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1

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

Federal Register 2010, 2011, 2012, 2013

...on the navigable waters of the Colorado River in Bullhead City, Arizona for...on the navigable waters of the Colorado River in Bullhead City, AZ. The proposed...would include the waters of the Colorado River between Davis Camp and...

2012-06-19

2

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

Federal Register 2010, 2011, 2012, 2013

...on the navigable waters of the Colorado River in Bullhead City, Arizona for...on the navigable waters of the Colorado River in Bullhead City, AZ. This temporary...closure of the portion of the Colorado River for this annual event. The...

2013-07-23

3

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

Federal Register 2010, 2011, 2012, 2013

...on the navigable waters of the Colorado River in Bullhead City, Arizona for...on the navigable waters of the Colorado River in Bullhead City, AZ. The proposed...would include the waters of the Colorado River between Davis Camp and...

2013-06-07

4

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

Federal Register 2010, 2011, 2012, 2013

...on the navigable waters of the Colorado River in Bullhead City, Arizona for...on the navigable waters of the Colorado River in Bullhead City, Arizona. The...would include the waters of the Colorado River between Davis Camp to Rotary...

2011-07-01

5

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

Federal Register 2010, 2011, 2012, 2013

...Coast Guard 33 CFR Part 100 [Docket No. USCG-2012-0954] Special Local Regulation; Annual Marine Events on the Colorado River Between Davis Dam (Bullhead City, AZ) and Headgate Dam (Parker, AZ) Within the San Diego Captain of the...

2012-11-23

6

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

Federal Register 2010, 2011, 2012, 2013

...Coast Guard 33 CFR Part 100 [Docket No. USCG-2012-0925] Special Local Regulation; Annual Marine Events on the Colorado River, Between Davis Dam (Bullhead City, AZ) and Headgate Dam (Parker, AZ) Within the San Diego Captain of the...

2012-11-13

7

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

Federal Register 2010, 2011, 2012, 2013

...Special Local Regulation; Annual Marine Events on the Colorado River, Between Davis Dam (Bullhead City, AZ) and Headgate...Ski Race Special Local Regulation located upon the Colorado River from 8 a.m. through 5 p.m. on March 9 and...

2013-03-01

8

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

Code of Federal Regulations, 2013 CFR

...false Annual Firework Events on the Colorado River, between Davis Dam (Bullhead...1124 Annual Firework Events on the Colorado River, between Davis Dam (Bullhead...includes all navigable waters of the lower Colorado River at Laughlin, NV encompassed by...

2013-07-01

9

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

Code of Federal Regulations, 2013 CFR

... false Annual marine events on the Colorado River, between Davis Dam (Bullhead...1102 Annual marine events on the Colorado River, between Davis Dam (Bullhead...Regulated Area That portion of the lower Colorado River on the Arizona side between...

2013-07-01

10

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...1102 Marine Events on the Colorado River, between Davis Dam (Bullhead... Where: that portion of the Colorado River starting from the entrance...

2009-07-01

11

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...1102 Marine Events on the Colorado River, between Davis Dam (Bullhead... Where: that portion of the Colorado River starting from the entrance...

2010-07-01

12

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

Federal Register 2010, 2011, 2012, 2013

...and effective September 15, 2012 is amended as follows: Paragraph 6006 En route domestic airspace areas. * * * * * ANM AZ E6 Tuba City, AZ [New] Tuba City VORTAC, AZ (Lat. 36[deg]07'17'' N., long. 111[deg]16'11'' W.) That...

2013-03-19

13

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

Federal Register 2010, 2011, 2012, 2013

...in the Federal Register May 29, 2013 that establishes Class E en route airspace at the Tuba City VHF Omni-Directional Radio Range...published a final rule in the Federal Register establishing Class E en route airspace at the Tuba City VORTAC, Tuba City, AZ (78...

2013-08-08

14

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...City, Arizona in support of the Desert Storm Shootout. This temporary safety zone is...Lake Racer LLC is sponsoring the Desert Storm Shootout, which is to be held on the...

2013-03-25

15

Bullhead acidizing succeeds offshore California  

SciTech Connect

High acid-injection rates, within the friction dominant region, proved successful in stimulating oil wells completed in a naturally fractured reservoir. The bullhead technique was effective without any chemical or mechanical diversion. Chevron U.S.A. Production Co.'s Santa Clara field produces through wells on Platform Grace, in 318 ft of water. After repeated unsuccessful attempts to stimulate these wells, three basic types of formation damage were discovered: Drilling mud invasion; Solids precipitation; and Emulsion blocks. Accurate identification of the damage, in 1989, led to the first successful stimulation response 9 years after the first completion. One of the keys to successfully acidizing the Monterey is to treat the damaged zones with the stimulation fluids. The paper describes the three formation damages mechanisms, and treatment design including surfactants, acid volumes, retarding and sequestering, and wettability restoration. Acid placement, fluid dynamics, and results are also discussed.

Juprasert, M.S. (Chevron U.S.A. Production Co., Bakersfield, CA (United States))

1994-04-11

16

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

Federal Register 2010, 2011, 2012, 2013

...temporary safety zone within the navigable waters of Thompson...in Lake Havasu, AZ for the Lucas Oil Drag Boat Racing Series. This temporary...to provide safety for the racers, crew, spectators...SEARCH.'' Click on Open Docket Folder on the...

2013-10-02

17

Habitat Suitability Index Models: Black Bullhead  

USGS Publications Warehouse

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

Stuber, Robert J.

1982-01-01

18

Black Bullhead: An Indicator of the Presence of Chemical Carcinogens.  

National Technical Information Service (NTIS)

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 wer...

J. M. Grizzle

1986-01-01

19

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...

20

Auditory Sensitivity in the Bullhead Catfish (Ictalurus Nebulosis).  

National Technical Information Service (NTIS)

The auditory sensitivity of 4 specimens of the bullhead catfish (Ictalurus nebulosis) was determined by shock-avoidance training in an aquatic shuttle box. The range of hearing extended from 100 to 4000 cycles per second, with the maximum sensitivity arou...

G. M. Hartig B. A. Weiss W. F. Strother

1969-01-01

21

Metabolism of chrysene by brown bullhead liver microsomes.  

PubMed

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

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

2003-01-01

22

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

23

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, ...

24

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

25

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

PubMed

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

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

2012-09-26

26

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 ...

27

The riddle of hepatic neoplasia in brown bullheads from relatively unpolluted waters in New York State.  

PubMed

Since 1985, pathologists at Cornell University have investigated the causes of lesions in freshwater fish throughout New York waters in order to clarify possible impairment of fish health by environmental contaminants. Fishermen and biologists alerted us to several relatively protected reservoirs and ponds in which we have found no evidence of elevated levels of anthropogenic environmental contaminants but in which up to 100% of brown bullheads exhibited skin neoplasia. Complete necropsies and histologic study revealed that over 30% of mature brown bullheads from some of these sites had benign or malignant hepatocellular or biliary liver neoplasia. Up to 50% of brown bullheads had benign or malignant liver neoplasia in other relatively unpolluted waters with no evidence of skin neoplasia in bullheads. Multiple samplings of brown bullheads from several of these sites have revealed puzzling variability in the prevalence of skin, liver, and other neoplasia in these fish populations. The cause of these striking epizootics of neoplasia in brown bullheads in unpolluted waters in New York State remains unclear. We hypothesize that natural carcinogens such as N-nitroso compounds formed in aquatic sediments or radon from geologic formations may contribute to epizootic fish neoplasia in New York waters. PMID:8772257

Spitsbergen, J M; Wolfe, M J

28

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

SciTech Connect

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

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

2000-02-01

29

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

USGS Publications Warehouse

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

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

2001-01-01

30

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

31

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

32

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

EPA Science Inventory

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

33

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

Microsoft Academic Search

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

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

1999-01-01

34

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,...

35

Serum Chemistry and Histopathological Evaluations of Brown Bullheads ('Ameiurus nebulosus') from the Buffalo and Niagara Rivers, New York.  

National Technical Information Service (NTIS)

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

L. C. Folmar G. R. Gardner J. Hickey S. Bonomelli T. Moody

1993-01-01

36

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

Microsoft Academic Search

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

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

1983-01-01

37

The influence of calcium concentration on the distribution of the river bullhead Cottus gobio L. (Teleostes, Cottidae)  

Microsoft Academic Search

The influence of some environmental parameters, i.e. dissolved oxygen, water temperature, Ca concentration, pH, conductibility, on populations of the river bullhead, Cottus gobio, in Northern Apennines (Tuscany) has been considered. The bullhead seemed to prefer waters with low levels of calcium. The Discriminant Function Analysis (DFA) showed congruent results and highlighted the role of calcium concentration and pH levels in

A. Nocita; A. Massolo; M. Vannini; G. Gandolfi

2009-01-01

38

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

SciTech Connect

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

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

1999-04-01

39

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

40

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

Microsoft Academic Search

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

Xuan Yang; Paul C. Baumann

2006-01-01

41

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

PubMed

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

Kontula, T; Väinölä, R

2001-08-01

42

Temperament in bullheads: do laboratory and field explorative behaviour variables correlate?  

NASA Astrophysics Data System (ADS)

The relevance of temperament traits for life history strategy or productivity is increasingly acknowledged. Temperament traits are often either observed in captivity or in the wild, but studies combining both observations are very rare. We examine whether exploratory behaviour in the bullhead ( Cottus perifretum), assayed under laboratory conditions, predicts this behaviour under field conditions. Forty-three PIT-tagged individuals were first assayed for exploration of a novel environment in the aquarium and then released into an unfamiliar stream stretch, where they were later relocated using a mobile antenna. Explorative behaviour assayed in the laboratory was significantly positively related to the exploration in the field, thus predicting distance moved in the field release. Both in the laboratory and in the field, explorative behaviour was not related to individual body length. When bullheads that did not leave the refuge in the aquarium (laboratory assay) and, therefore, did not explore the new environment were excluded from the analysis, the correlation between laboratory and field explorative behaviour variables became weaker. However, overall, our results illustrate that exploration rate of bullheads in isolated single-individual experiments can be used to predict this behaviour in the natural ecosystem.

Kobler, Alexander; Engelen, Brecht; Knaepkens, Guy; Eens, Marcel

2009-10-01

43

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

44

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…

Nicholson, Rob

2000-01-01

45

AZ-101 Mixer Pump Test.  

National Technical Information Service (NTIS)

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-liqu...

G. T. Maclean

2002-01-01

46

Metabolism of Benzo(a)Pyrene and Persistence of DNA Adducts in the Brown Bullhead 'Ictalurus nebulosus'.  

National Technical Information Service (NTIS)

The in vitro metabolism of ((3)H)benzo(a)pyrene (BP) and ((14)C)benzo(a)pyrene-7,8-dihydrodiol (BP-7,8-diol) by liver of brown bullhead (Ictalurus nebulosus) was characterized, as was the formation and persistence of BP-DNA adducts in vivo. Compared to ra...

H. C. Sikka A. R. Steward C. Kandaswami J. P. Rutkowski J. Zaleski

1991-01-01

47

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

EPA Science Inventory

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

48

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

Microsoft Academic Search

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

Vicki S. Blazer; Sean D. Rafferty; Paul C. Baumman; Stephen B. Smith; Eric C. Obert

2009-01-01

49

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

EPA Science Inventory

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

50

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

51

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

52

Correlation between the surface chemistry and the atmospheric corrosion of AZ31, AZ80 and AZ91D magnesium alloys  

NASA Astrophysics Data System (ADS)

X-ray photoelectron spectroscopy (XPS) was used in order to investigate the correlation between the surface chemistry and the atmospheric corrosion of AZ31, AZ80 and AZ91D magnesium alloys exposed to 98% relative humidity at 50 °C. Commercially pure magnesium, used as the reference material, revealed MgO, Mg(OH) 2 and tracers of magnesium carbonate in the air-formed film. For the AZ80 and AZ91D alloys, the amount of magnesium carbonate formed on the surface reached similar values to those of MgO and Mg(OH) 2. A linear relation between the amount of magnesium carbonate formed on the surface and the subsequent corrosion behaviour in the humid environment was found. The AZ80 alloy revealed the highest amount of magnesium carbonate in the air-formed film and the highest atmospheric corrosion resistance, even higher than the AZ91D alloy, indicating that aluminium distribution in the alloy microstructure influenced the amount of magnesium carbonate formed.

Feliu, S., Jr.; Pardo, A.; Merino, M. C.; Coy, A. E.; Viejo, F.; Arrabal, R.

2009-01-01

53

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.

Baumann, P C; Harshbarger, J C

1995-01-01

54

Serum chemistry and histopathological evaluations of brown bullheads ( Ameiurus nebulosus ) from the Buffalo and Niagara Rivers, New York  

Microsoft Academic Search

Cholangiomas and cholangiocarcinomas were observed in brown bullheads (Ameiurus nebulosus) collected from the Buffalo and Niagara Rivers (NY) and Old Woman Creek (OH), USA. Significant increases in serum blood urea\\u000a nitrogen, uric acid, triglycerides, inorganic phosphate, ALT, LDL, calcium, and iron and a significant decrease in cholesterol\\u000a were found in the fish from the Buffalo and Niagara Rivers compared to

L. C. Folmar; G. R. Gardner; J. Hickey; S. Bonomelli; T. Moody

1993-01-01

55

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

PubMed

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 (> or = 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 prevalence in Anacostia bullheads warrants concern and was similar to those at 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. PMID:11392129

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

2001-06-01

56

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

SciTech Connect

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

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

1997-02-01

57

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

2013-03-12

58

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

PubMed Central

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

2009-01-01

59

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

Federal Register 2010, 2011, 2012, 2013

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

2012-04-03

60

Az amlodipin\\/valsartan kombináció költséghatékonysági elemzése a hipertónia kezelésében  

Microsoft Academic Search

Tanulmányunk célja az Exforge tabletta - egy amlo- dipin\\/valsartan kombináció - költségeinek, hatékonysá- gának és költséghatékonyságának elemzése a magas vérnyomás kezelésében. Komparátornak a két hatóanyag szabad kombinációját választottuk, mivel az Exforge olyan hipertenzióban szenvedô betegek kezelésére java- solt, akiknek a vérnyomását nem lehet megfelelôen beál- lítani az amlodipin vagy valsartan monoterápiákkal, és számukra a két gyógyszer szabad kombinációjú kezelése javasolt.

Kósa József

2007-01-01

61

KORSZER? RÁDIÓFELDERÍTÉS KIHÍVÁSAI AZ INFORMÁCIÓS M?VELETEKBEN  

Microsoft Academic Search

Absztrakt Az új biztonságpolitikai helyzetben számos új kihívás és veszély jelent meg, amelyek természetszer?leg új védelmi megoldásokat, eszközöket és rendszereket követelnek a védelmi szférától is. A megfelel? válaszlépések magukba kell, hogy foglalják azokat a korszer?, az információs technológia által nyújtott új lehet?ségeket, amelyek a távközlés, a személyi kommunikáció, a radartechnika, az adatátvitel, a navigáció és más elektronikai berendezések, rendszerek révén

Fürjes János; Zrínyi Miklós Nemzetvédelmi Egyetem

2008-01-01

62

An investigation of carbonic anhydrase activity in the gills and blood plasma of brown bullhead ( Ameiurus nebulosus ), longnose skate ( Raja rhina ), and spotted ratfish ( Hydrolagus colliei )  

Microsoft Academic Search

Separated plasma and whole blood non-bicarbonate buffering capacities, together with plasma and gill carbonic anhydrase activities and endogenous plasma carbonic anhydrase inhibitor activity were investigated in three species of fish: the brown bullhead (Ameiurus nebulosus), a teleost; the longnose skate (Raja rhina), an elasmobranch; and the spotted ratfish (Hydrolagus colliei), a chimaeran. The objective was to test the hypothesis that

Kathleen M. Gilmour; Bina Shah; Cheryl Szebedinszky

2002-01-01

63

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

64

Dendritic solidification of magnesium alloy AZ91  

Microsoft Academic Search

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

K. Pettersen; O. Lohne; N. Ryum

1990-01-01

65

The AzTEC mm-wavelength camera  

Microsoft Academic Search

AzTEC is a mm-wavelength bolometric camera utilizing 144 silicon nitride micromesh detectors. Here, we describe the AzTEC instrument architecture and its use as an astronomical instrument. We report on several performance metrics measured during a three-month observing campaign at the James Clerk Maxwell Telescope and conclude with our plans for AzTEC as a facility instrument on the Large Millimetre Telescope.

G. W. Wilson; J. E. Austermann; T. A. Perera; K. S. Scott; P. A. R. Ade; J. J. Bock; J. Glenn; S. R. Golwala; S. Kim; Y. Kang; D. Lydon; P. D. Mauskopf; C. R. Predmore; C. M. Roberts; K. Souccar; M. S. Yun

2008-01-01

66

Computer simulation of the leaching and washing of waste in tanks C-106, AY-102, AZ-101, and AZ-102  

SciTech Connect

The waste in underground storage tanks C-106, AY-102, AZ-101, and AZ-102 will be used to prepare feed material for the proposed high level waste vitrification demonstration plant at Hanford. A chemical process simulation computer program called the Environment Simulation Program (ESP) was used to estimate the compositions and quantities of this waste and the products after pretreatment processing. The amount of precipitated material in Tank C-106 predicted to be dissolved by sluicing is 27 wt.%. The amount of precipitated material predicted to be dissolved by mild leaching is about 30% for the C-106 and AY-102 combined waste and about 50% for AZ-101, and 35% for AZ-102 wastes. The predicted caustic solution raw material requirements for leaching are 158 m{sup 3} for C-106 and AY-102, 60 m{sup 3} for AZ-101, and 146 m{sup 3} for AZ-102, all as 50 wt.% NAOH.

MacLean, G.T.

1997-05-01

67

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

68

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

Microsoft Academic Search

This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for vapor samples obtained during the operation of the tank 241-AZ-101 and 241-AZ-102 airlift circulators (ALCs) and during the initial operation (''bump'') of the tank 241-AZ-101 mixer pumps. The purpose of the ALC operation is to support portions of the operational

1999-01-01

69

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

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

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

70

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

71

702AZ aging waste ventilation facility year 2000 test procedure  

SciTech Connect

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

Winkelman, W.D.

1998-07-22

72

AZ ÖKOMARKETING GYAKORLATI MEGVALÓSULÃSA AZ ÉLELMISZER-GAZDASÃGBAN  

Microsoft Academic Search

Az Európai Unióba való belépésünkkel a környezetvédelem, a fenntartható fejlődés minden területen nagyobb hangsúlyt kap. Különösen igaz ez az élelmi-szer-gazdaságra. Azok a kutatások is felértékelődhetnek ennek tükrében, ame-lyek a környezet-gazdaságtan különböző területein folynak. A szerző évek óta foglalkozik az ökomarketing elméleti és módszertani kérdéseivel, kutatásának eredményeit kétrészes tanulmányban adja közre. A tanulmány első részében arra vállalkozott, hogy a nemzetközi szakiroda-lom

Maria Szolnoki Gyozone Karkus

2005-01-01

73

Mucosubstance histochemistry in control and acid-stressed epidermis of brown bullhead catfish, Ictalurus nebulosus (LeSueur).  

PubMed

Glycoprotein components of epidermal mucous cells in control (pH 6.8) and acid-stressed (pH 5.8, 4.8, 4.0) brown bullhead catfish were studied by histochemical and autoradiographic methods. Following exposure to acid, increased numbers of epidermal mucous cells were noted in all tissue sites studied, particularly dorsal and ventral skin. Mucous cells of control fish and acid-stressed (pH 5.8) fish contained a mixture of neutral and acidic mucosubstances, the latter including both sialomucins and sulfomucins, with sialomucins predominating. An apparent shift toward increased sulfomucin production was observed in skin from fish exposed to pH 4.8 and 4.0. In addition, autoradiographic studies using 35S showed increased labeling of mucous cells in acid-exposed (pH 4.0) epidermis, offering further support for a shift toward sulfomucin production in acid-stressed fish. Absence of appreciable sulfomucin production in younger fish (less than 1 year old) suggested that this shift may be partly age-dependent. The functional significance of increased sulfomucin production in acid-stressed epidermal mucous cells is uncertain but may be related to maintenance of ionic equilibrium. PMID:4073548

Zuchelkowski, E M; Pinkstaff, C A; Hinton, D E

1985-08-01

74

Mucosubstance histochemistry in control and acid-stressed epidermis of brown bullhead catfish, Ictalurus nebulosus (LeSueur)  

SciTech Connect

Glycoprotein components of epidermal mucous cells in control (pH 6.8) and acid-stressed (pH 5.8, 4.8, 4.0) brown bullhead catfish were studied by histochemical and autoradiographic methods. Following exposure to acid, increased numbers of epidermal mucous cells were noted in all tissue sites studied, particularly dorsal and ventral skin. Mucous cells of control fish and acid-stressed (pH 5.8) fish contained a mixture of neutral and acidic mucosubstances, the latter including both sialomucins and sulfomucins, with sialomucins predominating. An apparent shift toward increased sulfomucin production was observed in skin from fish exposed to pH 4.8 and 4.0. In addition, autoradiographic studies using /sup 35/S showed increased labeling of mucous cells in acid-exposed (pH 4.0) epidermis, offering further support for a shift toward sulfomucin production in acid-stressed fish. Absence of appreciable sulfomucin production in younger fish (less than 1 year old) suggested that this shift may be partly age-dependent. The functional significance of increased sulfomucin production in acid-stressed epidermal mucous cells is uncertain but may be related to maintenance of ionic equilibrium.

Zuchelkowski, E.M.; Pinkstaff, C.A.; Hinton, D.E.

1985-08-01

75

[4-Androstene-3,17-dione metabolism in vitro in the liver microsomes of species of bullhead endemic to Lake Baikal under normal conditions and in mono-oxygenase induction by 3-methylcholanthrene and aroclor 1254].  

PubMed

The metabolism in vitro of 4-androstene 3,17-dione--one of the steroid hormones--has been studied in liver microsomes of three species of bullhead: Cottocomephorus grewingki Dyb., Paracottus Kneri Dyb., Paracottus Kessleri Dyb. from Lake Baikal under norm and under induction of monooxygenases by 3-methylcholanthrene and arochlore 1254. The metabolism in vitro 4-androstene 3,17-dione in liver microsomes depends on fish sex, species and gonadal maturation. The rate of androstendione hydroxylation reliably decreases at monooxydase system induction of endoplasmic reticulum in bullhead liver before spawning and during spawning periods by 3-methylcholanthrene and arochlore 1254. PMID:8507738

Viner, R I; Kupchinski?, A B

1993-01-01

76

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

SciTech Connect

This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for vapor samples obtained during the operation of the tank 241-AZ-101 and 241-AZ-102 airlift circulators (ALCs) and during the initial operation (''bump'') of the tank 241-AZ-101 mixer pumps. The purpose of the ALC operation is to support portions of the operational test procedure (OTP) for Project W-030 (OTP-W030-001) and to perform functional test in support of Project W-151. Project W-030 is the 241-A-702 ventilation upgrade project (241-142-702) and Project W-151 is the 241-AZ-101 Mixer Pump Test. The functional tests will check the operability of the tank 241-AZ-101 ALCs. Process Memo's No. 2E98-082 and No. 2E99-001 (LMHC 1999a, LMHC 1999b) direct the operation of the ALCs and the Industrial Hygiene monitoring respectively. A series of tests will be conducted in which the ALCs in tanks 241-AZ-101 and 241-AZ-102 will be operated at different air flow rates. Vapor samples will be obtained to determine constituents that may be present in the tank headspace during ALC operation at tanks 241-AZ-101 and 241-AZ-102 as the waste is disturbed. During the testing, vapor samples will be obtained from the headspace of tanks 241-AZ-101 and 241-AZ-102 via the unused port on the standard hydrogen monitoring system (SHMS). In addition the last two vapor samples will be collected from the headspace of tank 241-AZ-101 during the operation of the mixer pumps. Each mixer pump will be operated for approximately 5 minutes. Results will be used to provide the waste feed delivery program with environmental air permitting data for tank waste disturbing activities. Because of radiological concerns, the samples will be filtered for particulates. It is recognized that this may remove some organic compounds. The following sections provide the general methodology and procedures to be used in the preparation, retrieval, transport, analysis, and reporting of results from vapor samples retrieved during the ALC testing.

TEMPLETON, A.M.

1999-12-07

77

In vitro response of the brown bullhead catfish (BB) and rainbow trout (RTG-2) cell lines to benzo[ a]pyrene  

Microsoft Academic Search

Established cell lines from rainbow trout (RTG-2) and brown bullhead catfish (BB) were evaluated as bioindicators of benzo[a]pyrene (B[a]P) toxicity with 3-(4,5-dimethyltiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) reduction and neutral red (NR) uptake assays. Cytochrome P450 1A1 (CYP1A1) enzymatic activity was also evaluated, and taken as a biological indicator of the B[a]P induction power by ethoxyresorufin O-deethylase (EROD) and ethoxycoumarin O-deethylase (ECOD)

C. S. A. Araújo; S. A. F. Marques; M. J. T. Carrondo; L. M. D. Gonçalves

2000-01-01

78

Corrosion Protection of Magnesium Alloy AZ31B.  

National Technical Information Service (NTIS)

Corrosion rates for bare and coated Magnesium alloy AZ31B have been measured. Two coatings, Dow-23(Trademark) and Tagnite(Trademark), have been tested by electrochemical methods and their effectiveness determined. Electrochemical methods employed were the...

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

1997-01-01

79

Investment casting of AZ91HP magnesium alloy  

Microsoft Academic Search

This paper describes AZ91HP magnesium alloy investment casting. The aim of this study is to optimize the process for magnesium\\u000a investment casting. Special attention was given to evaluating the thermal stability of oxides against molten AZ91HP magnesium\\u000a alloy. The oxides examined included CaO, CaZr03, and silica bonded A1203 and ZrSi04. Also, the microstructural features of the as-cast alloy were investigated,

Shaekwang Kim; Myounggyun Kim; Taewhan Hong; Heekook Kim; Youngjig Kim

2000-01-01

80

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

Microsoft Academic Search

This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for vapor samples obtained during the operation of the tank 241-AZ-101 and 241-AZ-102 airlift circulators (ALCs). The purpose of the ALC operation is to support portions of the operational test procedure (OTP) for Project W-030 (OTP-W030-001) and to perform functional test

1999-01-01

81

241-AZ-101 pump removal trough analysis  

SciTech Connect

As part of the current Hanford mission of environmental cleanup, various long length equipment must be removed from highly radioactive waste tanks. The removal of equipment will utilize portions of the Equipment Removal System for Project W320 (ERS-W320), specifically the 50 ton hydraulic trailer system. Because the ERS-W320 system was designed to accommodate much heavier equipment it is adequate to support the dead weight of the trough, carriage and related equipment for 241AZ101 pump removal project. However, the ERS-W320 components when combined with the trough and its` related components must also be analyzed for overturning due to wind loads. Two troughs were designed, one for the 20 in. diameter carriage and one for the 36 in. diameter carriage. A proposed 52 in. trough was not designed and, therefore is not included in this document. In order to fit in the ERS-W320 strongback the troughs were design with the same widths. Structurally, the only difference between the two troughs is that more material was removed from the stiffener plates on the 36 in trough. The reduction in stiffener plate material reduces the allowable load. Therefore, only the 36 in. trough was analyzed.

Coverdell, B.L.

1995-10-17

82

Spatial coding of semantic information: knowledge of country and city names depends on their geographical proximity  

Microsoft Academic Search

Summary We report the case of a patient, A.Z., with a refractory disorder of semantic processing. Using a number of spo- ken word-written word matching paradigms, her com- prehension of the broad proper nouns category of place names was investigated. In addition to being sensitive to temporal factors, A.Z.'s ability to identify country or city names accurately was significantly worse

Sebastian J. Crutch; Elizabeth K. Warrington

2003-01-01

83

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

...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...

2009-01-01

84

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

...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...

2010-01-01

85

Electroless Nickel Phosphorus Plating on AZ31  

NASA Astrophysics Data System (ADS)

One of the major drawbacks to using magnesium parts in automotive applications is poor corrosion resistance, which can be improved with a nickel-boron coating placed on a nickel-phosphorus coating, which, in turn, is placed on a phosphate-permanganate conversion-coating layer produced on the magnesium alloy AZ31. This work reports on the determination of the optimum kinetic parameters for producing a coherent nickel-phosphorus coating using an electroless-procedure phosphate-permanganate conversion-coating layer and for studying the effects of the experimental variables of the electroless plating process on the phosphorus content, surface morphology, and structure of the electroless nickel-phosphorus (EN-P) coatings produced. Measurements of the plating rate as a function of experimental variables such as the compositions of the plating bath constituents, temperature, and pH were implemented using the weight-gain method; the phosphorus content of the EN-P coatings was measured using energy-dispersive spectroscopy (EDS) analysis. The surface morphology of the coating was examined using a scanning electron microscope (SEM); X-ray diffraction (XRD) was used to characterize the structure of each coating. An empirical rate law was determined for EN-P plating on a phosphate-permanganate conversion coating. It is found that the deposition rate of the EN-P coating increases by increasing the deposition temperature, the concentration of free nickel ions, and the concentration of hypophosphite ions in the plating bath. In addition, the deposition rate decreases by increasing both the plating bath pH and the concentration of citric acid in the plating bath.

Shartal, Kh. M.; Kipouros, G. J.

2009-04-01

86

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

Federal Register 2010, 2011, 2012, 2013

...Zone; Great Western Tube Float; Colorado River; Parker, AZ AGENCY: Coast Guard...on the navigable waters of the Colorado River in Parker, Arizona for the Great...on the navigable waters of the Colorado River in Parker, AZ. This...

2013-06-05

87

21. Streetscape, South Coronado Boulevard, looking northwest AZ205 (F. D. ...  

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

21. Streetscape, South Coronado Boulevard, looking northwest AZ-205 (F. D. Connor House) is the first house on the left - Clifton Townsite, Confluence of Chase Creek & San Francisco River, Clifton, Greenlee County, AZ

88

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

89

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

90

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

PubMed

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

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

2010-02-01

91

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

Federal Register 2010, 2011, 2012, 2013

...D AND E AIRSPACE AREAS; AIR TRAFFIC SERVICE...Class E airspace areas extending upward...or more above the surface of the earth. * * * * * AWP AZ...700 feet above the surface within a 6.5-mile...Class E airspace area. That airspace...

2011-04-04

92

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

PubMed

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

Trolander, Judith Ann

2011-01-01

93

Nature of the 1100 Micron AzTEC-COSMOS Sources  

NASA Astrophysics Data System (ADS)

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

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

2006-12-01

94

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

95

Multiaxial fatigue of extruded AZ61A magnesium alloy  

Microsoft Academic Search

Strain-controlled multiaxial fatigue experiments were conducted on extruded AZ61A magnesium alloy using thin-walled tubular specimens in ambient air. The experiments included fully reversed tension–compression, cyclic torsion, proportional axial-torsion, and 90° out-of-phase axial-torsion. For the same equivalent strain amplitude, fatigue life under proportional loading was the highest and the nonproportional loading resulted in the shortest fatigue life. Detectable kinks were identified

Qin Yu; Jixi Zhang; Yanyao Jiang; Qizhen Li

2011-01-01

96

Recycle City  

NSDL National Science Digital Library

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

1997-01-01

97

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 Aramis© Optical strain measurement system has been used to obtain principle forming limit strain. The Forming Limit Diagram (FLD) is obtained by the critical point on the specimen surface at various temperatures. It is shown that the forming limit curve is higher at high temperature. Based on the Voce law model, finite element simulations of deep drawing test have been done with the commercial finite element code FORGE® in order to investigate the feasibility of hot stamping process for AZ31. In the simulation, the punch load and the thickness distributions have been studied. Meanwhile, the cross-shaped cup deep drawing simulations have been conducted with the data provided in the conference Website. The similar conclusion are obtained that the formability of AZ31 improve at high temperature and the simulation is effective in hot stamping processing. The study results are helpful for the application of the stamping technology for the magnesium alloy sheet [3].

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

2011-08-01

98

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

Microsoft Academic Search

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

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

2005-01-01

99

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

100

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

Microsoft Academic Search

This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for samples obtained from tank 241-AZ-102.

2000-01-01

101

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

102

Cities Guide  

NSDL National Science Digital Library

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

2001-01-01

103

Modelling of Superplastic Forming of AZ31 Magnesium Alloy  

NASA Astrophysics Data System (ADS)

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.

2011-01-01

104

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

105

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

Code of Federal Regulations, 2010 CFR

...Flight Rules in the Vicinity of the Grand Canyon National Park, AZ Federal ...Flight Rules in the Vicinity of the Grand Canyon National Park, AZ Section 1...following airspace, designated as the Grand Canyon National Park Special Flight...

2010-01-01

106

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

Code of Federal Regulations, 2010 CFR

...Flight Rules in the Vicinity of the Grand Canyon National Park, AZ Federal ...Flight Rules in the Vicinity of the Grand Canyon National Park, AZ Section 1...following airspace, designated as the Grand Canyon National Park Special Flight...

2009-01-01

107

Electrochemical noise analysis of the corrosion of AZ91D magnesium alloy in alkaline chloride solution  

Microsoft Academic Search

The corrosion behavior of AZ91D magnesium alloy in alkaline chloride solution was investigated by electrochemical noise (EN). The wavelet transform, as well as noise resistance (Rn) and power spectral density (PSD), had been employed to analyze the EN data. It was revealed that there exist three different stages of corrosion for AZ91D magnesium alloy in alkaline chloride solution, including an

Tao Zhang; Yawei Shao; Guozhe Meng; Fuhui Wang

2007-01-01

108

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

Microsoft Academic Search

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

1999-01-01

109

Effect of Pb and Sb additions on the precipitation kinetics of AZ91 magnesium alloy  

Microsoft Academic Search

Effect of Pb and Sb additions on the precipitation sequence and ageing kinetics of AZ91 alloy has been studied using the differential thermal analyzer, optical microscopy and scanning electron microscopy. The precipitation sequence in the AZ91 alloy is not altered whereas the enthalpy required for dissolution of ? phases changes with respect to the individual additions of Pb and Sb.

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

2007-01-01

110

Flow softening behavior during high temperature deformation of AZ31Mg alloy  

Microsoft Academic Search

In the present study, the flow softening behavior occurring during high temperature deformation of AZ31 Mg alloy was investigated. Flow softening of AZ31 Mg alloy was considered to arise mainly due to thermal softening by deformation heating and microstructural softening by dynamic recrystallization (DRX). Artificial neural networks method was used to derive the accurate amounts of thermal softening by deformation

Byoung Ho Lee; N. S. Reddy; Jong Taek Yeom; Chong Soo Lee

2007-01-01

111

Simulation of Deformation Twinningin Extruded AZ31 Mg AlloyBarsusing the Crystal Plasticity FEM  

Microsoft Academic Search

Uniaxial compression tests on extruded AZ31 Mg alloy bars were carried out to investigate the evolution of deformation twins and deformation texture during plastic deformation. Electron back-scattered diffraction (EBSD) analysis was used to examine the orientation of parent grains and twin bands in AZ31 Mg alloy under uniaxial compression. A crystal plasticity finite element method (CPFEM) that takes both crystallographic

S. H. Choi; N. Y. Ham; A. Jung; B. S. Seong

2011-01-01

112

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

Microsoft Academic Search

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

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

2007-01-01

113

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

Microsoft Academic Search

This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for vapor samples obtained during the operation of mixer pumps in tank 241-AZ-101. The primary purpose of the mixer pump test (MPT) is to demonstrate that the two 300 horsepower mixer pumps installed in tank 241-AZ-101 can mobilize the settled sludge

2000-01-01

114

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

Microsoft Academic Search

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

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

2011-01-01

115

TiC\\/AZ91D composites fabricated by in situ reactive infiltration process and its tensile deformation  

Microsoft Academic Search

An innovative processing route was adopted to fabricate 42.1%(volume fraction) TiC\\/AZ91D magnesium matrix composites. The reinforcement TiC was in situ synthesized from elemental powders of Ti and C and the matrix magnesium alloy AZ91D pressurelessly infiltrated into the preform of Ti and C. A comparative tensile deformation tests were conducted on the as-synthesized TiC\\/AZ91D composites and magnesium alloy AZ91D. The

Ji-jie WANG; Jin-hua GUO; Li-qing CHEN

2006-01-01

116

H2A.Z Functions To Regulate Progression through the Cell Cycle†  

PubMed Central

Histone H2A variants are highly conserved proteins found ubiquitously in nature and thought to perform specialized functions in the cell. Studies in yeast on the histone H2A variant H2A.Z have shown a role for this protein in transcription as well as chromosome segregation. Our studies have focused on understanding the role of H2A.Z during cell cycle progression. We found that htz1? cells were delayed in DNA replication and progression through the cell cycle. Furthermore, cells lacking H2A.Z required the S-phase checkpoint pathway for survival. We also found that H2A.Z localized to the promoters of cyclin genes, and cells lacking H2A.Z were delayed in the induction of these cyclin genes. Several different models are proposed to explain these observations.

Dhillon, Namrita; Oki, Masaya; Szyjka, Shawn J.; Aparicio, Oscar M.; Kamakaka, Rohinton T.

2006-01-01

117

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

PubMed

The histone variant H2A.Z has been implicated in the regulation of gene expression, and in plants antagonizes DNA methylation. Here, we ask whether a similar relationship exists in mammals, using a mouse B-cell lymphoma model, where chromatin states can be monitored during tumorigenesis. Using native chromatin immunoprecipitation with microarray hybridization (ChIP-chip), we found a progressive depletion of H2A.Z around transcriptional start sites (TSSs) during MYC-induced transformation of pre-B cells and, subsequently, during lymphomagenesis. In addition, we found that H2A.Z and DNA methylation are generally anticorrelated around TSSs in both wild-type and MYC-transformed cells, as expected for the opposite effects of these chromatin features on promoter competence. Depletion of H2A.Z over TSSs both in cells that are induced to proliferate and in cells that are developing into a tumor suggests that progressive loss of H2A.Z during tumorigenesis results from the advancing disease state. These changes were accompanied by increases in chromatin salt solubility. Surprisingly, ?30% of all genes showed a redistribution of H2A.Z from around TSSs to bodies of active genes during the transition from MYC-transformed to tumor cells, with DNA methylation lost from gene bodies where H2A.Z levels increased. No such redistributions were observed during MYC-induced transformation of wild-type pre-B cells. The documented role of H2A.Z in regulating transcription suggests that 30% of genes have the potential to be aberrantly expressed during tumorigenesis. Our results imply that antagonism between H2A.Z deposition and DNA methylation is a conserved feature of eukaryotic genes, and that transcription-coupled H2A.Z changes may play a role in cancer initiation and progression. PMID:20709945

Conerly, Melissa L; Teves, Sheila S; Diolaiti, Daniel; Ulrich, Michelle; Eisenman, Robert N; Henikoff, Steven

2010-08-13

118

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

Federal Register 2010, 2011, 2012, 2013

...facilitate vectoring of Instrument Flight Rules (IFR) aircraft under control of Denver, Albuquerque...This improves the safety and management of IFR operations in the vicinity of the VORTAC...action aids in containing aircraft while in IFR conditions under control of Denver,...

2013-05-29

119

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.

120

Beautiful city  

Microsoft Academic Search

Proponents of the City Beautiful movement advocated for sizable public investments in monumental spaces, street beautification, and classical architecture. Today, economists and policymakers see the provision of consumer leisure amenities as a way to attract people and jobs to cities. But past studies have provided only indirect evidence of the importance of leisure amenities for urban growth and development. In

Gerald Carlino

2009-01-01

121

Social Cities  

Microsoft Academic Search

Humans are social animals: relationships are critical to our wellbeing. Indeed, a lack of face-to-face contact can put our health at risk. This report looks at ways to make cities better places to live by increasing our opportunities to connect with other people. It examines how the design and functioning of a city – from transport networks to the availability

Jane-Frances Kelly; Peter Breadon; Caitrin Davis; Amelie Hunter; Peter Mares; Daniel Mullerworth; Tom Quinn; Ben Weidmann

2012-01-01

122

Conformal AZ5214-E resist deposition on patterned (1 0 0) InP substrates  

NASA Astrophysics Data System (ADS)

A draping technique was studied to deposit thin, visco-elastic AZ5214-E resist layers from a water surface over planar and patterned substrates. A visco-elastic AZ5214-E layer forms on the water surface when a drop of AZ5214-E makes contact with it. The drop spreads out within a fraction of a second because of a large positive difference in surface tension between water and AZ5214-E. The spreading mechanism lies in the ability of PGMEA (AZ5214-E liquid constituent) to form hydrogen bonds with water. We brought AZ5214-E drops to make contact with water at 20 ± 0.1 °C via adhesive forces to form AZ5214-E layers on the water surface of (1) circular and (2) square shapes. In case (1), the layers, formed from drops of V = 3 µl, had thickness t ap c sdot 4V/??-2 for ? < 32 mm, and t > c sdot 4V/??-2 for larger ?. In case (2), the layers had t ap a + bV for V between 7 and 12 µl on square-shaped water surfaces of constant area A = 34.5 mm × 34.5 mm. All layers exhibited microscopic waviness with an average thickness uniformity u ~ 91%, and submicron waviness with a root-mean-square roughness ? ~ 12 nm and a lateral correlation length ? ~ 32 µm. AZ5214-E sheets coated conformally high mesa objects with sharp convex and concave edges: 61 µm high ridges confined to ~35°-inclined facets and 9 µm high ridges confined to negatively sloped facets. The draping technique can be used to deposit conformal AZ5214-E layers over non-planar substrates for non-planar device processing.

Eliás, P.; Gregusová, D.; Martaus, J.; Kostic, I.

2006-02-01

123

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

124

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

125

An 18-Inch Direct Drive Alt-Az Telescope  

NASA Astrophysics Data System (ADS)

A modest aperture alt-az telescope has been designed and is being built for student use at California Polytechnic State University. The telescope's drive system has no gears, belts, or friction wheels; instead direct drive motors and high resolution encoders are completely integrated into the bearing assemblies and telescope superstructure. In altitude, for instance, a ring of permanent magnets is firmly mounted to the OTA while an opposing ring of coils is mounted on the inside of a fork arm. The electronic control system has been designed to operate these brushless motors in a high- precision mode. To achieve the highest possible closed loop servo bandwidth, the structure was designed -- using finite element analysis as well as traditional tools -- to have a very high natural frequency. The direct drive system and stiff structure should effectively counter wind gusts when the telescope is operated out in the open or within a roll-off roof observatory.

Genet, Russell M.; Rowe, Dave; Gray, Dan; Albertson, Billy; Chiu, Wilson; Kirkup, Michelle; Murphy, Drew; Ridgely, John; Schmitt, Josh; Swanson, Matt; Urban, Rob; Liu, Tong; Branch, Howard; Chelborad, Cary; Keller, Allan

2008-05-01

126

Plasma electrolytic oxidation coating on AZ91 magnesium alloy modified by neodymium and its corrosion resistance  

Microsoft Academic Search

Ceramic coatings on the surfaces of Mg-9Al-1Zn (AZ91) magnesium alloy and Mg-9Al-1Zn-1Nd magnesium alloy (AZ91 magnesium alloy modified by neodymium, named as AZ91Nd in this paper) are synthesized in aluminate electrolyte by plasma electrolytic oxidation (PEO) process, respectively. X-ray diffraction and X-ray photoelectron spectroscopy analyses show the PEO coating on the Mg-9Al-1Zn-1Nd alloy comprises not only MgO and Al2O3, which

Y. L. Song; Y. H. Liu; S. R. Yu; X. Y. Zhu; Q. Wang

2008-01-01

127

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

128

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

SciTech Connect

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

BRIGGS, S.R.

2000-02-25

129

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

130

Virtual City  

NSDL National Science Digital Library

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

1994-01-01

131

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

National Technical Information Service (NTIS)

This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for samples obtained from tank 241-AZ-102. The purpose of this sampling event is to ...

J. H. Rasmussen

1999-01-01

132

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

National Technical Information Service (NTIS)

This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for samples obtained from tank 241-AZ-102. The purpose of this sampling event is to ...

A. M. Templeton

1999-01-01

133

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

134

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

Federal Register 2010, 2011, 2012, 2013

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

2013-10-31

135

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

SciTech Connect

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

Robinson, R.S.

1996-10-30

136

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

SciTech Connect

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

ANDREWS, J.E.

2000-03-28

137

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

138

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

PubMed

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

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

2011-03-01

139

Charge exchange, excitation, and ionization in AZ++H(1s) collisions in strong magnetic fields  

Microsoft Academic Search

The effects of strong magnetic fields ( Btilde 104T) on charge exchange, excitation, and ionization processes in collisions of H(1s) atoms with fully stripped ions AZ+ are studied by the classical trajectory Monte Carlo method in the energy range 25-2000keV\\/u . The cases B&ar;||v&ar; and B&ar;?v&ar; , where v&ar; is the velocity vector of AZ+ ion, are considered. It was

B. He; J. G. Wang; R. K. Janev

2009-01-01

140

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

141

Shot peening on the high-strength wrought magnesium alloy AZ80—Effect of peening media  

Microsoft Academic Search

Influence of shot peening media on fatigue performance of the high-strength wrought magnesium alloy AZ80 has been investigated at Almen intensities ranging from 0.04 to 0.4mmN. By the use of different peening media (including glass beads, Zirblast B30 and Ce-ZrO2 (ZrO2 beads stabilized by Ce)), the improvement of about 60–75% in fatigue strength was achieved at optimum conditions. Peening AZ80

P. Zhang; J. Lindemann; C. Leyens

2010-01-01

142

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

Microsoft Academic Search

This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for samples obtained from tank 241-AZ-102. The purpose of this sampling event is to obtain information about the characteristics of the contents of 241-AZ-102. Push mode core samples will be obtained from risers 15C and 24A to provide sufficient material for

1999-01-01

143

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

SciTech Connect

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

JENSEN, C.E.

1999-08-23

144

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

145

Microstructure and temperature monitoring during the hot rolling of AZ31  

Microsoft Academic Search

This study details the microstructural evolution during hot rolling of AZ31 alloy sheet using a pilot-scale rolling mill.\\u000a The aim is to understand the deformation mechanisms leading to grain refinement under industrial processing conditions and\\u000a to design and optimize the hot rolling schedule for AZ31 in order to produce sheet with a fine and homogeneous microstructure.\\u000a The study examined three

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

2009-01-01

146

Hot rolling characteristics of spray-formed AZ91 magnesium alloy  

Microsoft Academic Search

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

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

2007-01-01

147

Increasing elastic modulus, strength and CTE of AZ91 by reinforcing pure magnesium with elemental copper  

Microsoft Academic Search

Heat-treatable AZ91 and 3.9 vol.% copper particulate reinforced magnesium composite was synthesized using an innovative disintegrated melt deposition (DMD) technique followed by hot extrusion. Microstructural characterization of the composite material revealed retention and uniform distribution of reinforcement with defect free interface with the matrix. Physical properties characterization revealed improved dimensional stability of composite when compared to AZ91. Mechanical properties characterization

S. F Hassan; K. F Ho; M Gupta

2004-01-01

148

Electroless Ni–P deposition plus zinc phosphate coating on AZ91D magnesium alloy  

Microsoft Academic Search

An electroless Ni–P deposition process has been developed to treat the AZ91D magnesium alloy surfaces against corrosion. Magnesium alloy AZ91D was first phosphatized in a zinc phosphating bath containing molybdate. Then an electroless Ni–P deposition was carried out on the phosphate coating from a sulfate solution. The phases in the phosphate coatings were analyzed by XRD. Microstructures of phosphate coatings

J. S. Lian; G. Y. Li; L. Y. Niu; C. D. Gu; Z. H. Jiang; Q. Jiang

2006-01-01

149

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

SciTech Connect

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

STENKAMP, D.M.

2000-04-03

150

Evaluating the Plastic Anisotropy of AZ31 Using Microscopy Techniques  

NASA Astrophysics Data System (ADS)

The tensile deformation mechanism of a rolled AZ31 alloy at 50°C, 150°C, and 250°C was investigated by a combination of in situ tensile testing, electron backscatter diffraction analysis, and ex situ atomic force microscopy analysis. With increasing temperature, there was a significant difference in the activity of the various deformation modes, along with a decrease in the plastic strain ratio. Extension twinning was only observed at 50°C, while at higher temperatures, a combination of basal and prismatic slip accounted for a large percentage of the observed deformation activity. Prismatic slip was prevalent at all testing temperatures and exhibited increased activity with increasing temperature. The activity of pyramidal < c + a> slip increased from 50°C to 150°C and then decreased at 250°C. Ex situ atomic force microscopy measurements suggested that the contribution from grain boundary sliding to the overall strains increased with increasing temperature. Overall, the in situ experiments combined with atomic force microscopy suggested that grain boundary sliding contributed more to the reduction in plastic strain ratio with increasing temperature than nonbasal slip activity.

Chen, Z.; Boehlert, C. J.

2013-09-01

151

Fine particulate chemical composition and light extinction at Meadview, AZ  

SciTech Connect

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

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

2006-12-15

152

Oxide Film and Porosity Defects in Magnesium Alloy AZ91  

SciTech Connect

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

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

2009-01-01

153

-dimensional Symmetry Catalysts for A-Z Gas Loading Fusion  

NASA Astrophysics Data System (ADS)

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

Chubb, Talbot

2011-03-01

154

Analysis of anisotropy of extruded magnesium alloy AZ31 bar  

NASA Astrophysics Data System (ADS)

The large strain Elastic Visco-Plastic Self-Consistent (EVPSC) model, with the recently developed Twinning and De-Twinning (TDT) description, is applied to study the mechanical behavior of magnesium alloy AZ31 extrusion. Five different specimen orientations with tilt angles of ? of 0°, 22.5°, 45°, 67.5° and 90° between extrusion direction and longitudinal specimen axis are used to study the mechanical anisotropy under both uniaxial tension and compression. It is found that the uniform strain under tension is sensitive to the tilt angle and the maximum uniform strain is found at ? = 45°. The effect of pre-strain in uniaxial compression along the extrusion direction on subsequent uniaxial tension and compression along different directions with respect to the extrusion direction is also investigated. It is demonstrated that the influence of the twinning during pre-strain in compression and the detwinning in the subsequent uniaxial tension on the uniaxial tension response depends significantly on the tilt angle. By comparing the differences in the flow stress vs. orientation curves between the as-received and pre-strained samples, the effect of pre-straining on material anisotropy is investigated. It is found that the pre-compression lowers the uniform strain regardless of the tilt angle ?.

Qiao, H.; Wang, H.; Wu, P. D.

2013-05-01

155

City Lore  

NSDL National Science Digital Library

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

156

Influence of potassium pyrophosphate in electrolyte on coated layer of AZ91 Mg alloy formed by plasma electrolytic oxidation  

Microsoft Academic Search

The effect of potassium pyrophosphate in the electrolyte on plasma electrolytic oxidation (PEO) process for AZ91 Mg alloy was investigated. The morphologies and chemical compositions of the coating layer on the AZ91 Mg alloy were evaluated and corrosion resistance was also estimated by potentiodynamic polarization analysis. The coating layer on AZ91 Mg alloy coated from the Bath 2 containing 0.03

Jin-Young CHO; Duck-Young HWANG; Dong-Heon LEE; Bongyoung YOO; Dong-Hyuk SHIN

2009-01-01

157

Cold-rolling effect on damping capacity of high-temperature damping background for AZ80 magnesium alloy  

Microsoft Academic Search

Cold-rolling effect on damping capacity of AZ80 alloy at high-temperature damping background (HTDB) is investigated by dynamic mechanical analyzer tests. Damping capacity of the HTDB for AZ80 alloy can be increased significantly after severe cold rolling but that of the athermal damping background does not show conspicuous variation. The HTDB of AZ80 alloy exhibits a viscoelastic relaxation characteristic and its

S. H. Chang; S. K. Wu; W. L. Tsai; J. Y. Wang

2009-01-01

158

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

PubMed Central

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.

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

2012-01-01

159

City 2020+  

NASA Astrophysics Data System (ADS)

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

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

2010-09-01

160

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

161

Ghost City  

Microsoft Academic Search

Ghost City is a collection of poetry about Pittsburgh, Pennsylvania. It travels through the history, landscape, and family of the writer’s hometown. The poems take up themes of love, loss, food, hope, and family. The author seeks to emulate many characteristics of other poems such as the rich images and details of Elizabeth Bishop and the storytelling genius of Philip

Amanda J. Reynolds

2009-01-01

162

The Cities.  

ERIC Educational Resources Information Center

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

Nathan, Richard P.; Dommel, Paul R.

163

Impression Creep Behavior of a Cast AZ91 Magnesium Alloy  

NASA Astrophysics Data System (ADS)

The creep behavior of the cast AZ91 magnesium alloy was investigated by impression testing. The tests were carried out under constant punching stress in the range 100 to 650 MPa, corresponding to 0.007 ? ? imp/ G ? 0.044, at temperatures in the range 425 to 570 K. Assuming a power-law relationship between the impression velocity and stress, depending on the testing temperature, stress exponents of 4.2 to 6.0 were obtained. When the experimental creep rates were normalized to the grain size and effective diffusion coefficient, a stress exponent of approximately 5 was obtained, which is in complete agreement with stress exponents determined by the conventional creep testing of the same material reported in the literature. Calculation of the activation energy showed a slight decrease in the activation energy with increasing stress such that the creep-activation energy of 122.9 kJ/mol at ? imp/ G = 0.020 decreases to 94.0 kJ/mol at ? imp/ G = 0.040. Based on the obtained stress exponents and activation energy data, it is proposed that dislocation climb is the controlling creep mechanism. However, due to the decreasing trend of creep-activation energy with stress, it is suggested that two parallel mechanisms of lattice and pipe-diffusion-controlled dislocation climb are competing. To elucidate the contribution of each mechanism to the overall creep deformation, the creep rates were calculated based on the effective activation energy. This yielded a criterion that showed that, in the high-stress regimes, the experimental activation energies fall in the range in which the operative creep mechanism is dislocation climb controlled by dislocation pipe diffusion. In the low-stress regime, however, the lattice-diffusion dislocation climb is dominant.

Kabirian, F.; Mahmudi, R.

2009-01-01

164

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

2013-09-22

165

Formation of intermetallic compound coating on magnesium AZ91 cast alloy  

NASA Astrophysics Data System (ADS)

This study describes an intermetallic compound coating formed on AZ91 Mg cast alloy. The Al sputtered on AZ91 cast alloy reacted with substrate during a short period of heat treatment at 435°C, resulting in the formation of a continuous intermetallic compound layer. The short period treatment has the advantage of minimizing the negative effect on the microstructure of substrate and the mechanical properties, comparing with the reported diffusion coatings. DSC measurement and examination on the cross-section of Al sputtered samples show that local melting occurred along the Al/substrate interface at the temperature range between 430~435°C. The formation mechanism of intermetallic compound coating is proposed in terms of the local melting at Al/substrate interface. The salt water immersion test showed significant improvement in corrosion resistance of the intermetallic compound coated AZ91 cast alloy compared with the as-cast alloys.

Zhu, Tianping; Gao, Wei

2009-08-01

166

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

167

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

Microsoft Academic Search

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

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

2003-01-01

168

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

169

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

170

The human city beneath the social city  

Microsoft Academic Search

In the Atlanta Symposium (Hillier, 2001, 2003a) a theory of the social construction of the city was presented. In this paper it is proposed that underlying the various kinds of social city there is a deeper, more generic human city, which arises from the pervasive intervention of the human cognitive subject in the shaping and working of the city. This

Bill Hillier

171

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

2011-02-17

172

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

PubMed Central

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

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

2011-01-01

173

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

174

Corrosion morphology of AZ91D exposed in an atmospheric environment  

NASA Astrophysics Data System (ADS)

The focused ion beam technique was employed to investigate the atmospheric corrosion morphology of AZ91D. It was found that the ? matrix of the alloy was preferentially corroded in the areas adjacent to intermetallic phases. The most interesting finding was that the corrosion products in corrosion cavities were pelletlike, which has never been reported before.

Wan, Ye; Tan, Jun; Song, Guangling; Yan, Chuanwei

2006-07-01

175

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

National Technical Information Service (NTIS)

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...

A. F. Pardini D. R. Weier

2007-01-01

176

Evaluation of low cycle fatigue life in AZ31 magnesium alloy  

Microsoft Academic Search

Magnesium alloys are attracting engineers for their practical application to structural components. Here fatigue properties, which is essential for structural use, have been examined on extruded AZ31 bar under uniaxial cyclic loading by both strain and stress controlled conditions. Adding fatigue tests with mean stresses under stress controlling conditions, fatigue life evaluation method has been discussed along with the analysis

S. Hasegawa; Y. Tsuchida; H. Yano; M. Matsui

2007-01-01

177

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

Microsoft Academic Search

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

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

2009-01-01

178

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

179

Conduit changes and eruptive styles at Red Mountain cinder cone, AZ, USA  

Microsoft Academic Search

Red Mountain volcano is a Pleistocene (ca. 740 ky) cinder cone north of Flagstaff, AZ, in the northern Mio- Recent San Francisco volcanic field. Red Mountain erupted onto Permian sedimentary rocks with low topographic relief, likely covered in some places by older flows. The cone evolved through several stages that erupted and emplaced cinder, lava flow, agglutinate, and clastogenic lava.

N. R. Riggs; W. A. Duffield; K. V. Cashman; B. W. Zimmer

2006-01-01

180

Thermoelastic damping of the low density metals AZ91 and DISPAL  

Microsoft Academic Search

Light metals have high thermoelastic internal friction due to high coefficients of thermal expansion which has to be considered for various structural damping investigations. The thermoelastic effect of a powder metallurgically produced aluminium composite DISPAL™ and a magnesium casting alloy AZ91 (9 wt.% Al, 1 wt.% Zn) was investigated by measurements of the logarithmic decrement of free vibrations of bending

J. Göken; W. Riehemann

2002-01-01

181

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

SciTech Connect

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

Winkler, C.M.

1995-12-04

182

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

National Technical Information Service (NTIS)

This document presents the results of Operational Testing of the 241-AZ-101 Suspended Solids Profiler (SSP). Testing of the SSP was performed in accordance with OTP-260-005, 'Suspended Solids Profiler Operational Test Procedure.' The objective of the test...

D. M. Stenkamp

2000-01-01

183

Texture and microstructure changes in asymmetrically hot rolled AZ31 magnesium alloy sheets  

Microsoft Academic Search

Asymmetrically hot rolled AZ31 magnesium alloy sheets exhibited a texture gradient, where the intensity of {0002} basal textures decreased from the upper surface through the center to the lower surface. After subsequent annealing, the intensity of {0002} components was reduced significantly throughout the thickness and the grains were refined possibly by discontinuous recrystallization.

Su-Hyeon Kim; Bong-Sun You; Chang Dong Yim; Young-Myoung Seo

2005-01-01

184

Orientation effects on acoustic emission during tensile deformation of hot rolled magnesium alloy AZ31  

Microsoft Academic Search

Acoustic emission (AE) is observed during tensile testing of commercial AZ31 magnesium sheets in different temper conditions. Tests were conducted in rolling direction (RD) and transverse direction (TD), respectively. The results are discussed with respect to the crystallographic texture and the microstructure in terms of the orientation-dependent activation of different deformation mechanisms like dislocation glide and twinning.

J. Bohlen; F. Chmel??k; P. Dobro?; F. Kaiser; D. Letzig; P. Luká?; K. U. Kainer

2004-01-01

185

Effect of Cryogenic Treatment on the Microstructure and Mechanical Properties of AZ31 Magnesium Alloy  

Microsoft Academic Search

The effect of cryogenic treatment (77 K) on the microstructure and mechanical properties of magnesium and AZ31 magnesium alloy has been investigated in this article. The results show that tensile stress and the hardness of the samples treated in a cryogenic environment are higher than those of the untreated samples. The improvement of mechanical properties is highly dependent on the soaking

Yong Jiang; Ding Chen; Zhenhua Chen; Junwei Liu

2010-01-01

186

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

Microsoft Academic Search

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

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

2009-01-01

187

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

Federal Register 2010, 2011, 2012, 2013

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

2011-06-02

188

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

189

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

Federal Register 2010, 2011, 2012, 2013

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

2010-02-01

190

World energy book: an A--Z, atlas, and statistical source book. [with glossary  

Microsoft Academic Search

This book is a comprehensive reference guide to energy sources, energy-related terminology and technology, economics, and all the factors related to the search for, extraction of, production, and utilization of the major and alternative sources of energy. The book is divided into three main sections: an A--Z containing some 1500 terms and definitions, an Energy Resources Atlas, and a section

D. Crabbe; R. McBride

1978-01-01

191

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

192

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

NASA Astrophysics Data System (ADS)

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

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

2008-11-01

193

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

PubMed Central

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

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

2012-01-01

194

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

195

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

Federal Register 2010, 2011, 2012, 2013

...D AND E AIRSPACE AREAS; AIR TRAFFIC SERVICE...Class E airspace areas extending upward...or more above the surface of the earth. * * * * * AWP AZ...700 feet above the surface within a 6.5-mile...surface within an area bounded by a...

2013-03-26

196

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

Federal Register 2010, 2011, 2012, 2013

...D AND E AIRSPACE AREAS; AIR TRAFFIC SERVICE...Class E airspace areas extending upward...or more above the surface of the earth. * * * * * AWP AZ...700 feet above the surface within a 6.5-mile...surface within an area bounded by a...

2013-06-10

197

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

Federal Register 2010, 2011, 2012, 2013

...D AND E AIRSPACE AREAS; AIR TRAFFIC SERVICE...Class E airspace areas extending upward...or more above the surface of the earth. * * * * * AWP AZ...700 feet above the surface within a 6.5-mile...Class E airspace area. That airspace...

2011-01-20

198

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

Microsoft Academic Search

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

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

1993-01-01

199

Tensile properties and microstructure of AZ31B magnesium alloy sheet processed by repeated unidirectional bending  

Microsoft Academic Search

The mechanical properties of the AZ31B magnesium alloy sheet processed by repeated unidirectional bending (RUB) with a basal pole tilted in the rolling direction were systematically investigated at different temperatures. Compared with the as-received sheet exhibiting approximately the same average grain size, the fracture elongation increased while the proof stress decreased at room temperature. The initial texture had a significant

Guang-sheng HUANG; Hong-cheng LI; Bo SONG; Lei ZHANG

2010-01-01

200

Learning Cities as Healthy Green Cities: Building Sustainable Opportunity Cities  

ERIC Educational Resources Information Center

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

Kearns, Peter

2012-01-01

201

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

PubMed Central

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

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

2010-01-01

202

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

203

Key functional regions in the histone variant H2A.Z C-terminal docking domain.  

PubMed

The incorporation of histone variants into nucleosomes represents one way of altering the chromatin structure to accommodate diverse functions. Histone variant H2A.Z has specific roles in gene regulation, heterochromatin boundary formation, and genomic integrity. The precise features required for H2A.Z to function and specify an identity different from canonical H2A remain to be fully explored. Analysis of the C-terminal docking domain of H2A.Z in Saccharomyces cerevisiae using epistatic miniarray profile (E-MAP) uncovered nuanced requirements of the H2A.Z C-terminal region for cell growth when additional genes were compromised. Moreover, the H2A.Z(1-114) truncation, lacking the last 20 amino acids of the protein, did not support regular H2A.Z functions, such as resistance to genotoxic stress, restriction of heterochromatin in its native context, GAL1 gene activation, and chromatin anchoring. The corresponding region of H2A could fully rescue the strong defects caused by loss of this functionally essential region in the C terminus of H2A.Z. Despite the dramatic reduction in function, the H2A.Z(1-114) truncation still bound the H2A.Z deposition complex SWR1-C, the histone chaperone Chz1, and histone H2B. These data are consistent with a model in which retaining the variant in chromatin after its deposition by SWR1-C is a crucial determinant of its function. PMID:21791612

Wang, Alice Y; Aristizabal, Maria J; Ryan, Colm; Krogan, Nevan J; Kobor, Michael S

2011-07-26

204

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

PubMed Central

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

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

2012-01-01

205

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

206

Analysis of Human Histone H2AZ Deposition In Vivo Argues against Its Direct Role in Epigenetic Templating Mechanisms  

PubMed Central

Chromatin is considered to be a principal carrier of epigenetic information due to the ability of alternative chromatin states to persist through generations of cell divisions and to spread on DNA. Replacement histone variants are novel candidates for epigenetic marking of chromatin. We developed a novel approach to analyze the chromatin environment of nucleosomes containing a particular replacement histone. We applied it to human H2AZ, one of the most studied alternative histones. We find that neither H2AZ itself nor other features of the H2AZ-containing nucleosome spread to the neighboring nucleosomes in vivo, arguing against a role for H2AZ as a self-perpetuating epigenetic mark.

Viens, Antoine; Mechold, Undine; Brouillard, Franck; Gilbert, Cristele; Leclerc, Philippe; Ogryzko, Vasily

2006-01-01

207

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

SciTech Connect

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

WHITE, D.A.

1999-12-29

208

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

Microsoft Academic Search

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

P. Zhang; J. Lindemann; C. Leyens

2010-01-01

209

Fatigue and Tensile Behavior of Cast, Hot-Rolled, and Severely Plastically Deformed AZ31 Magnesium Alloy  

Microsoft Academic Search

The work focuses on experimental examination of the fatigue behavior of magnesium alloy AZ31 produced by three different procedures:\\u000a squeeze casting (SC), hot rolling (HR), and equal-channel angular pressing (ECAP). The microstructures produced were studied\\u000a by light and transmission electron microscopy (TEM). Squeeze-cast AZ31 had low porosity and coarse grains, while hot-rolled\\u000a material showed microstructure with grain size of 3

Z. Zúberová; L. Kunz; T. T. Lamark; Y. Estrin; M. Janecek

2007-01-01

210

High Cycle Fatigue Properties of Die-Cast Magnesium Alloy AZ91D with Addition of Different Concentrations of Cerium  

Microsoft Academic Search

The effect of addition of different concentrations of Ce on high-cycle fatigue behavior of die-cast magnesium alloy AZ91D was investigated. Mechanical fatigue tests were conducted at the stress ratio of R = 0.1, and fatigue strength was evaluated using up-and-down loading method. The results show that the grain size of AZ91D alloy is remarkably refined, and the amount of porosity

You Yang; Yongbing Liu; Shuying Qin; Yi Fang

2006-01-01

211

The use of microcapillary techniques to study the corrosion resistance of AZ91 magnesium alloy at the microscale  

Microsoft Academic Search

The AZ91 alloy is composed of Mg17(Al, Zn)12 precipitates, an eutectic phase around these precipitates, AlMn intermetallic particles and an ?-Mg solid solution (matrix). The corrosion behaviour of AZ91 was investigated at the microscale by means of the electrochemical microcell technique, which uses extremely small capillaries (diameters between 5 and 10?m). Experiments were conducted in 0.1M NaClO4 at 25°C. The

H. Krawiec; S. Stanek; V. Vignal; J. Lelito; J. S. Suchy

2011-01-01

212

Investigating the characteristics of AZ61 magnesium alloy on the hot and semi-solid compression test  

Microsoft Academic Search

The characteristics of magnesium AZ61 in semi-solid state have been investigated to understand the changes in its stress-strain\\u000a in the compression process, the effects on its strain under different processing temperatures, and the consequence of the\\u000a change of peak stress. First, the AZ61 magnesium alloy is heated to 660 C and sustained at that temperature for 5 min. Then\\u000a by natural cooling,

Jer-Liang Kuo; Sumio Sugiyama; Su-Hai Hsiang; Jun Yanagimoto

2006-01-01

213

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

214

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

215

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

PubMed

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

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

2013-02-28

216

An organic chromium-free conversion coating on AZ91D magnesium alloy  

NASA Astrophysics Data System (ADS)

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

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

2008-12-01

217

An Investigation to Double Hit Deformation Behavior of AZ31 Magnesium Alloy  

NASA Astrophysics Data System (ADS)

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.

2007-04-01

218

Electroless deposition of Ni W P coating on AZ91D magnesium alloy  

NASA Astrophysics Data System (ADS)

Ternary Ni W P alloy coating was deposited directly on AZ91D magnesium alloy by using an alkaline-citrate-based baths. Nickel sulfate and sodium tungstate were used as metal ion sources, respectively, and sodium hypophosphite was used as a reducing agent. The pH value of the electroless bath was tailored for magnesium alloy. The coating was characterized for its structure, morphology, microhardness and the corrosion properties. SEM observation showed the presence of dense and coarse nodules in the ternary coating. EDS analysis showed that the content of tungsten in the Ni W P alloy was 4.5 wt.%. Both the electrochemical analysis and the immersion test in 10% HCl solution revealed that the ternary Ni W P coating exhibited good corrosion resistance properties in protecting the AZ91D magnesium alloy.

Zhang, W. X.; Huang, N.; He, J. G.; Jiang, Z. H.; Jiang, Q.; Lian, J. S.

2007-03-01

219

Two very similar closely detached binary systems - AT and AZ Camelopardalis  

NASA Astrophysics Data System (ADS)

Photoelectric observations, in B and V, of AT and AZ Cam have been analyzed with the Wilson-Devinney method. For AT Cam, the eclipse at the primary is found to be total, even though the inclination is only 83 degrees. For AZ Cam, it is a partial occultation, with an inclination of 81 degrees. Both systems are found to be detached, but each of them is only separated by less than the radius of the large component. In both cases, the low mass components almost fill their Roche lobes. It is suggested that these systems are evolved close binary systems, and they have probably gone through the normal case A phase of binary evolution where, after mass loss, the loser is detached from its Roche surface and the gainer has evolved through the core hydrogen-burning phase.

Zhai, D. S.; Zhang, R. X.; Zhang, J. T.; Leung, K. C.

1984-12-01

220

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

221

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

PubMed

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

Ku, Manching; Jaffe, Jacob D; Koche, Richard P; Rheinbay, Esther; Endoh, Mitsuhiro; Koseki, Haruhiko; Carr, Steven A; Bernstein, Bradley E

2012-10-01

222

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

PubMed Central

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

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

2013-01-01

223

The City as Classroom.  

ERIC Educational Resources Information Center

The author gives a rationale for utilizing the city as a place to learn. The city has many problems and although logistics require that we conduct most education in the school building, the author argues for putting out best brains to the task of bringing the city to the classroom and to exploiting the city as a classroom when appropriate.…

Bailey, Stephen K.

224

Evolution of City Tourism  

Microsoft Academic Search

Since the ancient times, cities have attracted visitors in large numbers for a variety of reasons. In modern times, once again, large cities are competing among themselves for attracting tourists. Although, large cities have always attracted visitors but until recently, with the exception in cities like London, Paris, New York, and few others, tourist industry has not been perceived as

Niko Koncul

2005-01-01

225

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

Microsoft Academic Search

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

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

2011-01-01

226

Investigation of plasma electrolytic oxidation process on AZ91D magnesium alloy  

Microsoft Academic Search

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

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

2009-01-01

227

Corrosion performance of plasma electrolytic oxidized AZ31 magnesium alloy in silicate solutions with different additives  

Microsoft Academic Search

In this work, plasma electrolytic oxidation coatings were produced on AZ31 magnesium alloy. The electrolytes used were mainly composed of silicate, silicate with addition of phosphate or fluoride, respectively. Scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, X-ray diffraction (XRD), and potentiodynamic polarization tests were carried out to investigate the microstructure, element composition, phase composition and corrosion resistance of

Huan Chen; GuoHua Lv; GuLing Zhang; Hua Pang; XingQuan Wang; HeonJu Lee; SiZe Yang

2010-01-01

228

Improvements in the metallography of as-cast AZ91 alloy  

Microsoft Academic Search

Evaluation of the grain structure and grain size of cast magnesium–aluminum alloys is usually performed after grain-boundary-enhancing treatments which involve tedious heat treatment at high temperature. In this work, a rapid and simple etching method is described for metallographic preparation of AZ91 alloy, revealing grains without altering the as-cast dendritic microstructure and the presence of secondary phases. The etching reagent,

A Maltais; D Dubé; M Fiset; G Laroche; S Turgeon

2004-01-01

229

AzTEC 1.1 mm OBSERVATIONS OF THE MBM12 MOLECULAR CLOUD  

SciTech Connect

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

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

2012-02-10

230

AzTEC millimetre survey of the COSMOS field - I. Data reduction and source catalogue  

Microsoft Academic Search

We present a 1.1 mm wavelength imaging survey covering 0.3 deg2 in the COSMOS field. These data, obtained with the AzTEC continuum camera on the James Clerk Maxwell Telescope, were centred on a prominent large-scale structure overdensity which includes a rich X-ray cluster at z ~ 0.73. A total of 50 mm-galaxy candidates, with a significance ranging from 3.5 to

K. S. Scott; J. E. Austermann; T. A. Perera; G. W. Wilson; I. Aretxaga; J. J. Bock; D. H. Hughes; Y. Kang; S. Kim; P. D. Mauskopf; D. B. Sanders; N. Scoville; M. S. Yun

2008-01-01

231

Corrosion of AZ91D magnesium alloy with a chemical conversion coating and electroless nickel layer  

Microsoft Academic Search

A chemical conversion treatment and an electroless nickel plating were applied to AZ91D alloy to improve its corrosion resistance. By conversion treatment in alkaline stannate solution, the corrosion resistance of the alloy was improved to some extent as verified by immersion test and potentiodynamic polarization test in 3.5 wt.% NaCl solution at pH 7.0. X-ray diffraction patterns of the stannate

Hongwei Huo; Ying Li; Fuhui Wang

2004-01-01

232

Effect of stress state on the high temperature workability of AZ31 Mg alloy  

Microsoft Academic Search

The influence of stress state on the high temperature workability of rolled AZ31 Mg alloy was investigated on the basis of\\u000a a processing map. To construct the processing map, high temperature compression tests were carried out on samples oriented\\u000a parallel to the rolling direction at various temperatures (25 °C?450 °C) and strain rates (10?3 s?1?5s?1), and then the results were

Byoung Ho Lee; Sun Mi Kim; Mohamed El Mehtedi; Enrico Evangelista; Chong Soo Lee

2010-01-01

233

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

Microsoft Academic Search

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

Waled M. Elthalabawy; Tahir I. Khan

2011-01-01

234

Formation mechanism of an aluminium-based chemical conversion coating on AZ91D magnesium alloy  

Microsoft Academic Search

An environmentally clean aluminium-based conversion coating on AZ91D magnesium alloy was studied in aluminium nitrate solutions.\\u000a The morphology, composition, structure, and formation mechanism of the coating were investigated in detail using scanning\\u000a electron microscopy\\/energy dispersion spectrometry, X-ray diffraction, transmission electron microscopy, and electrochemical\\u000a corrosion tests. The results show that the conversion coating is composed of magnesium, aluminium, and oxygen, and

Wei-Ping Li; Xi-Mei Wang; Li-Qun Zhu; Wen Li

2010-01-01

235

Warm deformation behavior of hot-rolled AZ31 Mg alloy  

Microsoft Academic Search

Uniaxial tensile test was employed to evaluate the warm deformation properties of hot-rolled AZ31 Mg alloy at a temperature range of 50–200°C and a strain rate range of 1.4×10?3s?1–1.4×10?1s?1. The dynamic recrystallization (DRX) and twinning during the warm deformation were observed by optical microscopy (OM) and transmission electronic microscopy (TEM). It is shown that twinning characterized by a compound mode

D. L. Yin; K. F. Zhang; G. F. Wang; W. B. Han

2005-01-01

236

Tensile properties of hot rolled AZ31 Mg alloy sheets at elevated temperatures  

Microsoft Academic Search

Mechanical properties of commercial wrought AZ31B magnesium alloy sheets were investigated by tensile tests at various temperatures between room temperature and 400°C at a strain rate of 1.3×10?4s?1. The yield stress and the maximum stress decrease with increasing temperature. The ductility increases very rapidly with increasing temperature. The results are explained by the dislocation glide in the basal and non-basal

A. Jäger; P. Luká?; V. Gärtnerová; J. Bohlen; K. U. Kainer

2004-01-01

237

Texture evolution during large-strain hot rolling of the Mg AZ61 alloy  

Microsoft Academic Search

Grain refinement in a Mg-based AZ61 alloy of initially coarse, recrystallized microstructure was successfully achieved by thermomechanical processing (TMP) consisting of two to three hot-rolling steps with large reductions per pass. Reductions as large as 85% (equivalent to a true strain of ?1) were achieved without surface cracking. The underlying microscopic mechanisms operative during the TMP that allowed this hcp

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

2003-01-01

238

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

239

Microstructure and texture evolution of AZ31 magnesium alloy during rolling  

Microsoft Academic Search

The production of magnesium alloy sheets normally involves several processing stages including hot rolling, cold rolling and intermediate annealing. The microstructure and texture evolution of AZ31 magnesium alloy sheets in different processing states were investigated by optical microscopy and X-ray diffraction technique. It is found that the microstructure of hot-rolled sheets is dominated by recrystallized equiaxed grains, while that of

Guang-jie HUANG; Qing LIU; Ling-yun WANG; Ren-long XIN; Xing-pin CHEN; Fu-sheng PAN

2008-01-01

240

The semi-solid tensile deformation behavior of wrought AZ31 magnesium alloy  

Microsoft Academic Search

The semi-solid tensile deformation behavior of wrought AZ31 magnesium alloy has been studied through applying a set of low strain rate (0.001s?1) hot tension tests at temperature range of 300–500°C. The results indicated a ductility drop at ?450±25°C. This was attributed to the occurrence of eutectic reaction (L??+?) and the partial melting of intermetallic ? phase. The ductility was started

H. R. Abedi; A. Zarei-Hanzaki; S. M. Fatemi-Varzaneh; Ali A. Roostaei

2010-01-01

241

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

Microsoft Academic Search

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

Qing Li; Xiankang Zhong; Junying Hu; Wei Kang

2008-01-01

242

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

SciTech Connect

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

Morrey, E.V.

1996-03-01

243

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

Microsoft Academic Search

This work evaluates the first-order effect of land-use\\/land-cover change (LULCC) on the summer climate of one of the nation's most rapidly expanding metropolitan complexes, the Greater Phoenix, AZ, region. High-resolution—2-km grid spacing—Regional Atmospheric Modeling System (RAMS) simulations of three “wet” and three “dry” summers were carried out for two different land-cover reconstructions for the region: a circa 1992 representation based

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

2008-01-01

244

The influence of thermomechanical treatment on the complex modulus of Mg alloy AZ31  

Microsoft Academic Search

Dynamic modulus analyses were performed on Mg alloy AZ31 following thermomechanical treatments to enable investigation of\\u000a the influence of microstructural features created by plastic deformation on the elastic and the anelastic behavior of this\\u000a alloy as quantified by variations in the complex elastic modulus (E* = E? + iE?) with temperature. The real component or storage modulus (E?) determined for

A. Munitz; R. E. Ricker; D. J. Pitchure; G. Kimmel

2005-01-01

245

Electroless deposition of Ni–W–P coating on AZ91D magnesium alloy  

Microsoft Academic Search

Ternary Ni–W–P alloy coating was deposited directly on AZ91D magnesium alloy by using an alkaline-citrate-based baths. Nickel sulfate and sodium tungstate were used as metal ion sources, respectively, and sodium hypophosphite was used as a reducing agent. The pH value of the electroless bath was tailored for magnesium alloy. The coating was characterized for its structure, morphology, microhardness and the

W. X. Zhang; N. Huang; J. G. He; Z. H. Jiang; Q. Jiang; J. S. Lian

2007-01-01

246

Characterization of Al–Mn particles in AZ91D investment castings  

Microsoft Academic Search

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

S. Lun Sin; D. Dubé; R. Tremblay

2007-01-01

247

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

248

PVD Coating of Mg–AZ31 by Thin Layer of Al and Al–Si  

Microsoft Academic Search

Although magnesium alloys have the advantage of high specific strength, they have poor atmospheric corrosion resistance. An\\u000a important method of improving the corrosion resistance is by applying a coating layer. In this work, the physical vapor deposition\\u000a (PVD) technique is used for coating a magnesium (Mg) AZ31 sheet substrate with a thin layer of high purity aluminum (Al) and\\u000a Al–12.6%

Mohamed A. Taha; Nahed A. El-Mahallawy; Rawia M. Hammouda; Sherif I. Nassef

2010-01-01

249

AzTEC 1.1 mm Observations of the MBM12 Molecular Cloud  

NASA Astrophysics Data System (ADS)

We present 1.1 mm observations of the dust continuum emission from the MBM12 high-latitude molecular cloud observed with the Astronomical Thermal Emission Camera (AzTEC) mounted on the James Clerk Maxwell Telescope on Mauna Kea, Hawaii. We surveyed 6.34 deg2 centered on MBM12, making this the largest area that has ever been surveyed in this region with submillimeter and millimeter telescopes. Eight secure individual sources were detected with a signal-to-noise ratio of over 4.4. These eight AzTEC sources can be considered to be real astronomical objects compared to the other candidates based on calculations of the false detection rate. The distribution of the detected 1.1 mm sources or compact 1.1 mm peaks is spatially anti-correlated with that of the 100 ?m emission and the 12CO emission. We detected the 1.1 mm dust continuum emitting sources associated with two classical T Tauri stars, LkH?262 and LkH?264. Observations of spectral energy distributions (SEDs) indicate that LkH?262 is likely to be Class II (pre-main-sequence star), but there are also indications that it could be a late Class I (protostar). A flared disk and a bipolar cavity in the models of Class I sources lead to more complicated SEDs. From the present AzTEC observations of the MBM12 region, it appears that other sources detected with AzTEC are likely to be extragalactic and located behind MBM12. Some of these have radio counterparts and their star formation rates are derived from a fit of the SEDs to the photometric evolution of galaxies in which the effects of a dusty interstellar medium have been included.

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

2012-02-01

250

Investigation of the gas-jet ejector in KamAZ trucks  

Microsoft Academic Search

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

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

1984-01-01

251

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

252

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

253

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

254

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

255

Comparative analysis of H2A.Z nucleosome organization in the human and yeast genomes  

PubMed Central

Eukaryotic DNA is wrapped around a histone protein core to constitute the fundamental repeating units of chromatin, the nucleosomes. The affinity of the histone core for DNA depends on the nucleotide sequence; however, it is unclear to what extent DNA sequence determines nucleosome positioning in vivo, and if the same rules of sequence-directed positioning apply to genomes of varying complexity. Using the data generated by high-throughput DNA sequencing combined with chromatin immunoprecipitation, we have identified positions of nucleosomes containing the H2A.Z histone variant and histone H3 trimethylated at lysine 4 in human CD4+ T-cells. We find that the 10-bp periodicity observed in nucleosomal sequences in yeast and other organisms is not pronounced in human nucleosomal sequences. This result was confirmed for a broader set of mononucleosomal fragments that were not selected for any specific histone variant or modification. We also find that human H2A.Z nucleosomes protect only ?120 bp of DNA from MNase digestion and exhibit specific sequence preferences, suggesting a novel mechanism of nucleosome organization for the H2A.Z variant.

Tolstorukov, Michael Y.; Kharchenko, Peter V.; Goldman, Joseph A.; Kingston, Robert E.; Park, Peter J.

2009-01-01

256

Effects of Rare Earth Element Additions on the Impression Creep Behavior of AZ91 Magnesium Alloy  

NASA Astrophysics Data System (ADS)

The effects of 1, 2, and 3 wt pct rare earth (RE) element additions on the microstructure and creep behavior of cast AZ91 Mg alloy were investigated by impression tests. The tests were carried out under constant punching stress in the range 200 to 650 MPa at temperatures in the range 425 to 525 K. Analysis of the data showed that for all loads and temperatures, the AZ91-2RE alloy had the lowest creep rates and, thus, the highest creep resistance among all materials tested. This is attributed to the formation of Al11RE3 with a branched morphology, reduction in the volume fraction of the eutectic ?-Mg17Al12 phase, and solid solution hardening effects of Al in the Mg matrix. The stress exponents and activation energies were the same for all alloy systems studied, 5.3 to 6.5 and 90 to 120 kJ mol-1, respectively, with the exception that the activation energy for the AZ91-3RE system was 102 to 126 kJ mol-1. An observed decreasing trend of creep-activation energy with stress suggests that two parallel mechanisms of lattice and pipe diffusion-controlled dislocation climb are competing. Dislocation climb controlled by dislocation pipe diffusion is controlling at high stresses, whereas climb of edge dislocations is the controlling mechanism at low stresses.

Kabirian, F.; Mahmudi, R.

2009-09-01

257

Evaluation of corrosion resistance of casting magnesium alloy AZ31 in NaCl solutions  

NASA Astrophysics Data System (ADS)

The results of tests of corrosion resistance of casting magnesium alloy AZ31 in NaCl solutions of 0,01÷2 M concentration have been presented. Electrochemical measurements were carried out with application of VoltaLab®PGP201 system by Radiometer. On the ground of registered polarisation curves, typical features characterising alloy resistance to electrochemical corrosion, i.e. corrosion potential, polarisation resistance, corrosion current density and corrosion rate, were determined. Electrochemical impedance spectroscopy was applied for evaluation of phenomena that occurred on the surface of the tested alloy. Resistance to corrosion was tested by means of immersion method for 1÷5 days. By means of scanning electron microscope with field emission FE SEM S-4200 Hitachi in cooperation with spectrometer EDS Voyager 3500 Noran Instruments, quantitative and qualitative analysis of chemical composition in micro-zones was made. The study also presents the results of measurements of geometrical features of AZ31 alloy surface after corrosion tests. The results of the tests show undoubtedly deterioration of corrosion properties of magnesium alloy AZ31 together with the increase in molar concentration of NaCl solution.

Przondziono, J.; Walke, W.; Szala, J.; Hadasik, E.; Wieczorek, J.

2011-05-01

258

A magyar marhahús versenyesélyei az EU-ban  

Microsoft Academic Search

A tanulmány a magyarországi vágásra szánt, élőszarvasmarha-külkereskedelem versenyképességét, komparatív előnyeit és hátrányait vizsgálja az 1999–2010 közötti időszakban. A marhahús jelentős része elsősorban exportra kerül. Vizsgálva ennek versenyképességét megállapítható, hogy jelenleg komparatív hátránya van az EU27-en belüli marhahúspiacon. A mutatók tendenciáját tekintve a hátrány mértéke évről évre csökkenő. Az RSCA-átlag mutatója a folyamatos emelkedést követően 2008-ban pozitív volt. A külkereskedelmi mérleg

Kornelia Meszaros; Daniel Beres

2011-01-01

259

Doubly Patternable Planarizing Lithography with AZ5214E Resist for Three Dimensional Processing  

NASA Astrophysics Data System (ADS)

In this paper we introduce a lithography method for AZ5214E resist that adds three dimensionality into the standard optical lithography. With the method we are able to define, e.g., shallow air bridges and metal cross-overs in a single lithography step thus simplifying the device prosessing considerably. The main aim of the original process is towards metallization of nano- and micrometer scale vertical structures with device height of about 1 micrometers or less. Our method for doubly patternable planarizing lithography with AZ5214E resist relies on utilizing optically sensitive AZ5214E in both planarizing layer and top layer in a way that the planarizing layer is patternable separately. The planarizing layer is patterned in the image reversal mode of the resist, and the associated lithography steps are integrated with top layer processing such that the overall lithography is kept simple and reproducible. The typical thickness of the planarizing layer is 1,4µm, which forms the upper limit for the vertical height of structures defined with the planarizing layer. We demonstrate the applicability of the doubly patternable lithography with an implementation to our heterojunction bipolar transistor process. The process included air bridged metal cross overs and air bridges for smooth entrance into the transistor active area. Finally, the applicability of our process towards small 3D structures is briefly discussed.

Hovinen, A.

260

AZ AGRÃR- ÉS VIDÉKFEJLESZTÉS FENNTARTHATÓ RENDSZERE  

Microsoft Academic Search

A témakörben végzett eddigi vizsgálódásaink alapján egyre jobban kirajzolha-tó, hogy a globalizálódó világ ellentmondásaiból való kilábalás a fenntarthatóság-tól, a kreativitástól, az alternatív erőforrások térnyerésétől és az emberek összefo-gásától remélhető. Ez még inkább igaz a rendszerváltozás átalakulási, átmeneti gondjainak következményeivel vesződő hazai agrárgazdaságra és vidékre. A fenntarthatóság és a vidékfejlesztés kibontakozása az Európai Unióban egymástól függetlenül párhuzamosan halad, s nem sokkal

Laszlo Csete

2005-01-01

261

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.

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

262

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

PubMed

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

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

2013-08-22

263

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

264

H2A.Z Is Required for Global Chromatin Integrity and for Recruitment of RNA Polymerase II under Specific Conditions  

Microsoft Academic Search

Evolutionarily conserved variant histone H2A.Z has been recently shown to regulate gene transcription in Saccharomyces cerevisiae. Here we show that loss of H2A.Z in this organism negatively affects the induction of GAL genes. Importantly, fusion of the H2A.Z C-terminal region to S phase H2A without its corresponding C-terminal region can mediate the variant histone's specialized function in GAL1-10 gene induction,

MARYSE ADAM; FRANCOIS ROBERT; MARC LAROCHELLE; L. Gaudreau

2001-01-01

265

Community Based Outpatient Clinic Reviews Spring City and Springfield, PA. Sarasota and Sebring, FL., Paragould, AR., and Salem, MO. Cottonwood and Lake Havasu City, AZ.  

National Technical Information Service (NTIS)

The VA Office of Inspector General (OIG) is undertaking a systematic review of the Veterans Health Administrations (VHAs) community-based outpatient clinics (CBOCs) to assess whether CBOCs are operated in a manner that provides veterans with consistent, s...

2011-01-01

266

What Is Clean Cities?  

SciTech Connect

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

Not Available

2007-08-01

267

Soda Bottle City.  

ERIC Educational Resources Information Center

|Introduces the Soda Bottle City project which meets Content Standard C of the National Science Education Standards. Involves design and construction of the city with appropriate energy sources. (YDS)|

Gampel, Manette

2001-01-01

268

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

269

Call for observations of the AZ Cas eclipse and periastron passage of 2012-2014  

NASA Astrophysics Data System (ADS)

AZ Cas is a unique long period eclipsing binary (P_orb approx. 9.3 yr). It shows long eclipses lasting for more than 4 months which are very deep in the blue wavebands. The spatial configuration of highly eccentric orbit, the huge diameter of the supergiant and its extended envelope causes that the eclipses occurring close to the periastron passage are accompanied by ellipsoidal, scattering and absorption effects. The next eclipse in the optical BVRI region will begin at the end of 2012. We appeal for intensive photometric and spectroscopic observations during 2012-2014 in the framework of an international campaign.

Galan, C.; Tomov, T.; Mikolajewski, M.; Swierczynski, E.; Wychudzki, P.; Bondar, A.; Kolev, D.; Brozek, T.; Drozd, K.; Ilkiewicz, K.

2012-06-01

270

Influences of Welding Processes on Microstructure, Hardness, and Tensile Properties of AZ31B Magnesium Alloy  

NASA Astrophysics Data System (ADS)

This article reports the influences of welding processes such as gas tungsten arc welding (GTAW), friction stir welding (FSW), and laser beam welding (LBW) on tensile properties of AZ31B magnesium alloy. The lowest hardness distribution profile (LHDP) is constructed across the weld section to identify the fracture path. From this investigation, it is found that LBW joints exhibited superior tensile properties compared to GTAW and FSW joints and this is mainly due to the formation of very fine grains in the fusion zone and absence of heat-affected zone (HAZ).

Padmanaban, G.; Balasubramanian, V.; Sarin Sundar, J. K.

2010-03-01

271

Growth of zinc phosphate coatings on AZ91D magnesium alloy  

Microsoft Academic Search

Zinc phosphate coating was formed on AZ91D magnesium alloy through a phosphating bath where H3PO4, ZnO, Zn(NO3)2 and NaF were applied. Chlorate (NaClO3) was used as an accelerator of phosphatization to replace nitrite. The coating compositions were hopeite (Zn3(PO4)2·4H2O) and Zn. The growth process of the phosphate film on the magnesium alloy substrate was investigated by SEM observation and XRD

G. Y. Li; J. S. Lian; L. Y. Niu; Z. H. Jiang; Q. Jiang

2006-01-01

272

A study and application of zinc phosphate coating on AZ91D magnesium alloy  

Microsoft Academic Search

A technology for obtaining the zinc phosphate coating on an AZ91D magnesium alloy was investigated. The main ingredients in the phosphating bath were H3PO4, ZnO and NaF. This coating has typical phosphate microstructure, and the compositions in this coating analyzed by XRD are Zn3(PO4)2·4H2O, Zn, AlPO4 and MgZn2(PO4)2. Scanning electron microscopy (SEM) has shown that very fine zinc particles surrounded

L. Y. Niu; Z. H. Jiang; G. Y. Li; C. D. Gu; J. S. Lian

2006-01-01

273

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

274

Corrosion behaviors in physiological solution of cerium conversion coatings on AZ31 magnesium alloy  

NASA Astrophysics Data System (ADS)

We obtained the compact cerium conversion coating with tiny and thick cracks on biomaterial AZ31 magnesium alloys. The coating is made of CeO 2 , CeO, Ce 2 O 3 , MgO, Mg(OH) 2 and Al 2 O 3 . The conversion coating can slow down the degradation of magnesium alloys immersed in Hank's solution for 24 h. The degradation elements were the essential element and a platform for forming a natural bone. Cerium conversion coating had better corrosion resistance than bare sample via electrochemical tests in Hank's solution.

Cui, Xiufang; Yang, Yuyun; Liu, Erbao; Jin, Guo; Zhong, Jinggao; Li, Qingfen

2011-09-01

275

Einstein in the City  

NASA Astrophysics Data System (ADS)

On his first trip to the United States in April 1921, Albert Einstein visited The City College of New York before he proceeded to Columbia and Princeton Universities. As a result, Einstein gave his very first scientific speech in the United States at The City College, known simply and cordially to New Yorkers as ``the City.'' That visit, however, is now rarely known. This paper will investigate why Einstein came to the City, what he spoke there, and the significance and consequences of his visit. In particular, the paper will discuss Einstein's associations with Reinhard Wetzel, a physicist, and Morris R. Cohen, a philosopher, at the City.

Hu, Danian

2007-04-01

276

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.

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

2011-01-01

277

AZ 242, a novel PPAR ? \\/ ? agonist with beneficial effects on insulin resistance and carbohydrate and lipid metabolism in ob\\/ob mice and obese Zucker rats  

Microsoft Academic Search

Abnormalities in fatty acid (FA) metabolism un- derlie the development of insulin resistance and alterations in glucose metabolism, features characteristic of the meta- bolic syndrome and type 2 diabetes that can result in an increased risk of cardiovascular disease. We present phar- macodynamic effects of AZ 242, a novel peroxisome pro- liferator activated receptor (PPAR) ? \\/ ? agonist. AZ

Bengt Ljung; Krister Bamberg; Björn Dahllöf; Ann Kjellstedt; Nicholas D. Oakes; Jörgen Östling; Lennart Svensson; Germán Camejo

278

77 FR 19610 - Marc Knapp, Inmate #-06450-015, FCI Safford, P.O. Box 9000, Safford, AZ 85548; Order Denying...  

Federal Register 2010, 2011, 2012, 2013

...Security Marc Knapp, Inmate --06450-015, FCI Safford, P.O. Box 9000, Safford, AZ 85548; Order Denying Export Privileges...known address at: Inmate --06450-015, FCI Safford, P.O. Box 9000, Safford, AZ 85548, and when acting for or on...

2012-04-02

279

In vitro binding characteristics of [3H]AZ11637326, a novel alpha7-selective neuronal nicotinic receptor agonist radioligand.  

PubMed

AZ11637326 (5'-(2-fluoro[3,4,5(-3)H3]phenyl)-spiro[1-azabicyclo [2.2.2]octane-3,2'(3'H)-furo[2,3-b]pyridine) is a potent partial agonist at the human alpha7 neuronal nicotinic receptor with sub-nanomolar affinity for the human and rat alpha7 [(125)I]alpha-bungarotoxin binding sites. In a search for novel agonist radioligands and imaging ligands for the alpha7 nicotinic receptor, [(3)H]AZ11637326 was synthesized and its in vitro membrane binding properties were characterized. [(3)H]AZ11637326 bound to halpha7-HEK membranes with high specificity (>95%), high affinity (230 pM) and a B(max) of 460 fmol/mg. The rank order of affinity of nicotinic standards determined with [(3)H]AZ11637326 strongly correlated with those determined using the classical alpha7 antagonist [(125)I]alpha-bungarotoxin, indicating that [(3)H]AZ11637326 bound to halpha7-HEK membranes with an alpha7 nicotinic-like pharmacology. The K(i) values for the standards were on average 2.3-fold lower affinity than determined using the prototypical alpha7 nicotinic antagonist [(125)I]alpha-bungarotoxin. Because [(3)H]AZ11637326 specific binding is rapid and reversible, the K(i) values determined using this ligand are more accurate estimates of affinity than those determined using the kinetically sluggish [(125)I]alpha-bungarotoxin. [(3)H]AZ11637326 also bound to a high affinity (510 pM), nicotine-sensitive site on rat hippocampal membranes with an average B(max) of 55 fmol/mg. With rat hippocampal membranes, the nicotine-sensitive fraction of total binding was sub-optimal for a radioligand (~50%), yet the potencies and rank order of the K(i) values for standards were consistent with an alpha7 nicotinic pharmacology. Overall, these studies indicate that [(3)H]AZ11637326 is a useful new in vitro probe of the alpha7 nicotinic receptor agonist site and support its potential utility for in vivo receptor occupancy studies. PMID:20674564

Gordon, John C; Phillips, Eifion; Gurley, David A; Heys, J Richard; Lazor, Lois Ann; Barthlow, Herbert G; Mallamaci, Mike A; Keith, Rich A

2010-07-30

280

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.

281

Identification of an advanced constitutive model of Magnesium alloy AZ31B  

NASA Astrophysics Data System (ADS)

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

Liu, Z. G.; Massoni, E.

2011-05-01

282

Identification of an advanced constitutive model of Magnesium alloy AZ31B  

SciTech Connect

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

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

2011-05-04

283

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

USGS Publications Warehouse

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

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

2010-01-01

284

Microstructure control during twin roll casting of an AZ31 magnesium alloy  

NASA Astrophysics Data System (ADS)

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

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

2012-01-01

285

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

286

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

287

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

NASA Astrophysics Data System (ADS)

A commercial AZ31 magnesium alloy sheet has been tested under proportional biaxial tensile loading using cruciform specimens. In order to quantitatively determine the elastic-plastic deformation behavior of the test material, the contours of plastic work and the directions of plastic strain rates were measured over a range of equivalent plastic strain, 0.001 <=?0p<=0.008. The measured work contours and the directions of plastic strain rates have been compared with those predicted using the von Mises, Hill'48 and the Yld2000-2d yield functions. The validity of these yield functions is discussed from viewpoints of the yield surface shape and normality flow rule in the first quadrant of the stress space. The r-value of AZ31 was found to increase with plastic strain. The effect of the changes in r-value on the shape of the calculated yield locus has been discussed. Furthermore, biaxial unloading tests following biaxial loading were carried out for several stress ratios. The nonlinearity of the stress-strain curves during uniaxial and biaxial unloading was measured and quantitatively evaluated.

Andar, Mohammad Omar; Steglich, Dirk; Kuwabara, Toshihiko

2011-01-01

288

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

289

Studies of the AZ91 magnesium alloy / SiO2-coated carbon fibres composite microstructure  

NASA Astrophysics Data System (ADS)

The microstructure of magnesium matrix composite reinforced with SiO2nano-layer coated carbon fibres, deposited by sol-gel method was characterized. The composite was obtained by infiltration method and the effect of SiO2 on the composite microstructure was analyzed by scanning electron microscopy combined with energy-dispersive X-ray spectroscopy (SEM+EDS) and transmission electron microscopy combined with energy-dispersive X-ray spectroscopy (TEM+EDS) methods. Good wettability of fibres by the magnesium alloy AZ91 (Al 9 wt%, Zn 0.3 wt%) was confirmed since fibres were closely surrounded with alloy and pulling-out effect was not visible. The interface region was evidently with aluminium enriched. Near carbon fibre surface a regular layer of SiOX oxide enriched with Al was detected by high angle annular dark field image (HAADF) combined with energy-dispersive X-ray spectroscopy (EDS). The plate or needle shaped very fine particles of Al12Mg17 were identified near the AZ91 matrix zone by bright field (BF) and selected area electron diffraction (SADP).

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

2010-02-01

290

Fatigue of AZ91E-T6 cast magnesium alloy  

SciTech Connect

The purpose of this research was to obtain room temperature fatigue behavior of AZ91E-T6 cast magnesium alloy and to determine if commonly used models that depict fatigues behavior are applicable to this cast alloy. Axial strain-controlled fatigue behavior using cylindrical specimens were employed to determine low cycle fatigue behavior. The conventional log-log total strain low cycle fatigue model properly represented the R = [minus]1 axial fatigue data. Significant means stress relaxation occurred for all R = 0 and [minus]2 axial fatigue tests. However, for the smaller strain amplitude tests with R = 0, sufficient mean stresses were retained such that fatigue life was reduced. The mean strains/stresses had little influence on the cyclic stress-strain curve which exhibited cyclic strain hardening. Mean stress effects were analyzed using the Morrow, SWT and Lorenzo-Laird models and similar, but oftentimes nonconservative, calculations resulting. Region 1 and 2 fatigue crack growth behavior was determined using C(T) specimens with load ratios R = P[sub min]/P[sub max] = 0.05 and 0.5. The commonly used low cycle fatigue and fatigue crack growth models appear to reasonably represent most of the results with this AZ91E-T6 cast magnesium alloy.

Goodenberger, D.L.; Stephens, R.I. (Univ. of Iowa, Iowa City, IA (United States). Mechanical Engineering Dept.)

1993-10-01

291

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 µm 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 µm to make it a potent inoculant.

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

2012-02-01

292

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

SciTech Connect

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

Manthei, M.E.

1995-07-01

293

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

294

BEHAVIOUR PREFERENCES AND CITIES  

Microsoft Academic Search

Abstract The resurgence of big, old cities and their regions took urban theory by surprise. A great deficiency of much urban theory is that it is static, partial, and backward-looking. As such, it has few tools to understand large-scale, medium-term change in complex systems such as cities. Explainingsuch changes requires realistic assumptionsabout the behaviours that make cities. Did resurgence occur

Urban Resurgence; Michael Storper; Michael Manville

295

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

296

Abnormal distribution of microhardness in tungsten inert gas arc butt-welded AZ61 magnesium alloy plates  

Microsoft Academic Search

In this study, the effects of heat input on the distribution of microhardness of tungsten inert gas (TIG) arc welded hot-extruded AZ61 magnesium alloy joints were investigated. The results show that with an increase of heat input, the distributions of microhardness at the top and bottom of the welded joints are different because they are determined by both the effect

Nan Xu; Jun Shen; Weidong Xie; Linzhi Wang; Dan Wang; Dong Min

2010-01-01

297

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

Microsoft Academic Search

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

Hongping Duan; Chuanwei Yan; Fuhui Wang

2007-01-01

298

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

NASA Astrophysics Data System (ADS)

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

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

2012-03-01

299

Effect of sheet thickness on the microstructural evolution of an Mg AZ61 alloy during large strain hot rolling  

Microsoft Academic Search

Using texture analysis and optical microscopy it has been found that, due to the large anisotropy of the hcp lattice, the deformation mechanism predominant during large strain hot rolling of an AZ61 Mg alloy changes from dislocation slip and rotational recrystallization (RRX) to twinning as the sheet thickness is reduced.

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

2004-01-01

300

Histone H2A.Z inheritance during the cell cycle and its impact on promoter organization and dynamics.  

PubMed

Although it has been clearly established that well-positioned histone H2A.Z-containing nucleosomes flank the nucleosome-depleted region (NDR) at the transcriptional start site (TSS) of active mammalian genes, how this chromatin-based information is transmitted through the cell cycle is unknown. We show here that in mouse trophoblast stem cells, the amount of histone H2A.Z at promoters decreased during S phase, coinciding with homotypic (H2A.Z-H2A.Z) nucleosomes flanking the TSS becoming heterotypic (H2A.Z-H2A). To our surprise these nucleosomes remained heterotypic at M phase. At the TSS, we identified an unstable heterotypic histone H2A.Z-containing nucleosome in G1 phase that was lost after DNA replication. These dynamic changes at the TSS mirror a global expansion of the NDR at S and M phases, which, unexpectedly, is unrelated to transcriptional activity. Coincident with the loss of histone H2A.Z at promoters, histone H2A.Z is targeted to the centromere when mitosis begins. PMID:23085713

Nekrasov, Maxim; Amrichova, Jana; Parker, Brian J; Soboleva, Tatiana A; Jack, Cameron; Williams, Rohan; Huttley, Gavin A; Tremethick, David J

2012-10-21

301

ESEM observation of the process of hydrogen generation around the micro-droplets forming on AZ91 magnesium alloy  

Microsoft Academic Search

The process of hydrogen generation around micro-droplets on as-cast AZ91 magnesium alloy in an atmosphere of water vapor was in situ observed using an environmental scanning electron microscope (ESEM). The procedure for hydrogen generation was described. It indicated that the cathodic or anodic location gradually changed with the generation of hydrogen bubbles and the formation of corrosion products.

Jian Chen; Jianqiu Wang; Enhou Han; Wei Ke

2008-01-01

302

Effect of heat treatment on microstructures and mechanical properties of extruded-rolled AZ31 Mg alloys  

Microsoft Academic Search

The deformation behaviors of extruded-rolled (ER) AZ31 Mg alloys with different rolling reduction and heat treatment were investigated. The results show that the accumulation of rolling reduction increases the density of twins, and refines the grain structures, which are in accordance with the enhanced strength and degraded plasticity. Tensile strength and plasticity of the alloy depend mainly on rolling reduction,

Wei QIU; En-hou HAN; Lu LIU

2010-01-01

303

3-D simulation of spatial stress distribution in an AZ31 Mg alloy sheet under in-plane compression  

Microsoft Academic Search

A complete 3-D crystal plasticity finite element method (CPFEM) that considered both crystallographic slip and deformation twinning was applied to simulate the spatial distribution of the relative amount of slip and twin activities in a polycrystalline AZ31 Mg alloy during in-plane compression. A microstructure mapping technique that considered the grain size distribution and microtexture measured by electron backscatter diffraction (EBSD)

S.-H. Choi; D. W. Kim; B. S. Seong; A. D. Rollett

2011-01-01

304

77 FR 34934 - Foreign-Trade Zone 139-Sierra Vista, AZ; Application for Reorganization Under Alternative Site...  

Federal Register 2010, 2011, 2012, 2013

...B-43-2012] Foreign-Trade Zone 139--Sierra Vista, AZ; Application for Reorganization Under...FTZ) Board (the Board) by the Sierra Vista Economic Development Foundation, Inc...site: Site 1 (4.7 acres)--Sierra Vista Commerce Center, Highway 90, Sierra...

2012-06-12

305

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

Microsoft Academic Search

BACKGROUND: Nucleosomes are nucleoproteic complexes, formed of eight histone molecules and DNA, and they are responsible for the compaction of the eukaryotic genome. Their presence on DNA influences many cellular processes, such as transcription, DNA replication, and DNA repair. The evolutionarily conserved histone variant H2A.Z alters nucleosome stability and is highly enriched at gene promoters. Its localization to specific genomic

Alain L Gervais; Luc Gaudreau

2009-01-01

306

Effect of temperature of differential speed rolling on room temperature mechanical properties and texture in an AZ31 magnesium alloy  

Microsoft Academic Search

Differential speed rolling (DSR) was applied to the AZ31 magnesium alloy, intended to modify the texture and thus to enhance the room temperature ductility. Especially, effect of DSR temperature on resulting room temperature tensile properties and texture was investigated at a fixed rolling speed ratio of 1.1. The strength was not affected by the rolling temperature: the yield strength and

Hiroyuki Watanabe; Toshiji Mukai; Koichi Ishikawa

2007-01-01

307

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

308

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

309

Effect of microalloying on microstructure and hot working behavior for AZ31 based magnesium alloy  

NASA Astrophysics Data System (ADS)

The formability of Mg alloy sheet in the as-hot rolled condition depends on the microstructure developed during hot rolling. In general, the formability of Mg alloys is improved by finer grain sizes. 'Microalloying' levels of calcium (Ca), strontium (Sr), and cerium (Ce) have been found to refine the as-cast structure, but there is no information as to whether this effect will be reflected in the as-hot worked structure and formability. Thus, in this work, the effects of microalloying levels of calcium (Ca), strontium (Sr), and cerium (Ce) on the microstructures (from as-cast to as-hot rolled) and subsequent hot deformation behavior of AZ31, nominally 3% Al, 1% Zn, and 0.3%Mn, were systematically investigated. To include the effect of solidification rate these alloys were cast in different moulds (preheated steel mould, Cu-mould, and water cooled Cu-mould). One-hit compression testing at temperatures between 250°C ˜ 400 °C, strain rates of 0.001, 0.01, 0.1 s-1 and strains from 0.2 up to 1.0, was performed to investigate the basic hot compression behavior, while two-hit compression testing was conducted to determine the static softening behavior. Hot rolling of the microalloyed AZ31 alloys was then carried out to study the effects of microalloying on as-hot rolled structure under two sets of rolling schedules. To investigate the formability of these microalloyed sheets, tensile tests were completed over a temperature range between ambient and 450°C, at strain rates between 0.1 and 0.0003 s-1. Results show that Ca and Sr act to refine the as cast grain size and the second phases, consistently promoting fine and uniform as-hot rolled grain structure. With regard to grain refinement, calcium has the strongest effect, whereas Ce is most effective for second phase refinement. In addition, microalloying retards grain growth during hot tensile testing. Multiple alloying presents a combined and complementary effect. A refined and uniform grain structure combined with well dispersed and thermally stable second phases significantly improves the hot formability of AZ31 sheets by promoting dynamic recrystallization (DRX) in the matrix, resisting grain coarsening, and retarding the development of cavitation and necking. Under the superplastic condition of 450°C and 0.0003 s -1, the elongation was improved by 17% with Ca only, 26% with Ca and Ce, 51% with Ca and Sr, and 59% with Ca, Sr and Ce.

Shang, Lihong

310

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

311

Proximity of H2A.Z containing nucleosome to the transcription start site influences gene expression levels in the mammalian liver and brain  

PubMed Central

Nucleosome positioning maps of several organisms have shown that Transcription Start Sites (TSSs) are marked by nucleosome depleted regions flanked by strongly positioned nucleosomes. Using genome-wide nucleosome maps and histone variant occupancy in the mouse liver, we show that the majority of genes were associated with a single prominent H2A.Z containing nucleosome in their promoter region. We classified genes into clusters depending on the proximity of H2A.Z to the TSS. The genes with no detectable H2A.Z showed lowest expression level, whereas H2A.Z was positioned closer to the TSS of genes with higher expression levels. We confirmed this relation between the proximity of H2A.Z and expression level in the brain. The proximity of histone variant H2A.Z, but not H3.3 to the TSS, over seven consecutive nucleosomes, was correlated with expression. Further, a nucleosome was positioned over the TSS of silenced genes while it was displaced to expose the TSS in highly expressed genes. Our results suggest that gene expression levels in vivo are determined by accessibility of the TSS and proximity of H2A.Z.

Bargaje, Rhishikesh; Alam, Mohammad Parwez; Patowary, Ashok; Sarkar, Maharnob; Ali, Tamer; Gupta, Shivani; Garg, Manali; Singh, Meghna; Purkanti, Ramya; Scaria, Vinod; Sivasubbu, Sridhar; Brahmachari, Vani; Pillai, Beena

2012-01-01

312

Proximity of H2A.Z containing nucleosome to the transcription start site influences gene expression levels in the mammalian liver and brain.  

PubMed

Nucleosome positioning maps of several organisms have shown that Transcription Start Sites (TSSs) are marked by nucleosome depleted regions flanked by strongly positioned nucleosomes. Using genome-wide nucleosome maps and histone variant occupancy in the mouse liver, we show that the majority of genes were associated with a single prominent H2A.Z containing nucleosome in their promoter region. We classified genes into clusters depending on the proximity of H2A.Z to the TSS. The genes with no detectable H2A.Z showed lowest expression level, whereas H2A.Z was positioned closer to the TSS of genes with higher expression levels. We confirmed this relation between the proximity of H2A.Z and expression level in the brain. The proximity of histone variant H2A.Z, but not H3.3 to the TSS, over seven consecutive nucleosomes, was correlated with expression. Further, a nucleosome was positioned over the TSS of silenced genes while it was displaced to expose the TSS in highly expressed genes. Our results suggest that gene expression levels in vivo are determined by accessibility of the TSS and proximity of H2A.Z. PMID:22821566

Bargaje, Rhishikesh; Alam, Mohammad Parwez; Patowary, Ashok; Sarkar, Maharnob; Ali, Tamer; Gupta, Shivani; Garg, Manali; Singh, Meghna; Purkanti, Ramya; Scaria, Vinod; Sivasubbu, Sridhar; Brahmachari, Vani; Pillai, Beena

2012-07-19

313

From intelligent to smart cities  

Microsoft Academic Search

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

Mark Deakin; Husam Al Waer

2011-01-01

314

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

315

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…

Barrios, Greg

2009-01-01

316

Air pollution in cities  

Microsoft Academic Search

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

Helmut Mayer

1999-01-01

317

Communication externalities in cities  

Microsoft Academic Search

To identify communication externalities in French cities, we exploit a unique survey recording workplace communication of individual workers. Our hypothesis is that in larger and\\/or more educated cities, workers should communicate more. In turn, more communication should have a positive effect on wages. By estimating both an earnings and a communication equation, we find evidence of communication externalities. In larger

Sylvie Charlot; Gilles Duranton

2004-01-01

318

Communication Externalities in Cities  

Microsoft Academic Search

To identify communication externalities in French cities, we exploit a unique survey recording workplace communication of individual workers. Our hypothesis is that in larger and\\/or more educated cities, workers should communicate more. In turn, more communication should have a positive effect on individual wages. By estimating both an earnings and a communication equation, we find evidence of communication externalities. Being

Sylvie Charlot; Gilles Duranton

2003-01-01

319

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

320

European cities: Towards a \\  

Microsoft Academic Search

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

Mathis Stock

2006-01-01

321

Parking, People, and Cities  

Microsoft Academic Search

In this study of how off-street parking requirements affect urban form, we begin by analyzing the relationship between population density and streets in cities. We find that denser cities devote a greater share of their land to streets, but also have less street space per person. This relationship results in part from the difficulty of constructing new streets in built-out

Michael Manville; Donald Shoup

2005-01-01

322

Why Do Cities Shrink?  

Microsoft Academic Search

Cities and regions in different political contexts might play different roles in building communities, but when the cities shrink, they share common elements of what can be characterized as a “shrinkage identity”. One well-documented element is the independence from the country political context and a certain dependence on the effects of globalization on local industries. It can be described as

Diana Reckien; Cristina Martinez-Fernandez

2011-01-01

323

Seattle's Mobile City Project  

Microsoft Academic Search

The City of Seattle's pioneering Mobile City Government Project has received wide attention, since it promises greatly improved fieldwork operations in local government. Three years into operation and with another fieldwork unit in the process of adopting mobile applications, our research studies the work domains of the units involved to better understand the premises, requirements, and effects of fully mobile,

Raya Fidel; Jens-Erik Mai; Kristene Unsworth

324

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

325

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

SciTech Connect

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

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

1999-01-01

326

CO 2 and diode laser welding of AZ31 magnesium alloy  

NASA Astrophysics Data System (ADS)

Magnesium alloys are being increasingly used in automotive and aerospace structures. Laser welding is an important joining method in such applications. There are several kinds of industrial lasers available at present, including the conventional CO 2 and Nd:YAG lasers as well as recently available high power diode lasers. A 1.5 kW diode laser and a 2 kW CO 2 laser are used in the present study for the welding of AZ31 alloys. It is found that different welding modes exist, i.e., keyhole welding with the CO 2 laser and conduction welding with both the CO 2 and the diode lasers. This paper characterizes welds in both welding modes. The effect of beam spot size on the weld quality is analyzed. The laser processing parameters are optimized to obtain welds with minimum defects.

Zhu, Jinhong; Li, Lin; Liu, Zhu

2005-07-01

327

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

328

Femtosecond laser-induced iridescent effect on AZ31B magnesium alloy surface  

NASA Astrophysics Data System (ADS)

Both micro-ripples and nano-ripples were firstly reported at AZ31B magnesium alloy surface irradiated by femtosecond laser in atmospheric environment. Iridescent effect was also demonstrated over a large area of the irradiated surface induced by scanning laser beam. Results revealed that the colour effect was mainly attributed to the nano-ripples with broad distribution of periods acting as diffraction gratings, and intensity of the structural colour was greatly influenced by morphology evolution of the micro-ripples with laser processing. It was suggested that near-field interference between surface plasmons polaritons and incident laser light determined the formation of the nano-ripples, and initial surface roughness combing with such interference lead to the formation of the micro-ripples. Potential applications of such effect on Mg alloys and how to apply the technique to other materials with different properties was further proposed.

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

2013-10-01

329

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

330

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

331

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

SciTech Connect

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

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

2011-10-15

332

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

SciTech Connect

High-level nuclear wastes at the Hanford Site are stored underground in carbon steel double-shell and single-shell tanks. The installation of a prototype corrosion monitoring system into double-shell tank 241-AZ-101 was completed in August, 1996. The system monitors fluctuations in corrosion current and potential (electrochemical noise) occurring on three electrode arrays immersed in the waste liquid and in the vapor space above the waste. The system also supports the use of Tafel and linear polarization resistance testing. By monitoring and analyzing the data from these techniques, changes in the corrosive characteristics of the waste have been rapidly detected and correlated with operational changes in the tank.

Edgemon, G.L., Westinghouse Hanford

1996-12-12

333

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

334

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

NASA Astrophysics Data System (ADS)

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

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

2012-11-01

335

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

336

Laser beam welding of AZ31B-H24 magnesium alloy.  

SciTech Connect

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

Leong, K. H.

1998-09-29

337

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

338

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.

339

Noise in Mexico City  

NASA Astrophysics Data System (ADS)

Mexico City is known to be the largest city in the world, inhabited by some 20 percent of the national population, so noise pollution is not strange to it, particularly in view of the fact that industry is not concentrated, but rather spread throughout the city. The international airport also lies within the city limits, in the midst of residential areas. The heavy traffic during rush hours in the morning and in the evening and the activities of the populace, together with special events, produce a noise problem that is difficult to assess and to solve. Nevertheless, with educational programs begun several years ago and noise campaigns planned for the near future, in addition to existing regulations, the problem is not completely out of control. This paper presents a discussion of the general noise problem and describes how authorities and institutions are dealing with it.

Beristain, Sergio

2001-05-01

340

Design a Solar City  

NSDL National Science Digital Library

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

Integrated Teaching And Learning Program

341

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.; Suzuki, Hiroaki; Iuchi, Kanako

342

Designing the Digital City  

Microsoft Academic Search

The forms that cities take, the ways they function, and the mixes and distributions of activities within them have always\\u000a been influenced very strongly by the capabilities of their underlying network infrastructures. Furthermore, cities have often\\u000a been transformed by the introduction of new infrastructures. It is impossible to imagine Rotterdam without its canals and\\u000a connection to the North Sea, Chicago

William J. Mitchell

2000-01-01

343

Atopia (On Vice City)  

Microsoft Academic Search

It’s like paradise here. Everything seems pastel-hued as you drive by with the radio on. The car is stolen, but so long as\\u000a the police didn’t see you, it won’t matter. Vice City is a nice place (Grand Theft Auto: Vice City 2002). It is not quite utopia. And nor is it some dark dystopia. There’s no\\u000a storyline here where

McKenzie Wark

344

[Cities in peril, Mahgreb].  

PubMed

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

Naciri, M

1994-10-01

345

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

PubMed

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

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

2011-10-12

346

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

347

Corrosion resistance of oxide layers formed on AZ91 Mg alloy in KMnO 4 electrolyte by plasma electrolytic oxidation  

Microsoft Academic Search

The plasma electrolytic oxidation (PEO) process in AZ91 Mg alloy is studied using a solution containing KOH+KF+Na2SiO3 both with and without potassium permanganate (KMnO4). The addition of potassium permanganate to the electrolyte influences coating thickness, surface morphology and the microstructure of oxide layers obtained by the PEO process. Oxide layers formed on AZ91 Mg alloy by the electrolyte containing KMnO4

Duck Young Hwang; Yong Min Kim; Deok-Yong Park; Bongyoung Yoo; Dong Hyuk Shin

2009-01-01

348

On the role of the constitutive model and basal texture on the mechanical behaviour of magnesium alloy AZ31B sheet  

Microsoft Academic Search

The recently developed elastic-viscoplastic self-consistent model with various self-consistent schemes was applied to study\\u000a the effect of basal texture on the mechanical behavior of magnesium alloy AZ31B sheet. The influence of the basal texture\\u000a was investigated using various initial textures generated by artificially tilting the measured texture of the reference AZ31B\\u000a sheet around in a transverse direction. The material parameters

H. Wang; P. D. Wu; K. W. Neale

2010-01-01

349

Repression of Flowering in Arabidopsis Requires Activation of FLOWERING LOCUS C Expression by the Histone Variant H2A.Z  

Microsoft Academic Search

The histone variant H2A.Z has been implicated in numerous chromatin-mediated processes, including transcriptional activation, euchromatin maintenance, and heterochromatin formation. In yeast and humans, H2A.Z is deposited into chromatin by a conserved protein complex known as SWR1 and SRCAP, respectively. Here, we show that mutations in the Arabidopsis thaliana homologs of two components of this complex, ACTIN-RELATED PROTEIN6 (ARP6) and PHOTO-

Roger B. Deal; Christopher N. Topp; Elizabeth C. McKinney; R. B. Meagher

2007-01-01

350

The Nonessential H2A N-Terminal Tail Can Function as an Essential Charge Patch on the H2A.Z Variant N-Terminal Tail  

Microsoft Academic Search

Tetrahymena thermophila cells contain three forms of H2A: major H2A.1 and H2A.2, which make up 80% of total H2A, and a conserved variant, H2A.Z. We showed previously that acetylation of H2A.Z was essential (Q. Ren and M. A. Gorovsky, Mol. Cell 7:1329-1335, 2001). Here we used in vitro mutagenesis of lysine residues, coupled with gene replacement, to identify the sites

Qinghu Ren; Martin A. Gorovsky

2003-01-01

351

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.

352

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

SciTech Connect

In this paper, a constitutive framework based on a crystalline plasticity model is employed to simulate the plastic deformation of AZ31 magnesium alloy, which posses the hexagonal close packed (HCP) crystal structure. Dislocation slip and mechanical twinning are taken into account in the model. The successive integration method is used to determine the active slip systems, and the contribution of twinning to the grain reorientation is treated by the PTR method. The FE model is introduced into ABAQUS/Explicit through a user material subroutine (VUMAT). Three deformation processes of AZ31 magnesium alloy, including tension, compression and a stamping process, are simulated with the present method. The simulation results are compared with experiment and those presented in the literature.

Li Dayong; Peng Yinghong [School of Mechanical and Power Engineering, Shanghai Jiaotong University, 800 Dongchuan Road, Shanghai (China); State Key Laboratory of Mechanical System and Vibration, Shanghai Jiaotong University, 800 Dongchuan Road, Shanghai (China); Zhang Shaorui; Tang Weiqin; Huang Shiyao [School of Mechanical and Power Engineering, Shanghai Jiaotong University, 800 Dongchuan Road, Shanghai (China)

2010-06-15

353

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

354

Characterization of rare-earth conversion films formed on the AZ31 magnesium alloy and its relation with corrosion protection  

NASA Astrophysics Data System (ADS)

Two pre-treatments were studied for AZ31 Mg alloy substrates, consisting of immersion in cerium nitrate and lanthanum nitrate solutions for various immersion times. The surface composition was investigated by X-ray photoelectron spectroscopy and Auger electron spectroscopy that revealed the presence of a surface film containing the rare-earth cation, with a composition which was time dependent in the case of the cerium pre-treatment. The corrosion behaviour of the pre-treated substrates in 0.005 M NaCl solutions was assessed by potentiodynamic polarization, open circuit potential monitoring and the scanning vibrating electrode technique (SVET). The electrochemical results show that the pre-treatments reduced the corrosion activity of the AZ31 Mg alloy substrates in the presence of chloride ions. The corrosion protection efficiency is dependent on the treatment time.

Montemor, M. F.; Simões, A. M.; Carmezim, M. J.

2007-06-01

355

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 1.38±0.04 to 0.84±0.09. 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.

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

2012-01-01

356

The Right to the City  

Microsoft Academic Search

The identity and character of cities in America have been profoundly influenced by race. In the past, laws mandating the segregation of African American and white urban residents through racially discriminatory housing and lending policies created racial geographic boundaries within cities and between cities and suburbs. The impact of this racial segregation in cities can be seen in the creation

Ngai Pindell

2008-01-01

357

Bushehr as an Energic City  

Microsoft Academic Search

Bushehr city is one of the famous city in the south of Iran which is situated in the coastal part of Persian Gulf. This paper try to discuss one of the most important theme which threat the sustainability and comfortability of tomorrow`s life. Changing Bushehr into an Energic city is one of the effective ways to solve the cities problem.

Nasser Sabatsani

2007-01-01

358

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

SciTech Connect

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

WHITE, D.A.

2000-03-01

359

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

360

Corrosion behaviour of Sn-containing oxide layer on AZ91D alloy formed by plasma electrolytic oxidation  

Microsoft Academic Search

Corrosion phenomenon of magnesium alloys is one of the limits for using magnesium alloys in automotive and aerospace industries. The aim of this study is the development of Sn-containing protective oxide coating by a simple plasma electrolytic oxidation in KOH\\/KF\\/Na3PO4 electrolyte on AZ91D magnesium alloy in galvanostatic mode. The film morphology and composition were analysed by SEM coupled with EDS,

C.-E. Barchiche; E. Rocca; J. Hazan

2008-01-01

361

Effect of potassium fluoride on structure and corrosion resistance of plasma electrolytic oxidation films formed on AZ31 magnesium alloy  

Microsoft Academic Search

Plasma electrolytic oxidation films on AZ31 magnesium alloy were prepared in silicate–KOH–glycol (base electrolyte) electrolyte with the addition of different KF concentration. The effect of KF on the characteristic of discharge in electrolytes was studied. The compositions, structures and morphologies of the oxide films formed in different KF concentration were determined by energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD)

Li Wang; Li Chen; Zongcheng Yan; Honglin Wang; Jiazhi Peng

2009-01-01

362

Effect of plasma electrolytic oxidation coating on the stress corrosion cracking behaviour of wrought AZ61 magnesium alloy  

Microsoft Academic Search

An attempt was made to understand the effect of silicate based plasma electrolytic oxidation (PEO) coating on the stress corrosion cracking (SCC) behaviour of an AZ61 wrought magnesium alloy. The SCC behaviour of untreated and PEO coated specimens was assessed using slow strain rate tensile tests at two different nominal strain rates, viz. 1×10?6s?1 and 1×10?7s?1, in ASTM D1384 test

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

2008-01-01

363

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

Microsoft Academic Search

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

Hongping Duan; Chuanwei Yan; Fuhui Wang

2007-01-01

364

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

365

Submillimeter Array Identification of the Millimeter-selected Galaxy SSA22-AzTEC1: A Protoquasar in a Protocluster?  

NASA Astrophysics Data System (ADS)

We present results from Submillimeter Array (SMA) 860 ?m subarcsecond astrometry and multiwavelength observations of the brightest millimeter (S 1.1mm = 8.4 mJy) source, SSA22-AzTEC1, found near the core of the SSA22 protocluster that is traced by Ly?-emitting galaxies at z = 3.09. We identify a 860 ?m counterpart with a flux density of S 860 ?m = 12.2 ± 2.3 mJy and absolute positional accuracy that is better than 0farcs3. At the SMA position, we find radio-to-mid-infrared counterparts, whilst no object is found in Subaru optical and near-infrared deep images at wavelengths <=1 ?m (J > 25.4 in AB, 2?). The photometric redshift estimate, using flux densities at >=24 ?m, indicates z phot = 3.19+0.26 -0.35, consistent with the protocluster redshift. We then model the near-to-mid-infrared spectral energy distribution (SED) of SSA22-AzTEC1, and find that the SED modeling requires a large extinction (AV ? 3.4 mag) of starlight from a stellar component with M star ~ 1010.9 M sun, assuming z = 3.1. Additionally, we find a significant X-ray counterpart with a very hard spectrum (?eff = -0.34+0.57 -0.61), strongly suggesting that SSA22-AzTEC1 harbors a luminous active galactic nuclei (AGNs; LX ? 3 × 1044 erg s-1) behind a large hydrogen column (N H ~ 1024 cm-2). The AGN, however, is responsible for only ~10% of the bolometric luminosity of the host galaxy, and therefore the star formation activity likely dominates the submillimeter emission. It is possible that SSA22-AzTEC1 is the first example of a protoquasar growing at the bottom of the gravitational potential underlying the SSA22 protocluster.

Tamura, Y.; Iono, D.; Wilner, D. J.; Kajisawa, M.; Uchimoto, Y. K.; Alexander, D. M.; Chung, A.; Ezawa, H.; Hatsukade, B.; Hayashino, T.; Hughes, D. H.; Ichikawa, T.; Ikarashi, S.; Kawabe, R.; Kohno, K.; Lehmer, B. D.; Matsuda, Y.; Nakanishi, K.; Takata, T.; Wilson, G. W.; Yamada, T.; Yun, M. S.

2010-12-01

366

AzTEC Millimetre Survey of the COSMOS field - II. Source count overdensity and correlations with large-scale structure  

Microsoft Academic Search

We report an overdensity of bright submillimetre galaxies (SMGs) in the 0.15 deg2 AzTEC\\/COSMOS survey and a spatial correlation between the SMGs and the optical-IR galaxy density at z <~ 1.1. This portion of the COSMOS field shows a ~3sigma overdensity of robust SMG detections when compared to a background, or `blank-field', population model that is consistent with SMG surveys

J. E. Austermann; I. Aretxaga; D. H. Hughes; Y. Kang; S. Kim; J. D. Lowenthal; T. A. Perera; D. B. Sanders; K. S. Scott; N. Scoville; G. W. Wilson; M. S. Yun

2009-01-01

367

Electroless nickel-plating on AZ91D magnesium alloy: effect of substrate microstructure and plating parameters  

Microsoft Academic Search

Electroless nickel-plating on AZ91D magnesium alloy has been investigated to understand the effect of substrate microstructure and plating parameters. The initial stage of the deposition was investigated using scanning electron microscopy (SEM) and energy dispersive X-ray analysis on substrates plated for a very short interval of time. The early stage of growth was strongly influenced by the substrate microstructure. Plating

Rajan Ambat; W Zhou

2004-01-01

368

The influence of the as-hot rolled microstructure on the elevated temperature mechanical properties of magnesium AZ31 sheet  

Microsoft Academic Search

An AZ31 alloy was rolled at temperatures between 350 and 450°C, after soaking at rolling temperature for either 1 or 10h, using various rolling reductions per pass and rolling speeds. Two extremes of as-hot rolled microstructure were generated: (i) a banded structure comprised of very fine equiaxed grains, but with a few ‘pancaked grains’, i.e. ‘partially recrystallized’, and (ii) much

G. Vespa; L. W. F. Mackenzie; R. Verma; F. Zarandi; E. Essadiqi; S. Yue

2008-01-01

369

Application of X-ray microtomography to analysis of cavitation in AZ61 magnesium alloy during hot deformation  

Microsoft Academic Search

The efficiency of particles in acting as cavity formation sites during hot deformation was investigated for a fine-grained wrought magnesium–aluminium–zinc (AZ series) alloy using X-ray micro tomography. Two methodologies were developed to determine the particle\\/cavity association from 3-dimensional data, each clearly demonstrating that particles act as a major formation site for cavitation. The particles forming cavities were identified and characterised.

H. M. M. A. Rashed; J. D. Robson; P. S. Bate; B. Davis

2011-01-01

370

Post-heat Treatment Effects on Cold-Sprayed Aluminum Coatings on AZ91D Magnesium Substrates  

NASA Astrophysics Data System (ADS)

Commercially pure aluminum (CP-Al) powder was deposited by the cold spray process onto AZ91D magnesium (Mg) substrates that had been subjected to three different heat-treatment conditions: namely, as-cast (F), homogenized (T4), and artificially aged (T6). The substrate hardness was measured to be 80.7 ± 1.8, 73.7 ± 4.0, and 103.6 ± 7.4 HV0.025 for the F-, T4-, and T6-Mg alloy substrates respectively. Thick (~400 ?m) and dense (below 1% porosity) Al coatings have been obtained. After post-deposition heat treatment at 400 °C, the intermetallic Mg17Al12 (?) and Al3Mg2 (?) phases with different thicknesses were found to have formed at the coating/substrate interface depending on the holding time. While no significant thickness differences of the intermetallic layers were detected in the cases of F- and T6-AZ91D substrates, thicker layers formed on the T4-AZ91D substrate. It is believed that the higher Al concentration in the T4-AZ91D solid solution within the ?-Mg could diffuse and contribute more easily to the growth of the intermetallic phases. The hardness of the ?- and ?-phase was measured to be 260.5 ± 10.7 HV0.025 and 279.6 ± 13.7 HV0.025, respectively. Shear strength test results revealed lower adhesion strength after heat treatment, which is attributed to the presence of brittle intermetallic layers at the coating/substrate interface.

Bu, Hengyong; Yandouzi, Mohammed; Lu, Chen; Jodoin, Bertrand

2012-06-01

371

Microstructure and corrosion characteristics of laser-alloyed magnesium alloy AZ91D with Al Si powder  

Microsoft Academic Search

Blown-powder laser surface alloying was performed on the magnesium alloy AZ91D with Al-Si alloy powder to improve corrosion resistance. Characterization by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and x-ray diffraction (XRD) analysis revealed that intermetallic compounds (IMCs) of Mg2Si, Al12Mg17 and Al3Mg2 were formed in the matrix of alpha-Mg and Al solid solutions in Al-Si alloyed layers. The

Ming Qian; Da Li; Chang Jin

2008-01-01

372

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

Microsoft Academic Search

Characterization of the material mechanical behavior at sub-Hopkinson regime (0.1 to 1000 s¹) is very challenging due to instrumentation limitations and the complexity of data analysis involved in dynamic loading. In this study, AZ31 magnesium alloy sheet specimens are tested using a custom designed servo-hydraulic machine in tension at nominal strain rates up to 1000 s¹. In order to resolve

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

2011-01-01

373

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

SciTech Connect

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

WHITE, D.A.

2000-01-27

374

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

Microsoft Academic Search

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

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

1994-01-01

375

Evaluation of the anti-corrosive effect of acid pickling and sol–gel coating on magnesium AZ31 alloy  

Microsoft Academic Search

The effect of different acid pre-treatment procedures on the corrosion of magnesium AZ31 alloy was compared by measuring the amount of hydrogen gas formed when the surface was in contact with aqueous 5% sodium chloride solution. A 4–7?m thick sol–gel coating prepared by phosphoric acid catalyzed sol–gel processing of a methyltriethoxysilane\\/tetraethoxysilane mixture was applied to the differently pre-treated magnesium surfaces.

Ralf Supplit; Thomas Koch; Ulrich Schubert

2007-01-01

376

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

NASA Astrophysics Data System (ADS)

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

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

2011-04-01

377

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

NASA Astrophysics Data System (ADS)

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

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

2012-01-01

378

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

PubMed Central

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

Updike, Dustin L; Mango, Susan E

2006-01-01

379

Közvetlen értékesítés az egri borászatokban  

Microsoft Academic Search

A tanulmány a magyar szőlő-bor ágazatban vizsgálja a közvetlen értékesítés elterjedtségét, valamint a borászok erre való hajlandóságát. A kérdőíves vizsgálat 2010-ben az Egri borvidéken zajlott, melynek eredményei azt mutatták, hogy jelentős eltérés figyelhető meg az egyes borászatok között abban, hogy milyen mértékben és milyen hatékonyan alkalmazzák a közvetlen értékesítés különböző formáit.1 A borok közvetlen értékesítésének legfontosabb eredménye az, hogy megszűnik

Daniel Gyore

2011-01-01

380

Microstructure and corrosion characteristics of laser-alloyed magnesium alloy AZ91D with Al Si powder  

NASA Astrophysics Data System (ADS)

Blown-powder laser surface alloying was performed on the magnesium alloy AZ91D with Al-Si alloy powder to improve corrosion resistance. Characterization by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and x-ray diffraction (XRD) analysis revealed that intermetallic compounds (IMCs) of Mg2Si, Al12Mg17 and Al3Mg2 were formed in the matrix of ?-Mg and Al solid solutions in Al-Si alloyed layers. The anodic polarization test in 3.5% NaCl aqueous solution showed that preferential corrosion occurred in the ?-Mg matrix of the AZ91D base metal. The Al-Si alloyed layers exhibited a lower corrosion rate and a higher polarization resistance than AZ91D. The compactly dispersed dendritic Mg2Si phase, and the dendritic and angular phases of Al12Mg17 and Al3Mg2 in the alloyed microstructure were observed to be corrosion-resistant, constituting a barrier that retards corrosion. Corrosion initiated at the interface between IMCs and the solid solution matrix, and at substructures of the matrix, subsequently pervaded into the surrounding microstructure.

Qian, Ming; Li, Da; Jin, Chang

2008-04-01

381

AZ960, a novel Jak2 inhibitor, induces growth arrest and apoptosis in adult T-cell leukemia cells.  

PubMed

Adult T-cell leukemia/lymphoma (ATL) is a highly aggressive disease in which the Jak2/Stat5 pathway is constitutively activated. This study found that AZ960, a novel inhibitor of Jak2 kinase, effectively induced growth arrest and apoptosis of human T-cell lymphotropic virus type 1, HTLV-1-infected T cells (MT-1 and MT-2) in parallel with downregulation of the phosphorylated forms of Jak2 and Bcl-2 family proteins including Bcl-2 and Mcl-1. Interestingly, AZ960 increased levels of Bcl-xL in MT-1 and MT-2 cells in association with accumulation of cAMP response element-binding protein bound to the Bcl-xL promoter as measured by chromatin immunoprecipitation assay. Importantly, genetic inhibition of Bcl-xL by a small interfering RNA potentiated antiproliferative effects of AZ960 in MT-1 cells. Taken together, Jak2 is an attractive molecular target for treatment of ATL. Concomitant blockade of Jak2 and Bcl-xL may be a promising treatment strategy for this lethal disease. PMID:21159615

Yang, Jing; Ikezoe, Takayuki; Nishioka, Chie; Furihata, Mutsuo; Yokoyama, Akihito

2010-12-01

382

Antibiotic Attack (Kinetic City)  

NSDL National Science Digital Library

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

American Association for the Advancement of Science (;)

2005-01-01

383

The knowledge that shapes the city: The human city beneath the social city  

Microsoft Academic Search

Abstract In the Atlanta Symposium (Hillier, 2001, 2003a) a theory of the social construction ofthe city was presented. In this paper it is proposed that underlying the various kinds of social city there is a deeper, more generic human city, which arises from the pervasive intervention of the human,cognitive subject in the shaping and working of the city. This intervention

Bill Hillier

384

THE AzTEC/SMA INTERFEROMETRIC IMAGING SURVEY OF SUBMILLIMETER-SELECTED HIGH-REDSHIFT GALAXIES  

SciTech Connect

We present results from a continuing interferometric survey of high-redshift submillimeter galaxies (SMGs) with the Submillimeter Array, including high-resolution (beam size approx2 arcsec) imaging of eight additional AzTEC 1.1 mm selected sources in the COSMOS field, for which we obtain six reliable (peak signal-to-noise ratio (S/N) >5 or peak S/N >4 with multiwavelength counterparts within the beam) and two moderate significance (peak S/N >4) detections. When combined with previous detections, this yields an unbiased sample of millimeter-selected SMGs with complete interferometric follow up. With this sample in hand, we (1) empirically confirm the radio-submillimeter association, (2) examine the submillimeter morphology-including the nature of SMGs with multiple radio counterparts and constraints on the physical scale of the far infrared-of the sample, and (3) find additional evidence for a population of extremely luminous, radio-dim SMGs that peaks at higher redshift than previous, radio-selected samples. In particular, the presence of such a population of high-redshift sources has important consequences for models of galaxy formation-which struggle to account for such objects even under liberal assumptions-and dust production models given the limited time since the big bang.

Younger, Joshua D.; Fazio, Giovanni G.; Huang Jiasheng; Ashby, Matthew L. N.; Gurwell, Mark A.; Petitpas, Glen R.; Wilner, David J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Yun, Min S.; Wilson, Grant W.; Scott, Kimberly S.; Austermann, Jason; Perera, Thushara [Astronomy Department, University of Massachusetts, Amherst, MA 01003 (United States); Peck, Alison B. [Joint ALMA Office, El Golf 40, Las Condes, Santiago 7550108 (Chile); Hughes, David H.; Aretxaga, Itziar [Instituto Nacional de AstrofIsica, Optica y Electronica (INAOE), Tonantzintla, Peubla (Mexico); Kim, Sungeun [Astronomy and Space Sciences Department, Sejong University, 98 Kwangjin-gu, Kunja-dong, Seoul 143-747 (Korea, Republic of); Lowenthal, James D., E-mail: jyounger@ias.ed [Astronomy Department, Smith College, Clark Science Center, Northampton, MA 01060 (United States)

2009-10-10

385

Effects of Zr Additions on the Microstructure and Impression Creep Behavior of AZ91 Magnesium Alloy  

NASA Astrophysics Data System (ADS)

The effects of 0.2, 0.6, and 1.0 wt pct Zr additions on the microstructure and creep behavior of AZ91 Mg alloy were investigated by impression tests carried out under constant punching stress ( ? imp) in the range 100 to 650 MPa, corresponding to the modulus-compensated stress levels of {{0.007 le ?_{{imp}} } {G le 0.044}} , at temperatures in the range 425 K to 570 K (152 °C to 297 °C). The alloy containing 0.6 wt pct Zr showed the best creep resistance mainly due to the favorable formation of Al3Zr2 and Al2Zr intermetallic compounds, reduction in the volume fraction of the eutectic ?-Mg17Al12 phase, and solid solution hardening effects of Al in the Mg matrix. Based on the obtained stress exponents of 4.2 to 6.5 and activation energies of 90.7 to 127.1 kJ/mol, it is proposed that two parallel mechanisms of lattice and pipe-diffusion-controlled dislocation climb compete. Dislocation climb controlled by dislocation pipe diffusion prevails at high stresses, whereas climb of edge dislocations is the controlling mechanism at low stresses.

Kabirian, F.; Mahmudi, R.

2010-12-01

386

Grain Growth in Multiple Scales of Polycrystalline AZ31 Magnesium Alloy by Phase-Field Simulation  

NASA Astrophysics Data System (ADS)

A multiscale phase-field model was established on the assumption of an isotropic single-phase system to simulate the realistic spatiotemporal process of grain growth for polycrystalline Mg-Al-Zn alloy AZ31, especially to determine the mechanisms for unique nanostructure evolution. The expression of the local free energy density function was improved according to different driving forces. The grain boundary range and grain boundary energy were studied in each scale to determine the correct gradient and coupling parameters, respectively. It is shown that the grain boundary energy in nanoscales is lower down to about half that in the micron scale, the time exponent n in the kinetic equation is varied from 5 to 2 from the nanograins to the micrograins, and the grain growth rate in nanoscale is much slower in an order of magnitude than that in the micron scale. These findings can be proven by the limited experimental results in the literature. Simulations expose that the solute atoms like to segregate at the grain boundaries much more severely in nanostructure than that in conventional microstructure, and this may be the reason why nanostructure shows a low boundary mobility to result in a strange low grain growth rate at up to an initial long annealing time.

Wu, Y.; Zong, B. Y.; Zhang, X. G.; Wang, M. T.

2013-03-01

387

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

NASA Astrophysics Data System (ADS)

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 becomes unstable (serrated) at temperatures of 4.2-25 K and more stress jerks occur in the SPD polycrystal than in the SC alloy. The temperature dependence of the yield stress of the alloy is typical of thermally activated unpinning of dislocations from short-range barriers. The ratio of the yield stresses for the SPD and SC alloys at a given temperature is explained by hardening owing to a reduction in grain size and softening owing to a favorable texture. As the grain size is reduced, the rate of strain hardening of the alloy falls off, but its ductility (strain to fracture) increases because of the texture. The strain rate sensitivity of the alloy for T<=100 K is independent of microstructure and is determined by intersections with forest dislocations. As the temperature is raised over 150-295 K the strain rate sensitivity becomes greater owing to activation of dynamic recovery and an enhanced contribution from diffusion processes during plastic deformation of micrograined materials.

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

2010-12-01

388

The Effect of Mn-rich Precipitates on the Strength of AZ31 Extrudates  

NASA Astrophysics Data System (ADS)

The commercial magnesium alloy AZ31 has been subjected to a range of solution treatment regimes. These have then been extruded and their microstructure, texture, and precipitate populations characterized along with their mechanical properties. During the solution treatment, Mn-enriched particles develop and these remain largely unchanged throughout subsequent processing steps. A direct link between grain size and texture has been found, with coarser-grained specimens showing sharper textures. VPSC modeling has been used to quantify the effect of texture on the tensile yield strength, and it has been found that sharper textures have larger tensile yield strengths. Since coarser grain sizes have reduced Hall-Petch hardening, but have an additional texture-strengthening component, a region on the Hall-Petch plot for tension has been identified in which there is an insensitivity of strength to grain size. This has been quantitatively modeled and a texture-modified Hall-Petch plot for tension has been developed. The Mn-rich particles have also been shown to provide precipitate strengthening to the alloy of up to 40 MPa. The compressive behavior was clearer, with the compressive yield strength being directly correlated to grain size and unaffected by texture or precipitation hardening.

Stanford, Nicole; Atwell, Dale

2013-10-01

389

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

NASA Astrophysics Data System (ADS)

The fatigue crack growth behavior of an AZ31 magnesium alloy was investigated by comparing the effect of zirconate and phosphate chemical liquids. The morphology, components, and phase compositions of the chemical depositions at the fatigue crack tip were analyzed by employing scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD), respectively. For samples with and without the chemical liquids, their stress-intensity factor values at the fatigue crack tip were compared by using a stress-strain gauge. The results demonstrated that a zirconate film (Zr x O y ·Zn x O y ) and a phosphate film (Zn3(PO4)2·4H2O and MgZnP2O7) could be formed on the fatigue crack-surface at the fatigue crack tip. The stress distribution was changed because of the chemical depositions and the causticity of the chemical liquids. This could decrease the stress-intensity factor value and thus effectively cause fatigue crack closure, which reduces the fatigue crack growth rate. Moreover, it was found that the fatigue crack closure effect of zirconates was more positive than that of phosphates.

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

2012-03-01

390

Fatigue Life Prediction of Rolled AZ31 Magnesium Alloy Using AN Energy-Based Model  

NASA Astrophysics Data System (ADS)

Fatigue behavior of rolled AZ31 magnesium alloy, which shows an anisotropic deformation behavior due to the direction dependent formation of deformation twins, was investigated by carrying out stress and strain controlled fatigue tests. The anisotropy in deformation behavior introduced asymmetric stress-strain hysteresis hoops, which make it difficult to use common fatigue life prediction models, such as stress and strain-based models, and induced mean stress and/or strain even under fully-reversed conditions; the tensile mean stress and strain were found to have a harmful effect on the fatigue resistance. An energy-based model was used to describe the fatigue life behavior as strain energy density was stabilized at the early stage of fatigue life and nearly invariant through entire life. To account for the mean stress and strain effects, an elastic energy related to the mean stress and a plastic strain energy consumed by the mean strain were appropriately considered in the model. The results showed that there is good agreement between the prediction and the experimental data.

Park, Sung Hyuk; Hong, Seong-Gu; Lee, Byoung Ho; Lee, Chong Soo

391

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

392

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

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

393

Investigation of the gas-jet ejector in KamAZ trucks  

SciTech Connect

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

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

1984-03-01

394

A fajtacsoport szerepe az alföldi juhászatok eredményeiben  

Microsoft Academic Search

A vizsgált juhászatok a hazai átlagtól eltérő fajtaösszetételűek és nagyobb nyájméretűek, de a nagyobb állományokhoz korszerűtlen technológia társul, ami korlátozza a potenciális hozamok elérését. A költségek szerkezetéből kitűnik, hogy a takarmányköltségek mellett a személyi jellegű költségek aránya igen magas a vizsgált gazdaságok állománykoncentrációja ellenére is, ami utal az évtizedek óta elavult tartástechnológiára is. A fajtacsoportonkénti bevételekben szembetűnő a tejelő juhászatok

Istvan Monori

2010-01-01

395

Transition of dominant diffusion process during superplastic deformation in AZ61 magnesium alloys  

NASA Astrophysics Data System (ADS)

The superplastic behavior of the AZ61 magnesium alloy sheet, processed by one-step hot extrusion and possessing medium grain sizes of ˜12 µm, has been investigated over the temperature range of 523 to 673 K. The highest superplastic elongation of 920 pct was obtained at 623 K and a deformation rate of 1×10-4 s-1. In the lower and higher strain rate regimes, with apparent m values of ˜0.45 and ˜0.25, respectively, grain-boundary sliding (GBS) and dislocation creep appeared to dominate the deformation, consistent with the scanning electron microscopy (SEM) examination. The SEM examination also revealed that individual GBS started to operate from the very initial deformation stage in the strain rate range with m˜0.45, which was attributed to the relatively high fraction (88 pct) of high-angle boundaries. The analyses of the superplastic data over 523 to 673 K and 5×10-5 to 1×10-3 s-1 revealed a true stress exponent of ˜2, and the activation energy was close to that for grain-boundary and lattice diffusion of magnesium at 523 to 573 K and 573 to 673 K, respectively. The transition temperature of activation energy is ˜573 K, which is attributed to the change in the dominant diffusion process from grain-boundary diffusion to lattice diffusion. It is demonstrated that the effective diffusion coefficient is a valid parameter to characterize the superplastic behavior and the dominant diffusion process.

Wang, Y. N.; Huang, J. C.

2004-02-01

396

Lap Fillet Welding of Thin Sheet AZ31 Magnesium Alloy with Pulsed Nd:YAG Laser  

NASA Astrophysics Data System (ADS)

In recent years, reducing the size and weight of consumer products requires the joining of thin sheets of magnesium alloys with both thickness and joining area of less than 1mm, especially for packaging purposes. Conventional welding processes are difficult to joint a thin sheet magnesium alloy because of high heat input, which in turns leads to various problems such as burn through and cracks. In this study, lap fillet welding of thin sheet magnesium alloy AZ31B with a thickness of 0.3 mm has been carried out using a pulsed Nd:YAG laser beam. The influences of gap, laser beam center location and scan speed on joint appearances have been investigated. It was found that defects were significantly reduced when the gap width was less than 35 µm when the laser beam center was located just on the edge of the upper specimen (x=0), and scan speed was varied from 400 to 450 m/min. Wider bond width at average value of 300 µm was achieved when the beam center was at x=0 with a wide range of scan speeds from 250 to 450 mm/min compared with the cases at x=-0.1 and -0.2 mm from edge. Increases in bond width and minimal defects at x=0 improve fracture load by 68% compared with those at x=-0.1 mm.

Ishak, Mahadzir; Yamasaki, Kazuhiko; Maekawa, Katsuhiro

397

Reproducing in cities.  

PubMed

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 started recently and has been dramatic in some cities. Here it is argued that both historical and evolutionary demographers are interpreting fertility declines across the globe in terms of the relative costs of child rearing, which increase to allow children to outcompete their peers. Now largely free from the fear of early death, postindustrial societies may create an environment that generates runaway parental investment, which will continue to drive fertility ever lower. PMID:18258904

Mace, Ruth

2008-02-01

398

Iowa City Electric Franchise: Report to the City Manager.  

National Technical Information Service (NTIS)

The Iowa City electric franchise is analyzed on the bases of historical, economic, and policy issues. Information on past franchise renewals in Iowa City is presented and franchise practices are compared with those in other jurisdictions. Franchise fees a...

M. F. Sheehan

1982-01-01

399

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

400

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

401

Homage to Atlantic City  

PubMed Central

In this article, I reflect on the unique value for the societies of academic internal medicine of their annual spring meetings that were held in Atlantic City for two generations prior to 1977 and consider whether lessons remain from those past experiences.

Jr., Lloyd H. Smith

2008-01-01

402

Making Cities Green.  

ERIC Educational Resources Information Center

|Describes several examples of urban parks and the renewal of city open spaces. Community groups interested in getting funding from government or private sources must cope with budget restrictions by making effective, innovative use of available money. Government agencies with funds allocated for urban improvements are mentioned. (AM)|

Goldstein, Neil B.; Engel, Jane

1981-01-01

403

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

404

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

405

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

406

Consumption and City Fragmentation  

Microsoft Academic Search

The majority of the world population now lives in cities, a very dynamic socio-spatial reality with hubs of communication networks, large concentrations of finance and other economic activities, serving as arrival points for populations of different origins, composed of multicultural societies, and simultaneously the domain of freedom and wealth as well as the homeland of exclusion and despair. Diversity and

Teresa Barata Salgueiro

407

Problems of classified cities  

Microsoft Academic Search

Analysed is the economy of classified spatial-administrative units of Russia formed in the Soviet period to provide national security with a nuclear shield. The change of priorities in favour of nuclear disarmament has brought financial and economic instability to major enterprises of the Atomic Ministry and economic depression to the classified cities. The author examines reasons for which the law

L. V. Koval

2002-01-01

408

City Kids Go Green.  

ERIC Educational Resources Information Center

|Describes Outward Bound Urban Resources Initiative, a six-week summer course whose goal is to work with urban youth to develop solutions for local environmental problems. Among the activities described include converting city lots into parks, neighborhood cleanup, and tree planting. (MDH)|

Taylor, Tricia

1993-01-01

409

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

410

New City, New Challenges  

ERIC Educational Resources Information Center

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

Matthews, Frank

2010-01-01

411

India's Cities in Crisis.  

ERIC Educational Resources Information Center

|Indian cities are growing rapidly due to natural increase and migration from rural areas. This has caused huge pollution problems and has resulted in overcrowded schools and hospitals. Conflict between religious groups has increased; so has crime. India is modernizing, but not fast enough. (CS)|

Bryjak, George J.

1984-01-01

412

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

413

Multilingual Virtual City Guides  

Microsoft Academic Search

In this paper the potential of combining low cost systems with technologies for modelling and rendering populated urban scenes and multilingual interactive avatars is presented. As an example, a medieval European city was recreated, such that within this virtual environment, visitors can see for themselves how buildings look and hear from a multilingual interactive guide the history of the place.

Karina Rodriguez Echavarria; Michel Genereux; David B. Arnold; Andrew M. Day; John R. W. Glauert

414

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

415

21 Cities- A National Perspective on Center City Transportation.  

National Technical Information Service (NTIS)

The report is a synopsis of comment from representatives of 21 cities during a 15 month process of intensive communication focused on the public transportation problems in center cities across the country. The project involved the 21 cities in the develop...

1970-01-01

416

Healthy Cities: a guide to the literature.  

PubMed Central

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

Kenzer, M

2000-01-01

417

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

SciTech Connect

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

Geeting, John GH; Hallen, Richard T.

2005-02-15

418

Gary Model Cities Health Planning.  

National Technical Information Service (NTIS)

Health planning in the Gary, Indiana, Model Cities target area is described. Efforts to involve citizens in the Model Cities program are noted, including the designation of non-profit resident and professional health boards to administer each health progr...

1971-01-01

419

Bushehr as an Energic City  

NASA Astrophysics Data System (ADS)

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

Sabatsani, Nasser

420

Clean Cities National Partner Awards  

SciTech Connect

U. S. DOE Clean Cities Program has awarded its National Partner awards for 2002, and the awards will be presented at the Clean Cities Conference in May 2002. This fact sheets describe the winners and their contributions.

Not Available

2002-05-01

421

Presystemic metabolism of AZ'0908, a novel mPGES-1 inhibitor: an in vitro and in vivo cross-species comparison.  

PubMed

AZ'0908 is a novel microsomal prostaglandin E synthase-1 inhibitor intended for oral administration. Pharmacokinetic experiments in rats showed that bioavailability was much lower than anticipated and increased following pretreatment with the nonspecific cytochrome P450 (CYP) inhibitor 1-aminobenzotriazole, presumably by inhibition of intestinal metabolism. Stability experiments in rat liver and intestinal fractions revealed that the intrinsic clearance (Cl(int)) was much higher in intestinal than in liver microsomes. Caco2 experiments showed that AZ'0908 was a substrate for breast cancer resistance protein. Permeability was generally high and the efflux component was saturable predicting good absorption. The Cl(int) values in human intestinal microsome and S9 fractions were low. A correlation occurred between in vitro intestinal metabolism and in vivo intestinal loss in rats and dogs. Enzyme identification experiments showed that human CYP2J2 was involved in the oxidation of AZ'0908. In rats, the major metabolic enzyme was not identified. However, rat CYP2J2 analogs were not investigated. Intestinal metabolism appeared to be a major occurrence, explaining intestinal loss of AZ'0908 in the rats. In view of good overall permeability, low in vitro intestinal turnover, and relative low intestinal abundance of CYP2J2, we predict that intestinal metabolism of AZ'0908 in human does not exert a major issue. PMID:23316000

Bylund, Johan; Bueters, Tjerk

2013-01-11

422

Smart cities and service integration  

Microsoft Academic Search

E-government advancements have not fully resolved the challenge of providing citizens with a single entry point for services that involve different government entities. The Smart Cities and Service Integration project (hereafter, SmartCities) aims to establish a framework for smart city service integration that would assist in the management of large scale projects related to the integration of services across governments.

Taewoo Nam; Francisco Armando Aldama; Hafedh Chourabi; Sehl Mellouli; Theresa A. Pardo; J. Ramon Gil-Garcia; Hans Jochen Scholl; Adegboyega Ojo; Elsa Estevez; Lei Zheng

2011-01-01

423

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

424

City Branding: Gold Coast Australia  

Microsoft Academic Search

City branding is a relatively new area of academic research in marketing. Previous research has focused on city brand images and particularly the contrast in brand image across cities. Essentially this reflects the interest of policy makers in developing sound competitive brand positions, with the aim of achieving a competitive advantage. The current paper shifts the focus to explaining the

Dale Miller; Carmel Herington; Bill Merrilees

425

Mexico-US Border Cities  

Microsoft Academic Search

Background: HIV prevalence is increasing among female sex work- ers (FSWs) in Tijuana and Ciudad Juarez, 2 Mexican cities on the US border. Quasilegal prostitution in both cities attracts large numbers of sex tourists. We compared FSWs with and without US clients in both cities. Methods: FSWs aged >18 years reporting unprotected sex with >1 client within the last 2

STEFFANIE A. STRATHDEE; REMEDIOS LOZADA; SHIRLEY J. SEMPLE; MINYA PU; HUGO STAINES-OROZCO; MIGUEL FRAGA-VALLEJO; HORTENSIA AMARO; ADELA DELATORRE; CARLOS MAGIS-RODRõ ´ GUEZ; THOMAS L. PATTERSON

426

Controlling the degradation rate of AZ91 magnesium alloy via sol-gel derived nanostructured hydroxyapatite coating.  

PubMed

Magnesium (Mg) alloys have been introduced as new generation of biodegradable orthopedic materials in recent years since it has been proved that Mg is one of the main minerals required for osseous tissue revival. The main goal of the present study was to establish a desired harmony between the necessities of orthopedic patient body to Mg(2+) ions and degradation rate of the Mg based implants as a new class of biodegradable/bioresorbable materials. This prospect was followed by providing a sol-gel derived nanostructured hydroxyapatite (n-HAp) coating on AZ91 alloy using dip coating technique. Phase structural analysis, morphology study, microstructure characterization, and functional group identification were performed using X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. The prepared samples were immersed in simulated body fluid in order to study the formation of apatite-like precipitations, barricade properties of the n-HAp coating, and to estimate the dosage of released Mg(2+) ions within a specified and limited time of implantation. Electrochemical polarization tests were carried out to evaluate and compare the corrosion behavior of the n-HAp coated and uncoated samples. The changes of the in vitro pH values were also evaluated. Results posed the noticeable capability of n-HAp coating on stabilizing alkalization behavior and improving the corrosion resistance of AZ91 alloy. It was concluded that n-HAp coated AZ91 alloy could be a good candidate as a type of biodegradable implant material for biomedical applications. PMID:23910282

Rojaee, Ramin; Fathi, Mohammadhossein; Raeissi, Keyvan

2013-05-15

427

77 FR 40798 - Safety Zone; Nautical City Festival Air Show, Rogers City MI  

Federal Register 2010, 2011, 2012, 2013

...Nautical City Festival Air Show, Rogers City MI AGENCY: Coast Guard, DHS...Nautical City Festival Air Show, Rogers City MI; in the Federal Register...be launched to the east of the Rogers City marina. The Captain of the...

2012-07-11

428

SUBMILLIMETER ARRAY IDENTIFICATION OF THE MILLIMETER-SELECTED GALAXY SSA22-AzTEC1: A PROTOQUASAR IN A PROTOCLUSTER?  

SciTech Connect

We present results from Submillimeter Array (SMA) 860 {mu}m subarcsecond astrometry and multiwavelength observations of the brightest millimeter (S{sub 1.1mm} = 8.4 mJy) source, SSA22-AzTEC1, found near the core of the SSA22 protocluster that is traced by Ly{alpha}-emitting galaxies at z = 3.09. We identify a 860 {mu}m counterpart with a flux density of S{sub 860{sub {mu}m}} = 12.2 {+-} 2.3 mJy and absolute positional accuracy that is better than 0.''3. At the SMA position, we find radio-to-mid-infrared counterparts, whilst no object is found in Subaru optical and near-infrared deep images at wavelengths {<=}1 {mu}m (J > 25.4 in AB, 2{sigma}). The photometric redshift estimate, using flux densities at {>=}24 {mu}m, indicates z{sub phot} = 3.19{sup +0.26}{sub -0.35}, consistent with the protocluster redshift. We then model the near-to-mid-infrared spectral energy distribution (SED) of SSA22-AzTEC1, and find that the SED modeling requires a large extinction (A{sub V} {approx} 3.4 mag) of starlight from a stellar component with M{sub star} {approx} 10{sup 10.9} M{sub sun}, assuming z = 3.1. Additionally, we find a significant X-ray counterpart with a very hard spectrum ({Gamma}{sub eff} = -0.34{sup +0.57}{sub -0.61}), strongly suggesting that SSA22-AzTEC1 harbors a luminous active galactic nuclei (AGNs; L{sub X} {approx} 3 x 10{sup 44} erg s{sup -1}) behind a large hydrogen column (N{sub H} {approx} 10{sup 24} cm{sup -2}). The AGN, however, is responsible for only {approx}10% of the bolometric luminosity of the host galaxy, and therefore the star formation activity likely dominates the submillimeter emission. It is possible that SSA22-AzTEC1 is the first example of a protoquasar growing at the bottom of the gravitational potential underlying the SSA22 protocluster.

Tamura, Y.; Iono, D.; Hatsukade, B.; Kawabe, R. [Nobeyama Radio Observatory, National Astronomical Observatory of Japan, Nobeyama, Minamimaki, Minamisaku, Nagano 384-1305 (Japan); Wilner, D. J.; Chung, A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Kajisawa, M.; Hayashino, T.; Ichikawa, T. [Astronomical Institute, Tohoku University, Aramaki, Aoba, Sendai, Miyagi 980-8578 (Japan); Uchimoto, Y. K.; Ikarashi, S.; Kohno, K. [Institute of Astronomy, University of Tokyo, Osawa, Mitaka, Tokyo 181-0015 (Japan); Alexander, D. M.; Lehmer, B. D.; Matsuda, Y. [Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Ezawa, H.; Nakanishi, K.; Takata, T. [National Astronomical Observatory of Japan, Osawa, Mitaka, Tokyo 181-8588 (Japan); Hughes, D. H. [Instituto Nacional de Astrofisica, Optica y Electronica, Aptdo. Postal 51 y 216, 72000 Puebla (Mexico); Wilson, G. W., E-mail: yoichi.tamura@nao.ac.j [Department of Astronomy, University of Massachusetts, 710 North Pleasant Street, Amherst, MA 01003 (United States)

2010-12-01

429

Estimate of the Distribution of Solids Within Mixed Hanford Double-Shell Tank AZ-101: Implications for AY-102  

SciTech Connect

This paper describes the current level of understanding of the suspension of solids in Hanford double-shell waste tanks while being mixed with the baseline configuration of two 300-horsepower mixer pumps. A mixer pump test conducted in Tank AZ-101 during fiscal year 2000 provided the basis for this understanding. Information gaps must be filled to demonstrate the capability of the baseline feed delivery system to effectively mix, sample, and deliver double-shell tank waste to the Hanford Tank Waste Treatment and Immobilization Plant (WTP) for vitrification.

Wells, Beric E.; Ressler, Jennifer J.

2009-04-29

430

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.

431

Freedomship: City At Sea  

NSDL National Science Digital Library

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

2002-01-01

432

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.

433

Building Healthy Cities  

Microsoft Academic Search

This chapter has reviewed the range of laws and government policies that affect the physical form of our cities. These laws\\u000a and policies include mandates and prohibitions, incentives and subsidies, and direct government involvement, and they touch\\u000a a broad range of issues including transportation, housing, schools, parks, and economic development. The chapter highlights\\u000a that the health of urban residents is

Wendy C. Perdue

434

Starbucks in Forbidden City  

Microsoft Academic Search

“Do you have plans to open stores in the Taj Mahal, Versailles, or Buckingham Palace?” China Central Television’s news anchor Rui Chenggang askedJim Donald, Starbucks Chairman and CEO at the June 2006 Yale CEO Leadership Summit. Just over six months later, on 12 January 2007 Rui posted a blog entry protesting against Starbucks’ presence in Beijing’s Forbidden City. Rui stated,

Michael Netzley; Bhatt Dev SO DIGANTRAI; Desmond Yi Ming WONG; Weilin Ursula Laura TAN; Yen Julia HEE

2011-01-01

435

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

PubMed Central

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

Martinez-Romero, Esperanza

2012-01-01

436

Raleigh: A Capital City  

NSDL National Science Digital Library

The story of the United States is told in many different ways, and the National Park Service's National Register of Historic Places offers a number of compelling online tours that allow visitors entry into many of the historic sites scattered around the country. This very nice online tour focuses on Raleigh, N.C., and was commissioned in partnership with the City of Raleigh and a number of related units of government. The tour presented on this site highlights 48 historic places, and includes the city's Victorian neighborhoods and some of the more quotidian commercial buildings around the area. Visitors can navigate these sites through a series of interactive maps, or by a comprehensive list that provides information about the historical significance of each structure or feature of the built environment. The site also contains a number of thematic essays that deal with different stages of the city's development, such as suburbanization. The site is rounded out by a selection of additional links to other online resources on Raleigh history and tourism, along with a select bibliography of relevant works.

437

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

NASA Astrophysics Data System (ADS)

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

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

2013-10-01

438

Conduit changes and eruptive styles at Red Mountain cinder cone, AZ, USA  

NASA Astrophysics Data System (ADS)

Red Mountain volcano is a Pleistocene (ca. 740 ky) cinder cone north of Flagstaff, AZ, in the northern Mio- Recent San Francisco volcanic field. Red Mountain erupted onto Permian sedimentary rocks with low topographic relief, likely covered in some places by older flows. The cone evolved through several stages that erupted and emplaced cinder, lava flow, agglutinate, and clastogenic lava. The transition from cinder eruption to mild hawaiian-type fountaining is contrary to observed activity at cinder cones, but may provide insight into conduit processes during basaltic eruptions. Earliest strombolian eruptions built a cone as much as 400 m high. Agglutinate is a relatively minor constituent as are vulcanian bombs < 1 m in diameter. Near the end of strombolian eruptions lava flowed from the base of the cone, primarily toward the west. Continued lava flow caused rafting of ~15% of the cone, including the vent area. Eruptions transitioned to mild hawaiian, with agglutinate emplacement, lava flow, clastogenic flow, and minor scoria eruption. Agglutinate at 200-350 m on the inner face of the rafted cone suggests a relatively low fountain height. Successions up to 30 m thick 4 km from vent expose interbedded welded cinder, agglutinate, clastogenic flow, and rooted lava flow. Activity at Red Mountain transitioned from strombolian to mild hawaiian, in opposition to most cinder cones. Hawaiian activity is generally attributed to a higher rate of magma flux than strombolian. Some change in the conduit clearly occurred causing either an increase in flux rate and/or a significant change in the vesiculation depth below the vent. We suggest two possibilities: 1) the rafting collapse of the cone, which decreased the conduit length by as much as 350 m, caused a significant change in the pressure profile, which in turn affected both the onset of bubble nucleation and the path length for bubble coalescence. This in turn caused less bubble/melt segregation and steadier (mild hawaiian) eruption. 2) A sudden increase in magma flux may have caused instability and collapse of the cone, with concomitant change in eruptive style.

Riggs, N. R.; Duffield, W. A.; Cashman, K. V.; Zimmer, B. W.

2006-12-01

439

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

PubMed

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

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

2013-05-16

440

Darkening effect on AZ31B magnesium alloy surface induced by nanosecond pulse Nd:YAG laser  

NASA Astrophysics Data System (ADS)

Permanent darkening effect was achieved on surface of AZ31B Mg alloy irradiated with nanosecond pulse Nd:YAG laser, and special attention was made to examine how surface structure as well as oxidation affect the darkening effect. Experiments were carried out to characterize morphological evolution and chemical composition of the irradiated areas by optical reflection spectrometer, Talysurf surface profiler, SEM, EDS, and XPS. The darkening effect was found to be occurred at the surface under high laser energy. Optical spectra showed that the induced darkening surface was uniform over the spectral range from 200 nm to 1100 nm. SEM and surface profiler showed that surface morphology of darkening areas consisted of large number of micron scale cauliflower-like clusters and protruding particles. EDS and XPS showed that compared to non-irradiated area, oxygen content at the darkening areas increased significantly. It was proposed a mechanism that involved trapping of light in the surface morphology and chemistry variation of irradiated areas to explain the laser-induced darkening effect on AZ31B Mg alloy.

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

2013-09-01

441

Microstructure Formation and Mechanical Properties of AZ31 Magnesium Alloy Solidified with a Novel Mechanical Vibration Technique  

NASA Astrophysics Data System (ADS)

A novel mechanical vibration for refining microstructure is reported where vibration energy was directly exerted into a molten alloy by a vibrating horn, and the vibrating horn was melted during vibration. Effects of vibration intensity and melt superheat on the microstructure and mechanical properties of AZ31 magnesium alloy were investigated. It is confirmed that the melting of the vibrating horn could effectively extract the superheat and latent heat from the interior of the molten alloy, leading to rapid cooling during the initial stage of solidification, and the cooling rate is strongly dependent on the vibration acceleration and melt superheat. This study showed that it was difficult to refine the solidified microstructure when the treated alloy was kept in the full liquid state within the entire vibrating duration. A significantly refined microstructure was obtained by applying mechanical vibration during the nucleation stage, and a globular microstructure could form in a few seconds after solidification. When the molten alloy was treated from 920 K to 903 K (647 °C to 630 °C), with increasing vibration acceleration from 2.5 to 19 m s-2, the coarse dendritic microstructure of the produced AZ31 billets transformed into a well-refined, reasonably uniform, and non-dendritic one, and mechanical properties were improved significantly. Moreover, the mechanisms of microstructure formation are discussed.

Guo, H. M.; Zhang, A. S.; Yang, X. J.; Yan, M. M.; Ding, Y.

2013-09-01

442

Modeling the Stress-Strain Behavior and Hot Tearing during Direct Chill Casting of an AZ31 Magnesium Billet  

NASA Astrophysics Data System (ADS)

Quantitative knowledge of the thermal mechanical history experienced during direct chill (DC) casting aids the scientific understanding of the process especially in terms of defect formation such as hot tearing. In this work, a thermomechanical finite element (FE) model has been developed to simulate the DC casting of magnesium alloy AZ31 billets. The mathematical model simulates the evolution of temperature, stress, and strain within the billet during an industrial DC casting process. These quantities were then used to calculate the evolution in pressure, and hence hot tearing tendency, within the semisolid regime via the Rappaz-Drezet-Gremaud (RDG) criterion. The temperature predictions were validated against experimental thermocouple data measured during a plant trial at an industrial magnesium DC casting facility. In addition, the residual elastic strains predicted by the model were compared to residual strain measurements made at the Canadian Neutron Beam Centre (CNBC) using a magnesium billet produced during the industrial casting trial. The validated model was then used to quantitatively assess the impact of casting speed on the hot tearing tendency in AZ31 billets.

Hao, H.; Maijer, D. M.; Wells, M. A.; Phillion, Andre; Cockcroft, S. L.

2010-08-01

443

Mechanical Properties of AZ31 Magnesium Alloy Under Severe Plastic Deformation Through Rolling and Heat Treatment Affects  

NASA Astrophysics Data System (ADS)

AZ31 Magnesium alloy is a light alloy consisting of 96 wt% magnesium, 3 wt% aluminum, and 1 wt% zinc that is 34% lighter than aluminum with fairly good strength and other properties. However, the ductility is poor due to its HCP structure that does not satisfy the Taylor Criterion for independent slip planes. Research into how to improve the strength and ductility through plastic deformation was conducted at University of Nevada in Reno. Different sizes of AZ31B were received from a Chinese magnesium company. Each size went through severe plastic deformation by rolling at different temperatures. Most of the sample went through annealing at different temperatures for different times. The mechanical properties and microstructure of each sample were collected. These samples were compared to one another with the control samples to determine any effects from the severe plastic deformation and/or heat treatment affects. From the analysis of the data collected, there was a correlation between the mechanical properties, annealing temperature, and annealing time. The mechanical properties were higher at lower annealing temperatures than at the higher annealing temperatures. In addition, there was a drastic increase in all mechanical properties between 3 and 5 hours of annealing for an unknown reason. Precipitates are seen within the microstructure of some of the samples. Most of the microstructures showed equiaxed grains throughout the majority of the samples. The grains that were not equiaxed showed elongation due to the extrusion process and possibly from the rolling process.

Busch, Eric Michael

444

BIG CITY, BIG TURNOUT? ELECTORAL PARTICIPATION IN AMERICAN CITIES  

Microsoft Academic Search

This article seeks to describe and explain variation in voter turnout in American big city municipal elections using data from 332 mayoral elections in 38 large U.S. cities over 25 years. In my cross-sectional time-series analysis of turnout in mayoral elections, I find that city- level demographic factors are only weakly correlated with turnout. By contrast, institutional and campaign factors

NEAL CAREN

2007-01-01

445

Living in living cities.  

PubMed

Abstract This article presents an overview of current and potential applications of living technology to some urban problems. Living technology can be described as technology that exhibits the core features of living systems. These features can be useful to solve dynamic problems. In particular, urban problems concerning mobility, logistics, telecommunications, governance, safety, sustainability, and society and culture are presented, and solutions involving living technology are reviewed. A methodology for developing living technology is mentioned, and supraoptimal public transportation systems are used as a case study to illustrate the benefits of urban living technology. Finally, the usefulness of describing cities as living systems is discussed. PMID:23834590

Gershenson, Carlos

2013-07-08

446

CityGML - Interoperable semantic 3D city models  

NASA Astrophysics Data System (ADS)

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

Gröger, Gerhard; Plümer, Lutz

2012-07-01

447

Visualizing Software Systems as Cities  

Microsoft Academic Search

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

Richard Wettel; Michele Lanza

2007-01-01

448

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

PubMed Central

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

2013-01-01

449

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

Microsoft Academic Search

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

Liming Liu; Gang Song; Guoli Liang; Jifeng Wang

2005-01-01

450

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

Microsoft Academic Search

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

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

2009-01-01

451

The Undersea and Hyperbaric Medical Society. A report on the annual scientific meeting 2012, Phoenix, AZ, USA June 21-23.  

PubMed

This is a report on the content of the 45th annual scientific meeting of the Undersea and Hyperbaric Medical Society (UHMS) in Phoenix AZ, USA last June 21-23, 2012. The UHMS is the major representative body for both physicians and scientists in diving and hyperbaric physiology and medicine. PMID:23849179

Bennett, Michael H

2012-12-01

452

Vane jövÅ‘je az agrárgazdaságtannak mint önálló tudománynak?  

Microsoft Academic Search

Az agrárgazdaságtannal foglalkozók mint tudományos közösség előtt komoly kihívások állnak. Az elmúlt évtizedekben a hagyományos agrárgazdaságtan művelésének külső és belső feltételei gyökeresen megváltoztak. Ezek közül talán a legjelentősebb, hogy az agrárgazdaságtan mint szakma iránti kereslet csökkenésével, illetve a kereslet szerkezetének megváltozásával a szakma „láthatósága†is visszaesett, melynek legfontosabb jelei a tanszékek számának zsugorodása, illetve a stagnáló tudományos társasági élet. Az

Imre Ferto

2011-01-01

453

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

SciTech Connect

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

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

2010-06-15

454

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

PubMed

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

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

2013-05-02

455

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

Microsoft Academic Search

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

Jimmy X. Jia; Guangling Song; Andrej Atrens

2005-01-01

456

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

SciTech Connect

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

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

2009-08-05

457

Structure–property quantification of corrosion pitting under immersion and salt-spray environments on an extruded AZ61 magnesium alloy  

Microsoft Academic Search

Extruded AZ61 magnesium coupons were exposed to immersion and cyclical salt spray environments over 60h in order to characterize their corrosion rates. The characteristics of general corrosion, pitting corrosion, and intergranular corrosion were quantified at various intervals. General corrosion was more prevalent on the immersion surface. In addition, more pits formed on the immersion surface due the continuous exposure to

Holly J. Martin; M. F. Horstemeyer; Paul T. Wang

2011-01-01

458

Independence City Tavern National Historical Park, Pennsylvania: City Tavern.  

National Technical Information Service (NTIS)

City Tavern flourished from 1774 until 1800 as one of the most important public houses in Philadelphia. It functioned as a social, political, even business center for this busy city. Although it had been destroyed, the National Park Service at Independenc...

C. V. Hershey

1974-01-01

459

Smart cities of the future  

NASA Astrophysics Data System (ADS)

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

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

2012-11-01

460

Safe in the city.  

PubMed

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

Anderson, Norma R

2008-10-01

461

Kansas City Hopewell  

NSDL National Science Digital Library

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

462

Kid-Friendly Cities Report Card, 2001.  

ERIC Educational Resources Information Center

|This report examines the health and wellbeing of children in the United States' largest cities, covering every city with a population of 100,000 or more, as well as the largest cities in states without any cities of this size. Research shows that many cities are becoming more child-friendly, with better access to good education, jobs, and health…

Polansky, Lee S., Ed.

2001-01-01

463

Kid-Friendly Cities Report Card, 2001.  

ERIC Educational Resources Information Center

This report examines the health and wellbeing of children in the United States' largest cities, covering every city with a population of 100,000 or more, as well as the largest cities in states without any cities of this size. Research shows that many cities are becoming more child-friendly, with better access to good education, jobs, and health…

Polansky, Lee S., Ed.

2001-01-01

464

AzTEC/ASTE Deep and Wide Submillimeter Galaxy Survey in the Subaru/XMM-Newton Deep Field: Identification of VLA, Spitzer and Herschel Counterparts to 1100-?m-Selected Galaxies and Redshifts  

NASA Astrophysics Data System (ADS)

We present results of our AzTEC/ASTE submillimeter galaxies (SMGs) survey in the Subaru/XMM-Newton Deep Field (SXDF), and VLA (21 cm), Spitzer (3.6-8 ?m and 24 ?m) and Herschel (100 and 160 ?m) counterpart identifications for 1100-?m-selected SMGs. We obtained a 1100-?m map of ˜ 1200 arcmin2 with the rms noise level of ˜ 0.5 mJy (1 ?). Our AzTEC map achieved new detections of 281 sources (S/N ? 3.5 ?). For 221 of 281 AzTEC sources, we searched counterparts in order to obtain multi-wavelength data. Deep Herschel PACS 100-?m and 160-?m images cover the whole of the AzTEC map, and 34 of 221 (= 15 %) and 54 of 221 (= 24 %)AzTEC sources have PACS 100-?m and 160-?m counterparts, respectively. We found VLA radio and/or MIPS 24-?m robust (with a significance of ? 95 %) counterparts to 102 of 221 the AzTEC SMGs. In addition to this, we have developed an improved identification method using IRAC data (3.6-8 ?m) and their colors, in order to cover the AzTEC SMGs located at higher redshift such as z > 3, which is inaccessible with the existing VLA, MIPS and Herschel data alone. With this method, we have achieved another robust detections of 20 IRAC counterparts to AzTEC sources. 131 of 221 AzTEC sources have at least one robust counterparts, and 23 of 221 have more than two robust counterparts. Including tentative identifications (with a significance of ? 90 %), 171 of 221 (= 78 %) 1100-?m-selected SMGs have counterparts. We estimated photometric redshifts of the counterparts using deep near-, and med-infrared and optical data, providing zmedian of 2.2. Among them, we found that there were some 1100-?m sources faint in multi-bands data suggesting the extremely high redshift.

Ikarashi, S.; Kohno, K.; Aretxaga, I.; Arumugam, V.; Caputi, K.; Dunlop, J.; Hatsukade, B.; Hughes, D.; Iono, D.; Ivison, R.; Kawabe, R.; Motohara, K.; Nakanishi, K.; Ohta, K.; Suzuki, K.; Tamura, Y.; Umehata, H.; Wilson, G.; Yabe, K.; Yun, M.

2013-10-01

465

Fantasies of domesti(city)  

Microsoft Academic Search

The conjunction of the terms 'city' and 'house' provides an extraordinary link between these three quotations from paradigmatic texts of radically different historical locations. The house and the city arguably occupy two extreme ends of the architectural scale and the modernist imagination has placed them at the opposite ends of the private\\/public divide. Home is constructed as the mythologised space

Gülsüm Baydar Nalbanto?lu; Leone Batisti Alberti; Le Corbusier

2000-01-01

466

Globalization: Countries, Cities and Multinationals  

Microsoft Academic Search

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

Philip McCann; Zoltan J. Acs

2011-01-01

467

Pollution Parameters in Asian Cities  

Microsoft Academic Search

Cities are the core of environmental problems. One such problem is air pollution, a diseconomy of urban areas. Although the majority of the population identifies air pollution with the advent of the industrial revolution, such problems have been plaguing cities around the globe for centuries. Air pollution does not emanate only from local sources. The atmosphere has no borders and

JOHN E. BENHART

468

Locating cities on global circuits  

Microsoft Academic Search

This paper discusses the cities that have the resources which enable firms and markets to be global. It considers the new intensity and complexity of globally-connected systems of production, finance and management which may disperse production, yet need (relatively few) networks of cities to provide their organizational and management architecture. This produces new geographies and hierarchies of centrality - particular

Saskia Sassen

2002-01-01

469

Designing an Ecologically Sound City  

NSDL National Science Digital Library

This lesson is intended to make students aware of the need to respect their environment and its natural resources. They will apply that knowledge in developing an "ecologically sound" city. Using an outline, they will design a city that has ecological laws, power source(s) for lights and heat, a river, two industries, and homes for its population.

1998-01-01

470

Aerial view of a city  

NSDL National Science Digital Library

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

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

2007-01-12

471

House prices and city revenues  

Microsoft Academic Search

Very little is known about what impact recent large upward and downward swings in single-family home values have had on local government budgets. Using a unique 15-year panel of Florida cities that includes both detailed revenue and house price data, we investigate the pathways whereby a change in house price may affect city revenue per capita and test for symmetric

William M. Doerner; Keith R. Ihlanfeldt

2011-01-01

472

The Future of American Cities.  

ERIC Educational Resources Information Center

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

Mulhern, John J., Ed.

473

Cultural development and city neighborhoods  

Microsoft Academic Search

This article examines four defining characteristics of city cultural policy: (1) the concentration of cultural resources in downtowns and cultural districts; (2) a policy infrastructure focused on nonprofit organizations, cultural industries and tourism; (3) the narrow policy scope and political influence of city-level cultural agencies; and (4) the decentralized and under-institutionalized authority and oversight in the public cultural sector. The

Carole Rosenstein

2011-01-01

474

CHED Events: Salt Lake City  

NASA Astrophysics Data System (ADS)

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

Wink, Donald J.

2009-03-01

475

Project Wish: The Emerald City.  

National Technical Information Service (NTIS)

Phase 3 of Project WISH saw the evolution of the Emerald City (E-City) from a collection of specialized independent analyses and ideas to a working structural design integrated with major support systems and analyses. Emphasis was placed on comparing and ...

H. Oz J. Dunne S. Butchar T. George R. Hellstrom

1992-01-01

476

Educating cities in Latin America  

NASA Astrophysics Data System (ADS)

This article considers the development of educating cities from a political perspective, illustrating in detail the diversity of organisations and individuals involved and the challenges they are facing. Bearing in mind that educating cities were established from the 1990s onwards in Europe and spread to other continents from there, the purpose of this article is to demonstrate how this proposal was adopted in Latin America. After discussing the basic aims of educating cities, the paper focuses on the Latin American experience, giving examples of existing projects within the educating cities initiative. The authors are particularly interested in the contrast between the political intentions of educating cities on the one hand and the social, economic, political and cultural world on the other hand. They observe that in this context there is a danger of the individual being forgotten, which contradicts the actual intention of the educating city concept. They also discuss the problem of who should carry out the realisation of educating cities and how the various stakeholders might coordinate their actions. Contemplating new directions at the end of their paper, the authors sum up a number of guidelines and offer recommendations for action in developing educating cities.

Messina, Graciela; Valdés-Cotera, Raúl

2013-09-01

477

Knowledge Infrastructures for Solar Cities  

ERIC Educational Resources Information Center

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

Vanderburg, Willem H.

2006-01-01

478

Effect of the Pulse Duty Cycle on Characteristics of Plasma Electrolytic Oxidation Coatings Formed on AZ31 Magnesium Alloy  

NASA Astrophysics Data System (ADS)

Ceramic coatings are synthesized on AZ31 magnesium alloy in alkaline silicate solution by the method of plasma electrolytic oxidation. The effect of two different duty cycles (10% and 50%) on the structure and corrosive properties of the coatings is investigated. It is found that the coatings are mainly composed of MgO, Mg2SiO4 and MgF2 through XRD analysis. SEM images indicate that coatings formed at 50% duty cycle have a relatively coarse surface with larger pore size and fewer pores, and have a slower growth rate than those formed at 10% duty cycle with the same treatment time. However, the results of potentiodynamic polarization tests demonstrate that coatings formed at 50% duty cycle exhibit better corrosion resistance as a result of more compact microstructure.

Chen, Huan; Lv, Guo-Hua; Zhang, Gu-Ling; Pang, Hua; Wang, Xing-Quan; Zhang, You-Wei; Lee, Heon-Ju; Yang, Si-Ze

2009-09-01

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Abnormal macropore formation during double-sided gas tungsten arc welding of magnesium AZ91D alloy  

SciTech Connect

One of the major concerns during gas tungsten arc (GTA) welding of cast magnesium alloys is the presence of large macroporosity in weldments, normally thought to occur from the presence of gas in the castings. In this study, a double-sided GTA welding process was adopted to join wrought magnesium AZ91D alloy plates. Micropores were formed in the weld zone of the first side that was welded, due to precipitation of H{sub 2} as the mushy zone freezes. When the reverse side was welded, the heat generated caused the mushy zone in the initial weld to reform. The micropores in the initial weld then coalesced and expanded to form macropores by means of gas expansion through small holes that are present at the grain boundaries in the partially melted zone. Macropores in the partially melted zone increase with increased heat input, so that when a filler metal is used the macropores are smaller in number and in size.

Shen Jun [College of Mechanical Engineering, Chongqing University, Chongqing 400044 (China)], E-mail: shenjun2626@163.com; You Guoqiang; Long Siyuan [College of Mechanical Engineering, Chongqing University, Chongqing 400044 (China); Pan Fusheng [College of Material Science and Engineering, Chongqing University, Chongqing 400044 (China)

2008-08-15