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1

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

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

2010-07-01

2

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

... 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...

2014-07-01

3

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

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

2014-07-01

4

78 FR 32086 - 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...establishes Class E airspace at the Tuba City VHF Omni-Directional Radio Range Tactical Air Navigational Aid (VORTAC), Tuba City, AZ, to facilitate vectoring of...

2013-05-29

5

78 FR 16823 - Proposed 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...establish Class E airspace at the Tuba City VHF Omni-Directional Radio Range Tactical Air Navigational Aid (VORTAC), Tuba City, AZ to facilitate vectoring of...

2013-03-19

6

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

Federal Register 2010, 2011, 2012, 2013

...USCG-2013-0023] RIN 1625-AA00 Safety Zone; Lake Havasu Triathlon; Lake Havasu City, AZ AGENCY: Coast Guard, DHS. ACTION...temporary safety zone within the navigable waters of Lake Havasu and the London Bridge Channel for the Lake...

2013-03-20

7

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

Federal Register 2010, 2011, 2012, 2013

...RIN 1625-AA00 Safety Zone; Desert Storm Shootout; Lake Havasu, Lake Havasu...City, Arizona in support of the Desert Storm Shootout. This temporary safety...Lake Racer LLC is sponsoring the Desert Storm Shootout, which is to be...

2013-03-25

8

Food Habits and Diet Selectivity of the Brown Bullhead  

Microsoft Academic Search

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

Jeffrey L. Kline; Brian M. Wood

1996-01-01

9

Regulation of the black bullhead hepatic ?-adrenoceptors  

Microsoft Academic Search

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

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

2008-01-01

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

DNA DAMAGE AND EXTERNAL LESIONS IN BROWN BULLHEAD FROM CONTAMINATED HABITATS  

EPA Science Inventory

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

12

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

Microsoft Academic Search

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

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

2005-01-01

13

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

Microsoft Academic Search

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

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

2002-01-01

14

BLACK BULLHEAD: AN INDICATOR OF THE PRESENCE OF CHEMICAL CARCINOGENS  

EPA Science Inventory

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

15

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

Microsoft Academic Search

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

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

2009-01-01

16

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

Microsoft Academic Search

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

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

2002-01-01

17

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

USGS Publications Warehouse

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

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

2005-01-01

18

Regulation of the black bullhead hepatic beta-adrenoceptors.  

PubMed

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

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

2008-02-01

19

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

Microsoft Academic Search

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

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

1999-01-01

20

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

Microsoft Academic Search

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

Eugene C. Braig; David L. Johnson

2003-01-01

21

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, ...

22

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

23

Comparative metabolism of benzo[a]pyrene by liver microsomes of channel catfish and brown bullhead  

SciTech Connect

The authors investigated the metabolism of the carcinogen benzo[a]pyrene (BaP) by liver microsomes of channel catfish (Ictalurus punctatus) and brown bullhead (Ameiurus nebulosus) pretreated with 3-methylcholanthrene. The catfish liver microsomes metabolized BaP at a considerably lower rate than did the brown bullhead liver microsomes. Although the BaP metabolites produced by the liver microsomes of the two species were qualitatively similar, there were considerable differences in the relative proportions of individual metabolites formed. The catfish liver microsomes produced a considerably lower proportion of benzo-ring diols of BaP including BaP-7,8-diol (the proximate carcinogenic metabolite of BaP) than did the bullhead liver microsomes. Compared to the bullhead liver microsomes, the catfish microsomes converted a higher proportion of BaP to phenolic metabolites.

Yuan, Z.X.; Kumar, S.; Sikka, H.C. [State Univ. of New York Coll., Buffalo, NY (United States). Environmental Toxicology and Chemistry Lab.

1997-04-01

24

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

PubMed

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

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

2010-04-01

25

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 ...

26

Morphometry of non-native black bullhead Ameiurus melas from Slovakia  

Microsoft Academic Search

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

Andrea Novomeská; Vladimír Ková?; Stanislav Katina

2010-01-01

27

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

Microsoft Academic Search

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, Î5-androstene-17-dione, and nitrobutyl chloride, were significantly higher in brown bullheads than

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

2000-01-01

28

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

EPA Science Inventory

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

29

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

Microsoft Academic Search

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

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

2008-01-01

30

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

Microsoft Academic Search

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

Diana M. E. Otto; Thomas W. Moon

1996-01-01

31

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

32

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

SciTech Connect

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

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

1995-12-31

33

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

USGS Publications Warehouse

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

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

2008-01-01

34

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

E-print Network

Pollution-induced behavioural effects in the brown bullhead (Ameiurus nebulosus) Ross D. Breckels on biodiversity. Thus, it is important to understand the nature of pollution- induced change in aquatic ecosystems The potential effects of pollution on ecosystem health have received increased attention in recent years

Neff, Bryan D.

35

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

Microsoft Academic Search

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

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

2011-01-01

36

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

Microsoft Academic Search

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

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

2003-01-01

37

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

USGS Publications Warehouse

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

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

2011-01-01

38

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,...

39

On behavioural responses to smell and sight of alpine bullhead Cottus poecilopus Heckel for an allopatric and a sympatric population of brown trout Salmo trutta L.  

E-print Network

??Freshwater sculpins and salmonids coexist in many streams throughout the Northern hemisphere, and often constitute an important component of stream ecosystems. Alpine bullhead Cottus poecilopus… (more)

Hauge, Joakim

2007-01-01

40

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

41

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

Microsoft Academic Search

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

Ross D. Breckels; Bryan D. Neff

2010-01-01

42

Biological effects of chronic exposure to low-level radiation in bullhead catfish ({\\\\it Ameiurus natalis\\\\\\/})  

Microsoft Academic Search

Free-ranging animals that inhabit contaminated environments provide unique opportunities to evaluate the effects of contaminant exposure. In this case, yellow bullhead catfish (Ameiurus natalis) were used as biomonitors of low-level environmental radiation exposure. Biomarkers of oxidative damage, namely pronephric pigmented macrophages (PMs) and the oxidative DNA adduct 8-hydroxy-deoxyguanosine (8-OH-dG) were related to $\\\\sp{137}$Cs burdens of fish inhibiting an abandoned reactor

Clark Desmond McCreedy

1996-01-01

43

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

Microsoft Academic Search

Bioaccumulation of š³⁡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 š³⁡Cs by NaI-scintillation. Music š³⁡Cs was unrelated to sex or mass of fish, but was related

Clark D. McCreedy; L. T. Glickman; C. H. Jagoe; I. Lehr Brisbin

1997-01-01

44

Novel and optimized polymorphic microsatellite loci for brown bullhead ( Ameiurus nebulosus )  

Microsoft Academic Search

Eight novel polymorphic microsatellite markers were developed for brown bullhead (Ameiurus nebulosus). Allelic diversity varied between three and eleven alleles per locus with observed heterozygosity ranging from 0.286 to\\u000a 0.776 among 49 Detroit River fish, with no evidence of linkage disequilibrium. One locus showed deviation from Hardy-Weinberg\\u000a equilibrium likely due to null alleles. The new markers amplified in four related

L. I. SoderbergJ; J. A. Galarza; D. D. Heath

2010-01-01

45

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

Microsoft Academic Search

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

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

1999-01-01

46

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

USGS Publications Warehouse

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

Mitchell, R.T.

2000-01-01

47

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

USGS Publications Warehouse

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

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

1991-01-01

48

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

49

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

50

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

PubMed

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

Otto, D M; Moon, T W

1996-08-01

51

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

PubMed

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

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

2013-02-01

52

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

USGS Publications Warehouse

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

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

2009-01-01

53

Trace element concentrations in the dorsal muscle of white suckers and brown bullheads from two acidic Adirondack lakes  

Microsoft Academic Search

Concentrations of 14 elements (Ag, As, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Se, Sn, Tl, V, and Zn) were measured in the dorsal muscle of omnivorous white suckers and brown bullheads, fish likely to ingest sediment while feeding. The fish were collected in two acidic Adirondack lakes known to have elevated concentrations of several of these elements in their

Merrill Heit; Catherine S. Klusek

1985-01-01

54

Tumor Prevalence and Biomarkers of Exposure in Brown Bullhead ( Ameiurus nebulosus ) from Back River, Furnace Creek, and Tuckahoe River, Maryland  

Microsoft Academic Search

Brown bullheads ( Ameiurus nebulosus) were collected from 2 locations near Baltimore, Maryland, Back River and Furnace Creek, and 1 (reference) location, Tuckahoe River, to compare the prevalence of tumors (liver and skin) and visible skin lesions (fin erosion and abnormal barbels). Cytochrome P450 activity measured as ethoxyresorufin- O-deethylase, biliary PAH-like fluorescent metabolites, and fillet contaminant concentrations were determined as

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

2004-01-01

55

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

56

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

USGS Publications Warehouse

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

Zappia, Humbert

1996-01-01

57

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

Microsoft Academic Search

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

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

2011-01-01

58

Az immunregulációs zavarok vizsgálata szisztémás autoimmun kórképekben.  

E-print Network

??A primer Sjögren-szindrómával kapcsolatos vizsgálataink eredményei alapján a betegség során megnyilvánuló patológiás immunmechanizmusokban mind a természetes, mind az adaptív immunrendszer regulatórikus aktivitású elemei érintettek. A… (more)

Papp, Gábor

2012-01-01

59

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

Federal Register 2010, 2011, 2012, 2013

...Zone--Eloy, AZ Comment Period on New Evidence On May 23, 2011, an application was...is now inviting public comment on new evidence submitted by the City of Eloy on July...comment. The comment period on the new evidence is open through November 13,...

2012-10-12

60

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

Federal Register 2010, 2011, 2012, 2013

...USCG-2010-0116] RIN 1625-AA00 Safety Zone; Lake Havasu Grand Prix, Lake Havasu, AZ AGENCY: Coast Guard, DHS. ACTION: Temporary...temporary safety zone upon the navigable waters of Lake Havasu on the Colorado River in Lake Havasu City,...

2010-04-22

61

Waste Toolkit A-Z Garden waste  

E-print Network

garden waste from my department? Typically, the University Parks Department collects and recycles on the University grounds. Woody waste is handled through large shredding machines and chipped to make wood mulchWaste Toolkit A-Z Garden waste Also see `Plant Swap' in the Waste Toolkit A-Z How can I recycle

Melham, Tom

62

Waste Toolkit A-Z Garden tools  

E-print Network

Waste Toolkit A-Z Garden tools Also see `Plant Swap' in the Waste Toolkit A-Z How can I reuse projects to people in social need. Also, it's a great way to divert waste from landfill and reduce your, Thursdays & Saturdays only 11am-4pm University of Oxford Sustainability Team, September 2012 #12;

Melham, Tom

63

Patterns of {sup 137}Cs accumulation in bullhead catfish inhabiting an abandoned reactor reservoir  

SciTech Connect

The author assayed muscle {sup 137}Cs concentrations of bullhead catfish (Ameiurus natalis) in order to determine factors contributing to the bioconcentration of this fission product. Bullhead catfish (N = 173) were obtained from the Pond B reservoir, Savannah River Site, SC. Muscle {sup 137}Cs concentration did not differ between sexes (ANOVA, P = 0.631). Age of fish (1--6 yr) appeared to explain variation in {sup 137}Cs concentration (P = 0.005), but not when mass of fish was included as a model covariate (P = 0.086). Least-square means, adjusted for the covariate, suggested that 1 and 2 yr old fish (71.09 and 81.38 mean pCi/g, respectively) differed from 3, 4, 5, and 6 yr old fish (94.94, 92.34, 97.27, 90.25 mean pCi/g, respectively). Therefore, the effects of age and mass were evaluated by partitioning the data into young (1--2 yr) and older (3, 4, 5, and 6 yr) age classes. When adjusted for mass, age (young vs. old) significantly accounted for differences in {sup 137}Cs concentration (78.98 vs. 94.33 mean pCi/g; P = 0.005). Within older fish, neither age (P = 0.870) or mass (P = 0.361) significantly influenced {sup 137}Cs concentration. The effect of age within young fish was nonsignificant (P = 0.971) in contrast to the influence of mass (P = 0.044). This suggests that the contribution of `size` (mass) to {sup 137}Cs body burden is related to early growth and that these fish reach an asymptotic `steady-state` {sup 137}Cs concentration by 3 years of age.

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

1995-12-31

64

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

SciTech Connect

A synchronous fluorescent spectroscopy (SFS) method was developed to measure pyrene-type metabolites in the bile of brown bullhead (Ameiurus nebulosus) and to estimate the exposure of fish to PAHs in four Lake Erie tributaries collected in the spring and fall of 1990 and 1991. For comparison, fish biliary benzo[a]pyrene (B[a]P) metabolites were also measured by HPLC/fluorescent detection (HPLC/F). Both methods showed that concentrations of biliary PAH metabolites of fish collected in polluted rivers were significantly higher than those collected from reference rivers. Concentrations biliary metabolites of fish caught in the Black River were five to 20 times greater than those collected in Old Woman Creek by SFS and three to five times greater by HPLC/F. Fish from the Cuyahoga River had four to 24 times more biliary PAH metabolites than fish from Old Woman Creek, measured by SFS, and five to 10 times more, measured by HPLC/F. Brown bullhead from the Toussaint River had fewer PAH metabolites than fish from Old Woman Creek. Correlation analyses of the two sets of data obtained by SFS and HPLC/F showed significance by both Pearson's sample correlation and Spearman's rank correlation. This study indicates that pyrene-type metabolites determined by SFS can be used to estimate B[a]P-type metabolites in fish bile. SFS appears to be a highly sensitive method for detecting PAH metabolites and, because of its simplicity, a cost-efficient method for screening large numbers of samples for exposure to PAHs in fish.

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

1994-05-01

65

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

PubMed Central

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

Baumann, P C; Harshbarger, J C

1995-01-01

66

Phase I and II enzymes and antioxidant responses in different tissues of brown bullheads from relatively polluted and non-polluted systems.  

PubMed

Brown bullheads (Ameiurus nebulosus) were collected from the St. Lawrence River and compared in their detoxication capacities to bullheads from a relatively non-polluted aquatic system, Lac La Pęche. The content of polychlorinated biphenyls (PCBs) in white muscle was significantly higher (22-fold) in bullheads from the St. Lawrence River compared with those from Lac La Pęche. Activities of liver ethoxyresorufin O-deethylase (EROD), a common Phase I enzyme, were 2.8-fold higher in St. Lawrence River bullheads than in fish from La Pęche. Conjugation activity by hepatic glutathione S-transferase (GST) was 3-fold higher in the St. Lawrence River fish, and significantly higher activities were also detected in kidney and white muscle in these fish as compared with the Lac La Pęche group. UDP-Glucuronosyltransferase (UDPGT) activities in liver and kidney did not differ between the two groups. Activities of cytosolic superoxide dismutase (SOD) were significantly higher, while lower activities of catalase (CAT) in kidney and glutathione peroxidase (GPX) in red and white muscles were noted in the St. Lawrence River bullheads. Concentrations of total glutathione (TGSH) in the different tissues revealed significantly lower levels in liver, kidney and white muscle of bullheads from the St. Lawrence River. The changes in Phases I and II enzymes and TGSH levels in the various tissues relate to higher PCB concentrations of muscle tissue and suggest activation of detoxication capacities, but weakened antioxidant status in the bullheads from the polluted area. The results implicate the involvement of white muscle along with liver and kidney in the whole fish detoxication process. PMID:8688001

Otto, D M; Moon, T W

1996-07-01

67

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

USGS Publications Warehouse

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

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

2001-01-01

68

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

69

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

70

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

PubMed

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

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

2013-04-01

71

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

72

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

SciTech Connect

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

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

1994-12-31

73

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

NASA Astrophysics Data System (ADS)

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

Pavao-Zuckerman, M.

2011-12-01

74

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

75

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

SciTech Connect

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

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

1995-12-31

76

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

Microsoft Academic Search

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

Vasyl V. Tkach; Andrew M. Mills

2011-01-01

77

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

Microsoft Academic Search

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

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

2001-01-01

78

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

79

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

ERIC Educational Resources Information Center

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

Rostejnska, Milada; Klimova, Helena

2011-01-01

80

Waste Toolkit A-Z Mobile phones  

E-print Network

Waste Toolkit A-Z Mobile phones How to recycle your mobile phone Recycling your mobile phone makes and recycling can help to reduce the demand for new raw materials. Do not put mobile phones in the recycling waste company Most mobile phone shops recycle old mobiles, so you can either take your old mobile

Melham, Tom

81

Waste Toolkit A-Z Battery recycling  

E-print Network

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

Melham, Tom

82

Waste Toolkit A-Z Plastic Grundon  

E-print Network

, waste contractors can only recycle PETE plastic and HDPE plastic. The University's preferred waste to donate it to another department or college via the University Swap Shop (see Swap Shop in Waste ToolkitWaste Toolkit A-Z Plastic ­ Grundon Also see `Swap Shop' and `Office Recycling ­ Grundon

Melham, Tom

83

Waste Toolkit A-Z Books Oxfam  

E-print Network

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

Melham, Tom

84

Waste Toolkit A-Z Books Grundon  

E-print Network

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

Melham, Tom

85

Waste Toolkit A-Z Clothes & textiles  

E-print Network

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

Oxford, University of

86

February 2014AZ1617 What is diabetes?  

E-print Network

February 2014AZ1617 What is diabetes? Diabetes is a disease that your blood glucose, also called blood sugar, is too high. Your body needs glucose for energy to keep you going. But having too much get into the cells of your body for energy. People with diabetes don't make enough insulin or the body

Sanderson, Mike

87

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

PubMed

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

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

2011-07-01

88

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

Code of Federal Regulations, 2013 CFR

...Arizona) and Headgate Dam (Parker, Arizona) within the San Diego Captain of Port Zone. 165.1124 Section 165.1124...Arizona) and Headgate Dam (Parker, Arizona) within the San Diego Captain of Port Zone. (a) General....

2013-07-01

89

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

Code of Federal Regulations, 2012 CFR

...Arizona) and Headgate Dam (Parker, Arizona) within the San Diego Captain of Port Zone. 165.1124 Section 165.1124...Arizona) and Headgate Dam (Parker, Arizona) within the San Diego Captain of Port Zone. (a) General....

2012-07-01

90

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

Code of Federal Regulations, 2012 CFR

...Arizona) and Headgate Dam (Parker, Arizona) within the San Diego Captain of the Port Zone. 100.1102 Section 100...Arizona) and Headgate Dam (Parker, Arizona) within the San Diego Captain of the Port Zone. (a) General....

2012-07-01

91

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

Code of Federal Regulations, 2013 CFR

...Arizona) and Headgate Dam (Parker, Arizona) within the San Diego Captain of the Port Zone. 100.1102 Section 100...Arizona) and Headgate Dam (Parker, Arizona) within the San Diego Captain of the Port Zone. (a) General....

2013-07-01

92

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

USGS Publications Warehouse

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

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

2004-01-01

93

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

USGS Publications Warehouse

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

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

2009-01-01

94

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

USGS Publications Warehouse

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

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

2009-01-01

95

Cool systems for hot cities  

Microsoft Academic Search

On a hot summer day, Los Angeles, CA, like Baltimore, MD, Phoenix, AZ, Washington, D.C., and Tokyo, Japan, is c. 6-8 degrees F hotter than its surrounding areas. Dark buildings and pavement have replaced urban vegetation in these cities, absorbing more solar heat. The urban heat islands that are created result in increased air-conditioning costs, energy use, and pollution. Scientists

Hashem Akbari; Sarah Bretz

1998-01-01

96

A comparison of {beta}-adrenoceptors and muscarinic cholinergic receptors in tissues of brown bullhead catfish (Ameiurus nebulosus) from the Black River and Old Woman Creek, Ohio  

SciTech Connect

{beta}-Adrenoceptors ({beta}ARs) and muscarinic cholinergic receptors were measured in brain, gill, and heart tissues of brown bullhead catfish exposed to polycyclic aromatic hydrocarbons in the Black River, Ohio, USA, and were compared to values from Old Woman Creek, Ohio, a reference site. A decreased number of {beta}ARs were found in the gill from Black River fish, possibly indicating a compensatory response subsequent to chemical stress.

Steevens, J.A.; Baumann, P.C.; Jones, S.B. [National Biological Service, Columbia, MO (United States)

1996-09-01

97

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

Microsoft Academic Search

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

Heidi-Marie Gabler; Per-Arne Amundsen

2010-01-01

98

Mitogenic activity of fetal bovine serum, fish fry extract, insulin-like growth factor-I, and fibroblast growth factor on brown bullhead catfish cells - BB line  

Microsoft Academic Search

Biossays were performed to assess the effects of different levels of growth medium supplementation with fetal bovine serum (FBS), fish fry extract (FE), combinations of FBS and FE, and addition of insulin-like growth factor I (IGF-I) and fibroblast growth factor (FGF) on the proliferation of brown bullhead catfish cells (BB line). Treatments (n = 4) were: 2.5, 5, 10, and

J. E. P. CYRINO; D. R. MULVANEY

1999-01-01

99

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

TEMPLETON, A.M.

1999-06-02

100

Warm incremental forming of magnesium alloy AZ31  

Microsoft Academic Search

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

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

2008-01-01

101

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

102

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

PubMed

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

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

2014-09-01

103

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

104

Az egyetemi hallgatóság társadalmi arculata Magyaroszágon a két világháború között.  

E-print Network

??A két világháború közötti id?szak egyetemi hallgatóságának történetével foglalkozó munkákat idáig szinte kizárólag a politikatörténeti megközelítés uralta. A numerus clausus, illetve az 1928-as módosítás politikai… (more)

Király, Sándor

2009-01-01

105

Test Plan for Tank 241-AZ-101 Solubility Screening Tests  

SciTech Connect

Tank 241-AZ-101 (101-AZ) has been identified as one of the early tanks to be retrieved for waste pretreatment and immobilization. Retrieval of the tank waste from other tanks may require dilution. This test is to determine the effects of dilution on the mass of solids and their composition, which can be compared with tanks where dilution is required. This test plan gives test instructions, example data sheets, a waste compatibility review, and a waste stream fact sheet.

PERSON, J.C.

1999-12-03

106

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

USGS Publications Warehouse

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

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

2000-01-01

107

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

Code of Federal Regulations, 2011 CFR

...Flight Rules in the Vicinity of the Grand Canyon National Park, AZ Appendix to...Flight Rules in the Vicinity of Grand Canyon National Park, AZ Pt. 93...Flight Rules in the Vicinity of the Grand Canyon National Park, AZ...

2011-01-01

108

78 FR 25404 - Proposed Establishment of Class E Airspace; Grand Canyon, AZ  

Federal Register 2010, 2011, 2012, 2013

...Establishment of Class E Airspace; Grand Canyon, AZ AGENCY: Federal Aviation...establish Class E airspace at the Grand Canyon VHF Omni-Directional Radio Range...VOR/DME) navigation aid, Grand Canyon, AZ, to facilitate...

2013-05-01

109

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

Federal Register 2010, 2011, 2012, 2013

...Establishment of Class E Airspace; Grand Canyon, AZ AGENCY: Federal Aviation...establishes Class E airspace at the Grand Canyon VHF Omni-Directional Radio Range...VOR/DME) navigation aid, Grand Canyon, AZ, to facilitate...

2013-07-05

110

AZ-101 Mixer Pump Test Qualification Test Procedures (QTP)  

SciTech Connect

Describes the Qualification test procedure for the AZ-101 Mixer Pump Data Acquisition System (DAS). The purpose of this Qualification Test Procedure (QTP) is to confirm that the AZ-101 Mixer Pump System has been properly programmed and hardware configured correctly. This QTP will test the software setpoints for the alarms and also check the wiring configuration from the SIMcart to the HMI. An Acceptance Test Procedure (ATP), similar to this QTP will be performed to test field devices and connections from the field.

THOMAS, W.K.

2000-01-10

111

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

ERIC Educational Resources Information Center

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

Morrison Institute for Public Policy, Arizona State University, 2009

2009-01-01

112

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

113

AZ Pending Solar Right-of-Way  

E-print Network

Field Office C2 C1 FLAGSTAFF KINGMAN Kingman Field Office COLORADO LAKE PRESCOTT HAVASU CITY R D4 F1 I2 D1 G1 G1 G1 J1 K1 M3 M4 M5 K2 N1 I1 K4 H3 M1 A1 J2 L1 D3 D2 I3 H2 M2 K5 K5 SAFFORD YUMA Lake Havasu CSP Trough 24267.94 Lake Havasu FO AZA34357 Optisolar L3 Photovoltaic 6183.15 Lower Sonoran FO AZA

Laughlin, Robert B.

114

Mixer pump test plan for double shell tank AZ-101  

SciTech Connect

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

STAEHR, T.W.

1999-05-12

115

Waste Toolkit A-Z Electrical (non-hazardous)  

E-print Network

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

Melham, Tom

116

Waste Toolkit A-Z Paper confidential paper  

E-print Network

is recycled into various products including tissue paper, hand towels and photocopier paper. All typesWaste Toolkit A-Z Paper ­ confidential paper Can I recycle confidential paper? Yes. Departments and colleges can recycle confidential paper and other media (eg: CDs) through Shred-it. Shred

Melham, Tom

117

SME Annual Meeting Feb. 28-Mar. 03, 2010, Phoenix, AZ  

E-print Network

SME Annual Meeting Feb. 28-Mar. 03, 2010, Phoenix, AZ 1 Copyright Š 2010 by SME Preprint 10. Luxbacher, Virginia Tech, Blacksburg, VA M. Karmis, Virginia Tech, Blacksburg, VA ABSTRACT Growing concerns approximately 20 times greater than that of an equivalent mass of carbon dioxide. The capture of coalbed methane

118

Waste Toolkit A-Z What is Plant Swap?  

E-print Network

.admin.ox.ac.uk/estates/environment/biodiversity How do I use Plant Swap? To join Swap Shop you need to... ¡ Email kate.aydin@ admin plants, seeds, tools and other garden-related items! University areas that use Plant Swap includeWaste Toolkit A-Z Plant Swap What is Plant Swap? Plant Swap is a virtual reuse scheme

Melham, Tom

119

Department of Radiology, University of Arizona (Tucson, AZ)  

E-print Network

Department of Radiology, University of Arizona (Tucson, AZ) A Postdoctoral position is available in the lab of Dr. Russell S. Witte, PhD, in the Department of Radiology at the University of Arizona (Tucson to develop Ultrasound Current Source Density Imaging (UCSDI), a new technique that integrates cutting

Witte, Russell S.

120

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

SciTech Connect

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

BRAYTON, D.D.

2000-02-17

121

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

Federal Register 2010, 2011, 2012, 2013

...regulations during the Lake Havasu City Boat Parade of Lights on December 01, 2012...provide for the safety of the participants, crew, spectators, sponsor vessels of the regatta...1102 in support of the Lake Havasu City Boat Parade of Lights (Item 10 on Table 1...

2012-11-23

122

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

123

About some corrosion mechanisms of AZ91D magnesium alloy  

Microsoft Academic Search

The present work is dedicated to a study of the corrosion resistance of AZ91D (91% Mg) alloy in wet environments. Three industrial alloys obtained by die-casting or sand casting were subjected to salt spray corrosion tests (ASTM-B117 standard) and immersion tests. Weight loss kinetic curves were measured. Surface analysis was performed by X-ray photoelectron diffraction (XPS). After corrosion the sand

Gaia Ballerini; Ugo Bardi; Roberto Bignucolo; Giuseppe Ceraolo

2005-01-01

124

Formability study of magnesium alloy AZ31B  

NASA Astrophysics Data System (ADS)

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

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

2011-08-01

125

AZ ÖNTÖZÉS SZEREPE, JELENTĹSÉGE  

Microsoft Academic Search

Az öntözés egyik alapvető célja, hogy javítsa az egyre növekvő népesség élel-miszerrel való ellátását. A világon jelenleg a szántóterület 17%-át öntözik, vi-szont ez a felület adja az évenként betakarítható össztermés valamivel több mint 40%-át. Hazánkban a vízjogi engedéllyel rendelkező öntözésre berendezett terü-letünk 210 ezer hektár, ami a szántóterület közel 5%-a, de a ténylegesen öntözött terület évjárattól függően ennek kb. a

Lajos Helyes

2005-01-01

126

State Date Time School City AR 10/4/2010 1:00 PM eStem High Public Charter Scho Little Rock  

E-print Network

State Date Time School City AR 10/4/2010 1:00 PM eStem High Public Charter Scho Little Rock AR 10/5/2010 9:00 AM North Little Rock High School West North Little Rock AR 10/5/2010 11:00 AM Parkview Arts and Science Magnet Little Rock AZ 10/20/2010 8:00 AM San Miguel High School Tucson AZ 10/20/2010 9:30 AM BASIS

Royer, Dana

127

Effect of Ca addition on the oxidation resistance of AZ91 magnesium alloys at elevated temperatures  

Microsoft Academic Search

AZ91 magnesium alloys containing 0.27–5.22 wt.% Ca, were melted and cast to study the effects of Ca addition on oxidation\\u000a resistance at elevated temperatures. An ignition temperature test showed that the ignition of AZ91 alloy occurred at about\\u000a 350–450 °C below the melting point, whereas that of the Ca-containing AZ91 alloys did so at above 650 °C. Weight gain measurements

Byung-Ho Choi; Bong-Sun You; Won-Wook Park; Yan-Bin Huang; Ik-Min Park

2003-01-01

128

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

129

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

130

Tensile city  

E-print Network

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

Chakkour, Mario Henri

1987-01-01

131

Cool systems for hot cities  

SciTech Connect

On a hot summer day, Los Angeles, CA, like Baltimore, MD, Phoenix, AZ, Washington, D.C., and Tokyo, Japan, is c. 6-8 degrees F hotter than its surrounding areas. Dark buildings and pavement have replaced urban vegetation in these cities, absorbing more solar heat. The urban heat islands that are created result in increased air-conditioning costs, energy use, and pollution. Scientists at the Lawrence Berkeley National Laboratory have been studying the effects of roof system color and type on the energy used to cool a building. The results of this research indicate that roofing professionals should consider the reflectance (albedo) and emittance (release of absorbed heat) of the roof systems they install.

Akbari, Hashem; Bretz, Sarah

1998-09-02

132

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

133

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

134

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

SciTech Connect

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

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

2013-07-30

135

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

136

Developing superplasticity in a magnesium AZ31 alloy by ECAP  

Microsoft Academic Search

The processing of a magnesium AZ31 alloy by equal-channel angular pressing refines the grain size to ~2.2 ?m, but annealing\\u000a for 30 min at 673 K coarsens the grains to ~6.0 ?m. Despite this microstructural instability, the alloy is superplastic when\\u000a pulled in tension at temperatures in the range of 623–723 K with elongations up to >1000% at strain rates at and below 10?4 s?1. Experiments

Roberto B. Figueiredo; Terence G. Langdon

2008-01-01

137

Mixer pump test plan for double shell tank AZ-101  

SciTech Connect

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

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

1996-06-01

138

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

139

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.

140

City Mayors  

NSDL National Science Digital Library

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

141

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

Microsoft Academic Search

In the present study, the stamping process for manufacturing cell phone cases with magnesium alloy AZ31 sheets was studied using both the experimental approach and the finite element analysis. In order to determine the proper forming temperature and set up a fracture criterion, tensile tests and forming limit tests were first conducted to obtain the mechanical behaviors of AZ31 sheets

Fuh-Kuo Chen; Chih-Kun Chang

2005-01-01

142

76 FR 2000 - Modification of Class E Airspace; Show Low, AZ  

Federal Register 2010, 2011, 2012, 2013

...amend Class E airspace at Show Low, AZ, to accommodate aircraft...Instrument Approach Procedures at Show Low Regional Airport. This will...SUPPLEMENTARY INFORMATION: History On October 22, 2010, the FAA...amend controlled airspace at Show Low, AZ (75 FR 65255)....

2011-01-12

143

CONCENTRATIONS OF PESTICIDE FROM DERMAL SURFACES: A COMPARISON OF NHEXAS & AZ BORDER SAMPLES  

EPA Science Inventory

NHEXAS-AZ was a statewide survey designed to gather data on the distributions of exposure from various media. Results of intensive sampling were obtained from 179 homes. Border-AZ was a similar study focusing on homes within 40 km of the Arizona-Mexico Border; similar results...

144

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

E-print Network

Water Environment Federation. National TMDL Science and Policy Conference. Phoenix, AZ. November 13, speciation #12;Water Environment Federation. National TMDL Science and Policy Conference. Phoenix, AZ ­ 16, 2002. AVAILABILITY OF ATMOSPHERICALLY DEPOSITED MERCURY TO RUNOFF AND RECEIVING WATERS Mark C

Pitt, Robert E.

145

Determination of fracture toughness of AZ31 Mg alloy using the cohesive finite element method  

E-print Network

interest due to increasing demand for light-weight materials in industry. The AZ31 Mg alloy has attractive mechanical properties, including high specific strength, good tensile properties [1], high machinabilityDetermination of fracture toughness of AZ31 Mg alloy using the cohesive finite element method X

Chen, Long-Qing

146

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

E-print Network

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

Surface, Lauren E. (Lauren Elizabeth)

2014-01-01

147

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

148

Aging behavior of ECAP processed AZ80 Mg alloy  

NASA Astrophysics Data System (ADS)

Equal-channel angular pressing (ECAP) can produce ultrafine grain structures in metals. The processing can also dissolve second phases through mechanical alloying effects over the equilibrium solubility of alloying elements. Therefore, one can enhance mechanical properties by combining ECAP and subsequent precipitation treatment by proper aging. In this preliminary study, an AZ80 Mg alloy was investigated. The original extruded bars were subjected to ECAP at 473 K for 4 passes to achieve a significant grain refinement down to the submicrometric regime. The possibility of exploiting the aging effect to improve mechanical strength of the alloy was studied by the following two different methods. The first method consisted of ECAP processing the samples followed by aging. The second method consisted of performing a solution treatment prior to ECAP processing and then the final aging of the samples. Micro-hardness measurements and microstructure analyses showed that reprecipitation of the Mg17Al12 phase can occur during warm temperature ECAP and aging in the AZ80 alloy at grain cores in a more finely dispersed form. This precipitation behavior can potentially generate a significant contribution to the strength of the UFG alloy.

Ogushi, Yoshifumi; Mostaed, Ehsan; Dellasega, David; Vedani, Maurizio; Miyamoto, Hiroyuki; Fujiwara, Hiroshi

2014-08-01

149

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

Code of Federal Regulations, 2010 CFR

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

2010-01-01

150

City limits  

Microsoft Academic Search

City limits are to be seen not only as geographical and temporal boundaries but also as perceived and effective horizons imposed by social arrangements. Making use of both philosophical and fictional resources, Gail Weiss develops an inter?corporeal cartography of the city that explores how these horizons impinge on people's lives. Drawing on the work of Merleau?Ponty and Elizabeth Grosz, this

Gail Weiss

2005-01-01

151

Softening cities  

Microsoft Academic Search

In the U.S. we stand somewhere about the halfway point in a major shift in the way we view city building, both the process and the product that results. We have been used to seeing urbanization as a production process. (This, in itself, replaced an earlier view of the city as a necessary condition of industrial production.) More and more

R. Montgomery

1977-01-01

152

City profile  

Microsoft Academic Search

With a metropolitan population of more than 20 million and rising, Jakarta is one of the world's largest cities, the biggest city by a wide margin in Southeast Asia, and the commanding urban center of Indonesia, the world's fourth most populous country. It is also an outstanding example of an overburdened Third World metropolis struggling with problems of overpopulation and

Roman Cybriwsky; Larry R. Ford

2001-01-01

153

City Beautiful  

Microsoft Academic Search

The city beautiful movement, which in the early 20th Century advocated city beautification as a way to improve the living conditions and civic virtues of the urban dweller, had languished by the Great Depression. Today, new urban economic theory and policymakers are coming to see the provision of consumer leisure amenities as a way to attract population, especially the highly

Gerald A. Carlino; Albert Saiz

2008-01-01

154

Mexico City  

... Two small brighter patches within the hazy area indicate low fog. In the left-hand panel, the city basin appears significantly clearer, but ... very high altitudes, in contrast to the low-lying haze and fog near Mexico City. When the stereo retrieval determines that a location is ...

2013-04-18

155

8-Hydroxy-2{prime}-deoxyguanosine (8-OH-dG): A biomarker of oxidative damage in yellow bullheads chronically exposed to low-level radiation  

SciTech Connect

8-hydroxy-2{prime}-deoxyguanosine (8-OH-dG), an oxidation product of the nucleotide deoxyguanosine (dG) was used as a biomarker to assess oxidative damage in brain and gill tissues of yellow bullhead catfish (Ameiurus natalis; n = 18) inhabiting an abandoned reactor reservoir contaminated with low levels of {sup d137}Cs (Pond B, Savannah River Site, SC). DNA was isolated by chloroform-isoamyl extraction, enzymatically digested with Nuclease P1/Calf Intestinal Phosphatase, and analyzed by HPLC with electrochemical detection.Length, weight, age, condition and muscle {sup 137}Cs activity of each fish were also determined. Concentrations of 8-OH-dG were greater in brain than in gill tissues. 8-OH-dG in gill tissues decreased as condition of fish increased, but as age increased, the effect of condition declined. Brain 8-OH-dG concentration was not related to age or condition of fish, but was greater in females and the interaction between gender and {sup 137}Cs was significant. Brain 8-OH-dG was positively associated with muscle {sup 137}Cs concentration among females, but was unrelated to {sup 137}Cs concentration in males. At lower {sup 137}Cs concentrations, females tended to have fewer oxidative DNA adducts in brian than did males. Deposition of somatic lipids into eggs may provide females some anti-oxidant benefit by diminishing the contribution of lipid peroxidation to DNA damage. 8-OH-dG is a sensitive biomarker of low-level radiation exposure, however, its application in fish requires consideration of factors such as gender, age, body-condition, and the tissue type sampled.

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

1995-12-31

156

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

PubMed

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

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

2001-04-01

157

Influence of deformation on precipitation in AZ80 magnesium alloy  

NASA Astrophysics Data System (ADS)

Precipitates in the conventionally processed (solution treatment followed by aging) AZ80 alloy are coarse, cellular, and incoherent. They nucleate and grow on the basal planes of the matrix or distribute discontinuously in the alloy. Their unique morphology and undesired distribution make them ineffective for precipitation strengthening. This condition, however, can be modified by applying selected deformation and heat treatment conditions. The effect of deformation and heat treatment on the morphology and distribution of precipitates has been studied. Deformation was introduced by hot extrusion, cold rolling, or equal channel angular pressing (ECAP). The microstructures were characterized using scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The results showed that cold deformation improved precipitation more significantly than hot deformation, and twinning promoted precipitation more effectively than slip. When ECAP was applied, the Bc-route induced more precipitates than the A-route.

Yang, Ping; Wang, Li-Na; Xie, Qing-Ge; Li, Ji-Zhong; Ding, Hua; Lu, Lin-Lin

2011-06-01

158

Microstructural stability after severe plastic deformation of AZ31 Magnesium  

NASA Astrophysics Data System (ADS)

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

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

2014-08-01

159

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

160

Fabrication and characterization of AZ91/CNT magnesium matrix composites  

NASA Astrophysics Data System (ADS)

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

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

2008-12-01

161

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

162

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.

163

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

SciTech Connect

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

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

2012-06-28

164

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

SciTech Connect

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

ROMERO, S.G.

2000-01-10

165

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

166

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

167

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

168

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

Federal Register 2010, 2011, 2012, 2013

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

2012-04-04

169

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

Federal Register 2010, 2011, 2012, 2013

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

2010-08-13

170

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

Federal Register 2010, 2011, 2012, 2013

...Safety Zone; Under Water Clean Up of Copper Canyon...sponsoring the Under Water Copper Canyon Clean up, which will involve...zone; Copper Canyon Clean Up, Lake Havasu, AZ...zone will include all waters of Copper Canyon...

2010-05-11

171

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. PMID:24762937

Sonego, Paolo; Engelen, Kristof; Pertot, Ilaria

2014-01-01

172

Dr. Amar Gupta 1130 E. Helen Street # 417C, Tucson, AZ 85721  

E-print Network

1 Dr. Amar Gupta 1130 E. Helen Street # 417C, Tucson, AZ 85721 gupta@arizona.edu; (520) 626-9842 I Prize Honorable Mention. Degree awarded by M.I.T. ¡ Bachelor of Science in Electrical Engineering, 1974

Arizona, University of

173

78 FR 34558 - Modification of Class E Airspace; Clifton/Morenci, AZ  

Federal Register 2010, 2011, 2012, 2013

...AZ, to accommodate aircraft using Area Navigation (RNAV) Global Positioning System (GPS) standard instrument...necessary to accommodate IFR aircraft executing RNAV (GPS...traffic procedures and air navigation, it is certified...

2013-06-10

174

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

SciTech Connect

The proposed activity provides the description of the Data Acquisition System for Tank 241-AZ-101. This description is documented in HNF-5572, Tank 241-AZ-101 Waste Retrieval Data Acquisition System (DAS). This activity supports the planned mixer pump tests for Tank 241-AZ-101. Tank 241-AZ-101 has been selected for the first full-scale demonstration of a mixer pump system. The tank currently holds over 960,000 gallons of neutralized current acid waste, including approximately 12.7 inches of settling solids (sludge) at the bottom of the tank. As described in Addendum 4 of the FSAR (LMHC 2000a), two 300 HP mixer pumps with associated measurement and monitoring equipment have been installed in Tank 241-AZ-101. The purpose of the Tank 241-AZ-101 retrieval system Data Acquisition System (DAS) is to provide monitoring and data acquisition of key parameters in order to confirm the effectiveness of the mixer pumps utilized for suspending solids in the tank. The suspension of solids in Tank 241-AZ-101 is necessary for pretreatment of the neutralized current acid waste and eventual disposal as glass via the Hanford Waste Vitrification Plant. HNF-5572 provides a basic description of the Tank 241-AZ-101 retrieval system DAS, including the field instrumentation and application software. The DAS is provided to fulfill requirements for data collection and monitoring. This document is not an operations procedure or is it intended to describe the mixing operation. This USQ screening provides evaluation of HNF-5572 (Revision 1) including the changes as documented on ECN 654001. The changes include (1) add information on historical trending and data backup, (2) modify DAS I/O list in Appendix E to reflect actual conditions in the field, and (3) delete IP address in Appendix F per Lockheed Martin Services, Inc. request.

ROMERO, S.G.

2000-02-14

175

Improvement of microstructure and mechanical properties of AZ91\\/SiC composite by mechanical alloying  

Microsoft Academic Search

AZ91 magnesium alloy reinforced with SiC particulates was fabricated via powder metallurgy technique as well as mechanical alloying process where a planetary ball mill was employed. Microstructure and mechanical properties of the fabricated AZ91 composites had been evaluated. Microstructural study showed that grain size of the material was refined and SiC particulates were well distributed after mechanical alloying. Mechanical tests

Lü Li; M. O. Lai; M. Gupta; B. W. Chua; A. Osman

2000-01-01

176

HOSSZMETSZETI FELMÉRÉSEK ISKOLAI KONTEXTUSBAN - AZ ELS? ÁTFOGÓ MAGYAR ISKOLAI LONGITUDINÁLIS KUTATÁSI PROGRAM ELMÉLETI ÉS MÓDSZERTANI KERETEI  

Microsoft Academic Search

Az utóbbi évtizedekben megn?tt a hosszmetszeti iskolai fejl?désvizsgálatok jelent?sége. Elméleti szempontból azért fontos a longitudinális adatgy?jtés, mert a tanulók egyéni változását, a fejl?dés stabilitását vagy változékonyságát csak ezzel a technikával, a tanu- lók egymást követ? többszöri felmérésével lehet megmutatni. Az ok-okozati összefüggé- sek feltárására vállalkozó vizsgálatok során ugyancsak hosszmetszeti adatfelvétel szük- séges. A különböz? kísérletek eredményeit csak ugyanazokról a tanulókról

Szegedi Tudományegyetem

177

Electrochemical corrosion behavior of composite coatings of sealed MAO film on magnesium alloy AZ91D  

Microsoft Academic Search

Protective composite coatings were prepared on magnesium alloy AZ91D by micro-arc oxidation (MAO) treatment plus a top coating with sealing agent using multi-immersion technique under low-pressure conditions. The corrosion resistance of AZ91D alloy with composite coatings was superior evidently to that with merely MAO film. SEM observations revealed that the sealing agent was integrated with MAO film by physically interlocking;

Hongping Duan; Keqin Du; Chuanwei Yan; Fuhui Wang

2006-01-01

178

Formability of AZ31 magnesium alloy sheets at warm working conditions  

Microsoft Academic Search

Fine-grained AZ31 magnesium alloy sheets were prepared through hot-rolling process. To investigate the mechanical properties of the sheets, uniaxial tensile tests were conducted at various temperatures and strain rates. The formability of AZ31 alloy sheets at warm working conditions was evaluated by limit drawing ratio (LDR) tests and limit dome height (LDH) tests at temperatures from 50 to 240°C. It

K. F. Zhang; D. L. Yin; D. Z. Wu

2006-01-01

179

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

Microsoft Academic Search

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

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

2001-01-01

180

Low temperature superplasticity in an AZ91 magnesium alloy processed by ECAE  

Microsoft Academic Search

An AZ91 alloy with a very small grain size of about 1 ?m was processed by ECAE. The alloy showed a large elongation of 661% at a low temperature of 473 K, which is 0.5Tm. The strain rate sensitivity was about 0.3, suggesting that the low temperature superplasticity for the AZ91 alloy is related to viscous-glide of dislocations. However, the

M. Mabuchi; H. Iwasaki; K. Yanase; K. Higashi

1997-01-01

181

The relation between microstructure and corrosion behavior of GTA welded AZ31B magnesium sheet  

Microsoft Academic Search

Welding of AZ31B magnesium alloy was carried out using gas-tungsten arc (GTA) welding. The microstructure and the corrosion behavior of welded magnesium AZ31B alloy were investigated. ac and dc polarization tests were carried out on the welded Mg sheet. The microstructure was examined using optical and electron microscopy (TEM and SEM), X-ray analysis and EDS. Scanning Kelvin probe force microscopy

G. Ben-Hamu; D. Eliezer; C. E. Cross; Th. Böllinghaus

2007-01-01

182

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

NASA Astrophysics Data System (ADS)

The effect of the microstructure, particularly of ?-Mg17Al12 phase, on the formation and growth of zinc phosphate conversion coatings on magnesium alloy AZ91 (AZ91) was studied. The zinc phosphate coatings were formed on AZ91 with different microstructures produced by heat treatment. The effect of the microstructure on the zinc phosphate coatings were examined using optical microscope (OM), X-ray diffraction (XRD), coatings weight and etching weight balances, scanning electron microscopy (SEM) and salt immersion test. Results showed that as-cast AZ91 contained a high volume fraction of the ?-Mg17Al12 phase and it was dissolved into ?-Mg phase during heat treatment at 400 °C. The ?-phase became center for hydrogen evolution during phosphating reaction (cathodic sites). The decreased volume fraction of the ?-phase caused decreasing both coatings weight and etching weight of the phosphating process. However, it increased the crystal size of the coatings and improved corrosion resistance of AZ91 by immersing in 0.5 M NaCl solution. Results also showed that the structure of the zinc phosphate conversion on AZ91 consisted of two layers: an outer crystal Zn3(PO4)2ˇ4H2O (hopeite) and an inner which was mainly composed of MgZn2(PO4)2 and Mg3(PO4)2. A mechanism for the formation of two layers of the coatings was also proposed in this study.

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

2013-01-01

183

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

184

Air composition over Siberian cities.  

NASA Astrophysics Data System (ADS)

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

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

2009-04-01

185

-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

186

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

E-print Network

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

Hall, Sharon J.

187

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

188

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

PubMed

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

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

2012-07-01

189

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

PubMed

PRDM9 directs human meiotic crossover hot spots to intergenic sequence motifs, whereas budding yeast hot spots overlap regions of low nucleosome density (LND) in gene promoters. To investigate hot spots in plants, which lack PRDM9, we used coalescent analysis of genetic variation in Arabidopsis thaliana. Crossovers increased toward gene promoters and terminators, and hot spots were associated with active chromatin modifications, including H2A.Z, histone H3 Lys4 trimethylation (H3K4me3), LND and low DNA methylation. Hot spot-enriched A-rich and CTT-repeat DNA motifs occurred upstream and downstream, respectively, of transcriptional start sites. Crossovers were asymmetric around promoters and were most frequent over CTT-repeat motifs and H2A.Z nucleosomes. Pollen typing, segregation and cytogenetic analysis showed decreased numbers of crossovers in the arp6 H2A.Z deposition mutant at multiple scales. During meiosis, H2A.Z forms overlapping chromosomal foci with the DMC1 and RAD51 recombinases. As arp6 reduced the number of DMC1 or RAD51 foci, H2A.Z may promote the formation or processing of meiotic DNA double-strand breaks. We propose that gene chromatin ancestrally designates hot spots within eukaryotes and PRDM9 is a derived state within vertebrates. PMID:24056716

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

2013-11-01

190

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

PubMed

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

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

2014-11-27

191

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

Federal Register 2010, 2011, 2012, 2013

...spectators, and other vessels and users of the waterway. Background and Purpose The Lake Racer LLC is sponsoring the Desert Storm Charity Poker Run and Exhibition Run, which is to be held on Thompson Bay region of the Colorado River in Lake Havasu City,...

2010-04-14

192

City of Anaheim City Manager's Office  

E-print Network

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

de Lijser, Peter

193

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

194

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

195

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

196

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

197

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

PubMed Central

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

Martínez-Romero, Esperanza

2014-01-01

198

Coupled thermo-mechanical FE simulation of the hot splitting spinning process of magnesium alloy AZ31  

Microsoft Academic Search

Magnesium alloy AZ31 shows excellent ductility and formability at elevated temperatures, and using hot splitting spinning it can be formed into a structural component subjected to impact loadings, such as, a wheel hub of aero undercarriage or kinds of light whole wheels. In this paper, based on the analysis of microstructures and deformation characteristics of magnesium alloy AZ31, a reasonable

He Yang; Liang Huang; Mei Zhan

2010-01-01

199

1301 So. 3rd Avenue Yuma, AZ 85364 ph: 928 / 782-5113 fax: 928 / 783-0866  

E-print Network

DESCRIPTIONJOB DESCRIPTIONJOB DESCRIPTION Location: KSWT-TV Yuma, AZ Serving Yuma, AZ and El Centro, CA Job Title: ACCOUNT EXECUTIVE (Full Time) Shift: Monday to Friday-(8AM ­ 5PM) Duties: Generate new advertising revenue, develop proposals for clients to aid them in maximizing the utility of their TV dollars, breakout

Droegemeier, Kelvin K.

200

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

E-print Network

://amu.edu.az/ AZERBAIJAN Baku State University 23.09.2011 http://bsu.edu.az/en/ AZERBAIJAN University of Architecture Islamic Azad University 04.10.2010 http://www.azad.ac.ir #12;IRAN Sharif University of Technology 15://www.nationalmuseumofiran.ir/ IRAQ University of Badd 04.05.1983 http://www.univofbaghdad.com IRAQ University of Barah 30

Guidoni, Leonardo

201

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

E-print Network

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 ...

Subramanian, Vidya

202

Shared Resources Reported at NCI-Designated Cancer Centers in 2013 A-Z Listing by Cancer Center Name  

Cancer.gov

Shared Resources Reported at NCI-Designated Cancer Centers in 2013 A-Z Listing by Cancer Center Name Page 1 of 34 Cancer Center Institution Resource Name Director(s) Shared Resources Reported at NCI-Designated Cancer Centers in 2013 A-Z Listing by Cancer Center Name Alvin J.

203

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

PubMed Central

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

2010-01-01

204

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. PMID:22895070

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

2012-01-01

205

Mechanism of the formation of stannate and cerium conversion coatings on AZ91D magnesium alloys  

NASA Astrophysics Data System (ADS)

The characteristics of the formation of conversion coatings on an AZ91D Mg alloy were detailed. Because the galvanic effect prevailed around the eutectic ? + ?, alkaline stannate conversion coatings nucleated first near the ? phase where plenty Mg2+ were present. Conversely, the formation of cerium conversion coatings largely relied on an increase in the interfacial pH. Intense dissolution of the primary ? phase in acid cerium nitrate solution caused hydrogen bubble evolution, which, in turn, resulted in blisters. It is evident that the galvanic corrosion routes on the AZ91D depend on the pH of the conversion coating solution.

Lee, Y. L.; Chu, Y. R.; Chen, F. J.; Lin, C. S.

2013-07-01

206

Anticorrosive magnesium hydroxide coating on AZ31 magnesium alloy by hydrothermal method  

NASA Astrophysics Data System (ADS)

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

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

2009-09-01

207

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., Westinghouse Hanford

1996-07-16

208

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

Microsoft Academic Search

The low-power laser\\/arc hybrid welding behaviors of the AZ-based Mg alloys in similar and dissimilar joints are examined in\\u000a this study in terms of welding parameters, fusion-zone characteristics, mechanical properties, welding temperature fields,\\u000a and laser-induced arc plasma\\/plume. Experiments were conducted using a low-power (300 W) pulsed Nd:YAG laser with a gas tungsten\\u000a welding arc. The results show that the AZ-based Mg

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

2008-01-01

209

Box City Curriculum.  

ERIC Educational Resources Information Center

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

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

210

Expression of P. falciparum var genes involves exchange of the histone variant H2A.Z at the promoter.  

PubMed

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. PMID:21379342

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

2011-02-01

211

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

212

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

SciTech Connect

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

DUNCAN JB; HUBER HJ

2011-04-21

213

Construction of extrusion limit diagram for AZ31 magnesium alloy by FE simulation  

Microsoft Academic Search

The maximum speed at which magnesium can be extruded is considerably slower than that of many common aluminium extrusion alloys. This affects both the economies of production and the final mechanical behaviour. The present work quantifies the limiting extrusion speeds and ratios of magnesium alloy AZ31 as a function of billet temperature. This is done by combining hot compression test

R. Ye Lapovok; M. R Barnett; C. H. J Davies

2004-01-01

214

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

E-print Network

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

Perez, Richard R.

215

?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?. PMID:23019126

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

216

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

SciTech Connect

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

Teats, M.C.

1995-04-28

217

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

218

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

E-print Network

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

Melham, Tom

219

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

E-print Network

Waste Toolkit A-Z Envelopes How can I reduce waste envelopes? Departments and colleges can reduce waste envelopes by using internal envelopes; reusing envelopes and where appropriate, switching from in the postal service Can I recycle envelopes in the University recycling boxes? Yes, you can recycle most

Melham, Tom

220

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

221

June 2013AZ1596 Yield Monitoring technologY for irrigated  

E-print Network

June 2013AZ1596 Yield Monitoring technologY for irrigated cotton and grains in arizona: hardware of yield monitors is particularly strong in the US-Midwest where large acreage of corn and soybeans monitor use grew from 28% of corn acreage in 2001 to 44% in 2005 (Agricultural Resource Management Survey

Sanderson, Mike

222

Pneumatic Bulging of Magnesium AZ 31 Sheet Metals at Elevated Temperatures  

Microsoft Academic Search

This paper deals with forming magnesium sheet metal components like auto body parts by pneumatic bulging. Furthermore, this paper deals with the evaluation of true stress-true strain curves as well as with forming limit curves determined by pneumatic bulging at temperatures up to 350°C. It can be shown that magnesium AZ31 is quite good formable at temperatures in the range

K. Siegert; S. Jäger; M. Vulcan

2003-01-01

223

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

Microsoft Academic Search

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

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

2007-01-01

224

Study on High Strain Rate Compression Superplasticity of As-Extruded AZ31 Magnesium Alloy  

NASA Astrophysics Data System (ADS)

The grain size of as-extruded AZ31 magnesium alloy was refined by isothermal annealing pretreatment through orthogonal experiment. By using the Gleeble-3800 thermal simulator, the compression superplasticity of as-extruded AZ31 magnesium alloy was studied. The high strain rate superplastic compression was realized. The process parameters of the superplastic compression were established and the mechanism of the superplastic deformation was analyzed. The effects of deformation temperature and strain rate on the superplastic flow were investigated. The results indicated that at 250°C-300°C and strain rate at 1×10-2s-1, the true strain values were all more than 2.03. As the temperature was 300°C and the strain rate was 1×10-2s-1-1×10 s-1, the true strain values were all more than 2.18. The results showed that the as-extruded AZ31 magnesium alloy being refined presented good compression superplasticity. The main mechanism for the superplastic compressive deformation of the as-extruded AZ31 magnesium alloy was grain-boundary sliding, meanwhile, dynamic recrystallization also played a harmonious role during the superplastic deformation.

Lin, Fei; Li, Jie; Zhao, Hongwei; Sun, Lulu; Chen, Zhitong; Meng, Qingsen

2013-07-01

225

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

226

Section thickness, macrohardness and yield strength in high-pressure diecast magnesium alloy AZ91  

Microsoft Academic Search

The yield strength of high-pressure diecast (hpdc) test bars of alloy AZ91 increases with decreasing section thickness while its hardness remains approximately constant. This behaviour is in contrast with that of the gravity cast alloy, whose hardness scales with the yield strength. Vickers hardness measured on the surface of hpdc test bars using increasing loads shows that the subsurface porosity

C. H. Cáceres; W. J. Poole; A. L. Bowles; C. J. Davidson

2005-01-01

227

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

228

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

229

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

230

Hot cracking in tungsten inert gas welding of magnesium alloy AZ91D  

E-print Network

strength. Considerable researches have been carried out to study optimisation of die casting parameters,391D.13­16 Previous researches have identified porosity as a major problem in welding of AZ91D die castings.10,11 Hot cracking is also known as one of the problems in joining magnesium alloys,12

Zhou, Wei

231

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

232

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

233

Histone H2A.Z and DNA methylation are mutually antagonistic chromatin marks  

E-print Network

methylation1­6 . Methylation is associated with repression of transcriptional initiation in plants and animals of human cancer7 . In contrast to methylation, the histone variant H2A.Z is preferentially deposited biotinylated chromatin from root tissue and co-hybridized the associated DNA with control DNA on tiling

234

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. PMID:24056716

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

235

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. PMID:25059863

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

236

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

NASA Astrophysics Data System (ADS)

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

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

2014-10-01

237

Clean Cities Fact Sheet  

SciTech Connect

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

Not Available

2004-01-01

238

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

SciTech Connect

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

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

1989-09-01

239

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

240

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. PMID:23144632

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

2012-01-01

241

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

242

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

Federal Register 2010, 2011, 2012, 2013

...Temporary/Interim Manufacturing Authority; Sub-Zero, Inc.; (Refrigerators); Goodyear, AZ An application...manufacturing (T/IM) authority within FTZ 277 at the Sub-Zero, Inc. (Sub-Zero), facility, located in Goodyear, Arizona....

2011-10-11

243

76 FR 70957 - Foreign-Trade Zone 277-Western Maricopa County, AZ; Application for Manufacturing Authority, Sub...  

Federal Register 2010, 2011, 2012, 2013

...AZ; Application for Manufacturing Authority, Sub-Zero, Inc. (Refrigerators and Freezers), Goodyear...requesting manufacturing authority on behalf of Sub-Zero, Inc. (Sub-Zero), located in Goodyear, Arizona. The...

2011-11-16

244

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

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

2013-08-29

245

75 FR 2133 - Construction and Operation of the Quartzsite Solar Energy Project, La Paz County, AZ (DOE/EIS-0440)  

Federal Register 2010, 2011, 2012, 2013

...and Operation of the Quartzsite Solar Energy Project, La Paz County, AZ...EIS) for the proposed Quartzsite Solar Energy Project (Project) in La Paz County...Quartzsite, Arizona. Quartzsite Solar Energy, LLC (QSE) has applied to...

2010-01-14

246

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

Federal Register 2010, 2011, 2012, 2013

...Inspection, Packers and Stockyards Administration Designation for the Owensboro, KY; Bloomington, IL; Iowa Falls, IA; Casa Grande, AZ; Fargo, ND; Grand Forks, ND; and Plainview, TX Areas AGENCY: Grain Inspection, Packers and Stockyards...

2011-03-22

247

Influence of extrusion temperature on deformation behavior of C sf\\/AZ91D composite during semi-solid extrusion  

Microsoft Academic Search

Deformation behavior and formability of Csf\\/AZ91D magnesium composite were investigated by semi-solid extrusion between 695K and 728K, including temperatures below and above the partial melting temperature. A method of constructing kinematically admissible velocity fields for axisymmetric extrusion based on the theory of flow function was proposed. Flow lines were analyzed in Csf\\/AZ91D composite after extrusion at elevated temperatures. Based on

L. Z. Su; L. H. Qi; J. M. Zhou; H. J. Li

2011-01-01

248

Mechanism of Effects of Rare Earths on Microstructure and Properties at Elevated Temperatures of AZ91 Magnesium Alloy  

Microsoft Academic Search

By using real-space recursion method, the energetics of the undoped and A1 and\\/or RE atoms doped ?(1450) symmetric tilt grain boundaries (GBs) in AZ91 alloys were investigated. Similar calculations were performed on undoped and doped bulk ? Mg for comparison. The results showed that A1 atoms segregated at GBs in AZ91 alloys. When RE atoms were added, they also segregated

Zhang Guoying; Zhang Hui; Gao Ming; Wei Dan

2007-01-01

249

Heterogeneous nucleation and grain refinement in cast Mg(AZ91)\\/SiC p metal matrix composites  

Microsoft Academic Search

Thermal analysis and microstructural investigation have been carried out to study the heterogeneous nucleation, crystal growth and grain refinement in the solidification of magnesium alloy AZ91 and AZ91\\/SiCP composites with two different volume fractions of the reinforcement. The results show the evidence of heterogeneous nucleation of primary magnesium on SiC particles in the two composite samples, which is attributed to

A. Luo

1996-01-01

250

The deformation and fracture behavior of SiCw\\/AZ91 magnesium matrix composite during in-situ TEM straining  

Microsoft Academic Search

The deformation and fracture behavior of as-solutionized SiCw\\/AZ91 magnesium matrix composite was observed during the in-situ tensile straining in a transmission electron microscope. The results indicated that the dislocation slip was impeded by the SiC whiskers, a large number of dislocation pile-ups occurred around the whiskers. Microcracks nucleated predominately at the SiC whisker rich regions and the matrix near SiCw-AZ91

M. Y. Zheng; W. C. Zhang; K. Wu; C. K. Yao

2003-01-01

251

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

252

Flow stress and microstructure evolution of semi-continuous casting AZ70 Mg-alloy during hot compression deformation  

Microsoft Academic Search

To evaluate and predict flow stress and set up hot forging process of AZ70 magnesium alloy, hot compression tests of AZ70 magnesium alloy were carried out on Gleeble 1500D thermo-mechanics tester at 300–420 °C and strain rates of 0.001–1 s?1 with different compression degrees. It is indicated that temperature and strain rate are the main factor affecting the flow stress

Shao-kang GUAN; Li-hong WU; Li-guo WANG

2008-01-01

253

ATP-Driven Exchange of Histone H2AZ Variant Catalyzed by SWR1 Chromatin Remodeling Complex  

Microsoft Academic Search

The conserved histone variant H2AZ has an important role in the regulation of gene expression and the establishment of a buffer to the spread of silent heterochromatin. How histone variants such as H2AZ are incorporated into nucleosomes has been obscure. We have found that Swr1, a Swi2\\/Snf2-related adenosine triphosphatase, is the catalytic core of a multisubunit, histone-variant exchanger that efficiently

Gaku Mizuguchi; Xuetong Shen; Joe Landry; Wei-Hua Wu; Subhojit Sen; Carl Wu

2004-01-01

254

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

E-print Network

://amu.edu.az/ AZERBAIJAN Baku State University 23.09.2011 http://bsu.edu.az/en/ AZERBAIJAN University of Architecture Environs 16.12.2011 http://itto.org/index.asp #12;IRAN Islamic Azad University 04.10.2010 http://www.ut.ac.ir/en IRAQ University of Badd 04.05.1983 http://www.univofbaghdad.com IRAQ University of Barah 30

Guidoni, Leonardo

255

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

E-print Network

://amu.edu.az/ AZERBAIJAN Baku State University 23.09.2011 http://bsu.edu.az/en/ AZERBAIJAN University of Architecture Islamic Azad University 04.10.2010 http://www.azad.ac.ir #12;IRAN Sharif University of Technology 15.02.2004 http://www.sharif.ac.ir IRAQ University of Badd 04.05.1983 http://www.univofbaghdad.com IRAQ University

Di Pillo, Gianni

256

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

Federal Register 2010, 2011, 2012, 2013

...for the Lucas Oil Drag Boat Racing Series. This temporary...safety for the racers, crew, spectators, vessels...for The Lucas Oil Drag Boat Racing Series. This safety...of the participants, crew, spectators, sponsor...safety zone while the drag boats are on the course,...

2013-10-02

257

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

E-print Network

tradeoffs between vegetation cover, microclimate temperature, and water and energy consumption. References [1] Harlan, SL, Brazel A, Prashad L, Stevanov WL, Larsen L. (2006). Neighborhood microclimates to convert their yards from turf grasses to drought- resistant landscapes. Likely outcomes of this policy are

Hall, Sharon J.

258

An Investigation to Double Hit Deformation Behavior of AZ31 Magnesium Alloy  

SciTech Connect

In recent years magnesium alloys have been used in different industries due to their outstanding properties. The hot deformation processes are recognized to be the most applicable forming routes for these alloys. These are usually performed through multi-stage straining. Accordingly the static restoration processes may play important roles on their final microstructure and mechanical properties. In the present work double hit compression tests were applied on AZ31 magnesium alloy. The results were analyzed relying on the fractional softening relationship. The effects of strain rate and inter-pass time were discussed. Microstructural observations were addressed to describe the effects of static recrystallization on the double hit deformation behavior of AZ31 alloy.

Shamsi, M.; Hanzaki, A. Zarei; Naei, H. [School of Metallurgy and Material, university of Tehran, Tehran (Iran, Islamic Republic of)

2007-04-07

259

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

260

TIP48/Reptin and H2A.Z requirement for initiating chromatin remodeling in estrogen-activated transcription.  

PubMed

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. PMID:23637611

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

2013-04-01

261

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

PubMed Central

Background The histone variant H2A.Z has been implicated in nucleosome exchange, transcriptional activation and Polycomb repression. However, the relationships among these seemingly disparate functions remain obscure. Results We mapped H2A.Z genome-wide in mammalian ES cells and neural progenitors. H2A.Z is deposited promiscuously at promoters and enhancers, and correlates strongly with H3K4 methylation. Accordingly, H2A.Z is present at poised promoters with bivalent chromatin and at active promoters with H3K4 methylation, but is absent from stably repressed promoters that are specifically enriched for H3K27 trimethylation. We also characterized post-translational modification states of H2A.Z, including a novel species dually-modified by ubiquitination and acetylation that is enriched at bivalent chromatin. Conclusions Our findings associate H2A.Z with functionally distinct genomic elements, and suggest that post-translational modifications may reconcile its contrasting locations and roles. PMID:23034477

2012-01-01

262

Thermal analytical investigations of the magnesium alloys AM 60 and AZ 91 including the melting range  

Microsoft Academic Search

The following thermophysical properties were determined for the magnesium alloys AZ 91 and AM 60: The density in the temperature range 30–500°C, the specific heat capacity including the melting range, the melting point temperature, and the melting enthalpy. The following devices were used: NETZSCH DSC 404C Pegasus, NETZSCH DIL 402C as well as SETARAM TGDTA92 for thermogravimetric investigations within the

A. Lindemann; J. Schmidt; M. Todte; T. Zeuner

2002-01-01

263

Corrosion protection of AZ91 magnesium alloy by anodizing in niobium and zirconium-containing electrolytes  

Microsoft Academic Search

A new Nb+Zr-based anodized coating was designed for the corrosion protection of AZ91 magnesium alloy. Polarization curves and electrochemical impedance diagrams plotted in Na2SO4 electrolyte showed its high protective effect. Analysis of the chemical composition by X-ray photoelectron spectroscopy indicated that the coating mainly consisted of (i) magnesium metaborate and metaphosphate, (ii) MgF2 and ZrF4, and (iii) Nb2O5, ZrO2 and

H. Ardelean; I. Frateur; S. Zanna; A. Atrens; P. Marcus

2009-01-01

264

Low-temperature plastic deformation of AZ31 magnesium alloy with different microstructures  

Microsoft Academic Search

The plastic deformation of AZ31 magnesium alloy under tension at temperatures of 4.2-295 K is studied as a function of its microstructure following squeeze casting (SC) and after severe plastic deformation (SPD) by hot rolling and equal-channel angular pressing. SPD reduces the average grain size and creates a texture that favors basal-plane dislocation glide. It is found that plastic deformation

Yu. Z. Estrin; P. A. Zabrodin; I. S. Braude; T. V. Grigorova; N. V. Isaev; V. V. Pustovalov; V. S. Fomenko; S. E. Shumilin

2010-01-01

265

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

NASA Astrophysics Data System (ADS)

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

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

1994-05-01

266

Aging behavior of squeeze cast SiCw\\/AZ91 magnesium matrix composite  

Microsoft Academic Search

The aging behavior of SiC whisker reinforced AZ91 magnesium matrix composites was investigated with Vickers hardness measurement, differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The precipitation process observed in the monolithic alloy was not altered by the addition of SiC whiskers. The composite exhibited an accelerated hardening response compared with the unreinforced matrix alloy.

M. Y. Zheng; K. Wu; S. Kamado; Y. Kojima

2003-01-01

267

Corrosion behavior of silicon nitride bonding silicon carbide in molten magnesium and AZ91 magnesium alloy  

Microsoft Academic Search

The corrosion behaviors of silicon nitride bonding silicon carbide (Si3N4\\/SiC) composites in molten magnesium and AZ91 magnesium alloy were investigated through immersion tests. The microstructure and the component of the surface layer of the composites were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The experimental results show that there were slight corrosion phenomena

Hukui Chen; Jianrui Liu; Weidong Huang

2006-01-01

268

Producing of AZ91\\/SiC composite by friction stir processing (FSP)  

Microsoft Academic Search

Friction stir processing (FSP) was used to fabricate SiC\\/AZ91 composite layer. Effect of process parameters such as rotational\\u000a and traverse speeds, tool penetration depth and tilt angle on the formation of defects such as cracks, tunnelling cavity and\\u000a also on sticking of matrix material to the tool was investigated. Also, effect of these parameters was studied on the mechanical\\u000a properties

Parviz Asadi; Ghader Faraji; Mohammad K. Besharati

2010-01-01

269

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

270

Exceptional superplasticity in an AZ61 magnesium alloy processed by extrusion and ECAP  

Microsoft Academic Search

Experiments were conducted on a commercial AZ61 alloy to evaluate the potential for achieving an ultrafine grain size and superplastic ductilities through the use of the EX-ECAP two-step processing procedure of extrusion plus equal-channel angular pressing. The results show that EX-ECAP gives excellent grain refinement with grain sizes of ?0.6 and ?1.3?m after pressing at 473 and 523K, respectively. The

Yuichi Miyahara; Zenji Horita; Terence G. Langdon

2006-01-01

271

Cyclic deformation and fatigue behaviour of the magnesium alloy AZ91  

Microsoft Academic Search

In this report, the cyclic deformation behaviour of the die-casting magnesium alloy AZ91 was investigated at constant total strain amplitudes between 1.4×10?3 and 2×10?2 at room temperature and at 130°C. The fatigue life data at both temperatures can be described well by the laws of Manson-Coffin and Basquin. The microstructural investigations performed show the strong influence of several microstructural features

G Eisenmeier; B Holzwarth; H. W Höppel; H Mughrabi

2001-01-01

272

High current pulsed electron beam treatment of AZ31 Mg alloy  

Microsoft Academic Search

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\\/cm2 beam energy density used in the present work, the evaporation mode

Bo Gao; Shengzhi Hao; Jianxin Zou; Thierry Grosdidier; Limin Jiang; Jiyang Zhou; Chuang Dong

2005-01-01

273

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

274

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

Microsoft Academic Search

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

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

2006-01-01

275

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

Microsoft Academic Search

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

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

2010-01-01

276

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

277

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

Microsoft Academic Search

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

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

2009-01-01

278

Dynamic recrystallization and texture development during hot deformation of magnesium alloy AZ31  

Microsoft Academic Search

The dynamic recrystallization(DRX) and texture development, taking place during hot deformation of magnesium alloy AZ31 with a strong wire texture, were studied in compression at 673 K (0.73 Tm). Two kinds of samples were machined parallelly to the extruded and transverse directions of Mg alloy rods. New fine grains are evolved at original grain boundaries corrugated at low strains and

Xu-yue YANG; Ze-sheng JI; H. MIURA; T. SAKAI

2009-01-01

279

Processing maps for hot deformation of rolled AZ31 magnesium alloy plate: Anisotropy of hot workability  

Microsoft Academic Search

Processing maps on rolled AZ31 magnesium plate have been developed in the range 300–550°C and 0.0003–10s?1 by hot compression of specimens parallel to the rolling direction (RD), the transverse direction (TD), or the normal direction (ND) with a view to examine whether the hot workability is anisotropic. The processing map for RD specimens exhibited a single wide domain of workability

Y. V. R. K. Prasad; K. P. Rao

2008-01-01

280

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

281

Low temperature superplasticity of AZ91 magnesium alloy with non-equilibrium grain boundaries  

Microsoft Academic Search

The superplastic behavior of a fine-grained AZ91 alloy, processed by equal channel angular extrusion, has been investigated in a low temperature range of 423–523K. The experimental results showed a stress exponent of 2 and the activation energy for superplastic flow was in agreement with that for grain boundary diffusion of magnesium. The alloy with non-equilibrium grain boundary structures exhibited lower

M. Mabuchi; K. Ameyama; H. Iwasaki; K. Higashi

1999-01-01

282

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

Microsoft Academic Search

An AZ31 magnesium alloy tube has been deformed by the hot metal gas forming (HMGF) technique. Microstructures before and after\\u000a deformation have been investigated by using Electron Backscattered Diffraction (EBSD) and Electron Microscopy. Due to the\\u000a inhomogeneous distribution by induction heating, there is a temperature gradient distribution along the tube axis. Accordingly,\\u000a the deformation mechanism is also different. In the

Yi Liu; Xin Wu

2007-01-01

283

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

284

Fatigue crack growth behaviour of a die-cast magnesium alloy AZ91D  

Microsoft Academic Search

This paper deals with the room temperature fatigue crack growth behaviour of a die-cast magnesium alloy AZ91D. Short and long fatigue crack growth studies were done using single edge V-notched plate specimens under pulsating tension with a stress ratio of 0.1 and a frequency of 20 Hz at different maximum applied stress levels. Retardation–acceleration in growth of short cracks was

P Venkateswaran; S Ganesh Sundara Raman; S. D Pathak; Y Miyashita; Y Mutoh

2004-01-01

285

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

286

High cycle fatigue of a die cast AZ91ET4 magnesium alloy  

Microsoft Academic Search

This study reveals the micro-mechanisms of fatigue crack nucleation and growth in a commercial high-pressure die cast automotive AZ91E-T4 Mg component. Mechanical fatigue tests were conducted under R=?1 conditions on specimens machined at different locations in the casting at total strain amplitudes ranging from 0.02% to 0.5%. Fracture surfaces of specimens that failed in the high cycle fatigue regime with

M. F Horstemeyer; N Yang; Ken Gall; D. L McDowell; J Fan; P. M Gullett

2004-01-01

287

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

288

Sliding friction and wear of magnesium alloy AZ91D produced by two different methods  

Microsoft Academic Search

Alloy AZ91D is a leading magnesium alloy used for structural applications. It contains aluminum and zinc as principal alloying elements. This alloy is normally die-cast, but recent developments in semi-solid injection molding (ThixomoldingŽ), which offers certain processing advantages, produces a slightly different microstructure than die-casting, and it was of interest to determine whether the two processing routes would measurably affect

Peter J Blau; Matthew Walukas

2000-01-01

289

Chemical Speciation of PM2.5 and PM10 in South Phoenix, AZ  

Microsoft Academic Search

Phoenix, AZ, experiences high particulate matter (PM) episodes, especially in the wintertime. The spatial variation of the PM concentrations and resulting differences in exposure is of particular concern. In this study, PM2.5 (PM with aerodynamic diameter <2.5 ?m) and PM10 (PM with aerodynamic diameter <10 ?m) samples were collected simultaneously from the east and west sides of South Phoenix and

Nabin Upadhyay; Andrea Clements; Matthew Fraser; Pierre Herckes

2011-01-01

290

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

NASA Astrophysics Data System (ADS)

An external high parallel magnetic fields (MF) was imposed on the barium phosphate process of AZ91D magnesium alloy. The influences of the permanent MF on the morphology, the phase composition and the corrosion resistance of the barium phosphate coatings were studied using scanning electron microscope, X-ray diffraction, salt spay test. The results show that the coatings with MF are more compact, uniform, and smooth, and have better the corrosion resistance than without MF.

Jin, HuaLan; Yang, XiangJie; Peng, WenYi; Guo, HongMin

2010-01-01

291

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

292

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

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

1996-10-01

293

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

NASA Astrophysics Data System (ADS)

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

Sadeghi, Alireza; Martin, Étienne; Pekguleryuz, Mihriban

2014-12-01

294

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

NASA Astrophysics Data System (ADS)

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

Sadeghi, Alireza; Martin, Étienne; Pekguleryuz, Mihriban

2014-09-01

295

Flow behaviour of magnesium alloy AZ31B processed by equal-channel angular pressing  

NASA Astrophysics Data System (ADS)

Magnesium alloys are characterised by their low density, high specific strength and stiffness. But, the potential application of Mg is limited by its low room-temperature ductility & formability. Formability can be improved by developing an ultrafine grained (UFG) structure. Equal channel angular pressing (ECAP) is a well known process that can be used to develop an ultrafine grained microstructure. The aim of this study was to investigate the flow behaviour of AZ31B magnesium alloy after ECAP. The specimen was subjected to three passes of ECAP with a die angle of 120° using processing route Bc. The processing temperature was 523 K for the first pass and 423 K for the subsequent two passes. The microstructure characterisation was done. Compression tests of ECAPed and annealed specimens were carried out at strain rates of 0.01 - 1s-1 and deformation temperatures of 200 - 300°C using computer servo-controlled Gleeble-3800 system. The value of activation energy Q and the empirical materials constants of A and n were determined. The equations relating flow stress and Zener-Hollomon parameter were proposed. In the case annealed AZ31, the activation energy was determined to be 154 kJ/mol, which was slightly higher than the activation energy of 144 kJ/mol for ECAPed AZ31.

Arun, M. S.; Chakkingal, U.

2014-08-01

296

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

SciTech Connect

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

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

2005-08-05

297

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

PubMed Central

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.ZAP3) 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.ZAP3 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.ZAP3 was less tightly associated with chromatin, suggesting that the mutant is more dynamic. Notably, bivalent genes in H2A.ZAP3 ESCs displayed significant changes in expression compared to active genes. Moreover, bivalent genes in H2A.ZAP3 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.ZAP3 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.ZAP3 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

298

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

299

City Review Our 2016 Vision for City  

E-print Network

for the quality of our education, research and enterprise. City is a special place in the world of higher are proud of the quality of our education, research and enterprise and are ranked within the top 2 of Law and Saint Bartholomew's College of Nursing. Our links with the City of London are strong, through

Martin, Ralph R.

300

Smart CitieS Postdoctoral work  

E-print Network

Future oF Smart CitieS Postdoctoral work leverages predictive models P.5 enhanCing eduCation DMWA and control of dynamical flow phenomena to prevent damage to large-scale infrastructure systems, sustainable persistent monitoring of infrastructure systems using mobile autonomous platforms. Dr. Ketan Savla, Assistant

Valero-Cuevas, Francisco

301

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

RASMUSSEN, J.H.

1999-08-02

302

Detroit : open city  

E-print Network

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

Berry, Daniel (Daniel Kevin)

2006-01-01

303

Utah: Salt Lake City  

... Snow-Covered Peaks of the Wasatch and Uinta Mountains     View Larger Image ... Winter Olympics, to be held in Salt Lake City, Utah. The mountains surrounding Salt Lake City are renowned for the dry, powdery snow ...

2014-05-15

304

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

PubMed Central

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.

2014-01-01

305

City of God  

Microsoft Academic Search

Well over a millennium and a half ago, Augustine distinguished between two cities: the Heavenly City and the Earthly City. While one was the site of all that was holy and spiritual, the place of faith, the other was foul and wicked, the realm of the flesh. Such dichotomies, expanded into a full?fledged binary logic, persist in the way that

Bülent Diken

2005-01-01

306

Anthropology 310 ANCIENT CITIES  

E-print Network

Anthropology 310 ANCIENT CITIES Dr. Daphne Gallagher Office: 253 Condon Hall Email: daphne Location: 207 Chapman Course Description: Cities are common throughout the world today, with most people living in these dynamic social environments. However, cities are a relatively new phenomenon in human

307

Cities and Skills  

Microsoft Academic Search

Workers in cities earn 33% more than their nonurban counterparts. A large amount of evidence suggests that this premium is not just the result of higher ability workers living in cities, which means that cities make workers more productive. Evidence on migrants and the cross effect between urban status and experience implies that a significant fraction of the urban wage

2001-01-01

308

Cities and Homeowners Associations  

Microsoft Academic Search

In his recent article, The City as a Legal Concept, Professor Gerald Frug compared the city and the business corporation as possible vehicles for the exercise of decentralized power. In the course of his analysis, Frug asserted that American law is deeply biased against the emergence of powerful cities and, by implication, is less restrictive on corporate power. Joining the

Robert C. Ellickson

1982-01-01

309

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

310

CITY III: Small Scale.  

ERIC Educational Resources Information Center

CITY III is a computer-assisted simulation game in which participants make decisions affecting the economic, governmental, and social conditions of a simulated urban area. In one of its five city options (called Lothian) the CITY III simulation model focuses on a micro-view of an urban area by reducing the level of aggregation. The population is…

Envirometrics, Inc., Washington, DC.

311

Strategies to reduce the harmful effects of extreme heat events: a four-city study.  

PubMed

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

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

2014-02-01

312

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

PubMed Central

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

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

2014-01-01

313

Victory City: The City of the Future  

NSDL National Science Digital Library

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

314

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

315

Low-Cycle Fatigue Behavior of Die-Cast Mg Alloys AZ91 and AM60  

NASA Astrophysics Data System (ADS)

The influence of microstructure and artificial aging response (T6) on the low-cycle fatigue behavior of super vacuum die-cast (SVDC) AZ91 and AM60 has been investigated. Fatigue lifetimes were determined from the total strain-controlled fatigue tests for strain amplitudes of 0.2 pct, 0.4 pct, 0.6 pct, 0.8 pct, and 1.0 pct under fully reversed loading at a frequency of 5 Hz. Cyclic stress-strain behavior was determined using an incremental step test (IST) and compared with the more traditional constant amplitude test. Two locations in a prototype casting were investigated to examine the role of microstructure and porosity on fatigue behavior. At all total strain amplitudes microstructure refinement had a negligible impact on fatigue life because of significant levels of porosity. AM60 showed an improvement in fatigue life at higher strain amplitudes when compared with AZ91 because of higher ductility. T6 heat treatment had no impact on fatigue life. Cyclic stress-strain behavior obtained via the incremental step test varied from constant amplitude test results due to load history effects. The constant amplitude test is believed to be the more accurate test method. In general, larger initiation pores led to shorter fatigue life. The fatigue life of AZ91 was more sensitive to initiation pore size and pore location than AM60 at the lowest tested strain amplitude of 0.2 pct. Fatigue crack paths did not favor any specific phase, interdentritic structure or eutectic structure. A multistage fatigue (MSF) model showed good correlation to the experimental strain-life results. The MSF model reinforced the dominant role of inclusion (pore) size on the scatter in fatigue life.

Rettberg, Luke H.; Jordon, J. Brian; Horstemeyer, Mark F.; Jones, J. Wayne

2012-07-01

316

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

NASA Astrophysics Data System (ADS)

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

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

2014-09-01

317

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

E-print Network

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

Baradhwaj Coleppa; Felix Kling; Shufang Su

2014-04-07

318

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

SciTech Connect

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

CARLSON, A.B.

1998-11-19

319

Jegyzokonyv az MTA Matematikai Osztalya Operaciokutatasi Bizottsaga 2004. december 20i uleserol.  

E-print Network

â??allapâ??ďż˝totta, hogy a bizottsâ??ag megfelelďż˝o szâ??amban â??es Ë?osszetâ??etelben jelen van Deâ??ak Istvâ??an pâ??alyâ??azata v kapott. A kâ??erelmezďż˝o tudomâ??anyos alkalmassâ??agâ??ara a 0­1­2­3 pontos rendszerben Deâ??ak Istvâ??an a lehetsâ??eges 15 pontbâ??ol 15­Ë?ot kapott, ez 100%­nak felel meg. Indoklâ??as: Deâ??ak Istvâ??an az operâ??aciâ??okutatâ??as ter

Csendes, Tibor

320

Modeling the precipitation processes and strengthening mechanisms in a Mg-Al-(Zn) AZ91 alloy  

Microsoft Academic Search

A model is developed that couples a description of the continuous precipitation of ?-Mg17Al12 laths at elevated temperatures to a summation of the different contributions to the room-temperature 0.2 pct proof strength\\u000a in the commercial alloy AZ91 (Mg-9Al-1Zn (wt pct)). The central assumptions are the diffusion-controlled formation of shear\\u000a resistant ?-Mg17Al12 laths on the basal planes of the hcp matrix

C. R. Hutchinson; J. F. Nie; S. Gorsse

2005-01-01

321

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

Microsoft Academic Search

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

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

2005-01-01

322

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

323

Low temperature superplasticity in an AZ91 magnesium alloy processed by ECAE  

SciTech Connect

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

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

1997-03-15

324

Targeting of the SUN protein Mps3 to the inner nuclear membrane by the histone variant H2A.Z  

PubMed Central

Understanding the relationship between chromatin and proteins at the nuclear periphery, such as the conserved SUN family of inner nuclear membrane (INM) proteins, is necessary to elucidate how three-dimensional nuclear architecture is established and maintained. We found that the budding yeast SUN protein Mps3 directly binds to the histone variant H2A.Z but not other histones. Biochemical and genetic data indicate that the interaction between Mps3 and H2A.Z requires the Mps3 N-terminal acidic domain and unique sequences in the H2A.Z N terminus and histone-fold domain. Analysis of binding-defective mutants showed that the Mps3–H2A.Z interaction is not essential for any previously described role for either protein in nuclear organization, and multiple lines of evidence suggest that Mps3–H2A.Z binding occurs independently of H2A.Z incorporation into chromatin. We demonstrate that H2A.Z is required to target a soluble Mps3 fragment to the nucleus and to localize full-length Mps3 in the INM, indicating that H2A.Z has a novel chromatin-independent function in INM targeting of SUN proteins. PMID:21518795

Gardner, Jennifer M.; Smoyer, Christine J.; Stensrud, Elizabeth S.; Alexander, Richard; Gogol, Madelaine; Wiegraebe, Winfried

2011-01-01

325

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

326

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

SciTech Connect

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

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

2011-10-15

327

A Feasiblity Study on Spot Friction Welding of Magnesium Alloy AZ31  

SciTech Connect

Spot friction welding (SFW) is a novel variant of the linear friction stir welding process with the potential to create strong joints between similar, as well as dissimilar sheet metals. It is particularly suitable for soft, low melting point metals such as aluminum, magnesium, and their alloys where resistance spot welding can cause defects such as voids, trapped gas and micro-cracks due to the intense heat requirement for joint formation. Up to now, spot friction welding has focused primarily on aluminum alloys. This paper presents a feasibility study on spot friction welding of AZ31, a wrought magnesium alloy available in sheet form. Lap joints of 1.58-mm-thick magnesium alloy AZ31B-O sheet were produced by spot friction welding. The spot welds were made in 2 sec with 15-mm-diameter pin tool rotating at 500-2,000 rpm. The tool was inserted into 2-sheet stack-ups to depths of either 2.4 or 2.8 mm relative to the top sheet surface. Tensile-shear testing showed that joint strengths up to 4.75 kN were obtained. The removal of surface oxides from the sheets prior to welding increased lap shear strengths about 50% at the 2.4-mm insertion depth and it promoted failure by nugget pull-out rather than by interface separation.

Santella, Michael L [ORNL; Pan, Dr. Tsung-Yu [Ford Motor Company; Frederick, David Alan [ORNL; Schwartz, William [ORNL

2007-01-01

328

Archaeological data recovery at drill hole U19az, Nevada Test Site, Nye County, Nevada  

SciTech Connect

At the request of the Department of Energy, Nevada Field Office (DOE/NV), the Desert Research Institute (DRI) conducted archaeological data recovery at drill hole U19az on the Nevada Test Site in February 1988 and April 1990. The work focused on a site that was recommended as eligible to the National Register of Historic Places. DOE/NV chose to mitigate adverse impacts to the site though a data recovery program. The mapping and collection of artifacts took place in two discrete areas, covering almost 10 hectares (24.71 acres). In addition to surface collection, 11 test pits and 12 surface scrapes were excavated. Information was sought to address four research questions concerned with the age of the site, the subsistence and demography of the site`s inhabitants, and the behavioral implications of their lithic technology. This report describes and presents the results of the data recovery at drill hole U19az. The analyses of the artifacts indicate that the site was inhabited between 5,000 years ago and historic times. Relative artifact abundance indicates the most intense use occurred from about 4,000 to 1,500 years ago.

Lancaster, J.

1992-12-31

329

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

330

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

SciTech Connect

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

Nguyen, Ba Nghiep; Bapanapalli, Satish K.

2009-04-01

331

Mechanical Properties and Microstructure of AZ31B Magnesium Alloy Processed by I-ECAP  

NASA Astrophysics Data System (ADS)

Incremental equal channel angular pressing (I-ECAP) is a severe plastic deformation process used to refine grain size of metals, which allows processing very long billets. As described in the current article, an AZ31B magnesium alloy was processed for the first time by three different routes of I-ECAP, namely, A, BC, and C, at 523 K (250 °C). The structure of the material was homogenized and refined to ~5 microns of the average grain size, irrespective of the route used. Mechanical properties of the I-ECAPed samples in tension and compression were investigated. Strong influence of the processing route on yield and fracture behavior of the material was established. It was found that texture controls the mechanical properties of AZ31B magnesium alloy subjected to I-ECAP. SEM and OM techniques were used to obtain microstructural images of the I-ECAPed samples subjected to tension and compression. Increased ductility after I-ECAP was attributed to twinning suppression and facilitation of slip on basal plane. Shear bands were revealed in the samples processed by I-ECAP and subjected to tension. Tension-compression yield stress asymmetry in the samples tested along extrusion direction was suppressed in the material processed by routes BC and C. This effect was attributed to textural development and microstructural homogenization. Twinning activities in fine- and coarse-grained samples have also been studied.

Gzyl, Michal; Rosochowski, Andrzej; Pesci, Raphael; Olejnik, Lech; Yakushina, Evgenia; Wood, Paul

2013-11-01

332

Archaeological data recovery at drill hole U19az, Nevada Test Site, Nye County, Nevada  

SciTech Connect

At the request of the Department of Energy, Nevada Field Office (DOE/NV), the Desert Research Institute (DRI) conducted archaeological data recovery at drill hole U19az on the Nevada Test Site in February 1988 and April 1990. The work focused on a site that was recommended as eligible to the National Register of Historic Places. DOE/NV chose to mitigate adverse impacts to the site though a data recovery program. The mapping and collection of artifacts took place in two discrete areas, covering almost 10 hectares (24.71 acres). In addition to surface collection, 11 test pits and 12 surface scrapes were excavated. Information was sought to address four research questions concerned with the age of the site, the subsistence and demography of the site's inhabitants, and the behavioral implications of their lithic technology. This report describes and presents the results of the data recovery at drill hole U19az. The analyses of the artifacts indicate that the site was inhabited between 5,000 years ago and historic times. Relative artifact abundance indicates the most intense use occurred from about 4,000 to 1,500 years ago.

Lancaster, J.

1992-01-01

333

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

SciTech Connect

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

BUSSELL, J.H.

1999-08-02

334

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

SciTech Connect

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

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

2011-05-04

335

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

NASA Astrophysics Data System (ADS)

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

Tari, D. Ghaffari; Worswick, M. J.

2011-05-01

336

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

NASA Astrophysics Data System (ADS)

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

Rojaee, Ramin; Fathi, Mohammadhossein; Raeissi, Keyvan

2013-11-01

337

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

338

Microstructure Refinement After the Addition of Titanium Particles in AZ31 Magnesium Alloy Resistance Spot Welds  

NASA Astrophysics Data System (ADS)

Microstructural evolution of AZ31 magnesium alloy welds without and with the addition of titanium powders during resistance spot welding was studied using optical microscopy, scanning electron microscopy, and transmission electron microscopy (TEM). The fusion zone of AZ31 magnesium alloy welds could be divided into columnar dendritic zone (CDZ) and equiaxed dendritic zone (EDZ). The well-developed CDZ in the vicinity of the fusion boundary was clearly restricted and the coarse EDZ in the central region was efficiently refined by adding titanium powders into the molten pool, compared with the as-received alloy welds. A microstructural analysis showed that these titanium particles of approximately 8 ľm diameter acted as inoculants and promoted the nucleation of ?-Mg grains and the formation of equiaxed dendritic grains during resistance spot welding. Tensile-shear testing was applied to evaluate the effect of titanium addition on the mechanical properties of welds. It was found that both strength and ductility of magnesium alloy welds were increased after the titanium addition. A TEM examination showed the existence of an orientation matching relationship between the added Ti particles and Mg matrix, i.e., [ {0 1bar{1}0} ]_{{Mg}} // [ { 1bar{2} 1bar{3}} ]_{{Ti}} {{and}} ( {000 2} )_{{Mg}} // ( 10bar{1}0)_{{Ti}} in some grains of Ti polycrystal particles. This local crystallographic matching could promote heterogeneous nucleation of the Mg matrix during welding. The diameter of the added Ti inoculant should be larger than 1.8 ľm to make it a potent inoculant.

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

2012-02-01

339

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.

340

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

PubMed Central

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

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

2011-01-01

341

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

342

300 Cities -An Exploration in Characterizing US Cities  

E-print Network

300 Cities - An Exploration in Characterizing US Cities Michael K. Martin, Kathleen M. Carley Grouping Analyses. #12;iii Abstract The goal of the 300-Cities Project is to support IRS policy decisions by finding a small number of city clusters, where the cities within each cluster will respond similarly

Sadeh, Norman M.

343

GroWinG CitieS NJIT's Enterprise Development  

E-print Network

at thE EDgE GroWinG CitieS NJIT's Enterprise Development Center ­ the EDC ­ is home to some 90 companies at the entre- preneurial leading edge. Among them is City-Hydroponics (www. city. City-Hydroponics is advancing their agenda through the use of a multi-tier hydroponic growing system

Gary, Dale E.

344

Theme city or gated community - images of future cities  

Microsoft Academic Search

The future of the cities has been under discussion since the first city. It has been typical in every civilisation and era to hope for a better city. Creek philosopher Platon created image of future city where all men were equal and the city was ruled by philosophers minds. Many philosopher or later social scientist have ended up to similar

Leena Helenius-Mäki

2002-01-01

345

CITY of DAVIS INNOVATION CENTER  

E-print Network

03 STUDIO CITY of DAVIS INNOVATION CENTER STUDY STUDIO 30 UC Davis Extension 2012 #12;#12;03 STUDIO CITY of DAVIS INNOVATION CENTER STUDY Prepared by STUDIO 30 UC Davis Extension for the City of Davis Innovation Task Force July 2012 #12;i City of Davis Innovation Park Task Force Established by the City

California at Davis, University of

346

Procedural modeling of cities  

Microsoft Academic Search

Modeling a city poses a number of problems to computer graphics. Every urban area has a transportation network that follows population and environmental influences, and often a superimposed pattern plan. The buildings appearances follow historical, aesthetic and statutory rules. To create a virtual city, a roadmap has to be designed and a large number of buildings need to be generated.

Yoav I. H. Parish; Pascal Müller

2001-01-01

347

Growth in Cities  

Microsoft Academic Search

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

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

1992-01-01

348

Big City School Bankruptcy.  

ERIC Educational Resources Information Center

Three big-city school systems nearly went bankrupt in the 1970s. New York City, including its schools, ran out of money; Cleveland closed its schools for long periods to conserve funds; and Chicago's schools ran out of credit. This paper narrates these crises, examines the responses of state governments and teacher and custodian unions, and looks…

Cronin, Joseph M.

349

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

350

The Plains City Story  

ERIC Educational Resources Information Center

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

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

2006-01-01

351

Reproducing in Cities  

Microsoft Academic Search

Reproducing in cities has always been costly, leading to lower fertility (that is, lower birth rates) in urban than in rural areas. Historically, although cities provided job opportunities, initially residents incurred the penalty of higher infant mortality, but as mortality rates fell at the end of the 19th century, European birth rates began to plummet. Fertility decline in Africa only

Ruth Mace

2008-01-01

352

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.

353

Writing British Asian cities  

Microsoft Academic Search

This article reports in brief on an Arts and Humanities Research Council (AHRC) Diasporas, Migrations and Identities (DMI) programme funded network, ‘Writing British-Asian Cities’, which ran between 2006 and 2009. It contends that the diverse local configuration of Asian Britain has to a large extent remained unexamined in the literature. Having organised community-based events in five English cities, an indication

Seán McLoughlin

2009-01-01

354

City Signs and Lights.  

ERIC Educational Resources Information Center

Signs/Lights/Boston, a project investigating environmental information systems in urban areas, was undertaken as the first step in a process of planning and controlling signs and lights for purposes of improving the flow of information in the city. This resulting report takes the city as it is and develops explicit means for revealing its form,…

Carr, Stephen

355

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

356

Cities and Sustainable Development  

E-print Network

are paralyzed by partisan politics, city governments foster action and innovation. In the United States, helping to slash extreme poverty. Cities are also the innovation hubs for public policy. Every day, #12, Bill de Blasio, is championing a bold program of educational innovations to narrow the vast gaps

357

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

358

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

359

City of Tacoma City Manager's Office  

E-print Network

and cover letter (addressed to Nadia Chandler Hardy, Assistant to the City Manager) describing personal goals and interest in this position by August 30, 2013. Contact: Email or call Julia Smith (jbsmith of appointment. Physical Requirements and Working Conditions This position is located in an office setting

Kaminsky, Werner

360

Effects of different processing parameters on the semisolid microstructure of the AZ91D alloy during partial remelting  

Microsoft Academic Search

The effects of different processing parameters, such as heating rate, isothermal temperature and isothermal holding time, on the semisolid microstructures of the AZ91D alloy during partial remelting had been investigated in the present paper. The experimental result showed that the high heating rate shortened the growth process of renascent recrystal grains in the deformed alloys, which ultimately attributed to refine

J. G. Wang; H. Q. Lin; H. Y. Wang; Q. C. Jiang

2008-01-01

361

Warm Deep Drawing of Rectangular Parts of AZ31 Magnesium Alloy Sheet Adopting Variable Blank Holder Force  

SciTech Connect

AZ31 magnesium alloy sheet with good shape and formability is fabricated by warm cross rolling. Uniaxial tensile tests are conducted using a Gleeble 3500 thermal - mechanical simulator, and the mechanical properties of AZ31 magnesium alloy sheet are analyzed. A warm deep drawing process of square part is also simulated by the finite element method. The influences of blank holder force on the formability are numerically investigated. A double-action hydraulic press that can realize adjustable blank holder forces is developed and its working principle and control system are introduced. Some warm deep drawing experiments of square parts of AZ31 magnesium alloy sheet are also performed. Different variation schemes of the blank holder force with the stroke of the punch are tested, and the experiment results are compared. Results show that the suitable blank holder force variation scheme is a ladder curve with the punch stroke. Adopting the variable blank holder force technique can improve 13.2% of the drawing depth of square parts of AZ31 magnesium alloy sheet.

Peng Yinghong; Chang Qunfeng; Li Dayong [School of Mechanical Engineering, Shanghai Jiaotong University, 200240 (China); Zeng Xiaoqin [School of Materials Science and Engineering, Shanghai Jiaotong University, Shanghai 200240 (China)

2007-05-17

362

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 ...

363

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

E-print Network

urban density on local climate: Spatial and temporal variations in the surface energy balance energy balance in Phoenix, AZ and Portland, OR, International Journal of Climatology. Shashua-Bar, L Parameterization Scheme (LUMPS) (Grimmond & Oke 2002, Loridan et al. 2011) to model the surface energy balance

Hall, Sharon J.

364

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

365

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

Microsoft Academic Search

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

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

2005-01-01

366

1301 So. 3rd Avenue Yuma, AZ 85364 ph: 928 / 782-5113 fax: 928 / 783-0866  

E-print Network

DESCRIPTIONJOB DESCRIPTIONJOB DESCRIPTION Location: KSWT-TV El Centro, CA Serving Yuma, AZ and El Centro, CA Job advertising revenue; maintain & service existing accounts; monitor schedules placed with station to insure proper schedules, develop proposals for clients to aid them in maximizing the utility of their TV dollars

Droegemeier, Kelvin K.

367

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

E-print Network

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

Paris-Sud XI, UniversitĂŠ de

368

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

Microsoft Academic Search

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

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

2008-01-01

369

Microstructure and mechanical properties of GTA surface modified composite layer on magnesium alloy AZ31 with SiC P  

Microsoft Academic Search

A novel fabrication process of surface modified composite layer by gas tungsten arc (GTA) surface modification process was used to deposit SiC particles on the surface of magnesium alloy AZ31. This method is an effective technique in producing a high performance surface modified composite layer. The microstructure and mechanical properties of the GTA surface modified composite layer were evaluated. The

Ding Wenbin; Jiang Haiyan; Zeng Xiaoqin; Li Dehui; Yao Shoushan

2007-01-01

370

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

371

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

372

Delay Recovery from a Non-linear Polynomial-Response System R.G. van Schyndel*, A.Z. Tirkel+  

E-print Network

1 Delay Recovery from a Non-linear Polynomial-Response System R.G. van Schyndel*, A.Z. Tirkel+ , I is available for determining these model parameters [3,12]. For non-linear systems, delay measurement In this paper, we present a technique to determine a signal delay as it passes through a polynomial response non-linear

van Schyndel, Ron

373

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...

374

An investigation on microstructural and mechanical properties of solid mould investment casting of AZ91D magnesium alloy  

Microsoft Academic Search

In this work, AZ91D magnesium alloy was cast in solid plaster mould using vacuum assistance. The influence of process parameters and wall thickness on the microstructure and tensile properties of cast specimens was studied. Within the range of experimental parameters, it was found that casting and mould preheating temperatures have minor influence on mechanical properties. However, gating design proved to

S. Lun Sin; D. Dubé; R. Tremblay

2008-01-01

375

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...

376

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

EPA Science Inventory

This report documents the activities performed during and the results obtained from the first six months of the arsenic removal treatment technology demonstration project at Rimrock, AZ. The objectives of the project are to evaluate the effectiveness of AdEdge Arsenic Package Uni...

377

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

378

Microstructure, mechanical properties and texture evolution of AZ31 alloy containing trace levels of strontium  

SciTech Connect

The effect of low levels of Sr (0.01, 0.03, 0.05 wt.%) on the microstructure, mechanical properties and texture of AZ31 magnesium alloy has been investigated. Thermodynamic modeling has been used to study the effect of Sr on phase precipitation at different temperatures. Cooling curve analysis reveals a decrease in solidification superheat with the addition of 0.03 wt.% Sr to AZ31. The as-cast microstructures of the alloys have been studied using optical microscopy (OM) and electron probe micro analysis (EPMA). Results show the refining effect of Sr on the grain size and on the {beta}-Mg{sub 17}Al{sub 12} precipitates through growth poisoning and inoculation, respectively. To investigate the mechanical properties of the alloys, as-cast samples were compression tested at elevated temperatures. Hot compression peak stress ({sigma}{sub max}) and critical strain before recrystallization ({epsilon}{sub c}) initially drop but then increase. {sigma}{sub max} first decreases due to the depletion of Al from solid solution and then increases when the amount of the Al-Sr precipitates reach a significant amount. {epsilon}{sub c} drops due to the acceleration of dynamic recrystallization kinetics as a result of grain refinement. It increases with increasing Sr when the concentration Sr in solid solution is increased leading to dislocation pinning and retardation of recrystallization. X-ray texture measurements on the hot compressed and extruded samples show a decrease in maximum intensity of the basal pole figures with increasing Sr as a result of reduced twining and the changes in Al and Sr concentrations in solid solution. - Research Highlights: {yields} Microstructures/precipitates of AZ31+trace levels of Sr were examined by OM and EPMA. {yields} Thermodynamic calculations and cooling curve analysis were used to predict ppt formation. {yields} It has been shown that Sr refines the grains and Mg17Al12 precipitates. {yields} Mechanical properties and texture were studied using hot compression and X-ray diffraction. {yields} Different micro-mechanisms were responsible for mechanical and texture changes.

Sadeghi, Alireza, E-mail: alireza.sadeghi@mail.mcgill.ca; Pekguleryuz, Mihriban

2011-08-15

379

USP10 deubiquitylates the histone variant H2A.Z and both are required for androgen receptor-mediated gene activation  

PubMed Central

H2A.Z, a variant of H2A, is found at the promoters of inducible genes in both yeast and higher eukaryotes. However, its role in transcriptional regulation is complex since it has been reported to function both as a repressor and activator. We have previously found that mono-ubiquitylation of H2A.Z is linked to transcriptional silencing. Here, we provide new evidence linking H2A.Z deubiquitylation to transcription activation. We found that H2A.Z and ubiquitin-specific protease 10 (USP10) are each required for transcriptional activation of the androgen receptor (AR)-regulated PSA and KLK3 genes. USP10 directly deubiquitylates H2A.Z in vitro and in vivo, and reducing USP10 expression in prostate cancer cells results in elevated steady-state levels of mono-ubiquitylated H2A.Z (H2A.Zub1). Moreover, knockdown of USP10 ablates hormone-induced deubiquitylation of chromatin proteins at the AR-regulated genes. Finally, by sequential ChIP assays, we found that H2A.Zub1 is enriched at the PSA and KLK3 regulatory regions, and loss of H2A.Zub1 is associated with transcriptional activation of these genes. Together, these data provide novel insights into how H2A.Z ubiquitylation/deubiquitylation and USP10 function in AR-regulated gene expression. PMID:21245042

Draker, Ryan; Sarcinella, Elizabeth; Cheung, Peter

2011-01-01

380

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

381

Characterization of Al-Mn particles in AZ91D investment castings  

SciTech Connect

Manganese is currently added to Mg-Al alloys in order to improve the corrosion behavior of cast components. A part of this manganese is dissolved in the magnesium matrix and the balance is found as fine Al(Mn,Fe) particles dispersed within castings. For AZ91D specimens prepared using the plaster mould investment casting process, these particles were observed in very large quantity at the surface of castings. These particles were characterized by scanning electron microscopy and electron probe microanalysis. It was found that they consist of Al{sub 8}Mn{sub 5} phase and that their morphology and size depend on local solidification conditions. Their presence at the surface of the castings is related to low solidification rates and reduced thermal gradients at the mould/metal interface.

Lun Sin, S. [Department of Mining, Metallurgical and Materials Engineering, Laval University, Quebec, Quebec, G1K 7P4 (Canada); Dube, D. [Department of Mining, Metallurgical and Materials Engineering, Laval University, Quebec, Quebec, G1K 7P4 (Canada)], E-mail: dominique.dube@gmn.ulaval.ca; Tremblay, R. [Department of Mining, Metallurgical and Materials Engineering, Laval University, Quebec, Quebec, G1K 7P4 (Canada)

2007-10-15

382

An Experimental Study on the Stability of Superplastic Deformation of AZ31 Mg Alloy  

SciTech Connect

Optimum variable strain rate forming paths based on two different multiscale deformation-based stability criteria were developed. These criteria account for both geometrical necking (macroscopic feature) and microstructural evolution. In the first criterion, we defined the onset of instability using Hart's stability analysis, where a linear perturbation in a small region along the tensile specimen is introduced. In the second criterion, we introduced a modified one dimensional nonlinear long wavelength analysis, based on the one introduced by Hutchinson and Neale. The two stability criteria are calibrated for the AZ31 magnesium alloy at 400 deg. C, yielding two different variable strain rate forming paths. Uniaxial tensile tests are carried out following the derived forming paths to examine the validity of both criteria. Results show that the linear approach underestimates the amount of uniform deformation, and therefore prolongs the forming time to prevent failure compared to the nonlinear analysis.

Abu-Farha, F. K.; Nazzal, M. A.; Khraisheh, M. K. [Center for Manufacturing, University of Kentucky, Lexington, KY 40506 (United States); Mechanical Engineering Department, University of Kentucky, Lexington, KY 40506 (United States)

2007-04-07

383

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

384

Evaluation of cracking in the 241-AZ tank farm ventilation line at the Hanford Site  

SciTech Connect

In the period from April to October of 1988, a series of welding operations on the outside of the AZ Tank Farm ventilation line piping at the Hanford Site produced unexpected and repeated cracking of the austenitic stainless steel base metal and of a seam weld in the pipe. The ventilation line is fabricated from type 304L stainless steel pipe of 24 inch diameter and 0.25 inch wall thickness. The pipe was wrapped in polyethylene bubble wrap and buried approximately 12 feet below grade. Except for the time period between 1980 and 1987, impressed current cathodic protection has been applied to the pipe since its installation in 1974. The paper describes the history of the cracking of the pipe, the probable cracking mechanisms, and the recommended future action for repair/replacement of the pipe.

ANANTATMULA, R.P.

1999-10-20

385

Simulation of cylindrical cup drawing of AZ31 sheet metal with crystal plasticity finite element method  

NASA Astrophysics Data System (ADS)

As a light-weight structural material, magnesium alloys show good potential in improving the fuel efficiency of vehicles and reducing CO2 emissions. However, it is well known that polycrystalline Mg alloys develop pronounced crystallographic texture and plastic anisotropy during rolling, which leads to earing phenomenon during deep drawing of the rolled sheets. It is vital to predict this phenomenon accurately for application of magnesium sheet metals. In the present study, a crystal plasticity model for AZ31 magnesium alloy that incorporates both slip and twinning is established. Then the crystal plasticity model is implemented in the commercial finite element software ABAQUS/Explicit through secondary development interface (VUMAT). Finally, the stamping process of a cylindrical cup is simulated using the developed crystal plasticity finite element model, and the predicting method is verified by comparing with experimental results from both earing profile and deformation texture.

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

2013-12-01

386

Warm Deep Drawing Of Rectangular Cups With Magnesium Alloy AZ31 Sheets  

SciTech Connect

Recently, magnesium alloys have been widely applied in automotive and electronic industries as the lightest weight structural and functional materials. Warm forming of magnesium alloys has attracted much attention due to the very poor formability of Mg alloys at room temperature. The formability of magnesium alloy sheet at elevated temperature is significantly affected by the processing parameters. Among them the forming temperature, the punch speed, the geometrical shape of the blank, the blank holder force and the lubrication are probably the most relevant. In this research, the deep drawing of rectangular cups with AZ31 sheets was conducted at elevated temperatures with different process parameters. The finite element analyses were performed to investigate the effects of the process parameters on the formability of rectangular cup drawing and to predict the process defects during the process. The material yield condition was modeled using the isotropic Von Mises criterion. The flow stress data were obtained from tensile tests.

Ren, L. M. [Department of Mechanical and Management Engineering (DIMeG), Polytechnic of Bari, 70126 Bari (Italy); Institute of Metal Research, Chinese Academy of Sciences, 110016 Shenyang (China); Palumbo, G.; Tricarico, L. [Department of Mechanical and Management Engineering (DIMeG), Polytechnic of Bari, 70126 Bari (Italy); Zhang, S. H. [Institute of Metal Research, Chinese Academy of Sciences, 110016 Shenyang (China)

2007-05-17

387

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

388

Microstructural Aspects of Damage and Fracture in AZ31 Sheet Materials  

NASA Astrophysics Data System (ADS)

There are considerable data in the literature dealing with deformation mechanisms in AZ31 sheets. However, there is little information on the damage and fracture processes in this material. In this contribution, digital image correlation is used to follow deformation patterns occurring during tensile and v-bending tests at room temperature. A variety of surface analysis techniques and three-dimensional x-ray tomography have been used to examine the relationship between deformation, damage initiation, and the final fracture processes. The results show that premature diffuse necking occurs in the tensile tests without transit into localized necking. Deformation twins cluster by an autocatalytic process to form shear bands serving as preferential sites for strain localization and crack initiation. Damage appears in the form of microcracks within the shear bands at a late stage of necking and lead to the final fracture. The presence and the distribution of second-phase particles and their distributions help accelerate the final fracture processes.

Kang, Jidong; Wilkinson, David S.; Mishra, Raja K.; Embury, J. David; Essadiqi, Elhachmi; Javaid, Amjad

2013-05-01

389

Initiation of fatigue cracks in AZ91 Mg alloy processed by ECAP  

NASA Astrophysics Data System (ADS)

Mechanism of fatigue crack initiation was investigated in ultrafine-grained (UFG) magnesium alloy AZ91 processed by equal channel angular pressing (ECAP). Fatigue behaviour of UFG material was compared to the behaviour of material in an initial as-cast state. Focused ion beam technique (FIB) was applied to reveal the surface relief and early fatigue cracks. Two substantially different mechanisms of crack initiation were observed in UFG structure, which can be characterized as bimodal even after 6 ECAP passes by route Bc. The bimodality consists in a coexistence of very fine grained areas with higher content of Mg17Al12 particles and areas exhibiting somewhat larger grains and lower density of particles. The fatigue cracks which initiate in areas of larger grains are related to the cyclic slip bands; this initiation mechanism is similar to that observed in cast alloy. The second initiation mechanism is related to the grain boundary cracking which takes place predominantly in the fine grained areas.

Fintová, S.; Kunz, L.

2014-08-01

390

Grain Refinement of AZ31 Magnesium Alloy Weldments by AC Pulsing Technique  

NASA Astrophysics Data System (ADS)

The current study has investigated the influence of alternating current pulsing on the structure and mechanical properties of AZ31 magnesium alloy gas tungsten arc (GTA) weldments. Autogenous full penetration bead-on-plate GTA welds were made under a variety of conditions including variable polarity (VP), variable polarity mixed (VPM), alternating current (AC), and alternating current pulsing (ACPC). AC pulsing resulted in significant refinement of weld metal when compared with the unpulsed conditions. AC pulsing leads to relatively finer and more equiaxed grain structure in GTA welds. In contrast, VP, VPM, and AC welding resulted in predominantly columnar grain structures. The reason for this grain refinement may be attributed to the periodic variations in temperature gradient and solidification rate associated with pulsing as well as weld pool oscillation observed in the ACPC welds. The observed grain refinement was shown to result in an appreciable increase in fusion zone hardness, tensile strength, and ductility.

Kishore Babu, N.; Cross, C. E.

2012-11-01

391

Formation Mechanism of Discoloration on Die-Cast AZ91D Components Surface After Chemical Conversion  

NASA Astrophysics Data System (ADS)

A notebook (NB) computer component was manufactured from AZ91D Mg alloy by a die-casting process. After chemical conversion treatment, a discoloration was noted on the component surface. The source of this discoloration has been studied in detail by scanning electron microscopy, energy dispersive spectroscopy, and spark atomic absorption spectroscopy. The corrosion resistance was also measured by potentiodynamic polarization, hydrogen evolution and salt spray testing. The formation mechanism for the discoloration which was caused by the residue left behind by excess mold release agent sprayed during the die-casting was discussed in detail. After chemical conversion treatment, the residual-baked mold release agent was apparent on the component surface as "white ash." Consequently, it degraded seriously both the appearance and the corrosion resistance of the manufactured component.

Liu, Bao-sheng; Wei, Ying-hui; Hou, Li-feng

2013-01-01

392

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

SciTech Connect

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

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

2007-03-15

393

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

NASA Astrophysics Data System (ADS)

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

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

2012-11-01

394

Investigation of interfacial interaction between uncoated and coated carbon fibres and the magnesium alloy AZ91.  

PubMed

Unidirectionally reinforced metal-matrix composites with a fibre volume content between 63 and 68% were processed by squeeze casting using T800 H carbon fibres and the magnesium alloy AZ91. The surface of the fibres was prepared by thermal desizing of the fibres or by deposition of a pyrolytic carbon (pyC) coating. Different interfacial conditions could be identified by transmission electron microscopy (TEM) and the single-fibre push-in test. TEM confirmed the formation of needle-like phases at the fibre surface or, for coated fibres, within the pyrolytic carbon coating. During loading by the Vickers type indenter an intense response was observed for composites of coated fibres and the magnesium alloy. This could by caused by stick-slip effects within the pyrolytic carbon coating. PMID:12397483

Dorner-Reisel, A; Nishida, Y; Klemm, V; Nestler, K; Marx, G; Müller, E

2002-10-01

395

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

396

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

397

Archaeological studies at Drill Hole U20az Pahute Mesa, Nye county, Nevada. [Contains bibliography  

SciTech Connect

During the summer of 1987, the Quaternary Sciences Center (formerly Social Science Center) of the Desert Research Institute (DRI), University of Nevada System, conducted data recovery investigations at five archaeological sites located near Drill Hole U20az on the Nevada Test Site in southern Nevada. These sites were among 12 recorded earlier during an archaeological survey of the drill hole conducted as part of the environmental compliance activities of the Department of Energy (DOE). The five sites discussed in this report were considered eligible for the National Register of Historic Places and were in danger of being adversely impacted by construction activities or by effects of the proposed underground nuclear test. Avoidance of these sites was not a feasible alternative; thus DRI undertook a data recovery program to mitigate expected adverse impacts. DRI's research plan included controlled surface collections and excavation of the five sites in question, and had the concurrence of the Nevada Division of Historic Preservation and Archaeology and the Advisory Council of Historic Preservation. Of the five sites investigated, the largest and most complex, 26Ny5207, consists of at least three discrete artifact concentrations. Sites 26Ny5211 and 26Ny5215, both yielded considerable assemblages. Site 26Ny5206 is very small and probably is linked to 26Ny5207. Site 26Ny5205 contained a limited artifact assemblage. All of the sites were open-air occurrences, and, with one exception contained no or limited subsurface cultural deposits. Only two radiocarbon dates were obtained, both from 26Ny5207 and both relatively recent. While the investigations reported in the volume mitigate most of the adverse impacts from DOE activities at Drill Hole U20az, significant archaeological sites may still exist in the general vicinity. Should the DOE conduct further activities in the region, additional cultural resource investigations may be required. 132 refs., 71 figs., 44 tabs.

Simmons, A.H.; Hemphill, M.L.; Henton, G.H.; Lockett, C.L.; Nials, F.L.; Pippin, L.C.; Walsh, L.

1991-07-01

398

Transforming Cities With Transit  

NSDL National Science Digital Library

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

Cervero, Robert.; Iuchi, Kanako; Suzuki, Hiroaki

399

City sewer collectors biocorrosion  

NASA Astrophysics Data System (ADS)

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

Ksia¸?ek, Mariusz

2014-12-01

400

Light in the city  

E-print Network

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

Srinivasan, Kavita, 1976-

2002-01-01

401

Between house and city  

E-print Network

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

Kallus, Rachel Admati

1982-01-01

402

Sister Cities International  

NSDL National Science Digital Library

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

403

The 3Cities Project  

NSDL National Science Digital Library

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

1997-01-01

404

The sustainable city  

SciTech Connect

Natural marshes are replacing expensive man-made sewage treatment plants. Leaves that once wound up in landfills are now enhancing soils. Ecological landscaping is cooling entire communities and reducing energy use. In coming to view our cities as ecosystems, we are learning to apply the concepts and principles that have sustained rural forests and farms for generations. The question now is, how can those concepts be applied to cities, and how can individual citizens - as well as community leaders - act to improve the sustainability of the places they call home. This article discusses the following topics in reference to developing cities which can sustain themselves: energy efficiency; pollution and waste reduction; capturing natural processes (taking advantage of species that thrive in and benefit the city); merging ecological, economic, and social factors. 6 figs.

Gangloff, D.

1995-05-01

405

Adrift in the City  

Microsoft Academic Search

The life style of homeless children in two South American cities is reported in this chapter. The chapter describes a society within a society complete with mores, sanctions and values. The author's use of the term \\

Mark Connolly

1990-01-01

406

The Sustainable City.  

ERIC Educational Resources Information Center

Focuses on methods to make cities more sustainable through the processes of energy efficiency, pollution and waste reduction, capture of natural processes, and the merger of ecological, economic, and social factors. (LZ)

Gangloff, Deborah

1995-01-01

407

Development of a comprehensive city assessment tool: CASBEE-City  

Microsoft Academic Search

Conducting city assessments and disclosing those results to the public is important for supporting citizens' understanding of the actual condition of their city. Such assessment and disclosure could introduce a market mechanism that can be expected to provide city governments with strong incentives to improve their city conditions and also recognizes that local policy and strategy can be the most

Shuzo Murakami; Shun Kawakubo; Yasushi Asami; Toshiharu Ikaga; Nobuhaya Yamaguchi; Shinichi Kaburagi

2011-01-01

408

City of Palo Alto (ID # 4168) City Council Staff Report  

E-print Network

: Recommendation that the City Council Adopt a Resolution Amending the City's Renewable Energy Resources (Attachment A) amending the City of Palo Alto Electric Utility's Renewable Energy Resources Procurement Plan renewable energy resources by 2015. The City's goal exceeds California's Renewable Portfolio Standard (RPS

409

Switching cities off  

Microsoft Academic Search

In this follow?up to a piece originally published in City 8(2), Stephen Graham offers a detailed portrait of the tactics and techniques of contemporary urban warfare. As cities have become more reliant than ever on networks, and as their infrastructures have become more fragile due to the vagaries of neoliberal privatization, urban?based warfare, which targets the systems—informational, medical, agricultural, and

Stephen Graham

2005-01-01

410

The Cities Alliance  

NSDL National Science Digital Library

Sponsored by the World Bank and other organizations, the Cities Alliance is "a global coalition of cities and their development partners committed to scaling up successful approaches to poverty reduction." The "News" area is front and center on their homepage and it provides a fine overview of their work, which ranges from concerted efforts to upgrade slums in the developing world, developing strategies to help cities with their financial situation, and also working on cohesive and comprehensive development strategies. Visitors can click on the right-hand side of the page to learn more about each of these thematic areas in the "Cities Alliance Activities" section. Moving on, the "Publications" area with its annual reports, fact sheets, and archived e-newsletters is a place worth visiting as well. The site is rounded out by the "City Development Strategies" area, which offers a rigorous explanation of the ways in which cities can assess their existing strengths and what the key aspects of a meaningful development strategy might be.

411

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

NASA Astrophysics Data System (ADS)

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 of structures associated with BC springs were used to evaluate structural controls on groundwater flow in BC. Geochemical analysis indicates groundwater discharge near Hoover Dam (HD) and along the faulted edge of the Boulder City Pluton is derived from Lake Mead, high ?87Sr Proterozoic or Tertiary crystalline rock and, possibly, Tertiary sedimentary rock. Reducing conditions indicated by 234U/238U and ?34S concentrations suggest the groundwater is confined and/or derived from greater depths while carbon isotopes indicate the groundwater is old. Lighter ?D and ?O-18, modern tritium concentrations, post-Dam U disequilibrium ages, and occurrence of anthropogenic perchlorate support the presence of a young Lake Mead component. South of the pluton, the Lake Mead component is absent. More oxidizing conditions in this part of BC, indicated by the U and S isotope concentrations, suggest the groundwater is less confined and/or derived from shallower depths compared to groundwater discharging near HD. Older apparent groundwater ages and heavier ?D and ?O-18 values south of the pluton indicate slower flow paths from a lower elevation or latitude source. Clarifying the nature of groundwater flow in eastern NV, the analyses indicate that hydraulic connection between the regional carbonate aquifer and BC is unlikely. Instead, the data indicate sources of BC springs are derived relatively locally in CRV and, possibly, south Lake Mead Valley. Results of the geologic and kinematic analyses indicate faults that formed from the interaction of E-W extension related to the AZ extensional corridor and NW-SE trans tension related to the Lake Mead shear zone are the main controls on groundwater flow in the vicinity of HD and Boulder City Pluton. Most groundwater in BC appears to discharge along the NW-striking Palm Tree fault that parallels the northern edge of the pluton. Supported by trends in chemistry, an alignment of similar-elevation springs along a N-S striking fault that extends the length of west BC may be a flow path for groundwater from north BC to south of the pluton. South of the pluton, dikes intrude many of the faults and appear to act as flow barriers. Groundwater in this part of BC may flow through stacked layers of brecciated volcanic rock prevalent in the area. Flow from laterally adjacent valleys into BC would have to cross a N-S structural fabric that is not favored kinematically. Existing information implies an overall absence of significant surface discharge in BC prior to construction of HD. This indicates that the head created by impoundment of the Colorado River has likely pushed old, slow moving groundwater through CRV and, possibly, south Lake Mead Valley, to the surface in BC where it discharges as springs and seeps.

Justet, L.; Beard, S.

2010-12-01

412

Cities Centre University of Toronto  

E-print Network

Cities Centre University of Toronto On the Mandate of the new University of Toronto Cities Centre selections from the Proposal for the Establishment of a Cities Centre at the University of Toronto December and Director, Global Cities Program); Eric Miller (Civil Engineering and Director, Joint Program

Sokolowski, Marla

413

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

414

Inner City Revitalization in Beijing  

Microsoft Academic Search

Under the neo liberal market philosophy of the 1990s, the city is considered a growth engine. City planning and development emphasizes on making the cities productive and as a result, market based revitalization initiatives including real estate, retail and entertainment has become important. Unlike in the past, city revitalization is not limited to the development of the blighted or declining

Shrawan Kumar Acharya

415

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

416

Improvement of corrosion properties in an aluminum-sprayed AZ31 magnesium alloy by a post-hot pressing and anodizing treatment  

Microsoft Academic Search

The corrosion protection afforded by an aluminum arc-spray coating and a post-treatment consisted of hot pressing and anodizing on an AZ31 magnesium alloy has been studied by using polarization and electrochemical impedance techniques. The corrosion current densities of the Al arc-sprayed AZ31 specimens in their spray-coated condition, and after hot pressed under 500 and 1600 MPa conditions, were found to

Liu-Ho Chiu; Chun-Chin Chen; Chih-Fu Yang

2005-01-01

417

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. PMID:23544062

van Raan, Anthony F. J.

2013-01-01

418

PHYSICAL CHARACTERIZATION OF VITREOUS STATE LABORATORY AY102/C106 AND AZ102 HIGH LEVEL WASTE MELTER FEED SIMULANTS (U)  

SciTech Connect

The objective of this task is to characterize and report specified physical properties and pH of simulant high level waste (HLW) melter feeds (MF) processed through the scaled melters at Vitreous State Laboratories (VSL). The HLW MF simulants characterized are VSL AZ102 straight hydroxide melter feed, VSL AZ102 straight hydroxide rheology adjusted melter feed, VSL AY102/C106 straight hydroxide melter feed, VSL AY102/C106 straight hydroxide rheology adjusted melter feed, and Savannah River National Laboratory (SRNL) AY102/C106 precipitated hydroxide processed sludge blended with glass former chemicals at VSL to make melter feed. The physical properties and pH were characterized using the methods stated in the Waste Treatment Plant (WTP) characterization procedure (Ref. 7).

Hansen, E

2005-03-31

419

Regulation of u-PAR gene expression by H2A.Z is modulated by the MEK-ERK/AP-1 pathway  

PubMed Central

The urokinase receptor (u-PAR) which is largely regulated at the transcriptional level has been implicated in tumor progression. In this study, we explored the epigenetic regulation of u-PAR and showed that the histone variant H2A.Z negatively regulates its expression in multiple cell lines. Chromatin immunoprecipitation assays revealed that H2A.Z was enriched at previously characterized u-PAR-regulatory regions (promoter and a downstream enhancer) and dissociates upon activation of gene expression by phorbol ester (PMA). Using specific chemical and dominant negative expression constructs, we show that the MEK–ERK signaling pathway terminating at AP-1 transcription factors intersects with the epigenetic control of u-PAR expression by H2A.Z. Furthermore, we demonstrate that two other AP-1 targets (MMP9 gene and miR-21 microRNA) are also H2A.Z regulated. In conclusion, our work demonstrates that (i) the expression of two genes and a microRNA all implicated in tumor progression are directly regulated by H2A.Z and (ii) MEK–ERK signaling terminating at AP-1 intersects with the epigenetic control of target gene expression by H2A.Z. PMID:21937508

Chauhan, Santosh; Boyd, Douglas D.

2012-01-01

420

Confirmation of fenfluramine effect on 5-HT1B receptor binding of [11C]AZ10419369 using an equilibrium approach  

PubMed Central

Assessment of serotonin release in the living brain with positron emission tomography (PET) may have been hampered by the lack of suitable radioligands. We previously reported that fenfluramine caused a dose-dependent reduction in specific binding in monkeys using a classical displacement paradigm with bolus administration of [11C]AZ10419369. The aim of this study was to confirm our previous findings using an equilibrium approach in monkey. A total of 24 PET measurements were conducted using a bolus infusion protocol of [11C]AZ10419369 in three cynomolgus monkeys. Initial PET measurements were performed to assess suitable Kbol values. The fenfluramine effect on [11C]AZ10419369 binding was evaluated in a displacement and pretreatment paradigm. The effect of fenfluramine on [11C]AZ10419369 binding potential (BPND) was dose-dependent in the displacement paradigm and confirmed in the pretreatment paradigm. After pretreatment administration of fenfluramine (5.0?mg/kg), the mean BPND of the occipital cortex decreased by 39%, from 1.38ą0.04 to 0.84ą0.09. This study confirms that the new 5-HT1B receptor radioligand [11C]AZ10419369 is sensitive to fenfluramine-induced changes in endogenous serotonin levels in vivo. The more advanced methodology is suitable for exploring the sensitivity limit to serotonin release as measured using [11C]AZ10419369 and PET. PMID:22167236

Finnema, Sjoerd J; Varrone, Andrea; Hwang, Tzung-Jeng; Halldin, Christer; Farde, Lars

2012-01-01

421

THE REDSHIFT AND NATURE OF AzTEC/COSMOS 1: A STARBURST GALAXY AT z = 4.6  

SciTech Connect

Based on broadband/narrowband photometry and Keck DEIMOS spectroscopy, we report a redshift of z = 4.64{sup +0.06}{sub -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 {mu}m), CSO/SHARC II (350 {mu}m), and CARMA and PdBI (3 mm). We do not detect CO(5 {yields} 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{sigma} upper limits on the gas mass to {approx}<8 x 10{sup 9} M{sub sun} and {approx}<5 x 10{sup 10} M{sub sun}, respectively (assuming similar conditions as observed in z {approx} 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 ({approx}<50 Myr), massive (M{sub *} {approx} 10{sup 11} M{sub sun}), but compact ({approx}<2 kpc) galaxy, forming stars at a rate of {approx}1300 M{sub sun} yr{sup -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.

Smolcic, V. [European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching b. Muenchen (Germany); Capak, P.; Blain, A. W.; Salvato, M.; Masters, D.; Moric, I.; Riechers, D. A. [California Institute of Technology, MC 249-17, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Ilbert, O. [Laboratoire d'Astrophysique de Marseille, Universite de Provence, CNRS, BP 8, Traverse du Siphon, 13376 Marseille Cedex 12 (France); Aretxaga, I.; Hughes, D. [Instituto Nacional de Astrofisica, Optica y Electronica (INAOE), Aptdo. Postal 51 y 216, 72000 Puebla, Pue. (Mexico); Schinnerer, E. [Max Planck Institut fuer Astronomie, Koenigstuhl 17, Heidelberg D-69117 (Germany); Sheth, K. [Spitzer Science Center, 314-6 Caltech, 1201 East California Boulevard, Pasadena, CA 91125 (United States); Aravena, M. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Aussel, H. [UMR AIM (CEA-UP7-CNRS), CEA-Saclay, Orme des Merisiers, bt. 709, F-91191 Gif-sur-Yvette Cedex (France); Aguirre, J. [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); Berta, S. [Max-Planck-Institut fuer extraterrestrische Physik, Postfach 1312, 85741 Garching (Germany); Carilli, C. L. [National Radio Astronomy Observatory, P.O. Box 0, Socorro, NM 87801-0387 (United States); Civano, F.; Fazio, G.; Huang, J. [Harvard-Smithsonian Centre for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2011-04-20

422

Mechanisms of plastic deformation in AZ31 magnesium alloy investigated by acoustic emission and transmission electron microscopy  

Microsoft Academic Search

The effect of deformation conditions on plastic deformation and acoustic emission (AE) in hot-rolled magnesium alloy AZ31 has been investigated in the temperature range of 20–200°C by constant strain rate tensile tests. Two sets of samples differing in the preheating temperature before individual passes of hot rolling have been studied. Both the yield stress and the tensile strength decrease with

Miloš Jane?ek; Robert Král; Patrik Dobro?; František Chmelík; Vladimír Šupík; Frank Holländer

2007-01-01

423

Mechanical and fracture properties of an AZ91 Magnesium alloy reinforced by Si and SiC particles  

Microsoft Academic Search

A commercial AZ91 magnesium alloy (nominal composition Mg–9%Al; 1%Zn; 0.3%Mn, balance Mg in weight percent) reinforced with SiC particles and modified by the addition of Si has been used in this study. Formation of an “in situ” composite (Mg–Mg2Si) results in strong bonding between Mg2Si and the matrix interface. Samples were deformed in compression in the temperature interval from room

Z. Trojanová; V. Gärtnerová; A. Jäger; A. Námešný; M. Chalupová; P. Pal?ek; P. Luká?

2009-01-01

424

Effect of submicron size SiC particulates on microstructure and mechanical properties of AZ91 magnesium matrix composites  

Microsoft Academic Search

In the present study, AZ91 magnesium matrix composites reinforced with six volume fractions (0.5, 1, 1.5, 2, 3 and 5vol.%) of submicron-SiC particulates (0.2?m) were fabricated by stir casting. The as-cast ingots were forged at 420°C with 50% reduction, and then extruded at 370°C with the ratio of 16 at a constant ram speed of 15mm\\/s. The microstructure of the

K. K. Deng; K. Wu; Y. W. Wu; K. B. Nie; M. Y. Zheng

2010-01-01

425

9.28 Bedrock Rivers KX Whipple and RA DiBiase, Arizona State University, Tempe, AZ, USA  

E-print Network

9.28 Bedrock Rivers KX Whipple and RA DiBiase, Arizona State University, Tempe, AZ, USA BT Crosby 550 9.28.1.1 Definition and Occurrence 551 9.28.1.2 Importance of Bedrock Rivers 551 9.28.1.3 Relation of Flow Hydraulics 552 9.28.2.2 Controls on the Width of Bedrock Rivers 553 9.28.3 Erosion Processes

Crosby, Benjamin T.

426

Corrosion resistance of AZ91D magnesium alloy with electroless plating pretreatment and Ni–TiO 2 composite coating  

Microsoft Academic Search

In this paper, a protective multilayer coating, with electroless Ni coating as bottom layer and electrodeposited Ni–TiO2 composite coating as top layer, was successfully prepared on AZ91D magnesium alloy by a combination of electroless and electrodeposition techniques. Scanning electron microscopy and X-ray diffraction were employed to investigate the surface, cross-section morphologies and phase structure of coatings, respectively. The electrochemical corrosion

Shiyan Zhang; Qing Li; Xiaokui Yang; Xiankang Zhong; Yan Dai; Fei Luo

2010-01-01

427

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

428

Structure and formation mechanism of phosphate conversion coating on die-cast AZ91D magnesium alloy  

Microsoft Academic Search

Phosphate conversion coating, which is considered as an alternative to chromium conversion coating for improving the corrosion resistance of die-cast AZ91D magnesium alloy is studied. The structure and formation mechanism of the coating was investigated in details using ESEM\\/EDX, XRD, EPMA, ICP and electrochemical method. It was found that the conversion coating was composed of complex phosphate containing magnesium and

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

2008-01-01

429

The influence of manganese on the microstructure and mechanical properties of AZ31 gravity die cast alloys  

Microsoft Academic Search

Calculated phase diagrams for the Mg–Al–Zn–Mn system indicate that ?-Mn(Al) and Al8Mn5 can primarily crystallize during the solidification of Mn-modified AZ31. Both phases may act as potential heterogeneous nucleants for Mg grains and thus as potential grain refiners in the Mg–Al system. In this investigation three Mg–3Al–1Zn alloys with different Mn content were die cast and hot rolled at 450°C.

T. Laser; M. R. Nürnberg; A. Janz; Ch. Hartig; D. Letzig; R. Schmid-Fetzer; R. Bormann

2006-01-01

430

Top coating of low-molecular weight polymer MALPB used for enhanced protection on anodized AZ31B Mg alloys  

Microsoft Academic Search

A protective composite coating on an AZ31B magnesium alloy was prepared by anodic oxidation to form an oxide layer, followed\\u000a by single immersion in maleic anhydride-g-liquid polybutadiene (MALPB) solution to cover a polymer coating on top. As a low-molecular weight polymer with low viscosity,\\u000a MALPB had a tendency to infiltrate into the pores and cracks in the anodic layer to

Jinwei Wang; Jinwei Tang; Yedong He

2010-01-01

431

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

432

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.

433

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.

434

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

435

Engineers Week: Future City  

NSDL National Science Digital Library

The National Engineers Week Future City Competition provides âÂÂa fun and exciting educational engineering program for seventh- and eighth-grade students that combines a stimulating engineering challenge with a âÂÂhands-onâ application to present their vision of a city of the future.â The competition is intended to foster engineering skills, such as teamwork, communication and problem solving skills, as well as to inspire students to explore future careers in engineering. Using the commercial software SIMCITY to design their ideal city, students interact with each other, and with teachers and engineer mentors and also learn about the multi-disciplines within the engineering profession. The website has more information about the competition, as well as a handbook providing helpful tips and techniques. Examples of accomplishments from previous competitions are posted and CD-ROM video is available from regional coordinators to give more background on the competition.

436

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

437

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.

438

Cities and Buildings Database  

NSDL National Science Digital Library

The University of Washington Libraries Digital Collection online projects and archives are well-regarded, and this database proves to be no exception to that highly positive trend. Started in 1995, the Cities and Buildings Database contains over 10,000 digitized images of buildings and cities culled from all historical periods and from all over the world. Visitors may wish to start with a simple keyword search or if they are interested in merely browsing by country, they may do so as well from the homepage. Of course, one should not be surprised to also learn that visitors may also perform detailed searches for buildings by city, style, title, architect, and date of construction. Just to give prospective visitors some sense of the depth and breadth of the collection, the database contains everything from conceptual sketches of Frank Gehry's Experience Music Project to photographs of the monastery of St. Keghard in Armenia.

439

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

440

Rate sensitivity and tension-compression asymmetry in AZ31B magnesium alloy sheet.  

PubMed

The constitutive response of a commercial magnesium alloy rolled sheet (AZ31B-O) is studied based on room temperature tensile and compressive tests at strain rates ranging from 10(-3) to 10(3)?s(-1). Because of its strong basal texture, this alloy exhibits a significant tension-compression asymmetry (strength differential) that is manifest further in terms of rather different strain rate sensitivity under tensile versus compressive loading. Under tensile loading, this alloy exhibits conventional positive strain rate sensitivity. Under compressive loading, the flow stress is initially rate insensitive until twinning is exhausted after which slip processes are activated, and conventional rate sensitivity is recovered. The material exhibits rather mild in-plane anisotropy in terms of strength, but strong transverse anisotropy (r-value), and a high degree of variation in the measured r-values along the different sheet orientations which is indicative of a higher degree of anisotropy than that observed based solely upon the variation in stresses. This rather complex behaviour is attributed to the strong basal texture, and the different deformation mechanisms being activated as the orientation and sign of applied loading are varied. A new constitutive equation is proposed to model the measured compressive behaviour that captures the rate sensitivity of the sigmoidal stress-strain response. The measured tensile stress-strain response is fit to the Zerilli-Armstrong hcp material model. PMID:24711496

Kurukuri, Srihari; Worswick, Michael J; Ghaffari Tari, Dariush; Mishra, Raja K; Carter, Jon T

2014-05-13

441

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. PMID:22393239

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

2012-01-01

442

Effects of Compression-Pass on Microstructure and Mechanical Properties of AZ80 Alloy  

NASA Astrophysics Data System (ADS)

In the present work, as-homogenized AZ80 alloy was subjected to the multi-pass compression at the same total compression strain and different compression passes. The effects of compression-pass on microstructure and mechanical properties were investigated. Results show that the intermittent reheating stage during the multi-pass compression process plays an important role in the microstructure evolution. During the intermittent reheating process, the fine grains in the duplex-grain microstructure generated by partial dynamic recrystallization grow rapidly, which lead to the increase of the average grain size and the decrease of the difference in grain size between the coarse and fine grains. This phenomenon is more obvious by the increase of the intermittent reheating stage. It finds that the hardness mainly depends on the average grain size, and the value decreases with the increase of the average grain size. However, the ultimate tensile strength and elongation mainly depends on the grain size distribution, and the better tensile properties can be obtained when the microstructure is more homogenous.

Meng, Mu; Zhao, Xi; Zhang, Zhimin; Qiang, Wang

2014-09-01

443

Time Dependent Magnesium AZ31B Behavior: Experimental and Physically based Modeling Investigation  

NASA Astrophysics Data System (ADS)

The need to produce vehicles with improved fuel efficiency and reduced emissions has led the automotive industry to consider use of “lightweighting” materials in the construction of automotive body and chassis systems. For automotive body structures and closure panel applications, mostly made of sheet, aluminum alloys are being introduced due to their lower densities and relatively high specific strengths, as well as their compatibility with the traditional manufacturing process that are used with steel. However, interest has been increasingly focusing on the use of sheet magnesium in the manufacturing of panels and structural components, since its density is about 40% lower compared to aluminum. Accordingly, the objectives of this study are to investigate the evolution of microstructure during thermo-mechanical processing of twin-roll cast AZ31B alloys sheets, and to examine the mechanical properties of the alloy under superplastic conditions. The rate dependent crystal plasticity model have been used and integrated using an explicit model was coupled with the Taylor polycrystal model in the aim to capture the overall behavior of our studied material.

Rodriguez, A. K.; Ayoub, G.; Kridli, G.; Zbib, H.

444

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

445

Failure analysis of AZ31 magnesium alloy sheets based on the extended GTN damage model  

NASA Astrophysics Data System (ADS)

Based on the Gurson-Tvergaard-Needleman (GTN) model and Hill's quadratic anisotropic yield criterion, a combined experimental-numerical study on fracture initiation in the process of thermal stamping of Mg alloy AZ31 sheets was carried out. The aim is to predict the formability of thermal stamping of the Mg alloy sheets at different temperatures. The presented theoretical framework was implemented into a VUMAT subroutine for ABAQUS/EXPLICIT. Internal damage evolution due to void growth and coalescence developed at different temperatures in the Mg alloy sheets was observed by scanning electron microscopy (SEM). Moreover, the thermal effects on the void growth, coalescence, and fracture behavior of the Mg alloy sheets were analyzed by the extended GTN model and forming limit diagrams (FLD). Parameters employed in the GTN model were determined from tensile tests and numerical iterative computation. The distribution of major and minor principal strains in the specimens was determined from the numerical results. Therefore, the corresponding forming limit diagrams at different stress levels and temperatures were drawn. The comparison between the predicted forming limits and the experimental data shows a good agreement.

Wang, Rui-ze; Chen, Zhang-hua; Li, Yu-jie; Dong, Chao-fang

2013-12-01

446

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

447

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

NASA Astrophysics Data System (ADS)

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

Liu, Yi; Wu, Xin

2007-06-01

448

Relation between cooling rates and microstructures in gravity-die-cast AZ91D disks  

SciTech Connect

In-die temperature measurements during the casting of 3.5- and 11.7-mm-thick disks in metal dies at 100 C, 200 C, and 400 C enables calculating of the heat flux from the casting to the die as a function of the casting parameters. Using the flux so determined, the temperature field in the plates could be calculated in agreement with measured values. Increasing preheating temperatures reduced the heat flux, which extended the local solidification time and coarsened the structure. Directional solidification, from the wall of the die to the center of the disk, took place only when casting a thin disk in a die at 400 C, because of the combination of low undercooling (which prevents homogeneous nucleation) and a sufficiently steep temperature gradient at the solidification front to ensure directional growth. A relatively long residence time at the high temperature, as occurs during casting in a die at 400 C, leads to a more-uniform distribution of the Al, due to diffusion in the solid, and prevents the divorced eutectic, distinct from that obtained at slow solidification, of the AZ91D ingot.

Avishei, A.; Bamberger, M. [Technion, Haifa (Israel). Dept. of Materials Engineering

1999-08-01

449

Molecular and catalytic properties of 2,4'-dihydroxyacetophenone dioxygenase from Burkholderia sp. AZ11.  

PubMed

The gene dad encoding 2,4'-dihydroxyacetophenone (DHAP) dioxygenase was cloned from Burkholderia sp. AZ11. The initiation codon GTG was converted to ATG for high-level expression of the enzyme in Escherichia coli. The enzyme was moderately thermostable, and the recombinant enzyme was briefly purified. The enzyme (M(r)=90 kDa) was a homotetramer with a subunit M(r) of 23 kDa. It contained 1.69 mol of non-heme iron, and had a dark gray color. On anaerobic incubation of it with DHAP, the absorption at around 400 nm increased due to the formation of an enzyme-DHAP complex. Multiple sequence alignment suggested that His77, His79, His115, and Glu96 in the cupin fold were possible metal ligands. The apparent K(m) for DHAP and the apparent V(max) were estimated to be 1.60 ľM and 6.28 ľmol/min/mg respectively. 2-Hydroxyacetophenone was a poor substrate. CuCl(2) and HgCl(2) strongly inhibited the enzyme, while FeSO(4) weakly activated it. PMID:22451401

Enya, Mayu; Aoyagi, Keiko; Hishikawa, Yoshihiro; Yoshimura, Azusa; Mitsukura, Koichi; Maruyama, Kiyofumi

2012-01-01

450

Histone variant selectivity at the transcription start site: H2A.Z or H2A.Lap1.  

PubMed

Considerable attention has been given to the understanding of how nucleosomes are altered or removed from the transcription start site of RNA polymerase II genes to enable transcription to proceed. This has led to the view that for transcriptional activation to occur, the transcription start site (TSS) must become depleted of nucleosomes. However, we have shown that this is not the case with different unstable histone H2A variant-containing nucleosomes occupying the TSS under different physiological settings. For example, during mouse spermatogenesis we found that the mouse homolog of human H2A.Bbd, H2A.Lap1, is targeted to the TSS of active genes expressed during specific stages of spermatogenesis. On the other hand, we observed in trophoblast stem cells, a H2A.Z-containing nucleosome occupying the TSS of genes active in the G 1 phase of the cell cycle. Notably, this H2A.Z-containing nucleosome was different compared with other promoter specific H2A.Z nucleosomes by being heterotypic rather than being homotypic. In other words, it did not contain the expected two copies of H2A.Z per nucleosome but only one (i.e., H2A.Z/H2A rather than H2A.Z/H2A.Z). Given these observations, we wondered whether the histone variant composition of a nucleosome at an active TSS could in fact vary in the same cell type. To investigate this possibility, we performed H2A.Z ChIP-H2A reChIP assays in the mouse testis and compared this data with our testis H2A.Lap1 ChIP-seq data. Indeed, we find that different promoters involved in the expression of genes involved in distinct biological processes can contain either H2A.Z/H2A or H2A.Lap1. This argues that specific mechanisms exist, which can determine whether H2A.Z or H2A.Lap1 is targeted to the TSS of an active gene. PMID:24213378

Nekrasov, Maxim; Soboleva, Tatiana A; Jack, Cameron; Tremethick, David J

2013-01-01

451

Transient Liquid Phase Diffusion Bonding of Magnesium Alloy (Mg-AZ31) to Titanium Alloy (Ti-6Al-4V)  

NASA Astrophysics Data System (ADS)

The magnesium alloy Mg-AZ31 and titanium alloy Ti-6Al-4V have physical characteristics and mechanical properties that makes it attractive for a wide range of engineering applications in the aerospace and automotive industries. However, the differences in melting temperature and coefficient of thermal expansion hinder the use of traditional fusion welding techniques. Transient liquid phase (TLP) bonding of magnesium alloy Mg-AZ31 and titanium alloy Ti-6Al- 4V was performed and different interlayer types and configurations were used to facilitate joint formation. The joining of these alloys using Ni foils was successful at a bonding temperature of 515°C, bonding pressure 0.2 MPa, for bonding time of 5 minutes. At the Ni/Mg-AZ31 bond interface, the formation of a eutectic liquid between Mg and Ni was observed. The formation of Mg2Ni and Mg3AlNi2 were identified along the bond interface resulting in an isothermally solidified joint. At the Ni/Ti-6Al-4V interface, the solid-state diffusion process results in joint formation. The use of double Ni-Cu sandwich joint resulted in further enhancement in joint formation and this produced joints with greater shear strength values. The configuration of Mg-AZ31/Cu- Ni/Ti-6Al-4V or Mg-AZ31/Ni-Cu/Ti-6Al-4V influence the mechanism of bonding and the type of intermetallics formed within the joint. The application of thin Ni electrodeposited coatings resulted in further enhancements of joint quality due to better surface-to-surface contact and a reduction in the formation of intermetallics at the joint. The effect of Cu nano-particles in the coatings was found to decrease the eutectic zone width and this resulted in an increase the shear strength of the joints. The highest shear strength of 69 MPa was possible with bonds made using coatings containing Cu nano-particle dispersion.

Atieh, Anas Mahmoud

452

Vilnius City Theriofauna  

Microsoft Academic Search

Mammal diversity investigations in Vilnius were carried out in 1992, 1998–2004. The following 51 mammal species were registered in the city: five species of insectivores (Insectivora), 11 of bats (Chiroptera), 18 of rodents (Rodentia), two of hares (Lagomorpha), 11 of carnivores (Carnivora) and four of ungulates (Artiodactyla). Fourteen mammal species are included into the Red Data Book of Lithuania, namely

Kazimieras Baranauskas; Linas Bal?iauskas; Reda Mažeikyt?

2005-01-01

453

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

454

TELECOM-CITIES  

NSDL National Science Digital Library

TELECOM-CITIES, a discussion list sponsored by the Taub Urban Research Center at New York University, focuses on practical and theoretical aspects of the impacts of advanced telecommunications and telematics on urban centers. A web-based subscription form is available.

1997-01-01

455

CITY COUNCIL ORDINANCE NUMBER # -09 ORDINANCE OF THE CITY COUNCIL OF THE CITY OF UNION CITY  

E-print Network

Energy Efficiency Standards," adopted by the Stopwaste.Org org Board on April 22, 2009 and made a part potential in Union City is moderate. These local features contribute to the Bay Area's status & Recycling Board (StopWaste.Org) and the Alameda County Conference of Mayors launched the Alameda County

456

Bug City: Beetles [Videotape].  

ERIC Educational Resources Information Center

"Bug City" is a video series created to help children learn about insects and other small critters. All aspects of bug life are touched upon including body structure, food, habitat, life cycle, mating habits, camouflage, mutualism (symbiosis), adaptations, social behavior, and more. Each program features dramatic microscopic photography, fun…

1998

457

Bug City: Ants [Videotape].  

ERIC Educational Resources Information Center

"Bug City" is a video series created to help children (grades 1-6) learn about insects and other small critters. All aspects of bug life are touched upon including body structure, food, habitat, life cycle, mating habits, camouflage, mutualism (symbiosis), adaptations, social behavior, and more. Each program features dramatic microscopic…

1998

458

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

459

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

460

unrestricted Optimizing City Traffic  

E-print Network

No overtakings allowed [1] R.M. Colombo,P. Goatin and M.D Rosini, On the modeling and Management of Traffic #12unrestricted Optimizing City Traffic using Time-Expanded Graphs Orange Labs SĂŠbastien FELIX traffic using Time-Expanded Graphs section 1 Introduction section 2 Existing approaches section 3 Proposed

461

Summer in the City  

ERIC Educational Resources Information Center

This article describes the different experiences of the participants in an Outward Bound-sponsored "urban expedition" to New York City that was designed to make them better teachers by examining their beliefs and biases. The participants in this "urban expedition" came from schools that work with Outward Bound USA, the Garrison, New York,…

Gewertz, Catherine

2005-01-01

462

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

463

Bug City: Bees [Videotape].  

ERIC Educational Resources Information Center

"Bug City" is a video series created to help children learn about insects and other small critters. All aspects of bug life are touched upon including body structure, food, habitat, life cycle, mating habits, camouflage, mutualism (symbiosis), adaptations, social behavior, and more. Each program features dramatic microscopic photography, fun…

1998

464

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

465

City model enrichment  

NASA Astrophysics Data System (ADS)

The combination of mobile communication technology with location and orientation aware digital cameras has introduced increasing interest in the exploitation of 3D city models for applications such as augmented reality and automated image captioning. The effectiveness of such applications is, at present, severely limited by the often poor quality of semantic annotation of the 3D models. In this paper, we show how freely available sources of georeferenced Web 2.0 information can be used for automated enrichment of 3D city models. Point referenced names of prominent buildings and landmarks mined from Wikipedia articles and from the OpenStreetMaps digital map and Geonames gazetteer have been matched to the 2D ground plan geometry of a 3D city model. In order to address the ambiguities that arise in the associations between these sources and the city model, we present procedures to merge potentially related buildings and implement fuzzy matching between reference points and building polygons. An experimental evaluation demonstrates the effectiveness of the presented methods.

Smart, Philip D.; Quinn, Jonathan A.; Jones, Christopher B.

466

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

467

City Schools under Attack.  

ERIC Educational Resources Information Center

Public education is under attack. There is a general assault on the public sphere as a central aspect of our common existence. The problems of city schools stem from our failure to place educational reform within a broader vision of social and economic justice and our unwillingness to take political action to realize that vision. (MLH)

Molnar, Alex

1994-01-01

468

GPHY 421 Sustainable Cities Prof. Ulrich Kamp 1 SUSTAINABLE CITIES  

E-print Network

GPHY 421 ­ Sustainable Cities ­ Prof. Ulrich Kamp 1 SUSTAINABLE CITIES (GPHY 421) - Fall 2011 of sustainability efforts in cities around the world. Topics include, for example, urban sprawl and smart growth, alternative energy, public transportation, integrated waste management, integrated water management, green

Vonessen, Nikolaus

469

SPECIAL MEETING AGENDA CITY COUNCIL OF THE CITY OF CERRITOS  

E-print Network

TO THE CERRITOS REDEVELOPMENT AGENCY MONDAY - NOVEMBER 18, 2013 - CITY HALL - 7:00 P.M. COUNCIL CHAMBERS on this Agenda are available for public inspection at the City Clerk's Office, Cerritos City Hall, 18125 AMENDING THE DEVELOPMENT STANDARDS OF AUTOMOBILE DEALERSHIP SIGNS. (COUNCIL) Development Code Amendment

470

Lesson 3: Ybor City, “Cigar City of the World”  

Microsoft Academic Search

After it was established and continued to thrive, Ybor city was a multiethnic, multiracial, industrial community unlike any other in Florida at the time. This lesson explores the city’s unique history, with special emphasis on the Cuban community that settled there.

Samantha Cook

2012-01-01

471

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

472

University of Minnesota Twin Cities  

E-print Network

University of Minnesota Twin Cities Emergency Operations Plan Š 2011 Regents of the University of Minnesota. All rights reserved. Revision 5.0, September 2011 #12;University of Minnesota - Twin Cities - Twin Cities Emergency Operations Plan Revision 5.0 TABLE OF CONTENTS Basic Plan Introduction Purpose

Amin, S. Massoud

473

New York City's Education Battles  

ERIC Educational Resources Information Center

When Bloomberg gave his first State of the City address, in January, 2002, he announced his intention to seek mayoral control of the schools and abolish the infamous New York City Board of Education, which he called "a rinky-dink candy store." He joined a long list of New York mayors, educators, and business leaders who believed that the city's…

Meyer, Peter

2008-01-01

474

El Paso City Directories  

NSDL National Science Digital Library

Urbanologists and other students of the urban condition can walk through the world of 1888 El Paso via this website. It is certainly a rather unusual "walk," as the digitized city directories offer just a taste of the cultural and social milieu at the time, but they remain remarkable documents. These early city directories date from 1885 to 1905, and their digitization was made possible by a grant to the El Paso County Historical Society from the Robert E. and Evelyn McKee Foundation. The project is housed at the University of Texas at El Paso (UTEP) Libraries, and visitors can browse through the documents at their leisure. The directories (in most cases) include business and personal entries, and one can only imagine the historical or literary potential of such material.

475

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.

476

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.

477

Lost City Expedition  

NSDL National Science Digital Library

This website provides an account of a research cruise to the Lost City Hydrothermal Field at the summit of the Atlantis Massif. During this 32-day expedition, scientists onboard the research vessel Atlantis explored active limestone chimneys that rise 200 feet above the seafloor. This site features information about the biology, chemistry and geology of the Lost City area, as well as explanations of the instruments used to sample and analyze these parameters. It also describes how researchers used the robotic Autonomous Benthic Vehicle and three-person submarine Alvin to explore, map and sample the sea floor. The site also includes a daily shipboard journal, a glossary, and an ask-a-scientist online form. This extensive site provides in-depth, broadly accessible information about the science, mapping and operations of this expedition and hydrothermal systems in general.

Washington, University O.

478

Exploring small city maps.  

PubMed

The exploration of city maps has exploded recently due to the wide availability, increasing use of, and reliance on small positioning and navigational devices for personal use. In this study, subjects explored small, 3-mile diameter circular maps exemplifying five different types of street networks common in the United States, in order to locate a hypothetical city hall. Chosen locations indicated that subjects are able to identify more accessible sites. Monitoring eye position revealed that women explored maps faster, using more widely dispersed but more narrowly focused gaze clusters than men. The type of street network influenced the time spent by the eyes in a locale and differentially affected the size of gaze clusters between women and men, underscoring the complex interactions of gender-specific strategies with street network types. PMID:22990289

Christova, Peka; Scoppa, Martin; Peponis, John; Georgopoulos, Apostolos P

2012-11-01

479

Pittsburgh City Photographer  

NSDL National Science Digital Library

The Archives Service Center and the Digital Research Library at the University of Pittsburgh have made over 1,200 pictures of Pittsburgh taken by the Pittsburgh City Photographer between 1901 and 1969 available online. Included are views of Pittsburgh parks and recreation facilities, athletic and mayoral events, general street scenes and traffic, as well as interior and exterior shots of familiar Pittsburgh buildings, including some that have been demolished. There are also interesting depictions of home life, and the famous and not so famous people of Pittsburgh. For example, a search on Highland Park retrieves 20 images dating from 1901 - 1968, and includes families at the Childrens' Zoo in the 1960s; various views of the entrance to Highland Park; an early image of the Highland Park Reservoir (1907); and DeLucca's market on Bryant St. It is also possible to search the Pittsburgh City Photographer's Collection along with 26 other image collections at the Historic Pittsburgh Image Collections.

480

City of Chicago Landmarks  

NSDL National Science Digital Library

The city of Chicago has many hundreds of wonderful architectural landmarks and this helpful website is a great resource for anyone with an interest in such matters. On the site, visitors can start by checking out the Landmarks Tours to get started. There over a dozen tours here, including Mansions Tour, Art Deco Tour, and Pre-Fire Chicago Tour. Moving on, visitors may also wish to look over the Architects area. Here they will encounter some of the usual suspects (Frank Lloyd Wright, Louis Sullivan, etc.) and learn about some lesser-known architects, such as Solon S. Beman and William W. Boyington, who designed the wonderful entrance to Rosehill Cemetery. The Style Guide offers a great primer for those who'd like to know more about two dozen architectural styles, including Craftsman, International, and Tudor Revival. Finally, the site also includes a Listings area, complete with information about all of the buildings on the city's official landmarks list.

481

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.

482

URBZ: User Generated Cities  

NSDL National Science Digital Library

The User Generated Cities organization (URBZ) "facilitates the production and exchange of information, knowledge, ideas and practices towards better cities for all." With offices in Mumbai and Geneva, URBZ deploys a variety of web-based tools "for the production and sharing of information by residents and stakeholders." On their homepage, visitors can read postings from staff members on the construction of multi-story buildings in the developing world and sustainable architecture design charrettes. Moving on, visitors can learn more about URBZ by clicking on the "Workshops" section. Here they will find diagrams and explanations of URBZ's design philosophy and their work with local communities. Interested parties can also sign up here to receive email updates and to learn more about their upcoming events.

483

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.

484

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

485

Plastic Deformation Characteristics Of AZ31 Magnesium Alloy Sheets At Elevated Temperature  

SciTech Connect

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

2007-05-17

486

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