ AGENCY: Bureau of Land Management, Interior. ACTION: Notice...relocation of the Bureau of Land Management's (BLM) San Pedro Project...20, 2013, at the close of business (4 p.m.), the BLM SPPO...Area and fire and resource management for the area. The...

2013-08-29

281

Selection of FSW tool pin profile, shoulder diameter and material for joining AZ31B magnesium alloy – An experimental approach  

Microsoft Academic Search

In this investigation, an attempt was made to select proper tool pin profile, tool shoulder diameter and tool material to friction stir weld AZ31B magnesium alloy. Five tool pin profiles, five tool materials and three tool shoulder diameters were used to fabricate the joints. Tensile properties of the joints were evaluated and correlated with the weld zone microstructure and hardness.

G. Padmanaban; V. Balasubramanian

2009-01-01

282

Effect of TiN nano-coating on the interface microstructure of carbon fibres-AZ91 alloy composite  

NASA Astrophysics Data System (ADS)

Magnesium matrix composites reinforced with carbon fibres, Cf, without surface modification and coated with TiN nanolayer, (Cf)TiN, were investigated. AZ91 magnesium alloy and carbon fibres of T300B (Toray) PAN type were chosen as components. In the experiment infiltration in vacuum as a method of component consolidation and chemical vapour deposition (CVD) for carbon fibres surface modification were applied. Structural investigations were performed in the Hitachi 3200S field-emission scanning electron microscope (FE-SEM) and on a FEI Tecnai G2 FEG high-resolution transmission electron microscope (TEM) equipped with energy-dispersive X-ray spectrometer (EDS) and high angle annular dark field (HAADF) detectors. SEM observations revealed that at the interface of AZ91-Cf composite destructive phases were formed. An application of TiN nano-coating as a surface modification ensured proper wettability of carbon fibres by liquid metal and protection against the destructive products formation. The microstructure of AZ91-(Cf)TiN composite interface was multilayered. TEM investigation revealed a continuous layer of mixed alumina and magnesia just at the carbon surface, followed by a layer with a dominant concentration of titanium, enriched with Al, O, Mg and C and subsequently a layer of nano-sized Al12Mg17 crystals in the magnesium matrix. Therefore, an applied TiN nano-coating can be classified as an active barrier in AZ91-Cf system.

Olszówka-Myalska, A.; Botor-Probierz, A.

2012-03-01

283

Diffusion Bonding Behavior and Characterization of Joints Made Between 316L Stainless Steel Alloy and AZ31 Magnesium Alloy  

Microsoft Academic Search

The 316L austenitic stainless steel and AZ31 magnesium alloy have physical and mechanical properties which makes these alloys suitable in a number of high technology based industries such as the aerospace and automotive sectors. However, for these alloys to be used in engineering applications, components must be fabricated and joined successfully. The differences in the physical and metallurgical properties between

Waled Mohamed Elthalabawy

2010-01-01

284

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

EPA Science Inventory

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

285

Arsenic Removal from Drinking Water by Adsorptive Media USEPA Demonstration Project at Rimrock AZ Final Performance Evaluation Report  

EPA Science Inventory

This report documents the activities performed during and the results obtained from the arsenic removal treatment technology demonstration project at the Arizona Water Company (AWC) facility in Rimrock, AZ. The objectives of the project were to evaluate: 1) the effectiveness of ...

286

ARSENIC REMOVAL FROM DRINKING WATER BY ADSORPTIVE MEDIA USEPA DEMONSTRATION PROJECT AT VALLEY VISTA, AZ SIX-MONTH EVALUATION REPORT  

EPA Science Inventory

This report documents the activities performed and the results obtained from the first six months of the EPA arsenic removal technology demonstration project at the Arizona Water Company (AWC) facility in Sedona, AZ, commonly referred to as Valley Vista. The main objective of the...

287

An electrochemical analysis of AZ91 Mg alloy processed by plasma electrolytic oxidation followed by static annealing  

Microsoft Academic Search

In this study, the effect of subsequent annealing on the electrochemical response of AZ91 Mg alloy coated via plasma electrolytic oxidation (PEO) was investigated. PEO coating was carried out on the Mg alloy under AC condition in an alkaline silicate electrolyte, and the PEO-coated samples underwent several subsequent annealing treatments at three different temperatures of 100, 150, and 200°C. The

Y. G. Ko; K. M. Lee; B. U. Lee; D. H. Shin

2011-01-01

288

Growth process of plasma electrolytic oxidation films formed on magnesium alloy AZ91D in silicate solution  

Microsoft Academic Search

In order to get a clear picture for describing the growth process of the oxide film formed on magnesium alloy AZ91D under plasma electrolytic oxidation (PEO) in alkaline silicate solution, the characteristics of PEO films formed at different reaction stages were systemically investigated. The results of morphologies, compositions and electronic properties indicated that the PEO films had a different growth

Hongping Duan; Chuanwei Yan; Fuhui Wang

2007-01-01

289

Effects of humidity and contact material on fretting fatigue behavior of an extruded AZ61 magnesium alloy  

Microsoft Academic Search

Fretting fatigue tests of the extruded AZ61 magnesium alloy with the same contact material under low and high humidity were carried out to investigate basic fretting fatigue characteristics and effect of humidity on fretting fatigue behavior. Influence of contact material was also studied by using JIS S45C carbon steel contact material. Degradation of fatigue strength due to fretting was much

Anchalee Saengsai; Yukio Miyashita; Yoshiharu Mutoh

2009-01-01

290

Sedimentological characteristics of the surficial deposits of the Jal Az-Zor area, Kuwait  

NASA Astrophysics Data System (ADS)

The purpose of this article is to discuss the nature and characteristics of the surface geology of the Jal Az-Zor escarpment and the adjacent area, to better understand the sedimentology of desert landforms, and the main factors controlling depositional and diagenetic processes active in this environment. The oldest outcrops along the face of the escarpment are the sand and sandstone sequences of the Mutla and Jal Az-Zor Formations of the Kuwait Group (Neogene). Gravelly deposits of the upper member of the Kuwait Group, Dibdibba Formation (Pleistocene) are restricted to a few hillocks and ridges in the summit area of the escarpment. The Neogene deposits in most of the study area are overlain by a veneer of unconsolidated Holocene sediments. These were classified, according to their morphological setting and field occurrence, into: coastal deposits (intertidal mud, sabkha deposits, and sand dunes) and inland deposits (sand drifts, slope deposits, wadi fills, residual deposits and playa deposits). Wind-born quartzitic sand is the most common Holocene sediment in the study area indicating the dominance of the aeolian processes. Gypsum and carbonate present as cementing materials or in the form of gypcrete and calcrete, respectively, are characteristic sedimentological features of the pre-Holocene deposits. Gypcrete and gypsum cement are abundant in the upper section of the escarpment and decreases downward, whereas the carbonate (calcrete) shows a reverse pattern, i.e., it becomes more dominant in the lower section of the escarpment. The source of sulphate ions in the groundwater that is responsible for the development of gypcrete is believed to be the evaporites in the lower section of the Neogene sequence. The source of ions for the formation of calcrete and calcite cement is less understood due to the lack of significant primary carbonates in the near-surface deposits. It is believed that the nature and distribution of the chemically precipitated material (gypsum and carbonates) are controlled by the chemistry and hydrodynamics of the groundwater which in turn are controlled mostly by the climatic conditions, during their development, and the lithology of the host sediments. Arid and semi-arid climatic and paleoclimatic conditions are considered the most critical factors affecting the depositional and diagenetic processes impacting surficial deposits of the Jal Az-Zor area.

Al-Bakri, D.; Kittaneh, W.; Shublaq, W.

1988-10-01

291

AZ-101 Mixer Pump Demonstration and Tests Data Management Analysis Plan  

SciTech Connect

This document provides a plan for the analysis of the data collected during the AZ-101 Mixer Pump Demonstration and Tests. This document was prepared after a review of the AZ-101 Mixer Pump Test Plan (Revision 4) [1] and other materials. The plan emphasizes a structured and well-ordered approach towards handling and examining the data. This plan presumes that the data will be collected and organized into a unified body of data, well annotated and bearing the date and time of each record. The analysis of this data will follow a methodical series of steps that are focused on well-defined objectives. Section 2 of this plan describes how the data analysis will proceed from the real-time monitoring of some of the key sensor data to the final analysis of the three-dimensional distribution of suspended solids. This section also identifies the various sensors or sensor systems and associates them with the various functions they serve during the test program. Section 3 provides an overview of the objectives of the AZ-101 test program and describes the data that will be analyzed to support that test. The objectives are: (1) to demonstrate that the mixer pumps can be operated within the operating requirements; (2) to demonstrate that the mixer pumps can mobilize the sludge in sufficient quantities to provide feed to the private contractor facility, and (3) to determine if the in-tank instrumentation is sufficient to monitor sludge mobilization and mixer pump operation. Section 3 also describes the interim analysis that organizes the data during the test, so the analysis can be more readily accomplished. Section 4 describes the spatial orientation of the various sensors in the tank. This section is useful in visualizing the relationship of the Sensors in terms of their location in the tank and how the data from these sensors may be related to the data from other sensors. Section 5 provides a summary of the various analyses that will be performed on the data during the test program. Finally, an appendix reviews the technical aspects of the key sensor systems that will be used in the program. This review focuses on the performance capabilities and limits of the sensing systems.

DOUGLAS, D.G.

2000-02-22

292

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.

293

Resistance-Spot-Welded AZ31 Magnesium Alloys: Part I. Dependence of Fusion Zone Microstructures on Second-Phase Particles  

NASA Astrophysics Data System (ADS)

A comparison of microstructural features in resistance spot welds of two AZ31 magnesium (Mg) alloys, AZ31-SA (from supplier A) and AZ31-SB (from supplier B), with the same sheet thickness and welding conditions, was performed via optical microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and transmission electron microscopy (TEM). These alloys have similar chemical composition but different sizes of second-phase particles due to manufacturing process differences. Both columnar and equiaxed dendritic structures were observed in the weld fusion zones of these AZ31 SA and SB alloys. However, columnar dendritic grains were well developed and the width of the columnar dendritic zone (CDZ) was much larger in the SB alloy. In contrast, columnar grains were restricted within narrow strip regions, and equiaxed grains were promoted in the SA alloy. Microstructural examination showed that the as-received Mg alloys contained two sizes of Al8Mn5 second-phase particles. Submicron Al8Mn5 particles of 0.09 to 0.4 ?m in length occured in both SA and SB alloys; however, larger Al8Mn5 particles of 4 to 10 ?m in length were observed only in the SA alloy. The welding process did not have a great effect on the populations of Al8Mn5 particles in these AZ31 welds. The earlier columnar-equiaxed transition (CET) is believed to be related to the pre-existence of the coarse Al8Mn5 intermetallic phases in the SA alloy as an inoculant of ?-Mg heterogeneous nucleation. This was revealed by the presence of Al8Mn5 particles at the origin of some equiaxed dendrites. Finally, the columnar grains of the SB alloy, which did not contain coarse second-phase particles, were efficiently restrained and equiaxed grains were found to be promoted by adding 10 ?m-long Mn particles into the fusion zone during resistance spot welding (RSW).

Xiao, L.; Liu, L.; Zhou, Y.; Esmaeili, S.

2010-03-01

294

PRC1 and PRC2 are not required for targeting of H2A.Z to developmental genes in embryonic stem cells.  

PubMed

The essential histone variant H2A.Z localises to both active and silent chromatin sites. In embryonic stem cells (ESCs), H2A.Z is also reported to co-localise with polycomb repressive complex 2 (PRC2) at developmentally silenced genes. The mechanism of H2A.Z targeting is not clear, but a role for the PRC2 component Suz12 has been suggested. Given this association, we wished to determine if polycomb functionally directs H2A.Z incorporation in ESCs. We demonstrate that the PRC1 component Ring1B interacts with multiple complexes in ESCs. Moreover, we show that although the genomic distribution of H2A.Z co-localises with PRC2, Ring1B and with the presence of CpG islands, H2A.Z still blankets polycomb target loci in the absence of Suz12, Eed (PRC2) or Ring1B (PRC1). Therefore we conclude that H2A.Z accumulates at developmentally silenced genes in ESCs in a polycomb independent manner. PMID:22496869

Illingworth, Robert S; Botting, Catherine H; Grimes, Graeme R; Bickmore, Wendy A; Eskeland, Ragnhild

2012-01-01

295

From intelligent to smart cities  

Microsoft Academic Search

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

Mark Deakin; Husam Al Waer

2011-01-01

296

Metallurgical Evaluation of AZ31B-H24 Magnesium Alloy Friction Stir Welds  

NASA Astrophysics Data System (ADS)

Friction Stir welding of 3.175 mm (0.125 in.) thick plates of AZ31-H24 magnesium alloy was performed using several travel velocities and tool-rotation speeds. After production the welds were cross-sectioned and a metallurgical characterization was performed using optical microscopy, and scanning electron microscopy. Assessment of the weld nugget or “stirred zone” shows evidence of dynamic recrystallization and the start of grain growth in some spots of this region compared to the parent metal. Recrystallization was identified in the thermomechanically affected zone (TAZ) as well. The mechanical properties of the weld are correlated with the corresponding microstructures present in the weld nugget and TMAZ. Corrosion resistance of the weld was assessed using Electrochemical Impedance Spectroscopy (EIS) techniques and immersion tests in a corrosive environment; it showed better corrosion resistance than the base metal.

Pareek, M.; Polar, A.; Rumiche, F.; Indacochea, J. E.

2007-10-01

297

The tensile electroplasticity of magnesium AZ31 alloy with a single pulse of electric current  

NASA Astrophysics Data System (ADS)

The tensile electroplasticity of magnesium AZ31 alloy with a single pulse of electric current is experimentally investigated. A single pulse of electric current with a relatively short duration is applied to the specimen while the specimen is being deformed in plastic region under quasi-static tensile loads. Experimental parameters are selected so that the maximum temperature at the application of the electric current is significantly lower than the general warm forming temperature of the magnesium alloy. A nearly instant decrease of the flow stress (stress-drop) occurs at the application of the electric current. Once the electric current is removed, the flow stress shows a strain hardening until the failure of the specimen. The result of the parameter study shows that the stress-drop and the following hardening behavior strongly depend on the magnitude of the electric energy density (electric energy per unit area).

Vinh, Nguyen Thai; Kim, Min-Sung; Yu, Hyeong-Ho; Hong, Sung-Tae; Kim, Moon-Jo; Han, Heung-Nam; Han, Kyung-Sik

2013-12-01

298

AZ-101 Mixer Pump Test MT Fury Suspended Solids Profiler Application and Testing  

SciTech Connect

Describes the radiation testing and calibration of the AZ-101 tank suspended solids profiler unit mounted on 6 tank riser 24A. The Mt. Fury Suspended Solids Profiler (SSP) is a microprocessor-controlled instrument that measures the turbidity of solid-liquid suspensions and sludges. The profiler is used commercially for the monitoring and control of clarifiers and thickeners in waste treatment, mining, pulp and paper, and other industrial processing facilities. The instrument includes a three inch diameter probe, a Kynar coated coaxial cable, a reel assembly with a clutch and drive shaft, a stepper motor, and electronics. The instrument measures insoluble or suspended solids content in liquids by transmitting infrared energy at a wavelength of 935 nm and measuring the extent of backscatter. This frequency is not affected by solution color. There are two detectors that allow the instrument to operate over a broad range of concentrations, from clear liquids to light sludges.

MACLEAN, G.T.

2000-01-06

299

Formation of Ha-Containing Coating on AZ31 Magnesium Alloy by Micro-Arc Oxidation  

NASA Astrophysics Data System (ADS)

Magnesium and its alloys are potential biodegradable implant materials due to their attractive biological properties. But the use of magnesium is still hampered by its poor corrosion resistance in physiological fluids. In this study, a HA-containing coating was fabricated by micro-arc oxidation (MAO). The active plasma species of micro-discharge was studied by optical emission spectroscopy (OES). The microstructure and composition were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The corrosion behavior and apatite-forming ability were studied by electrochemical tests and immersed samples in simulated body fluids (SBF). The results show that the microdischarge channel model is gas discharges and oxide layer discharges. The elements from the substrate and electrolyte take part in the formation of the coating. The MAO coating significantly improves the corrosion resistance of AZ31 magnesium alloy and enhances the apatite formation ability.

Tang, Hui; Li, Deyu; Chen, Xiuping; Wu, Chao; Wang, Fuping

2013-08-01

300

Mechanical And Microstructural Aspects Of High Temperature Formability Of AZ31 Sheets  

SciTech Connect

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.

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

2007-04-07

301

H2A.Z Maintenance During Mitosis Reveals Nucleosome Shifting on Mitotically Silenced Genes  

PubMed Central

Profound chromatin changes occur during mitosis to allow for gene silencing and chromosome segregation followed by re-activation of memorized transcription states in daughter cells. Using genome-wide sequencing, we found H2A.Z containing +1 nucleosomes of active genes shift upstream to occupy TSSs during mitosis, significantly reducing nucleosome-depleted regions. Single molecule analysis confirmed nucleosome shifting and demonstrated that mitotic shifting is specific to active genes that are silenced during mitosis and thus is not seen on promoters, which are silenced by methylation or mitotically expressed genes. Using the GRP78 promoter as a model, we found H3K4 tri-methylation is also maintained while other indicators of active chromatin are lost and expression is decreased. These key changes provide a potential mechanism for rapid silencing and re-activation of genes during the cell cycle.

Kelly, Theresa K.; Miranda, Tina Branscombe; Liang, Gangning; Berman, Benjamin P.; Lin, Joy C.; Tanay, Amos; Jones, Peter A.

2010-01-01

302

Effect of heat treatments on oxidation kinetics in AZ91 and AM60 magnesium alloys  

SciTech Connect

The effect of heat treatments on a non protective atmosphere (air) on the morphology and composition of the oxide in AM60 and AZ91 alloys has been evaluated. With the aim of evaluating the loss of alloying elements during heat treatment, a study of these alloys has been carried out using thermogravimetric analysis (TGA). In order to determine the nature of the oxides the reaction products generated were evaluated by scanning electron microscopy and X-ray diffraction. Results show that the nature and morphology of the oxides generated are related to the temperature and the time of the heating conditions applied. - Highlights: {yields} The effect of heat treatments on the oxide growth in Mg-Al alloys has been evaluated. {yields} The nature and morphology of the oxides have been characterized. {yields} These oxides are associated to the time and the temperature conditions.

Barrena, M.I., E-mail: ibarrena@quim.ucm.es; Gomez de Salazar, J.M.; Matesanz, L.; Soria, A.

2011-10-15

303

Statistical analysis on static recrystallization texture evolution in cold-rolled AZ31 magnesium alloy sheet.  

PubMed

Cast AZ31B-H24 magnesium alloy, comprising Mg with 3.27 wt% Al and 0.96 wt% Zn, was cold rolled and subsequently annealed. Global texture evolutions in the specimens were observed by X-ray diffractometry after the thermomechanical processing. Image-based microstructure and texture for the deformed, recrystallized, and grown grains were observed by electron backscattered diffractometry. Recrystallized grains could be distinguished from deformed ones by analyzing grain orientation spread. Split basal texture of ca. ą10-15° in the rolling direction was observed in the cold-rolled sample. Recrystallized grains had widely spread basal poles at nucleation stage; strong {0001} basal texture developed with grain growth during annealing. PMID:23920167

Park, Jun-Ho; Ahn, Tae-Hong; Choi, Hyun-Sik; Chung, Jung-Man; Kim, Dong-Ik; Oh, Kyu Hwan; Han, Heung Nam

2013-08-01

304

Advanced gas cooling study for the hospital at Davis-Monthan AFB, AZ. Final report  

SciTech Connect

Based on its experience with a cogeneration project at Tyndall AFB, the Air Force Civil Engineering Support Agency (AFCESA) tasked the US Army Construction Engineering Research Laboratories (USACERL) to perform an analysis to see if such a concept, or some other cooling options, could be of economic benefit at the Air Force medical facility at Davis-Monthan AFB, AZ, where the cost of purchased electrical power is relatively high compared to that of natural gas. USACERL researchers developed a cooling load profile for the facility by reviewing plant records and interviewing plant operators. Boiler logs (daily and monthly) were consulted to determine heating loads, and a spreadsheet was developed to analyze nine options. Savings and first costs were input into the Life Cycle Cost in Design (LCCID) computer program to determine simple paybacks and savings-to-investment ratios for all options. Based on the results of the investigation, preferred options were recommended for meeting the facility cooling load.

Caponegro, M.A.; Brown, W.T.; Pedersen, T.W.

1999-01-01

305

Foxa2 and H2A.Z Mediate Nucleosome Depletion during Embryonic Stem Cell Differentiation  

PubMed Central

SUMMARY Nucleosome occupancy is fundamental for establishing chromatin architecture. However, little is known about the relationship between nucleosome dynamics and initial cell lineage specification. Here, we determine the mechanisms that control global nucleosome dynamics during embryonic stem (ES) cell differentiation into endoderm. Both nucleosome depletion and de novo occupation occur during the differentiation process, with higher overall nucleosome density after differentiation. The variant histone H2A.Z and the winged helix transcription factor Foxa2 both act to regulate nucleosome depletion and gene activation, thus promoting ES cell differentiation, while DNA methylation promotes nucleosome occupation and suppresses gene expression. Nucleosome depletion during ES cell differentiation is dependent on Nap1l1-coupled SWI/SNF and INO80 chromatin remodeling complexes. Thus, both epigenetic and genetic regulators cooperate to control nucleosome dynamics during ES cell fate decisions.

Li, Zhaoyu; Gadue, Paul; Chen, Kaifu; Jiao, Yang; Tuteja, Geetu; Schug, Jonathan; Li, Wei; Kaestner, Klaus H.

2012-01-01

306

Biodegradation behavior of micro-arc oxidized AZ31 magnesium alloys formed in two different electrolytes  

NASA Astrophysics Data System (ADS)

Degradation behavior of coated magnesium alloys is among most prominent factors for their biomedical applications. In this study, bio-corrosion behavior of micro-arc oxidized magnesium AZ31 alloys formed in silicate and phosphate baths was investigated in r-SBF medium. For this purpose polarization behavior and open circuit profile of the coated samples were achieved by electrochemical and immersion tests, respectively. Moreover, the morphology and composition of the coatings were evaluated before and after immersion test using scanning electron microscopy, X-ray diffraction and energy dispersive spectroscopy. The results showed that the phosphate film had better corrosion resistance and greater thickness than silicate film and, in turn, the lesser degradability in SBF solution, so that Ca2+ and PO43- containing compounds were more abundant on silicate film than phosphate film. Moreover phosphate film had greater surface roughness and lesser hydrophilic nature.

Seyfoori, A.; Mirdamadi, Sh.; Khavandi, A.; Raufi, Z. Seyed

2012-11-01

307

Tank 241-AZ-101 prototype corrosion probe four month status report  

SciTech Connect

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.

Edgemon, G.L., Westinghouse Hanford

1996-12-12

308

Laser beam welding of AZ31B-H24 magnesium alloy.  

SciTech Connect

The laser beam weldability of AZ31B magnesium alloy was examined with high power CW CO{sub 2} and pulsed Nd:YAG lasers. The low viscosity and surface tension of the melt pool make magnesium more difficult to weld than steel. Welding parameters necessary to obtain good welds were determined for both CW CO{sub 2} and pulsed Nd:YAG lasers. The weldability of the magnesium alloy was significantly better with the Nd:YAG laser. The cause of this improvement was attributed to the higher absorption of the Nd:YAG beam. A lower threshold beam irradiance was required for welding, and a more stable weldpool was obtained.

Leong, K. H.

1998-09-29

309

Wear resistance of AZ91D magnesium alloy processed by improved laser surface remelting  

NASA Astrophysics Data System (ADS)

We investigate the effects of laser surface remelting on the wear resistance of the AZ91D magnesium alloy. A CO2 continuous laser was used to treat the samples. The sample surface was strengthened by laser-treated area in the shape of stripes. The wear resistance was improved by marked microstructural characteristics, due to the notable effect of laser treatment, such as the grain refinement and very small sized ?-Mg17Al12 dendrite. The microhardness was increased up to 130 HV. And the wear volume loss was reduced by ~70%. The variations in some laser parameters, the output power and the laser scanning speed, also influenced the microstructure and related wear resistance.

Zhang, Zhihui; Lin, Pengyu; Ren, Luquan

2014-04-01

310

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

NASA Astrophysics Data System (ADS)

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.

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

2013-05-01

311

Friction Stir Welded AZ31 Magnesium Alloy: Microstructure, Texture, and Tensile Properties  

NASA Astrophysics Data System (ADS)

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.

Chowdhury, S. H.; Chen, D. L.; Bhole, S. D.; Cao, X.; Wanjara, P.

2013-01-01

312

Effect of Stress Triaxiality on the Flow and Fracture of Mg Alloy AZ31  

NASA Astrophysics Data System (ADS)

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.

Kondori, Babak; Benzerga, A. Amine

2014-07-01

313

Antibiotic Attack (Kinetic City)  

NSDL National Science Digital Library

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

American Association for the Advancement of Science (;)

2005-01-01

314

Universities Scale Like Cities  

PubMed Central

Recent studies of urban scaling show that important socioeconomic city characteristics such as wealth and innovation capacity exhibit a nonlinear, particularly a power law scaling with population size. These nonlinear effects are common to all cities, with similar power law exponents. These findings mean that the larger the city, the more disproportionally they are places of wealth and innovation. Local properties of cities cause a deviation from the expected behavior as predicted by the power law scaling. In this paper we demonstrate that universities show a similar behavior as cities in the distribution of the ‘gross university income’ in terms of total number of citations over ‘size’ in terms of total number of publications. Moreover, the power law exponents for university scaling are comparable to those for urban scaling. We find that deviations from the expected behavior can indeed be explained by specific local properties of universities, particularly the field-specific composition of a university, and its quality in terms of field-normalized citation impact. By studying both the set of the 500 largest universities worldwide and a specific subset of these 500 universities -the top-100 European universities- we are also able to distinguish between properties of universities with as well as without selection of one specific local property, the quality of a university in terms of its average field-normalized citation impact. It also reveals an interesting observation concerning the working of a crucial property in networked systems, preferential attachment.

van Raan, Anthony F. J.

2013-01-01

315

AGU Press Briefing May 29th: Urban Ecology of Phoenix, AZ.  

NSDL National Science Digital Library

Ecologists now accept human beings and our activities as a significant influence on the Earths ecology. ASTER data is being used to better understand urban ecology, in particular how humans build their cities and affect the surrounding environment. Will Stefanov of Arizona State University will present the first set of ASTER images of the urban skeleton of the amount of built structures in 12 cities around the world and discuss the Urban Environmental Monitoring project which will examine 100 urban centers to look for common features (or lack of them) in global city structure and monitor change over time.

Snodgrass, Stuart; Stefanov, Will

2001-05-22

316

Water in the City  

NSDL National Science Digital Library

Water in the City is part of the Franklin Institute Science Museum's Science in the City Web site. The activity is described as a way to investigate the most precious natural resource in cities. The resources accumulated and presented on the site are held within several areas that include Water Basics, Water Science, Philadelphia Water Ways, Worldwide Water Ways, and References and Activities. The water basics page, for example, contains a glossary of water terminology; water trivia; and information on water myths and realities, dams, water power, conserving water, and keeping water clean. Although most resources are from outside sources, the site does a good job of explaining the concepts and providing kids with a single spot to explore other sites with information on this specific subject.

317

Cities Around the World  

NSDL National Science Digital Library

From Carthage to Chicago, this fascinating digital collection from the University of Wisconsin-Milwaukee presents quite a cornucopia of photographic images drawn from the world's cities, past and present. The images are from the American Geographic Society Library, and just two photographers, Harrison Forman and the noted urban geographer, Harold Mayer, took the pictures. All told, there are over 5500 photographic images in this collection, and first-time visitors should read over the brief introductory essays on the scope and content of this project before jumping into the materials. By clicking on the "Cities" section, visitors can browse around the cities with the most photographs, and then they may also wish to perform a detailed search. There are some fun surprises here, including an aerial view of the Union Stock Yards in Chicago and the governor's residence in Dar es Salaam.

318

100 Resilient Cities  

NSDL National Science Digital Library

The future of cities is the subject of much hand-wringing in urban policy circles. As of late, a popular topic has been the concept of urban "resilience" and the Rockefeller Foundation has taken this matter on with its 100 Resilient Cities initiative. On its website, first-time visitors should first explore the "What is Resilience?" area. Here, the topic is explained in detail and an infographic links to a number of helpful resources. Moving on, visitors can explore the foundation's blog and some of the Most Read entries, such as "The Five Fastest Growing Cities" and "Slumdog Urbanism." Each entry features a comments section that allows visitors to chime in with their own thoughts on resilience in the 21st century. The site is rounded out with a nice subscription feature, allowing readers the opportunity to receive email updates once new material is published on the site.

319

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.

320

The Atlantic Cities  

NSDL National Science Digital Library

What will the future of cities be like? It's a riveting question and one that excites the passions of the folks at The Atlantic Cities website. Their work here "explores the most innovative ideas and pressing issues facing today's global cities and neighborhoods." Visitors should browse through their newest articles, which might include "Why Our Kids Need Play" and "How Poverty Taxes the Brain." The site also has some neat features, including the Charts, Photos, and Urban Wonk areas. Geographers and artists will love the Maps section, which includes both scholarly and humorous offerings. First-time visitors should pay special attention here to "A Block-by-Block Map of Brooklyn, in Garbage" and "One Map, A World of Temperatures." Additionally, visitors can also sign up to receive their e-newsletter and other updates, including information about upcoming conferences and lectures sponsored by The Atlantic.

2013-09-23

321

Ultrafine particles in cities.  

PubMed

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

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

2014-05-01

322

H2A.Z depletion impairs proliferation and viability but not DNA double-strand breaks repair in human immortalized and tumoral cell lines.  

PubMed

In mammalian cells, DNA double-strand breaks (DSB) can be repaired by 2 main pathways, homologous recombination (HR) and non-homologous end joining (NHEJ). To give access to DNA damage to the repair machinery the chromatin structure needs to be relaxed, and chromatin modifications play major roles in the control of these processes. Among the chromatin modifications, changes in nucleosome composition can influence DNA damage response as observed with the H2A.Z histone variant in yeast. In mammals, p400, an ATPase of the SWI/SNF family able to incorporate H2A.Z in chromatin, was found to be important for histone ubiquitination and BRCA1 recruitment around DSB or for HR in cooperation with Rad51. Recent data with 293T cells showed that mammalian H2A.Z is recruited to DSBs and is important to control DNA resection, therefore participating both in HR and NHEJ. Here we show that depletion of H2A.Z in the osteosarcoma U2OS cell line and in immortalized human fibroblasts does not change parameters of DNA DSB repair while affecting clonogenic ability and cell cycle distribution. In addition, no recruitment of H2A.Z around DSB can be detected in U2OS cells either after local laser irradiation or by chromatin immunoprecipitation. These data suggest that the role of H2A.Z in DSB repair is not ubiquitous in mammals. In addition, given that important cellular parameters, such as cell viability and cell cycle distribution, are more sensitive to H2A.Z depletion than DNA repair, our results underline the difficulty to investigate the role of versatile factors such as H2A.Z. PMID:24240188

Taty-Taty, Gemael-Cedrick; Courilleau, Celine; Quaranta, Muriel; Carayon, Alexandre; Chailleux, Catherine; Aymard, François; Trouche, Didier; Canitrot, Yvan

2014-02-01

323

The New City Commons  

ERIC Educational Resources Information Center

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)

Crossland, Janice

1975-01-01

324

Big-City Rules  

ERIC Educational Resources Information Center

When it comes to implementing innovative classroom technology programs, urban school districts face significant challenges stemming from their big-city status. These range from large bureaucracies, to scalability, to how to meet the needs of a more diverse group of students. Because of their size, urban districts tend to have greater distance…

Gordon, Dan

2011-01-01

325

New City, New Challenges  

ERIC Educational Resources Information Center

After eight years at the helm of the City College of New York, where Dr. Gregory Williams grew enrollment at the minority-serving institution by 60 percent, instituted more rigorous admissions standards and launched the college's first capital campaign that raised more than $300 million, last fall he became the 27th president of the University of…

Matthews, Frank

2010-01-01

326

City Night Lights Poster  

NSDL National Science Digital Library

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/).

2002-01-01

327

Hazards in the City  

NSDL National Science Digital Library

In this interactive activity adapted from the National Library of Medicine, explore the environmental hazards that might be found at various locations within cities and towns, including construction sites, factories, homes, hospitals, offices and stores, parks, restaurants, rivers and lakes, schools, and vehicles. A background essay, discussion questions, and standards correlations are also provided.

2010-10-04

328

Visit Cell City  

NSDL National Science Digital Library

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.

Glass, Sue

2007-12-12

329

Nature in the City.  

ERIC Educational Resources Information Center

Describes a science program developed by the Cleveland Museum of Natural History, "Nature in the City," in which students and teachers learn together about the natural community surrounding their school. Includes program's rationale, list of "adventures," and methods. Discusses strategies of Sherlock Holmes'"adventure" focusing on animal tracks…

Ferbert, Mary Lou

1981-01-01

330

Industrial Development in Cities  

Microsoft Academic Search

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

Vernon Henderson; Ari Kuncoro; Matt Turner

1995-01-01

331

Accepted into Education City  

ERIC Educational Resources Information Center

Qatar's Education City, perhaps the world's most diverse campus, is almost entirely unknown in the United States, but represents the next step in the globalization of American higher education--international franchising. Aided by technology such as online libraries, distance learning and streaming video, U.S. universities offer--and charge tuition…

Asquith, Christina

2006-01-01

332

Histone H2A.Z prepares the prostate specific antigen (PSA) gene for androgen receptor-mediated transcription and is upregulated in a model of prostate cancer progression.  

PubMed

The histone variant H2A.Z is present at many eukaryotic gene regulatory regions and can affect rates of transcription. Here we show that total H2A.Z and an acetylated form of H2A.Z is mainly present at the prostate specific antigen (PSA) enhancer and promoter in prostate cancer cell lines where the gene is expressed, but the levels decrease during rapid cycles of transcription. Treatment of prostate cancer cells with androgen results in increased H2A.Z levels due to upregulation of the H2A.Z-1, but not the H2A.Z-2 gene. This upregulation is likely the result of increased MYC transcription factor binding that occurs in response to androgen at the H2A.Z-1 promoter. Furthermore, we show that in a LNCaP xenograft model of prostate cancer progression, there is a significant increase of H2A.Z protein in castration resistant LNCaP tumors resulting from increased expression of the H2A.Z-1 gene. While a similar trend was observed in samples from prostate cancer patients, the results were not statistically significant. Nevertheless, there may be a subset of prostate cancers where elevated expression of H2A.Z-1 is indicative of prostate cancer progression to androgen independence. PMID:22055461

Dryhurst, Deanna; McMullen, Bethany; Fazli, Ladan; Rennie, Paul S; Ausió, Juan

2012-02-01

333

Sinking coastal cities  

NASA Astrophysics Data System (ADS)

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.

Erkens, Gilles; Bucx, Tom; Dam, Rien; De Lange, Ger; Lambert, John

2014-05-01

334

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

335

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

NASA Astrophysics Data System (ADS)

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.

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

336

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

Microsoft Academic Search

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

S Mathieu; C Rapin; J Hazan; P Steinmetz

2002-01-01

337

Stress corrosion cracking of gas-tungsten arc welds in continuous-cast AZ31 Mg alloy sheet  

Microsoft Academic Search

AZ31Mg alloy sheet was welded using a gas-tungsten arc (GTA) process over inserts containing 2.3–9.3wt.% Al. The welded specimens were susceptible to SCC in distilled water, with susceptibility increasing with decreasing weld metal Al (or ? particle) concentration. Primary stress corrosion cracks initiated at the weld metal–HAZ interface by stress-assisted localised dissolution and propagated through the weld and base metals

N. Winzer; P. Xu; S. Bender; T. Gross; W. E. S. Unger; C. E. Cross

2009-01-01

338

Effect of TiN nano-coating on the interface microstructure of carbon fibres-AZ91 alloy composite  

Microsoft Academic Search

Magnesium matrix composites reinforced with carbon fibres, Cf, without surface modification and coated with TiN nanolayer, (Cf)TiN, were investigated. AZ91 magnesium alloy and carbon fibres of T300B (Toray) PAN type were chosen as components. In the experiment infiltration in vacuum as a method of component consolidation and chemical vapour deposition (CVD) for carbon fibres surface modification were applied. Structural investigations

A Olszówka-Myalska; A Botor-Probierz

2012-01-01

339

Biochemical characterization and in vitro activity of AZ513, a noncovalent, reversible, and noncompetitive inhibitor of fatty acid amide hydrolase  

Microsoft Academic Search

Fatty acid amide hydrolase (FAAH) hydrolyzes several bioactive lipids including the endocannabinoid anandamide. Synthetic FAAH inhibitors are being generated to help define the biological role(s) of this enzyme, the lipids it degrades in vivo, and the disease states that might benefit from its pharmacological modulation. AZ513 inhibits human FAAH (IC50=551nM), is 20-fold more potent against rat FAAH (IC50=27 nM), and

Clay W Scott; Gaochao Tian; Xiao Hong Yu; Kathy A. Paschetto; Dee E. Wilkins; Luc Meury; Chang Qing Cao; Jeffrey Varnes; Philip D. Edwards

2011-01-01

340

Initial corrosion behavior of AZ91 magnesium alloy in simulating acid rain under wet-dry cyclic condition  

Microsoft Academic Search

Corrosion behavior of AZ91 magnesium alloy in simulating acid rain under wet-dry cyclic condition was investigated. The results show that corrosion potential shifts positively and the corrosion current density decreases at low wet-dry cyclic time. Further increase of the cyclic time results in the negative movement of corrosion potential and the increase of current density. SEM observation indicates that corrosion

Wan-qiu ZHOU; Da-yong SHAN; En-hou HAN; Wei KE

2008-01-01

341

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

SciTech Connect

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.

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

342

PP-R, 7-(2-hydroxyethyl)-monascorubramine, a red pigment produced in the mycelia of Penicillium sp. AZ.  

PubMed

A red pigment was extracted and purified from the mycelia of a newly isolated strain of Penicillium sp., Penicillium sp. AZ, which produced a soluble violet pigment PP-V, 12-carboxyl-monascorubramine, in the culture fluid. The red pigment, PP-R, was determined by FAB-MS and 1H and 13C NMR to be a novel compound, 7-(2-hydroxyethyl)-monascorubramine. PMID:16232944

Ogihara, J; Kato, J; Oishi, K; Fujimoto, Y

2001-01-01

343

The Redshift and Nature of AzTEC/COSMOS 1: A Starburst Galaxy at z = 4.6  

NASA Astrophysics Data System (ADS)

Based on broadband/narrowband photometry and Keck DEIMOS spectroscopy, we report a redshift of z = 4.64+0.06 -0.08 for AzTEC/COSMOS 1, the brightest submillimeter galaxy (SMG) in the AzTEC/COSMOS field. In addition to the COSMOS-survey X-ray to radio data, we report observations of the source with Herschel/PACS (100, 160 ?m), CSO/SHARC II (350 ?m), and CARMA and PdBI (3 mm). We do not detect CO(5 ? 4) line emission in the covered redshift ranges, 4.56-4.76 (PdBI/CARMA) and 4.94-5.02 (CARMA). If the line is within this bandwidth, this sets 3? upper limits on the gas mass to lsim8 × 109 M sun and lsim5 × 1010 M sun, respectively (assuming similar conditions as observed in z ~ 2 SMGs). This could be explained by a low CO-excitation in the source. Our analysis of the UV-IR spectral energy distribution of AzTEC 1 shows that it is an extremely young (lsim50 Myr), massive (M * ~ 1011 M sun), but compact (lsim2 kpc) galaxy, forming stars at a rate of ~1300 M sun yr-1. Our results imply that AzTEC 1 is forming stars in a "gravitationally bound" regime in which gravity prohibits the formation of a superwind, leading to matter accumulation within the galaxy and further generations of star formation. Based on observations with the W. M. Keck Observatory, the Canada-France-Hawaii Telescope, the United Kingdom Infrared Telescope, the Subaru Telescope, the NASA/ESA Hubble Space Telescope, the NASA Spitzer Telescope, the Caltech Sub-mm Observatory, the Smithsonian Millimeter Array, and the National Radio Astronomy Observatory. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

Smol?i?, V.; Capak, P.; Ilbert, O.; Blain, A. W.; Salvato, M.; Aretxaga, I.; Schinnerer, E.; Masters, D.; Mori?, I.; Riechers, D. A.; Sheth, K.; Aravena, M.; Aussel, H.; Aguirre, J.; Berta, S.; Carilli, C. L.; Civano, F.; Fazio, G.; Huang, J.; Hughes, D.; Kartaltepe, J.; Koekemoer, A. M.; Kneib, J.-P.; LeFloc'h, E.; Lutz, D.; McCracken, H.; Mobasher, B.; Murphy, E.; Pozzi, F.; Riguccini, L.; Sanders, D. B.; Sargent, M.; Scott, K. S.; Scoville, N. Z.; Taniguchi, Y.; Thompson, D.; Willott, C.; Wilson, G.; Yun, M.

2011-04-01

344

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

SciTech Connect

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.

WHITE, D.A.

2000-01-27

345

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

SciTech Connect

Shop Test of the Gamma 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.

WHITE, D.A.

2000-03-01

346

Determination of the flow stress of magnesium AZ31-O sheet at elevated temperatures using the hydraulic bulge test  

Microsoft Academic Search

Elevated temperature hydraulic bulge tests for Mg AZ31-O alloy sheets were conducted using a submerged tool, designed to minimize the temperature variation in the sheet. Experiments were conducted between room temperature and 225°C, at various approximate true strain rates. Bulge profiles at different bulge heights were measured using a CMM and the best radius values were calculated through least-square fit

S. Kaya; T. Altan; P. Groche; C. Klöpsch

2008-01-01

347

Effects of dust and salt particles on the formation and spreading of micro-droplets on AZ91 magnesium alloy  

Microsoft Academic Search

The effects of dust and salt particles on the formation and spreading of micro-droplets on as-cast AZ91 magnesium alloy in an atmosphere of water vapor were investigated using an environmental scanning electron microscope (ESEM). The in situ observations results indicated that both dust particle and AlMn phase stimulated the formation and spreading of micro-droplets, but had few influences on the

Jian Chen; Jianqiu Wang; Enhou Han; Wei Ke

2008-01-01

348

Effect of electrolyte additives on performance of plasma electrolytic oxidation films formed on magnesium alloy AZ91D  

Microsoft Academic Search

Various plasma electrolytic oxidation (PEO) films were prepared on magnesium alloy AZ91D in a silicate bath with different additives such as phosphate, fluoride and borate. Effects of the additives on chemical composition and corrosion resistance of the PEO films were examined by means of scanning electron microscopy (SEM), potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) in 3.5% NaCl solution. The

Hongping Duan; Chuanwei Yan; Fuhui Wang

2007-01-01

349

Application of Drucker–Prager plasticity to predict fracture in rectangular cup drawing of AZ31 alloy sheet  

Microsoft Academic Search

The formability in three-dimensional rectangular cup drawing of AZ31 magnesium alloy sheet is successfully predicted by the Drucker–Prager plasticity (DP model). Numerical results show that the punch corner shoulder is under the condition of high tension bending and the die corner shoulder is on pure bending regardless of constitutive models. The failure is attributed to the competition between the biaxial

Fenghua Wang; Jie Dong; Miaolin Feng; Xingwei Zheng; Wenjiang Ding

350

Bushehr as an Energic City  

NASA Astrophysics Data System (ADS)

Bushehr city is one of the famous city in the south of Iran which is situated in the coastal part of Persian Gulf. This paper try to discuss one of the most important theme which threat the sustainability and comfortability of tomorrow`s life. Changing Bushehr into an Energic city is one of the effective ways to solve the cities problem. For this purpose, we try to answer these questions: what is called as an energic city?; What are its main characteristics?; What are the aims of changing a city into an energic city? And what should be done to obtain the aims? For these purposes we offer a model which responds to the sustainability of Bushehr. This model uses 3 levels of activity that each level should respond to 5 significant characteristics of an energic city. For this purpose we present some applied ways in each category to obtain those characteristics.

Sabatsani, Nasser

351

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

PubMed Central

The histone variant H2A.Z is evolutionarily conserved and plays an essential role in mice, Drosophila, and Tetrahymena. The essential function of H2A.Z is unknown, with some studies suggesting a role in transcriptional repression and others in activation. Here we show that Caenorhabditis elegans HTZ-1/H2A.Z and the remodeling complex MYS-1/ESA1–SSL-1/SWR1 synergize with the FoxA 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 reveals that this interaction is specific, and thus pha-4 is acutely sensitive to reductions in these three proteins. Using a nuclear spot assay to visualize HTZ-1 in living embryos as organogenesis proceeds, we show that HTZ-1 is recruited to foregut promoters at the time of transcriptional onset, and this recruitment requires PHA-4. Loss of htz-1 by RNAi is lethal and leads to delayed expression of a subset of foregut genes. Thus, the effects of PHA-4 on temporal regulation can be explained in part by recruitment of HTZ-1 to target promoters. We suggest PHA-4 and HTZ-1 coordinate temporal gene expression by modulating the chromatin environment.

Updike, Dustin L; Mango, Susan E

2006-01-01

352

Development of a Binary Zn-Based Solder Alloy for Joining Wrought Magnesium Alloy AZ31B  

NASA Astrophysics Data System (ADS)

In the present article, the wrought magnesium alloy AZ31B sheets were soldered by means of high-frequency induction heating device using a novel binary Zn-based solder alloy in argon gas shield condition. The interfacial microstructure, phase constitution, and fracture morphology of the soldered joint were studied. The microhardness and shear strength of the soldered joint were tested. The experimental results exhibit that ?-Mg solid solution and ?-MgZn phase were formed in soldering region. Moreover, the ?-Mg7Zn3 phase in the original Zn-based solder alloy disappeared completely after the soldering process due to the fierce alloying between the molten binary Zn-based solder alloy and the base metal AZ31B during soldering. Test results show that the shear strength of the soldered joint is 28 MPa. The fracture morphology of the soldered joint displays an intergranular fracture mode, and the crack originates from ?-Mg + ?-MgZn eutectoid structure. The interaction between the molten Zn-based solder alloy and the base metal AZ31B leads the Zn-based solder alloy to be transformed into Mg-based soldering metal during soldering.

Ma, Li; Long, Weimin; Qiao, Peixin; He, Dingyong; Li, Xiaoyan

2013-01-01

353

Corrosion fatigue behaviors of two biomedical Mg alloys - AZ91D and WE43 - In simulated body fluid.  

PubMed

Magnesium alloys have been recently developed as biodegradable implant materials, yet there has been no study concerning their corrosion fatigue properties under cyclic loading. In this study the die-cast AZ91D (A for aluminum 9%, Z for zinc 1% and D for a fourth phase) and extruded WE43 (W for yttrium 4%, E for rare earth mischmetal 3%) alloys were chosen to evaluate their fatigue and corrosion fatigue behaviors in simulated body fluid (SBF). The die-cast AZ91D alloy indicated a fatigue limit of 50MPa at 10? cycles in air compared to 20MPa at 10? cycles tested in SBF at 37°C. A fatigue limit of 110MPa at 10? cycles in air was observed for extruded WE43 alloy compared to 40MPa at 10? cycles tested in SBF at 37°C. The fatigue cracks initiated from the micropores when tested in air and from corrosion pits when tested in SBF, respectively. The overload zone of the extruded WE43 alloy exhibited a ductile fracture mode with deep dimples, in comparison to a brittle fracture mode for the die-cast AZ91D. The corrosion rate of the two experimental alloys increased under cyclic loading compared to that in the static immersion test. PMID:20656074

Gu, X N; Zhou, W R; Zheng, Y F; Cheng, Y; Wei, S C; Zhong, S P; Xi, T F; Chen, L J

2010-12-01

354

Influence of shot peening on corrosion properties of biocompatible magnesium alloy AZ31 coated by dicalcium phosphate dihydrate (DCPD).  

PubMed

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

Mhaede, Mansour; Pastorek, Filip; Hadzima, Branislav

2014-06-01

355

Laser Keyhole Welding of Dissimilar Ti-6Al-4V Titanium Alloy to AZ31B Magnesium Alloy  

NASA Astrophysics Data System (ADS)

Laser keyhole welding of Ti-6Al-4V titanium alloy to AZ31B magnesium alloy was developed, and the correlations of process parameters, joint properties, and bonding mechanism were studied. The results show that the offset from the laser beam center on AZ31B side to the edge of the weld seam plays a big role in the joint properties by changing the power density irradiated at the Ti-Mg initial interface. The optimal range of the offset is 0.3 to 0.4mm in the present study. Some lamellar and granular Ti-rich mixtures are observed in the fusion zone, which is formed by intermixing melted Ti-6Al-4V with liquid AZ31B. The maximum ultimate tensile strength of the joints reaches 266 MPa. Furthermore, the fracture surface consists of scraggly remaining weld metal and smooth Ti surface. The higher the failure strength, the smaller the proportion of smooth Ti surface to whole interface is. Finally, the bonding mechanism of the interfacial layer is summarized by the morphologies and test results of fracture surfaces.

Gao, M.; Wang, Z. M.; Li, X. Y.; Zeng, X. Y.

2012-01-01

356

Smart cities and service integration  

Microsoft Academic Search

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.

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

357

High current pulsed electron beam treatment of AZ31 Mg alloy  

SciTech Connect

This paper reports, for the first time, an analysis of the effect of High Current Pulsed Electron Beam (HCPEB) on a Mg alloy. The AZ31 alloy was HCPEB treated in order to see the potential of this fairly recent technique in modifying its wear resistance. For the 2.5 J/cm{sup 2} beam energy density used in the present work, the evaporation mode was operative and led to the formation of a ''wavy'' surface and the absence of eruptive microcraters. The selective evaporation of Mg over Al led to an Al-rich melted surface layer and precipitation hardening from the over saturated solid solution. Due to the increase in hardness of the top surface layer, the friction coefficient values were lowered by more than 20% after the HCPEB treatments, and the wear resistance was drastically (by a factor of 6) improved. The microhardness of the HCPEB samples was also increased significantly down to a depth of about 500 {mu}m, far exceeding the heat-affected zone (about 40 {mu}m). This is due to the effect of the propagation of the shockwave associated with this HCPEB treatment.

Gao Bo; Hao Shengzhi; Zou Jianxin; Grosdidier, Thierry; Jiang Limin; Zhou Jiyang; Dong Chuang [State Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams and Department of Materials Engineering, Dalian University of Technology, Dalian 116024 (China); Laboratoire d'Etude des Textures et Applications aux Materiaux (LETAM, UMR-CNRS 7078), Universite de Metz, Ile du Saulcy, 57 012 Metz (France); State Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams and Department of Materials Engineering, Dalian University of Technology, Dalian 116024 (China)

2005-11-15

358

Microstructure and Mechanical Properties of AZ31 Magnesium Alloy Sheet by Hot Rolling  

NASA Astrophysics Data System (ADS)

AZ31 magnesium alloy sheets with a thickness of about 2mm were prepared by using a unique hot rolling process which was featured by heating the rolls during rolling. Two different rolling routes were used to achieve the final thickness through 6 passes of rolling. The major rolling parameters were chosen as the same for both rolling routes except that the roll temperature was set to be 400°C for route A and the 1st to 4th passes of route B, but lowered to 350°C for the 5th and 6th passes of route B. The microstructure and mechanical properties of the alloy sheets were comparatively investigated. The results showed that dynamic recrystallization occurred during hot rolling, and by choosing the processing parameters appropriately the grain size could be refined steadily with increasing rolling passes. The final alloy sheet prepared by 6 passes of rolling via the rolling route B was featured by a very fine microstructure, with the grain size being 5?m in average. Correspondingly, it presented very high strength and tensile elongation, with its yield strength and tensile elongation achieving 206MPa and 26.4% in the transverse, and 196MPa and 27.6% in the rolling direction, respectively.

Miao, Qing; Hu, Lianxi; Wang, Erde; Liang, Shujin; Chao, Hongying

359

A study of strontium doped calcium phosphate coatings on AZ31.  

PubMed

Calcium phosphate (CaP) coatings have been studied to tailor the uncontrolled non-uniform corrosion of Mg based alloys while simultaneously enhancing bioactivity. The use of immersion techniques to deposit CaP coatings is attractive due to the ability of the approach to coat complex structures. In the current study, AZ31 substrates were subjected to various pretreatment conditions prior to depositing Sr(2+) doped and undoped CaP coatings. It was hypothesized that the bioactivity and corrosion protection of CaP coatings could be improved by doping with Sr(2+). Heat treatment to elevated temperatures resulted in the diffusion of alloying elements, Mg and Zn, into the pretreated layer. Sr(2+) doped and undoped CaP coatings formed on the pretreated substrates consisted of biphasic mixtures of ?-tricalcium phosphate (?-TCP) and hydroxyapatite (HA). Electrochemical corrosion experiments indicated that the extent of Sr(2+) doping and pretreatment both influenced the corrosion protection. Cytotoxicity was evaluated with MC3T3-E1 mouse preosteoblasts and human mesenchymal stem cells (hMSCs). For both cell types, proliferation decreased upon increasing the Sr(2+) concentration. However, both osteogenic gene and protein expression significantly increased upon increasing Sr(2+) concentration. These results suggest that Sr(2+) doped coatings are capable of promoting osteogenic differentiation on degradable Mg alloys, while also enhancing corrosion protection, in comparison to undoped CaP coatings. PMID:24857503

Singh, Satish S; Roy, Abhijit; Lee, Boeun E; Ohodnicki, John; Loghmanian, Autrine; Banerjee, Ipsita; Kumta, Prashant N

2014-07-01

360

Potential bioactivity of coatings formed on AZ91D magnesium alloy by plasma electrolytic anodizing.  

PubMed

Magnesium is a potential candidate as biodegradable orthopedic implant thanks to its remarkable mechanical properties closed to those of natural bone. But its low corrosion resistance in the body fluid is a limiting factor. By using electrolytic plasma (or microarc) anodizing process, 10-20 ?m protective coatings were formed on AZ91D magnesium alloys at a constant current density of 20 mA cm(-2). The effect of a small addition of CaO (1-3 g L(-1)) to a classical electrolytic bath (made of KOH 3 mol L(-1), KF 0.5 mol L(-1), and K(2)HPO(4) 1 mol L(-1)) was studied. The anodic films, investigated by X-ray diffraction and scanning electron microscope-energy dispersive spectroscopy, show a porous structure containing crystallized Mg(OH)(2), MgO, MgAl(2)O(4), as well as Ca and P elements. The 1 g L(-1) CaO-containing electrolyte leads to morphology and composition permitting optimum corrosion behavior evaluated by stationary electrochemical measurements and impedance spectroscopy. This improvement is associated with both the appearing of a "sealing" layer and the precipitation of an outermost Ca/P-containing layer (hydroxyapatite like) in simulated body fluid. The control of the corrosion behavior of coated magnesium alloys is therefore required to enhance their potential bioactivity. PMID:22807000

Vu, Thanh-Nam; Veys-Renaux, Delphine; Rocca, Emmanuel

2012-10-01

361

Single-molecule tools elucidate H2A.Z nucleosome composition  

PubMed Central

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.

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

2012-01-01

362

Histone Variant H2A.Z and RNA Polymerase II Transcription Elongation ?  

PubMed Central

Nucleosomes containing histone variant H2A.Z (Htz1) serve to poise quiescent genes for activation and transcriptional initiation. However, little is known about their role in transcription elongation. Here we show that dominant mutations in the elongation genes SPT5 and SPT16 suppress the hypersensitivity of htz1? strains to drugs that inhibit elongation, indicating that Htz1 functions at the level of transcription elongation. Direct kinetic measurements of RNA polymerase II (Pol II) movement across the 9.5-kb GAL10p-VPS13 gene revealed that the elongation rate of polymerase is 24% slower in the absence of Htz1. We provide evidence for two nonexclusive mechanisms. First, we observed that both the phospho-Ser2 levels in the elongating isoform of Pol II and the loading of Spt5 and Elongator over the GAL1 open reading frame (ORF) depend on Htz1. Second, in the absence of Htz1, the density of nucleosome occupancy is increased over the GAL10p-VPS13 ORF and the chromatin is refractory to remodeling during active transcription. These results establish a mechanistic role for Htz1 in transcription elongation and suggest that Htz1-containing nucleosomes facilitate Pol II passage by affecting the correct assembly and modification status of Pol II elongation complexes and by favoring efficient nucleosome remodeling over the gene.

Santisteban, Maria Soledad; Hang, Mingda; Smith, M. Mitchell

2011-01-01

363

Investigation of the gas-jet ejector in KamAZ trucks  

SciTech Connect

This article considers the possibility of using gas-jet vacuum pumps in tank trucks for transporting liquids (water) at drilling sites. The discharge system of the KamAZ trucks can be reliably sealed by an engine brake, an important prerequisite of reliable operation of a gas-jet ejector that is switched on when the tank is being filled. The ejector consists of a housing, a Laval nozzle, a front wall with cylindrical neck, a tin-plate diffuser, an air supply pipe, and a flange for attaching the ejector to the flange of the exhaust muffler of the truck. The gas-jet ejectors are driven by the exhaust gas (EG) of the trucks. The dependences of the EG flow rate, fuel expenditure, EG temperature ahead of the ejector, and the rotational frequency of the engine crankshaft on the diameter at different EG pressures. It is recommended that gas-jet ejectors be used on series produced tank trucks instead of rotary vacuum pumps with mechanical drive.

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

1984-03-01

364

Assessment of in vitro temporal corrosion and cytotoxicity of AZ91D alloy.  

PubMed

Magnesium alloys represent a valuable option for the production of bioresorbable implantable medical devices aimed to improve the therapeutic approach and minimize the potential risks related to biostable materials. In this regard, the degradation process needs to be carefully evaluated in order to assess the effectiveness of the regenerative support and the eventual toxic effects induced by the released corrosion products. Aluminium is one of the most common alloying element that raised several safety concerns, contributing to shift the investigation toward Al-free alloys. To delve into this issue, a long-term investigation (up to 28 days) was performed using AZ91D alloy, due to its relevant Al content. Immersion tests in phosphate buffered saline (PBS) solution was performed following the ASTM standards and the corrosion behaviour was evaluated at fixed time points by means of electrochemical techniques. Cytotoxic effects were assessed by culturing human neuroblastoma cells with conditioned medium derived from immersion tests at different dilution degree. An increase in the resistance corrosion with the time was observed. In all the investigated cases the presence of Al in the conditioned media did not induce significant toxic effects directly correlated to its content. A decrease of cell viability was only observed in the case of 50 % dilution of PBS conditioned for the longest immersion period (i.e., 28 days). PMID:22802105

Del Gaudio, Costantino; Bagalŕ, Paolo; Venturini, Marco; Grandi, Claudio; Parnigotto, Pier Paolo; Bianco, Alessandra; Montesperelli, Giampiero

2012-10-01

365

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

NASA Astrophysics Data System (ADS)

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%.

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

2013-09-01

366

Interfacial chemistry of organic conversion film on AZ61 magnesium alloy surface  

NASA Astrophysics Data System (ADS)

The anodic electrochemical behavior of AZ61 magnesium alloy in sodium hydroxide medium in the absence and presence of p-nitro-benzene-azo-resorcinol (PNBAR) was studied using electrochemical techniques. In the presence of PNBAR, organic conversion film formed on the surface of magnesium alloy. The nature of chemical mechanisms, bonds, and structures at the interface of PNBAR/magnesium alloy was investigated by using energy dispersive spectrometer (EDS) analysis and Fourier transform infrared spectroscopy. An in situ electrochemical deposition was evidenced to produce a corrosion protective barrier by the formation of organic conversion film of magnesium-PNBAR complex and to enhance film adhesion by the covalent bonds of Mg sbnd O sbnd N linkage. The linear sweep voltammetry experiments and the score tests were used to investigate the adhesion and evaluate the potential of corrosion resistance of organic conversion film. The results indicated the corrosion resistance of magnesium alloy was improved, the organic conversion film showed excellent adhesion not only to the substrate but also to the outer paint coatings.

Yang, Xu; Pan, Fusheng; Zhang, Dingfei

2008-12-01

367

Constitutive model of AZ31B sheet at various pre-strains and temperatures  

NASA Astrophysics Data System (ADS)

Due to their high specific strength, vibration absorption capability, and excellent corrosion resistance, Mg alloys have been potential alternative to other lightweight materials in the automotive industry. Mg alloys are known to have unique mechanical properties; i.e., yielding asymmetry, anisotropy, unusual hardening behavior at room temperature. Usually, Mg alloy sheets have inferior formability at room temperature, but the formability increases when the temperature increases. Moreover, the asymmetry and anisotropy become less significant due to the activation of non-basal slip systems at higher temperature. Utilizing this unique properties, the forming of Mg alloy sheets has been frequently conducted at the temperature of 200 °C or higher, at which twinning effect is less dominant. However, the forming process at elevated temperature lowers production speed due to the additional heating and cooling stages. To resolve this problem, studies on technology that maximizes the formability of Mg alloy sheets at lower temperature have been widely conducted. In this paper, the response of AZ31B Mg alloy sheets under tension-compression cyclic loading at different pre-strains and temperatures was measured experimentally. Then a practical hardening model was developed to reproduce the measured stress-strain responses, which can be applied to the simulation of sheet metal forming of Mg alloy sheets.

Kim, Heon Young; Seo, Oh Suk; Lee, Chung An; Kim, Ji Hoon; Nguyen, Ngoc-Trung; Lee, Myoung-Gyu

2013-12-01

368

Muncie City Improvement Resolutions  

NSDL National Science Digital Library

Municipal improvement resolutions may not be everyone's cup of tea, but this digital collection should win over skeptics of all sorts. The people at Ball State University's Digital Media Repository have digitized over 1,000 items. The records include city ordinances, resolutions, and other materials from the City Clerk's office in Muncie, Indiana. Their creation dates range from 1892 to 1922 and their subjects include street, alley, sidewalk, and sewer improvements in the area. The archive is a very compelling look into urban development as it shows an increased interest (and at times, resistance) to all sorts of improvements from property owners, local businesspeople, and elected officials during this dynamic period in Muncie's history. Visitors can look over the Recent Additions area or perform a specific search. [KMG

369

Raptors in the City  

NSDL National Science Digital Library

This new Web site from the nonprofit educational program Raptors in the City was developed to enhance inner city kids' use of technology and connection with nature. Appropriate for all types of students, the site focuses on the Peregrine Falcon, a species previously on the brink of extinction, but, through population recovery efforts on many downtown skyscrapers, has become an endangered species success story. Students are able to navigate through the entire 2002 courtship and nesting story of a pair of falcons nesting on a skyscraper in Cleveland, Ohio, and view images of the birds in their nest. Additionally, the site includes a link to a live falcon cam and describes additional educational curricula that can be purchased from Mindfull Publishing.

370

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.

371

CEOs for Cities  

NSDL National Science Digital Library

The past few years have seen a growing number of organizations, institutions, and national think tanks express an increasing concern for sustaining the competitive economic advantage of major urban areas. One such group is CEOS for Cities, which is a national bipartisan alliance of mayors, corporate executives, university presidents, and other nonprofit leaders whose primary directive is to advance the economic competitiveness of cities. The group's executive committee includes such powerful leaders as Mayor Richard M. Daley of Chicago and Paul S. Grogan, the CEO of the Boston Foundation. One of the site's best features is the Trends and Data Analysis Reports, coupled with the Best Practice reports. Many of these documents are co-authored with other like-minded institutions, such as the Brookings Institution, and delve into such topics as What the IT Revolution Means for Regional Economic Development and Leveraging Colleges and Universities for Urban Economic Revitalization: An Action Agenda.

372

Martian City Map  

NASA Technical Reports Server (NTRS)

30 May 2004 Seasonal frost can enhance the view from orbit of polar polygonal patterns on the surface of Mars. Sometimes these patterns look something like a city map, or the view from above a city lit-up at night. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows an example from the south polar region near 80.7oS, 70.6oW. Polar polygons on Mars are generally believed, though not proven, to be the result of freeze/thaw cycles of ice occurring within the upper few meters (several yards) of the martian subsurface. The image shown here covers an area about 3 km (1.9 mi) across; sunlight illuminates the scene from the upper left.

2004-01-01

373

City 2.0  

NSDL National Science Digital Library

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.

2012-01-01

374

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.

2002-01-01

375

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.

376

The Inner City 100 (2001)  

NSDL National Science Digital Library

New from Inc.com and the Initiative for a Competitive Inner City, the Inner City 100 highlights 100 of the fastest growing urban businesses in the US. According to Michael Porter, Harvard Business School professor and founder of the Initiative for a Competitive Inner City, "When we started this, I thought we could reverse a lot of bad policies and bad perceptions that have prevented the inner cities from having a place in the economy. I never dreamed the inner city would become a window onto the future of the economy." Along with the listings, this site contains several articles on a variety of related topics including a story on Ahead Headgear, a hat embroiderer in New Bedford, MA rated number one in the Inner City 100; the Inner City 100 Almanac for information about the businesses that made the survey; as well as an article on comeback markets.

377

Florida: Columbia Restaurant in Ybor City  

Microsoft Academic Search

Known for its Latin flare, Tampa’s Ybor City is one of the highlights for tourists visiting the city. Located northeast of downtown, this historic city was founded by a large number of cigar manufacturers. With red brick buildings, iron balconies, and narrow brick streets, the city was created in a uniform style. Pictured is one of the city’s most popular

Chet Smolski

1978-01-01

378

Large cities are less green  

NASA Astrophysics Data System (ADS)

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.

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

2014-02-01

379

Source apportionment of fine particulate matter in Phoenix, AZ, using positive matrix factorization  

SciTech Connect

Speciated particulate matter PM2.5 data collected as Part. of the Interagency Monitoring of Protected Visual Environments (IMPROVE) program in Phoenix, AZ, from April 2001 through October 2003 were analyzed using the multivariate receptor model, positive matrix factorization (PMF). Over 250 samples and 24 species were used, including the organic carbon and elemental carbon analytical temperature fractions from the thermal optical reflectance method. A two-step approach was used. First, the species excluding the carbon fractions were used, and initially eight factors were identified; non-soil potassium was calculated and included to better refine the burning factor. Next, the mass associated with the burning factor was removed, and the data set rerun with the carbon fractions. Results were very similar (i.e., within a few percent), but this step enabled a separation of the mobile factor into gasoline and diesel vehicle emissions. The identified factors were burning (on average 2% of the mass), secondary transport (7%), regional power generation (13%), dust (25%), nitrate (9%), industrial As/Pb/Se (2%), Cu/Ni/V (7%), diesel (9%), and general mobile (26%). Most of the long-range transport of emissions emanates from south of Phoenix in Southeastern Arizona, West Texas, and Mexico, which are significant source regions of SO{sub 2} emissions from coal- and oil-fired power plants. The overall contribution from mobile sources also increased, as some mass (OC and nitrate) from the nitrate and regional power generation factors were apportioned with the mobile factors. This approach allowed better apportionment of carbon as well as total mass. Additionally, the use of multiple supporting analyses, including air mass trajectories, activity trends, and emission inventory information, helped increase confidence in factor identification. 86 refs., 10 figs., 2 tabs.

Steven G. Brown; Anna Frankel; Sean M. Raffuse; Paul T. Roberts; Hilary R. Hafner; Darcy J. Anderson [Sonoma Technology, Inc., Petaluma, CA (United States)

2007-06-15

380

Hot Tensile Deformation Characteristics and Processing Map of Extruded AZ80 Mg Alloys  

NASA Astrophysics Data System (ADS)

The hot deformation behaviors of extruded AZ80 Mg alloys were investigated using tension tests. True stress-true strain curves were obtained for deformation at temperatures from 250 to 450 °C with the strain rate range from 0.001 to 0.08 s-1. Optical microscopy analysis was performed to correlate microstructural changes to the flow behaviors. Based on the flow stress, the processing map at a strain of 0.18 was developed using the dynamic materials model theory and can be divided into three zones, including stability zones, change-over region, and instability zones. In stability zones, there are two dynamic recrystallization regions: one region with a peak efficiency of 58% at 350 °C and a strain rate of 0.001 s-1 called domain I; another region with a peak efficiency of 58% at 400 °C and a strain rate of 0.01 s-1 taken as domain II. The apparent activation energy for domain I was estimated to be 100.71 kJ/mol, indicating that short-circuit diffusion process is along the grain boundaries and falls at lower temperatures and lower strain rates. A lattice self-diffusion is considered to be rate controlling mechanism with the apparent activation energy estimated as 140.32 kJ/mol at higher temperatures and higher strain rates in domain II. The change-over region is the zone from domain I to domain II, in which the grains abnormally grow. In instability zones, twins, local deformation band, wedge cracking, and matrix cracking were observed, suggesting that these processing parameters for hot tension in this zone are inapplicable.

Lou, Yan; Chen, Heng; Ke, Changxing; Long, Min

2014-05-01

381

Hot Tensile Deformation Characteristics and Processing Map of Extruded AZ80 Mg Alloys  

NASA Astrophysics Data System (ADS)

The hot deformation behaviors of extruded AZ80 Mg alloys were investigated using tension tests. True stress-true strain curves were obtained for deformation at temperatures from 250 to 450 °C with the strain rate range from 0.001 to 0.08 s-1. Optical microscopy analysis was performed to correlate microstructural changes to the flow behaviors. Based on the flow stress, the processing map at a strain of 0.18 was developed using the dynamic materials model theory and can be divided into three zones, including stability zones, change-over region, and instability zones. In stability zones, there are two dynamic recrystallization regions: one region with a peak efficiency of 58% at 350 °C and a strain rate of 0.001 s-1 called domain I; another region with a peak efficiency of 58% at 400 °C and a strain rate of 0.01 s-1 taken as domain II. The apparent activation energy for domain I was estimated to be 100.71 kJ/mol, indicating that short-circuit diffusion process is along the grain boundaries and falls at lower temperatures and lower strain rates. A lattice self-diffusion is considered to be rate controlling mechanism with the apparent activation energy estimated as 140.32 kJ/mol at higher temperatures and higher strain rates in domain II. The change-over region is the zone from domain I to domain II, in which the grains abnormally grow. In instability zones, twins, local deformation band, wedge cracking, and matrix cracking were observed, suggesting that these processing parameters for hot tension in this zone are inapplicable.

Lou, Yan; Chen, Heng; Ke, Changxing; Long, Min

2014-03-01

382

Filtration, Washing, and Caustic Leaching of Hanford Tank AZ-101 Sludge  

SciTech Connect

The world’s largest vitrification facility is being designed and constructed at the U.S. Department of Energy’s Hanford Site, near Richland, Washington to convert radioactive waste stored in underground tanks into glass. Flow sheets call for washing and caustic leaching to pretreat the Hanford Envelope D sludge before it undergoes high-level waste (HLW) vitrification. These pretreatment steps reduce the quantity of HLW generated, by removing components that are soluble in water or caustic solutions, and often limit the waste loading in the glass. Crossflow filtration is specified to separate the wash and leach solutions from the solids. In crossflow filtration, the majority of the filter cake is swept away by the fluid flowing across it. Approximately 4313 g of slurry from Hanford Tank AZ-101 were evaluated by the pretreatment processes of crossflow filtration, washing, caustic leaching, and rinsing. The filterability was measured with a 0.1-mm sintered metal filter using a single-element, crossflow filtration system. Permeate flux of the as-received and washed slurries decayed linearly with the log of the undissolved solids concentration. The permeate flux of these slurries was also shown to be inversely proportional to the permeate viscosity. Statistical analysis indicated that the permeate flux of an 8-wt% insoluble solids slurry was also dependent on transmembrane pressure. As the slurry was concentrated to 18-wt%, the flux was dependent on axial velocity, with little dependency on transmembrane pressure. Samples of permeate from each wash were analyzed for chemical and radiochemical constituents. Primary component removal during the washing and leaching steps are discussed. This work provides important confirmation that the pretreatment of Hanford Envelope D wastes will have acceptable filterability and component removal during the pretreatment steps specified.

Geeting, John GH; Hallen, Richard T.

2005-02-15

383

Plastic Deformation Characteristics Of AZ31 Magnesium Alloy Sheets At Elevated Temperature  

NASA Astrophysics Data System (ADS)

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.

Park, Jingee; Lee, Jongshin; You, Bongsun; Choi, Seogou; Kim, Youngsuk

2007-05-01

384

Securing water for the cities.  

PubMed

Many cities in developing countries have grown so much that they can no longer provide adequate, sustainable water. Over pumping in Dakar and Mexico City has forced those cities to obtain water from ever more distant sources. In Dakar, the result has been saltwater intrusion. Overpumping has caused Mexico City to sink, in some areas by as much as 9 m, resulting in serious damage to buildings and sewage and drainage pipes. Other cities facing similar water problems are coastal cities in Peru (e.g., Lima), La Rioja and Catamarca in Argentina, cities in Northern Mexico, and cities in dry areas of Africa. For some cities, the problem is not so much ever more distant water supplies but insufficient funds to expand supplies. Bangkok and Jakarta both face saltwater intrusion into their overdrawn aquifers. Even through agriculture is the dominant user of water in most countries, demand concentrated in a small area exhausts local and regional sources and pollutes rivers, lakes, and coasts with untreated human and industrial waste. Most cities in Africa and Asia do not have a sewerage system. Further, most cities do not have the drains to deal with storm water and external floodwater, causing frequent, seasonal flooding. The resulting stagnant water provides breeding grounds for insect vectors of diseases (e.g., malaria). The problems in most cities are a result of poor management, not lack of water. Reducing leaks in existing piped distribution systems from the usual 60% loss of water to leaks to 12% would increase the available water 2-fold. Another way to address water shortages would be commercial, industrial, and recreational use of minimally treated waste water, such as is the case in Madras and Mexico City. Political solutions are needed to resolve inadequate water supply and waste management. PMID:12287008

Satterthwaite, D

1993-01-01

385

CityGML-Interoperable Access to 3D City Models  

Microsoft Academic Search

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

T. H. Kolbe

2005-01-01

386

CityGML - Interoperable Access to 3D City Models  

Microsoft Academic Search

Virtual 3D city models provide important information for differ- ent aspects of disaster management. In this context, up-to-dateness of and flexible access to 3D city models are of utmost importance. Spatial Data In- frastructures (SDI) provide the appropriate framework to cover both as- pects, integrating distributed data sources on demand. In this paper we pre- sent CityGML, a multi-purpose and

Thomas H. Kolbe; Gerhard Gröger; Lutz Plümer

387

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).

388

CityGML - Interoperable semantic 3D city models  

NASA Astrophysics Data System (ADS)

CityGML is the international standard of the Open Geospatial Consortium (OGC) for the representation and exchange of 3D city models. It defines the three-dimensional geometry, topology, semantics and appearance of the most relevant topographic objects in urban or regional contexts. These definitions are provided in different, well-defined Levels-of-Detail (multiresolution model). The focus of CityGML is on the semantical aspects of 3D city models, its structures, taxonomies and aggregations, allowing users to employ virtual 3D city models for advanced analysis and visualization tasks in a variety of application domains such as urban planning, indoor/outdoor pedestrian navigation, environmental simulations, cultural heritage, or facility management. This is in contrast to purely geometrical/graphical models such as KML, VRML, or X3D, which do not provide sufficient semantics. CityGML is based on the Geography Markup Language (GML), which provides a standardized geometry model. Due to this model and its well-defined semantics and structures, CityGML facilitates interoperable data exchange in the context of geo web services and spatial data infrastructures. Since its standardization in 2008, CityGML has become used on a worldwide scale: tools from notable companies in the geospatial field provide CityGML interfaces. Many applications and projects use this standard. CityGML is also having a strong impact on science: numerous approaches use CityGML, particularly its semantics, for disaster management, emergency responses, or energy-related applications as well as for visualizations, or they contribute to CityGML, improving its consistency and validity, or use CityGML, particularly its different Levels-of-Detail, as a source or target for generalizations. This paper gives an overview of CityGML, its underlying concepts, its Levels-of-Detail, how to extend it, its applications, its likely future development, and the role it plays in scientific research. Furthermore, its relationship to other standards from the fields of computer graphics and computer-aided architectural design and to the prospective INSPIRE model are discussed, as well as the impact CityGML has and is having on the software industry, on applications of 3D city models, and on science generally.

Gröger, Gerhard; Plümer, Lutz

2012-07-01

389

Global regulation of H2A.Z localization by the INO80 chromatin remodeling enzyme is essential for genome integrity  

PubMed Central

Summary INO80 is an evolutionarily conserved, ATP-dependent chromatin remodeling enzyme that plays roles in transcription, DNA repair, and replication. Here, we show that yeast INO80 facilitates these diverse processes at least in part by controlling genome-wide distribution of the histone variant H2A.Z. In the absence of INO80, H2A.Z nucleosomes are mis-localized, and H2A.Z levels at promoters show reduced responsiveness to transcriptional changes, suggesting that INO80 controls H2A.Z dynamics. Additionally, we demonstrate that INO80 has a novel histone exchange activity in which the enzyme can replace nucleosomal H2A.Z/H2B with free H2A/H2B dimers. Genetic interactions between ino80 and htz1 support a model in which INO80 catalyzes the removal of unacetylated H2A.Z from chromatin as a novel mechanism to promote genome stability.

Papamichos-Chronakis, Manolis; Watanabe, Shinya; Rando, Oliver J.; Peterson, Craig L.

2010-01-01

390

The dynamics of city formation*  

PubMed Central

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.

Henderson, J. Vernon; Venables, Anthony J.

2013-01-01

391

Sandstones, glaciers, burrows and transgressions: The Lower Palaeozoic of Jabel az-Zalmah, Al Kufrah Basin, Libya  

NASA Astrophysics Data System (ADS)

Field studies in the Jabel az-Zalmah region, at the northern flank of Al Kufrah Basin provide new insights into the stratigraphy and evolving depositional environments of Cambro-Ordovician through Devonian sediments. At the base of the succession, the Hawaz Formation is about 300 m thick and is characterised by frequently Skolithos-burrowed, fine to medium grained sandstones with occasional silty intervals and rare conglomerates deposited in a generally high-energy tidal shelf setting. Bioturbation is pervasive, and includes spectacular Cruziana traces produced by Early to Mid Ordovician trilobites at the bottom and the top of the Hawaz Formation respectively. These strata were incised during the late Ordovician (Hirnantian) glaciation. Ice sheets flowing over Jabel az-Zalmah cut a palaeo-topography of up to 100 m relief. This relief is overlain by a coarsening upward succession of clastic sedimentary rocks, recording re-advance of an ice sheet, which overrode the uppermost sandstones. Ice sheet retreat was accompanied by marine transgression and erosion, which left a thin transgressive lag-conglomerate, capped sharply by siltstones of the Tannezuft Formation. Progradation resumed after post-glacial maximum flooding, depositing tide, storm, and river-influenced parasequences of a major delta complex (200 m thick Acacus Formation). Fluvial incision, and the development of a disconformity, preceded the deposition of the Tadrart Formation (50 m thick), a succession of trough-cross bedded braided river deposits. Transgression, and the re-establishment of shallow or marginal marine systems, is represented by the extensively bioturbated Binem Formation in which Zoophycos burrows offer a tentative Middle Devonian stratigraphic fix. An understanding of the lithological character of the Lower Palaeozoic strata in Jabel az-Zalmah, together with the character of unconformities that punctuate the succession, will be vital for successful hydrocarbon exploration in this frontier basin which has, until now, been unsuccessful.

Le Heron, Daniel Paul; Howard, James P.

2012-03-01

392

Visualizing Software Systems as Cities  

Microsoft Academic Search

This paper presents a 3D visualization approach which gravitates around the city metaphor, i.e., an object-oriented software system is represented as a city that can be tra- versed and interacted with: the goal is to give the viewer a sense of locality to ease program comprehension. The key point in conceiving a realistic software city is to map the information

Richard Wettel; Michele Lanza

2007-01-01

393

Sioux City History  

NSDL National Science Digital Library

The Sioux City History website is billed as "your link to the past", and it does not fail to deliver on this promise. The site offers up snippets of the town's past, drawing on historic photographs, oral histories, and other documents. On the homepage, visitors will note eight primary sections, such as "Notable People", "Transportation", and "Arts & Leisure". First-time visitors should click on the "Arts & Leisure" area to start their journey. Here they will find essays and images that tell the stories of Riverside Park, community theatre, and the local legends who performed in the Monahan Post Band after World War I. To gain a better understanding of the role played by corn in local history and culture, visitors shouldn't miss the "Corn Palace" area. It's a tribute to the five grand corn palaces that graced the city from 1887 to 1891 as a symbol of agricultural prominence and boosterism. Finally, visitors can also look over a selection of oral histories and make use of the search engine here.

394

City/Place Population Estimates  

NSDL National Science Digital Library

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).

1997-01-01

395

Diffusion Bonding Behavior and Characterization of Joints Made Between 316L Stainless Steel Alloy and AZ31 Magnesium Alloy  

NASA Astrophysics Data System (ADS)

The 316L austenitic stainless steel and AZ31 magnesium alloy have physical and mechanical properties which makes these alloys suitable in a number of high technology based industries such as the aerospace and automotive sectors. However, for these alloys to be used in engineering applications, components must be fabricated and joined successfully. The differences in the physical and metallurgical properties between these two alloys prevents the use of conventional fusion welding processes commonly employed in aerospace and transport industry. Therefore, alternative techniques need to be developed and diffusion bonding technology is a process that has considerable potential to join these two dissimilar alloys. In this research work both solid-state and transient liquid phase (TLP) bonding processes were applied. The solid-state bonding of 316L steel to AZ31 magnesium alloy was possible at a bonding temperature of 550°C for 120 minutes using a pressure of 1.3 MPa. The interface characterization of the joint showed a thin intermetallic zone rich in Fe-Al was responsible for providing a metallurgical bond. However, low joint shear strengths were recorded and this was attributed to the poor surface to surface contact. The macro-deformation of the AZ31 alloy prevented the use of higher bonding pressures and longer bonding times. In order to overcome these problems, the TLP bonding process was implemented using pure Cu and Ni foils as interlayers which produced a eutectic phase at the bonding temperature. This research identified the bonding mechanism through microstructural and differential scanning calorimetry investigations. The microstructural characterization of the TLP joints identified intermetallics which became concentrated along the 316L steel/AZ31 bond interface due to the "pushing effect" of the solid/liquid interface during isothermal solidification stage of bonding. The size and concentration of the intermetallics had a noticeable effect on the final joint strength properties. TLP bonding using electrodeposited coatings of Cu and Ni were used as a way of controlling the volume of eutectic liquid formed at the joint. Theoretical and experimental work showed that the use of thin coatings was successful in reducing the size and amount of intermetallics formed at the joint and this had the effect on increasing joint shear strength values.

Elthalabawy, Waled Mohamed

396

On the System of Diophantine Equations x2 - 6y2 = -5 and x = az2 - b  

PubMed Central

Mignotte and Pethö used the Siegel-Baker method to find all the integral solutions (x, y, z) of the system of Diophantine equations x2 ? 6y2 = ?5 and x = 2z2 ? 1. In this paper, we extend this result and put forward a generalized method which can completely solve the family of systems of Diophantine equations x2 ? 6y2 = ?5 and x = az2 ? b for each pair of integral parameters a, b. The proof utilizes algebraic number theory and p-adic analysis which successfully avoid discussing the class number and factoring the ideals.

Zhang, Silan; Chen, Jianhua; Hu, Hao

2014-01-01

397

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

NASA Astrophysics Data System (ADS)

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.

Lin, Pengyu; Zhang, Zhihui; Ren, Luquan

2014-08-01

398

Tribological properties of the AZ91D magnesium alloy hardened with silicon carbide and by severe plastic deformation  

Microsoft Academic Search

Results of investigation of the tribological contact characteristics of R18 tool steel in interface with AZ91D magnesium alloy\\u000a hardened with SiC disperse powder filler and by severe plastic deformation (SPD)—specifically, equal-channel angular pressing\\u000a (ECAP)—are presented. It is established that introduction of the SiC powder filler into the magnesium alloy increases the\\u000a friction coefficient and reduces the wear rate. The size

V. I. Semenov; Y.-R. Jeng; S.-J. Huang; Y.-Zh. Dao; S.-J. Hwang; L. Sh. Shuster; S. V. Chertovskikh; P.-Ch. Lin

2009-01-01

399

Complete Mitochondrial and Plastid Genomes of the Green Microalga Trebouxiophyceae sp. Strain MX-AZ01 Isolated from a Highly Acidic Geothermal Lake  

PubMed Central

We report the complete organelle genome sequences of Trebouxiophyceae sp. strain MX-AZ01, an acidophilic green microalga isolated from a geothermal field in Mexico. This eukaryote has the remarkable ability to thrive in a particular shallow lake with emerging hot springs at the bottom, extremely low pH, and toxic heavy metal concentrations. Trebouxiophyceae sp. MX-AZ01 represents one of few described photosynthetic eukaryotes living in such a hostile environment. The organelle genomes of Trebouxiophyceae sp. MX-AZ01 are remarkable. The plastid genome sequence currently presents the highest G+C content for a trebouxiophyte. The mitochondrial genome sequence is the largest reported to date for the Trebouxiophyceae class of green algae. The analysis of the genome sequences presented here provides insight into the evolution of organelle genomes of trebouxiophytes and green algae.

Martinez-Romero, Esperanza

2012-01-01

400

Salt Lake City, Utah  

NASA Technical Reports Server (NTRS)

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

2001-01-01

401

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

PubMed Central

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.

2004-01-01

402

Pre-clinical validation of a novel alpha-7 nicotinic receptor radiotracer, [(3)H]AZ11637326: target localization, biodistribution and ligand occupancy in the rat brain.  

PubMed

The alpha-7 neuronal nicotinic receptor is a novel pharmacological target for psychiatric and cognitive disorders. Selective radiotracer tools for pre-clinical receptor occupancy can facilitate the interpretation of the biological actions of small molecules at a target receptor. We discovered a high affinity nicotinic alpha-7 subtype-selective ligand, AZ11637326, with physical-chemical and pharmacokinetic properties suitable for an in vivo radioligand tool. [(3)H]AZ11637326 synthesis by tritiodehalogenation of the corresponding tribromide precursor yielded a high specific activity radiotracer with high affinity alpha-7 receptor binding in the rat hippocampus determined by autoradiography (Kd = 0.2 nM). When [(3)H]AZ11637326 was administered to rats by intravenous bolus, rapid uptake was measured in the brain followed by a 3-4 fold greater specific binding in regions containing the alpha-7 receptor (frontal cortex, hippocampus, hypothalamus and midbrain) when compared to non-target regions (striatum and cerebellum). Systemic administration of the high affinity alpha-7 receptor antagonist, methyllycaconitine (MLA), or pretreatment with alpha-7 selective agonists (AR-R17779, PyrQTC, DBCO-4-POM, and DBCO-3-POM) significantly blocked the alpha-7 specific binding of [(3)H]AZ11637326 in the rat brain. The rank order of ligand ED(50) values for in vivo alpha-7 receptor occupancy in rat hippocampus was: DBCO-4-POM > DBCO-3-POM ? MLA > PyrQTC > AR-R17779. The occupancy affinity shift was consistent with in vitro binding affinity in autoradiography. Our studies established the optimal conditions for [(3)H]AZ11637326 in vivo specific binding in the rat brain and support the use of [(3)H]AZ11637326 as a pre-clinical tool for assessment of novel alpha-7 compounds in drug discovery. PMID:21497612

Maier, Donna L; Hill, Geraldine; Ding, Min; Tuke, David; Einstein, Emily; Gurley, David; Gordon, John C; Bock, Mary J; Smith, Jeff S; Bialecki, Russell; Eisman, Mark; Elmore, Charles S; Werkheiser, Jennifer L

2011-01-01

403

Source-zone characterization of a chlorinated-solvent contaminated Superfund site in Tucson, AZ  

NASA Astrophysics Data System (ADS)

An extensive site-characterization project was conducted at a large chlorinated-solvent contaminated Superfund site in Tucson, AZ. The project consisted of several components, including traditional site-characterization activities, tracer tests, laboratory experiments conducted with core material collected from the site, and mathematical modeling. The primary focus of the work presented herein is the analysis of induced-gradient contaminant elution tests conducted in a source zone at the site, investigation of the potential occurrence of immiscible liquid in the saturated zone, characterization of the relationship between mass flux reduction and mass removal, and evaluation of the impact of source-zone management on site remediation. The results of the present study, along with those of prior work, indicate that immiscible liquid is likely present in the saturated zone at the site source zones. Extensive tailing and rebound was observed for the contaminant-elution tests, indicating nonideal transport and mass-transfer behavior. The elution data were analyzed with a source-zone-scale mathematical model, and the results indicated that nonideal immiscible-liquid dissolution was the primary cause of the observed behavior. The time-continuous relationship between mass flux reduction and mass removal associated with the plume-scale pump-and-treat operation exhibited an initial large drop in mass flux with minimal mass removed, followed by a period of minimal mass flux reduction and a second period of large reduction. This behavior reflects the impact of both source-zone and aqueous-plume mass removal dynamics. Ultimately, a greater than 90% reduction in mass flux was achieved for a mass removal of approximately 50%. The influence of source-zone management on site remediation was evaluated by conducting two predictive simulations, one for which the source zones were controlled and one for which they were not. A plume-scale model was used to simulate the composite contaminant concentrations associated with groundwater extracted with the pump-and-treat system, which were compared to measured data. The information generated from this study was used to enhance the site conceptual model, help optimize operation of the pump-and-treat system, and evaluate the utility of source-zone remediation.

Brusseau, M. L.; Nelson, N. T.; Zhang, Z.; Blue, J. E.; Rohrer, J.; Allen, T.

2007-02-01

404

A study of deformation twinning in magnesium alloy AZ31B  

NASA Astrophysics Data System (ADS)

Crystals with a hexagonal close-packed crystal structure are inherently anisotropic, and have a limited number of independent slip systems, which lead to strong deformation textures and reduced formability in polycrystalline products. In magnesium (Mg), all of the easy slip systems have a Burgers vector in the direction making twinning necessary for arbitrary shape changes. The most common twinning system which allows extension along the c-axis is {1012}<1011>. A good predictor of slip is the global Schmid factor, which resolves the externally applied force onto the slip plane and direction of a crystal. The critically resolved shear stress (CRSS) at which a grain twins is not readily measured by experiment and the CRSS for twin initiation often appears larger than for twin propagation. In polycrystals, twin variants with both low and high Schmid factors have been observed indicating that this Schmid factor is inappropriate to predict twinning and more local effects play an important, though still uncertain role. In this work, experiments were devised to dynamically study extension twinning in a polycrystalline Mg alloy AZ31B with a strong basal rolling texture by tensile deformation parallel to the plate normal. Three-dimensional X-ray diffraction using a synchrotron source was used to map the centre-of-mass positions, orientations, and grain-resolved elastic strain tensors of over 1000 grains in-situ up to a true strain of 1.4%. The majority of twins formed in grains with a high local Schmid factor; however, low-ranked twin variants were common. The average grain-resolved stress did not always select the highest twin variant and resulted in some negative Schmid factors. The internal stress state of parent grains and twinned grains did not differ significantly within the large measurement uncertainties. The misorientations between grains ideally oriented for twinning and their nearest neighbours could not explain cases of no twin activity. Results suggest that the controlling factors for twin formation are much more local and not captured within the spatial resolution of the technique. Complimentary measurement of the strain rate sensitivity during twinning, by instantaneous strain rate change tests, suggest that basal slip is a part of this local process.

Majkut, Marta

405

Safe in the city.  

PubMed

Workplace danger and violence are complex problems that affect nurses more often than is recognized. The home healthcare work environment is challenging enough without the additional risks associated with working out in the open or within a client's home. Every clinician working in home health today understands the demands of visits or extended care in the home and often reluctantly accepts the involved risk. The clinician working in the rural setting may experience similar challenges, but in large metropolitan cities, it has become increasingly frightening as crime, drug use, gangs, violence, homelessness, and transportation issues have made the clinician's job much tougher. It is important to renew awareness and remind clinicians to maintain constant vigilance for personal safety. PMID:18849719

Anderson, Norma R

2008-10-01

406

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.

407

Formation and stability of organic acid monolayers on magnesium alloy AZ31: The role of alkyl chain length and head group chemistry  

NASA Astrophysics Data System (ADS)

Magnesium wrought alloy AZ31 has a 30% lower density than aluminum alloys and provides the opportunity to reduce vehicle weight and hence to reduce fuel consumption. Today, the use in industrial applications is limited due to low corrosion resistance. Carboxylic and phosphonic acids were investigated as promising alternatives for corrosion protection on AZ31 magnesium wrought alloy. Adsorption and orientation of organic monolayers were studied as a function of aliphatic chain lengths and head groups. As final result, the octadecylphosphonic acid led to a measureable lowering of the corrosion current density and inhibited the growth of the oxide film under humid conditions.

Szillies, S.; Thissen, P.; Tabatabai, D.; Feil, F.; Fürbeth, W.; Fink, N.; Grundmeier, G.

2013-10-01

408

76 FR 18753 - City of Springfield, Illinois, City Water, Light and Power; Notice of Filing  

Federal Register 2010, 2011, 2012, 2013

...Regulatory Commission [Docket No. EL11-31-000] City of Springfield, Illinois, City Water, Light and Power; Notice of Filing Take notice that on March 24, 2011, The City of Springfield, Illinois, City Water, Light and Power (CWLP),...

2011-04-05

409

Promoting tourism in US cities  

Microsoft Academic Search

Urban tourism is a relatively recent phenomenon but is now being embraced by most US cities, which are using substantial funds to compete for visitors, creating elaborate new infrastructures in the process. This article provides an analytical overview of the steps a variety of US cities are taking — such as developing a new brand image, refurbishing run-down areas, touting

Dennis R Judd

1995-01-01

410

Globalization: Countries, Cities and Multinationals  

Microsoft Academic Search

McCann P. and Acs Z. J. Globalization: countries, cities and multinationals, Regional Studies. This paper explores the relationship between the size of a country, the size of its cities, and the importance of economies of scale in the modern era of globalization. In order to do this, it integrates three different literatures, namely the literature on the optimal size of

Philip McCann; Zoltan J. Acs

2011-01-01

411

Planning for a City's Future  

NSDL National Science Digital Library

This lesson plan asks students to consider how knowledge of geography and history can help prepare for the future. Students will research the geography and history of a city and write reports explaining how city leaders can use this information to plan for the future.

412

Extreme Rainfall In A City  

Microsoft Academic Search

Cities contain many structures and activities that are vulnerable to severe weather. Heavy precipitation cause floods which can damage structures, compromise transportation and water supply systems, and slow down economic and social activities. Rain induced flood patterns in cities must be well understood to enable effective placement of flood control and other regulatory measures. The planning goal is not to

Lawrence Nkemdirim

2002-01-01

413

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.

414

Aerial view of a city  

NSDL National Science Digital Library

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.

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

2007-01-12

415

Smart Cities and Sustainability Models  

Microsoft Academic Search

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

Lorena BATAGAN

2011-01-01

416

Gallup Interactives: City Wellbeing Tracking  

NSDL National Science Digital Library

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.

Gallup

417

CHED Events: Salt Lake City  

NASA Astrophysics Data System (ADS)

The Division of Chemical Education (CHED) Committee meetings planned for the Spring 2009 ACS Meeting in Salt Lake City will be in the Marriott City Center Hotel. Check the location of other CHED events, the CHED Social Event, the Undergraduate Program, Sci-Mix, etc. because many will be in the Salt Palace Convention Center.

Wink, Donald J.

2009-03-01

418

The effect of high-intensity pulsed ion beam on surface structures of MAO film on magnesium alloy AZ31  

NASA Astrophysics Data System (ADS)

Micro-arc oxidation (MAO) films on AZ31 magnesium alloy were modified by high-intensity pulsed ion beam (HIPIB) irradiation with ion energy of 300 keV at 200 A/cm2 with up to 10 shots. Scanning electron microscopy, X-ray diffractometry and micro-hardness testers were used to characterize the surface properties of the irradiated MAO films. The thickness of remelted layer increased and then decreased, and the maximal value of 10 ?m was obtained at 200 A/cm2 with 5 shots. The phase structure of the ablated surface still consisted of Mg2SiO4 and MgO, which are the same as that of the original ones. Surface roughness of the ablated surface increased and then decreased with the increase of shot number. The surface roughness for the original MAO film is about 2.10 ?m, it decreased to 1.18 ?m with 1 shot irradiation and then increased to 4.13 ?m with irradiation shots up to 10. Correspondingly, the surface energy of the ablated surface augmented, resulting in the tedious decrease of static contact angle from 145.9° for original film to 49.7° for the film with 10 shots. The ablation modification enhanced the continuity and compaction of the MAO films on AZ31 magnesium alloy.

Han, X. G.; Zhu, F.; Zhu, X. P.; Lei, M. K.; Xu, J. J.

2013-07-01

419

Characterization and degradation behavior of AZ31 alloy surface modified by bone-like hydroxyapatite for implant applications  

NASA Astrophysics Data System (ADS)

Hydroxyapatite (HA) coating on AZ31 alloy substrate was prepared by a cathodic electrodeposition method. The as-deposited specimen was then post-treated with hot alkali solution to improve the corrosion resistance and bioactivity for implant applications. The microstructure and composition of HA coating, as well as its degradation behavior in simulated body fluid (SBF) were investigated. It reveals that the as-deposited coating consists of dicalcium phosphate dehydrate (DCPD, CaHPO 4ˇ2H 2O) and HA. While 10 ?m-thick nanowhisker HA coatings doped with Na +, Mg +, HPO 42-and CO 32- can be found after NaOH alkali treatment, which exhibits a very similar composition of natural bone. The post-treated coating was composed of needle-like particles with 1000 nm in length and 35 nm in diameter, having a slenderness ratio of about 28.6. Electrochemical tests shows that the Ecorr of Mg substrate significantly increased from -1.6 to -1.42 V after surface modified by HA coatings. There was obvious mass gain on post-treated specimen immersed in SBF during the first 30 days due to the Ca-P-Mg deposition. The HA-coated AZ31 alloy could slow down the degradation rate and effectively induce the deposition of Ca-P-Mg apatite in SBF, showing a good bioactivity.

Wen, Cuilian; Guan, Shaokang; Peng, Li; Ren, Chenxing; Wang, Xiang; Hu, Zhonghua

2009-04-01

420

Evaluating the Superplastic Flow of a Magnesium AZ31 Alloy Processed by Equal-Channel Angular Pressing  

NASA Astrophysics Data System (ADS)

Experiments show that the magnesium AZ31 (Mg-3 pct Al-1 pct Zn) alloy exhibits excellent superplastic properties at 623 K (350 °C) after processing by equal-channel angular pressing using a die with a channel angle of 135 deg and a range of decreasing processing temperatures from 473 K to 413 K (200 °C to 140 °C). A maximum elongation to failure of ~1200 pct was achieved in this alloy at a tensile strain rate of 1.0 × 10-4 s-1. Microstructural inspection showed evidence for cavity formation and grain growth during tensile testing with the grain growth leading to significant strain hardening. An examination of the experimental data shows that grain boundary sliding is dominant during superplastic flow. Furthermore, a comprehensive review of the present results and extensive published data for the AZ31 alloy shows the exponent of the inverse grain size is given by p ? 2 which is consistent with grain boundary sliding as the rate-controlling flow mechanism.

Figueiredo, Roberto B.; Langdon, Terence G.

2014-07-01

421

Poly(L-lactic acid)/hydroxyapatite/collagen composite coatings on AZ31 magnesium alloy for biomedical application.  

PubMed

Surface modification of biomedical magnesium alloy using composite coating shows an attemptable approach for the development of Mg-based biomaterials with excellent cytocompatibility. Hydroxyapatite/collagen composite was preliminarily fabricated by biomineralization, the bioactive poly(l-lactic acid)/hydroxyapatite/collagen composite coatings were spin coated on AZ31 magnesium alloy using poly(l-lactic acid) solution mixed with hydroxyapatite/collagen particles, and the resultant materials and coatings were characterized in structure and related properties; furthermore, the in vitro degradation behavior of modified magnesium alloy in 1.5-fold Hank's solution was investigated. The results show that hydroxyapatite/collagen composite achieved chemical bonding between hydroxyapatite and collagen similar to natural bone; composite coatings on AZ31 magnesium alloy retained the bioactive functional groups of the componential materials and improved the corrosion resistance of Mg alloy; the mass fraction of hydroxyapatite/collagen particles incorporated into the composite affected the porous structure, interfacial adhesion and thus the corrosion resistance of the composite coating due to phase separation as well as volume concentration effects of polymer solution. Composite coatings suppressed the sharp rising of pH value and the released Mg(2+) from substrate to extensive degree, and the degradation behavior of the modified magnesium alloy was supposed to be correlated to microstructure of the coating as well as the synergistic reactions among alkaline- and acidic-degraded products. PMID:23851659

Wang, Zhen-Lin; Yan, Yu-Hua; Wan, Tao; Yang, Hui

2013-10-01

422

Corrosion protection and improved cytocompatibility of biodegradable polymeric layer-by-layer coatings on AZ31 magnesium alloys.  

PubMed

Composite coatings of electrostatically assembled layer-by-layer anionic and cationic polymers combined with an Mg(OH)2 surface treatment serve to provide a protective coating on AZ31 magnesium alloy substrates. These ceramic conversion coating and layer-by-layer polymeric coating combinations reduced the initial and long-term corrosion progression of the AZ31 alloy. X-ray diffraction and Fourier transform infrared spectroscopy confirmed the successful application of coatings. Potentiostatic polarization tests indicate improved initial corrosion resistance. Hydrogen evolution measurements over a 2 week period and magnesium ion levels over a 1 week period indicate longer range corrosion protection and retention of the Mg(OH)2 passivation layer in comparison to the uncoated substrates. Live/dead staining and DNA quantification were used as measures of biocompatibility and proliferation while actin staining and scanning electron microscopy were used to observe the cellular morphology and integration with the coated substrates. The coatings simultaneously provided improved biocompatibility, cellular adhesion and proliferation in comparison to the uncoated alloy surface utilizing both murine pre-osteoblast MC3T3 cells and human mesenchymal stem cells. The implementation of such coatings on magnesium alloy implants could serve to improve the corrosion resistance and cellular integration of these implants with the native tissue while delivering vital drugs or biological elements to the site of implantation. PMID:23684762

Ostrowski, Nicole; Lee, Boeun; Enick, Nathan; Carlson, Benjamin; Kunjukunju, Sangeetha; Roy, Abhijit; Kumta, Prashant N

2013-11-01

423

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

NASA Astrophysics Data System (ADS)

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.

Mancini, Dario; Brescia, Massimo; Spirito, Gianfranco

1998-05-01

424

Electrochemical characteristics of calcium-phosphatized AZ31 magnesium alloy in 0.9 % NaCl solution.  

PubMed

Magnesium alloys suffer from their high reactivity in common environments. Protective layers are widely created on the surface of magnesium alloys to improve their corrosion resistance. This article evaluates the influence of a calcium-phosphate layer on the electrochemical characteristics of AZ31 magnesium alloy in 0.9 % NaCl solution. The calcium phosphate (CaP) layer was electrochemically deposited in a solution containing 0.1 M Ca(NO3)2, 0.06 M NH4H2PO4 and 10 ml l(-1) of H2O2. The formed surface layer was composed mainly of brushite [(dicalcium phosphate dihidrate (DCPD)] as proved by energy-dispersive X-ray analysis. The surface morphology was observed by scanning electron microscopy. Immersion test was performed in order to observe degradation of the calcium phosphatized surfaces. The influence of the phosphate layer on the electrochemical characteristics of AZ31, in 0.9 % NaCl solution, was evaluated by potentiodynamic measurements and electrochemical impedance spectroscopy. The obtained results were analysed by the Tafel-extrapolation method and equivalent circuits method. The results showed that the polarization resistance of the DCPD-coated surface is about 25 times higher than that of non-coated surface. The CaP electro-deposition process increased the activation energy of corrosion process. PMID:24477876

Hadzima, Branislav; Mhaede, Mansour; Pastorek, Filip

2014-05-01

425

One-step synthesis of lamellar molybdate pillared hydrotalcite and its application for AZ31 Mg alloy protection  

NASA Astrophysics Data System (ADS)

A novel anticorrosion pigment for AZ31 Mg alloy protection, molybdate pillared hydrotalcite (HT-MoO 42-), was successfully fabricated via a simple one-step process. The physicochemical properties of the samples were well characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), Raman spectra, and inductively coupled plasma (ICP) method, respectively. The results indicated that the material showed typical characteristics of molybdate intercalated hydrotalcite. Additionally, it was found that the sample exhibited nano-sized lamellar morphology with the particle size of 35-60 nm. Moreover, the coating on AZ31 Mg alloy containing HT-MoO 42- pigment showed obviously higher corrosion protection performance in comparison with the strontium chromate (SC) pigment by Electrochemical impedance spectroscopy (EIS) measurements. The mechanism of corrosion protection was proposed to be that the HT-MoO 42- pigment in the coating would cause the pigment to undergo amphoteric ion exchange with aggressive NaCl solution, leading to the release of molybdate and Zn 2+ inhibitors.

Yu, Xiang; Wang, Jun; Zhang, Milin; Yang, Piaoping; Yang, Lihui; Cao, Dianxue; Li, Junqing

2009-02-01

426

Garden City Schools' Media Centers  

NSDL National Science Digital Library

Welcome to Garden City Public Schools Media Centers Web Pages. The Goal of the Garden City Public Schools' Media Centers is to provide access to information to students, staff, and community in both print and electronic formats. Our goal is to instill the importance of not only reading but also of information and technology literacy skills. High School Media Resource Center Media Specialist: Ms. Nancy Schultz-Speck; Librarian Paraprofessional: Mrs. Carol Garrett; 6500 Middlebelt Road, Garden City, MI 48135 (734) 762-8350 ext. 221 Email: schultn@gardencityschools.com MRC HOURS: 7am until 2:20pm - MRC Schedule Garden City Middle School Media Center Media Specialist:; 1851 Radcliff, Garden City, MI 48135 (734) 762-8400 District s Online Catalog - Destiny - Access the OPAC to ...

Schultz, Ms.

2007-03-26

427

Clean Cities Award Winning Coalition: Salt Lake City  

SciTech Connect

Since its designation as a national Clean City in 1994, Salt Lake Clean Cities has put more than 2,600 alternative fuel vehicles (AFVs) on community streets. The 82 business, nonprofit, and government agencies that comprise the coalition are all dedicated to cleaning the air by reducing vehicle exhaust. Salt Lake Clean Cities has the third largest compressed natural gas and propane-refueling infrastructure in the country, with 98 locations available. They sponsor an annual ''Spring Soiree'' to increase public awareness about the program and educate the public about the benefits of alternative fuel and AFVs.

ICF Kaiser

1999-05-20

428

Clean Cities Award Winning Coalition: Salt Lake City  

SciTech Connect

Since its designation as a national Clean City in 1994, Salt Lake Clean Cities has put more than 2,600 alternative fuel vehicles (AFVs) on community streets. The 82 business, nonprofit, and government agencies that comprise the coalition are all dedicated to cleaning the air by reducing vehicle exhaust. Salt Lake Clean Cities has the third largest compressed natural gas and propane-refueling infrastructure in the country, with 98 locations available. They sponsor an annual Spring Soiree to increase public awareness about the program and educate the public about the benefits of alternative fuel and AFVs.

ICF Kaiser.

1999-05-20

429

Great Zoom out of Tucson, AZ: The University of Arizona Football Stadium  

NSDL National Science Digital Library

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.

Shirah, Greg; Mitchell, Horace; Newcombe, Marte; Williams, Darrel

2001-09-06

430

Great Zoom into Tucson, AZ: The University of Arizona Football Stadium  

NSDL National Science Digital Library

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.

Shirah, Greg; Mitchell, Horace; Newcombe, Marte; Williams, Darrel

2001-09-06

431

Nature in the City  

NSDL National Science Digital Library

Nature in the City is a project of the Earth Island Institute, and is "wholly dedicated to ecological conservation, restoration and stewardship of the [San] Franciscan bioregion." Their website's "About" section gives a thorough explanation of not only their goals, as well as a definition of nature. Furthermore, this section provides some philosophical insight into what exactly "urban nature" happens to be. Those visitors interested in a more visceral tour of San Francisco should check out the "Photo Gallery" link, and they should be sure to check out the "Natural Areas" album to view some eerie-looking oak woodlands in Golden Gate Park. Additionally, visitors to the site who are interested in the life that teems on Alcatraz Island will enjoy file number fourteen which includes an image of roosting double-crested cormorants on a dramatic hillside. Finally the "Local Ecology" link has an explanation of the "Biodiversity Crisis" in San Francisco, which can be attributed to ecological, political, institutional, social and cultural factors.

432

City Stars: A Workshop for Inner City Teachers  

NASA Astrophysics Data System (ADS)

In 1994, Dr. Paul Gorenstein of the Harvard-Smithsonian Center for Astrophysics and The Charles Hayden Planetarium, Boston received a NASA AGSE grant to develop a special workshop for Boston-area inner city teachers with little, or no background in astronomy. The objective of these 3-hour workshops was to provide some practical classroom tools by which teachers may enhance the awareness and understanding of astronomy and space science among their students. Teachers received instruction on eight basic astronomy concepts and demonstrations of inexpensive hands-on astronomy activities for the classroom. Following the success of the 1994 City Stars teacher's workshops, Dr. Gorenstein and The Charles Hayden Planetarium, Boston received a NASA IDEA grant to conduct two additional City Stars workshops, held in October 1996. This paper will display the instructional materials we developed and highlight our experiences in presenting the City Stars workshops.

Grice, N.

1996-12-01

433

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.

434

Olympic Cities: Regeneration, City Rebranding and Changing Urban Agendas  

Microsoft Academic Search

Winning the right to host the Olympic Games is widely regarded as the most significant prize on offer in the never-ending contest between the world's leading cities for prestige and investment. This essay explores the implications and sig- nificance of being an Olympic city. After recognising the Olympics as a mega-event with inherent mega-project tendencies, it provides a chronological survey

John R. Gold; Margaret M. Gold

2008-01-01

435

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

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.

2013-01-01

436

Evaluating the improvement of corrosion residual strength by adding 1.0 wt.% yttrium into an AZ91D magnesium alloy  

SciTech Connect

The influence of yttrium on the corrosion residual strength of an AZ91D magnesium alloy was investigated detailedly. Scanning electron microscope was employed to analyze the microstructure and the fractography of the studied alloys. The microstructure of AZ91D magnesium alloy is remarkably refined due to the addition of yttrium. The electrochemical potentiodynamic polarization curve of the studied alloy was performed with a CHI 660b electrochemical station in the three-electrode system. The result reveals that yttrium significantly promotes the overall corrosion resistance of AZ91D magnesium alloy by suppressing the cathodic reaction in corrosion process. However, the nucleation and propagation of corrosion pits on the surface of the 1.0 wt.% Y modified AZ91D magnesium alloy indicate that pitting corrosion still emerges after the addition of yttrium. Furthermore, stress concentration caused by corrosion pits should be responsible for the drop of corrosion residual strength although the addition of yttrium remarkably weakens the effect of stress concentration at the tip of corrosion pits in loading process.

Wang Qiang [Key Laboratory of Automobile Materials (Jilin University), Ministry of Education, College of Materials Science and Engineering, Jilin University, Changchun, 130025 (China); Liu Yaohui, E-mail: liuyaohui2005@yahoo.com [Key Laboratory of Automobile Materials (Jilin University), Ministry of Education, College of Materials Science and Engineering, Jilin University, Changchun, 130025 (China); Fang Shijie [Department of Mechanical and Electrical Engineering, Luoyang Institute of Science and Technology, Luoyang 471023 (China); Song Yulai; Zhang Dawei; Zhang Lina; Li Chunfang [Key Laboratory of Automobile Materials (Jilin University), Ministry of Education, College of Materials Science and Engineering, Jilin University, Changchun, 130025 (China)

2010-06-15

437

The Role of Trans Tensional Structures and Lake Mead Reservoir in Groundwater Flow in Black Canyon, Lake Mead National Recreation Area, NV-AZ  

Microsoft Academic Search

Hot springs and seeps discharging into Black Canyon (BC) along the Colorado River in north Colorado River Valley (CRV) support endemic riparian ecosystems in the Lake Mead National Recreation Area. Increases in groundwater development in southern NV and northwestern AZ may impact spring discharge. Sources of spring discharge in BC were evaluated using geochemical methods. Kinematic analysis and geologic mapping

L. Justet; S. Beard

2010-01-01

438

Whole-Genome Sequences of Streptococcus tigurinus Type Strain AZ_3a and S. tigurinus 1366, a Strain Causing Prosthetic Joint Infection.  

PubMed

Streptococcus tigurinus, a novel member of the Streptococcus mitis group, was recently identified as a causative agent of invasive infections. We report the complete genome sequences of the S. tigurinus type strain AZ_3a and S. tigurinus strain 1366. The genome sequences assist in the characterization of virulence determinants of S. tigurinus. PMID:23640198

Gizard, Yann; Zbinden, Andrea; Schrenzel, Jacques; François, Patrice

2013-01-01

439

Effect of pre-tension amount on formation accuracy of AZ31 as-extruded profile in warm tension-rotation bending process  

NASA Astrophysics Data System (ADS)

A warm tension rotation bending process is presented to bend the AZ31 as-extruded profile. The effect of pretension amount on formation accuracy of bent AZ31 as-extruded profile was investigated by using numerical and experimental methods. A 3D elastic-plastic thermo-mechanical coupled finite element model of AZ31 profile in bending process was established and the bending experiments were carried out. The results indicate that pre-tension amounts increasing from 0.2% to 1.1%, the numerical and experimental springback angles of AZ31 bent profile all decrease, the experimental springback angles decrease from 12.5° to 9.8° the numerical and experimental bending radii all decrease, the experimental bending radii decrease from 95.60 mm to 92.83 mm; the distortion of cross-section increases, the sequencing of distortion levels is the thickness of outside-rib, the thickness of inside-rib, the width of outside of the profile, the width of inside of the profile and the thickness of middle-rib.

Xiao, Han; Zhang, Shi-hong; Liu, Jin-song; Cheng, Ming

2013-05-01

440

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

NASA Astrophysics Data System (ADS)

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.

Momose, Munetake; Hiramatsu, Masaaki; Tsukagoshi, Takashi; Shimajiri, Yoshito; Ikeda, Norio; Kitamura, Yoshimi; Kamegai, Kazuhisa; Ezawa, Hajime; Kawabe, Ryohei; Saito, Masao

2009-08-01

441

A study on the effect of plasma electrolytic oxidation on the stress corrosion cracking behaviour of a wrought AZ61 magnesium alloy and its friction stir weldment  

Microsoft Academic Search

Friction stir weldments of a wrought AZ61 magnesium alloy produced in a robotic friction stir welder under optimised welding conditions were characterised for microstructure, mechanical properties, corrosion and stress corrosion cracking (SCC) behaviour. The effect of surface modification in the form of a plasma electrolytic oxidation (PEO) coating on the corrosion behaviour of the weldment was assessed. The weldment exhibited

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

2009-01-01

442

Whole-Genome Sequences of Streptococcus tigurinus Type Strain AZ_3a and S. tigurinus 1366, a Strain Causing Prosthetic Joint Infection  

PubMed Central

Streptococcus tigurinus, a novel member of the Streptococcus mitis group, was recently identified as a causative agent of invasive infections. We report the complete genome sequences of the S. tigurinus type strain AZ_3a and S. tigurinus strain 1366. The genome sequences assist in the characterization of virulence determinants of S. tigurinus.

Gizard, Yann; Zbinden, Andrea; Schrenzel, Jacques

2013-01-01

443

Relation Between Crack Orientation and K/sub IC/ in the Aluminum Alloy A-Z5GU. A Microfractographic Study.  

National Technical Information Service (NTIS)

The critical value of the stress intensity factor K/sub IC/ or fracture toughness was measured for an aluminum alloy A-Z5GU (6% Zn, 2.4% Mg, 1.5% Cu) in the hardened-and-tempered state for the six principal orientations that the crack can have relative to...

P. Vigier

1973-01-01

444

Arsenic Removal from Drinking Water by Adsorptive Media - U.S. EPA Demonstration Project at Covered Wells in Tohono O?odham Nation, AZ - Final Performance Evaluation Report  

EPA Science Inventory

This report documents the activities performed and the results obtained from the arsenic removal treatment technology demonstration project at Covered Wells in Tohono O?odham Nation, AZ. The main objective of the project was to evaluate the effectiveness of AdEdge Technologies? ...

445

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

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.

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

446

Boundary element method predictions of the influence of the electrolyte on the galvanic corrosion of AZ91D coupled to steel  

Microsoft Academic Search

This research investigated the galvanic corrosion of the magnesium alloy AZ91D coupled to steel. The galvanic current distribution was measured in 5% NaCl solution, corrosive water and an auto coolant. The experimental measurements were compared with predictions from a Boundary Element Method (BEM) model. The boundary condition, required as an input into the BEM model, needs to be a polarization

Jimmy X. Jia; Guangling Song; Andrej Atrens

2005-01-01

447

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

PubMed

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

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

2013-06-01

448

Reflecticons: Trees of a City.  

ERIC Educational Resources Information Center

Describes a four week artist-in-residence program called "Reflecticons: Trees of a City." Using handmade paper, the children of Kaukauna (Wisconsin) explored the heritage, development, and growth of their community from the 1700s to the present. (CMK)

Hoglund, Paula Stevenson

1999-01-01

449

Organization of World Heritage Cities  

NSDL National Science Digital Library

Cities around the world have served as the primary repositories for human culture, innovation, and diversity for millennia, so it makes sense that there is a worldwide organization dedicated to some of these important historic places. Founded in 1993, the Organization of World Heritage Cities (OWHC) consists of 208 cities, which have a combined population of 125 million. Some of their programs include symposia and seminars dealing with the management, development, and preservation of historic sites, along with creating an active and vibrant network among these places. In the section titled âÂÂThe Preservation ChallengeâÂÂ, visitors can read some of the key documents dealing with the organization, along with information on their current initiatives. Visitors may also find out about the various cities that are part of the organization, such as Damascus, Tunis, and Galle. Finally, the site also contains registration and program material for the 8th OWHC World Symposium 2005, which will be held in Cuzco, Peru.

450

Florida Cities and Metro Areas  

NSDL National Science Digital Library

This exercise for an Urban Sociology course provides a look at demographics in Florida Metropolitan Area. This activity uses The Statistical Abstract of the United States, The County and City Data Book and The State and Metropolitan Area Data Book.

Wright, Jim

451

Residential Abandonment in Central Cities.  

National Technical Information Service (NTIS)

The abandonment of residential properties in central cities is considered in this information bulletin prepared by the Urban Coalition. The coalition is a consortium of 34 urban governments working together with Federal officials and private industry to e...

1977-01-01

452

Hawaii's Floating City Development Program.  

National Technical Information Service (NTIS)

Progress toward the engineering design, construction logistics, and the construction of large stable floating platforms is described. Plans to construct the first floating city are discussed and the planned utilization of the community described. For the ...

J. P. Craven J. A. Hanson

1972-01-01

453

75 FR 11580 - Florida Power Corporation, City of Alachua, City of Bushnell, City of Gainesville, City of...  

Federal Register 2010, 2011, 2012, 2013

...and City of Orlando, Seminole Electric Cooperative, Inc., Crystal River Unit 3 Nuclear Generating Plant; Receipt of Request...Commission (NRC) take action with regard to the licensee for the Crystal River Unit 3 Nuclear Generating Plant (CR-3). The...

2010-03-11

454

Energy in the Cities Symposium.  

National Technical Information Service (NTIS)

This report addresses city government frustration in developing conservation plans and energy management strategies caused by inadequacies of staff, finance, and interagency coordination. One paper describes the planning process of the Southern Tier Regio...

J. T. Werth

1980-01-01

455

Vision of a smart city.  

National Technical Information Service (NTIS)

The vision of 'Smart Cities' is the urban center of the future, made safe, secure environmentally green, and efficient because all structures--whether for power, water, transportation, etc. are designed, constructed, and maintained making use of advanced,...

R. E. Hall B. Bowerman J. Braverman J. Taylor H. Todosow U. Von Wimmersperg

2000-01-01

456

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.

457

Industry and the smart city  

Microsoft Academic Search

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

Zelda Bronstein

2009-01-01

458

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

PubMed Central

Histone variants are used by the cell to build specialized nucleosomes, replacing canonical histones and generating functionally specialized chromatin domains. Among many other processes, the specialization imparted by histone H2A (H2A.X and H2A.Z) variants to the nucleosome core particle constitutes the earliest response to DNA damage in the cell. Consequently, chromatin-based genotoxicity tests have been developed in those cases where enough information pertaining chromatin structure and dynamics is available (i.e., human and mouse). However, detailed chromatin knowledge is almost absent in most organisms, specially protostome animals. Molluscs (which represent sentinel organisms for the study of pollution) are not an exception to this lack of knowledge. In the present work we first identified the existence of functionally differentiated histone H2A.X and H2A.Z variants in the mussel Mytilus galloprovincialis (MgH2A.X and MgH2A.Z), a marine organism widely used in biomonitoring programs. Our results support the functional specialization of these variants based on: a) their active expression in different tissues, as revealed by the isolation of native MgH2A.X and MgH2A.Z proteins in gonad and hepatopancreas; b) the evolutionary conservation of different residues encompassing functional relevance; and c) their ability to confer specialization to nucleosomes, as revealed by nucleosome reconstitution experiments using recombinant MgH2A.X and MgH2A.Z histones. Given the seminal role of these variants in maintaining genomic integrity and regulating gene expression, their preliminary characterization opens up new potential applications for the future development of chromatin-based genotoxicity tests in pollution biomonitoring programs.

Gonzalez-Romero, Rodrigo; Rivera-Casas, Ciro; Frehlick, Lindsay J.; Mendez, Josefina; Ausio, Juan; Eirin-Lopez, Jose M.

2012-01-01

459

Study on the corrosion residual strength of the 1.0 wt.% Ce modified AZ91 magnesium alloy  

SciTech Connect

The effect of corrosion on the tensile behaviour of the 1.0 wt.% Ce modified AZ91 magnesium alloy was investigated by the immersion of the test bar in 3.5 wt.% NaCl aqueous solution for 0, 12, 40, 108, 204, 372 and 468 h with the subsequent tensile tests in this paper. The fractography was analyzed by scanning electron microscopy. The results show that pitting corrosion should be responsible for the drop of the corrosion residual strength within the testing time. The depth of the corrosion pits was statistically and quantitatively obtained by an optical microscopy and the maximal value was recorded as the extreme depth of the corrosion pit. Furthermore, the corrosion residual strength is linearly dependent on the extreme depth of the corrosion pit, which can be attributed to the loss of cross-sectional area and the emergence of stress concentration caused by the initiation and development of corrosion pits.

Li Chunfang [Key Laboratory of Automobile Materials (Jilin University), Ministry of Education, College of Materials Science and Engineering, Jilin University, Changchun 130025 (China); Liu Yaohui, E-mail: liuyaohui2005@yahoo.com [Key Laboratory of Automobile Materials (Jilin University), Ministry of Education, College of Materials Science and Engineering, Jilin University, Changchun 130025 (China); Wang Qiang; Zhang Lina; Zhang Dawei [Key Laboratory of Automobile Materials (Jilin University), Ministry of Education, College of Materials Science and Engineering, Jilin University, Changchun 130025 (China)

2010-01-15

460

Clustering Properties of 1.1 mm-Selected Submillimetre Galaxies Uncovered by AzTEC Deep Surveys  

NASA Astrophysics Data System (ADS)

We performed deep and wide-field surveys at 1.1 mm using AzTEC camera mounted on ASTE. We calculate the two-point angular autocorrelation functions in seven deep survey fields: AKARI Deep Field South (ADF-S), COSMOS, GOODS-N, GOODS-S, Lockman Hole East, SSA 22, and SXDF. We detect evidence for clustering signals in all the fields. By averaging the results on the bright sources measured in the ADF-S, the SSA 22, and the SXDF fields, we derived a more significant correlation function of 1.1 mm sources. A comparison of the correlation length with a bias evolution model of dark halos suggests that dark halos hosting bright 1.1 mm sources evolve into galaxy clusters in the present-day universe.

Hatsukade, B.; Takeuchi, T. T.; Pollo, A.; Kohno, K.; Aretxaga, I.; Austermann, J. E.; Ezawa, H.; Hughes, D. H.; Ikarashi, S.; Iono, D.; Kawabe, R.; Nakanishi, K.; Oshima, T.; Perera, T.; Scott, K. S.; Tamura, Y.; Williams, C. C.; Wilson, G. W.; Yun, M. S.

2013-10-01

461

Dissolution of Eutectic ?-Mg17Al12 Phase in Magnesium AZ91 Cast Alloy at Temperatures Close to Eutectic Temperature  

NASA Astrophysics Data System (ADS)

Knowledge on the dissolution kinetics of ?-eut phase in cast Mg AZ91 alloy at temperatures close to the eutectic temperature is very useful for various processes of the alloy. In the present study, dissolution of ?-eut phase has been investigated experimentally and considered theoretically. Results have confirmed that the kinetics of ?-eut dissolution is basically diffusion controlled. Optimum times for dissolution heat treatment practice of different sizes of cast microstructure which are cooling rate dependant during casting could be suggested based on the present calculation. For fusion welding of the alloy, the present results indicate the difficulty of having a heating rate lower than the critical value (“critical heating rate”) for a significant reduction of the phase to avoid constitutional liquation.

Zhu, Tianping; Chen, Zhan W.; Gao, Wei

2010-08-01

462

Effects of thermomechanical treatments on the microstructures and mechanical properties of GTA-welded AZ31B magnesium alloy  

NASA Astrophysics Data System (ADS)

Thermomechanical treatments were carried out to improve the properties of AZ31B joints prepared by gas tungsten arc welding. The microstructures of the joints were studied by optical microscopy and scanning electron microscopy with energy-dispersive spectrometry. Tensile tests and hardness tests were performed to investigate the effects of thermomechanical treatments on the mechanical properties of the joints. It is found that the thermomechanical-treated joints show superior mechanical properties against the as-welded joints, and their ultimate tensile strength can reach more than 92% of the base material. This mainly attributes to the formation of fine equiaxed grains in the fusion zone. After thermomechanical treatments the dendrites are transformed to fine spherical grains, and the dendritic segregation can be effectively eliminated.

Chu, Ya-jie; Chen, Jian; Li, Xiao-quan; Wu, Shen-qing; Yang, Zong-hui

2012-10-01

463

Effect of the Pulse Duty Cycle on Characteristics of Plasma Electrolytic Oxidation Coatings Formed on AZ31 Magnesium Alloy  

NASA Astrophysics Data System (ADS)

Ceramic coatings are synthesized on AZ31 magnesium alloy in alkaline silicate solution by the method of plasma electrolytic oxidation. The effect of two different duty cycles (10% and 50%) on the structure and corrosive properties of the coatings is investigated. It is found that the coatings are mainly composed of MgO, Mg2SiO4 and MgF2 through XRD analysis. SEM images indicate that coatings formed at 50% duty cycle have a relatively coarse surface with larger pore size and fewer pores, and have a slower growth rate than those formed at 10% duty cycle with the same treatment time. However, the results of potentiodynamic polarization tests demonstrate that coatings formed at 50% duty cycle exhibit better corrosion resistance as a result of more compact microstructure.

Chen, Huan; Lv, Guo-Hua; Zhang, Gu-Ling; Pang, Hua; Wang, Xing-Quan; Zhang, You-Wei; Lee, Heon-Ju; Yang, Si-Ze

2009-09-01

464

A MASSIVE MOLECULAR GAS RESERVOIR IN THE z = 5.3 SUBMILLIMETER GALAXY AzTEC-3  

SciTech Connect

We report the detection of CO J = 2{yields}1, 5{yields}4, and 6{yields}5 emission in the highest-redshift submillimeter galaxy (SMG) AzTEC-3 at z = 5.298, using the Expanded Very Large Array and the Plateau de Bure Interferometer. These observations ultimately confirm the redshift, making AzTEC-3 the most submillimeter-luminous galaxy in a massive z {approx_equal} 5.3 protocluster structure in the COSMOS field. The strength of the CO line emission reveals a large molecular gas reservoir with a mass of 5.3 x 10{sup 10}({alpha}{sub CO}/0.8) M {sub sun}, which can maintain the intense 1800 M {sub sun} yr{sup -1} starburst in this system for at least 30 Myr, increasing the stellar mass by up to a factor of six in the process. This gas mass is comparable to 'typical' z {approx} 2 SMGs and constitutes {approx_gt}80% of the baryonic mass (gas+stars) and 30%-80% of the total (dynamical) mass in this galaxy. The molecular gas reservoir has a radius of <4 kpc and likely consists of a 'diffuse', low-excitation component, containing (at least) 1/3 of the gas mass (depending on the relative conversion factor {alpha}{sub CO}), and a 'dense', high-excitation component, containing {approx}2/3 of the mass. The likely presence of a substantial diffuse component besides highly excited gas suggests different properties between the star-forming environments in z > 4 SMGs and z > 4 quasar host galaxies, which perhaps trace different evolutionary stages. The discovery of a massive, metal-enriched gas reservoir in an SMG at the heart of a large z = 5.3 protocluster considerably enhances our understanding of early massive galaxy formation, pushing back to a cosmic epoch where the universe was less than 1/12 of its present age.

Riechers, Dominik A.; Scoville, Nicholas Z. [Astronomy Department, California Institute of Technology, MC 249-17, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Capak, Peter L.; Yan, Lin [Spitzer Science Center, California Institute of Technology, MC 220-6, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Carilli, Christopher L. [National Radio Astronomy Observatory, P.O. Box O, Socorro, NM 87801 (United States); Cox, Pierre; Neri, Roberto [Institut de RadioAstronomie Millimetrique, 300 Rue de la Piscine, Domaine Universitaire, 38406 Saint Martin d'Heres (France); Schinnerer, Eva [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany); Bertoldi, Frank, E-mail: dr@caltech.ed [Argelander-Institut fuer Astronomie, Universitaet Bonn, Auf dem Huegel 71, Bonn, D-53121 (Germany)

2010-09-10

465

STAR AND DUST FORMATION ACTIVITIES IN AzTEC-3, A STARBURST GALAXY AT z = 5.3  

SciTech Connect

Analyses 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. An important observational constraint neglected in the analysis is the mass of dust giving rise to the IR emission. In this paper we add this constraint to the analysis of AzTEC-3. Adopting an upper limit to the mass of stars and a bolometric luminosity for this object, 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. We use the PEGASE population synthesis code and a chemical evolution model to follow the evolution of the galaxy's SED and its stellar and dust masses as a function of galactic age for seven different stellar initial mass functions (IMFs). We find that the model with a Top Heavy IMF provided the most plausible scenario consistent with the observational constraints. In this scenario the dust formed over a period of {approx}200 Myr, with an SFR of {approx}500 M{sub sun} yr{sup -1}. These values for the age and SFR in AzTEC-3 are significantly higher and lower, respectively, from those derived without the dust mass constraint. However, this scenario is not unique, and others cannot be completely ruled out because of the prevailing uncertainties in the age of the galaxy, its bolometric luminosity, and its stellar and dust masses. 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.

Dwek, Eli; Staguhn, Johannes G.; Arendt, Richard G.; Benford, Dominic J.; Fixsen, Dale; Maher, Stephen F.; Moseley, Samuel H.; Sharp, Elmer H. [Observational Cosmology Lab, Code 665, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Capak, Peter L. [Spitzer Science Centre, 314-6 California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125 (United States); Kovacs, Attila [University of Minnesota, 116 Church St SE, Minneapolis, MN 55414 (United States); Karim, Alexander; Schinnerer, Eva [Max-Planck-Institute fuer Astronomie, Koenigstuhl 17, D-69117, Heidelberg (Germany); Leclercq, Samuel [Institut de RadioAstronomie Millimetrique, 300 rue de la Piscine, 38406 Saint Martin d'Heres (France)

2011-09-01

466

A Massive Molecular Gas Reservoir in the z = 5.3 Submillimeter Galaxy AzTEC-3  

NASA Astrophysics Data System (ADS)

We report the detection of CO J = 2?1, 5?4, and 6?5 emission in the highest-redshift submillimeter galaxy (SMG) AzTEC-3 at z = 5.298, using the Expanded Very Large Array and the Plateau de Bure Interferometer. These observations ultimately confirm the redshift, making AzTEC-3 the most submillimeter-luminous galaxy in a massive z ~= 5.3 protocluster structure in the COSMOS field. The strength of the CO line emission reveals a large molecular gas reservoir with a mass of 5.3 × 1010(?CO/0.8) M sun, which can maintain the intense 1800 M sun yr-1 starburst in this system for at least 30 Myr, increasing the stellar mass by up to a factor of six in the process. This gas mass is comparable to "typical" z ~ 2 SMGs and constitutes gsim80% of the baryonic mass (gas+stars) and 30%-80% of the total (dynamical) mass in this galaxy. The molecular gas reservoir has a radius of <4 kpc and likely consists of a "diffuse", low-excitation component, containing (at least) 1/3 of the gas mass (depending on the relative conversion factor ?CO), and a "dense", high-excitation component, containing ~2/3 of the mass. The likely presence of a substantial diffuse component besides highly excited gas suggests different properties between the star-forming environments in z > 4 SMGs and z > 4 quasar host galaxies, which perhaps trace different evolutionary stages. The discovery of a massive, metal-enriched gas reservoir in an SMG at the heart of a large z = 5.3 protocluster considerably enhances our understanding of early massive galaxy formation, pushing back to a cosmic epoch where the universe was less than 1/12 of its present age.

Riechers, Dominik A.; Capak, Peter L.; Carilli, Christopher L.; Cox, Pierre; Neri, Roberto; Scoville, Nicholas Z.; Schinnerer, Eva; Bertoldi, Frank; Yan, Lin

2010-09-01

467

AzTEC/ASTE Deep and Wide Submillimeter Galaxy Survey in the Subaru/XMM-Newton Deep Field: Identification of VLA, Spitzer and Herschel Counterparts to 1100-?m-Selected Galaxies and Redshifts  

NASA Astrophysics Data System (ADS)

We present results of our AzTEC/ASTE submillimeter galaxies (SMGs) survey in the Subaru/XMM-Newton Deep Field (SXDF), and VLA (21 cm), Spitzer (3.6-8 ?m and 24 ?m) and Herschel (100 and 160 ?m) counterpart identifications for 1100-?m-selected SMGs. We obtained a 1100-?m map of ˜ 1200 arcmin2 with the rms noise level of ˜ 0.5 mJy (1 ?). Our AzTEC map achieved new detections of 281 sources (S/N ? 3.5 ?). For 221 of 281 AzTEC sources, we searched counterparts in order to obtain multi-wavelength data. Deep Herschel PACS 100-?m and 160-?m images cover the whole of the AzTEC map, and 34 of 221 (= 15 %) and 54 of 221 (= 24 %)AzTEC sources have PACS 100-?m and 160-?m counterparts, respectively. We found VLA radio and/or MIPS 24-?m robust (with a significance of ? 95 %) counterparts to 102 of 221 the AzTEC SMGs. In addition to this, we have developed an improved identification method using IRAC data (3.6-8 ?m) and their colors, in order to cover the AzTEC SMGs located at higher redshift such as z > 3, which is inaccessible with the existing VLA, MIPS and Herschel data alone. With this method, we have achieved another robust detections of 20 IRAC counterparts to AzTEC sources. 131 of 221 AzTEC sources have at least one robust counterparts, and 23 of 221 have more than two robust counterparts. Including tentative identifications (with a significance of ? 90 %), 171 of 221 (= 78 %) 1100-?m-selected SMGs have counterparts. We estimated photometric redshifts of the counterparts using deep near-, and med-infrared and optical data, providing zmedian of 2.2. Among them, we found that there were some 1100-?m sources faint in multi-bands data suggesting the extremely high redshift.

Ikarashi, S.; Kohno, K.; Aretxaga, I.; Arumugam, V.; Caputi, K.; Dunlop, J.; Hatsukade, B.; Hughes, D.; Iono, D.; Ivison, R.; Kawabe, R.; Motohara, K.; Nakanishi, K.; Ohta, K.; Suzuki, K.; Tamura, Y.; Umehata, H.; Wilson, G.; Yabe, K.; Yun, M.

2013-10-01

468

Sustainable Development of the Learning City  

ERIC Educational Resources Information Center

Kaunas is the second largest city in Lithuania and has strong links with its large rural hinterland. Working from the ideas and examples in "Learning Cities for a Learning Century," (Longworth, 1999) and through contact with other cities that have already implemented lifelong learning concepts, the city has, since 2001, started out on the journey…

Juceviciene, Palmira

2010-01-01

469

Infrastructure and City Competitiveness in India  

Microsoft Academic Search

Do local improvements in infrastructure provision improve city competitiveness? What public finance mechanisms stimulate local infrastructure supply? And how do local efforts compare with national decisions of placing inter-regional trunk infrastructure? In this paper, we examine how the combination of local and national infrastructure supply improve city competitiveness, measured as the city’s share of national private investment. For the empirical

Somik V. Lall; Hyoung Gun Wang; Uwe Deichmann

2010-01-01