The AFHSC-Division of GEIS Operations Predictive Surveillance Program: A Multidisciplinary Approach for the Early Detection and Response to Disease Outbreaks

DTIC Science & Technology

2011-01-01

borne hantavirus diseases. In Kenya, USAMRU-K discovered hantaviruses in live rodents from Marigat and Garissa (Figure 15). These viruses are now...1Armed Forces Health Surveillance Center, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA Full list of author information is available at the end...6. AUTHOR (S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Armed Forces Health

76 FR 19188 - Joint Biomedical Laboratory Research and Development and Clinical Science Research and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-06

.../Silver Spring. Neurobiology-E June 3, 2011 Crowne Plaza DC/Silver Spring. Pulmonary Medicine June 3, 2011 Crowne Plaza DC/Silver Spring. Cellular & Molecular Medicine........ June 6, 2011 Crowne Plaza DC/Silver...

Photocopy of original blackandwhite silver gelatin print, WEST END OF ...

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

Photocopy of original black-and-white silver gelatin print, WEST END OF PENNSYLVANIA AVENUE ELL SHOWING TEMPORARY BRICK WALL, March 1, 1935, photographer Reni - Internal Revenue Service Headquarters Building, 1111 Constitution Avenue Northwest, Washington, District of Columbia, DC

Photocopy of original blackandwhite silver gelatin print, WEST END OF ...

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

Photocopy of original black-and-white silver gelatin print, WEST END OF PENNSYLVANIA AVENUE ELL SHOWING TEMPORARY BRICK WALL, May 1, 1935, photographer Reni - Internal Revenue Service Headquarters Building, 1111 Constitution Avenue Northwest, Washington, District of Columbia, DC

Primary producers and nutrient loading in Silver Springs, FL, USA

EPA Science Inventory

The characteristics and dynamics of primary producer communities of Silver Springs was examined to compare with that observed by Odum as a means of evaulating the impacts of changes that have occurred over time. The Silver Springs ecosystem is considered an ecosystem at risk, whe...

Comparison of Estimated Areas Contributing Recharge to Selected Springs in North-Central Florida by Using Multiple Ground-Water Flow Models

USGS Publications Warehouse

Shoemaker, W. Barclay; O'Reilly, Andrew M.; Sepúlveda, Nicasio; Williams, Stanley A.; Motz, Louis H.; Sun, Qing

2004-01-01

Areas contributing recharge to springs are defined in this report as the land-surface area wherein water entering the ground-water system at the water table eventually discharges to a spring. These areas were delineated for Blue Spring, Silver Springs, Alexander Springs, and Silver Glen Springs in north-central Florida using four regional ground-water flow models and particle tracking. As expected, different models predicted different areas contributing recharge. In general, the differences were due to different hydrologic stresses, subsurface permeability properties, and boundary conditions that were used to calibrate each model, all of which are considered to be equally feasible because each model matched its respective calibration data reasonably well. To evaluate the agreement of the models and to summarize results, areas contributing recharge to springs from each model were combined into composite areas. During 1993-98, the composite areas contributing recharge to Blue Spring, Silver Springs, Alexander Springs, and Silver Glen Springs were about 130, 730, 110, and 120 square miles, respectively. The composite areas for all springs remained about the same when using projected 2020 ground-water withdrawals.

Hydrology, Water Quality, and Aquatic Communities of Selected Springs in the St. Johns River Water Management District, Florida

USGS Publications Warehouse

Walsh, Stephen J.; Knowles, Leel; Katz, Brian G.; Strom, Douglas G.

2009-01-01

Hydrologic, physicochemical, and aquatic community data were collected and compiled by the U.S. Geological Survey for selected springs within the St. Johns River Water Management District from January 2004 to October 2007. Nine springs were included in this study: Alexander, Apopka, Bugg, De Leon, Gemini, Green, Rock, Silver Glen, and Wekiwa. Urban lands increased in Alexander, Apopka, De Leon, Gemini, Green, and Wekiwa springsheds between 1973 and 2004, accompanied by a loss of forested and/or agricultural lands in most springsheds. Forested cover increased and open surface waters and wetlands decreased in the Bugg and Rock springsheds. Although rainfall did not change significantly over time in each springshed, spring discharge decreased significantly in De Leon, Fern Hammock, Rock, Silver, and Wekiwa Springs. Nitrate concentrations increased significantly with time in Apopka, Fern Hammock, Gemini Springs run, and Juniper Springs, and decreased significantly in Alexander Spring, Bugg Spring run, Rock Springs, and Wekiwa Springs. Phosphorus increased significantly with time in Juniper Springs and decreased significantly in Apopka, De Leon, Rock, Silver Glen, and Wekiwa Springs. Benthic macroinvertebrate communities ranged from relatively low diversity assemblages (Green Spring) to assemblages with high taxonomic richness, diversity, and dominance (Rock and De Leon Springs). Shannon-Wiener diversity index averages among samples pooled by spring were lowest for Apopka Spring and greatest for Rock, Bugg, and Silver Glen Springs. Mean Stream Condition Index for pooled samples per spring was lowest for De Leon and Gemini Springs and highest for Rock and Wekiwa Springs. Mean percentages of very tolerant taxa were lowest for Alexander Spring and highest for Bugg and Green Springs. Fish community richness was lowest for Green Spring, and greatest for Alexander Spring run and Silver Glen Springs. Forty five fish species representing 35 genera and 23 families were collected or observed from all springs in this study. Samples were dominated by centrarchids, cyprinids, fundulids, atherinopsids, and poeciliids.

Washington, D.C.'s vanishing springs and waterways

USGS Publications Warehouse

Williams, Garnett P.

1977-01-01

This paper traces the disappearance or reduction of the many prominent springs and waterways that existed in Washington, D.C. , 200 years ago. The best known springs were the Smith Springs (now under the McMillan Reservoir), the Franklin Park Springs (13th and I Streets, NW.), Gibson 's Spring (15th and E Streets, NE.), Caffrey 's Spring (Ninth and F Streets, NW.), and the City Spring (C Street between Four and One-Half and Sixth Streets, NW.). Tiber Creek, flowing south to the Capitol and thence westward along Consititution Avenue, joined the Potomac River at 17th Street and Constitution Avenue. In the 1800's, the Constitution Avenue reach was made into a canal which was used by scows and steamboats up to about 1850. The canal was changed into a covered sewer in the 1870's, and the only remaining visible surface remnant is the lock-keeper 's little stone house at 17th and Constitution Avenue, NW. Because of sedimentation problems and reclamation projects, Rock Creek, the Potomac River , and the Anacostia River are considerably narrower and shallower today than they were in colonial times. For example, the mouth of Rock Creek at one time was a wide, busy ship harbor , which Georgetown used for an extensive foreign trade, and the Potomac River shore originally extended to 17th and Constitution Avenue, NW. (Woodard-USGS)

Diagnostic Approach to Acute Diarrheal Illness in a Military Population on Training Exercises in Thailand, a Region of Campylobacter Hyperendemicity

DTIC Science & Technology

2008-04-01

Center (Silver Spring, MD) and the Armed Forces Research Institute FIG. 1. Posttest probability of Campylobacter-associated illness based on the...Sanders5 Enteric Diseases Department, Naval Medical Research Center, Silver Spring, Maryland1; Armed Forces Research Institute of Medical Sciences, Bangkok...Thailand2; Walter Reed Army Institute of Research , Silver Spring, Maryland3; Naval Environmental Preventive Medicine Unit 6, Pearl Harbor, Hawaii4

Inquiries-HDSC/OWP

Science.gov Websites

/Office of Water Prediction 1325 East-West Highway, W/OWP Silver Spring, MD 20910-3283 Main Link Weather Service Office of Water Prediction (OWP) 1325 East West Highway Silver Spring, MD 20910 Page

77 FR 1939 - National Institute of Allergy and Infectious Diseases; Notice of Closed Meetings

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-12

...: To review and evaluate grant applications. Place: Crowne Plaza Washington DC-Silver Spring, Silver Spring, MD 20910. Contact Person: B. Duane Price, Ph.D., Scientific Review Officer, Scientific Review...

Make Development Decisions Predictable and Fair: Green Tape Program, Silver Spring, Maryland

EPA Pesticide Factsheets

Montgomery County's Green Tape program is making redevelopment in Silver Spring, Maryland, faster and more cost effective by speeding the permitting process for development in the mixed-use city center.

OHD - Dis_Svy: Red River Flood 97

Science.gov Websites

Weather Building 1325 East-West Highway Silver Spring, Maryland 20910 (301) 713-1658 docsmsh.gif (2446 National Weather Service Office of Hydrologic Development 1325 East West Highway Silver Spring, MD 20910

21 CFR 807.37 - Inspection of establishment registration and device listings.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Hampshire Ave., Bldg. 66, rm. 3521, Silver Spring, MD 20993-0002. In addition, there will be available for.... 66, rm. 3521, Silver Spring, MD 20993-0002. (3) Requests for device listing information not...

Media Contacts - Public Affairs - NOAA's National Weather Service

Science.gov Websites

Service Headquarters - Silver Spring, Md. Eastern Region - Bohemia N.Y. Main phone number, (301) 713-0622 National Weather Service 1325 East-West Highway Silver Spring, MD 20910 Page Author: NWS Internet Services

National Weather Service - Strategic Planning and Policy

Science.gov Websites

Highway Silver Spring, MD 20910-3283 Phone: (301) 713-0258; Fax: (301) 713-1239 NWS Homepage, FAQs Strategic Planning and Policy Office 1325 East West Highway Silver Spring, MD 20910 Page last modified

National Weather Service - Strategic Planning and Policy

Science.gov Websites

Policy ATTN: W/SP 1325 East-West Highway Silver Spring, MD 20910-3283 Phone: (301) 713-0258; Fax: (301 Administration National Weather Service Strategic Planning and Policy Office 1325 East West Highway Silver Spring

Characterization of the hydrology, water chemistry, and aquatic communities of selected springs in the St. Johns River Water Management District, Florida, 2004

USGS Publications Warehouse

Phelps, G.G.; Walsh, Stephen J.; Gerwig, Robert M.; Tate, William B.

2006-01-01

The hydrology, water chemistry, and aquatic communities of Silver Springs, De Leon Spring, Gemini Springs, and Green Spring in the St. Johns River Water Management District, Florida, were studied in 2004 to provide a better understanding of each spring and to compile data of potential use in future water-management decisions. Ground water that discharges from these and other north-central Florida springs originates from the Upper Floridan aquifer of the Floridan aquifer system, a karstic limestone aquifer that extends throughout most of the State's peninsula. This report summarizes data about flow, water chemistry, and aquatic communities, including benthic invertebrates, fishes, algae, and aquatic macrophytes collected by the U.S. Geological Survey, the St. Johns River Water Management District, and the Florida Department of Environmental Protection during 2004, as well as some previously collected data. Differences in water chemistry among these springs reflect local differences in water chemistry in the Upper Floridan aquifer. The three major springs sampled at the Silver Springs group (the Main Spring, Blue Grotto, and the Abyss) have similar proportions of cations and anions but vary in nitrate and dissolved oxygen concentrations. Water from Gemini Springs and Green Spring has higher proportions of sodium and chloride than the Silver Springs group. Water from De Leon Spring also has higher proportions of sodium and chloride than the Silver Springs group but lower proportions of calcium and bicarbonate. Nitrate concentrations have increased over the period of record at all of the springs except Green Spring. Compounds commonly found in wastewater were found in all the springs sampled. The most commonly detected compound was the insect repellant N,N'-diethyl-methyl-toluamide (DEET), which was found in all the springs sampled except De Leon Spring. The pesticide atrazine and its degradate 2-chloro-4-isopropylamino-6-amino-s-triazine (CIAT) were detected in water from the Silver Springs group and in both boils at Gemini Springs. No pesticides were detected in water samples from De Leon Spring and Green Spring. Evidence of denitrification was indicated by the presence of excess nitrogen gas in water samples from most of the springs. Aquatic communities varied among the springs. Large floating mats of cyanobacteria (blue-green algae), identified as Lyngbya wollei, were observed in De Leon Spring during all sampling events in 2004. At Gemini Springs, the dominant periphyton was Rhizoclonium sp. Of the three springs sampled for benthic invertebrates, De Leon Spring had the highest overall species richness and most disturbance intolerant species (Florida Index = 4). Green Spring had the lowest species richness of the springs sampled. Based on qualitative comparisons, overall macroinvertebrate species richness seemed to be negatively related to magnesium, potassium, sodium, and specific conductance. Invertebrate abundance was greatest when dissolved oxygen and nitrate were high but phosphorus and potassium concentrations were low. Dipteran abundance seemed to be positively associated with specific conductance and total organic carbon but negatively associated with nitrate-N. Amphipods were the numerically dominant group collected in most (six of nine) collections. Shifts in amphipod abundance of the two species collected (Gammarus sp. and Hyalella azteca) varied by season among the three springs, but there were no trends evident in the variation. Fish populations were relatively species-rich at the Silver Springs group, De Leon Spring, and Gemini Springs, but not at Green Spring. Nonindigenous fish species were observed at all springs except Green Spring.

Photocopy of original blackandwhite silver gelatin print, VIEW FROM WASHINGTON ...

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

Photocopy of original black-and-white silver gelatin print, VIEW FROM WASHINGTON MONUMENT, October 3, 1929, photography Commercial Photo - Internal Revenue Service Headquarters Building, 1111 Constitution Avenue Northwest, Washington, District of Columbia, DC

Photocopy of original blackandwhite silver gelatin print, C STREET FACADE, ...

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

Photocopy of original black-and-white silver gelatin print, C STREET FACADE, October 3, 1929, photographer Commercial Photo Company - Internal Revenue Service Headquarters Building, 1111 Constitution Avenue Northwest, Washington, District of Columbia, DC

21 CFR 203.12 - An appeal from an adverse decision by the district office.

Code of Federal Regulations, 2012 CFR

2012-04-01

..., 10903 New Hampshire Ave., Silver Spring, MD 20993-0002. An appeal from an adverse decision by the... and Research, Food and Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD 20993-0002...

21 CFR 203.12 - An appeal from an adverse decision by the district office.

Code of Federal Regulations, 2013 CFR

2013-04-01

..., 10903 New Hampshire Ave., Silver Spring, MD 20993-0002. An appeal from an adverse decision by the... and Research, Food and Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD 20993-0002...

21 CFR 203.12 - An appeal from an adverse decision by the district office.

Code of Federal Regulations, 2014 CFR

2014-04-01

..., 10903 New Hampshire Ave., Silver Spring, MD 20993-0002. An appeal from an adverse decision by the... and Research, Food and Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD 20993-0002...

Photocopy of original blackandwhite silver gelatin print, VIEW OF NORTH ...

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

Photocopy of original black-and-white silver gelatin print, VIEW OF NORTH WALL OF MAIN COURT, May 1, 1935, photographer Reni - Internal Revenue Service Headquarters Building, 1111 Constitution Avenue Northwest, Washington, District of Columbia, DC

Photocopy of original blackandwhite silver gelatin print, VIEW FROM SOUTHEAST ...

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

Photocopy of original black-and-white silver gelatin print, VIEW FROM SOUTHEAST CORNER, April 1, 1929, photographer Commercial Photo Company - Internal Revenue Service Headquarters Building, 1111 Constitution Avenue Northwest, Washington, District of Columbia, DC

Photocopy of original blackandwhite silver gelatin print, TWELFTH STREET DRIVEWAY ...

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

Photocopy of original black-and-white silver gelatin print, TWELFTH STREET DRIVEWAY ENTRANCE, August 31, 1929, photographer Commercial Photo Company - Internal Revenue Service Headquarters Building, 1111 Constitution Avenue Northwest, Washington, District of Columbia, DC

Photocopy of original blackandwhite silver gelatin print, C STREET AT ...

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

Photocopy of original black-and-white silver gelatin print, C STREET AT TWELFTH STREET, May 1, 1930, photographer Commercial Photo Company - Internal Revenue Service Headquarters Building, 1111 Constitution Avenue Northwest, Washington, District of Columbia, DC

Photocopy of original blackandwhite silver gelatin print, VIEW FROM JUSTICE ...

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

Photocopy of original black-and-white silver gelatin print, VIEW FROM JUSTICE BUILDING LOOKING WEST, June 4, 1934, photographer Reni - Internal Revenue Service Headquarters Building, 1111 Constitution Avenue Northwest, Washington, District of Columbia, DC

Photocopy of original blackandwhite silver gelatin print, VIEW FROM NORTHWEST ...

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

Photocopy of original black-and-white silver gelatin print, VIEW FROM NORTHWEST CORNER, April 1, 1929, photographer Commercial Photo Company - Internal Revenue Service Headquarters Building, 1111 Constitution Avenue Northwest, Washington, District of Columbia, DC

Photocopy of original blackandwhite silver gelatin print, LOOKING SOUTHEAST FOR ...

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

Photocopy of original black-and-white silver gelatin print, LOOKING SOUTHEAST FOR NORTHEAST CORNER OF WING, November 1, 1934, photographer Reni - Internal Revenue Service Headquarters Building, 1111 Constitution Avenue Northwest, Washington, District of Columbia, DC

Optimal design of stormwater basins with bio-sorption activated media (BAM) in karst environments - phase I : site screening and selection.

DOT National Transportation Integrated Search

2015-12-01

Anthropogenic activities within the Silver Springs springshed over recent decades may have contributed : to elevated nutrient concentrations in stormwater runoff and groundwater, leading to the eutrophication : of Silver Springs. To remove the nutrie...

77 FR 49450 - Issues in the Design of Clinical Trials of Antibacterial Drugs for the Treatment of Non-Cystic...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-16

...:30 p.m. Location: The public workshop will be held at the Sheraton Silver Spring Hotel, 8777 Georgia Ave., Silver Spring, MD 20910. The hotel's phone number is 301-589-0800. Seating is limited and...

Photocopy of original blackandwhite silver gelatin print, AERIAL VIEW OF ...

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

Photocopy of original black-and-white silver gelatin print, AERIAL VIEW OF FEDERAL TRIANGLE, IRS BUILDING EAST SIDE OF THE OLD POST OFFICE BUILDING, 1936, photographer unknown - Internal Revenue Service Headquarters Building, 1111 Constitution Avenue Northwest, Washington, District of Columbia, DC

76 FR 12847 - Change of Address; Requests for Exemption From the Bar Code Label Requirements

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-09

... INFORMATION CONTACT: Rikin Mehta, Center for Drug Evaluation and Research, Food and Drug Administration, 10903... and Research, Food and Drug Administration, 10903 New Hampshire Ave., Bldg. 51, Silver Spring, MD... Evaluation and Research, Food and Drug Administration, 10903 New Hampshire Ave., Bldg. 51, Silver Spring, MD...

77 FR 20025 - Draft Guidance for Industry on Compliance Policy for Reporting Drug Sample Distribution...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-03

... Research, Food and Drug Administration, 10903 New Hampshire Ave., Bldg. 51, Rm. 2201, Silver Spring, MD... Evaluation and Research (CBER), Food and Drug Administration, 1401 Rockville Pike, Suite 200N, Rockville, MD... Research, Food and Drug Administration, 10903 New Hampshire Ave., Bldg. 51, Rm. 4288, Silver Spring, MD...

Impact electrochemistry on screen-printed electrodes for the detection of monodispersed silver nanoparticles of sizes 10-107 nm.

PubMed

Nasir, Muhammad Zafir Mohamad; Pumera, Martin

2016-10-12

Impact electrochemistry provides a useful alternative technique for the detection of silver nanoparticles in solutions. The combined use of impact electrochemistry on screen-printed electrodes (SPEs) for the successful detection of silver nanoparticles provides an avenue for future on-site, point-of-care detection devices to be made for environmental, medicinal and biological uses. Here we discuss the use of screen-printed electrodes for the detection of well-defined monodispersed silver nanoparticles of sizes 10, 20, 40, 80, and 107 nm.

19. VIEW OF THE PLATING BATHS AND CONTROL PANELS. GOLD ...

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

19. VIEW OF THE PLATING BATHS AND CONTROL PANELS. GOLD AND SILVER WERE AMONG THE MATERIALS PLATED ONTO PARTS MADE OF COPPER, STAINLESS STEEL AND STEEL. (11/15/89) - Rocky Flats Plant, Non-Nuclear Production Facility, South of Cottonwood Avenue, west of Seventh Avenue & east of Building 460, Golden, Jefferson County, CO

Nitinol Temperature Monitoring Devices

DTIC Science & Technology

1976-01-09

AD-A021 578 NITINOL TEMPERATURE MONITORING DEVICES William J. Buehler, et al Naval Surface Weapons Center Silver Spring, Maryland 9 January 1976...LABORATORY S NITINOL TEMPERATURE MONITORING DEVICES 9 JANUARY 1976 NAVAL SURFACE WEAPONS CENTER WHITE OAK LABORATORY SILVER SPRING, MARYLAND 20910 * Approved...GOVT ACCESSION NO. 3. RECIPIIENT’S CATALOG NUMBER NSWC/WOL/TR 75-140 ____ ______ 4 TITLE (and Subtitle) 5. TYPE OF REPCRT & PERIOD COVERED Nitinol

76 FR 24974 - Joint Biomedical Laboratory Research and Development and Clinical Science Research and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-03

... 7, 2011..... 8 a.m.-5 p.m..... L'Enfant Plaza Hotel. Neurobiology-C June 8, 2011..... 6 p.m.-10 p.m.... Crowne Plaza DC/Silver Spring. June 9-10, 2011.. 8 a.m.-5 p.m..... Crowne Plaza Hotel Silver Spring. Mental Health and Behav Sci-A. June 9, 2011..... 8 a.m.-5 p.m..... L'Enfant Plaza Hotel. The addresses of...

Using multiple chemical indicators to characterize and determine the age of groundwater from selected vents of the silver springs group, Central Florida, USA

USGS Publications Warehouse

Knowles, L.; Katz, B.G.; Toth, D.J.

2010-01-01

The Silver Springs Group, Florida (USA), forms the headwaters of the Silver River and supports a diverse ecosystem. The 30 headwater springs divide into five subgroups based on chemistry. Five selected spring vents were sampled in 2007 to better understand the contaminant sources and groundwater flow system. Elevated nitrate-N concentrations (>0.8mg/L) in the five spring vents likely originate from inorganic (fertilizers) and organic sources, based on nitrogen and oxygen isotope ratios of nitrate. Evidence for denitrification in the Lost River Boil spring includes enriched ??15N and ??18O, excess N2 gas, and low dissolved O2 concentrations (<0.5mg/L). Multiple age-tracer data (SF6, 3H, tritiogenic 3He) for the two uppermost springs (Mammoth East and Mammoth West) indicate a binary mixture dominated by recent recharge water (mean age 6-7 years, and 87-97% young water). Tracer data for the three downstream spring vents (Lost River Boil, Catfish Hotel-1, and Catfish Conventional Hall-1) indicate exponential mixtures with mean ages of 26-35 years. Contamination from non-atmospheric sources of CFCs and SF5CF3 precluded their use as age tracers here. Variations in chemistry were consistent with mean groundwater age, as nitrate-N and dissolved O2 concentrations were higher in younger waters, and the Ca/Mg ratio decreased with increasing mean age. ?? 2010 Springer-Verlag (outside the USA).

Using multiple chemical indicators to characterize and determine the age of groundwater from selected vents of the Silver Springs Group, central Florida, USA

NASA Astrophysics Data System (ADS)

Knowles, Leel; Katz, Brian G.; Toth, David J.

2010-12-01

The Silver Springs Group, Florida (USA), forms the headwaters of the Silver River and supports a diverse ecosystem. The 30 headwater springs divide into five subgroups based on chemistry. Five selected spring vents were sampled in 2007 to better understand the contaminant sources and groundwater flow system. Elevated nitrate-N concentrations (>0.8 mg/L) in the five spring vents likely originate from inorganic (fertilizers) and organic sources, based on nitrogen and oxygen isotope ratios of nitrate. Evidence for denitrification in the Lost River Boil spring includes enriched δ15N and δ18O, excess N2 gas, and low dissolved O2 concentrations (<0.5 mg/L). Multiple age-tracer data (SF6, 3H, tritiogenic 3He) for the two uppermost springs (Mammoth East and Mammoth West) indicate a binary mixture dominated by recent recharge water (mean age 6-7 years, and 87-97% young water). Tracer data for the three downstream spring vents (Lost River Boil, Catfish Hotel-1, and Catfish Conventional Hall-1) indicate exponential mixtures with mean ages of 26-35 years. Contamination from non-atmospheric sources of CFCs and SF5CF3 precluded their use as age tracers here. Variations in chemistry were consistent with mean groundwater age, as nitrate-N and dissolved O2 concentrations were higher in younger waters, and the Ca/Mg ratio decreased with increasing mean age.

Importance of the What, When, and Where of Mosquito Collection Events

DTIC Science & Technology

2009-01-01

Division of Entomology , Walter Reed Army Institute of Research, 503 Robert Grant Ave., Silver Spring, MD 20910 J. Med. Entomol. 46(4): 717Ð722 (2009...Department of Defense. 1 Corresponding author, e-mail: foleydes@si.edu. 0022-2585/09/0717Ð0722$04.00/0 2009 Entomological Society of America Report...PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Walter Reed Army Institute of Research,Division of Entomology ,503 Robert Grant Ave,Silver Spring,MD,20910

A Fast Response Capability within NOAA/NOS/CO-OPS

DTIC Science & Technology

2007-01-01

A Fast Response Capability within NOAA/NOS/CO-OPS P. B. Burke NOAA/National Ocean Service/CO-OPS 1305 East-West Hwy. Silver Spring, MD 20910...USA pat.burke@noaa.gov T. Graff NOAA/National Ocean Service/CO-OPS 1305 East-West Hwy. Silver Spring, MD 20910 USA tammy.graff@noaa.gov... flotation hull, an instrumentation tower mounted atop the hull and a current meter mount with a mooring attachment. The triangular tower housed two

Chemistry of ground water in the Silver Springs basin, Florida, with an emphasis on nitrate

USGS Publications Warehouse

Phelps, G.G.

2004-01-01

The Silver Springs group, in central Marion County, Florida, has a combined average discharge rate of 796 cubic feet per second and forms the headwaters of the Silver River. The springs support a diverse ecosystem and are an important cultural and economic resource. Concentrations of nitrite-plus-nitrate (nitrate-N) in water from the Main Spring increased from less than 0.5 milligrams per liter (mg/L) in the 1960s to about 1.0 mg/L in 2003. The Upper Floridan aquifer supplies the ground water to support spring discharge. This aquifer is at or near land surface in much of the ground-water basin; nutrients leached at land surface can easily percolate downward into the aquifer. Sources of nitrogen in ground water in the Silver Springs basin include atmospheric deposition, fertilizers used by agricultural and urban activities, and human and animal wastes. During 2000-2001, 56 wells in the area contributing recharge to Silver Springs were sampled for major ions, nutrients, and some trace constituents. Selected wells also were sampled for a suite of organic constituents commonly found in domestic and industrial wastewater and for the ratio of nitrogen isotopes (15N/14N) to better understand the sources of nitrate. Wells were selected to be representative of both confined and unconfined conditions of the Upper Floridan aquifer, as well as a variety of land-use types. Data from this study were compared to data collected from 25 wells in 1989-90. Concentrations of nitrate-N in ground water during this study ranged from less than the detection limit of 0.02 to 12 mg/L, with a median of 1.2 mg/L. For data from 1989-90, the range was from less than 0.02 to 3.6 mg/L, with a median of 1.04 mg/L. Water from wells in agricultural land-use areas had the highest median nitrate-N concentration (1.7 mg/L), although it is uncertain if the 12 mg/L maximum concentration was influenced by land-use activities or proximity to a septic tank. The median value for all urban land-use areas was 1.15 mg/L. Because fewer wells were in rangeland or forested areas, those categories were grouped together. The median concentration for that group was 0.09 mg/L. The ratio of 15N/14N in ground-water samples ranged from -0.5 to 11.5 per mil. The median value for ground-water samples from 35 wells, 4.9 per mil, is near the top of the range that indicates inorganic nitrogen sources. In agricultural areas, the median 15N/14N was 4.8 per mil, indicating mostly inorganic (fertilizer) sources. In urban areas, the median 15N/14N was 5.4 per mil, indicating more influence of organic nitrogen (N) sources. Thus, in both agricultural and urban areas, fertilizer is an important inorganic source of N in ground water (and, therefore, in spring water as well). The influence of organic N is more apparent in urban areas than in agricultural areas. Two distinct 15N/14N values were observed in water from the Main Spring, one indicating an inorganic nitrogen source and the other indicating a mixture of sources with a strong influence of organic nitrogen. Thirty-five wells and three springs of the Silver Springs group (the Main Spring, the Abyss, and the Blue Grotto) were sampled for a suite of 63 compounds common in wastewater. A total of 38 compounds was detected, nearly all in very low concentrations. The most frequently detected compound was the insecticide N,N-diethyl-meta-toluamide (DEET), which was detected in water from 27 wells and all three springs. The presence or absence of DEET in ground-water samples did not seem to be related to land use; however, hydrogeologic conditions at the well sites (confined or unconfined) generally did affect the presence or absence of DEET in the ground water. DEET also appears to be a useful tracer for the presence of reused water. Water samples were collected from the Main Spring and two other springs of the Silver Springs group and analyzed for concentrations of dissolved gasses and for chlorofluorocarbons (CFCs), sulfur hexaflu

75 FR 23608 - Final Flood Elevation Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-04

... Jewett +88 Town of White Springs Street. Approximately 600 feet +109 upstream of 1st Street. Timber Lake... Hamilton Avenue, Jennings, FL 32053 Town of White Springs Maps are available for inspection at the Town Hall, 10363 Bridge Street, White Springs, FL 32096 Unincorporated Areas of Hamilton County Maps are...

75 FR 65362 - Oncologic Drugs Advisory Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-22

... Hampshire Ave., Silver Spring, MD 20993-0002. Information regarding special accommodations due to a... Evaluation and Research, Food and Drug Administration, 10903 New Hampshire Ave., Bldg. 31, rm. 2417, Silver...) Soft Gelatin Capsules, [[Page 65363

Silver-induced reconstruction of an adeninate-based metal-organic framework for encapsulation of luminescent adenine-stabilized silver clusters.

PubMed

Jonckheere, Dries; Coutino-Gonzalez, Eduardo; Baekelant, Wouter; Bueken, Bart; Reinsch, Helge; Stassen, Ivo; Fenwick, Oliver; Richard, Fanny; Samorì, Paolo; Ameloot, Rob; Hofkens, Johan; Roeffaers, Maarten B J; De Vos, Dirk E

2016-05-21

Bright luminescent silver-adenine species were successfully stabilized in the pores of the MOF-69A (zinc biphenyldicarboxylate) metal-organic framework, starting from the intrinsically blue luminescent bio-MOF-1 (zinc adeninate 4,4'-biphenyldicarboxylate). Bio-MOF-1 is transformed to the MOF-69A framework by selectively leaching structural adenine linkers from the original framework using silver nitrate solutions in aqueous ethanol. Simultaneously, bright blue-green luminescent silver-adenine clusters are formed inside the pores of the recrystallized MOF-69A matrix in high local concentrations. The structural transition and concurrent changes in optical properties were characterized using a range of structural, physicochemical and spectroscopic techniques (steady-state and time-resolved luminescence, quantum yield determination, fluorescence microscopy). The presented results open new avenues for exploring the use of MOFs containing luminescent silver clusters for solid-state lighting and sensor applications.

Estimation of evapotranspiration in the Rainbow Springs and Silver Springs basins in North-Central Florida

USGS Publications Warehouse

Knowles, Leel

1996-01-01

Estimates of evapotranspiration (ET) for the Rainbow and Silver Springs ground-water basins in north-central Florida were determined using a regional water-~budget approach and compared to estimates computed using a modified Priestley-Taylor (PT) model calibrated with eddy-correlation data. Eddy-correlation measurements of latent 0~E) and sensible (H) heat flux were made monthly for a few days at a time, and the PT model was used to estimate 3,E between times of measurement during the 1994 water year. A water-budget analysis for the two-basin area indicated that over a 30-year period (196594) annual rainfall was 51.7 inches. Of the annual rainfall, ET accounted for about 37.9 inches; springflow accounted for 13.1 inches; and the remaining 0.7 inch was accounted for by stream-flow, by ground-water withdrawals from the Floridan aquifer system, and by net change in storage. For the same 30-year period, the annual estimate of ET for the Silver Springs basin was 37.6 inches and was 38.5 inches for the Rainbow Springs basin. Wet- and dry-season estimates of ET for each basin averaged between nearly 19 inches and 20 inches, indicating that like rainfall, ET rates during the 4-month wet season were about twice the ET rates during the 8-month dry season. Wet-season estimates of ET for the Rainbow Springs and Silver Springs basins decreased 2.7 inches, and 3.4 inches, respectively, over the 30-year period; whereas, dry-season estimates for the basins decreased about 0.4 inch and1.0 inch, respectively, over the 30-year period. This decrease probably is related to the general decrease in annual rainfall and reduction in net radiation over the basins during the 30-year period. ET rates computed using the modified PT model were compared to rates computed from the water budget for the 1994 water year. Annual ET, computed using the PT model, was 32.0 inches, nearly equal to the ET water-budget estimate of 31.7 inches computed for the Rainbow Springs and Silver Springs basins. Modeled ET rates for 1994 ranged from 14.4 inches per year in January to 51.6 inches per year in May. Water-budget ET rates for 1994 ranged from 12.0 inches per year in March to 61.2 inches per year in July. Potential evapotranspiration rates for 1994 averaged 46.8 inches per year and ranged from 21.6 inches per year in January to 74.4 inches per year in May. Lake evaporation rates averaged 47.1 inches per year and ranged from 18.0 inches per year in January to 72.0 inches per year in May 1994.

Brain-Eating Amoebae: Silver Nanoparticle Conjugation Enhanced Efficacy of Anti-Amoebic Drugs against Naegleria fowleri.

PubMed

Rajendran, Kavitha; Anwar, Ayaz; Khan, Naveed Ahmed; Siddiqui, Ruqaiyyah

2017-12-20

The overall aim of this study was to determine whether conjugation with silver nanoparticles enhances effects of available drugs against primary amoebic meningoencephalitis due to Naegleria fowleri. Amphotericin B, Nystatin, and Fluconazole were conjugated with silver nanoparticles, and synthesis was confirmed using UV-visible spectrophotometry. Atomic force microscopy determined their size in range of 20-100 nm. To determine amoebicidal effects, N. fowleri were incubated with drugs-conjugated silver nanoparticles, silver nanoparticles alone, and drugs alone. The findings revealed that silver nanoparticles conjugation significantly enhanced antiamoebic effects of Nystatin and Amphotericin B but not Fluconazole at micromolar concentrations, compared with the drugs alone. For the first time, our findings showed that silver nanoparticle conjugation enhances efficacy of antiamoebic drugs against N. fowleri. Given the rarity of the disease and challenges in developing new drugs, it is hoped that modifying existing drugs to enhance their antiamoebic effects is a useful avenue that holds promise in improving the treatment of brain-eating amoebae infection due to N. fowleri.

Flow Synthesis of Silver Nanowires for Semitransparent Solar Cell Electrodes: A Life Cycle Perspective.

PubMed

Espinosa, Nieves; Søndergaard, Roar R; Jørgensen, Mikkel; Krebs, Frederik C

2016-04-21

Silver nanowires (AgNWs) were prepared on a 5 g scale using either the well-known batch synthesis following the polyol method or a new flow synthesis method. The AgNWs were employed as semitransparent electrode materials in organic photovoltaics and compared to traditional printed silver electrodes based on micron sized silver flakes using life cycle analysis and environmental impact analysis methods. The life cycle analysis of AgNWs confirms that they provide an avenue to low-impact semitransparent electrodes. We find that the benefit of AgNWs in terms of embodied energy is less pronounced than generally assumed but that the toxicological and environmental benefits are significant. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Parsimonious Hydrologic and Nitrate Response Models For Silver Springs, Florida

NASA Astrophysics Data System (ADS)

Klammler, Harald; Yaquian-Luna, Jose Antonio; Jawitz, James W.; Annable, Michael D.; Hatfield, Kirk

2014-05-01

Silver Springs with an approximate discharge of 25 m3/sec is one of Florida's first magnitude springs and among the largest springs worldwide. Its 2500-km2 springshed overlies the mostly unconfined Upper Floridan Aquifer. The aquifer is approximately 100 m thick and predominantly consists of porous, fractured and cavernous limestone, which leads to excellent surface drainage properties (no major stream network other than Silver Springs run) and complex groundwater flow patterns through both rock matrix and fast conduits. Over the past few decades, discharge from Silver Springs has been observed to slowly but continuously decline, while nitrate concentrations in the spring water have enormously increased from a background level of 0.05 mg/l to over 1 mg/l. In combination with concurrent increases in algae growth and turbidity, for example, and despite an otherwise relatively stable water quality, this has given rise to concerns about the ecological equilibrium in and near the spring run as well as possible impacts on tourism. The purpose of the present work is to elaborate parsimonious lumped parameter models that may be used by resource managers for evaluating the springshed's hydrologic and nitrate transport responses. Instead of attempting to explicitly consider the complex hydrogeologic features of the aquifer in a typically numerical and / or stochastic approach, we use a transfer function approach wherein input signals (i.e., time series of groundwater recharge and nitrate loading) are transformed into output signals (i.e., time series of spring discharge and spring nitrate concentrations) by some linear and time-invariant law. The dynamic response types and parameters are inferred from comparing input and output time series in frequency domain (e.g., after Fourier transformation). Results are converted into impulse (or step) response functions, which describe at what time and to what magnitude a unitary change in input manifests at the output. For the hydrologic response model, frequency spectra of groundwater recharge and spring discharge suggest an exponential response model, which may explain a significant portion of spring discharge variability with only two fitting parameters (mean response time 2.4 years). For the transport model, direct use of nitrate data is confounded by inconsistent data and a strong trend. Instead, chloride concentrations in rainfall and at the spring are investigated as a surrogate candidate. Preliminary results indicate that the transport response function of the springshed as a whole may be of the gamma type, which possesses both a larger initial peak as well as a longer tail than the exponential response function. This is consistent with the large range of travel times to be expected between input directly into fast conduits connected to the spring (e.g., though sinkholes) and input or back-diffusion from the rock matrix. The result implies that reductions in nitrate input, especially at remote and hydraulically not well connected locations, will only manifest in a rather delayed and smoothed out form in concentration observed at the spring.

Antibacterial properties and mechanisms of gold-silver nanocages

NASA Astrophysics Data System (ADS)

Wang, Yulan; Wan, Jiangshan; Miron, Richard J.; Zhao, Yanbin; Zhang, Yufeng

2016-05-01

Despite the number of antibiotics used in routine clinical practice, bacterial infections continue to be one of the most important challenges faced in humans. The main concerns arise from the continuing emergence of antibiotic-resistant bacteria and the difficulties faced with the pharmaceutical development of new antibiotics. Thus, advancements in the avenue of novel antibacterial agents are essential. In this study, gold (Au) was combined with silver (Ag), a well-known antibacterial material, to form silver nanoparticles producing a gold-silver alloy structure with hollow interiors and porous walls (gold-silver nanocage). This novel material was promising in antibacterial applications due to its better biocompatibility than Ag nanoparticles, potential in photothermal effects and drug delivery ability. The gold-silver nanocage was then tested for its antibacterial properties and the mechanism involved leading to its antibacterial properties. This study confirms that this novel gold-silver nanocage has broad-spectrum antibacterial properties exerting its effects through the destruction of the cell membrane, production of reactive oxygen species (ROS) and induction of cell apoptosis. Therefore, we introduce a novel gold-silver nanocage that serves as a potential nanocarrier for the future delivery of antibiotics.

8. Photograph of a photograph in possession of Rock Island ...

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

8. Photograph of a photograph in possession of Rock Island Arsenal Historical Office. FIRST FLOOR, WEST WING; SHOWING PRATT & WHITNEY RIFLING MACHINES FOR MANUFACTURING 1903 MODEL SPRING-FIELD RIFLE. DATED JULY 4, 1904. - Rock Island Arsenal, Building No. 60, Rodman Avenue between Gillespie Avenue & First Street, Rock Island, Rock Island County, IL

Disaster Planning Guidelines for Fire Chiefs.

DTIC Science & Technology

1980-07-01

book Money Receipts e I pad white squared paper * I roll masking tape (8 X 13) (-" × 60yds) * 3 spring clips * 3 felt tip markers (red, e I pkg. freezer...Avenue COMMIT EE HaRm Washington. D.C. 20012 C.Holy Redeemer Rectory (202) 723-0800 C. Neil Molenaar 9705 Summit Avenue Director, Domestic Programs

76 FR 9320 - Foreign-Trade Zone 274-Butte-Silver Bow, MT; Application for Manufacturing Authority REC Silicon...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-17

... Silicon to realize logistical benefits through the use of weekly customs entry procedures. Customs duties... Avenue, NW., Washington, DC 20230-0002, and in the ``Reading Room'' section of the Board's Web site...

Walnut Springs Interest Unit, Fairmount Avenue School. Primary Unit--Team I.

ERIC Educational Resources Information Center

State College Area School District, PA.

This environmental education teaching guide was designed for primary teachers who may want to develop their own environmental education units or who may wish to integrate the units contained in the guide into their own curriculum. The units in the guide were developed by primary teachers and reflect the experiences of the Fairmont Avenue School…

UV-light assisted patterned metallization of textile fabrics

NASA Astrophysics Data System (ADS)

Bahners, Thomas; Gebert, Beate; Prager, Andrea; Hartmann, Nils; Hagemann, Ulrich; Gutmann, Jochen S.

2018-04-01

A UV-assisted process allows full-faced or local deposition of silver domains on textiles made of natural as well as synthetic fibers, which act as nuclei for subsequent galvanic metallization. SEM and XPS analyses indicate that the process generates particulate depositions - particles, aggregates - of elementary silver. Masking the UV irradiation confines silver deposition strictly to the exposed areas thus allowing patterning. Adhesion of the deposited silver is high on the studied natural fiber cotton and polyamide fibers. Adhesion on smooth and chemically inert synthethic fibers such as, e.g., poly(ethylene terephthalate) or para- and meta-aramids could be enhanced by finishing with poly(vinylamine) thus providing complex-forming amino groups. Although the process does not deposit a closed, electrically conducting layer, all studied samples could be metallized by galvanization. The resulting metal coatings exhibit high conductivity and wash stability. Following a patterned silver deposition, the subsequent galvanic metallization produced conductive patterns of identical geometry thus opening an avenue towards printed circuits on textile fabrics.

Silver-induced reconstruction of an adeninate-based metal–organic framework for encapsulation of luminescent adenine-stabilized silver clusters† †Electronic supplementary information (ESI) available: Experimental details and additional structural, physicochemical and optical characterisation. See DOI: 10.1039/c6tc00260a Click here for additional data file.

PubMed Central

Jonckheere, Dries; Coutino-Gonzalez, Eduardo; Baekelant, Wouter; Bueken, Bart; Reinsch, Helge; Stassen, Ivo; Fenwick, Oliver; Richard, Fanny; Samorì, Paolo; Ameloot, Rob; Hofkens, Johan

2016-01-01

Bright luminescent silver-adenine species were successfully stabilized in the pores of the MOF-69A (zinc biphenyldicarboxylate) metal–organic framework, starting from the intrinsically blue luminescent bio-MOF-1 (zinc adeninate 4,4′-biphenyldicarboxylate). Bio-MOF-1 is transformed to the MOF-69A framework by selectively leaching structural adenine linkers from the original framework using silver nitrate solutions in aqueous ethanol. Simultaneously, bright blue-green luminescent silver-adenine clusters are formed inside the pores of the recrystallized MOF-69A matrix in high local concentrations. The structural transition and concurrent changes in optical properties were characterized using a range of structural, physicochemical and spectroscopic techniques (steady-state and time-resolved luminescence, quantum yield determination, fluorescence microscopy). The presented results open new avenues for exploring the use of MOFs containing luminescent silver clusters for solid-state lighting and sensor applications. PMID:28496980

78 FR 44251 - Regulatory Agenda

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-23

... Administration, Center for Drug Evaluation and Research, WO 22, Room 5487, 10903 New Hampshire Avenue, Silver..., Food and Drug Administration, Center for Drug Evaluation and Research, WO 22, Room 5416, 10903 New... Drug Administration, Center for Drug Evaluation and Research, WO 22, Room 5487, 10903 New Hampshire...

E-MRS Spring Meeting - Nanophotonic Materials Session

DTIC Science & Technology

2004-05-27

are also analyzed, including combinations of recently realized nanorings [5]. The effective optical properties of various families of metamaterials...present calculations of the distant-dependent dissipated power as a function of wave vector for an oscillating dipole above the silver /dielectric...the measurement of leakage radiation to the excitation and propagation of SPPs in silver films with various surface nanostructures, thereby gaining

23. The Stroud Building beard the 'Temme Springs' advertisement. Westfacing ...

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

23. The Stroud Building beard the 'Temme Springs' advertisement. West-facing windows of the entire block are protected from the afternoon sun by awnings. The north-facing windows of the second-story restaurant were later blocked by an adjacent two-story building. Circa 1914. Credit PPL. - Stroud Building, 31-33 North Central Avenue, Phoenix, Maricopa County, AZ

Soviet Research and Development of High-Power Gap Switches

DTIC Science & Technology

1974-01-01

mounted between 5 and trigger electrode 7. The BaTi03 disc face on the side of electrode 7 is coated with silver , the coating extending over the...pressed by springs, coaxial with the cylinder body of the gap, against contacts 4, which are soldered to the silver coating of the cylinder representing...space. Fig. 3 — Gap switch 1 — BaTi03 disc 2 and 3 — electrodes 4 — silver coating 5 — air space The pulse repetition frequency is 3 x lO4 Hz up to

Contributions to the gold metallogeny of northern Nevada

USGS Publications Warehouse

Tosdal, Richard M.

1998-01-01

Nevada is one of the Earth's premier gold producing regions, accounting for approximately 64 percent of the U.S and nine percent of the world total. The impact of these mines on nearby local economies and on our national balance of payments is profound, and will continue well into the next century. Of principal importance in this region are giant sedimentary-rock-hosted (Carlin-type) deposits. These are some of the world's largest deposits, but yet are poorly understood. Other sedimentary-rock hosted deposits in the region, the distal-disseminated Ag-Au type, are genetically related to shallow plutonic complexes. Hot-spring gold-silver systems associated with Tertiary volcanic rocks represent a third type of precious metal deposit in northern Nevada. These deposits, despite being generally smaller than sedimentary-rock-hosted gold deposits, are also important gold-silver resources. Aspects about the geologic and metallogenic setting of gold-silver deposits in northern Nevada are addressed in the twenty-two chapters that compose this volume. The volume is organized along four themes: (1) crustal structure; (2) Carlin-type deposits; (3) pluton-related gold-silver deposits near Battle Mountain; and (4) hot-spring gold-silver deposits. This Open-File Report, the result of ongoing geologic and mineral-resource investigations, provides a basis for mineral exploration, for land-use planning decisions, and for environmental questions in northern Nevada.

Removal of Protein Capping Enhances the Antibacterial Efficiency of Biosynthesized Silver Nanoparticles

PubMed Central

Jain, Navin; Bhargava, Arpit; Rathi, Mohit; Dilip, R. Venkataramana; Panwar, Jitendra

2015-01-01

The present study demonstrates an economical and environmental affable approach for the synthesis of “protein-capped” silver nanoparticles in aqueous solvent system. A variety of standard techniques viz. UV-visible spectroscopy, transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) measurements were employed to characterize the shape, size and composition of nanoparticles. The synthesized nanoparticles were found to be homogenous, spherical, mono-dispersed and covered with multi-layered protein shell. In order to prepare bare silver nanoparticles, the protein shell was removed from biogenic nanoparticles as confirmed by UV-visible spectroscopy, FTIR and photoluminescence analysis. Subsequently, the antibacterial efficacy of protein-capped and bare silver nanoparticles was compared by bacterial growth rate and minimum inhibitory concentration assay. The results revealed that bare nanoparticles were more effective as compared to the protein-capped silver nanoparticles with varying antibacterial potential against the tested Gram positive and negative bacterial species. Mechanistic studies based on ROS generation and membrane damage suggested that protein-capped and bare silver nanoparticles demonstrate distinct mode of action. These findings were strengthened by the TEM imaging along with silver ion release measurements using inductively coupled plasma atomic emission spectroscopy (ICP-AES). In conclusion, our results illustrate that presence of protein shell on silver nanoparticles can decrease their bactericidal effects. These findings open new avenues for surface modifications of nanoparticles to modulate and enhance their functional properties. PMID:26226385

A long-term study examining the antibacterial effectiveness of Agion silver zeolite technology on door handles within a college campus.

PubMed

Potter, B A; Lob, M; Mercaldo, R; Hetzler, A; Kaistha, V; Khan, H; Kingston, N; Knoll, M; Maloy-Franklin, B; Melvin, K; Ruiz-Pelet, P; Ozsoy, N; Schmitt, E; Wheeler, L; Potter, M; Rutter, M A; Yahn, G; Parente, D H

2015-02-01

Laboratory studies have shown that small concentrations of silver are effective at inhibiting the growth micro-organisms through the disruption of important cell structures and processes. The additional ability to incorporate silver into surfaces has increased the usage of silver in the medical field and expanded its use into the consumer market. To understand the impact of increased silver-containing antimicrobial use, it is important to determine whether silver-based consumer goods are effective at reducing bacterial populations. Our study examined the antibacterial effectiveness of Agion silver zeolite technology applied to 25 silver- and control-coated door handles across a college campus. Door handles were sampled for 6 week periods in both the fall and spring semester, and bacteria were cultured and enumerated on tryptic soy agar (TSA), MacConkey agar (MAC) and mannitol salt agar (MSA). A significant difference was observed between the bacterial populations isolated from silver- and control-coated door handles after 3 years. However, bacteria were consistently isolated from silver-coated door handles suggesting that the silver zeolite was only effective against a portion of the bacterial populations, and further studies are necessary to determine the identities of the isolated bacteria and the prevalence of silver resistance. © 2014 The Society for Applied Microbiology.

State of STEM (SoSTEM) Address

NASA Image and Video Library

2014-01-29

Montgomery Blair High School Student Newspaper “Silver Chips” Online Editor-in-Chief Aanchal Johri, right, and Photo Editor Emma Howells, left, from Silver Spring, MD. interview NASA Astronaut Joe Acaba at the annual White House State of Science, Technology, Engineering, and Math (SoSTEM) address, Wednesday, Jan. 29, 2014, in the South Court Auditorium in the Eisenhower Executive Office Building on the White House complex in Washington. Photo Credit: (NASA/Bill Ingalls)

Relationships between stem diameter, sapwood area, leaf area and transpiration in a young mountain ash forest.

PubMed

Vertessy, R A; Benyon, R G; O'Sullivan, S K; Gribben, P R

1995-09-01

We examined relationships between stem diameter, sapwood area, leaf area and transpiration in a 15-year-old mountain ash (Eucalyptus regnans F. Muell.) forest containing silver wattle (Acacia dealbata Link.) as a suppressed overstory species and mountain hickory (Acacia frigescens J.H. Willis) as an understory species. Stem diameter explained 93% of the variation in leaf area, 96% of the variation in sapwood area and 88% of the variation in mean daily spring transpiration in 19 mountain ash trees. In seven silver wattle trees, stem diameter explained 87% of the variation in sapwood area but was a poor predictor of the other variables. When transpiration measurements from individual trees were scaled up to a plot basis, using stem diameter values for 164 mountain ash trees and 124 silver wattle trees, mean daily spring transpiration rates of the two species were 2.3 and 0.6 mm day(-1), respectively. The leaf area index of the plot was estimated directly by destructive sampling, and indirectly with an LAI-2000 plant canopy analyzer and by hemispherical canopy photography. All three methods gave similar results.

15 CFR 930.127 - Briefs and supporting materials.

Code of Federal Regulations, 2010 CFR

2010-01-01

... General Counsel for Ocean Services (GCOS), NOAA, 1305 East West Highway, Room 6111 SSMC4, Silver Spring... (Continued) NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE OCEAN AND COASTAL...

15 CFR 930.127 - Briefs and supporting materials.

Code of Federal Regulations, 2011 CFR

2011-01-01

... General Counsel for Ocean Services (GCOS), NOAA, 1305 East West Highway, Room 6111 SSMC4, Silver Spring... (Continued) NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE OCEAN AND COASTAL...

Production of polysaccharide-based bioflocculant for the synthesis of silver nanoparticles by Streptomyces sp.

PubMed

Manivasagan, Panchanathan; Kang, Kyong-Hwa; Kim, Dong Gyu; Kim, Se-Kwon

2015-01-01

Polysaccharide-based bioflocculants have attracted considerable attention in recent years due to their biodegradable, harmless and negligible secondary pollution. Bioflocculants are organic macromolecular substances secreted by microorganisms. A simple, cost-effective and green method was developed for the biosynthesis of silver nanoparticles using polysaccharides as reducing and stabilizing agents. In this paper, we report on the production and optimization of polysaccharide-based bioflocculant for the green synthesis of silver nanoparticles by Streptomyces sp. MBRC-91. Medium composition and culture conditions for polysaccharide-based bioflocculants were statistically optimized by response surface methodology (RSM). The bioflocculant production was statistically optimized with most significant factors, namely palm jaggery (18.73g/L), yeast extract (2.07g/L), K2HPO4 (3.74g/L) and NaCl (0.38g/L), respectively. The biosynthesized silver nanoparticles were characterized by UV-vis spectroscopy, XRD, FTIR, FESEM, EDXA and HRTEM. The biosynthesized silver nanoparticles revealed strong antibacterial activity in sewage water and this result could make a new avenue in the wastewater treatment. Therefore, the biosynthesized silver nanoparticles can be extended as an alternative for the development of new bactericidal bionanomaterials for wastewater treatment and biotechnological applications. Copyright © 2015 Elsevier B.V. All rights reserved.

8. VIEW SOUTHWEST, INTERIOR VIEW, WIND TUNNEL 139 Naval ...

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

8. VIEW SOUTHWEST, INTERIOR VIEW, WIND TUNNEL 139 - Naval Surface Warfare Center, Subsonic Wind Tunnel Building, Bounded by Clara Barton Parkway & McArthur Boulevard, Silver Spring, Montgomery County, MD

77 FR 33199 - Marine Mammals; File No. 14534

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-05

... Technology, Silver Spring, MD, (Brandon Southall, Ph.D.--Principal Investigator) for research on marine...) will not operate to the disadvantage of such endangered species; and (3) is consistent with the...

Cold Saline Springs in Permafrost on Earth and Mars

NASA Technical Reports Server (NTRS)

Heldann, Jennifer; Toon, Owen B.

2003-01-01

This report summarizes the research results which have emanated from work conducted on Cold Saline Springs in Permafrost on Earth and Mars. Three separate avenues of research including 1) terrestrial field work, 2) analysis of spacecraft data, and 3) numerical modeling were explored to provide a comprehensive investigation of water in the polar desert environments of both Earth and Mars. These investigations and their results are summarized.

12. VIEW EAST, BUILDING 12 INTERIOR, WIND TUNNEL 157 ...

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

12. VIEW EAST, BUILDING 12 INTERIOR, WIND TUNNEL 157 - Naval Surface Warfare Center, Transonic Wind Tunnel Building, Bounded by Clara Barton Parkway & McArthur Boulevard, Silver Spring, Montgomery County, MD

2. VIEW SOUTH OF WIND TUNNEL 157, NORTH ELEVATION ...

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

2. VIEW SOUTH OF WIND TUNNEL 157, NORTH ELEVATION - Naval Surface Warfare Center, Transonic Wind Tunnel Building, Bounded by Clara Barton Parkway & McArthur Boulevard, Silver Spring, Montgomery County, MD

21 CFR 314.445 - Guidance documents.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Evaluation and Research, Food and Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD 20993-0002... HUMAN USE APPLICATIONS FOR FDA APPROVAL TO MARKET A NEW DRUG Miscellaneous Provisions § 314.445 Guidance...

21 CFR 314.445 - Guidance documents.

Code of Federal Regulations, 2012 CFR

2012-04-01

... Evaluation and Research, Food and Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD 20993-0002... HUMAN USE APPLICATIONS FOR FDA APPROVAL TO MARKET A NEW DRUG Miscellaneous Provisions § 314.445 Guidance...

21 CFR 314.445 - Guidance documents.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Evaluation and Research, Food and Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD 20993-0002... HUMAN USE APPLICATIONS FOR FDA APPROVAL TO MARKET A NEW DRUG Miscellaneous Provisions § 314.445 Guidance...

21 CFR 314.445 - Guidance documents.

Code of Federal Regulations, 2013 CFR

2013-04-01

... Evaluation and Research, Food and Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD 20993-0002... HUMAN USE APPLICATIONS FOR FDA APPROVAL TO MARKET A NEW DRUG Miscellaneous Provisions § 314.445 Guidance...

50 CFR 600.501 - Vessel permits.

Code of Federal Regulations, 2013 CFR

2013-10-01

... East West Highway, Silver Spring, Maryland 20910. All applicants should allow 90 days for review and... specified time frame voids the permit, and all penalties involved will accrue to the previous owner. (l...

50 CFR 600.501 - Vessel permits.

Code of Federal Regulations, 2011 CFR

2011-10-01

... East West Highway, Silver Spring, Maryland 20910. All applicants should allow 90 days for review and... specified time frame voids the permit, and all penalties involved will accrue to the previous owner. (l...

50 CFR 600.501 - Vessel permits.

Code of Federal Regulations, 2012 CFR

2012-10-01

... East West Highway, Silver Spring, Maryland 20910. All applicants should allow 90 days for review and... specified time frame voids the permit, and all penalties involved will accrue to the previous owner. (l...

50 CFR 600.501 - Vessel permits.

Code of Federal Regulations, 2010 CFR

2010-10-01

... East West Highway, Silver Spring, Maryland 20910. All applicants should allow 90 days for review and... specified time frame voids the permit, and all penalties involved will accrue to the previous owner. (l...

50 CFR 600.501 - Vessel permits.

Code of Federal Regulations, 2014 CFR

2014-10-01

... East West Highway, Silver Spring, Maryland 20910. All applicants should allow 90 days for review and... specified time frame voids the permit, and all penalties involved will accrue to the previous owner. (l...

75 FR 68605 - Marine Mammals

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-08

..., Silver Spring, MD 20910; phone (301) 713-2289; fax (301) 713-0376; and Northwest Region, NMFS, 7600 Sand... issuance of the permit would not significantly impact the quality of the human environment and that...

7. VIEW NORTHWEST OF SUBSONIC WIND TUNNEL BUILDING TO TRANSONIC ...

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

7. VIEW NORTHWEST OF SUBSONIC WIND TUNNEL BUILDING TO TRANSONIC WIND TUNNEL BUILDING - Naval Surface Warfare Center, Bounded by Clara Barton Parkway & McArthur Boulevard, Silver Spring, Montgomery County, MD

2. VIEW SOUTH OF TRANSONIC WIND TUNNEL BUILDING AND SUPERSONIC ...

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

2. VIEW SOUTH OF TRANSONIC WIND TUNNEL BUILDING AND SUPERSONIC WIND TUNNEL BUILDING - Naval Surface Warfare Center, Bounded by Clara Barton Parkway & McArthur Boulevard, Silver Spring, Montgomery County, MD

5. VIEW NORTHWEST OF SUBSONIC WIND TUNNEL BUILDING TO TRANSONIC ...

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

5. VIEW NORTHWEST OF SUBSONIC WIND TUNNEL BUILDING TO TRANSONIC WIND TUNNEL BUILDING - Naval Surface Warfare Center, Bounded by Clara Barton Parkway & McArthur Boulevard, Silver Spring, Montgomery County, MD

1. VIEW SOUTHWEST OF SUBSONIC WIND TUNNEL BUILDING AND TRANSONIC ...

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

1. VIEW SOUTHWEST OF SUBSONIC WIND TUNNEL BUILDING AND TRANSONIC WIND TUNNEL BUILDING - Naval Surface Warfare Center, Bounded by Clara Barton Parkway & McArthur Boulevard, Silver Spring, Montgomery County, MD

3. VIEW SOUTHEAST OF TRANSONIC WIND TUNNEL BUILDING TO SUBSONIC ...

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

3. VIEW SOUTHEAST OF TRANSONIC WIND TUNNEL BUILDING TO SUBSONIC WIND TUNNEL BUILDING - Naval Surface Warfare Center, Bounded by Clara Barton Parkway & McArthur Boulevard, Silver Spring, Montgomery County, MD

4. VIEW NORTHWEST OF SUPERSONIC WIND TUNNEL BUILDING TO TRANSONIC ...

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

4. VIEW NORTHWEST OF SUPERSONIC WIND TUNNEL BUILDING TO TRANSONIC WIND TUNNEL BUILDING - Naval Surface Warfare Center, Bounded by Clara Barton Parkway & McArthur Boulevard, Silver Spring, Montgomery County, MD

13. VIEW NORTHEAST, BUILDING 12 INTERIOR, WIND TUNNEL FAN ASSEMBLY ...

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

13. VIEW NORTHEAST, BUILDING 12 INTERIOR, WIND TUNNEL FAN ASSEMBLY - Naval Surface Warfare Center, Transonic Wind Tunnel Building, Bounded by Clara Barton Parkway & McArthur Boulevard, Silver Spring, Montgomery County, MD

Detail view of east northeast elevation to show steps and ...

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

Detail view of east northeast elevation to show steps and lanterns; note causeway to Swiss Chalet in background - National Park Seminary, Japanese Pagoda, 2805 Linden Lane, Silver Spring, Montgomery County, MD

75 FR 39665 - Marine Mammals; File No. 14534

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-12

... Office of Science and Technology, Silver Spring, MD (Responsible Party: Ned Cyr, Director) has been... permit: (1) was applied for in good faith; (2) will not operate to the disadvantage of such endangered...

Disclaimer - NOAA's National Weather Service

Science.gov Websites

from this server through the Internet is not guaranteed. Official NWS dissemination systems which can Weather Service 1325 East West Highway Silver Spring, MD 20910 Page Author: NWS Internet Services Team

Perspective view looking from the northwest from approximately the same ...

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

Perspective view looking from the northwest from approximately the same vantage point as in MD-1109-19 - National Park Seminary, Colonial House, 2745 Dewitt Circle, Silver Spring, Montgomery County, MD

Perspective view looking from the northeast, from approximately the same ...

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

Perspective view looking from the northeast, from approximately the same vantage point as in MD-1109-K-12 - National Park Seminary, Japanese Bungalow, 2801 Linden Lane, Silver Spring, Montgomery County, MD

Interior view, perspective view looking from the east southeast to ...

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

Interior view, perspective view looking from the east southeast to fireplace and mantel - National Park Seminary, Music Hall, Linden Lane at western edge of campus, Silver Spring, Montgomery County, MD

Interior view, room 1103 northeast anteroom, general view to show ...

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

Interior view, room 1103 northeast anteroom, general view to show fireplace and windows - National Park Seminary, Music Hall, Linden Lane at western edge of campus, Silver Spring, Montgomery County, MD

Mineral Resources of the Black Mountains North and Burns Spring Wilderness Study Areas, Mohave County, Arizona

USGS Publications Warehouse

Conrad, James E.; Hill, Randall H.; Jachens, Robert C.; Neubert, John T.

1990-01-01

At the request of the U.S. Bureau of Land Management, approximately 19,300 acres of the Black Mountains North Wilderness Study Area (AZ-020-009) and 23,310 acres of the Burns Spring Wilderness Study Area (AZ-02D-010) were evaluated for mineral resources and mineral resource potential. In this report, the area studied is referred to, collectively or individually, as the 'wilderness study area' or simply 'the study area'; any reference to the Black Mountains North or Burns Spring Wilderness Study Areas refers only to that part of the wilderness study area for which a mineral survey was requested by the U.S. Bureau of Land Management. The study area is located in western Arizona, about 30 mi northwest of Kingman. There are no identified resources in the study area. An area surrounding the Portland mine and including the southern part of the Black Mountains North Wilderness Study Area and the extreme northwestern part of the Burns Spring Wilderness Study Area has high resource potential for gold and moderate resource potential for silver, lead, and mercury. The area surrounding this and including much of the northern part of the Burns Spring Wilderness Study Area has moderate potential for gold, silver, and lead. The northeastern corner of the Black Mountains North Wilderness Study Area has moderate potential for gold and low potential for silver, copper, and molybdenum resources. The central part, including the narrow strip of land just west of the central part, of the Black Mountains North Wilderness Study Area and the southern and extreme eastern parts of the Burns Spring Wilderness Study Area have low resource potential for gold. The central and southern parts of the Black Mountains North Wilderness Study Area and all but the southwestern part of the Burns Spring Wilderness Study Area have moderate resource potential for perlite. Moderate resource potential for zeolites is assigned to a large area around the Portland mine that includes parts of both study areas, to a narrow strip of land just west of the central part of the Black Mountains North Wilderness Study Area, and to all but the southwest corner of the Burns Spring Wilderness Study Area. There is no potential for oil and gas in either study area. Sand and gravel are present in both study areas, but abundant quantities of these resources are available closer to existing markets.

6. VIEW NORTH, INTERIOR VIEW OF BUILDING 11, SUPERSONIC WIND ...

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

6. VIEW NORTH, INTERIOR VIEW OF BUILDING 11, SUPERSONIC WIND TUNNEL - Naval Surface Warfare Center, Supersonic Wind Tunnel Building, Bounded by Clara Barton Parkway & McArthur Boulevard, Silver Spring, Montgomery County, MD

View from beneath causeway extension looking back to causeway and ...

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

View from beneath causeway extension looking back to causeway and pavilions (northwest generally); note Dog Bridge in background - National Park Seminary, Chateau Causeways, Between Linden Lane & Beach Drive, Silver Spring, Montgomery County, MD

21 CFR 900.21 - Application for approval as a certification agency.

Code of Federal Regulations, 2011 CFR

2011-04-01

..., Silver Spring, MD 20993-0002, in writing, of its desire to be approved as a certification agency. (2... deficiencies discovered during inspections or by other means; (M) Policies and procedures for additional...

15 CFR 930.125 - Notice of appeal and application fee to the Secretary.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Counsel for Ocean Services (GCOS), 1305 East West Highway, Room 6111 SSMC 4, Silver Spring, Maryland 20910... OCEAN AND COASTAL RESOURCE MANAGEMENT FEDERAL CONSISTENCY WITH APPROVED COASTAL MANAGEMENT PROGRAMS...

15 CFR 930.125 - Notice of appeal and application fee to the Secretary.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Counsel for Ocean Services (GCOS), 1305 East West Highway, Room 6111 SSMC 4, Silver Spring, Maryland 20910... OCEAN AND COASTAL RESOURCE MANAGEMENT FEDERAL CONSISTENCY WITH APPROVED COASTAL MANAGEMENT PROGRAMS...

75 FR 8303 - Marine Mammals; File No. 13430

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-24

..., Silver Spring, MD 20910; phone (301) 713-2289; fax (301) 713-0376; and Northwest Region, NMFS, 7600 Sand... impact the quality of the human environment and that preparation of an environmental impact statement was...

77 FR 40859 - Marine Mammals; File No. 14097

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-11

... impact the quality of the human environment and that preparation of an environmental impact statement was..., Silver Spring, MD 20910; phone (301)427-8401; fax (301)713-0376; Northwest Region, NMFS, 7600 Sand Point...

Interior view, room 1103, view of fireplace and mantel, and ...

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

Interior view, room 1103, view of fireplace and mantel, and inglenook, looking from the southeast - National Park Seminary, Music Hall, Linden Lane at western edge of campus, Silver Spring, Montgomery County, MD

1. GENERAL VIEW SHOWING FRONT EAST FACADE, FROM SOUTHEAST. Photo ...

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

1. GENERAL VIEW SHOWING FRONT EAST FACADE, FROM SOUTHEAST. Photo supplied by the Florida Division of Archives, History and Records Management, Tallahasse, Florida. - Sulphur Springs Hotel, 8122 North Nebraska Avenue, Tampa, Hillsborough County, FL

2. VIEW SOUTH OF WIND TUNNEL 138 AND COOLING SYSTEM ...

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

2. VIEW SOUTH OF WIND TUNNEL 138 AND COOLING SYSTEM 140, NORTH ELEVATION - Naval Surface Warfare Center, Subsonic Wind Tunnel Building, Bounded by Clara Barton Parkway & McArthur Boulevard, Silver Spring, Montgomery County, MD

32 CFR 536.30 - Action upon receipt of claim.

Code of Federal Regulations, 2014 CFR

2014-07-01

... in any other format, shall be scanned into a computer and uploaded onto the TSCA database so that it... Medicine, Armed Forces Institute of Pathology, 1335 E. West Highway, #6-100, Silver Spring, MD 20910-6254...

32 CFR 536.30 - Action upon receipt of claim.

Code of Federal Regulations, 2012 CFR

2012-07-01

... in any other format, shall be scanned into a computer and uploaded onto the TSCA database so that it... Medicine, Armed Forces Institute of Pathology, 1335 E. West Highway, #6-100, Silver Spring, MD 20910-6254...

32 CFR 536.30 - Action upon receipt of claim.

Code of Federal Regulations, 2011 CFR

2011-07-01

... in any other format, shall be scanned into a computer and uploaded onto the TSCA database so that it... Medicine, Armed Forces Institute of Pathology, 1335 E. West Highway, #6-100, Silver Spring, MD 20910-6254...

32 CFR 536.30 - Action upon receipt of claim.

Code of Federal Regulations, 2013 CFR

2013-07-01

... in any other format, shall be scanned into a computer and uploaded onto the TSCA database so that it... Medicine, Armed Forces Institute of Pathology, 1335 E. West Highway, #6-100, Silver Spring, MD 20910-6254...

Detail view in caryatid breezeway to show entrance steps; lion ...

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

Detail view in caryatid breezeway to show entrance steps; lion statues once flanked these steps - National Park Seminary, Aloha House, North of Linden Lane near corner of Beech Drive, Silver Spring, Montgomery County, MD

Close view of the two pavilions and causeway; note Japanese ...

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

Close view of the two pavilions and causeway; note Japanese Pagoda in background and causeway extension to the Swiss Chalet - National Park Seminary, Chateau Causeways, Between Linden Lane & Beach Drive, Silver Spring, Montgomery County, MD

Perspective view of the Indian Mission looking from approximately the ...

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

Perspective view of the Indian Mission looking from approximately the same vantage point as that seen in MD-1109-N-12 - National Park Seminary, Indian Mission, 2790 Linden Lane, Silver Spring, Montgomery County, MD

Closer view looking southeast along section of causeway between Ament ...

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

Closer view looking southeast along section of causeway between Ament Hall and the Music Hall with the two pavilions - National Park Seminary, Chateau Causeways, Between Linden Lane & Beach Drive, Silver Spring, Montgomery County, MD

View looking from the west to the end pavilion and ...

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

View looking from the west to the end pavilion and terminus of causeway at the Music Hall, with scale - National Park Seminary, Chateau Causeways, Between Linden Lane & Beach Drive, Silver Spring, Montgomery County, MD

Interior view, room 1103, view looking from the southeast to ...

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

Interior view, room 1103, view looking from the southeast to fireplace and mantel and inglenook, with scale - National Park Seminary, Music Hall, Linden Lane at western edge of campus, Silver Spring, Montgomery County, MD

1. Historic American Buildings Survey E. W. Russell, Photographer, September ...

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

1. Historic American Buildings Survey E. W. Russell, Photographer, September 15, 1936 GATE IN FRONT OF 201 GOVERNMENT STREET - 201 Government Street (Iron Gate), Moved to Spring Hill Avenue & Riviere du Chin Road, Mobile, Mobile County, AL

77 FR 14776 - El Paso Natural Gas Company; Notice of Amendment to Presidential Permit

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-13

... Natural Gas Company (El Paso), P.O. Box 1087, Colorado Springs, Colorado, filed an application in Docket..., Director, Regulatory Affairs, El Paso Western Pipelines, Two North Nevada Avenue, P.O. Box 1087, Colorado...

Development and recovery from winter embolism in silver birch: seasonal patterns and relationships with the phenological cycle in oceanic Scotland.

PubMed

Strati, Sara; Patiño, Sandra; Slidders, Caley; Cundall, Edward P; Mencuccini, Maurizio

2003-07-01

Silver birch (Betula pendula Roth) is increasingly used in the United Kingdom for reforestation. However, recent evidence indicates that, under some circumstances, planted birch can suffer serious and repeated mortality of the apical leaders and branches, with consequent loss of apical dominance and the formation of a contorted stem. Plants from 37 seed sources of silver birch from Scotland and northern England planted at two sites were compared for several characteristics related to hydraulic architecture, vulnerability to freeze-thaw cycle induced embolism and spring recovery from winter embolism during the period 2000-2002. Phenological rhythms were also monitored in late winter-early spring to document relationships between phenology and water relations parameters. Significant differences were found across seed sources in stage of bud flushing for four dates in spring. Early flushing seed sources differed by about 1 to 2 weeks from late-flushing seed sources across the two sites. Wintertime xylem embolism in stems reached a peak of about 50 to 70% loss of xylem hydraulic conductivity, depending on the size and position of the sample shoots in the canopy. Small apical shoots were significantly more embolized than large basal shoots. Development of winter embolism was coupled to the occurrence of frost events. As percent loss of hydraulic conductivity increased during the winter, wood relative water content declined. Embolism reversal occurred rapidly in spring at the time of development of positive root pressure. No significant differences in the degree of winter embolism in 2001 were found among the three seed sources examined. The investigation was expanded in the winter-spring of 2002 to include 10 seed sources across both sites. Significant differences were found in degree of winter embolism across sites, dates and seed sources. For each date, there was a significant relationship between flushing scores and wood relative water contents across the two sites and all seed sources, suggesting that differences in time of flushing across sites and seed sources were likely caused by differences in the time of occurrence of root pressure, a necessary precondition to flushing.

Interior view, detail to show typical bracket with gold leaf ...

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

Interior view, detail to show typical bracket with gold leaf ornament, here the bracket is located the north of the speaker on the second floor - National Park Seminary, Ballroom, Linden Lane, Silver Spring, Montgomery County, MD

77 FR 60679 - Takes of Marine Mammals Incidental to Specified Activities; U.S. Navy Training and Testing...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-04

...; the Undersea Warfare Training Range; the Key West Range Complex; the Naval Surface Warfare Center... of Protected Resources, National Marine Fisheries Service, 1315 East-West Highway, Silver Spring, MD...

Duplicate view to show interior of the gymnasium from approximately ...

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

Duplicate view to show interior of the gymnasium from approximately the same vantage point as in MD-1109-S-12 - National Park Seminary, Gymnasium, North of Linden Lane, south of Aloha House, Silver Spring, Montgomery County, MD

Interior view, general view in covered causeway (MD1109W) near ward ...

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

Interior view, general view in covered causeway (MD-1109-W) near ward 114, looking from the northwest - National Park Seminary, Music Hall, Linden Lane at western edge of campus, Silver Spring, Montgomery County, MD

76 FR 7155 - Atlantic Highly Migratory Species; Announcement of Billfish and Swordfish Catch Card Pilot...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-09

... Office of Science and Technology, 1315 East West Highway, Silver Spring, MD 20910. FOR FURTHER... landings information. Marinas, tackle shops and other private businesses will be asked to serve as catch...

Project on Elite Athlete Commitment (PEAK): III. An examination of the external validity across gender, and the expansion and clarification of the Sport Commitment Model.

PubMed

Scanlan, Tara K; Russell, David G; Magyar, T Michelle; Scanlan, Larry A

2009-12-01

The Sport Commitment Model was further tested using the Scanlan Collaborative Interview Method to examine its generalizability to New Zealand's elite female amateur netball team, the Silver Ferns. Results supported or clarified Sport Commitment Model predictions, revealed avenues for model expansion, and elucidated the functions of perceived competence and enjoyment in the commitment process. A comparison and contrast of the in-depth interview data from the Silver Ferns with previous interview data from a comparable elite team of amateur male athletes allowed assessment of model external validity, tested the generalizability of the underlying mechanisms, and separated gender differences from discrepancies that simply reflected team or idiosyncratic differences.

76 FR 74777 - National Marine Protected Areas Center External Review

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-01

... through targeted science, information resources, coordination and policy development. An external review..., 1305 East-West Highway, Rm. 11401, Silver Spring, Maryland 20910. FOR FURTHER INFORMATION CONTACT....mpa.gov SUPPLEMENTARY INFORMATION: The MPA Center's external review will encompass program activities...

76 FR 20689 - Guidance for Industry on Influenza: Developing Drugs for Treatment and/or Prophylaxis; Availability

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-13

... Hampshire Ave., Bldg. 51, rm. 2201, Silver Spring, MD 20993-0002. Send one self-addressed adhesive label to... exploration and verification of drug effects under epidemic and pandemic conditions. A draft notice of...

Perspective view looking from the east to the east northeast ...

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

Perspective view looking from the east to the east northeast facade, with Swiss Chalet in background, to replicate the view shown in MD-1109-J-18 - National Park Seminary, Japanese Pagoda, 2805 Linden Lane, Silver Spring, Montgomery County, MD

View looking along the northeast side of the causeway from ...

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

View looking along the northeast side of the causeway from vicinity of the Chalet extension to the pavilions and terminus at the Music Hall - National Park Seminary, Chateau Causeways, Between Linden Lane & Beach Drive, Silver Spring, Montgomery County, MD

Macroinvertebrate communities evaluated prior to and following a channel restoration project in Silver Creek, Blaine County, Idaho, 2001-16

USGS Publications Warehouse

MacCoy, Dorene E.; Short, Terry M.

2017-11-22

The U.S. Geological Survey, in cooperation with Blaine County and The Nature Conservancy, evaluated the status of macroinvertebrate communities prior to and following a channel restoration project in Silver Creek, Blaine County, Idaho. The objective of the evaluation was to determine whether 2014 remediation efforts to restore natural channel conditions in an impounded area of Silver Creek caused declines in local macroinvertebrate communities. Starting in 2001 and ending in 2016, macroinvertebrates were sampled every 3 years at two long-term trend sites and sampled seasonally (spring, summer, and autumn) in 2013, 2015, and 2016 at seven synoptic sites. Trend-site communities were collected from natural stream-bottom substrates to represent locally established macroinvertebrate assemblages. Synoptic site communities were sampled using artificial (multi-plate) substrates to represent recently colonized (4–6 weeks) assemblages. Statistical summaries of spatial and temporal patterns in macroinvertebrate taxonomic composition at both trend and synoptic sites were completed.The potential effect of the restoration project on resident macroinvertebrate populations was determined by comparing the following community assemblage metrics:Total taxonomic richness (taxa richness);Total macroinvertebrate abundance (total abundance);Ephemeroptera, Plecoptera, Trichoptera (EPT) richness;EPT abundance;Simpson’s diversity; andSimpson’s evenness for periods prior to and following restoration.A significant decrease in one or more metric values in the period following stream channel restoration was the basis for determining impairment to the macroinvertebrate communities in Silver Creek.Comparison of pre-restoration (2001–13) and post‑restoration (2016) macroinvertebrate community composition at trend sites determined that no significant decreases occurred in any metric parameter for communities sampled in 2016. Taxa and EPT richness of colonized assemblages at synoptic sites increased significantly from pre-restoration in 2013 to post-restoration in 2015 and 2016. Similarly, total and EPT abundances at synoptic sites showed non-significant increases from 2013 to 2015 and 2016. Significant seasonal differences in macroinvertebrate assemblages were apparent at synoptic site locations and likely reflected typical life-history patterns of increased insect emergence and development in the late spring and early summer months. Taxa and EPT richness were each significantly higher in spring and summer than in autumn, and total abundances were significantly higher in spring than in summer and autumn. No significant differences in community diversity or evenness of colonized communities were noted at synoptic site locations between pre- and post-restoration years or among seasons. Select community-metric results from the trend- and synoptic‑site sampling indicated that the Silver Creek restoration effort in 2014 did not result in a significant decline in resident macroinvertebrate communities.

State of STEM (SoSTEM) Address

NASA Image and Video Library

2014-01-29

Dr. John P. Holdren, Assistant to the President for Science and Technology and Director of the White House Office of Science & Technology Policy, left, is interviewed by Montgomery Blair High School Student Newspaper “Silver Chips” Online Editor-in-Chief Aanchal Johri, center, and Photo Editor Emma Howells, from Silver Spring, MD. ahead of the annual White House State of Science, Technology, Engineering, and Math (SoSTEM) address, Wednesday, Jan. 29, 2014, in the South Court Auditorium in the Eisenhower Executive Office Building on the White House complex in Washington. Photo Credit: (NASA/Bill Ingalls)

6. Historic American Buildings Survey E. W. Russell, Photographer, Feb. ...

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

6. Historic American Buildings Survey E. W. Russell, Photographer, Feb. 12, 1937 VIEW LOOKING UP MAIN DRIVEWAY SHOWING SO. E. (UPPER PORTION) OF BLDG. ALSO WEST ELEV. OF CHURCH. - Convent of the Visitation, 2300 Spring Hill Avenue, Mobile, Mobile County, AL

MX Siting Investigation. MX System Siting Summary Report. General Introduction. Volume I. Part I.

DTIC Science & Technology

1982-01-18

Mountain Spring Peak 1972 Observation Knoll 1971 Pinto Spring 1971 Steamboat Mountain 1971 Steamboat Mountain SW 1971 The Tetons 1971 Zane 1972 MX SITING...Silver Peak 1978 Stoddard Mountain 1978 Water Creek Canyon 1972 Yale Crossing 1971 49 Beaver Dam Mountains NE 1955 Central East 1972 Central West 1972...SHELTER SITE -ORIGINAL ROAD --- RESITED ROAD *• = FOUND 3 1/2" BRASS CAP SET ON 2 1/2" IRON PIPE . U.S DEPARTMENT OF THE INTERIOR. BUREAU OF LAND

Tree species preferences of foraging songbirds during spring migration in floodplain forests of the Upper Mississippi River

USGS Publications Warehouse

Kirsch, Eileen M.; Wellik, Mike J.

2017-01-01

Floodplain forest of the Upper Mississippi River is important for songbirds during spring migration. However, the altered hydrology of this system and spread of reed canary grass (Phalaris arundinacea) and emerald ash borer (Agrilus planipennis) threaten tree diversity and long-term sustainability of this forest. We estimated tree preferences of songbirds during spring migration 2010–2013 to help guide management decisions that promote tree diversity and forest sustainability and to evaluate yearly variation in tree selection. We used the point center-quarter method to assess relative availability of tree species and tallied bird foraging observations on tree species as well as recording the phenophase of used trees on five 40 ha plots of contiguous floodplain forest between La Crosse, Wisconsin and New Albin, Iowa, from 15 April through 1 June. We quantified bird preferences by comparing proportional use of tree species by each bird species to estimates of tree species availability for all 4 y and for each year separately. Species that breed locally preferred silver maple (Acer saccharinum), which is dominant in this forest. The common transient migrant species and the suite of 17 transient wood warbler species preferred hackberry (Celtis occidentalis) and oaks (Quercus spp.), which are limited to higher elevations on the floodplain. We observed earlier leaf development the warm springs of 2010 and 2012 and later leaf development the cold springs of 2011 and 2013. Yellow-rumped Warbler (Setophaga coronata), American Redstart (S. ruticilla), Warbling Vireo (Vireo gilvus) and Baltimore Oriole (Icterus galbula), and the suite of transient migrant wood warblers spread their foraging efforts among tree species in colder springs and were more selective in warmer springs. All three of the important tree species are not regenerating well on the UMR and widespread die-off of silver maple is possible in 50 y without large scale management.

Water-quality trends for selected sampling sites in the upper Clark Fork Basin, Montana, water years 1996-2010

USGS Publications Warehouse

Sando, Steven K.; Vecchia, Aldo V.; Lorenz, David L.; Barnhart, Elliott P.

2014-01-01

A large-scale trend analysis was done on specific conductance, selected trace elements (arsenic, cadmium, copper, iron, lead, manganese, and zinc), and suspended-sediment data for 22 sites in the upper Clark Fork Basin for water years 1996–2010. Trend analysis was conducted by using two parametric methods: a time-series model (TSM) and multiple linear regression on time, streamflow, and season (MLR). Trend results for 1996–2010 indicate moderate to large decreases in flow-adjusted concentrations (FACs) and loads of copper (and other metallic elements) and suspended sediment in Silver Bow Creek upstream from Warm Springs. Deposition of metallic elements and suspended sediment within Warm Springs Ponds substantially reduces the downstream transport of those constituents. However, mobilization of copper and suspended sediment from floodplain tailings and stream banks in the Clark Fork reach from Galen to Deer Lodge is a large source of metallic elements and suspended sediment, which also affects downstream transport of those constituents. Copper and suspended-sediment loads mobilized from within this reach accounted for about 40 and 20 percent, respectively, of the loads for Clark Fork at Turah Bridge (site 20); whereas, streamflow contributed from within this reach only accounted for about 8 percent of the streamflow at Turah Bridge. Minor changes in FACs and loads of copper and suspended sediment are indicated for this reach during 1996–2010. Clark Fork reaches downstream from Deer Lodge are relatively smaller sources of metallic elements than the reach from Galen to Deer Lodge. In general, small decreases in loads and FACs of copper and suspended sediment are indicated for Clark Fork sites downstream from Deer Lodge during 1996–2010. Thus, although large decreases in FACs and loads of copper and suspended sediment are indicated for Silver Bow Creek upstream from Warm Springs, those large decreases are not translated to the more downstream reaches largely because of temporal stationarity in constituent transport relations in the Clark Fork reach from Galen to Deer Lodge. Unlike metallic elements, arsenic (a metalloid element) in streams in the upper Clark Fork Basin typically is mostly in dissolved phase, has less variability in concentrations, and has weaker direct relations with suspended-sediment concentrations and streamflow. Arsenic trend results for 1996–2010 indicate generally moderate decreases in FACs and loads in Silver Bow Creek upstream from Opportunity. In general, small temporal changes in loads and FACs of arsenic are indicated for Silver Bow Creek and Clark Fork reaches downstream from Opportunity during 1996–2010. Contribution of arsenic (from Warm Springs Ponds, the Mill-Willow bypass, and groundwater sources) in the Silver Bow Creek reach from Opportunity to Warm Springs is a relatively large source of arsenic. Arsenic loads originating from within this reach accounted for about 11 percent of the load for Clark Fork at Turah Bridge; whereas, streamflow contributed from within this reach only accounted for about 2 percent of the streamflow at Turah Bridge.

Recent Update on MODIS/VIIRS Deep Blue Data Continuity and New Aerosol Products

NASA Technical Reports Server (NTRS)

Hsu, N. Christina; Sayer, Andrew M.; Lee, Jaehwa; Bettenhausen, Corey; Carletta, N.; Tsay, Si-Chee

2016-01-01

The MODIS VIIRS 2016 Science Team Meeting was held June 6-10, 2016 at the Sheraton in Silver Spring, MD. The organizers plan to post the presentations and posters here: http:modis.gsfc.nasa.govsci_teammeetings201606.

75 FR 77616 - Marine Mammals

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-13

... Education Division, Office of Protected Resources, NMFS, 1315 East-West Highway, Room 13705, Silver Spring... be submitted to the Chief, Permits, Conservation and Education Division, at the address listed above... public hearing should submit a written request to the Chief, Permits, Conservation and Education Division...

1. GENERAL VIEW OF CROSS ROW BUILDING (in background), LOOKING ...

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

1. GENERAL VIEW OF CROSS ROW BUILDING (in background), LOOKING SOUTHWEST. The building at right is Brick Row (Old Beersheba Inn, Brick Row, HABS No. TN-54 B) - Old Beersheba Inn, Cross Row (Boarding Cabin), Armsfield Avenue, Beersheba Springs, Grundy County, TN

13. Photocopy of drawing (original in possession of Naval Surface ...

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

13. Photocopy of drawing (original in possession of Naval Surface Warfare Center Carderock Division, Bethesda, MD) WIND TUNNEL BUILDING, ELEVATIONS, 1941 - Naval Surface Warfare Center, Subsonic Wind Tunnel Building, Bounded by Clara Barton Parkway & McArthur Boulevard, Silver Spring, Montgomery County, MD

75 FR 53665 - Hydrographic Services Review Panel Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-01

..., National Ocean Service (NOS), NOAA (N/CS), 1315 East West Highway, Silver Spring, Maryland 20910; Telephone... Review Panel Meeting AGENCY: National Ocean Service, National Oceanic and Atmospheric Administration..., National Ocean Service, National Oceanic and Atmospheric Administration. [FR Doc. 2010-21882 Filed 8-31-10...

15 CFR 922.50 - Appeals of administrative action.

Code of Federal Regulations, 2010 CFR

2010-01-01

... (Continued) NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE OCEAN AND COASTAL... Administrator for Ocean Services and Coastal Zone Management, NOAA 1305 East-West Highway, 13th Floor, Silver Spring, MD 20910. (c)(1) The Assistant Administrator may request the appellant to submit such information...

15 CFR 922.50 - Appeals of administrative action.

Code of Federal Regulations, 2011 CFR

2011-01-01

... (Continued) NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE OCEAN AND COASTAL... Administrator for Ocean Services and Coastal Zone Management, NOAA 1305 East-West Highway, 13th Floor, Silver Spring, MD 20910. (c)(1) The Assistant Administrator may request the appellant to submit such information...

77 FR 64491 - National Climate Assessment and Development Advisory Committee (NCADAC)

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-22

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Climate Assessment... National Climate Assessment and Development Advisory Committee (NCADAC). Time and Date: The meeting will be... One Veterans Place Silver Spring, MD 20910. Please check the National Climate Assessment Web site for...

76 FR 76386 - Marine Mammals; File No. 14241, Correction

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-07

... Resources, NMFS, 1315 East-West Highway, Room 13705, Silver Spring, MD 20910; phone (301) 427-8401; fax (301) 713-0376; Northeast Region, NMFS, 55 Great Republic Drive, Gloucester, MA 01930; phone (978) 281-9300...; phone (727) 824-5312; fax (727) 824-5309. [[Page 76387

South Dakota Air National Guard Joe Foss Field, Sioux Falls, SD. Remedial Investigation

DTIC Science & Technology

1990-09-01

obtaining a National Pollutant Discharge Elimination System (NPDES) permit relative to the remedial actions for groundwater treatment at Site 1...I Water samples are collected from these locations on a monthly basis and analyzed for conventional, inorganic, and bacteriological pollutants (fecal...cadmium, arsenic, and silver in the Big Sioux River at North Cliff Avenue just below the water treatment plant , approximately 1 mile east of the Base

78 FR 39004 - Federal Property Suitable as Facilities To Assist the Homeless

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-28

... following addresses: AIR FORCE: Mr. Robert Moore, Air Force Real Property Agency, 2261 Hughes Avenue, Suite... 304 Cheyenne Mountain AFS Colorado Springs CO 80914 Landholding Agency: Air Force Property Number... Agency: Air Force Property Number: 18201320042 Status: Underutilized Directions: 1478, 1479, 1480,1482...

Mineral resource of the month: mercury

USGS Publications Warehouse

Brooks, William E.

2006-01-01

The ore of mercury, cinnabar, is soft and dark red, and native mercury is one of a few metals that is liquid at room temperatures. Cinnabar from Almaden, Spain, the world’s oldest producing mercury mine, was used during Roman times, and the chemical symbol for mercury (Hg) is from "hydrargyrum," from the Greek word meaning liquid silver. Cinnabar and mercury are associated with some hydrothermal mineral deposits and occur in fine-grained or sedimentary and volcanic rocks near hot springs or volcanic centers. Mercury may be recovered as a byproduct of processing copper, gold, lead-zinc or silver.

Temperature Coefficient of the Modulus of Rigidity of Aircraft Instrument Diaphragm and Spring Materials

NASA Technical Reports Server (NTRS)

Brombacher, W G; Melton, E R

1931-01-01

Experimental data are presented on the variation of the modulus of rigidity in the temperature range -20 to +50 degrees C. of a number of metals which are of possible use for elastic elements for aircraft and other instruments. The methods of the torsional pendulum was used to determine the modulus of rigidity and its temperature coefficient for aluminum, duralumin, monel metal, brass, phosphor bronze, coin silver, nickel silver, three high carbon steels, and three alloy steels. It was observed that tensile stress affected the values of the modulus by amounts of 1 per cent or less.

Fabrication Studies of Ternary Rare Earth Sulfides for Infrared Applications.

DTIC Science & Technology

1982-05-01

crystal growth by vapor transport. The objective was to achieve small , high purity, theoretically dense crystals for optical property characterization...Weapons Center White Oak Silver Spring MD 20910 Dr. S. Musikant General Electric Co - RESD 3198 Chestnut Street Philadelphia PA 19101 Dr. W. White

10. Photocopy of drawing (original in possession of Naval Surface ...

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

10. Photocopy of drawing (original in possession of Naval Surface Warfare Center Carderock Division, Bethesda, MD) SUPERSONIC WIND TUNNEL BUILDING, GROUND FLOOR PLAN, 1947 - Naval Surface Warfare Center, Supersonic Wind Tunnel Building, Bounded by Clara Barton Parkway & McArthur Boulevard, Silver Spring, Montgomery County, MD

14. Photocopy of drawing (original in possession of Naval Surface ...

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

14. Photocopy of drawing (original in possession of Naval Surface Warfare Center Carderock Division, Bethesda, MD) WIND TUNNEL, FRAMING PLAN, TOP AND BOTTOM, 1941 - Naval Surface Warfare Center, Subsonic Wind Tunnel Building, Bounded by Clara Barton Parkway & McArthur Boulevard, Silver Spring, Montgomery County, MD

78 FR 41034 - Endangered Species; File No. 18102

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-09

... must be received at the appropriate address or fax number (see ADDRESSES) on or before August 8, 2013... also available upon written request or by appointment in the following office: Endangered Species Conservation Division, Office of Protected Resources, NMFS, 1315 East-West Highway, Room 13535, Silver Spring...

76 FR 65736 - Oncologic Drugs Advisory Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-24

.... 1503), Silver Spring, MD 20993-0002. Information regarding special accommodations due to a disability... appropriate advisory committee hot line/phone line to learn about possible modifications before coming to the... accommodate persons with physical disabilities or special needs. If you require special accommodations due to...

77 FR 20793 - Marine Mammals; File No. 16599

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-06

...-2200; fax (808) 973-2941; Northeast Region, NMFS, 55 Great Republic Drive, Gloucester, MA 01930; phone... Drive, 200, San Diego, CA 92106, to conduct scientific research on cetaceans stranded or in... of Protected Resources, NMFS, 1315 East-West Highway, Room 13705, Silver Spring, MD 20910; phone (301...

The AMATYC Review, Volume 18, Numbers 1-2, Fall 1996-Spring 1997.

ERIC Educational Resources Information Center

Browne, Joseph, Ed.

1997-01-01

Designed as an avenue of communication for mathematics educators concerned with the views, ideas, and experiences of two-year college students and teachers, this journal contains articles on mathematics exposition and education and regular features presenting book and software reviews, classroom activities, instructor experiences, and math…

The AMATYC Review, Volume 17. Numbers 1-2, Fall 1995-Spring 1996.

ERIC Educational Resources Information Center

Browne, Joseph, Ed.

1996-01-01

Designed as an avenue of communication for mathematics educators concerned with the views, ideas, and experiences of two-year college students and teachers, this journal contains articles on mathematics exposition and education and regular features presenting book and software reviews, classroom activities, instructor experiences, and math…

75 FR 50751 - Notice of Availability of Government-Owned Inventions; Available for Licensing

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-17

... CFR part 404. Applications will be evaluated utilizing the following criteria: (1) Ability to... CONTACT: Dr. Charles Schlagel, Director, Office of Technology Transfer, Naval Medical Research Center, 503 Robert Grant Ave., Silver Spring, MD 20910-7500, telephone 301-319-7428 or e-mail at: charles.schlagel...

78 FR 14985 - Takes of Marine Mammals Incidental to Specified Activities; Russian River Estuary Management...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-08

...: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce..., Office of Protected Resources, National Marine Fisheries Service, 1315 East-West Highway, Silver Spring... deny the authorization and publish notice in the Federal Register of issuance or denial within 30 days...

78 FR 44574 - Third Annual Food and Drug Administration Health Professional Organizations Conference

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-24

... . Contact: Brenda Rose, Office of Special Health Issues, 10903 New Hampshire Ave., Silver Spring, MD 20993... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2013-N-0001] Third Annual Food and Drug Administration Health Professional Organizations Conference AGENCY: Food and...

12. Photocopy of drawing (original in possession of Naval Surface ...

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

12. Photocopy of drawing (original in possession of Naval Surface Warfare Center Carderock Division, Bethesda, MD) SUPERSONIC WIND TUNNEL, STEEL VACUUM SPHERE, FOUNDATION PLAN, ELEVATION AND DETAILS, 1947 - Naval Surface Warfare Center, Supersonic Wind Tunnel Building, Bounded by Clara Barton Parkway & McArthur Boulevard, Silver Spring, Montgomery County, MD

23. Photocopy of drawing (original in possession of Naval Surface ...

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

23. Photocopy of drawing (original in possession of Naval Surface Warfare Center Carderock Division, Bethesda, MD) 7 X 10 FOOT SONIC WIND TUNNEL, FAN HOUSING ASSEMBLY, 1952 - Naval Surface Warfare Center, Transonic Wind Tunnel Building, Bounded by Clara Barton Parkway & McArthur Boulevard, Silver Spring, Montgomery County, MD

9. Photocopy of photograph (original photograph in the collection of ...

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

9. Photocopy of photograph (original photograph in the collection of Naval Surface Warfare Center Carderock Division, Bethesda, MD) VIEW SOUTH, SUPERSONIC WIND TUNNEL TEST SECTION, ca 1950 - Naval Surface Warfare Center, Supersonic Wind Tunnel Building, Bounded by Clara Barton Parkway & McArthur Boulevard, Silver Spring, Montgomery County, MD

10. Photocopy of photograph (original photograph in the collection of ...

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

10. Photocopy of photograph (original photograph in the collection of Naval Surface Warfare Center Carderock Division, Bethesda, MD) VIEW SOUTHWEST, SUBSONIC WIND TUNNEL BUILDING, 1943 - Naval Surface Warfare Center, Subsonic Wind Tunnel Building, Bounded by Clara Barton Parkway & McArthur Boulevard, Silver Spring, Montgomery County, MD

19. Photocopy of drawing (original In possession of Naval Surface ...

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

19. Photocopy of drawing (original In possession of Naval Surface Warfare Center Carderock Division, Bethesda, MD) 7 X 10 FOOT SONIC WIND TUNNEL PLOT AND GRADING PLAN, 1952 - Naval Surface Warfare Center, Transonic Wind Tunnel Building, Bounded by Clara Barton Parkway & McArthur Boulevard, Silver Spring, Montgomery County, MD

21. Photocopy of drawing (original in possession of Naval Surface ...

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

21. Photocopy of drawing (original in possession of Naval Surface Warfare Center Carderock Division, Bethesda, MD) 7 X 10 FOOT SONIC WIND TUNNEL, LABORATORY AND OFFICE BUILDING, 1950 - Naval Surface Warfare Center, Transonic Wind Tunnel Building, Bounded by Clara Barton Parkway & McArthur Boulevard, Silver Spring, Montgomery County, MD

12. Photocopy of drawing (original in possession of Naval Surface ...

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

12. Photocopy of drawing (original in possession of Naval Surface Warfare Center Carderock Division, Bethesda, MD) WIND TUNNEL BUILDING, FIRST FLOOR PLAN, NOTE OPEN SHOP, 1941 - Naval Surface Warfare Center, Subsonic Wind Tunnel Building, Bounded by Clara Barton Parkway & McArthur Boulevard, Silver Spring, Montgomery County, MD

11. Photocopy of drawing (original in possession of Naval Surface ...

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

11. Photocopy of drawing (original in possession of Naval Surface Warfare Center Carderock Division, Bethesda, MD) SUPERSONIC WIND TUNNEL BUILDING, SECTIONS AND DETAILS, MECHANICAL, 1947 - Naval Surface Warfare Center, Supersonic Wind Tunnel Building, Bounded by Clara Barton Parkway & McArthur Boulevard, Silver Spring, Montgomery County, MD

11. Photocopy of photograph (original photograph In the collection of ...

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

11. Photocopy of photograph (original photograph In the collection of Naval Surface Warfare Center Carderock Division, Bethesda, MD) VIEW NORTHEAST, INTERIOR, SUBSONIC WIND TUNNEL FAN ASSEMBLY, 1943 - Naval Surface Warfare Center, Subsonic Wind Tunnel Building, Bounded by Clara Barton Parkway & McArthur Boulevard, Silver Spring, Montgomery County, MD

76 FR 82310 - Cardiovascular and Renal Drugs Advisory Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-30

... (Parkinson's Disease, Multiple System Atrophy, and Pure Autonomic Failure), Dopamine Beta-Hydroxylase... recommendations to the Agency on FDA's regulatory issues. Date and Time: The meeting will be held on February 23... Colesville Rd., Silver Spring, MD 20910. The hotel's telephone number is (301) 589-5200. Contact Person...

75 FR 43929 - National Weather Service (NWS) Strategic Plan, 2011-2020

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-27

... management, and private sector, research and operations partners. NWS invites comments on the contents of... 18234, Silver Spring, Maryland 20910. E-mail comments to nws.great.ideas@noaa.gov . NWS prefers that... prediction and monitoring. NOAA's commitment to science, service, and stewardship informs society to respond...

21 CFR 312.145 - Guidance documents.

Code of Federal Regulations, 2014 CFR

2014-04-01

... HUMAN USE INVESTIGATIONAL NEW DRUG APPLICATION Miscellaneous § 312.145 Guidance documents. (a) FDA has... of Drug Information, Center for Drug Evaluation and Research, Food and Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD 20993-0002. A request for a copy of the CBER list should be directed to...

21 CFR 312.145 - Guidance documents.

Code of Federal Regulations, 2013 CFR

2013-04-01

... HUMAN USE INVESTIGATIONAL NEW DRUG APPLICATION Miscellaneous § 312.145 Guidance documents. (a) FDA has... of Drug Information, Center for Drug Evaluation and Research, Food and Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD 20993-0002. A request for a copy of the CBER list should be directed to...

21 CFR 807.37 - Inspection of establishment registration and device listings.

Code of Federal Regulations, 2012 CFR

2012-04-01

... Administration, Center for Devices and Radiological Health, Office of Compliance, 10903 New Hampshire Ave., Bldg... Drug Administration, Center for Devices and Radiological Health, Office of Compliance, 10903 New Hampshire Ave., Bldg. 66, rm. 3521, Silver Spring, MD 20993-0002. In addition, there will be available for...

21 CFR 312.145 - Guidance documents.

Code of Federal Regulations, 2012 CFR

2012-04-01

... HUMAN USE INVESTIGATIONAL NEW DRUG APPLICATION Miscellaneous § 312.145 Guidance documents. (a) FDA has... of Drug Information, Center for Drug Evaluation and Research, Food and Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD 20993-0002. A request for a copy of the CBER list should be directed to...

21 CFR 312.145 - Guidance documents.

Code of Federal Regulations, 2011 CFR

2011-04-01

... HUMAN USE INVESTIGATIONAL NEW DRUG APPLICATION Miscellaneous § 312.145 Guidance documents. (a) FDA has... of Drug Information, Center for Drug Evaluation and Research, Food and Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD 20993-0002. A request for a copy of the CBER list should be directed to...

21 CFR 812.19 - Address for IDE correspondence.

Code of Federal Regulations, 2011 CFR

2011-04-01

... and Radiological Health, Document Mail Center, 10903 New Hampshire Ave., Bldg. 66, rm. G609, Silver Spring, MD 20993-0002. (2) For devices regulated by the Center for Biologics Evaluation and Research, send it to the Document Control Center (HFM-99), Center for Biologics Evaluation and Research, Food and...

78 FR 8496 - Marine Mammals; File No. 13927

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-06

..., Silver Spring, MD 20910; phone (301) 427-8401; fax (301) 713-0376; and Southeast Region, NMFS, 263 13th... INFORMATION CONTACT: Carrie Hubard or Amy Hapeman, (301) 427-8401. SUPPLEMENTARY INFORMATION: On May 10, 2012... (Tursiops truncatus) and Atlantic spotted dolphins (Stenella frontalis) may be incidentally harassed during...

Interior view to show inside of one of the three ...

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

Interior view to show inside of one of the three octagonal-shaped pavilions; note interior seating. View taken from beginning of the causeway just outside the Music Hall (MD-1109-G) - National Park Seminary, Chateau Causeways, Between Linden Lane & Beach Drive, Silver Spring, Montgomery County, MD

21 CFR 203.12 - An appeal from an adverse decision by the district office.

Code of Federal Regulations, 2010 CFR

2010-04-01

... to the Office of Compliance, Center for Drug Evaluation and Research, Food and Drug Administration... and Biologics Quality (HFM-600), Center for Biologics Evaluation and Research, Food and Drug... and Research, Food and Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD 20993-0002...

21 CFR 201.25 - Bar code label requirements.

Code of Federal Regulations, 2011 CFR

2011-04-01

... and Research, Food and Drug Administration, 10903 New Hampshire Ave., Bldg. 51, Silver Spring, MD...-600), Center for Biologics Evaluation and Research, Food and Drug Administration, 1401 Rockville Pike... 21 Food and Drugs 4 2011-04-01 2011-04-01 false Bar code label requirements. 201.25 Section 201.25...

21 CFR 203.12 - An appeal from an adverse decision by the district office.

Code of Federal Regulations, 2011 CFR

2011-04-01

... to the Office of Compliance, Center for Drug Evaluation and Research, Food and Drug Administration... and Biologics Quality (HFM-600), Center for Biologics Evaluation and Research, Food and Drug... and Research, Food and Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD 20993-0002...

15. Photocopy of drawing (original in possession of Naval Surface ...

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

15. Photocopy of drawing (original in possession of Naval Surface Warfare Center Carderock Division, Bethesda, MD) WIND TUNNEL, ELEVATIONS E-E TO H-H AND SECTIONS, 1941 - Naval Surface Warfare Center, Subsonic Wind Tunnel Building, Bounded by Clara Barton Parkway & McArthur Boulevard, Silver Spring, Montgomery County, MD

78 FR 49272 - Pediatric Advisory Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-13

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2013-N-0001.../maryland/doubletree-by-hilton-hotel-washington-dc-silver-spring-DCASSDT/index.html . Contact Person: Walter... Equity Act (Pub. L. 108-155). On September 19, 2013, the PAC will meet to discuss Cervarix (human...

The AMATYC Review, Fall 1992-Spring 1993.

ERIC Educational Resources Information Center

Cohen, Don, Ed.; Browne, Joseph, Ed.

1993-01-01

Designed as an avenue of communication for mathematics educators concerned with the views, ideas, and experiences of two-year college students and teachers, this journal contains articles on mathematics exposition and education, as well as regular features presenting book and software reviews and math problems. The first of two issues of volume 14…

Engineering Competition--A Win-Win Event for All

ERIC Educational Resources Information Center

Sweeney, Preston

2010-01-01

Hosting an engineering competition can bring great success to a technology department. Development and planning of an event can prove frustrating at times, but it pays off in the end. The author describes the first-ever engineering competition held at Maple Avenue Middle School in Saratoga Springs, New York, which provided an evening of creative…

The AMATYC Review, Volume 15, Numbers 1-2, Fall 1993-Spring 1994.

ERIC Educational Resources Information Center

Browne, Joseph, Ed.

1994-01-01

Designed as a avenue of communication for mathematics educators concerned with the views, ideas, and experiences of two-year college students and teachers, this journal contains articles on mathematics exposition and education, and regular features presenting book and software reviews and math problems. Volume 15 includes the following articles:…

The AMATYC Review, Fall 1987, Spring 1988.

ERIC Educational Resources Information Center

Cohen, Don, Ed.

1988-01-01

Designed as an avenue of communication for mathematics educators concerned with the views, ideas, and experiences of two-year college students and teachers, this journal contains articles on mathematics exposition and education, and regular features that present book and software reviews and math problems. The first of two issues of volume 9…

3. Historic American Buildings Survey E. W. Russell, Photographer, April ...

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

3. Historic American Buildings Survey E. W. Russell, Photographer, April 2, 1937 VIEW LOOKING S.W. SHOWING N.W. CORNER OF SECTION 'D' & 'E' ON THE RIGHT & NORTH ELEV. OF SMALL BUILDING WITH HALF OCTAGONAL BAYS ON LEFT. - Convent of the Visitation, 2300 Spring Hill Avenue, Mobile, Mobile County, AL

77 FR 52741 - Compliance Policy Guide Sec. 420.300 Changes in Compendial Specifications and New Drug...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-30

... Evaluation and Research, Food and Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD 20993, 301... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2012-N-0135... Supplements; Withdrawal of Guidance AGENCY: Food and Drug Administration, HHS. ACTION: Notice; withdrawal...

78 FR 27116 - Draft Guidance for Industry on Charging for Investigational Drugs Under an Investigational New...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-09

... Research, Food and Drug Administration, 10903 New Hampshire Ave., Bldg. 51, rm. 2201, Silver Spring, MD... Evaluation and Research, Food and Drug Administration, 1401 Rockville Pike, suite 200N, Rockville, MD 20852...: Colleen L. Locicero, Center for Drug Evaluation and Research, Food and Drug Administration, 10903 New...

15 CFR Appendix 1 to Part 960 - Filing Instructions and Information To Be Included in the Licensing Application

Code of Federal Regulations, 2010 CFR

2010-01-01

..., DEPARTMENT OF COMMERCE GENERAL REGULATIONS OF THE ENVIRONMENTAL DATA SERVICE LICENSING OF PRIVATE REMOTE... and Information Service (NESDIS), NOAA, Department of Commerce, 1335 East West Highway, Silver Spring... applicant's total indebtedness; (ix) A person upon who service of all documents may be made. (2) A...

15 CFR Appendix 1 to Part 960 - Filing Instructions and Information To Be Included in the Licensing Application

Code of Federal Regulations, 2011 CFR

2011-01-01

..., DEPARTMENT OF COMMERCE GENERAL REGULATIONS OF THE ENVIRONMENTAL DATA SERVICE LICENSING OF PRIVATE REMOTE... and Information Service (NESDIS), NOAA, Department of Commerce, 1335 East West Highway, Silver Spring... applicant's total indebtedness; (ix) A person upon who service of all documents may be made. (2) A...

77 FR 47652 - Second Annual Food and Drug Administration Health Professional Organizations Conference

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-09

... of Special Health Issues, Food and Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD... between health professional organizations and FDA staff. The Office of Special Health Issues serves as a... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2012-N-0001...

20. Photocopy of drawing (original in possession of Naval Surface ...

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

20. Photocopy of drawing (original in possession of Naval Surface Warfare Center Carderock Division, Bethesda, MD) 7 X 10 FOOT SONIC WIND TUNNEL FIRST FLOOR PLANS AND DETAILS, 1948 - Naval Surface Warfare Center, Transonic Wind Tunnel Building, Bounded by Clara Barton Parkway & McArthur Boulevard, Silver Spring, Montgomery County, MD

22. Photocopy of drawing (original in possession of Naval Surface ...

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

22. Photocopy of drawing (original in possession of Naval Surface Warfare Center Carderock Division, Bethesda, MD) 7 X 10 FOOT SONIC WIND TUNNEL, INSTALLATION OF POWER EQUIPMENT AND ACCESSORIES, 1950 - Naval Surface Warfare Center, Transonic Wind Tunnel Building, Bounded by Clara Barton Parkway & McArthur Boulevard, Silver Spring, Montgomery County, MD

75 FR 56055 - Advisory Committee and Species Working Group Technical Advisor Appointments

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-15

... Ms. Rachel O'Malley, Office of International Affairs, National Marine Fisheries Service, NOAA, Room..., Silver Spring, MD 20910. Nominations can also be provided via fax (301-713-2313) or e-mail ( Rachel.O'Malley@noaa.gov and [email protected] ). FOR FURTHER INFORMATION CONTACT: Keith Cialino, 301-713...

77 FR 43808 - Advisory Committee and Species Working Group Technical Advisor Appointment

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-26

... sent via email ( Rachel.O'Malley@noaa.gov ). In the alternative, nominations may be sent via mail to Rachel O'Malley at NMFS, Office of International Affairs, Room 12622, 1315 East-West Highway, Silver Spring, MD 20910. FOR FURTHER INFORMATION CONTACT: Rachel O'Malley, Office of International Affairs, 301...

75 FR 36099 - Medical Devices; Availability of Safety and Effectiveness Summaries for Premarket Approval...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-24

... of the availability of safety and effectiveness summaries of approved PMAs through the Internet and... New Hampshire Ave., Bldg. 66, rm. 1650, Silver Spring, MD 20993, 301-796- 6570. SUPPLEMENTARY... and denials in the Federal Register. Instead, the agency now posts this information on the Internet on...

78 FR 33071 - Marine Mammals; File No. 10018

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-03

..., Office of Protected Resources, NMFS, 1315 East-West Highway, Room 13705, Silver Spring, MD 20910; phone... effects of the permitted activities on the human environment was prepared in compliance with the National Environmental Policy Act of 1969 (42 U.S.C. 4321 et seq.). Based on the analyses in the SEA, NMFS determined...

78 FR 48655 - Marine Mammals; File No. 17324

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-09

... Protected Resources, NMFS, 1315 East-West Highway, Room 13705, Silver Spring, MD 20910; phone (301) 427-8401... prepared analyzing the effects of the proposed activities on the human environment in compliance with the National Environmental Policy Act of 1969 (42 U.S.C. 4321 et seq.). Based on the analyses in the EA, NMFS...

Small Child Care Facilities in Residential Areas.

ERIC Educational Resources Information Center

Giegerich & Associates, Inc., Rockville, MD.

One part of a three-part investigation prepared for the Montgomery County Planning Board in Silver Spring, Maryland, this study addresses planning and site planning issues arising from the location of child care facilities in residential settings. The study, which emphasizes homes and centers which care for 7 to 20 children, provides a detailed…

Temperature and Concentration Profiles in Hydrogen-Nitrous Oxide Flames.

DTIC Science & Technology

1986-07-01

SECumvY CLASSIFICATION CF TIS PAGOE(hn Date. 3.,OCO 20. Abstract (Cont’d): est for flame modeler UNCLASSIFIED * SECURITY CL ASSIrIC ATION Or THIS P...Commander Naval Surface Weapons Center Commander ATTN: R. Bernecker, R-13 US Army Tank Automotive G.B. Wilmot , R-16 Command Silver Spring, MD 20902

32 CFR 536.30 - Action upon receipt of claim.

Code of Federal Regulations, 2010 CFR

2010-07-01

... claimant, for example, husband and wife, injured parent and children. If only one sum is filed for all... Medicine, Armed Forces Institute of Pathology, 1335 E. West Highway, #6-100, Silver Spring, MD 20910-6254... recreational user or family child care provider forward a copy to: Army Central Insurance Fund, ATTN: CFSC-FM-I...

75 FR 55803 - Neurological Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-14

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2010-N-0001... Radiological Health, Food and Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD 20993, or FDA... the treatment of depression. FDA intends to make background material available to the public no later...

50 CFR 296.5 - Instructions for filing claims.

Code of Federal Regulations, 2011 CFR

2011-10-01

... first returns to a port after discovering the damage or loss. Filing of a fifteen-day report must be... which the vessel first returns to a port after discovering the damage or loss. Satisfaction of the... Fisheries Service, 1315 East-West Highway, Silver Spring, MD 20910; telephone: (301) 713-2396. (3) Contents...

Supreme Court Decision Could Help Efforts to Block Animal Research.

ERIC Educational Resources Information Center

Jaschik, Scott

1991-01-01

A decision in the case involving the "Silver Spring Monkeys" and National Institutes of Health research left open the possibility of suing the federal agency in state courts, possibly making it easier for animal-rights groups to block some animal research. However, the ruling addresses only a narrow jurisdictional question. (MSE)

76 FR 75551 - Draft Guidance for Industry on Regulatory Classification of Pharmaceutical Co-Crystals; Availability

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-02

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2011-D-0800... AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and Drug Administration (FDA... Research, Food and Drug Administration, 10903 New Hampshire Ave., Bldg. 51, rm. 2201, Silver Spring, MD...

Child Care Centers in Park Settings.

ERIC Educational Resources Information Center

Giegerich & Associates, Inc., Rockville, MD.

One of three studies of child care which addressed a variety of planning and site planning issues of concern to the Montgomery County Planning Board in Silver Spring, Maryland, this study reports findings related to the location of child care facilities in park settings. Principal purposes of the study were to: (1) analyze the community impact of…

View looking from northeast to southwest (generally) past the Music ...

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

View looking from northeast to southwest (generally) past the Music Hall, pavilions, and causeway extension to the north elevation of the Swiss Chalet; note Japanese Pagoda in background. View likely taken from beneath the Dog Bridge. - National Park Seminary, Chateau Causeways, Between Linden Lane & Beach Drive, Silver Spring, Montgomery County, MD

78 FR 66745 - Draft and Revised Draft Guidances for Industry Describing Product-Specific Bioequivalence...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-06

... Research, Food and Drug Administration, 10903 New Hampshire Ave., Bldg. 51, Rm. 2201, Silver Spring, MD...], Center for Drug Evaluation and Research (HFD-600), Food and Drug Administration, 7520 Standish Pl... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2007-D-0369...

78 FR 37230 - Draft and Revised Draft Guidances for Industry Describing Product-Specific Bioequivalence...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-20

... Research, Food and Drug Administration, 10903 New Hampshire Ave., Bldg. 51, Rm. 2201, Silver Spring, MD...], Center for Drug Evaluation and Research (HFD-600), Food and Drug Administration, 7519 Standish Pl... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2007-D-0369...

77 FR 19672 - Draft Guidances Relating to the Development of Biosimilar Products; Public Hearing; Request for...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-02

... Research, Food and Drug Administration, 10903 New Hampshire Ave., Bldg. 51, Rm. 6340, Silver Spring, MD... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2011-D-0618] Draft Guidances Relating to the Development of Biosimilar Products; Public Hearing; Request for Comments...

77 FR 74669 - Draft and Revised Draft Guidances for Industry Describing Product-Specific Bioequivalence...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-17

... Research, Food and Drug Administration, 10903 New Hampshire Ave., Bldg. 51, Rm. 2201, Silver Spring, MD...], Center for Drug Evaluation and Research (HFD-600), Food and Drug Administration, 7519 Standish Pl... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2007-D-0369...

75 FR 57803 - Preparation for International Conference on Harmonisation Steering Committee and Expert Working...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-22

... Hampshire Ave., Silver Spring, MD 20993-0002, email: [email protected] , or FAX: 301-595-7937... name, address, telephone, and fax number), written material, and requests to make oral presentations to... either hardcopy or on CD-ROM, after submission of a Freedom of Information request. Written requests are...

21 CFR 212.5 - To what drugs do the regulations in this part apply?

Code of Federal Regulations, 2010 CFR

2010-04-01

... requirements in parts 210 and 211 of this chapter. (b) Investigational and research PET drugs. For... part 312 of this chapter, and PET drugs produced with the approval of a Radioactive Drug Research... Drug Administration Biosciences Library, 10903 New Hampshire Ave., Silver Spring, MD, 20993-0002, 301...

77 FR 13562 - Marine Mammals; File No. 14241

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-07

..., 55 Great Republic Drive, Gloucester, MA 01930; phone (978) 281-9328; fax (978) 281-9394; and... Resources, NMFS, 1315 East-West Highway, Room 13705, Silver Spring, MD 20910; phone (301) 427-8401; fax (301...; phone (206) 526-6150; fax (206) 526-6426; Southwest Region, NMFS, 501 West Ocean Blvd., Suite 4200, Long...

75 FR 9161 - Marine Mammals; File No. 15153

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-01

... Quest Hawaii, 69-425 Waikoloa Beach Drive, Waikoloa, HI 96738 has been issued a permit to import two..., Silver Spring, MD 20910; phone (301) 713-2289; fax (301) 713-0376; and Pacific Islands Region, NMFS, 1601 Kapiolani Blvd., Rm 1110, Honolulu, HI 96814-4700; phone (808) 944-2200; fax (808) 973-2941. FOR FURTHER...

77 FR 19004 - Fishing Capacity Reduction Program for the Southeast Alaska Purse Seine Salmon Fishery

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-29

... Capacity Reduction Program for the Southeast Alaska Purse Seine Salmon Fishery AGENCY: National Marine... Salmon Fishery. DATES: Comments must be submitted on or before 5 p.m. EST April 13, 2012. ADDRESSES: Send... Seine Salmon Buyback, 1315 East-West Highway, Silver Spring, MD 20910 (see FOR FURTHER INFORMATION...

An evaluation and geochemical survey of the Farah Garan East Prospect, Southeast Asir, Kingdom of Saudi Arabia

USGS Publications Warehouse

Bookstrom, Arthur A.; El Komi, Mohamed; Christian, Ralph P.; Bazzari, Maher A.

1990-01-01

Ore minerals in outcrops, and geochemically anomalous concentrations of gold, silver, copper, lead, zinc, arsenic, antimony, and tellurium are present in carbonate-rich rocks of the hot-spring assemblage. This indicates that the ore minerals and elements were deposited originally as constituents of the hot-spring assemblage. However, exposed ore-mineral occurrences are small and sparse, and geochemical anomalies are small, irregularly distributed, and of subeconomic grade. Furthermore, weak electromagnetic anomalies do not indicate the presence of subsurface bodies of concentrated, conductive ore minerals. Therefore, no drilling is recommended.

Solution-processed parallel tandem polymer solar cells using silver nanowires as intermediate electrode.

PubMed

Guo, Fei; Kubis, Peter; Li, Ning; Przybilla, Thomas; Matt, Gebhard; Stubhan, Tobias; Ameri, Tayebeh; Butz, Benjamin; Spiecker, Erdmann; Forberich, Karen; Brabec, Christoph J

2014-12-23

Tandem architecture is the most relevant concept to overcome the efficiency limit of single-junction photovoltaic solar cells. Series-connected tandem polymer solar cells (PSCs) have advanced rapidly during the past decade. In contrast, the development of parallel-connected tandem cells is lagging far behind due to the big challenge in establishing an efficient interlayer with high transparency and high in-plane conductivity. Here, we report all-solution fabrication of parallel tandem PSCs using silver nanowires as intermediate charge collecting electrode. Through a rational interface design, a robust interlayer is established, enabling the efficient extraction and transport of electrons from subcells. The resulting parallel tandem cells exhibit high fill factors of ∼60% and enhanced current densities which are identical to the sum of the current densities of the subcells. These results suggest that solution-processed parallel tandem configuration provides an alternative avenue toward high performance photovoltaic devices.

Spatiotemporal associations between Pacific herring spawn and surf scoter spring migration: evaluating a "silver wave" hypothesis

USGS Publications Warehouse

Lok, E.K.; Esler, Daniel N.; Takekawa, John Y.; De La Cruz, S.W.; Boyd, W.S.; Nysewander, D.R.; Evenson, J.R.; Ward, D.H.

2012-01-01

Surf scoters Melanitta perspicillata are sea ducks that aggregate at spawning events of Pacific herring Clupea pallasi and forage on the eggs, which are deposited in abundance during spring at discrete sites. We evaluated whether migrating scoters followed a ‘silver wave’ of resource availability, analogous to the ‘green wave’ of high-quality foraging conditions that herbivorous waterfowl follow during spring migration. We confirmed that herring spawning activity began later in the year at higher latitudes, creating a northward-progressing wave of short-term localized food availability. Using satellite telemetry and aerial surveys, we documented the chronology of scoter spring migration and the use of stopover locations in relation to herring spawn timing and locations. We found that the migration chronology paralleled the northward progression of herring spawning events. Although there was considerable variability in the timing of both scoter migration and the initiation of herring spawning, the processes were related beyond a coincidental northward progression. During migration, 60% of the tracked scoters visited at least 1 spawn site, and those that used spawn sites were located on spawn sites for approximately one-third of their migration locations. Surf scoters showed close spatiotemporal associations with herring spawning events, confirming that the presence of herring spawn was a factor determining habitat use for many individuals. Surf scoters showed close spatiotemporal associations with herring spawning events, confirming that the presence of herring spawn was a factor determining habitat use for many individuals, a conclusion that is consistent with previous studies which used physiologically based metrics to evaluate the importance of herring spawn.

Trace-metal concentrations in sediment and water and health of aquatic macroinvertebrate communities of streams near Park City, Summit County, Utah

USGS Publications Warehouse

Giddings, Elis M.P.; Hornberger, Michelle I.; Hadley, Heidi K.

2001-01-01

The spatial distribution of metals in streambed sediment and surface water of Silver Creek, McLeod Creek, Kimball Creek, Spring Creek, and part of the Weber River, near Park City, Utah, was examined. From the mid-1800s through the 1970s, this region was extensively mined for silver and lead ores. Although some remediation has occurred, residual deposits of tailing wastes remain in place along large sections of Silver Creek. These tailings are the most likely source of metals to this system. Bed sediment samples were collected in 1998, 1999, and 2000 and analyzed using two extraction techniques: a total extraction that completely dissolves all forms of metals in minerals and trace elements associated with the sediment; and a weak-acid extraction that extracts the metals and trace elements that are only weakly adsorbed onto the sediment surface. This latter method is used to determine the more biologically relevant fraction of metal complexed onto the sediment. Water samples were collected in March and August 2000 and were analyzed for total and dissolved trace metals.Concentrations of silver, cadmium, copper, lead, mercury, and zinc in the streambed sediment of Silver Creek greatly exceeded background concentrations. These metals also exceeded established aquatic life criteria at most sites. In the Weber River, downstream of the confluence with Silver Creek, concentrations of cadmium, lead, zinc, and total mercury in streambed sediment also exceeded aquatic life guidelines, however, concentrations of metals in streambed sediment of McLeod and Kimball Creeks were lower than Silver Creek. Water-column concentrations of zinc, total mercury, and methylmercury in Silver Creek were high relative to unimpacted sites, and exceeded water quality criteria for the protection of aquatic organisms. Qualitative measurements of the macroinvertebrate community in Silver Creek were compared to the spatial distribution of metals in streambed sediment. The data indicate that impairment related to metal concentration exists in Silver Creek.

78 FR 63396 - Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to Replacement of the...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-24

... of the Elliott Bay Seawall in Seattle, Washington, for the period October 2013 to October 2018. These regulations allow for the issuance of Letters of Authorization (LOAs) for the incidental take of marine... Service, 1315 East-West Highway, Silver Spring, MD 20910- 3225. FOR FURTHER INFORMATION CONTACT: Michelle...

77 FR 27463 - Device Improvements for Pediatric X-Ray Imaging; Public Meeting; Request for Comments

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-10

... pediatric x-ray imaging that may benefit from standards development or further research. DATES: Date and... held at FDA White Oak Campus, 10903 New Hampshire Ave., Building 31 Conference Center, the Great Room..., Food and Drug Administration, 10903 New Hampshire Ave., Bldg. 66, rm. 4527, Silver Spring, MD 20993...

Electrical Conductivity Measurements of Hydroxylammonium Nitrate: Design Considerations

DTIC Science & Technology

1986-04-01

aqueous NaNO3 i• shown as well to indicate the similarity of this conductivity data with that cf HAN. The solubility of NaNO 3 in H120 is much less than... Wilmot , R-16 Commander Silver Spring, MD 20910 US Army Tank Automotive Command 1 Commander ATTN: AMSTA-TSL Naval Weapons Center Warren, MI 48397-5000

Immunogenicity of a Psoralen-Inactivated Dengue Virus Type 1 Vaccine Candidate in Mice

DTIC Science & Technology

2010-02-01

United States Naval Medical Research Center Detachment, Lima, Peru , 1 and United States Naval Medical Research Center, Silver Spring, Maryland2 R...and 28. The mice in group B mice received 10-ng vaccine doses on study clays 0, 14, and 28. The mice in group C received 10-ng vaccine doses on

78 FR 42966 - Advisory Committee for Pharmaceutical Science and Clinical Pharmacology; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-18

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2013-N-0001... advisory committee of the Food and Drug Administration (FDA). The meeting will be open to the public. Name..., Food and Drug Administration, 10903 New Hampshire Ave., Bldg. 31, rm. 2417, Silver Spring, MD 20993...

33 CFR Appendix A to Part 325 - Permit Form and Special Conditions

Code of Federal Regulations, 2010 CFR

2010-07-01

...). () Section 404 of the Clean Water Act (33 U.S.C. 1344). () Section 103 of the Marine Protection, Research and... unpermitted activities or structures caused by the activity authorized by this permit. d. Design or... Ocean Service, Office of Coast Survey, N/CS261, 1315 East West Highway, Silver Spring, Maryland 20910...

33 CFR Appendix A to Part 325 - Permit Form and Special Conditions

Code of Federal Regulations, 2011 CFR

2011-07-01

...). () Section 404 of the Clean Water Act (33 U.S.C. 1344). () Section 103 of the Marine Protection, Research and... unpermitted activities or structures caused by the activity authorized by this permit. d. Design or... Ocean Service, Office of Coast Survey, N/CS261, 1315 East West Highway, Silver Spring, Maryland 20910...

33 CFR Appendix A to Part 325 - Permit Form and Special Conditions

Code of Federal Regulations, 2013 CFR

2013-07-01

...). () Section 404 of the Clean Water Act (33 U.S.C. 1344). () Section 103 of the Marine Protection, Research and... unpermitted activities or structures caused by the activity authorized by this permit. d. Design or... Ocean Service, Office of Coast Survey, N/CS261, 1315 East West Highway, Silver Spring, Maryland 20910...

33 CFR Appendix A to Part 325 - Permit Form and Special Conditions

Code of Federal Regulations, 2012 CFR

2012-07-01

...). () Section 404 of the Clean Water Act (33 U.S.C. 1344). () Section 103 of the Marine Protection, Research and... unpermitted activities or structures caused by the activity authorized by this permit. d. Design or... Ocean Service, Office of Coast Survey, N/CS261, 1315 East West Highway, Silver Spring, Maryland 20910...

76 FR 1170 - Draft Guidance for Industry on Postmarketing Adverse Event Reporting for Medical Products and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-07

... copies of the draft guidance to the Division of Drug Information, Center for Drug Evaluation and Research..., Silver Spring, MD 20993- 0002, 301-796-8510. Regarding human drug products: Solomon Iyasu, Center for Drug Evaluation and Research, Food and Drug Administration, 10903 New Hampshire Ave., Bldg. 22, rm...

75 FR 32484 - Array-Based Cytogenetic Tests: Questions on Performance Evaluation, Result Reporting and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-08

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2010-N-0259... meeting; request for comments. SUMMARY: The Food and Drug Administration (FDA) is announcing the following.... 4321, Silver Spring, MD 20903, 301-796- 5661, e-mail: [email protected]fda.hhs.gov ; or Zivana Tezak, Food...

78 FR 59038 - Mobile Medical Applications; Guidance for Industry and Food and Drug Administration Staff...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-25

... (CDRH), Food and Drug Administration, 10903 New Hampshire Ave., Bldg. 66, Rm. 4613, Silver Spring, MD... brackets in the heading of this document. FOR FURTHER INFORMATION CONTACT: For devices regulated by CDRH... copy of the guidance may do so by using the Internet. A search capability for all CDRH guidance...

78 FR 58288 - Consistency Certification for a Proposed Project in Sterling, New York; Notice of Appeal

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-23

... and Dates: You may submit written comments concerning this appeal or requests for a public hearing to..., Room 6111, Silver Spring, MD 20910, or via email to [email protected] . Comments or requests for a public hearing must be sent in writing postmarked or emailed no later than October 23, 2013...

21 CFR 212.5 - To what drugs do the regulations in this part apply?

Code of Federal Regulations, 2011 CFR

2011-04-01

... 210 and 211 of this chapter. (b) Investigational and research PET drugs. For investigational PET drugs... this chapter, and PET drugs produced with the approval of a Radioactive Drug Research Committee in... Biosciences Library, 10903 New Hampshire Ave., Silver Spring, MD, 20993-0002, 301-796-3504, or at the National...

21 CFR 212.5 - To what drugs do the regulations in this part apply?

Code of Federal Regulations, 2014 CFR

2014-04-01

... 210 and 211 of this chapter. (b) Investigational and research PET drugs. For investigational PET drugs... this chapter, and PET drugs produced with the approval of a Radioactive Drug Research Committee in... Biosciences Library, 10903 New Hampshire Ave., Silver Spring, MD, 20993-0002, 301-796-3504, or at the National...

21 CFR 212.5 - To what drugs do the regulations in this part apply?

Code of Federal Regulations, 2012 CFR

2012-04-01

... 210 and 211 of this chapter. (b) Investigational and research PET drugs. For investigational PET drugs... this chapter, and PET drugs produced with the approval of a Radioactive Drug Research Committee in... Biosciences Library, 10903 New Hampshire Ave., Silver Spring, MD, 20993-0002, 301-796-3504, or at the National...

21 CFR 212.5 - To what drugs do the regulations in this part apply?

Code of Federal Regulations, 2013 CFR

2013-04-01

... 210 and 211 of this chapter. (b) Investigational and research PET drugs. For investigational PET drugs... this chapter, and PET drugs produced with the approval of a Radioactive Drug Research Committee in... Biosciences Library, 10903 New Hampshire Ave., Silver Spring, MD, 20993-0002, 301-796-3504, or at the National...

Cavity optomechanical spring sensing of single molecules

NASA Astrophysics Data System (ADS)

Yu, Wenyan; Jiang, Wei C.; Lin, Qiang; Lu, Tao

2016-07-01

Label-free bio-sensing is a critical functionality underlying a variety of health- and security-related applications. Micro-/nano-photonic devices are well suited for this purpose and have emerged as promising platforms in recent years. Here we propose and demonstrate an approach that utilizes the optical spring effect in a high-Q coherent optomechanical oscillator to dramatically enhance the sensing resolution by orders of magnitude compared with conventional approaches, allowing us to detect single bovine serum albumin proteins with a molecular weight of 66 kDa at a signal-to-noise ratio of 16.8. The unique optical spring sensing approach opens up a distinctive avenue that not only enables biomolecule sensing and recognition at individual level, but is also of great promise for broad physical sensing applications that rely on sensitive detection of optical cavity resonance shift to probe external physical parameters.

Temporal analyses of Salmonellae in a headwater spring ecosystem reveals the effects of precipitation and runoff events.

PubMed

Gaertner, James P; Garres, Tiffany; Becker, Jesse C; Jimenez, Maria L; Forstner, Michael R J; Hahn, Dittmar

2009-03-01

Sediments and water from the spring and slough arm of Spring Lake, the pristine headwaters of the San Marcos River, Texas, were analyzed for Salmonellae by culture and molecular techniques before and after three major precipitation events, each with intermediate dry periods. Polymerase chain reaction (PCR)-assisted analyses of enrichment cultures detected Salmonellae in samples after all three precipitation events, but failed to detect them immediately prior to the rainfall events. Detection among individual locations differed with respect to the precipitation event analyzed, and strains isolated were highly variable with respect to serovars. These results demonstrate that rainwater associated effects, most likely surface runoff, provide an avenue for short-term pollution of aquatic systems with Salmonellae that do not, however, appear to establish for the long-term in water nor sediments.

Stennis personnel participate in test program

NASA Technical Reports Server (NTRS)

2008-01-01

Fernando Figueroa (left), an aerospace technologist at Stennis, and John Schmatzel (center), a professor on loan from Rowan University in Glassboro, N.J., joined Ray Wang, president of Mobitrum Corp., in Silver Springs, Md., to test a virtual sensor instrument in development. The test was performed as part of NASA's Facilitated Access to the Space Environment for Technology Development and Training program.

Career Immersion. School-to-Work Outreach Project 1997 Exemplary Model/Practice/Strategy.

ERIC Educational Resources Information Center

Minnesota Univ., Minneapolis. Inst. on Community Integration.

The Career Immersion program, which has been conducted since 1989-90 at Silver Spring Elementary School in Milwaukee, Wisconsin, introduces the world of work to students at an early age. The program's primary activities involve hands-on, school-based learning in which all students participate. Students between the ages of 3 and 13 participate in 2…

Determination of Acoustic Effects on Marine Mammals and Sea Turtles for the Atlantic Fleet Training and Testing Environmental Impact Statement/Overseas Environmental Impact Statement

DTIC Science & Technology

2012-03-12

column than sounds with lower frequencies ( Urick , 1983). Additionally, these systems are generally operated in the vicinity of the sea floor, thus...Water,” TR-76-116, Naval Surface Weapons Center, White Oak, Silver Springs, MD. Urick , R. J. (1983), Principles of Underwater Sound, McGraw-Hill

Metric Selection for Ecosystem Restoration

DTIC Science & Technology

2013-06-01

focus on wetlands, submerged aquatic vegetation, oyster reefs, riparian forest, and wet prairie (Miner 2005). The objective of these Corps...of coastal habitats, Volume Two: Tools for monitoring coastal habitats. NOAA Coastal Ocean Program Decision Analysis Series No. 23. Silver Spring, MD...NOAA National Centers for Coastal Ocean Science. Thom, R. M., and K. F. Wellman. 1996. Planning aquatic ecosystem restoration monitoring programs

75 FR 30769 - Endangered and Threatened Species; Proposed Listing of Nine Distinct Population Segments of...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-02

... Highway, Room 13657, Silver Spring, MD 20910 or USFWS National Sea Turtle Coordinator, U.S. Fish and..., fax 301-713-0376, e-mail [email protected] ), or Emily Bizwell, USFWS (ph. 404-679-7149, fax 404- 679-7081, e-mail emily[email protected] ). Persons who use a Telecommunications device for the deaf...

75 FR 23242 - International Whaling Commission; 62nd Annual Meeting; Announcement of Public Meetings

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-03

... be held in the NOAA Science Center Room, 1301 East-West Highway, Silver Spring, MD 20910. FOR FURTHER... posted on the IWC Secretariat's website at http://www.iwcoffice.org . NOAA will hold meetings prior to...., Seattle, WA 98115. The May 26 meeting will be held in the NOAA Science Center Room, 1301 East-West Highway...

Stennis personnel participate in test program

NASA Image and Video Library

2008-09-09

Fernando Figueroa (left), an aerospace technologist at Stennis, and John Schmatzel (center), a professor on loan from Rowan University in Glassboro, N.J., joined Ray Wang, president of Mobitrum Corp., in Silver Springs, Md., to test a virtual sensor instrument in development. The test was performed as part of NASA's Facilitated Access to the Space Environment for Technology Development and Training program.

Copy image of "'Under the Great Arch' of Refectory Bridge ...

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

Copy image of "'Under the Great Arch' of Refectory Bridge connecting the Dining Room with the Practice House, Delta, and the Villa. The Refectory Cloister is seen beyond the arch"; a similar, but recent, view can be seen in MD-1109-A-16. (NPS view book, p. 25) - National Park Seminary, Main, Linden Lane, Silver Spring, Montgomery County, MD

Twenty-First Asilomar Conference on Polymeric Materials

DTIC Science & Technology

1998-03-10

Silver Spring, MD a ’Micro- and Nano- Layered Polymer Composites" Professor Eric Baer Case Western Reserve University Cleveland, OH "Theoretical...Corporation Roswell, GA 30076 Dr. Zhong-he Shen Nalge Nunc International Naperville, IL 60563 Dr. Mark Sinsky Goodyear Tire & Rubber Company...on Polymers February 22-25, 1998 Micro-arid Nano- Layered Polymer Composites Eric Baer Department of Macromolecular Science Case Western

Species- and size-specific variability of mercury concentrations in four commercially important finfish and their prey from the northwest Atlantic.

PubMed

Staudinger, Michelle D

2011-04-01

Total mercury was analyzed as a function of body length, season, and diet in four commercially and recreationally important marine fish, bluefish (Pomatomus saltatrix), goosefish (Lophius americanus), silver hake (Merluccius bilinearis), and summer flounder (Paralichthys dentatus), collected from continental shelf waters of the northwest Atlantic Ocean. Mercury levels in the dorsal muscle tissue of 115 individuals ranged from 0.006 to 1.217 μg/g (wet weight) and varied significantly among species. The relationship between predator length and mercury concentration was linear for bluefish and summer flounder, while mercury levels increased with size at an exponential rate for silver hake and goosefish. Mercury burdens were the highest overall in bluefish, but increased with size at the greatest rate in silver hake. Seasonal differences were detected for bluefish and goosefish with mercury levels peaking during summer and spring, respectively. Prey mercury burdens and predator foraging habits are discussed as the primary factors influencing mercury accumulation. Copyright © 2011 Elsevier Ltd. All rights reserved.

Ink-jet printing technology enables self-aligned mould patterning for electroplating in a single step

NASA Astrophysics Data System (ADS)

Meissner, M. V.; Spengler, N.; Mager, D.; Wang, N.; Kiss, S. Z.; Höfflin, J.; While, P. T.; Korvink, J. G.

2015-06-01

We present a new self-aligned, mask-free micro-fabrication method with which to form thick-layered conductive metal micro-structures inside electroplating moulds. Seed layer patterning for electroplating was performed by ink-jet printing using a silver nano-particle ink deposited on SU-8 or Ordyl SY permanent resist. The silver ink contact angle on SU-8 was adjusted by oxygen plasma followed by a hard bake. Besides functioning as a seed layer, the printed structures further served as a shadow mask during patterning of electroplating moulds into negative photoresist. The printed silver tracks remained in strong adhesion to the substrate when exposed to the acidic chemistry of the electroplating bath. To demonstrate the process, we manufactured rectangular, low-resistivity planar micro-coils for use in magnetic resonance microscopy. MRI images of a spring onion with an in-plane resolution down to 10 µm × 10 µm were acquired using a micro-coil on an 11.7 T MRI scanner.

Geological-hydrogeochemical characteristics of a “silver spring” water source (the Lozovy ridge)

NASA Astrophysics Data System (ADS)

Ivanova, I. S.; Bragin, I. V.; Chelnokov, G. A.; Bushkareva, K. Yu; Shvagrukova, E. V.

2016-03-01

Geological and hydrogeological characteristics of the Lozovy ridge (Southern Primorye) are studied, as far as karst phenomena are widely distributed within its boundaries. Water-bearing rocks of the karst water source “Silver Spring” (“Serebryany Klyuch”), which is located near the bottom of the “Bear’s fang” (“Medvezhiy klyk”) cave, are investigated. It is found that karst rocks are presented by calcite (CaCO3), and an accessory mineral is barite (BaSO4). It is determined that among the trace elements forming the composition of carbonate water-bearing rocks the maximum concentrations are typical for Sr, Ba, Fe, Al, Za, Mn, Cu, and Ni. Also, the chemical composition of the waters taken from the “Silver Spring” water source is studied. These waters are fresh, hydrocarbonate, calcium, and weakly alkaline. Among the elements of the spring, such elements as Sr, Ba, Fe, Al, Zn, Mn, Cu, and Ni have the maximum concentration. The other elements have concentrations less than 1 µg/l.

Silver Peak Innovative Exploration Project (Ram Power Inc.)

DOE Data Explorer

Miller, Clay

2010-01-01

Data generated from the Silver Peak Innovative Exploration Project, in Esmeralda County, Nevada, encompasses a “deep-circulation (amagmatic)” meteoric-geothermal system circulating beneath basin-fill sediments locally blanketed with travertine in western Clayton Valley (lithium-rich brines from which have been mined for several decades). Spring- and shallow-borehole thermal-water geochemistry and geothermometry suggest that a Silver Peak geothermal reservoir is very likely to attain the temperature range 260- 300oF (~125-150oC), and may reach 300-340oF (~150-170oC) or higher (GeothermEx, Inc., 2006). Results of detailed geologic mapping, structural analysis, and conceptual modeling of the prospect (1) support the GeothermEx (op. cit.) assertion that the Silver Peak prospect has good potential for geothermal-power production; and (2) provide a theoretical geologic framework for further exploration and development of the resource. The Silver Peak prospect is situated in the transtensional (regional shearing coupled with extension) Walker Lane structural belt, and squarely within the late Miocene to Pliocene (11 Ma to ~5 Ma) Silver Peak-Lone Mountain metamorphic core complex (SPCC), a feature that accommodated initial displacement transfer between major right-lateral strike- slip fault zones on opposite sides of the Walker Lane. The SPCC consists essentially of a ductiley-deformed lower plate, or “core,” of Proterozoic metamorphic tectonites and tectonized Mesozoic granitoids separated by a regionally extensive, low-angle detachment fault from an upper plate of severely stretched and fractured structural slices of brittle, Proterozoic to Miocene-age lithologies. From a geothermal perspective, the detachment fault itself and some of the upper-plate structural sheets could function as important, if secondary, subhorizontal thermal-fluid aquifers in a Silver Peak hydrothermal system.

An ultrastable conjugate of silver nanoparticles and protein formed through weak interactions

NASA Astrophysics Data System (ADS)

Brahmkhatri, Varsha P.; Chandra, Kousik; Dubey, Abhinav; Atreya, Hanudatta S.

2015-07-01

In recent years, silver nanoparticles (AgNPs) have attracted significant attention owing to their unique physicochemical, optical, conductive and antimicrobial properties. One of the properties of AgNPs which is crucial for all applications is their stability. In the present study we unravel a mechanism through which silver nanoparticles are rendered ultrastable in an aqueous solution in complex with the protein ubiquitin (Ubq). This involves a dynamic and reversible association and dissociation of ubiquitin from the surface of AgNP. The exchange occurs at a rate much greater than 25 s-1 implying a residence time of <40 ms for the protein. The AgNP-Ubq complex remains stable for months due to steric stabilization over a wide pH range compared to unconjugated AgNPs. NMR studies reveal that the protein molecules bind reversibly to AgNP with an approximate dissociation constant of 55 μM and undergo fast exchange. At pH > 4 the positively charged surface of the protein comes in contact with the citrate capped AgNP surface. Further, NMR relaxation-based experiments suggest that in addition to the dynamic exchange, a conformational rearrangement of the protein takes place upon binding to AgNP. The ultrastability of the AgNP-Ubq complex was found to be useful for its anti-microbial activity, which allowed the recycling of this complex multiple times without the loss of stability. Altogether, the study provides new insights into the mechanism of protein-silver nanoparticle interactions and opens up new avenues for its application in a wide range of systems.In recent years, silver nanoparticles (AgNPs) have attracted significant attention owing to their unique physicochemical, optical, conductive and antimicrobial properties. One of the properties of AgNPs which is crucial for all applications is their stability. In the present study we unravel a mechanism through which silver nanoparticles are rendered ultrastable in an aqueous solution in complex with the protein ubiquitin (Ubq). This involves a dynamic and reversible association and dissociation of ubiquitin from the surface of AgNP. The exchange occurs at a rate much greater than 25 s-1 implying a residence time of <40 ms for the protein. The AgNP-Ubq complex remains stable for months due to steric stabilization over a wide pH range compared to unconjugated AgNPs. NMR studies reveal that the protein molecules bind reversibly to AgNP with an approximate dissociation constant of 55 μM and undergo fast exchange. At pH > 4 the positively charged surface of the protein comes in contact with the citrate capped AgNP surface. Further, NMR relaxation-based experiments suggest that in addition to the dynamic exchange, a conformational rearrangement of the protein takes place upon binding to AgNP. The ultrastability of the AgNP-Ubq complex was found to be useful for its anti-microbial activity, which allowed the recycling of this complex multiple times without the loss of stability. Altogether, the study provides new insights into the mechanism of protein-silver nanoparticle interactions and opens up new avenues for its application in a wide range of systems. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr03047a

Silver metal nano-matrixes as high efficiency and versatile catalytic reactors for environmental remediation

NASA Astrophysics Data System (ADS)

Dumée, Ludovic F.; Yi, Zhifeng; Tardy, Blaise; Merenda, Andrea; Des Ligneris, Elise; Dagastine, Ray R.; Kong, Lingxue

2017-03-01

Nano-porous metallic matrixes (NMMs) offer superior surface to volume ratios as well as enhanced optical, photonic, and electronic properties to bulk metallic materials. Such behaviours are correlated to the nano-scale inter-grain metal domains that favour the presence of electronic vacancies. In this work, continuous 3D NMMs were synthesized for the first time through a simple diffusion-reduction process whereby the aerogel matrix was functionalized with (3-Mercaptopropyl)trimethoxysilane. The surface energy of the silica monolith templates was tuned to improve the homogeneity of the reduction process while thiol functionalization facilitated the formation of a high density of seeding points for metal ions to reduce. The diameter of NMMs was between 2 and 1000 nm, corresponding to a silver loading between 1.23 and 41.16 at.%. A rates of catalytic degradation kinetics of these NMMS which is three orders of magnitude higher than those of the non-functionalized silver-silica structures. Furthermore, the enhancement in mechanical stability at nanoscale which was evaluated by Atomic Force Microscopy force measurements, electronic density and chemical inertness was assessed and critically correlated to their catalytic potential. This strategy opens up new avenues for design of complex architectures of either single or multi-metal alloy NMMs with enhanced surface properties for various applications.

Silver metal nano-matrixes as high efficiency and versatile catalytic reactors for environmental remediation

PubMed Central

Dumée, Ludovic F.; Yi, Zhifeng; Tardy, Blaise; Merenda, Andrea; des Ligneris, Elise; Dagastine, Ray R.; Kong, Lingxue

2017-01-01

Nano-porous metallic matrixes (NMMs) offer superior surface to volume ratios as well as enhanced optical, photonic, and electronic properties to bulk metallic materials. Such behaviours are correlated to the nano-scale inter-grain metal domains that favour the presence of electronic vacancies. In this work, continuous 3D NMMs were synthesized for the first time through a simple diffusion-reduction process whereby the aerogel matrix was functionalized with (3-Mercaptopropyl)trimethoxysilane. The surface energy of the silica monolith templates was tuned to improve the homogeneity of the reduction process while thiol functionalization facilitated the formation of a high density of seeding points for metal ions to reduce. The diameter of NMMs was between 2 and 1000 nm, corresponding to a silver loading between 1.23 and 41.16 at.%. A rates of catalytic degradation kinetics of these NMMS which is three orders of magnitude higher than those of the non-functionalized silver-silica structures. Furthermore, the enhancement in mechanical stability at nanoscale which was evaluated by Atomic Force Microscopy force measurements, electronic density and chemical inertness was assessed and critically correlated to their catalytic potential. This strategy opens up new avenues for design of complex architectures of either single or multi-metal alloy NMMs with enhanced surface properties for various applications. PMID:28332602

Water and Bottom Properties of a Coastal Environment Derived from Hyperion Data Measured from the EO-1 Spacecraft Platform

DTIC Science & Technology

2007-12-26

areas have suffered shoreline erosions, declines in aquatic species, losses in seagrass beds, and bleaching of coral reefs [e.g., 20080211243 C,2007...L. Miller and M. P. Crosby, "The extent and condition of US Coral Reefs," NOAA’s State of the Coast Report, Silver Spring, MD (1998). [2] M. 0. Hall

Hearing and Underwater Noise Exposure

DTIC Science & Technology

1985-08-27

Ordnance Laboratory, White Oak, Silver Springs, Md. Corso, J. F. (1963) Bone-conduction thresholds for sonic and ultrasonic frequencies. J. Acoust...Soc. Am. 35, 1738-1743. Corso, J. F., & Levine, M. (1965a) Sonic and Ultrasonic equal loudness contours. J. Exp. Psychol. 70, 412-416. Corso, J...KEY WORDS (Continue on reverse aide II neceaaary and identity by block number) Hearing, Deafness, Sonar, Noise, Sound, Ultrasound, Infra -sound

Medical Surveillance Monthly Report. Volume 20, Number 11

DTIC Science & Technology

2013-11-01

5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Medical Surveillance Monthly Report (MSMR),Armed Forces...Health Surveillance Center,11800 Tech Road, Suite 220 (MCAF-CS),Silver Spring,MD,20904 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING... performed to determine the circumstances surrounding the event, the week of train- ing (WOT) in which it occurred, comor- bid conditions diagnosed

Role of African American Churches in Cancer Prevention Services

DTIC Science & Technology

1999-08-01

first meeting of the Steering Committee a) Denomination selection occurred for three denominations: Seventh Day Adventist (SDA), Presbyterian, and...ksydnor@jhsph.edu Dr. DeWitt Williams Health and Temperance Director World Headquarters of Seventh - Day Adventist 12501 Old Columbia Pike Silver Spring...Fellows Program in HPM and also as a member of the Seventh - Day Adventist Church (SDA). Dr. Glassman develops consumer-oriented, tailored health messages

The saltiest springs in the Sierra Nevada, California

USGS Publications Warehouse

Moore, James G.; Diggles, Michael F.; Evans, William C.; Klemic, Karin

2017-07-20

The five saltiest springs in the Sierra Nevada in California are found between 38.5° and 38.8° N. latitude, on the South Fork American River; on Caples Creek, a tributary of the Silver Fork American River; and on the North Fork Mokelumne River. The springs issue from Cretaceous granitic rocks in the bottoms of these major canyons, between 1,200- and 2,200-m elevation. All of these springs were well known to Native Americans, who excavated meter-sized basins in the granitic rock, within which they produced salt by evaporation near at least four of the five spring sites. The spring waters are dominated by Cl, Na, and Ca; are enriched relative to seawater in Ca, Li, and As; and are depleted in SO4, Mg, and K. Tritium analyses indicate that the spring waters have had little interaction with rainfall since about 1954. The waters are apparently an old groundwater of meteoric origin that resided at depth before moving up along fractures to the surface of the exhumed granitic rocks. However, along the way these waters incorporated salts from depth, the origin of which could have been either from marine sedimentary rocks intruded by the granitic magmas or from fluid inclusions in the granitic rocks. Prolonged storage at depth fostered water-rock interactions that undoubtedly modified the fluid compositions.

An Empirical Model of the Vertical Structure of German Fogs.

DTIC Science & Technology

1980-11-01

Fitz ) ATTN: Dr. John E. Cockayne Washington, DC 20305 McLean, VA 22102 Director US Army Nuclear & Chemical Agency Defense Nuclear Agency ATTN: MONA-WE...Information Center John M. Hobbie ATTN: DRSMI-RPRD (Documents Section) c/o Kentron International Redstone Arsenal, AL 35809 2003 Byrd Spring Road...ATTN: Mr. John D. Carlyle Culter City, CA 90230 5383 Hollister Avenue Santa Barbara, CA 93111 Commander US Army Combat Developments Commander

State of STEM (SoSTEM) Address

NASA Image and Video Library

2014-01-29

Montgomery Blair High School Student Newspaper “Silver Chips” Online Editor-in-Chief Aanchal Johri, right, and Photo Editor Emma Howells, left, from Silver Spring, MD. interview Joey Hudy, Anthem, AZ, 16-year-old self-described “Maker” at the annual White House State of Science, Technology, Engineering, and Math (SoSTEM) address, Wednesday, Jan. 29, 2014, in the South Court Auditorium in the Eisenhower Executive Office Building on the White House complex in Washington. Joey sat with the First Lady at the President’s 2014 State of the Union Address after his first shot to fame in 2012 when he attended the White House Science Fair where the President took a turn using his “extreme marshmallow cannon” to launch a marshmallow across the East Room of the White House. Photo Credit: (NASA/Bill Ingalls)

Proceedings of the TRADOC/Training Developments Institute Fifth Chiefs of Analysis Seminar.

DTIC Science & Technology

1981-09-30

exposed to behaviorally specific examples of discrete points+ on a scale ( Lawton & Borman, 1978). Sel f-Assessment Trainees receive operant test...peer assessment. Psychologi- cal Bulletin, 1979., Lawton , G. W., & Borman, W. C. Constructing stimuli with known true scores for determining validity...AR Jamie B. Telegadis, West Hempstead, Rick D. Archer, Boulder, CO " . Patricia Kirkham. Cumming. GA NY - i W, - Michael F. Audet. Silver Spring. MD

U.S. Army Medical Department Journal, July-September 2006

DTIC Science & Technology

2006-09-01

Center from Operation Enduring Freedom and Operation Iraqi Freedom. back pain, etc. Although statistics are currently and exposure to depleted uranium . By...Washington, DC. LTC Niebuhr is oil the staff of the Division of Preventive Medicine, Walter Reed Army Institute of Research, Silver Spring, Maryland...is "primarily concerned populations was found; leading Barber to interpret the with the valuable differences in people that result from findings, as

Acute Blast Injury Reduces Brain Abeta in Two Rodent Species

DTIC Science & Technology

2012-12-01

NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Naval Medical...Research Center,Operational and Undersea Medicine Directorate,Department of Neurotrauma,Silver Spring,MD, 20910 8. PERFORMING ORGANIZATION REPORT NUMBER 9...monoclonal antibody that recognizes phosphorylated epitopes on the mouse mid-sized and heavy neurofilament proteins (1:500; Covance , Denver, PA, USA

Medical Surveillance Monthly Report. Volume 21, Number 3

DTIC Science & Technology

2014-03-01

PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Medical Surveillance Monthly Report (MSMR),Armed Forces Health Surveillance Center,11800 Tech Road, Suite 220...MCAF-CS),Silver Spring,MD,20904 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR...travel, use of air con- ditioning, and other recreational activities that increase risk of exposure to Legionella bacteria (e.g., use of hot tubs

Plenary Speech, Keynote Speeches, List of Attendees of Symposium on the Interaction of Non-Nuclear Munitions with Structures (2nd), Held at Panama City Beach, Florida on April 15-18, 1985

DTIC Science & Technology

1985-04-01

5urfacC ’.1eapons Certer Albert Heerman Cude RI5 Uetherlands Army Silver Spring, Maryland 20910 Mauritskade 53, The Rague THE NETHERLANDS , Dieter...North Carolina 27609 University of Boulder Camu )s Box 428 Lawrence G. Ullyatt - Boulder, Cnloradc 80309 Denver Research Institute University of Denver

Linear Chebyshev Complex Function Approximation.

DTIC Science & Technology

1981-02-26

CONTINUE C C C LEVEL I C C LEVaI KwC 30 KUKeI C C THE NEXT VARIABLE IS NOT USED, BUT IS IN THE PUBLISHED CODE. KPIuKi1 C NPI MK=NP 1-K MODE2 0 DO 40 J=K,M...WEAPONS CENTER, Silver Spring, Code 432-4 (Egbert H. Jackson)I DWTNSRDC ANNAI DWTNSRDC CARDI NRL, Code 5330 (Dr. Robert J. Adams ), 5209 (Russell M. Brown

View looking southeast to causeway running from the Senior House ...

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

View looking southeast to causeway running from the Senior House Annex to Ament Hall (ballroom) including two octagon-shaped pavilions located between Ament Hall and the Music Hall and including the causeway extension leading to the Swiss Chalet; note Japanese Pagoda in the background. View likely taken from the Dog Bridge. - National Park Seminary, Chateau Causeways, Between Linden Lane & Beach Drive, Silver Spring, Montgomery County, MD

Development, Implementation, and Skill Assessment of the NOAA/NOS Great Lakes Operational Forecast System

DTIC Science & Technology

2011-01-01

USA) 2011 Abstract The NOAA Great Lakes Operational Forecast System ( GLOFS ) uses near-real-time atmospheric observa- tions and numerical weather...Operational Oceanographic Products and Services (CO-OPS) in Silver Spring, MD. GLOFS has been making operational nowcasts and forecasts at CO-OPS... GLOFS ) uses near-real-time atmospheric observations and numerical weather prediction forecast guidance to produce three-dimensional forecasts of water

Simple and strong: twisted silver painted nylon artificial muscle actuated by Joule heating

NASA Astrophysics Data System (ADS)

Mirvakili, Seyed M.; Rafie Ravandi, Ali; Hunter, Ian W.; Haines, Carter S.; Li, Na; Foroughi, Javad; Naficy, Sina; Spinks, Geoffrey M.; Baughman, Ray H.; Madden, John D. W.

2014-03-01

Highly oriented nylon and polyethylene fibres shrink in length when heated and expand in diameter. By twisting and then coiling monofilaments of these materials to form helical springs, the anisotropic thermal expansion has recently been shown to enable tensile actuation of up to 49% upon heating. Joule heating, by passing a current through a conductive coating on the surface of the filament, is a convenient method of controlling actuation. In previously reported work this has been done using highly flexible carbon nanotube sheets or commercially available silver coated fibres. In this work silver paint is used as the Joule heating element at the surface of the muscle. Up to 29% linear actuation is observed with energy and power densities reaching 840 kJ m-3 (528 J kg-1) and 1.1 kW kg-1 (operating at 0.1 Hz, 4% strain, 1.4 kg load). This simple coating method is readily accessible and can be applied to any polymer filament. Effective use of this technique relies on uniform coating to avoid temperature gradients.

Effect of cysteine and humic acids on bioavailability of Ag from Ag nanoparticles to a freshwater snail

USGS Publications Warehouse

Luoma, Samuel N.; Tasha Stoiber,; Croteau, Marie-Noele; Isabelle Romer,; Ruth Merrifeild,; Lead, Jamie

2016-01-01

Metal-based engineered nanoparticles (NPs) will undergo transformations that will affect their bioavailability, toxicity and ecological risk when released to the environment, including interactions with dissolved organic material. The purpose of this paper is to determine how interactions with two different types of organic material affect the bioavailability of silver nanoparticles (AgNPs). Silver uptake rates by the pond snail Lymnaea stagnalis were determined after exposure to 25 nmol l-1 of Ag as PVP AgNPs, PEG AgNPs or AgNO3, in the presence of either Suwannee River humic acid or cysteine, a high-affinity thiol-rich organic ligand. Total uptake rate of Ag from the two NPs was either increased or not strongly affected in the presence of 1 – 10 mg 1-1 humic acid. Humic substances contain relatively few strong ligands for Ag explaining their limited effects on Ag uptake rate. In contrast, Ag uptake rate was substantially reduced by cysteine. Three components of uptake from the AgNPs were quantified in the presence of cysteine using a biodynamic modeling approach: uptake of dissolved Ag released by the AgNPs, uptake of a polymer or large (>3kD) Ag-cysteine complex and uptake of the nanoparticle itself. Addition of 1:1 Ag:cysteine reduced concentrations of dissolved Ag, which contributed to, but did not fully explain the reductions in uptake. A bioavailable Ag-cysteine complex (> 3kD) appeared to be the dominant avenue of uptake from both PVP AgNPs and PEG AgNPs in the presence of cysteine. Quantifying the different avenues of uptake sets the stage for studies to assess toxicity unique to NPs.

A bill to designate the facility of the United States Postal Service located at 14 Red River Avenue North in Cold Spring, Minnesota, as the "Officer Tommy Decker Memorial Post Office".

THOMAS, 113th Congress

Sen. Klobuchar, Amy [D-MN

2014-06-18

Senate - 06/18/2014 Read twice and referred to the Committee on Homeland Security and Governmental Affairs. (All Actions) Notes: For further action, see H.R.43, which became Public Law 113-204 on 12/16/2014. Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Proceedings of the Complex Systems Engineering Synthesis and Assessment Technology Workshop Held in Silver Spring, Maryland on 20-24 July 1992

DTIC Science & Technology

1992-07-24

Pmo Pbuf Tarr PenvTmm Patneo TTneo Teo Pateo ’,- r 0,Traneo 8 a e P naco Pfa Te aco Tsro- - PPatnen Them, Teyn Pate.. ••==P a• Tat e,- Fr ti I 3 456...Trivedi. Reliability modeling using SHARPE. IEEE Trans. Reliability, R-36(2):186-193, June 1987. 3 [14] K. Salem and H. Garcia-Molina. Disk striping

Automated Microwave Dielectric Constant Measurement

DTIC Science & Technology

1987-03-01

IJSWC TR 86-46 AD.-A 184 182 AUTOMATED MICROWAVE DIELECTRIC CONSTANT MEASUREMENT SYTIEM BY B. C. GLANCY A. KRALL PESEARCH AND TECHNOLOGY DEPARTMENT...NO0. NO. ACCESSION NO. Silver Spring, Maryland 20903-500061152N ZROO1 ZRO131 R1AA29 11. TITLE (Include Security Classification) AUTOMATED MICROWAVE ...constants as a funct on of microwave frequency has been simplified using an automated testing apparatus. This automated procedure is based on the use of a

Field Evaluations of Topical Arthropod Repellents in North, Central, and South America

DTIC Science & Technology

2014-09-01

of Research , Entomology Branch, Silver Spring, MD. 2 Present address: U.S. Army Medical Materiel Development Ac- tivity, Pharmaceutical Systems...fever andmalaria (De La Rocque et al. 2011). As a result, concern over arthropod-borne diseaseswaned, andmanywere clas- siÞed as “ tropical diseases...scientiÞc evaluations of other topical repellents (WHO 2009, EPA 2010). It is Thismaterial has been reviewedby theWalterReedArmy Institute of Research

National Consultation on Safety and Force: An Opportunity for Police-Minority Community Cooperation (Silver Spring, Maryland, December 11-13, 1979). Summary Report.

ERIC Educational Resources Information Center

Department of Justice, Washington, DC. Community Relations Service.

This report presents the proceedings of a conference held to examine the relationship between the police and minority groups with a focus on the problem of police use of excessive force. Successful community-police efforts to increase safety and reduce the use of force are described in case studies from four cities. Also presented are the texts of…

Naval Medical R and D News. Volume 8, Issue 12, December 2016

DTIC Science & Technology

2016-12-01

Together to Fight Dengue Virus NMRC Researcher Shares Results from Traveler’s Diarrhea Study SILVER SPRING, Md- The American Society of Tropical...Research teamed up in a study to develop an assay to better characterize how the immune system responds to dengue virus infections. The results of this...collaboration for this study came about through common interests. The Navy and Army deploy service members to areas where dengue fever is prevalent

Medical Surveillance Monthly Report (MSMR). Volume 19, Number 11, November 2012

DTIC Science & Technology

2012-11-01

REPORT TYPE 3. DATES COVERED 00-00-2012 to 00-00-2012 4. TITLE AND SUBTITLE Medical Surveillance Monthly Report 5a. CONTRACT NUMBER 5b. GRANT...ADDRESS(ES) Medical Surveillance Monthly Report (MSMR),Armed Forces Health Surveillance Center,11800 Tech Road, Suite 220 (MCAF-CS),Silver Spring,MD...most apparent medical eff ects of the war – musculoskeletal and internal organ injuries, traumatic brain injuries, vision and hear- ing decrements

Preclinical Evaluation of the Effects of Aeromedical Evacuation on Military-Relevant Casualties

DTIC Science & Technology

2017-10-01

PRINCIPAL INVESTIGATOR: Dr. Richard McCarron RECIPIENT: Naval Medical Research Center Silver Spring, MD 20910 REPORT DATE: October 2017 TYPE OF REPORT ...public release; distribution is unlimited. The views, opinions and/or findings contained in this report are those of the author(s) and should not be...construed as an official Department of the Army position, policy or decision unless so designated by other documentation. REPORT DOCUMENTATION PAGE

Developing a Model for Predicting Snowpack Parameters Affecting Vehicle Mobility,

DTIC Science & Technology

1983-05-01

Service River Forecast System -Snow accumulation and JO ablation model. NOAA Technical Memorandum NWS HYDRO-17, National Weather Service, JS Silver Spring... Forecast System . This model indexes each phys- ical process that occurs in the snowpack to the air temperature. Although this results in a signifi...pressure P Probability Q Energy Q Specific humidity R Precipitation s Snowfall depth T Air temperature t Time U Wind speed V Water vapor

40. Photocopy of photograph (original negative is property of the ...

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

40. Photocopy of photograph (original negative is property of the Central Connecticut Regional Water Authority and preserved in their archives at 90 Sargent Drive, New Haven, Connecticut 06511-5966), photographer unknown, dated in the spring of 1903. View of the start of construction of the slow sand filter. In the fall of 1902 the filter plant area was graded and flooded with water. This helped to create a hard and impervious watertight base when drained. During the spring of 1903, the water WS drained off and the whole area rolled with a grooved roller. The photograph shows the horse drawn grooved grading rollers starting to prepare the filter base. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

One-step fabrication of multifunctional composite polyurethane spider-web-like nanofibrous membrane for water purification.

PubMed

Pant, Hem Raj; Kim, Han Joo; Joshi, Mahesh Kumar; Pant, Bishweshwar; Park, Chan Hee; Kim, Jeong In; Hui, K S; Kim, Cheol Sang

2014-01-15

A stable silver-doped fly ash/polyurathene (Ag-FA/PU) nanocomposite multifunctional membrane is prepared by a facile one-step electrospinning process using fly ash particles (FAPs). Colloidal solution of PU with FAPs and Ag metal precursor was subjected to fabricate nanocomposite spider-web-like membrane using electrospinning process. Presence of N,N-dimethylformamide (solvent of PU) led to reduce silver nitrate into Ag NPs. Incorporation of Ag NPs and FAPs through electrospun PU fibers is proven through electron microscopy and spectroscopic techniques. Presence of these NPs on PU nanofibers introduces several potential physicochemical properties such as spider-web-like nano-neeting for NPs separation, enhanced absorption capacity to remove carcinogenic arsenic (As) and toxic organic dyes, and antibacterial properties with reduce bio-fouling for membrane filter application. Preliminary observations used for above-mentioned applications for water treatment showed that it will be an economically and environmentally friendly nonwoven matrix for water purification. This simple approach highlights new avenues about the utilization of one pollutant material to control other pollutants in scalable and inexpensive ways. Copyright © 2013 Elsevier B.V. All rights reserved.

Lake Superior lipids

EPA Pesticide Factsheets

Fish chemistry data (d13C, d15N, C:N, lipid content) published in Rapid Commun. Mass Spectrom. 2015, 29, 2069??2077 DOI: 10.1002/rcm.7367This dataset is associated with the following publication:Hoffman , J., M. Sierszen , and A. Cotter. Fish tissue lipid-C:N relationships for correcting ä13C values and estimating lipid content in aquatic food web studies. Rapid Communications in Mass Spectrometry. Wiley InterScience, Silver Spring, MD, USA, 29(21): 2069–2077, (2015).

Serum Penicillin G Levels Are Lower Than Expected in Adults within Two Weeks of Administration of 1.2 Million Units

DTIC Science & Technology

2011-10-01

United States of America, 3 United States Department of Defense Global Emerging Infections Surveillance and Response System, Silver Spring, Maryland... infections . Citation: Broderick MP, Hansen CJ, Russell KL, Kaplan EL, Blumer JL, et al. (2011) Serum Penicillin G Levels Are Lower Than Expected in...Defense Global Emerging Infections Surveillance and Response System, a Division of the Armed Forces Health Surveillance Center, WU# 60501, http://afhsc.mil

CHIMAERA System for Cloud Retrievals v 6.0.85

NASA Technical Reports Server (NTRS)

Wind, Galina; Platnick, Steven; Meyer, Kerry; Amarasinghe, Nandana; Marchant, Benjamin; Arnold, Tom; King, Michael D.

2015-01-01

Organizers of the MODIS-VIIRS Science Team Meeting, held May 18-22, 2015 in Silver Spring, MD plan to post the presentations and posters to the NASA MODIS website: http:modis.gsfc.nasa.govsci_teammeetings201505index.php. The MODIS Science Team Meeting is held twice a year, so that the members of the science team may assemble and discuss data they have collected, ideas they have formed, and future issues that apply to the MODIS Mission.

Electrochemistry and Spectroelectrochemistry of Polynuclear Zinc Phthalocyanines: Formation of Mixed Valence Cation Radical Species.

DTIC Science & Technology

1988-02-25

No. No. Copies Cpe Office of Naval Research 2 Dr. David You.)g Attn: Code 1113 Code 334 800 N. Quinc’ Street NORDA Arlington, Virginia 22217-5000 NSTL...Naval Surface Weapons Center Chapel Hill, North Carolina 27514 Silver Spring, Maryland 20910 Or. R. A. Marcus Dr. Michael J. Weaver Department of...Microprocessor model 340 spectrometer. Cyclic and dif, rential pulse voltammetry were performed with a Princeton Applied Research (PARC) model 174A

Biomimetic Sniffing with an Artificial Dogs Nose Leads to Improvements in VaporSampling and Detection

DTIC Science & Technology

2016-07-25

and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD Abstract Unlike current chemical trace detection technology, dogs...mm vertically from the flat surface. The vapor source consisted of a 10 mm diameter and 10 mm tall can with approximately 10 g of gelatin with 0.1...Fabrication and characterization of gelatin -based test materials for verification of trace contraband vapor detectors. Analyst 135, 2573-2578 (2010

Guidelines for CubeSat's Thermal Design

NASA Technical Reports Server (NTRS)

Rodriguez-Ruiz, Juan; Patel, Deepak

2015-01-01

Thermal and Fluids Analysis Workshop 2015, Silver Spring, MD. NCTS 19104-15. What does it take to thermally designlow cost, low mass cubesats? What are the differences in the approach when you compare with large scale missions?What additional risk is acceptable? What is the approach to hardware? How is the testing campaign run? These aresome of the questions that will be addressed in this course, which is designed to equip the attendees to support thedevelopment of cubesats at their organization.

Proceedings of the NITINOL Heat Engine Conference, 26-27 September 1978, Silver Spring, Maryland

DTIC Science & Technology

1978-09-27

allowed us to design, build, and test various engine designs, while exploring advanced concepts with computer modeling of motor dynamics and heat exchange ...exclude the effects of element geometi y and other material parameters which affect the heat exchange rate and kinetics of the SRP. 5-3...is in Rference 8. 13. In the present work we exclude the effects of element geometry and other material parameters which affect the heat exchange

Mechanism of Chemical Action and Treatment of Cyanide Poisoning.

DTIC Science & Technology

1984-10-01

the sample was determined in an Aminco- Bowman Spectrophotofluorometer (American Instrument Co., Silver Spring, MD) at an emission wavelength of 420...S2 0 3 10.0 0.35 ± 0.13 0.44 ± 0.06 0.64 ± 0.38 0.74 ± 0.± 0 NaNOr + 5.0 0.42 ± ,.𔄁 0.e5 ± 0.30 0.74 ± 0.39 0.79 = 0.33 Na-S0, 𔃺.0 a Rat

2014 Materials Research Society (MRS) Spring Meeting (4/21-25/14), Moscone West Convention Center, San Francisco CA

DTIC Science & Technology

2015-04-02

optical communications . Yet, the lack of a general theoretical framework able to anticipate over the whole visible spectrum and with high accuracy the...detection, as well as new avenues for largely transparent tunable isolators for optical communications . [1] G. Armelles et al., Adv. Optical Mater. 2013...coefficients that are simultaneously equal to or greater than unity can all be achieved with increasing PT-symmetric potentials. We then use a dyadic Green’s

Dynamic Burning Effects in the Combustion of Solid Propellants with Cracks, and the Use of Granular Bed Combustion Models

DTIC Science & Technology

1980-12-01

Detachment, White Oak Laboratory, Silver Spring Code 240, Sigmund Jacobs (1) G. B. Wilmot (1) 1 Naval Underwater Systems Center, Newport (Code 5B331...Models by Kenneth K. Kuo and Mridul Kumar Systems Associates DTIC Pennsylvanir State University ELECTE for the APR 8 1981 Research Department B...ACTIVTY OF THE NAVAL MATERIAL COMMAND FOREWORD This is the final report for a research program conducted by Systems Associates, Pennsylvania State

Luminescence Quenching of the Tris(2,2’-bipyrazine) Ruthenium(II) Cation, and Its Monoprotonated Complex.

DTIC Science & Technology

1984-01-01

10 ROA ENT. POCT ASK B.E REPMNGORNTIDOCUMEANDTDR RATIO PAGE UNI UES Yorkhniverity Chemistr Deparment . CNT OL IN OFaIC NAMEtle AND TYPE 2. REPORT &TE0...Alternatively, in view of the high negative charge on the quencher and high positive charge on the excited ruthenium species, some kind of exciplex may be...Southampton S09 5NH White Oak Laboratory United Kingdom Silver Spring, Maryland 20910 Dr. T. Katan Dr. Sam Perone Lockheed Missiles and Chemistry

Effect of Cloud Fraction on Near-Cloud Aerosol Behavior Based on MODIS and CALIPSO Observations

NASA Technical Reports Server (NTRS)

Marshak, A.; Varnai, T.; Yang, W.

2015-01-01

Organizers of the MODIS-VIIRS Science Team Meeting, held May 18-22, 2015 in Silver Spring, MD plan to post the presentations and posters to the NASA MODIS website: http:modis.gsfc.nasa.govsci_teammeetings201505index.php. The MODIS Science Team Meeting is held twice a year, so that the members of the science team may assemble and discuss data they have collected, ideas they have formed, and future issues that apply to the MODIS Mission.

Analytical Methodology Used To Assess/Refine Observatory Thermal Vacuum Test Conditions For the Landsat 8 Data Continuity Mission

NASA Technical Reports Server (NTRS)

Fantano, Louis

2015-01-01

Thermal and Fluids Analysis Workshop Silver Spring, MD NCTS 21070-15 The Landsat 8 Data Continuity Mission, which is part of the United States Geologic Survey (USGS), launched February 11, 2013. A Landsat environmental test requirement mandated that test conditions bound worst-case flight thermal environments. This paper describes a rigorous analytical methodology applied to assess refine proposed thermal vacuum test conditions and the issues encountered attempting to satisfy this requirement.

Proceedings of the DOD Symposium on Evolution of Military Medical Entomology

DTIC Science & Technology

2008-11-16

NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Armed Forces Pest Management Board,WRAMC Forest Glen Annex,BG 172, Forney Rd,Silver Spring...Rev. 8-98) Prescribed by ANSI Std Z39-18 Preface From the Director For the past several years, the Armed Forces Pest Management Board (AFPMB...of the war few are more vivid than those of the numerous little pests that, of one kind or another, day and night, year in and year out, foraged

Nitramine Composite Solid Propellant Modelling

DTIC Science & Technology

1989-07-01

nonshaded areas, Sox values of zero are calculated for the various configurations indicated. The upper shaded area corresponds to one- half cf the...results: QDX ST Q X P F -XP QX "X TsX - To Gs X+ + Cf l sT),X +(l-Xf) ,X (134) In the above equations, and in the ones that follow, the solid phase...Surface Warfare Center, White Oak Laboratory, Silver Spring Code R10, S. Jacobs (1) Code R16, Dr. G. B. Wilmot (1) 1 Naval Underwater Systems Center

Two-Phase Flow Instrumentation Review Group Meeting. Proceedings of Meeting Held in Silver Spring, Maryland on January 13-14, 1977

DTIC Science & Technology

1978-03-01

ADWRESS OInclud Zip Code) 10. PROJECTfTASK/WORK UNI1 VO. Same as 9. above. I1. CONTRACT NO. 13. TYPE OF REPORT PERIOD COVERED (inclusive dews ) Meeting...Discussion of basic principles. c. Lists of y-emitling tracers for gas ; for liquid; commercially available radioisotope milking systems; elements easily...factors) - single phase loops, full flow, (2) prototype calibration (a) gas -water loop, (b) geometry effect. (c) scaling. (3) proof testing - simulation of

Complete Genome Sequences of Zika Virus Strains Isolated from the Blood of Patients in Thailand (2014) and Philippines (2012)

DTIC Science & Technology

2016-03-09

Silver Spring, MD 20910, USA 11 3 Center for Genome Sciences, United States Army Medical Research Institute of Infectious 12 Diseases , 1425 Porter Street...Fort Detrick, Frederick, MD, 21702, USA 13 4 Department of Disease Control, Bureau of Epidemiology, Ministry of Public Health, 14 Nonthaburi...96 97 98 REFERENCES 99 1. Calvet G, Aguiar RS, Melo AS, Sampaio SA, de Filippis I, Fabri A, Araujo ES, de 100 Sequeira PC, de Mendonça MC

Development of a prototype flexible radiator system

NASA Technical Reports Server (NTRS)

Hixon, C. W.

1979-01-01

The radiator is a roll-up flexible panel with the transport fluid manifolds located at the ends of the 27 foot length. A total of fifty Teflon flow tubes are sandwiched between the layers of silver wire mesh and sealed in the Teflon film. The transport fluid flows from an inlet manifold through 25 panel flow tubes to the end of the radiator panel into a manifold which directs the fluid into the other 25 flow tubes on its return to the base of the radiator. Deployment/retraction of the flexible radiator panel is by low pressure inflation tubes (one along each side of the panel) which incorporate a flat spring. The spring supplies the retraction force to wind the radiator panel on a drum when the pressure in the inflation tubes is relieved. Room ambient deployment tests of the radiator panel were conducted to verify the inflation tube spring deployment, and retraction capability. The panel underwent a thermal vacuum, solar spectrum exposure test. After approximately 100 hours of solar exposure, post-test inspection revealed no structural or optical properties degraded.

Lanthanide-functionalized silver nanoparticles for detection of an anthrax biomarker and test paper fabrication

NASA Astrophysics Data System (ADS)

Tan, Hongliang; Li, Qian; Ma, Chanjiao; Song, Yonghai; Xu, Fugang; Chen, Shouhui; Wang, Li

2014-01-01

It is highly desirable to develop a simple and sensitive analytical method for detection of anthrax biomarker (dipicolinic acid, DPA) because of its dangerous nature. In this work, we developed a fluorescent sensor for DPA detection based on terbium ion-functionalized silver nanoparticles with an average size of 6.7 nm (AgNPs-Tb3+). The fluorescent intensity of Tb-DPA complex on the surface of AgNPs was two times higher than that of Tb-DPA complex alone in a solution phase due to the metal-enhanced fluorescence (MEF) effect of AgNPs. The proposed fluorescent sensor exhibits excellent selectivity and high sensitivity for DPA. Importantly, a test paper for DPA detection was fabricated for the first time by the integration of AgNPs-Tb3+ onto the nitrocellulose membrane. Owing to the MEF effect of AgNPs, the lowest detectable concentration of the test paper-integrated AgNPs-Tb3+ for DPA by naked eyes is 10 times lower than that of the test paper-integrated Tb3+ alone. We believe that the presented strategy may open up new avenues to the development of portable and robust-sensing platforms based on functional hybrid materials.

Modelling of the spring phenological phases of the Silver birch Betula pendula and Bird cherry Padus racemosa in Baltic region

NASA Astrophysics Data System (ADS)

Kalvāns, Andis; Kalvāne, Gunta; Bitāne, Māra; Cepīte-Frišfelde, Daiga; Sīle, Tija; Seņņikovs, Juris

2014-05-01

The air temperature is the strongest driving factor of the plant development during spring time in moderate climate conditions. However other factors such as the air temperature during the dormancy period and light conditions can play a role as well. The full potential of the recent and historical phenological observation data can be utilised by modelling tools. We have calibrated seven phenological models described in scientific literature to calculate the likely dates leaf unfolding and start of flowering of the Silver birch Betula pendula and bird cherry Padus racemosa (Kalvāns at al, accepted). Phenological observations are derived from voluntary observation network for period 1960-2009 in Latvia. The number of used observations for each phase range from 149 to 172. Air temperature data measured in meteorological stations closest to the corresponding phenological observation sites are obtained from Latvian Environment, Geology and Meteorology Centre. We used 33 random data subsamples for model calibration to produce a range of model coefficients enabling the estimation of the phenological model uncertainty. It is found that the best reproduction of the observational data are obtained using a simple linear degree day model considering daily minimum and maximum temperature and more complex sigmoidal model honouring the need for low temperatures for dormancy release (UniChill, Chuine, 2000). The median calibration base temperature in the degree day model for the silver birch leaf unfolding is 5.6°C and for start of the flowering 6.7°C; for the bird cherry the corresponding base temperatures are 3.2°C and 3.4°C. The calibrated models and air temperature archive data derived from the Danish Meteorological Institute is used to simulate the respective phase onset in the Estonia, Latvia and Lithuania in 2009. Significant regional differences between modelled phase onset times are observed. There is a wide regional variation of the model uncertainty as well, indicated by the confidence intervals calculated from the 33 model calibrations: in some regions all the coefficient sets give similar phase onset times (within two to three day interval) while on other cases the spread can be more than a weak. In the spring 2014 field campaign is planned to obtain considerable data set for leaf unfolding and start of flowering of the bird cherry in Estonia, Latvia and Lithuania. The data will be used to evaluate performance of phenological models driven by short, medium and long term air temperature forecasts. The research is supported by the European Union through the European Social Fund Mobilitas grant No MJD309. References Chuine, I. (2000). A unified model for budburst of trees. Journal of theoretical biology, 207 (3), 337-347 Kalvāns, A., Bitāne, M., Kalvāne, G., accepted. Forecasting plant phenology: evaluating the phenological models for Betula pendula and Padus racemosa spring phases, Latvia. International Journal of Biometeorology, accepted.

Mineral Resources of the Warm Springs Wilderness Study Area, Mohave County, Arizona

USGS Publications Warehouse

Gray, Floyd; Jachens, Robert C.; Miller, Robert J.; Turner, Robert L.; Knepper, Daniel H.; Pitkin, James A.; Keith, William J.; Mariano, John; Jones, Stephanie L.; Korzeb, Stanley L.

1986-01-01

At the request of the U.S. Bureau of Land Management, approximately 113,500 acres of the Warm Springs Wilderness Study Area (AZ-020-028/029) were evaluated for mineral resources and mineral resource potential. In this report, the area studied is referred to as the 'wilderness study area' or 'study area'; any reference to the Warm Springs Wilderness Study Area refers only to that part of the wilderness study area for which a mineral survey was requested. This study area is located in west-central Arizona. The U.S. Geological Survey and the U.S. Bureau of Mines conducted geological, geochemical, and geophysical surveys to appraise the identified mineral resources (known) and assess the mineral resource potential (undiscovered) of the study area. fieldwork for this report was carried out largely in 1986-1989. There is a 1-million short ton indicated subeconomic resource of clinoptilolite-mordenite zeolite and an additional inferred resource of 2 million short tons near McHeffy Butte, approximately 2 miles west of the study area. A perlite deposit in the southeast corner of the study area contains an inferred subeconomic resource totaling 13 million short tons. An inferred subeconomic resource of gold in 225 short tons of quartz having a grade of 0.01 8 troy ounces per short ton is present at the Cook mine, 0.5 miles west of the study area. The northwestern part of the Warm Springs Wilderness Study Area has high mineral resource potential for gold and silver. The south-central part of the study area has one area of moderate and one area north of this south-central part has low mineral resource potential for gold and silver in and near Warm Springs Canyon; the mineral resource potential for gold is also moderate in three small areas in the southern part and one area in the northeastern part of the study area. The mineral resource potential for zeolite is high for the area surrounding the McHeffy Butte prospect and for one area in the southern part of the study area. Two areas inside the south and southeast boundaries of the study area have high mineral resource potential for perlite. The potential for ka: olinite resources is moderate in two areas in the southern part of the study area. The southern part of the study area has low resource potential for perlite and zeolite. Geothermal energy resource potential of the study area is low. The study area has no resource potential for oil and gas.

Computational Study of Quasi-2D Liquid State in Free Standing Platinum, Silver, Gold, and Copper Monolayers.

PubMed

Yang, Li-Ming; Ganz, Ariel B; Dornfeld, Matthew; Ganz, Eric

2016-12-01

Recently, freestanding atomically thick Fe metal patches up to 10 atoms wide have been fabricated experimentally in tiny pores in graphene. This concept can be extended conceptually to extended freestanding monolayers. We have therefore performed ab initio molecular dynamics simulations to evaluate the early melting stages of platinum, silver, gold, and copper freestanding metal monolayers. Our calculations show that all four freestanding monolayers will form quasi-2D liquid layers with significant out-of-plane motion and diffusion in the plane. Remarkably, we observe a 4% reduction in the Pt most likely bond length as the system enters the liquid state at 2400 K (and a lower effective spring constant), compared to the system at 1200 and 1800 K. We attribute this to the reduced average number of bonds per atom in the Pt liquid state. We used the highly accurate and reliable Density Functional Theory (DFT-D) method that includes dispersion corrections. These liquid states are found at temperatures of 2400 K, 1050 K, 1600 K, and 1400 K for platinum, silver, gold, and copper respectively. The pair correlation function drops in the liquid state, while the bond orientation order parameter is reduced to a lesser degree. Movies of the simulations can be viewed online (see Supplementary Material).

[Effects of large bio-manipulation fish pen on community structure of crustacean zooplankton in Meiliang Bay of Taihu Lake].

PubMed

Ke, Zhi-Xin; Xie, Ping; Guo, Long-Gen; Xu, Jun; Zhou, Qiong

2012-08-01

In 2005, a large bio-manipulation pen with the stock of silver carp and bighead carp was built to control the cyanobacterial bloom in Meiliang Bay of Taihu Lake. This paper investigated the seasonal variation of the community structure of crustacean zooplankton and the water quality within and outside the pen. There were no significant differences in the environmental parameters and phytoplankton biomass within and outside the pen. The species composition and seasonal dynamics of crustacean zooplankton within and outside the pen were similar, but the biomass of crustacean zooplankton was greatly suppressed by silver carp and bighead carp. The total crustacean zooplankton biomass and cladocerans biomass were significantly lower in the pen (P < 0.05). In general, silver carp and bighead carp exerted more pressure on cladoceran species than on copepod species. A distinct seasonal succession of crustacean zooplankton was observed in the Bay. Many crustacean species were only dominated in given seasons. Large-sized crustacean (mainly Daphnia sp. and Cyclops vicnus) dominated in winter and spring, while small-sized species (mainly Bosmina sp., Ceriodaphnia cornuta, and Limnoithona sinensis) dominated in summer and autumn. Canonical correspondence analysis showed that water transparency, temperature, and phytoplankton biomass were the most important factors affecting the seasonal succession of the crustacean.

Mineral Resources of the Morey and Fandango Wilderness Study Areas, Nye County, Nevada

USGS Publications Warehouse

John, David A.; Nash, J. Thomas; Plouff, Donald; McDonnell, John R.

1987-01-01

The Morey (NV-060-191) and Fandango (NV-060-190) Wilderness Study Areas are located in the northern Hot Creek Range about 25 mi north of Warm Springs, Nev. At the request of the Bureau of Land Management, 46,300 acres of the Morey and Fandango Wilderness Study Areas were studied. In this report, the area studied is referred to as 'the wilderness study area', or simply 'the study area'. Geologic, geochemical, geophysical, and mineral surveys were conducted by the USGS and the USBM in 1984 to appraise the identified mineral resources and to assess the mineral resource potential of the study areas. These studies indicate that there are small identified resources of zinc, lead, and silver at the Lead Pipe property in the Fandango Wilderness Study Area, several areas of high potential for the occurrence of gold resources in the Fandango study area, small areas of low and moderate potential for the occurrence of silver, lead, and zinc resources in the Fandango study area, areas of moderate and high potential for the occurrence of silver, lead, and zinc resources in the Morey study area, and an area of low potential for copper, molybdenum, and tin in the Morey study area. Both study areas have low resource potential for petroleum, natural gas, uranium, and geothermal energy.

Flexible and stretchable power sources for wearable electronics

PubMed Central

Zamarayeva, Alla M.; Ostfeld, Aminy E.; Wang, Michael; Duey, Jerica K.; Deckman, Igal; Lechêne, Balthazar P.; Davies, Greg; Steingart, Daniel A.; Arias, Ana Claudia

2017-01-01

Flexible and stretchable power sources represent a key technology for the realization of wearable electronics. Developing flexible and stretchable batteries with mechanical endurance that is on par with commercial standards and offer compliance while retaining safety remains a significant challenge. We present a unique approach that demonstrates mechanically robust, intrinsically safe silver-zinc batteries. This approach uses current collectors with enhanced mechanical design, such as helical springs and serpentines, as a structural support and backbone for all battery components. We show wire-shaped batteries based on helical band springs that are resilient to fatigue and retain electrochemical performance over 17,000 flexure cycles at a 0.5-cm bending radius. Serpentine-shaped batteries can be stretched with tunable degree and directionality while maintaining their specific capacity. Finally, the batteries are integrated, as a wearable device, with a photovoltaic module that enables recharging of the batteries. PMID:28630897

Investigation of the mineral potential of the Clipper Gap, Lone Mountain-Weepah, and Pipe Spring plutons, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tingley, J.V.; Maldonado, F.

1983-09-15

The Clipper Gap pluton, composed mostly of quartz monzonite with minor granite, granodiorite, and crosscutting alaskite dikes, intrudes Paleozoic western facies strata. A narrow zone of contact metamorphism is present at the intrusive-sediment contact. No mineral production has been recorded from Clipper Gap, but quartz veins containing gold-silver-copper mineral occurrences have been prospected there from the late 1800's to the present. Areas of the Lone Mountain-Weepah plutons that were studied are located in Esmeralda County about 14 km west of Tonopah, Nevada. At Lone Mountain, a Cretaceous intrusive cuts folded Precambrian and Cambrian sediments. Lead-zinc ores have been mined frommore » small replacement ore bodies in the Alpine district, west of Lone Mountain. Copper and molybdenum occurrences have been found along the east flank of Lone Mountain, and altered areas were noted in intrusive outcrops around the south end of Lone Mountain. Mineral occurrences are widespread and varied with mining activity dating back to the 1860's. The Pipe Spring pluton study area is flanked by two important mining districts, Manhattan to the north and Belmont to the northeast. Mining activity at Belmont dates from 1865. Activity at Manhattan was mainly between 1907 and 1947, but the district is active at the present time (1979). Four smaller mining areas, Monarch, Spanish Springs, Baxter Spring, and Willow Springs, are within the general boundary of the area. The Pipe Spring pluton study area contains numerous prospects along the northern contact zone of the pluton. Tungsten-bearing veins occur within the pluton near Spanish Springs, with potential for gold-tungsten placer in the Ralston Valley. Nickel and associated metals occur at Willow Spring and Monarch Ranch, where prospects may be associated with the margin of the Big Ten Peak Caldera.« less

Introduction to Loop Heat Pipes

NASA Technical Reports Server (NTRS)

Ku, Jentung

2015-01-01

This is the presentation file for the short course Introduction to Loop Heat Pipes, to be conducted at the 2015 Thermal Fluids and Analysis Workshop, August 3-7, 2015, Silver Spring, Maryland. This course will discuss operating principles and performance characteristics of a loop heat pipe. Topics include: 1) pressure profiles in the loop; 2) loop operating temperature; 3) operating temperature control; 4) loop startup; 4) loop shutdown; 5) loop transient behaviors; 6) sizing of loop components and determination of fluid inventory; 7) analytical modeling; 8) examples of flight applications; and 9) recent LHP developments.

Introduction to Heat Pipes

NASA Technical Reports Server (NTRS)

Ku, Jentung

2015-01-01

This is the presentation file for the short course Introduction to Heat Pipes, to be conducted at the 2015 Thermal Fluids and Analysis Workshop, August 3-7, 2015, Silver Spring, Maryland. NCTS 21070-15. Course Description: This course will present operating principles of the heat pipe with emphases on the underlying physical processes and requirements of pressure and energy balance. Performance characterizations and design considerations of the heat pipe will be highlighted. Guidelines for thermal engineers in the selection of heat pipes as part of the spacecraft thermal control system, testing methodology, and analytical modeling will also be discussed.

Proceedings of the U.S. Air Force and The Federal Republic of Germany Data Exchange Agreement Meeting (9th), Viscous and Interacting Flow Field Effects Held at Silver Spring, Maryland on 9-10 May 1984,

DTIC Science & Technology

1984-08-01

found in References 1-3. 2. Modeling of Roughness Effects on Turbulent Flow In turbulent flow analysis , use of time-averaged equations leads to the...eddy viscosity and the mixing length which are important parameters used in current algebraic modeling of the turbulence shear term. Two different ...surfaces with three-dimensional (distributed) roughness elements. Calculations using the present model have been compared with experimental data from

Proceedings of the DoD Information Analysis Center Conference (3rd) Held at Naval Surface Weapons Center, White Oak, Silver Spring, Maryland, 8-9 December 1981,

DTIC Science & Technology

1982-12-09

34 .: .. . .2 .., - " SESSION II Mr. Jerome Persh, Staff Specialist for Materials and qtructures, OUSDR&E Mr. Charles Miller. Program Director for Federal...Control Division, Office of Assistant Secretary of Defense Management Systems Mr. Jerome Pearson, Air Force Flight Dynamics Laboratory Mr. Harry Pebly...your support and I solicit your assistance. The selection of subjects for the Conference is an excellent one; we are all going to learn a lot here. The

Expression of HLA Class II Molecules in Humanized NOD.Rag1KO.IL2RgcKO Mice is Critical for Development and Function of Human T and B Cells

DTIC Science & Technology

2011-05-17

HSC-infused DRAG and control mice were immunized with 1 flocculation unit of TT vaccine ( Sanofi Pasteur) by the intramuscular route, and the titers... Vaccine Program, Naval Medical Research Center/Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America, 2 Department...human vaccines prior to clinical trials. However, current humanized mouse models show sub-optimal human T cell reconstitution and limited ability to

The effect of increased air humidity on fine root and rhizome biomass and turnover of silver birch forest ecosystem - a FAHM study.

NASA Astrophysics Data System (ADS)

Ostonen, I.; Kupper, P.; Sõber, J.; Aosaar, J.; Varik, M.; Lõhmus, K.

2012-04-01

A facility for free air humidity manipulation (FAHM) was established to investigate the effect of increased air humidity on belowground biomass and turnover in silver birch (Betula pendula Roth.) forest ecosystems with respect to rising air humidity predicted for Northern Europe. Fine root and rhizomes are short-lived and recognized as the most important component contributing to below-ground C fluxes in forests. The FAHM system enables air relative humidity to be increased on average 7 units (%) over the ambient level during mist fumigation. The experimental site contains humidified (H) and control (C) plots; each plot contains sectors with diverse "forest" understory and early successional grasses. The trees were planted in 2006, humidification started in spring 2008, and soil cores to study fine root and rhizome biomass and turnover were taken in 2007, 2009 and 2010. In July 2009, total fine root and rhizome biomass was 8 tons per ha in C and 16 tons per ha in H plots. The roots of understory formed 86% in C and 93% H plots, respectively. Our preliminary data suggest that the increased humidity affected more the roots of understory plants: fine root and rhizome biomass and production increased approximately twice by increasing air humidity. However, the tendency was similar for fine root biomass and production of silver birch. Fine root turnover speeded up for both silver birch and understory roots in H plots. Hence, changes in air humidity can significantly affect forest carbon cycling.

Structural Inventory of Great Basin Geothermal Systems and Definition of Favorable Structural Settings

DOE Data Explorer

Faulds, James E.

2013-12-31

Over the course of the entire project, field visits were made to 117 geothermal systems in the Great Basin region. Major field excursions, incorporating visits to large groups of systems, were conducted in western Nevada, central Nevada, northwestern Nevada, northeastern Nevada, east‐central Nevada, eastern California, southern Oregon, and western Utah. For example, field excursions to the following areas included visits of multiple geothermal systems: - Northwestern Nevada: Baltazor Hot Spring, Blue Mountain, Bog Hot Spring, Dyke Hot Springs, Howard Hot Spring, MacFarlane Hot Spring, McGee Mountain, and Pinto Hot Springs in northwest Nevada. - North‐central to northeastern Nevada: Beowawe, Crescent Valley (Hot Springs Point), Dann Ranch (Hand‐me‐Down Hot Springs), Golconda, and Pumpernickel Valley (Tipton Hot Springs) in north‐central to northeast Nevada. - Eastern Nevada: Ash Springs, Chimney Hot Spring, Duckwater, Hiko Hot Spring, Hot Creek Butte, Iverson Spring, Moon River Hot Spring, Moorman Spring, Railroad Valley, and Williams Hot Spring in eastern Nevada. - Southwestern Nevada‐eastern California: Walley’s Hot Spring, Antelope Valley, Fales Hot Springs, Buckeye Hot Springs, Travertine Hot Springs, Teels Marsh, Rhodes Marsh, Columbus Marsh, Alum‐Silver Peak, Fish Lake Valley, Gabbs Valley, Wild Rose, Rawhide‐ Wedell Hot Springs, Alkali Hot Springs, and Baileys/Hicks/Burrell Hot Springs. - Southern Oregon: Alvord Hot Spring, Antelope Hot Spring‐Hart Mountain, Borax Lake, Crump Geyser, and Mickey Hot Spring in southern Oregon. - Western Utah: Newcastle, Veyo Hot Spring, Dixie Hot Spring, Thermo, Roosevelt, Cove Fort, Red Hill Hot Spring, Joseph Hot Spring, Hatton Hot Spring, and Abraham‐Baker Hot Springs. Structural controls of 426 geothermal systems were analyzed with literature research, air photos, google‐Earth imagery, and/or field reviews (Figures 1 and 2). Of the systems analyzed, we were able to determine the structural settings of more than 240 sites. However, we found that many “systems” consisted of little more than a warm or hot well in the central part of a basin. Such “systems” were difficult to evaluate in terms of structural setting in areas lacking in geophysical data. Developed database for structural catalogue in a master spreadsheet. Data components include structural setting, primary fault orientation, presence or absence of Quaternary faulting, reservoir lithology, geothermometry, presence or absence of recent magmatism, and distinguishing blind systems from those that have surface expressions. Reviewed site locations for all 426 geothermal systems– Confirmed and/or relocated spring and geothermal sites based on imagery, maps, and other information for master database. Many systems were mislocated in the original database. In addition, some systems that included several separate springs spread over large areas were divided into two or more distinct systems. Further, all hot wells were assigned names based on their location to facilitate subsequent analyses. We catalogued systems into the following eight major groups, based on the dominant pattern of faulting (Figure 1): - Major normal fault segments (i.e., near displacement maxima). - Fault bends. - Fault terminations or tips. - Step‐overs or relay ramps in normal faults. - Fault intersections. - Accommodation zones (i.e., belts of intermeshing oppositely dipping normal faults), - Displacement transfer zones whereby strike‐slip faults terminate in arrays of normal faults. - Transtensional pull‐aparts. These settings form a hierarchal pattern with respect to fault complexity. - Major normal faults and fault bends are the simplest. - Fault terminations are typically more complex than mid‐segments, as faults commonly break up into multiple strands or horsetail near their ends. - A fault intersection is generally more complex, as it generally contains both multiple fault strands and can include discrete di...

How important is exact knowledge of preferential flowpath locations and orientations for understanding spatiotemporally integrated spring hydrologic and transport response?

NASA Astrophysics Data System (ADS)

Henson, W.; De Rooij, R.; Graham, W. D.

2016-12-01

The Upper Floridian Aquifer is hydrogeologically complex; limestone dissolution has led to vertical and horizontal preferential flow paths. Locations of karst conduits are unknown and conduit properties are poorly constrained. Uncertainty in effects of conduit location, size, and density, network geometry and connectivity on hydrologic and transport responses is not well quantified, leading to limited use of discrete-continuum models that incorporate conduit networks for regional-scale hydrologic regulatory models. However, conduit networks typically dominate flow and contaminant transport in karst aquifers. We evaluated sensitivity of simulated water and nitrate fluxes and flow paths to karst conduit geometry in a springshed representative of Silver Springs, Florida, using a novel calcite dissolution conduit-generation algorithm coupled with a discrete-continuum flow and transport model (DisCo). Monte Carlo simulations of conduit generation, groundwater flow, and conservative solute transport indicate that, if a first magnitude spring system conduit network developed (i.e., spring flow >2.8 m3/s), the uncertainty in hydraulic and solute pulse response metrics at the spring vent was minimally related to locational uncertainty of network elements. Across the ensemble of realizations for various distributions of conduits, first magnitude spring hydraulic pulse metrics (e.g., steady-flow, peak flow, and recession coefficients) had < 0.01 coefficient of variation (CV). Similarly, spring solute breakthrough curve moments had low CV (<0.08); peak arrival had CV=0.06, mean travel time had CV=0.05, and travel time standard deviation had CV=0.08. Nevertheless, hydraulic and solute pulse response metrics were significantly different than those predicted by an equivalent porous-media model. These findings indicate that regional-scale decision models that incorporate karst preferential flow paths within an uncertainty framework can be used to better constrain aquifer-vulnerability estimates, despite lacking information about actual conduit locations.

A survey of rural hospitals' perspectives on health information technology outsourcing.

PubMed

Johnson, Nicholas; Murphy, Alison; McNeese, Nathan; Reddy, Madhu; Purao, Sandeep

2013-01-01

A survey of rural hospitals was conducted in the spring of 2012 to better understand their perspectives on health information technology (HIT) outsourcing and the role that hospital-to-hospital HIT partnerships (HHPs) can play as an outsourcing mechanism. The survey sought to understand how HHPs might be leveraged for HIT implementation, as well as the challenges with forming them. The results suggest that HHPs have the potential to address rural hospitals' slow rate of HIT adoption, but there are also challenges to creating these partnerships. These issues, as well as avenues for further research, are then discussed.

A Survey of Rural Hospitals’ Perspectives on Health Information Technology Outsourcing

PubMed Central

Johnson, Nicholas; Murphy, Alison; McNeese, Nathan; Reddy, Madhu; Purao, Sandeep

2013-01-01

A survey of rural hospitals was conducted in the spring of 2012 to better understand their perspectives on health information technology (HIT) outsourcing and the role that hospital-to-hospital HIT partnerships (HHPs) can play as an outsourcing mechanism. The survey sought to understand how HHPs might be leveraged for HIT implementation, as well as the challenges with forming them. The results suggest that HHPs have the potential to address rural hospitals’ slow rate of HIT adoption, but there are also challenges to creating these partnerships. These issues, as well as avenues for further research, are then discussed. PMID:24551373

Physical Security Modeling for the Shipboard Nuclear Weapons Security Program,

DTIC Science & Technology

1982-04-01

I AOA1IR 396 NAVAL SURFACE WEAPONS CENTER SILVER SPRING MO F/G 15/3 PHYSICAL SECURITY MODELING FOR THE SHIPROARD NUCLEAR WEAPONS SE--ETEEU) APR A2 E ...WEAPONS SECURITY )PROGRAM 0% BY E . G. JACOUES D. L BARTUSEK R. W. MONROE M. S. SCHWARTZ WEAPONS SYSTEMS DEPARTMENT 1 APRIL 1982 A4pm lvW for p uic r...ASSIPICATIO N O F Tb IS PAGE t’W "mu Dat e E DLeT R)....... t READ W~STRUCTIoNs’ REPORT DOCUMENTATION PAGE BEFORE COMPLETNG FORM4 . REPiQRT NUM1e[i ja. VT

Life testing of secondary silver-zinc cells for the orbiting maneuvering vehicle

NASA Technical Reports Server (NTRS)

Brewer, Jeffrey C.; Doreswamy, Rajiv; Jackson, Lorna G.

1990-01-01

Over the past 5 years, extensive testing has been performed at the Marshall Space Flight Center (MSFC) on a variety of secondary (rechargeable) silver-zinc (Ag-Zn) cells for the Orbital Maneuvering Vehicle (OMV). The first tests performed were to determine the feasibility of using such a cell in a long-life (18-month), low-Earth-orbit (LEO) application. Results from these tests were promising, so testing continued with a 250-Ah cell that was specifically designed for this type of application. Once again, results from the tests were promising. Following a review of the data from these previous tests, slight modifications to the 250-Ah design were necessary to alleviate problem areas. Currently, MSFC is testing a 350-Ah design that has incorporated these changes and is the baseline design for the OMV. This test began in mid-November, 1989, and will be complete in the spring of 1991, barring any substantial offline time. A report is presented on the preliminary results from the first few months of this test and they are compared to results obtained in previous tests done at MFSC.

Hydrogeology, water quality, and potential for contamination of the Upper Floridan aquifer in the Silver Springs ground-water basin, central Marion County, Florida

USGS Publications Warehouse

Phelps, G.G.

1994-01-01

The Upper Floridan aquifer, composed of a thick sequence of very porous limestone and dolomite, is the principal source of water supply in the Silver Springs ground-water basin of central Marion County, Florida. The karstic nature of the local geology makes the aquifer susceptible to contaminants from the land surface. Contaminants can enter the aquifer by seepage through surficial deposits and through sinkholes and drainage wells. Potential contaminants include agricultural chemicals, landfill leachates and petroleum products from leaking storage tanks and accidental spills. More than 560 sites of potential contamination sources were identified in the basin in 1990. Detailed investigation of four sites were used to define hydrologic conditions at representative sites. Ground-water flow velocities determined from dye trace studies ranged from about 1 foot per hour under natural flow conditions to about 10 feet per hour under pumping conditions, which is considerably higher than velocities estimated using Darcy's equation for steady-state flow in a porous medium. Water entering the aquifer through drainage wells contained bacteria, elevated concentrations of nutrients, manganese and zinc, and in places, low concentrations of organic compounds. On the basis of results from the sampling of 34 wells in 1989 and 1990, and from the sampling of water entering the Upper Floridan aquifer through drainage wells, there has been no widespread degradation of water quality in the study area. In an area of karst, particularly one in which fracture flow is significant, evaluating the effects from contaminants is difficult and special care is required when interpolating hydrogeologic data from regional studies to a specific. (USGS)

Variation in wind and piscivorous predator fields affecting the survival of Atlantic salmon, Salmo salar, in the Gulf of Maine

USGS Publications Warehouse

Friedland, K.D.; Manning, J.P.; Link, Jason S.; Gilbert, J.R.; Gilbert, A.T.; O'Connell, A.F.

2012-01-01

Observations relevant to the North American stock complex of Atlantic salmon, Salmo salar L., suggest that marine mortality is influenced by variation in predation pressure affecting post-smolts during the first months at sea. This hypothesis was tested for Gulf of Maine (GOM) stocks by examining wind pseudostress and the distribution of piscivorous predator fields potentially affecting post-smolts. Marine survival has declined over recent decades with a change in the direction of spring winds, which is likely extending the migration of post-smolts by favouring routes using the western GOM. In addition to changes in spring wind patterns, higher spring sea surface temperatures have been associated with shifting distributions of a range of fish species. The abundance of several pelagic piscivores, which based on their feeding habits may predate on salmon post-smolts, has increased in the areas that serve as migration corridors for post-smolts. In particular, populations of silver hake, Merluccius bilinearis (Mitchell), red hake, Urophycis chuss (Walbaum), and spiny dogfish, Squalus acanthias L., increased in size in the portion of the GOM used by post-smolts. Climate variation and shifting predator distributions in the GOM are consistent with the predator hypothesis of recruitment control suggested for the stock complex.

Essential Oils from Different Plant Parts of Eucalyptus cinerea F. Muell. ex Benth. (Myrtaceae) as a Source of 1,8-Cineole and Their Bioactivities

PubMed Central

Silva, Sayonara Mendes; Abe, Simone Yae; Murakami, Fábio Seigi; Frensch, Gustavo; Marques, Francisco A.; Nakashima, Tomoe

2011-01-01

Eucalyptus cinerea, known as silver dollar tree, has few descriptions in traditional medicine. Chemical composition and antimicrobial properties of the essential oils of leaves, flowers and fruits, collected seasonally, were determined by GC/MS and disk diffusion/MIC, respectively. 1,8-Cineole was the main compound, particularly in fresh leaves—Spring (74.98%), dried leaves—Spring (85.32%), flowers—Winter (78.76%) and fruits—Winter (80.97%). Other compounds were found in the aerial parts in all seasons: α-pinene (2.41% to 10.13%), limonene (1.46% to 4.43%), α-terpineol (1.73% to 11.72%), and α-terpinyl acetate (3.04% to 20.44%). The essential oils showed antimicrobial activities against bacteria and yeasts, with the best results being found for the dried autumn and winter leaves oils (MIC < 0.39 mg/mL) against Streptococcus pyogenes. For the other tested microorganisms the following MIC results were found: Staphylococcus aureus— Dried leaves oil from summer (0.78 mg/mL), Pseudomonas aeruginosa—Flowers oil from autumn and fruits oil from winter (1.56 mg/mL) and Candida albicans—Flowers oil from autumn and fruits oils from winter and spring (0.78 mg/mL). PMID:26791641

I Situ Surface X-Ray Diffraction Studies of Electrochemically Deposited Monolayers

NASA Astrophysics Data System (ADS)

Yee, Dennis

1995-01-01

In situ x-ray diffraction has been used to determine the detailed atomic structure of electrochemically deposited lead, thallium, and bismuth monolayers on the silver (111) electrode surface. A review of our previously published lead and thallium monolayer results and the first in situ surface x-ray crystallographic study of the bismuth monolayer structure is presented. The crystallographic analysis of the bismuth Bragg rod intensities and the interference between the bismuth Bragg rod and silver crystal truncation rod scattering were used to determine the detailed atomic structure of the bismuth on silver (111) system at the liquid-solid interface. Our previous in situ x-ray diffraction studies showed that the bismuth monolayer lattice is rectangular and uniaxially incommensurate with the underlying hexagonal silver surface. A crystallographic analysis of the measured structure factor magnitudes reveals that the monolayer forms chains of atoms on the silver surface, similar to the bulk Bi(110)_{rh} plane, with a near neighbor distance of 3.12 +/- 0.01 A and a bond angle of 93 +/- 1^circ, consistent with the bulk Bi(110) _{rh} plane values. The crystallographic refinement also shows that the bismuth monolayer atoms are anisotropically disordered with a rms disorder of 0.25 +/- 0.03 A in the incommensurate direction and 0.09 +/- 0.03 A rms in the commnensurate direction. The interference between the Bi(20) Bragg rod and the Ag(10L)_ {h} crystal truncation rod scattering reveals that one set of bismuth atoms is registered near the bridge sites of the silver (111) surface while another set is registered near the 3-fold hollow sites. In addition, the Bi-Ag d-spacing (3.1 +/- 0.1 A) is found to be consistent with the bulk bismuth near neighbor distance. The bismuth z-direction rms disorder (1.01 +/- 0.08 A) is found to be dominated by the roughness of the underlying silver (sigma_{Ag} = 0.9 +/- 0.1 A rms). Using the estimated bismuth-bismuth spring constant of 1.41 +/- 0.07 eV/A^2 from our measured bismuth two-dimensional compressibility, two simple models are used to try and understand the origin of the anisotropic disorder. A simple two-dimensional isotropic thermal fluctuation model shows that thermal fluctuations are not large enough to account for all of the measured excess disorder in the incommensurate direction. A simple one-dimensional Frenkel-Kontorova model shows that the substrate-induced disorder can account for the anisotropic disorder, assuming a substrate sinusoidal potential strength of 0.35 +/- 0.02 eV.

Water quality and quantity of selected springs and seeps along the Colorado River corridor, Utah and Arizona: Arches National Park, Canyonlands National Park, Glen Canyon National Recreation Area, and Grand Canyon National Park, 1997-98

USGS Publications Warehouse

Taylor, Howard E.; Spence, John R.; Antweiler, Ronald C.; Berghoff, Kevin; Plowman, Terry I.; Peart, Dale B.; Roth, David A.

2004-01-01

The U.S. Geological Survey, in cooperation with the National Park Service conducted an intensive assessment of selected springs along the Colorado River Corridor in Arches National Park, Canyonlands National Park, Glen Canyon National Recreation Area, and Grand Canyon National Park in 1997 and 1998, for the purpose of measuring and evaluating the water quality and quantity of the resource. This study was conducted to establish baseline data for the future evaluation of possible effects from recreational use and climate change. Selected springs and seeps were visited over a study period from 1997 to 1998, during which, discharge and on-site chemical measurements were made at selected springs and seeps, and samples were collected for subsequent chemical laboratory analysis. This interdisciplinary study also includes simultaneous studies of flora and fauna, measured and sampled coincidently at the same sites. Samples collected during this study were transported to U.S. Geological Survey laboratories in Boulder, Colorado, where analyses were performed using state-of-the-art laboratory technology. The location of the selected springs and seeps, elevation, geology, aspect, and onsite measurements including temperature, discharge, dissolved oxygen, pH, and specific conductance, were recorded. Laboratory analyses include determinations for alkalinity, aluminum, ammonium (nitrogen), antimony, arsenic, barium, beryllium, bismuth, boron, bromide, cadmium, calcium, cerium, cesium, chloride, chromium, cobalt, copper, dissolved inorganic carbon, dissolved organic carbon, dysprosium, erbium, europium, fluoride, gadolinium, holmium, iodine, iron, lanthanum, lead, lithium, lutetium, magnesium, manganese, mercury, molybdenum, neodymium, nickel, nitrate (nitrogen), nitrite (nitrogen), phosphate, phosphorus, potassium, praseodymium, rhenium, rubidium, samarium, selenium, silica, silver, sodium, strontium, sulfate, tellurium, terbium, thallium, thorium, thulium, tin, titanium, tungsten, uranium, vanadium, yttrium, ytterbium, zinc, and zirconium in these springs and seeps. Biological observations include physical setting, vegetation, invertebrate habitats, and invertebrate microhabitats.

Tailoring plasmonic properties of nanobeam composites by the sliding disorder

NASA Astrophysics Data System (ADS)

Gric, Tatjana; Hess, Ortwin

2017-11-01

Nanobeam composites are important for designing sensing, nonlinear, and emission functionalities. Here, we describe a method for tuning the plasmonic properties of a silver nanobeam-based metamaterial. Such metamaterials open the wide avenues for a variety of applications in the fields of bio- and chemical sensing, nonlinearity enhancement, and fluorescence control. Specifically, we present the boundary between two nanobeam composites stacked together and exhibiting the sliding disorder. The modes are tunable. We simulated the solutions of surface plasmon polaritons (SPP) modes and their propagations. The configuration proposed here makes a breakthrough of the conventional configuration allowing for optimizations of SPP properties and making SPP application more flexible in practices. The wide plasmonic tuning range of nanobeam composites makes them promising in metamaterial-based optoelectronic devices. The plasma frequency is found to be tailored by the sliding disorder.

Waterlogging in late dormancy and the early growth phase affected root and leaf morphology in Betula pendula and Betula pubescens seedlings.

PubMed

Wang, Ai-Fang; Roitto, Marja; Sutinen, Sirkka; Lehto, Tarja; Heinonen, Jaakko; Zhang, Gang; Repo, Tapani

2016-01-01

The warmer winters of the future will increase snow-melt frequency and rainfall, thereby increasing the risk of soil waterlogging and its effects on trees in winter and spring at northern latitudes. We studied the morphology of roots and leaves of 1-year-old silver birch (Betula pendula Roth) and pubescent birch (Betula pubescens Ehrh.) seedlings exposed to waterlogging during dormancy or at the beginning of the growing season in a growth-chamber experiment. The experiment included 4-week dormancy (Weeks 1-4), a 4-week early growing season (Weeks 5-8) and a 4-week late growing season (Weeks 9-12). The treatments were: (i) no waterlogging, throughout the experiment ('NW'); (ii) 4-week waterlogging during dormancy (dormancy waterlogging 'DW'); (iii) 4-week waterlogging during the early growing season (growth waterlogging 'GW'); and (iv) 4-week DW followed by 4-week GW during the early growing season ('DWGW'). Dormancy waterlogging affected the roots of silver birch and GW the roots and leaf characteristics of both species. Leaf area was reduced in both species by GW and DWGW. In pubescent birch, temporarily increased formation of thin roots was seen in root systems of GW seedlings, which suggests an adaptive mechanism with respect to excess soil water. Additionally, the high density of non-glandular trichomes and their increase in DWGW leaves were considered possible morphological adaptations to excess water in the soil, as was the constant density of stem lenticels during stem-diameter growth. The higher density in glandular trichomes of DWGW silver birch suggests morphological acclimation in that species. The naturally low density of non-glandular trichomes, low density of stem lenticels in waterlogged seedlings and decrease in root growth seen in DWGW and DW silver birch seedlings explain, at least partly, why silver birch grows more poorly relative to pubescent birch in wet soils. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Official STS-67 preflight crew portrait

NASA Technical Reports Server (NTRS)

1995-01-01

Official STS-67 preflight crew portrait. In front are astronauts (left to right) Stephen S. Oswald, mission commander; Tamara E. Jernigan, payload commander; and William G. Gregory, pilot. In the back are (left to right) Ronald A. Parise, payload specialist; astronauts Wendy B. Lawrence, and John Grunsfeld, both mission specialists; and Samuel T. Durrance, payload specialist. Dr. Durrance is a research scientist in the Department of Physics and Astronomy at Johns Hopkins University, Baltimore, Maryland. Dr. Parise is a senior scientist in the Space Observatories Department, Computer Sciences Corporation, Silver Spring, Maryland. Both payload specialists flew aboard the Space Shuttle Columbia for STS-35/ASTRO-1 mission in December 1990.

BUFFALO PEAKS WILDERNESS STUDY AREA, COLORADO.

USGS Publications Warehouse

Hedlund, D.C.; Wood, R.H.

1984-01-01

Field investigations were conducted to evaluate the mineral-resource potential of the Buffalo Peaks Wilderness Study Area, Colorado. On the basis of this study there is a probable mineral-resource potential for silver vein and bedding replacement deposits along the Weston Pass fault zone, for hydrothermal vein-type uranium deposits in the vicinity of the Parkdale iron pit, and for gold vein deposits in the parts of the Granite and Four Mile districts that are within the wilderness study area. A probable barite resource potential occurs at Rough and Tumbling Creek and near Spring Creek on the east side of the study area. There is little promise for the occurrence of energy resources.

GILA WILDERNESS, NEW MEXICO.

USGS Publications Warehouse

Ratte, James C.; Stotelmeyer, Ronald B.

1984-01-01

Geologic, geochemical and geophysical indicators delineated during a study of the Gila Wilderness, New Mexico indicate that there are areas of probable and substantiated mineral-resource potential for gold, silver, tellurium, molybdenum, copper, lead, zinc, and fluorite. The areas which have resource potential lie along both sides of the western and southwestern boundaries of the wilderness, and adjacent to the access corridor to the Gila Cliff Dwellings National Monument in the eastern part of the wilderness. Areas marked by geothermal springs along Turkey Creek and Middle Fork of the Gila River have a probable potential for geothermal energy. No other energy-resource potential was identified within the study area.

Hysteresis, regime shifts, and non-stationarity in aquifer recharge-storage-discharge systems

NASA Astrophysics Data System (ADS)

Klammler, Harald; Jawitz, James; Annable, Michael; Hatfield, Kirk; Rao, Suresh

2016-04-01

Based on physical principles and geological information we develop a parsimonious aquifer model for Silver Springs, one of the largest karst springs in Florida. The model structure is linear and time-invariant with recharge, aquifer head (storage) and spring discharge as dynamic variables at the springshed (landscape) scale. Aquifer recharge is the hydrological driver with trends over a range of time scales from seasonal to multi-decadal. The freshwater-saltwater interaction is considered as a dynamic storage mechanism. Model results and observed time series show that aquifer storage causes significant rate-dependent hysteretic behavior between aquifer recharge and discharge. This leads to variable discharge per unit recharge over time scales up to decades, which may be interpreted as a gradual and cyclic regime shift in the aquifer drainage behavior. Based on field observations, we further amend the aquifer model by assuming vegetation growth in the spring run to be inversely proportional to stream velocity and to hinder stream flow. This simple modification introduces non-linearity into the dynamic system, for which we investigate the occurrence of rate-independent hysteresis and of different possible steady states with respective regime shifts between them. Results may contribute towards explaining observed non-stationary behavior potentially due to hydrological regime shifts (e.g., triggered by gradual, long-term changes in recharge or single extreme events) or long-term hysteresis (e.g., caused by aquifer storage). This improved understanding of the springshed hydrologic response dynamics is fundamental for managing the ecological, economic and social aspects at the landscape scale.

Effects of metal mining and milling on boundary waters of Yellowstone National Park, USA

USGS Publications Warehouse

Nimmo, D.R.; Willox, M.J.; Lafrancois, T.D.; Chapman, P.L.; Brinkman, S.F.; Greene, J.C.

1998-01-01

Aquatic resources in Soda Butte Creek within Yellowstone National Park, USA, continue to be threatened by heavy metals from historical mining and milling activities that occurred upstream of the park's boundary. This includes the residue of gold, silver, and copper ore mining and processing in the early 1900s near Cooke City, Montana, just downstream of the creek's headwaters. Toxicity tests, using surrogate test species, and analyses of metals in water, sediments, and macroinvertebrate tissue were conducted from 1993 to 1995. Chronic toxicity to test species was greater in the spring than the fall and metal concentrations were elevated in the spring with copper exceeding water quality criteria in 1995. Tests with amphipods using pore water and whole sediment from the creek and copper concentrations in the tissue of macroinvertebrates and fish also suggest that copper is the metal of concern in the watershed. In order to understand current conditions in Soda Butte Creek, heavy metals, especially copper, must be considered important factors in the aquatic and riparian ecosystems within and along the creek extending into Yellowstone National Park.

Applications of ERTS-1 data to landscape change in eastern Tennessee

NASA Technical Reports Server (NTRS)

Rehder, J. B. (Principal Investigator)

1973-01-01

The author has identified the following significant results. The analysis of landscape change in eastern Tennessee from ERTS-1 data is being derived from three avenues of experimentation and analysis: (1) a multi-stage sampling procedure utilizing ground and aircraft imagery for ground truth and control; (2) a densitometric and computer analytical experiment for the analysis of gray tone signatures and comparisons for landscape change detection and monitoring; and (3) an ERTS image enhancement procedure for the detection and analysis of photomorphic regions. Significant results include: maps of strip mining changes and forest inventory, watershed identification and delimitation, and agricultural regions derived from spring plowing patterns appearing on the ERTS-1 imagery.

Simulatng Sawtooth Mixers For Biofouling Mitigation

NASA Astrophysics Data System (ADS)

Waters, James; Balazs, Anna

2017-11-01

We demonstrate how a ridged surface can be used to generate vortices that will break up clusters of cells as they form. This offers an appealing avenue for fouling mitigation, as it relies on a physical mechanism without unintended environmental consequences. By adjusting the shape of these ridges, we can increase the effectiveness of the surface across a range of shear values. We represent such a system computationally using a hybrid of bulk fluid simulated via the lattice Boltzmann method, and deformable vesicles, representing cells, simulated via that lattice spring method. This simulation methodology allows us to rapidly implement and test different surface patterns, and explore how their parameters can most effectively deter the accumulation of biofilms.

Coordinative Alignment of Chiral Molecules to Control over the Chirality Transfer in Spontaneous Resolution and Asymmetric Catalysis.

PubMed

Xia, Zhengqiang; Jing, Xu; He, Cheng; Wang, Xiaoge; Duan, Chunying

2017-11-13

The production and availability of enantiomerically pure compounds that spurred the development of chiral technologies and materials are very important to the fine chemicals and pharmaceutical industries. By coordinative alignment of enantiopure guests in the metal‒organic frameworks, we reported an approach to control over the chirality of homochiral crystallization and asymmetric transformation. Synthesized by achiral triphenylamine derivatives, the chirality of silver frameworks was determined by the encapsulated enantiopure azomethine ylides, from which clear interaction patterns were observed to explore the chiral induction principles. With the changing of addition sequence of substrates, the enantioselectivity of asymmetric cycloaddition was controlled to verify the determinant on the chirality of the bulky MOF materials. The economical chirality amplification that merges a series of complicated self-inductions, bulk homochiral crystallization and enantioselective catalysis opens new avenues for enantiopure chemical synthesis and provides a promising path for the directional design and development of homochiral materials.

Time- and energy-efficient solution combustion synthesis of binary metal tungstate nanoparticles with enhanced photocatalytic activity.

PubMed

Thomas, Abegayl; Janáky, Csaba; Samu, Gergely F; Huda, Muhammad N; Sarker, Pranab; Liu, J Ping; van Nguyen, Vuong; Wang, Evelyn H; Schug, Kevin A; Rajeshwar, Krishnan

2015-05-22

In the search for stable and efficient photocatalysts beyond TiO2 , the tungsten-based oxide semiconductors silver tungstate (Ag2 WO4 ), copper tungstate (CuWO4 ), and zinc tungstate (ZnWO4 ) were prepared using solution combustion synthesis (SCS). The tungsten precursor's influence on the product was of particular relevance to this study, and the most significant effects are highlighted. Each sample's photocatalytic activity towards methyl orange degradation was studied and benchmarked against their respective commercial oxide sample obtained by solid-state ceramic synthesis. Based on the results herein, we conclude that SCS is a time- and energy-efficient method to synthesize crystalline binary tungstate nanomaterials even without additional excessive heat treatment. As many of these photocatalysts possess excellent photocatalytic activity, the discussed synthetic strategy may open sustainable materials chemistry avenues to solar energy conversion and environmental remediation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Plasmonic-enhanced targeted nanohealing of metallic nanostructures

NASA Astrophysics Data System (ADS)

Yang, Hangbo; Lu, Jinsheng; Ghosh, Pintu; Chen, Ziyao; Wang, Wei; Ye, Hui; Yu, Qian; Qiu, Min; Li, Qiang

2018-02-01

Healing defects of metallic structures is an essential procedure for manufacturing and maintaining integrated devices. Current nanocomposite-assisted microhealing methodologies are inadequate for nanoscopic applications because of their concomitant contamination and limited operation accuracy. In this paper, we propose an optically controllable targeted nanohealing technique by utilizing the plasmonic-enhanced photothermal effect. The healing of nanogaps between two silver nanowires (NWs) is achieved by increasing the incident laser power in steps. Partial connection of NWs can be readily obtained using this technique, while near-perfect connection of NWs with the same crystal orientations is obtained only when the lattices on the two opposing facets are matched after recrystallization. This non-contaminating nanohealing technique not only provides deeper insight into the heat/mass transfer assisted by plasmonic photothermal conversion in the nanoscale but also suggests avenues for recovering mechanical, electronic, and photonic properties of defected metallic nanodevices.

Enhanced Mechanical Stability of Gold Nanotips through Carbon Nanocone Encapsulation

PubMed Central

Cano-Marquez, Abraham G.; Schmidt, Wesller G.; Ribeiro-Soares, Jenaina; Gustavo Cançado, Luiz; Rodrigues, Wagner N.; Santos, Adelina P.; Furtado, Clascidia A.; Autreto, Pedro A.S.; Paupitz, Ricardo; Galvão, Douglas S.; Jorio, Ado

2015-01-01

Gold is a noble metal that, in comparison with silver and copper, has the advantage of corrosion resistance. Despite its high conductivity, chemical stability and biocompatibility, gold exhibits high plasticity, which limits its applications in some nanodevices. Here, we report an experimental and theoretical study on how to attain enhanced mechanical stability of gold nanotips. The gold tips were fabricated by chemical etching and further encapsulated with carbon nanocones via nanomanipulation. Atomic force microscopy experiments were carried out to test their mechanical stability. Molecular dynamics simulations show that the encapsulated nanocone changes the strain release mechanisms at the nanoscale by blocking gold atomic sliding, redistributing the strain along the whole nanostructure. The carbon nanocones are conducting and can induce magnetism, thus opening new avenues on the exploitation of transport, mechanical and magnetic properties of gold covered by sp2 carbon at the nanoscale. PMID:26083864

Installation Assessment of Headquarters, Walter Reed Army Medical Center, Washington, DC and Noncontiguous Sections Forest Glen, Silver Spring, Maryland and Glen Haven, Wheaton, Maryland.

DTIC Science & Technology

1984-06-01

percent Aerosol 30 12-oz cans Diazinon 47.5 percent EML 8 gal Malathion 3 percent solution 55 gal Propoxur 1 percent solution 2 gal Propoxur 2 percent...bait 2 5-lb cans Amino 2,4-D 49 percent EML 5 gal Metham-Sodiwa 33 percent solution I gal Carbaryl 41.5 percent flowable 2 lb Pival 0.025 percent 30 lb...Lice "o"pital 9,000 ft 2 DiasLnon 47.5 percent DII. 0.3 gal Wasps Residential 2,000 ft2 Carbaryl 60 percent Dust 0.21 lbs Plant Disease Open Brush I

Gila Wilderness, New Mexico

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ratte, J.C.; Stotelmeyer, R.B.

1984-01-01

Geologic, geochemical, and geophysical indicators delineated during a study of the Gila Wilderness by the USGS and USBM from 1968 to 1971 indicate that there are areas of probable and substantiated mineral-resource potential for gold, silver, tellurium, molybdenum, copper, lead, zinc, and fluorite. The areas which have resource potential lie along both sides of the western and southwestern boundaries of the wilderness, and adjacent to the access corridor to the Gila Cliff Dwellings National Monument in the eastern part of the wilderness. Areas marked by geothermal springs along Turkey Creek and the Middle Fork of the Gila River have amore » probable potential for geothermal energy. No other energy-resource potential was identified within the study area.« less

Borohydride Catalysis of Nitramine Thermal Decomposition and Combustion. 3. Literature Review and Wrap-Up Discussion of Possible Chemical Mechanisms

DTIC Science & Technology

1990-07-01

effect is quite well-known, and h s2 ble the subject of several workshops and cf a large number of reports. I2I The purpose of the present work is to...Their formation was rationalized in terms of the following mechanism: CF2 (N02) 2 + BH4 C--- F2 (N02) 2 D H+ +BH 3 0._• CPzNO 2 +NO 2 0 CF .2 (NO2...13 D. Mann G.B. Wilmot , R-16 R. Singleton Silver Spring, MD 20903-5000 R. Shaw P.O. Box 12211 5 Commander Research Triangle Park, NC Naval Research

Ancient hydrothermal ecosystems on earth: a new palaeobiological frontier.

PubMed

Walter, M R

1996-01-01

Thermal springs are common in the oceans and on land. Early in the history of the Earth they would have been even more abundant, because of a higher heat flow. A thermophilic lifestyle has been proposed for the common ancestor of extant life, and hydrothermal ecosystems can be expected to have existed on Earth since life arose. Though there has been a great deal of recent research on this topic by biologists, palaeobiologists have done little to explore ancient high temperature environments. Exploration geologists and miners have long known the importance of hydrothermal systems, as they are sources for much of our gold, silver, copper, lead and zinc. Such systems are particularly abundant in Archaean and Proterozoic successions. Despite the rarity of systematic searches of these by palaeobiologists, already 12 fossiliferous Phanerozoic deposits are known. Five are 'black smoker' type submarine deposits that formed in the deep ocean and preserve a vent fauna like that in the modern oceans; the oldest is Devonian. Three are from shallow marine deposits of Carboniferous age. As well as 'worm tubes', several of these contain morphological or isotopic evidence of microbial life. The oldest well established fossiliferous submarine thermal spring deposit is Cambro-Ordovician; microorganisms of at least three or four types are preserved in this. One example each of Carboniferous and Jurassic sub-lacustrine fossiliferous thermal springs are known. There are two convincing examples of fossiliferous subaerial hydrothermal deposits. Both are Devonian. Several known Proterozoic and Archaean deposits are likely to preserve a substantial palaeobiological record, and all the indications are that there must be numerous deposits suitable for study. Already it is demonstrable that in ancient thermal spring deposits there is a record of microbial communities preserved as stromatolites, microfossils, isotope distribution patterns and hydrocarbon biomarkers.

Water quality in the Ozark National Scenic Riverways, Missouri

USGS Publications Warehouse

Barks, James H.

1978-01-01

The Current River and its principal tributary, Jacks Fork, are the Ozark National Scenic Riverway's primary natural features. About 60 percent of the baseflow in the two streams is derived from the seven largest springs in the basin. The springs are supplied by diffuse contributions from the regional aquifer system and discrete inflows from sinkholes and losing streams, some of which are outside the Current River basin. Because the streams and springs are the primary attractions to the park, preservation of the physical, chemical, and biological quality and aesthetic appeal of the waters is important. From April 1973 to May 1975, water samples were collected from 19 wells, 7 large springs, 14 sites on the Current River, 7 sites on the Jacks Fork, and 5 tributaries to the Current River and Jacks Fork. Calcium, magnesium, and bicarbonate composed more than 90 percent of the total ionic composition of dissolved material in springs and streams and more than 95 percent in ground water, reflecting the dolomitic composition of the rocks. Dissolved-solids concentrations averaged 276 mg/L (milligrams per liter) in ground water and less than 200 mg/L in springs and streams. Total nitrate concentrations as N averaged 0.22 mg/L in ground water, 0.42 mg/L in springs, and less than 0.65 mg/L in streams. Minor element concentrations were generally low, but on one occasion anomalously high concentrations of total barium, lead, silver, and zinc were found in Blue Spring and the four stream-index stations. The only pesticides detected were 0.03 ?g/L (micrograms per liter) of 2,4-D, and 0.03 ?g/L of 2,4,5-T, and these were in the Current River below Montauk State Park during storm runoff. The streams were relatively free of sediment, except during periods of storm runoff. Fecal coliform and fecal streptococcus densities as high as 2,000 and 2,100 col/100 ml (colonies per 100 milliliters), respectively, were measured in the Jacks Fork downstream from horseback riding activities. Fecal coliform and fecal streptococcus densities of about 4,000 and 22,000 co11100 ml, respectively, were measured in the Current River during storm runoff. Otherwise, bacteria densities averaged less than 100 col/100 ml for fecal coliforms and 200 col/100 ml for fecal streptococci and appear to be relatively unaffected by swimming, camping, canoeing, and other recreational activities in and along streams. The aquatic biota in the Current River and Jacks Fork indicate that the streams generally are unaffected by pollution.

Diel changes in water chemistry in an arsenic-rich stream and treatment-pond system

USGS Publications Warehouse

Gammons, C.H.; Grant, T.M.; Nimick, D.A.; Parker, S.R.; DeGrandpre, M.D.

2007-01-01

Arsenic concentrations are elevated in surface waters of the Warm Springs Ponds Operable Unit (WSPOU), located at the head of the upper Clark Fork River Superfund site, Montana, USA. Arsenic is derived from historical deposition of smelter emissions (Mill and Willow Creeks) and historical mining and milling wastes (Silver Bow Creek). Although long-term monitoring has characterized the general seasonal and flow-related trends in As concentrations in these streams and the pond system used to treat Silver Bow Creek water, little is known about solubility controls and sorption processes that influence diel cycles in As concentrations. Diel (24-h) sampling was conducted in July 2004 and August 2005 at the outlet of the treatment ponds, at two locations along a nearby reconstructed stream channel that diverts tributary water around the ponds, and at Silver Bow Creek 2??km below the ponds. Dissolved As concentration increased up to 51% during the day at most of the stream sites, whereas little or no diel change was displayed at the treatment-pond outlet. The strong cycle in streams is explained by pH- and temperature-dependent sorption of As onto hydrous metal oxides or biofilms on the streambed. Concentrations of dissolved Ca2+ and HCO3- at the stream sites showed a diel temporal pattern opposite to that of As, and geochemical modeling supports the hypothesis that the concentrations of Ca2+ and HCO3- were controlled by precipitation of calcite during the warm afternoon hours when pH rose above 9.0. Nightly increases in dissolved Mn and Fe(II) concentrations were out of phase with concentrations of other divalent cations and are more likely explained by redox phenomena. ?? 2007 Elsevier B.V. All rights reserved.

Seasonal migration to high latitudes results in major reproductive benefits in an insect

PubMed Central

Chapman, Jason W.; Bell, James R.; Burgin, Laura E.; Reynolds, Donald R.; Pettersson, Lars B.; Hill, Jane K.; Bonsall, Michael B.; Thomas, Jeremy A.

2012-01-01

Little is known of the population dynamics of long-range insect migrants, and it has been suggested that the annual journeys of billions of nonhardy insects to exploit temperate zones during summer represent a sink from which future generations seldom return (the “Pied Piper” effect). We combine data from entomological radars and ground-based light traps to show that annual migrations are highly adaptive in the noctuid moth Autographa gamma (silver Y), a major agricultural pest. We estimate that 10–240 million immigrants reach the United Kingdom each spring, but that summer breeding results in a fourfold increase in the abundance of the subsequent generation of adults, all of which emigrate southward in the fall. Trajectory simulations show that 80% of emigrants will reach regions suitable for winter breeding in the Mediterranean Basin, for which our population dynamics model predicts a winter carrying capacity only 20% of that of northern Europe during the summer. We conclude not only that poleward insect migrations in spring result in major population increases, but also that the persistence of such species is dependent on summer breeding in high-latitude regions, which requires a fundamental change in our understanding of insect migration. PMID:22927392

[Poliomyelitis in literature, cinema and television].

PubMed

Collado-Vázquez, Susana; Carrillo, Jesús M; Águila-Maturana, Ana M

2014-10-01

Poliomyelitis is an infectious disease whose initial symptoms are fever, fatigue, headaches, vomiting, a stiff neck and pains in the limbs. In many cases, the sequelae are irreversible paralysis and may result in death if there is bulbar or respiratory compromise. A set of symptoms, called post-polio syndrome, which appears years after the acute infection, are also described. To analyse the way poliomyelitis has been dealt with in literature, cinema and television. Film and television writers and directors have shown an interest in poliomyelitis and have portrayed it in a correct and realistic manner, both in fiction and in biographies or documentary-type works. Nemesis, Silver wattle, Leave her to heaven or The fall are some examples of literary works on the subject. Cinema has also portrayed polio all the way back to silent movies, with titles such as The woman in his house, The Silver Streak, Sister Kenny or The sessions. This disease and its sequelae have also been portrayed on television in series such as Hospital Central, Grey's anatomy, House M.D. or Amar en tiempos revueltos, and in TV films like El asunto, Eleanor and Franklin or Warm Springs. Poliomyelitis has been portrayed in literature, cinema and television in a realistic manner, showing its symptoms, sequelae, and the personal, familial and social impact of this disease.

Adenosine Triphosphate-Encapsulated Liposomes with Plasmonic Nanoparticles for Surface Enhanced Raman Scattering-Based Immunoassays.

PubMed

Pham, Xuan-Hung; Hahm, Eunil; Kim, Tae Han; Kim, Hyung-Mo; Lee, Sang Hun; Lee, Yoon-Sik; Jeong, Dae Hong; Jun, Bong-Hyun

2017-06-23

In this study, we prepared adenosine triphosphate (ATP) encapsulated liposomes, and assessed their applicability for the surface enhanced Raman scattering (SERS)-based assays with gold-silver alloy (Au@Ag)-assembled silica nanoparticles (NPs; SiO₂@Au@Ag). The liposomes were prepared by the thin film hydration method from a mixture of l-α-phosphatidylcholine, cholesterol, and PE-PEG2000 in chloroform; evaporating the solvent, followed by hydration of the resulting thin film with ATP in phosphate-buffered saline (PBS). Upon lysis of the liposome, the SERS intensity of the SiO₂@Au@Ag NPs increased with the logarithm of number of ATP-encapsulated liposomes after lysis in the range of 8 × 10⁶ to 8 × 10 10 . The detection limit of liposome was calculated to be 1.3 × 10 -17 mol. The successful application of ATP-encapsulated liposomes to SiO₂@Au@Ag NPs based SERS analysis has opened a new avenue for Raman label chemical (RCL)-encapsulated liposome-enhanced SERS-based immunoassays.

Spontaneous formation of nanoparticle stripe patterns through dewetting

NASA Astrophysics Data System (ADS)

Huang, Jiaxing; Kim, Franklin; Tao, Andrea R.; Connor, Stephen; Yang, Peidong

2005-12-01

Significant advancement has been made in nanoparticle research, with synthetic techniques extending over a wide range of materials with good control over particle size and shape. A grand challenge is assembling and positioning the nanoparticles in desired locations to construct complex, higher-order functional structures. Controlled positioning of nanoparticles has been achieved in pre-defined templates fabricated by top-down approaches. A self-assembly method, however, is highly desirable because of its simplicity and compatibility with heterogeneous integration processes. Here we report on the spontaneous formation of ordered gold and silver nanoparticle stripe patterns on dewetting a dilute film of polymer-coated nanoparticles floating on a water surface. Well-aligned stripe patterns with tunable orientation, thickness and periodicity at the micrometre scale were obtained by transferring nanoparticles from a floating film onto a substrate in a dip-coating fashion. This facile technique opens up a new avenue for lithography-free patterning of nanoparticle arrays for various applications including, for example, multiplexed surface-enhanced Raman substrates and templated fabrication of higher-order nanostructures.

Mines and Prospects, Idaho Springs District, Clear Creek and Gilpin Counties, Colorado - Descriptions and Maps

USGS Publications Warehouse

Moench, Robert Hadley; Drake, Avery Ala

1966-01-01

The Idaho Springs mining district forms an important segment of the Front Range mineral belt, a northeast-trending zone of coextensive intrusive rocks and hydrothermal ore deposits of early Tertiary age. This belt, which is about 50 miles long, extends from the region just west of Boulder southwestward across the Front Range. From 1859, when placer gold was discovered in Idaho Springs and lode gold in Central City, through 1959, ores valued at about $200 million were shipped from a 50-square-mile area that includes the Idaho Springs and adjacent districts to the north, west, and southwest. The adjacent Central City district, which produced ores valued at more than $100 million, is clearly the most important district in the mineral belt. The Idaho Springs district from 1860 to 1959 produced ores valued at about $65 million, and the districts to the west and southwest produced smaller amounts. Gold has accounted for about 60 percent of the value of the ore, but in some areas silver provides the chief values, and copper, lead, and zinc add value to the ores in most areas. Mining activity in the Idaho Springs and adjacent districts was at its 'heyday' in the late 1800's, it declined sharply after 1914, it was somewhat renewed during the 1930's, and it greatly declined during World War II. In the 1950's uranium prospecting stimulated some mining activity. No uranium was produced, however, and at the close of the decade only one mine--the Bald Eagle--was being worked for its precious- and base-metal ores. In this report, 135 mines and prospects are described. The mines and prospects described are those that were accessible at the time of this study, as well as a few inaccessible properties for which some information was available. Most of the data for the inaccessible or unimportant properties were obtained from Bastin and Hill (1917) and Spurr, Garrey, and Ball (1908). The following list shows, in alphabetical order, the names of about 325 openings of mines and prospects, their coordinate location on the district map (fig. 1), the page of this report on which their description starts, and the number of the illustration, if any, referring to them.

Linking spring phenology with mechanistic models of host movement to predict disease transmission risk

USGS Publications Warehouse

Merkle, Jerod A.; Cross, Paul C.; Scurlock, Brandon M.; Cole, Eric K.; Courtemanch, Alyson B.; Dewey, Sarah R.; Kauffman, Matthew J.

2018-01-01

Disease models typically focus on temporal dynamics of infection, while often neglecting environmental processes that determine host movement. In many systems, however, temporal disease dynamics may be slow compared to the scale at which environmental conditions alter host space-use and accelerate disease transmission.Using a mechanistic movement modelling approach, we made space-use predictions of a mobile host (elk [Cervus Canadensis] carrying the bacterial disease brucellosis) under environmental conditions that change daily and annually (e.g., plant phenology, snow depth), and we used these predictions to infer how spring phenology influences the risk of brucellosis transmission from elk (through aborted foetuses) to livestock in the Greater Yellowstone Ecosystem.Using data from 288 female elk monitored with GPS collars, we fit step selection functions (SSFs) during the spring abortion season and then implemented a master equation approach to translate SSFs into predictions of daily elk distribution for five plausible winter weather scenarios (from a heavy snow, to an extreme winter drought year). We predicted abortion events by combining elk distributions with empirical estimates of daily abortion rates, spatially varying elk seroprevelance and elk population counts.Our results reveal strong spatial variation in disease transmission risk at daily and annual scales that is strongly governed by variation in host movement in response to spring phenology. For example, in comparison with an average snow year, years with early snowmelt are predicted to have 64% of the abortions occurring on feedgrounds shift to occurring on mainly public lands, and to a lesser extent on private lands.Synthesis and applications. Linking mechanistic models of host movement with disease dynamics leads to a novel bridge between movement and disease ecology. Our analysis framework offers new avenues for predicting disease spread, while providing managers tools to proactively mitigate risks posed by mobile disease hosts. More broadly, we demonstrate how mechanistic movement models can provide predictions of ecological conditions that are consistent with climate change but may be more extreme than has been observed historically.

Microwave-assisted green synthesis of silver nanostructures.

PubMed

Nadagouda, Mallikarjuna N; Speth, Thomas F; Varma, Rajender S

2011-07-19

Over the past 25 years, microwave (MW) chemistry has moved from a laboratory curiosity to a well-established synthetic technique used in many academic and industrial laboratories around the world. Although the overwhelming number of MW-assisted applications today are still performed on a laboratory (mL) scale, we expect that this enabling technology may be used on a larger, perhaps even production, scale in conjunction with radio frequency or conventional heating. Microwave chemistry is based on two main principles, the dipolar mechanism and the electrical conductor mechanism. The dipolar mechanism occurs when, under a very high frequency electric field, a polar molecule attempts to follow the field in the same alignment. When this happens, the molecules release enough heat to drive the reaction forward. In the second mechanism, the irradiated sample is an electrical conductor and the charge carriers, ions and electrons, move through the material under the influence of the electric field and lead to polarization within the sample. These induced currents and any electrical resistance will heat the sample. This Account summarizes a microwave (MW)-assisted synthetic approach for producing silver nanostructures. MW heating has received considerable attention as a promising new method for the one-pot synthesis of metallic nanostructures in solutions. Researchers have successfully demonstrated the application of this method in the preparation of silver (Ag), gold (Au), platinum (Pt), and gold-palladium (Au-Pd) nanostructures. MW heating conditions allow not only for the preparation of spherical nanoparticles within a few minutes but also for the formation of single crystalline polygonal plates, sheets, rods, wires, tubes, and dendrites. The morphologies and sizes of the nanostructures can be controlled by changing various experimental parameters, such as the concentration of metallic salt precursors, the surfactant polymers, the chain length of the surfactant polymers, the solvents, and the operation reaction temperature. In general, nanostructures with smaller sizes, narrower size distributions, and a higher degree of crystallization have been obtained more consistently via MW heating than by heating with a conventional oil-bath. The use of microwaves to heat samples is a viable avenue for the greener synthesis of nanomaterials and provides several desirable features such as shorter reaction times, reduced energy consumption, and better product yields.

Microbial glycolipoprotein-capped silver nanoparticles as emerging antibacterial agents against cholera.

PubMed

Gahlawat, Geeta; Shikha, Sristy; Chaddha, Baldev Singh; Chaudhuri, Saumya Ray; Mayilraj, Shanmugam; Choudhury, Anirban Roy

2016-02-01

With the increased number of cholera outbreaks and emergence of multidrug resistance in Vibrio cholerae strains it has become necessary for the scientific community to devise and develop novel therapeutic approaches against cholera. Recent studies have indicated plausibility of therapeutic application of metal nano-materials. Among these, silver nanoparticles (AgNPs) have emerged as a potential antimicrobial agent to combat infectious diseases. At present nanoparticles are mostly produced using physical or chemical techniques which are toxic and hazardous. Thus exploitation of microbial systems could be a green eco-friendly approach for the synthesis of nanoparticles having similar or even better antimicrobial activity and biocompatibility. Hence, it would be worth to explore the possibility of utilization of microbial silver nanoparticles and their conjugates as potential novel therapeutic agent against infectious diseases like cholera. The present study attempted utilization of Ochrobactrum rhizosphaerae for the production of AgNPs and focused on investigating their role as antimicrobial agents against cholera. Later the exopolymer, purified from the culture supernatant, was used for the synthesis of spherical shaped AgNPs of around 10 nm size. Further the exopolymer was characterized as glycolipoprotein (GLP). Antibacterial activity of the novel GLP-AgNPs conjugate was evaluated by minimum inhibitory concentration, XTT reduction assay, scanning electron microscopy (SEM) and growth curve analysis. SEM studies revealed that AgNPs treatment resulted in intracellular contents leakage and cell lysis. The potential of microbially synthesized nanoparticles, as novel therapeutic agents, is still relatively less explored. In fact, the present study first time demonstrated that a glycolipoprotein secreted by the O. rhizosphaerae strain can be exploited for production of AgNPs which can further be employed to treat infectious diseases. Although this type of polymer has been obtained earlier from marine fungi and bacteria, none of these reports have studied the role of this polymer in AgNPs synthesis and its application in cholera therapy. Interestingly, the microbial GLP-capped AgNPs exhibited antibacterial activity against V. cholerae comparable to ciprofloxacin. Thus the present study may open up new avenues for development of novel therapeutic agents for treatment of infectious diseases. Graphical abstract Development of novel therapeutic agents for treatment of cholera.

Synthese et modelisation des proprietes optiques de nanoparticules d'alliage or-argent et leur application en imagerie hyperspectrale

NASA Astrophysics Data System (ADS)

Rioux, David

Metallic nanoparticles (NPs) constitute a research area that has been booming in the recent decades. Among them the plasmonic NPs, which are composed of noble metals such as gold and silver, are the best known and possess extraordinary optical properties. Their ability to strongly absorb and scatter light on a specific band in the visible wavelengths gives them a very intense coloration. Moreover, these structures strongly concentrate the light near their surface upon illumination. These properties can be exploited in a variety of applications from biomedical imaging to detection and even for improving the performance of solar cells. Although gold and silver are the most widely used materials for plasmonic NPs, it has long been known that their alloys have optical properties equally interesting with the added benefit that their color can be controlled by the gold-silver ratio of the alloy. Nevertheless, the gold-silver alloy NPs are not frequently used in different applications. The main reason is probably that the synthesis of these NPs with good size control has not been demonstrated yet. Many applications, including imaging, require NPs which strongly scatter light. Large NPs (50 nm and more) are often required since they scatter light more efficiently. However, the different synthesis methods used until now to produce gold-silver alloy NPs result in sizes smaller than 30 nm or very polydisperse samples, making them unattractive for these applications. The potential to use gold-silver alloy NPs is therefore based on the ability to manufacture them with a sufficiently large diameter and with good size control. It is also important to be able to predict in advance the optical properties of gold-silver alloy nanostructures, to help guide the design of these structures depending on the intended properties. This requires knowledge of the dielectric function of the alloys according to their composition. Although the dielectric function was measured experimentally several times, tabular data are often limited to a few specific compositions and an analytical model would be more interesting. This thesis focuses on the study and modeling of the optical properties of gold-silver alloy NPs, on their synthesis as well as an application example; using these NPs as cell markers for multiplexed scattering imaging. The first part of this thesis deals with a study of the dielectric function of gold-silver alloys in order to develop an analytical model to calculate the dielectric function for an arbitrary composition of the alloy. This model considers the contribution of the free and bound electrons of the metal to the dielectric function. The contribution of free electrons is calculated using the Drude model while the contribution of bound electrons was modeled by studying the shape of the interband transitions from the study of the gold and silver band structures. A parameterized model incorporating these two contributions was developed and composition dependence comes from the evolution of these parameters depending on the composition. The model was validated by comparing the spectra of experimental extinctions alloy NPs with the spectra calculated by the Mie theory using the dielectric functions determined from this model. This model has also been very useful to predict the optical properties and characterize NPs produced by a new synthesis method developed during this PhD project. This method allowed the synthesis of spherical gold-silver alloy NPs with controlled size and composition while maintaining a small size distribution. This technique relies on the combination of two known methods. The first, being used for the synthesis of small alloy NPs, is based on the chemical co-reduction of gold and silver salts in aqueous solution. The second, used for the synthesis of gold or silver NPs of controlled size, is the seed-mediated growth method. Using this new approach, the synthesis sized gold-silver alloy NPs with sizes controlled between 30 and 150 nm has been demonstrated. The synthesized NPs do not have a homogeneous composition with a gold-rich core and a silver-rich surface. This non-homogeneous composition affects the optical properties for the smallest particles (˜ 30 nm) by broadening the plasmon peak and making it asymmetrical, but its effect is considerably less important for larger particles (˜ 60 nm and more) where the measured plasmon peak is similar to that predicted for a homogeneous particle. This new synthesis method thus provides the ability to synthesize high quality alloy NPs for applications requiring controlled size and a precise plasmon peak position. These NPs were used in scattering imaging and their potential as cell markers was studied. It has been shown that the darkfield imaging, a standard technique for scattering imaging, is not optimal for the observation of NPs on cells because of the strong scattering signal of the latter. An alternative approach based on the detection of the backscattering of the NPs was proposed. This approach provides better contrast for the NPs as their backscatter signal is much stronger than that of the cells. In this thesis, a semi-quantitative study of the contrast of the NPs relative to cells explain why the backscattering approach is more promising than the darkfield imaging for cell labeling. Overall, this thesis covers many aspects of the gold-silver alloy NPs, either theoretical understanding of the optical properties, the development of the synthesis method and an application example. It also paves the way for many other avenues of research in the optimization of the method of synthesis of the particles as well as in their use in imaging applications and others.

Handbook of Inviscid Sphere-Cone Flow Fields and Pressure Distributions. Volume 2

DTIC Science & Technology

1975-12-01

r, ý I A ror) rv N Ay(T rfrFvTC. TP NTS I YrP/L VP/C YVfP/LV PN/Q0 *5c07 3 r 47 A ,Ir )6A S4 * ec; 445 AL?~ .R?; * 179 p 0 In -󈧻 C; C 3 c* t. 31 *i77...distribuion unlimited 3publJ NAVAL SURFACE WEAPONS CENTER WHITE OAK, SILVER SPRING, MARYLAND 20910 Ii REPORT DOCUMENTATION PAGE HAJNICIN ൒" 1~ A C t...SSION.. h I tFC 0 Fi~(0 OF INVI𔃿C1 rirr .g!n- TC< -P rF.FA"T,. JMFSSURF rTs’TR!PIP10N\\e- _____________ T~l t 6S PEROft..𔃿OlR5 EOT .I A CONTRPA:- r :; A

Assessing the ability of operational snow models to predict snowmelt runoff extremes (Invited)

NASA Astrophysics Data System (ADS)

Wood, A. W.; Restrepo, P. J.; Clark, M. P.

2013-12-01

In the western US, the snow accumulation and melt cycle of winter and spring plays a critical role in the region's water management strategies. Consequently, the ability to predict snowmelt runoff at time scales from days to seasons is a key input for decisions in reservoir management, whether for avoiding flood hazards or supporting environmental flows through the scheduling of releases in spring, or for allocating releases for multi-state water distribution in dry seasons of year (using reservoir systems to provide an invaluable buffer for many sectors against drought). Runoff forecasts thus have important benefits at both wet and dry extremes of the climatological spectrum. The importance of the prediction of the snow cycle motivates an assessment of the strengths and weaknesses of the US's central operational snow model, SNOW17, in contrast to process-modeling alternatives, as they relate to simulating observed snowmelt variability and extremes. To this end, we use a flexible modeling approach that enables an investigation of different choices in model structure, including model physics, parameterization and degree of spatiotemporal discretization. We draw from examples of recent extreme events in western US watersheds and an overall assessment of retrospective model performance to identify fruitful avenues for advancing the modeling basis for the operational prediction of snow-related runoff extremes.

Space Projects and Research by Kids (SPARK): A Web Based Research Journal for Middle School Students

NASA Astrophysics Data System (ADS)

Limaye, S. S.; Pertzborn, R. A.

1999-05-01

Project SPARK is designed to facilitate opportunities for upper elementary and middle school students to develop the necessary skills to conduct investigations that focus on the subjects of astronomy, space exploration, and earth remote sensing. This program actively engages students in conducting their own research project to acquire increased understanding and content knowledge in the space sciences. While the development of scientific inquiry skills and content literacy is the primary focus, students also enhance their critical thinking, analytical, technological and communications skills. As in the professional science community, the web based SPARK Journal presents an avenue for students to effectively communicate the results of their investigations and work to classmates as well as the "global learning community" via the world wide web. Educational outreach staff at the Sapce Science and Engineering Center have developed active partnerships with teachers and schools throughout Wisconsin to facilitate the development of standards based curriculum and research projects focusing on current topics in the space sciences. Student research projects and activities arising from these initiatives were submitted in the Spring and Fall of 1998 for inclusion in SPARK, Volume 1. The second volume of SPARK will be published in Spring, 1999. Support for the development of this journal was provided by the NASA/IDEAS Program.

National K-12 Educator Conference; "Earth Then, Earth Now: Our Changing Climate" (July 23-24, 2008)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flammer, Karen; O'Shaughnessy, Tam

With the support of the Department of Energy, the National Science Teachers Association and the National Oceanic and Atmospheric Administration, Imaginary Lines Inc. (dba Sally Ride Science) delivered a highly successful 2-day conference to 165 K-12 educators on climate change. The event took place on July 23rd and 24th, 2008 at the NOAA facility in Silver Spring, MD. The conference celebrated the 25th anniversary of Dr. Sally Ride’s first flight into space in 1983 and examined how our understanding of Earth has changed in those 25 years. One the first day of the conference, participants heard a keynote talk deliveredmore » by Dr. Sally Ride, followed by presentations by well-known climate change scientists: Dr. Richard Somerville, Dr. Inez Fung and Dr. Susan Solomon. These sessions were concurrently webcast and made available to educators who were unable to attend the conference. On the second day of the conference, participants attended breakout sessions where they performed climate change activities (e.g. “Neato Albedo!”, “Greenhouse in a Bottle”, “Shell-Shocked”) that they could take back to their classrooms. Additional break-out sessions on using remote sensing images to illustrate climate change effects on Earth’s surface and how to address the climate change debate, were also offered. During lunch, participants attended an Educator Street Fair and had the opportunity to interact with representatives from NOAA, NASA, the EPA, NEEF and the JASON project. A follow-up evaluation survey was administered to all conference attendees immediately following the conference to evaluate its effectiveness. The results of this survey were overwhelmingly positive. The conference materials: presentation Power Points, workshop handouts and activities were available for teachers to download after the conference from the Sally Ride Science website. In summary, the approximately $55K support for the Department of Energy was used to help plan, deliver and evaluate the “Earth Then, Earth Now: Our Changing Climate”, conference which took place on July 23rd and 24th, 2008 at the NOAA facility in Silver Spring, MD.« less

Optimization of silver-dielectric-silver nanoshell for sensing applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shirzaditabar, Farzad; Saliminasab, Maryam

2013-08-15

In this paper, resonance light scattering (RLS) properties of a silver-dielectric-silver nanoshell, based on quasi-static approach and plasmon hybridization theory, are investigated. Scattering spectrum of silver-dielectric-silver nanoshell has two intense and clearly separated RLS peaks and provides a potential for biosensing based on surface plasmon resonance and surface-enhanced Raman scattering. The two RLS peaks in silver-dielectric-silver nanoshell are optimized by tuning the geometrical dimensions. In addition, the optimal geometry is discussed to obtain the high sensitivity of silver-dielectric-silver nanoshell. As the silver core radius increases, the sensitivity of silver-dielectric-silver nanoshell decreases whereas increasing the middle dielectric thickness increases the sensitivitymore » of silver-dielectric-silver nanoshell.« less

Rapid biosynthesis and characterization of silver nanoparticles: an assessment of antibacterial and antimycotic activity

NASA Astrophysics Data System (ADS)

Kanawaria, Sajjan Kumar; Sankhla, Aryan; Jatav, Pradeep Kumar; Yadav, Raghvendra Singh; Verma, Kumar Sambhav; Velraj, Parthiban; Kachhwaha, Sumita; Kothari, Shanker Lal

2018-04-01

Bioassisted synthesis provides a facile, convenient, and promising approach to produce many inorganic nanostructures. Herein, we report a rapid biosynthesis of silver nanoparticles (AgNPs) using Thuja occidentalis (L.) leaf extract with an emphasis on their antibacterial and antimycotic activity. Interestingly, the synthesis of AgNPs was completed in a short duration of 35-40 min. The electron micrographs showed AgNPs with particles < 30 nm in size. A diffusive absorption band around 430 nm confirmed the polydispersive nature of biosynthesized AgNPs. An additional absorption peak at 256 nm suggested the presence of biomolecules in the reaction mixture in addition to AgNPs. The different bands corresponding to ring compounds, amines, and carbonyl groups in the FT-IR spectra of biosynthesized AgNPs confirmed the presence of terpenes and terpenoids on AgNP surface post-reduction. The encapsulation and stabilization of AgNPs by organic layer was visible from the TEM images. Thus, these organic compounds present in the extract were responsible for first the reduction of precursor salts into AgNPs and second to drape around the particles preventing agglomeration. The AgNPs were effective against strains of Escherichia coli, Pseudomonas putida, and Bacillus subtilis. An AgNP solution with 30 µg/ml concentration arrested the growth of bacterial strains making a zone of inhibition > 15 mm. The antimycotic activity against Aspergillus niger, Fusarium spp., and Alternaria alternata species increased monotonically with nanoparticle concentration in the growth media. A 10 ppm solution of AgNP was detrimental to fungal growth. Thus, the technique provides an avenue to synthesize antibiotic AgNPs without use of other external agents.

Intrapopulation Genotypic Variation of Foliar Secondary Chemistry during Leaf Senescence and Litter Decomposition in Silver Birch (Betula pendula)

PubMed Central

Paaso, Ulla; Keski-Saari, Sarita; Keinänen, Markku; Karvinen, Heini; Silfver, Tarja; Rousi, Matti; Mikola, Juha

2017-01-01

Abundant secondary metabolites, such as condensed tannins, and their interpopulation genotypic variation can remain through plant leaf senescence and affect litter decomposition. Whether the intrapopulation genotypic variation of a more diverse assortment of secondary metabolites equally persists through leaf senescence and litter decomposition is not well understood. We analyzed concentrations of intracellular phenolics, epicuticular flavonoid aglycones, epicuticular triterpenoids, condensed tannins, and lignin in green leaves, senescent leaves and partly decomposed litter of silver birch, Betula pendula. Broad-sense heritability (H2) and coefficient of genotypic variation (CVG) were estimated for metabolites in senescent leaves and litter using 19 genotypes selected from a B. pendula population in southern Finland. We found that most of the secondary metabolites remained through senescence and decomposition and that their persistence was related to their chemical properties. Intrapopulation H2 and CVG for intracellular phenolics, epicuticular flavonoid aglycones and condensed tannins were high and remarkably, increased from senescent leaves to decomposed litter. The rank of genotypes in metabolite concentrations was persistent through litter decomposition. Lignin was an exception, however, with a diminishing genotypic variation during decomposition, and the concentrations of lignin and condensed tannins had a negative genotypic correlation in the senescent leaves. Our results show that secondary metabolites and their intrapopulation genotypic variation can for the most part remain through leaf senescence and early decomposition, which is a prerequisite for initial litter quality to predict variation in litter decomposition rates. Persistent genotypic variation also opens an avenue for selection to impact litter decomposition in B. pendula populations through acting on their green foliage secondary chemistry. The negative genotypic correlations and diminishing heritability of lignin concentrations may, however, counteract this process. PMID:28694813

Silver nanoparticle-induced hemoglobin decrease involves alteration of histone 3 methylation status.

PubMed

Qian, Yi; Zhang, Jie; Hu, Qinglin; Xu, Ming; Chen, Yue; Hu, Guoqing; Zhao, Meirong; Liu, Sijin

2015-11-01

Silver nanoparticles (nanosilver, AgNPs) have been shown to induce toxicity in vitro and in vivo; however, the molecular bases underlying the detrimental effects have not been thoroughly understood. Although there are numerous studies on its genotoxicity, only a few studies have investigated the epigenetic changes, even less on the changes of histone modifications by AgNPs. In the current study, we probed the AgNP-induced alterations to histone methylation that could be responsible for globin reduction in erythroid cells. AgNP treatment caused a significant reduction of global methylation level for histone 3 (H3) in erythroid MEL cells at sublethal concentrations, devoid of oxidative stress. The ChIP-PCR analyses demonstrated that methylation of H3 at lysine (Lys) 4 (H3K4) and Lys 79 (H3K79) on the β-globin locus was greatly reduced. The reduction in methylation could be attributed to decreased histone methyltransferase DOT-1L and MLL levels as well as the direct binding between AgNPs to H3/H4 that provide steric hindrance to prevent methylation as predicted by the all-atom molecular dynamics simulations. This direct interaction was further proved by AgNP-mediated pull-down assay and immunoprecipitation assay. These changes, together with decreased RNA polymerase II activity and chromatin binding at this locus, resulted in decreased hemoglobin production. By contrast, Ag ion-treated cells showed no alterations in histone methylation level. Taken together, these results showed a novel finding in which AgNPs could alter the methylation status of histone. Our study therefore opens a new avenue to study the biological effects of AgNPs at sublethal concentrations from the perspective of epigenetic mechanisms. Copyright © 2015 Elsevier Ltd. All rights reserved.

Intrapopulation Genotypic Variation of Foliar Secondary Chemistry during Leaf Senescence and Litter Decomposition in Silver Birch (Betula pendula).

PubMed

Paaso, Ulla; Keski-Saari, Sarita; Keinänen, Markku; Karvinen, Heini; Silfver, Tarja; Rousi, Matti; Mikola, Juha

2017-01-01

Abundant secondary metabolites, such as condensed tannins, and their interpopulation genotypic variation can remain through plant leaf senescence and affect litter decomposition. Whether the intrapopulation genotypic variation of a more diverse assortment of secondary metabolites equally persists through leaf senescence and litter decomposition is not well understood. We analyzed concentrations of intracellular phenolics, epicuticular flavonoid aglycones, epicuticular triterpenoids, condensed tannins, and lignin in green leaves, senescent leaves and partly decomposed litter of silver birch, Betula pendula . Broad-sense heritability ( H 2 ) and coefficient of genotypic variation ( CV G ) were estimated for metabolites in senescent leaves and litter using 19 genotypes selected from a B. pendula population in southern Finland. We found that most of the secondary metabolites remained through senescence and decomposition and that their persistence was related to their chemical properties. Intrapopulation H 2 and CV G for intracellular phenolics, epicuticular flavonoid aglycones and condensed tannins were high and remarkably, increased from senescent leaves to decomposed litter. The rank of genotypes in metabolite concentrations was persistent through litter decomposition. Lignin was an exception, however, with a diminishing genotypic variation during decomposition, and the concentrations of lignin and condensed tannins had a negative genotypic correlation in the senescent leaves. Our results show that secondary metabolites and their intrapopulation genotypic variation can for the most part remain through leaf senescence and early decomposition, which is a prerequisite for initial litter quality to predict variation in litter decomposition rates. Persistent genotypic variation also opens an avenue for selection to impact litter decomposition in B. pendula populations through acting on their green foliage secondary chemistry. The negative genotypic correlations and diminishing heritability of lignin concentrations may, however, counteract this process.

ISS-CREAM Thermal and Fluid System Design and Analysis

NASA Technical Reports Server (NTRS)

Thorpe, Rosemary S.

2015-01-01

Thermal and Fluids Analysis Workshop (TFAWS), Silver Spring MD NCTS 21070-15. The ISS-CREAM (Cosmic Ray Energetics And Mass for the International Space Station) payload is being developed by an international team and will provide significant cosmic ray characterization over a long time frame. Cold fluid provided by the ISS Exposed Facility (EF) is the primary means of cooling for 5 science instruments and over 7 electronics boxes. Thermal fluid integrated design and analysis was performed for CREAM using a Thermal Desktop model. This presentation will provide some specific design and modeling examples from the fluid cooling system, complex SCD (Silicon Charge Detector) and calorimeter hardware, and integrated payload and ISS level modeling. Features of Thermal Desktop such as CAD simplification, meshing of complex hardware, External References (Xrefs), and FloCAD modeling will be discussed.

Lessons Learned During the Refurbishment and Testing of an Observatory After Long-Term Storage

NASA Technical Reports Server (NTRS)

Hawk, John; Peabody, Sharon; Stavely, Richard

2015-01-01

Thermal Fluids Analysis Workshop (TFAWS) 2015, Silver Spring, MD NCTS 21070-15. This paper addresses the lessons learned during the refurbishment and testing of the thermal control system for a spacecraft which was placed into long-term storage. The DSCOVR (Deep Space Climate Observatory) Observatory (formerly known as Triana) was originally scheduled to launch on the Space Shuttle in 2002. With the Triana spacecraft nearly complete, the mission was canceled and the satellite was abruptly put into storage in 2001. In 2008 the observatory was removed from storage to begin refurbishment and testing. Problems arose associated with hardware that was not currently manufactured, coatings degradation, and a significant lack of documentation. Also addressed is the conversion of the thermal and geometric math models for use with updated thermal analysis software tools.

Skin reflectance as a non-lethal measure of smoltification for juvenile salmonids

USGS Publications Warehouse

Haner, Philip V.; Faler, Joyce C.; Schrock, Robin M.; Rondorf, Dennis W.; Maule, Alec G.

1995-01-01

Our efforts to find nonlethal methods of assessing the parr-smoll transformation of juvenile steelhead Oncorhynchus mykiss and spring and fall chinook salmon O. tshawytscha led to the development of a video system for quantitatively measuring skin silvering using skin reflectance. Gill Na'.K'-ATPase activity, skin guanine concentration, and skin reflectance were recorded from groups of fish marked with freeze brands at hatcheries and downstream sample sites in the Columbia River basin. Skin reflectance of migrants was significantly higher than that of fish before release; nonmigrants (released fish that did not migrate) had significantly lower skin reflectance than migrants from the same groups. Skin reflectance was significantly correlated with gill ATPasc activity and skin guanine concentration. Skin reflectance increased during the parrsmolt transformation and could be used as a nonlethal indicator of smoltification.

IGS 1996 Analysis Center Workshop

NASA Technical Reports Server (NTRS)

Neilan, R. E. (Editor); VanScoy, P. A. (Editor); Zumberge, J. F. (Editor)

1996-01-01

Components of the IGS[International GPS (Global Positioning System) Service for geodynamics], have operated a GPS tracking system for several years. The network now contains more than 100 stations and has produced a combined GPS ephemeris that has become the standard for geodesists and geophysicists worldwide. IGS data and products are freely available to all thanks to the cooperation and participation of all the IGS members. The IGS has initiated development of several new products, and technical issues permitting greater accuracy of IGS products have been identified. The IGS convened a workshop on March 1996 in Silver Spring, Maryland, USA, to coordinate these developments and to examine technical problems and solutions. The following topics were addressed: orbit/clock combination; Earth orientation; antenna calibration; SINEX and densification of the International Terrestrial Reference Frame (ITRF) using the GPS; receiver standards and performance; and atmospheric topics.

Official STS-67 preflight crew portrait

NASA Image and Video Library

1994-12-01

STS067-S-002 (December 1994) --- Five NASA astronauts and two payload specialists from the private sector have been named to fly aboard the Space Shuttle Endeavour for the STS-67/ASTRO-2 mission, scheduled for March 1995. In front are astronauts (left to right) Stephen S. Oswald, mission commander; Tamara E. Jernigan, payload commander; and William G. Gregory, pilot. In the back are (left to right) Ronald A. Parise, payload specialist; astronauts Wendy B. Lawrence, and John M. Grunsfeld, both mission specialists; and Samuel T. Durrance, payload specialist. Dr. Durrance is a research scientist in the Department of Physics and Astronomy at Johns Hopkins University, Baltimore, Maryland. Dr. Parise is a senior scientist in the Space Observatories Department, Computer Sciences Corporation, Silver Spring, Maryland. Both payload specialist's flew aboard the Space Shuttle Columbia for the STS-35/ASTRO-1 mission in December 1990.

Twilight far-red treatment advances leaf bud burst of silver birch (Betula pendula).

PubMed

Linkosalo, Tapio; Lechowicz, Martin J

2006-10-01

Bud development of boreal trees in spring, once initiated, is driven by ambient air temperature, but the mechanism triggering bud development remains unclear. We determined if some aspect of the diurnal or seasonal light regime influences initiation of bud burst once the chilling requirement is met. We grew 3-year-old birch plantlets cloned from a mature tree of boreal origin in light conditions realistically simulating the lengthening days of spring at 60 degrees N. To emulate the reduction in red to far-red light (R:FR) ratio between daylight and twilight, one group of plantlets was subjected to reduced R:FR ratio in the morning and evening in addition to progressively lengthening days, whereas the other group was subjected to the same R:FR ratio throughout the day. The reduced R:FR ratio of twilight advanced bud burst by 4 days compared with the reference group (P = 0.04). To assess the interplay between the fulfillment of the chilling requirement and the subsequent response to warming, we fitted a thermal time model to the data with separate parameterizations for the starting dates of heat sum accumulation in each treatment. Least-squares fitting suggested that bud development started in light regimes corresponding to late March, almost two months after the chilling requirement for dormancy release was satisfied. Therefore, shortening night length or increasing day length, or both, appears to be the cue enabling bud development in spring, with twilight quality having an effect on the photoperiodic response. If twilight alone were the cue, the difference in bud burst dates between the experimental groups would have been greater than 4 days. The result gives experimental support for the use of thermal-time models in phenological modeling.

Overview taken from the corner of Avenue E (Russell Avenue) ...

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

Overview taken from the corner of Avenue E (Russell Avenue) and Central Avenue. Facility 167 in background. View facing northwest - U.S. Naval Base, Pearl Harbor, Administration Annex, Near Russell Avenue (previously Avenue E), between of Facility Nos. 1C & 1E , Pearl City, Honolulu County, HI

Extraordinarily high conductivity of flexible adhesive films by hybrids of silver nanoparticle-nanowires

NASA Astrophysics Data System (ADS)

Muhammed Ajmal, C.; Mol Menamparambath, Mini; Ryeol Choi, Hyouk; Baik, Seunghyun

2016-06-01

Highly conductive flexible adhesive (CFA) film was developed using micro-sized silver flakes (primary fillers), hybrids of silver nanoparticle-nanowires (secondary fillers) and nitrile butadiene rubber. The hybrids of silver nanoparticle-nanowires were synthesized by decorating silver nanowires with silver nanoparticle clusters using bifunctional cysteamine as a linker. The dispersion in ethanol was excellent for several months. Silver nanowires constructed electrical networks between the micro-scale silver flakes. The low-temperature surface sintering of silver nanoparticles enabled effective joining of silver nanowires to silver flakes. The hybrids of silver nanoparticle-nanowires provided a greater maximum conductivity (54 390 S cm-1) than pure silver nanowires, pure multiwalled carbon nanotubes, and multiwalled carbon nanotubes decorated with silver nanoparticles in nitrile butadiene rubber matrix. The resistance change was smallest upon bending when the hybrids of silver nanoparticle-nanowires were employed. The adhesion of the film on polyethylene terephthalate substrate was excellent. Light emitting diodes were successfully wired to the CFA circuit patterned by the screen printing method for application demonstration.

Photochemical Study of Silver Nanoparticles Formed from the Reduction of Silver Ions by Humic Acid

NASA Astrophysics Data System (ADS)

Leslie, Renee M.

This study focuses on the ability of silver ions and humic acid to form silver nanoparticles in the presence of UV and visible light. Silver nanoparticles have a number of industrial applications due primarily to their antimicrobial properties, but these properties pose an environmental threat. Silver nanoparticles can directly disrupt sensitive ecosystems by harming bacteria. Consumption of silver nanoparticles results in silver ions and silver nanoparticles entering waterways; the presence of silver ions raises the question of whether nanoparticles can reform in environmental waters. As our data show, silver nanoparticles can form from the reduction of silver ions by humic acid after irradiation with UV and visible light. In order to better understand the mechanism of these naturally synthesized silver nanoparticles, we investigated the effects of reactant concentration, experimental conditions and presence of ions/reactive species. We monitored silver nanoparticle growth with UV-visible spectroscopy. The evolution in time of nanoparticle size was monitored by dynamic light scattering (DLS).

Noble metal superparticles and methods of preparation thereof

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Yugang; Hu, Yongxing

A method comprises heating an aqueous solution of colloidal silver particles. A soluble noble metal halide salt is added to the aqueous solution which undergoes a redox reaction on a surface of the silver particles to form noble metal/silver halide SPs, noble metal halide/silver halide SPs or noble metal oxide/silver halide SPs on the surface of the silver particles. The heat is maintained for a predetermined time to consume the silver particles and release the noble metal/silver halide SPs, the noble metal halide/silver halide SPs or the noble metal oxide/silver halide SPs into the aqueous solution. The aqueous solution ismore » cooled. The noble metal/silver halide SPs, the noble metal halide/silver halide SPs or noble metal oxide/silver halide SPs are separated from the aqueous solution. The method optionally includes adding a soluble halide salt to the aqueous solution.« less

Effect of nano silver and silver nitrate on seed yield of (Ocimum basilicum L.)

PubMed Central

2014-01-01

Background The aim of this study was to evaluate the effect of nano silver and silver nitrate on yield of seed in basil plant. The study was carried out in a randomized block design with three replications. Results Four levels of either silver nitrate (0, 100, 200 and 300 ppm) or nano silver (0, 20, 40, and 60 ppm) were sprayed on basil plant at seed growth stage. The results showed that there was no significant difference between 100 ppm of silver nitrate and 60 ppm concentration of nano silver on the shoot silver concentration. However, increasing the concentration of silver nitrate from 100 to 300 ppm caused a decrease in seed yield. In contrast, a raise in the concentration of nano silver from 20 to 60 ppm has led to an improvement in the seed yield. Additionally, the lowest amount of seed yield was found with control plants. Conclusions Finally, with increasing level of silver nitrate, the polyphenol compound content was raised but the enhancing level of nano silver resulting in the reduction of these components. In conclusion, nano silver can be used instead of other compounds of silver. PMID:25383311

The Empirical Formula of Silver Sulfide: An Experiment for Introductory Chemistry

ERIC Educational Resources Information Center

Trujillo, Carlos Alexander

2007-01-01

An experiment is described that allows students to experimentally determine an empirical formula for silver sulfide. At elevated temperatures, silver sulfide reacts in air to form silver, silver sulfate, and sulfur dioxide. At higher temperatures (960 [degree]C) silver sulfate decomposes to produce metallic silver. (Contains 1 figure and 1 table.)

Factors influencing the preparation of silver-coated glass frit with polyvinyl-pyrrolidone

NASA Astrophysics Data System (ADS)

Xiang, Feng; Gan, Weiping

2018-01-01

In this work, a new electroless silver plating method for the synthesis of silver-coated glass frit composite powders with good morphology has been proposed and the polyvinyl-pyrrolidone (PVP) was used the activating agent. It was found that the weight ratio of PVP to glass frit affected the distribution and number of silver nanoparticles. Moreover, the loading capacity of the glass frit, the pH value and reaction temperature could influence the size of the silver nanoparticles and morphology of silver on the surface of glass frit. The as-prepared silver-coated glass frit was used to prepare a silver paste using an optimized process to form silver nanoparticles with uniform size and high density. The silver paste with silver-coated glass frit increased the photovoltaic conversion efficiency of silicon solar cells by 0.271% compared with the silver paste prepared with pure glass frit. The silver nanoparticles can promoted the precipitation of Ag crystallites on the silicon wafer. Therefore, the silver-coated glass frit can further optimize and enhance the electrical performance of solar cells.

Wood anatomy and carbon-isotope discrimination support long-term hydraulic deterioration as a major cause of drought-induced dieback.

PubMed

Pellizzari, Elena; Camarero, J Julio; Gazol, Antonio; Sangüesa-Barreda, Gabriel; Carrer, Marco

2016-06-01

Hydraulic impairment due to xylem embolism and carbon starvation are the two proposed mechanisms explaining drought-induced forest dieback and tree death. Here, we evaluate the relative role played by these two mechanisms in the long-term by quantifying wood-anatomical traits (tracheid size and area of parenchyma rays) and estimating the intrinsic water-use efficiency (iWUE) from carbon isotopic discrimination. We selected silver fir and Scots pine stands in NE Spain with ongoing dieback processes and compared trees showing contrasting vigour (declining vs nondeclining trees). In both species earlywood tracheids in declining trees showed smaller lumen area with thicker cell wall, inducing a lower theoretical hydraulic conductivity. Parenchyma ray area was similar between the two vigour classes. Wet spring and summer conditions promoted the formation of larger lumen areas, particularly in the case of nondeclining trees. Declining silver firs presented a lower iWUE than conspecific nondeclining trees, but the reverse pattern was observed in Scots pine. The described patterns in wood anatomical traits and iWUE are coherent with a long-lasting deterioration of the hydraulic system in declining trees prior to their dieback. Retrospective quantifications of lumen area permit to forecast dieback in declining trees 2-5 decades before growth decline started. Wood anatomical traits provide a robust tool to reconstruct the long-term capacity of trees to withstand drought-induced dieback. © 2016 John Wiley & Sons Ltd.

Plasmon-mediated binding forces on gold or silver homodimer and heterodimer

NASA Astrophysics Data System (ADS)

Liaw, Jiunn-Woei; Kuo, Ting-Yu; Kuo, Mao-Kuen

2016-02-01

This study theoretically investigates plasmon-mediated optical binding forces, which are exerted on metal homo or heterodimers, induced by the normal illumination of a linearly polarized plane wave or Gaussian beam. Using the multiple multipole method, we analyzed the optical force in terms of Maxwell's stress tensor for various interparticle distance at some specific wavelengths. Numerical results show that for a given wavelength there are several stable equilibrium distances between two nanoparticles (NPs) of a homodimer, which are slightly shorter than some integer multiples of the wavelength in medium, such that metal dimer acts as bonded together. At these specific interparticle distances, the optical force between dimer is null and serves a restoring force, which is repulsive and attractive, respectively, as the two NPs are moving closer to and away from each other. The spring constant of the restoring force at the first stable equilibrium is always the largest, indicating that the first stable equilibrium distance is the most stable one. Moreover, the central line (orientation) of a dimer tends to be perpendicular to the polarization of light. For the cases of heterodimers, the phenomenon of stable equilibrium interparticle distance still exists, except there is an extra net photophoretic force drifting the heterodimer as one. Moreover, gradient force provided by a Gaussian beam may reduce the stability of these equilibriums, so larger NPs are preferred to stabilize a dimer under illumination of Gaussian beam. The finding may pave the way for using optical manipulation on the gold or silver colloidal self-assembly.

Method for the recovery of silver from silver zeolite

DOEpatents

Reimann, G.A.

1985-03-05

High purity silver is recovered from silver exchanged zeolite used to capture radioactive iodine from nuclear reactor and nuclear fuel reprocessing environments. The silver exchanged zeolite is heated with slag formers to melt and fluidize the zeolite and release the silver, the radioactivity removing with the slag. The silver containing metallic impurities is remelted and treated with oxygen and a flux to remove the metal impurities. About 98% of the silver in the silver exchanged zeolite having a purity of 99% or better is recoverable by the method.

Method for the recovery of silver from silver zeolite

DOEpatents

Reimann, George A.

1986-01-01

High purity silver is recovered from silver exchanged zeolite used to capture radioactive iodine from nuclear reactor and nuclear fuel reprocessing environments. The silver exchanged zeolite is heated with slag formers to melt and fluidize the zeolite and release the silver, the radioactivity removing with the slag. The silver containing metallic impurities is remelted and treated with oxygen and a flux to remove the metal impurities. About 98% of the silver in the silver exchanged zeolite having a purity of 99% or better is recoverable by the method.

Glass frits coated with silver nanoparticles for silicon solar cells

NASA Astrophysics Data System (ADS)

Li, Yingfen; Gan, Weiping; Zhou, Jian; Li, Biyuan

2015-06-01

Glass frits coated with silver nanoparticles were prepared by electroless plating. Gum Arabic (GA) was used as the activating agent of glass frits without the assistance of stannous chloride or palladium chloride. The silver-coated glass frits prepared with different GA dosages were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and thermogravimetric analysis (TGA). The characterization results indicated that silver-coated glass frits had the structures of both glass and silver. Spherical silver nanoparticles were distributed on the glass frits evenly. The density and particle size of silver nanoparticles on the glass frits can be controlled by adjusting the GA dosage. The silver-coated glass frits were applied to silver pastes to act as both the densification promoter and silver crystallite formation aid in the silver electrodes. The prepared silver-coated glass frits can improve the photovoltaic performances of solar cells.

Silver(II) Oxide or Silver(I,III) Oxide?

ERIC Educational Resources Information Center

Tudela, David

2008-01-01

The often called silver peroxide and silver(II) oxide, AgO or Ag[subscript 2]O[subscript 2], is actually a mixed oxidation state silver(I,III) oxide. A thermochemical cycle, with lattice energies calculated within the "volume-based" thermodynamic approach, explain why the silver(I,III) oxide is more stable than the hypothetical silver(II) oxide.…

Mercury from mineral deposits and potential environmental impact

USGS Publications Warehouse

Rytuba, J.J.

2003-01-01

Mercury deposits are globally distributed in 26 mercury mineral belts. Three types of mercury deposits occur in these belts: silica-carbonate, hot-spring, and Almaden. Mercury is also produced as a by-product from several types of gold-silver and massive sulfide deposits, which account for 5% of the world's production. Other types of mineral deposits can be enriched in mercury and mercury phases present are dependent on deposit type. During processing of mercury ores, secondary mercury phases form and accumulate in mine wastes. These phases are more soluble than cinnabar, the primary ore mineral, and cause mercury deposits to impact the environment more so than other types of ore deposits enriched in mercury. Release and transport of mercury from mine wastes occur primarily as mercury-enriched particles and colloids. Production from mercury deposits has decreased because of environmental concerns, but by-product production from other mercury-enriched mineral deposits remains important.

Process for making silver metal filaments

DOEpatents

Bamberger, Carlos E.

1997-01-01

A process for making silver metal particles from silver salt particles having the same morphology. Precursor silver salt particles selected from the group consisting of silver acetate and silver sulfide having a selected morphology are contained in a reactor vessel having means for supporting the particles in an air suspension to prevent the agglomeration of the particles. Air is flowed through the reactor vessel at a flow rate sufficient to suspend the particles in the reactor vessel. The suspended precursor silver salt particles are heated to a processing temperature and at a heating rate below which the physical deterioration of the suspended precursor silver salt particles takes place. The suspended precursor silver salt particles are maintained at the processing temperature for a period of time sufficient to convert the particles into silver metal particles having the same morphology as the precursor silver salt particles.

Room temperature synthesis of silver nanowires from tabular silver bromide crystals in the presence of gelatin

NASA Astrophysics Data System (ADS)

Liu, Suwen; Wehmschulte, Rudolf J.; Lian, Guoda; Burba, Christopher M.

2006-03-01

Long silver nanowires were synthesized at room temperature by a simple and fast process derived from the development of photographic films. A film consisting of an emulsion of tabular silver bromide grains in gelatin was treated with a photographic developer (4-(methylamino)phenol sulfate (metol), citric acid) in the presence of additional aqueous silver nitrate. The silver nanowires have lengths of more than 50 μm, some even more than 100 μm, and average diameters of about 80 nm. Approximately, 70% of the metallic silver formed in the reduction consists of silver nanowires. Selected area electron diffraction (SAED) results indicate that the silver nanowires grow along the [111] direction. It was found that the presence of gelatin, tabular silver bromide crystals and silver ions in solution are essential for the formation of the silver nanowires. The nanowires appear to originate from the edges of the silver bromide crystals. They were characterized by transmission electron microscopy (TEM), SAED, scanning electron microscopy (SEM), and powder X-ray diffraction (XRD).

Antibacterial activity and toxicity of silver - nanosilver versus ionic silver

NASA Astrophysics Data System (ADS)

Kvitek, L.; Panacek, A.; Prucek, R.; Soukupova, J.; Vanickova, M.; Kolar, M.; Zboril, R.

2011-07-01

The in vitro study of antibacterial activity of silver nanoparticles (NPs), prepared via modified Tollens process, revealed high antibacterial activity even at very low concentrations around several units of mg/L. These concentrations are comparable with concentrations of ionic silver revealing same antibacterial effect. However, such low concentrations of silver NPs did not show acute cytotoxicity to mammalian cells - this occurs at concentrations higher than 60 mg/L of silver, while the cytotoxic level of ionic silver is much more lower (approx. 1 mg/L). Moreover, the silver NPs exhibit lower acute ecotoxicity against the eukaryotic organisms such as Paramecium caudatum, Monoraphidium sp. and D. melanogaster. The silver NPs are toxic to these organisms at the concentrations higher than 30 mg/L of silver. On contrary, ionic silver retains its cytoxicity and ecotoxicity even at the concentration equal to 1 mg/L. The performed experiments demonstrate significantly lower toxicity of silver NPs against the eukaryotic organisms than against the prokaryotic organisms.

Separation of silver ions and starch modified silver nanoparticles using high performance liquid chromatography with ultraviolet and inductively coupled mass spectrometric detection

NASA Astrophysics Data System (ADS)

Hanley, Traci A.; Saadawi, Ryan; Zhang, Peng; Caruso, Joseph A.; Landero-Figueroa, Julio

2014-10-01

The production of commercially available products marketed to contain silver nanoparticles is rapidly increasing. Species-specific toxicity is a phenomenon associated with many elements, including silver, making it imperative to develop a method to identify and quantify the various forms of silver (namely, silver ions vs. silver nanoparticles) possibly present in these products. In this study a method was developed using high performance liquid chromatography (HPLC) with ultraviolet (UV-VIS) and inductively coupled mass spectrometric (ICP-MS) detection to separate starch stabilized silver nanoparticles (AgNPs) and silver ions (Ag+) by cation exchange chromatography with 0.5 M nitric acid mobile phase. The silver nanoparticles and ions were baseline resolved with an ICP-MS response linear over four orders of magnitude, 0.04 mg kg- 1 detection limit, and 90% chromatographic recovery for silver solutions containing ions and starch stabilized silver nanoparticles smaller than 100 nm.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mokhtari, Narges; Daneshpajouh, Shahram; Seyedbagheri, Seyedali

This study has investigated different visible-light irradiation's effect on the formation of silver nanoparticles from silver nitrate using the culture supernatant of Klebsiella pneumonia. Our study shows that visible-light emission can significantly prompt the synthesis of silver nanoparticles. Also, the study experimentally investigated the liquid mixing process effect on silver nanoparticle synthesis by visible-light irradiation. This study successfully synthesized uniformly dispersed silver nanoparticles with a uniform size and shape in the range of 1-6 nm with an average size of 3 nm. Furthermore, the study investigated the mechanism of the reduction of silver ions by culture supernatant of K. pneumonia,more » and used X-ray diffraction to characterize silver chloride as an intermediate compound. Silver chloride was prepared synthetically and used as a substrate for the synthesis of silver nanoparticles by culture supernatant of K. pneumonia. The silver nanoparticles have been prepared from silver chloride during this investigation for the first time.« less

Silver deposition and tissue staining associated with wound dressings containing silver.

PubMed

Walker, Michael; Cochrane, Christine A; Bowler, Philip G; Parsons, David; Bradshaw, Peter

2006-01-01

Argyria is the general term used to denote a clinical condition in which excessive administration and deposition of silver causes a permanent irreversible gray-blue discoloration of the skin or mucous membranes. The amount of discoloration usually depends on the route of silver delivery (ie, oral or topical administration) along with the body's ability to absorb and excrete the administered silver compound. Argyria is accepted as a rare dermatosis but once silver particles are deposited, they remain immobile and may accumulate during the aging process. Topical application of silver salts (eg, silver nitrate solution) may lead to transient skin staining. To investigate their potential to cause skin staining, two silver-containing dressings (Hydrofiber and nanocrystalline) were applied to human skin samples taken from electively amputated lower limbs. The potential for skin discoloration was assayed using atomic absorption spectroscopy. When the dressings were hydrated with water, a significantly higher amount of silver was released from the nanocrystalline dressing compared to the Hydrofiber dressing (P <0.005), which resulted in approximately 30 times more silver deposition. In contrast, when saline was used as the hydration medium, the release rates were low for both dressings and not significantly different (silver deposition was minimal). Controlling the amount of silver released from silver-containing dressings should help reduce excessive deposition of silver into wound tissue and minimize skin staining.

Preparation of starch-stabilized silver nanoparticles from amylose-sodium palmitate inclusion complexes

USDA-ARS?s Scientific Manuscript database

Starch-stabilized silver nanoparticles were prepared from amylose-sodium palmitate complexes by first converting sodium palmitate to silver palmitate by reaction with silver nitrate and then reducing the silver ion to metallic silver. This process produced water solutions that could be dried and the...

Cost-effectiveness Analysis of Silver Delivery Approaches in the Management of Partial-thickness Burns.

PubMed

Nherera, Leo; Trueman, Paul; Roberts, Christopher; Berg, Leena

2018-02-23

Burn injury is a common type of traumatic injury that causes considerable morbidity and mortality, resulting in about 30,000 admissions annually in specialist burn centers and costing around $1 billion per year in the United States. One percent silver sulfadiazine has been utilized widely in the management of burns and newer silver dressings are on the market, including nanocrystalline silver dressings, silver-impregnated hydrofiber dressings, and silver-impregnated foam dressings. This study sought to determine the cost effectiveness of the newer silver dressings using clinical data from an indirect treatment comparison using silver sulfadiazine as the baseline. A decision analytic model was developed from a US payer's perspective for burn patients with a total body surface area of < 20%. Outcomes were length of stay, infections and incidence of surgical procedures, quality adjusted life years (QALYs), and cost. The meta-analysis reported a statistically significant reduction in length of hospital stay and clinically important reductions in infections and incidence of surgical procedures in favor of the silver barrier dressing compared with other silver dressings. The estimated QALYs were 0.970 versus 0.969 versus 0.969 and mean cost per patient was $15,892, $23,799, and $24,269 for the nanocrystalline silver dressing, silver-impregnated hydrofiber dressing, and silver-impregnated foam dressing, respectively. The analysis showed the nanocrystalline silver dressing to be a dominant strategy (less costly with better outcomes). These findings were robust to a range of sensitivity analyses. According to data from an indirect treatment comparison, this analysis suggests that nanocrystalline silver dressing is the most cost-effective silver delivery system. Prospective head-to-head research on the costs and outcomes of these silver delivery systems in this patient population is necessary to validate the results of this economic evaluation.

Physicochemical properties of protein-modified silver nanoparticles in seawater

NASA Astrophysics Data System (ADS)

Zhong, Hangyue

2013-10-01

This study investigated the physicochemical properties of silver nanoparticles stabilized with casein protein in seawater. UV?vis spectrometry, dynamic light scattering (DLS), and transmission electron microscopy (TEM) were applied to measure the stability of silver nanoparticles in seawater samples. The obtained results show an increased aggregation tendency of silver nanoparticles in seawater, which could be attributed its relatively high cation concentration that could neutralize the negatively charges adsorbed on the surface of silver nanoparticles and reduce the electrostatic repulsion forces between nanoparticles. Similarly, due to the surface charge screening process, the zeta potential of silver nanoparticles in seawater decreased. This observation further supported the aggregation behavior of silver nanoparticles. This study also investigated the dissolution of silver nanoparticles in seawater. Result shows that the silver nanoparticle dissolution in DI water is lower than in seawater, which is attributed to the high Cl? concentration present in seawater. As Cl? can react with silver and form soluble AgCl complex, dissolution of silver nanoparticles was enhanced. Finally, this study demonstrated that silver nanoparticles are destabilized in seawater condition. These results may be helpful in understanding the environmental risk of discharged silver nanoparticles in seawater conditions.

80. GENERAL VIEW TO NORTH ON 3RD AVENUE EL AT ...

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

80. GENERAL VIEW TO NORTH ON 3RD AVENUE EL AT GUN HILL STATION. 7TH AVENUE EL EXPRESS IS VISIBLE ABOVE THE 3RD AVENUE EL WHICH JOINED ONTO THE SAME STRUCTURE AT GUN HILL ROAD. NOTE: GUN HILL ROAD IS THE NORTH TERMINUS OF THE 3RD AVENUE ELEVATED. TRAINS DID NOT CARRY PASSENGERS BEYOND THIS POINT, ALTHOUGH THE 3RD AVENUE TRACK DID EXTEND FURTHER NORTH FOR SWITCHING PURPOSES AND INTO THE YARDS. - Interborough Rapid Transit Company, Third Avenue Elevated Line, Borough of the Bronx, New York County, NY

Silver in medicine: a brief history BC 335 to present.

PubMed

Barillo, David J; Marx, David E

2014-12-01

Silver is a naturally occurring element. Similar to other metals, the ionized form of silver (Ag(+1)) has known antimicrobial properties. A number of wound dressings incorporating silver ion or silver compounds have recently been developed and marketed. In addition, the antimicrobial effects of silver are currently being promoted in consumer products such as clothing and household appliances. The present use of silver in medical and consumer products has prompted concerns for potential toxicity and ecological effects, including induction of microbial resistance to antibiotics. These concerns ignore the fact that silver has been used for medicinal purposes for several thousand years. A historical review of the uses of silver in medicine is presented.

The Electrodeposition of Silver from Supercritical Carbon Dioxide/Acetonitrile

PubMed Central

Bartlett, Philip N; Perdjon-Abel, Magdalena; Cook, David; Reid, Gillian; Levason, William; Cheng, Fei; Zhang, Wenjian; George, Michael W; Ke, Jie; Beanland, Richard; Sloan, Jeremy

2014-01-01

Cyclic voltammetry of silver coordination complexes in acetonitrile and in a single-phase supercritical carbon dioxide/acetonitrile (scCO2/CH3CN) system is reported. Five silver precursors are investigated: (1,5-cyclooctadiene)(hexafluoroacetylacetonato) silver(I) [Ag(hfac)(COD)], (hexafluoroacetylacetonato)(triphenylphosphine) silver(I) [Ag(hfac)(PPh3)], (perfluorooctanoato)bis(triphenylphosphine) silver(I) [Ag(CF3(CF2)6CO2)(PPh3)2], tetrakis(triphenylphosphine) silver(I) tetrafluoroborate [Ag(PPh3)4][BF4] and tetrakis(acetonitrile) silver(I) tetrafluoroborate [Ag(CH3CN)4][BF4]. Of these, [Ag(CH3CN)4][BF4] is found to be the most suitable for electrodeposition of silver from scCO2/CH3CN.

Room temperature synthesis of silver nanowires from tabular silver bromide crystals in the presence of gelatin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu Suwen; Wehmschulte, Rudolf J.; Lian Guoda

2006-03-15

Long silver nanowires were synthesized at room temperature by a simple and fast process derived from the development of photographic films. A film consisting of an emulsion of tabular silver bromide grains in gelatin was treated with a photographic developer (4-(methylamino)phenol sulfate (metol), citric acid) in the presence of additional aqueous silver nitrate. The silver nanowires have lengths of more than 50 {mu}m, some even more than 100 {mu}m, and average diameters of about 80 nm. Approximately, 70% of the metallic silver formed in the reduction consists of silver nanowires. Selected area electron diffraction (SAED) results indicate that the silvermore » nanowires grow along the [111] direction. It was found that the presence of gelatin, tabular silver bromide crystals and silver ions in solution are essential for the formation of the silver nanowires. The nanowires appear to originate from the edges of the silver bromide crystals. They were characterized by transmission electron microscopy (TEM), SAED, scanning electron microscopy (SEM), and powder X-ray diffraction (XRD)« less

A review of the antibacterial effects of silver nanomaterials and potential implications for human health and the environment

NASA Astrophysics Data System (ADS)

Marambio-Jones, Catalina; Hoek, Eric M. V.

2010-06-01

Here, we present a review of the antibacterial effects of silver nanomaterials, including proposed antibacterial mechanisms and possible toxicity to higher organisms. For purpose of this review, silver nanomaterials include silver nanoparticles, stabilized silver salts, silver-dendrimer, polymer and metal oxide composites, and silver-impregnated zeolite and activated carbon materials. While there is some evidence that silver nanoparticles can directly damage bacteria cell membranes, silver nanomaterials appear to exert bacteriocidal activity predominantly through release of silver ions followed (individually or in combination) by increased membrane permeability, loss of the proton motive force, inducing de-energization of the cells and efflux of phosphate, leakage of cellular content, and disruption DNA replication. Eukaryotic cells could be similarly impacted by most of these mechanisms and, indeed, a small but growing body of literature supports this concern. Most antimicrobial studies are performed in simple aquatic media or cell culture media without proper characterization of silver nanomaterial stability (aggregation, dissolution, and re-precipitation). Silver nanoparticle stability is governed by particle size, shape, and capping agents as well as solution pH, ionic strength, specific ions and ligands, and organic macromolecules—all of which influence silver nanoparticle stability and bioavailability. Although none of the studies reviewed definitively proved any immediate impacts to human health or the environment by a silver nanomaterial containing product, the entirety of the science reviewed suggests some caution and further research are warranted given the already widespread and rapidly growing use of silver nanomaterials.

Migration of silver from commercial plastic food containers and implications for consumer exposure assessment.

PubMed

von Goetz, Natalie; Fabricius, Lars; Glaus, Reto; Weitbrecht, Volker; Günther, Detlef; Hungerbühler, Konrad

2013-01-01

Food storage containers with embedded silver as an antibacterial agent promise longer durability of food. For risk assessment the release of this silver into the stored food and resulting human exposure need to be known. For the purpose of exposure assessment, silver migration from commercial plastic containers with declared content of 'nano-' or 'micro-silver' into different food simulants (water, 10% ethanol, 3% acetic acid, olive oil) was quantitatively determined by ICP-MS and the form of the released silver was investigated. The highest migration of silver was observed for the acidic food simulant with 30 ng silver cm(-2) contact surface within 10 days at 20°C. In a second and third use cycle, migration dropped by a factor of up to 10, so that the maximum cumulated release over three use cycles was 34 ng cm(-2). The silver release over time was described using a power function and a numerical model that simulates Fickian diffusion through the plastic material. The released silver was found to be in ionic form, but also in the form of silver nanoparticles (around 12%). Consumer exposure to the total amount of silver released from the food containers is low in comparison with the background silver exposure of the general population, but since natural background concentrations are only known for ionic silver, the exposure to silver nanoparticles is not directly comparable with a safe background level.

Quantification of metal loading to Silver Creek through the Silver Maple Claims area, Park City, Utah, May 2002

USGS Publications Warehouse

Kimball, Briant A.; Johnson, Kevin K.; Runkel, Robert L.; Steiger, Judy I.

2004-01-01

The Silver Maple Claims area along Silver Creek, near Park City, Utah, is administered by the Bureau of Land Management. To quantify possible sources of elevated zinc concentrations in Silver Creek that exceed water-quality standards, the U.S. Geological Survey conducted a mass-loading study in May 2002 along a 1,400-meter reach of Silver Creek that included the Silver Maple Claims area. Additional samples were collected upstream and downstream from the injection reach to investigate other possible sources of zinc and other metals to the stream. Many metals were investigated in the study, but zinc is of particular concern for water-quality standards. The total loading of zinc along the study reach from Park City to Wanship, Utah, was about 49 kilograms per day. The Silver Maple Claims area contributed about 38 percent of this load. The Silver Creek tailings discharge pipe, which empties just inside the Silver Maple Claims area, contributed more than half the load of the Silver Maple Claims area. Substantial zinc loads also were added to Silver Creek downstream from the Silver Maple Claims area. Ground-water discharge upstream from the waste-water treatment plant contributed 20 percent of the total zinc load, and another 17 percent was contributed near the waste-water treatment plant. By identifying the specific areas where zinc and other metal loads are contributed to Silver Creek, it is possible to assess the needs of a remediation plan. For example, removing the tailings from the Silver Maple Claims area could contribute to lowering the zinc concentration in Silver Creek, but without also addressing the loading from the Silver Creek tailings discharge pipe and the ground-water discharge farther downstream, the zinc concentration could not be lowered enough to meet water-quality standards. Additional existing sources of zinc loading downstream from the Silver Maple Claims area could complicate the process of lowering zinc concentration to meet water-quality standards.

Plasmonic characterization of photo-induced silver nanoparticles extracted from silver halide based TEM film

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sudheer,, E-mail: sudheer@rrcat.gov.in; Tiwari, P.; Rai, V. N.

The plasmonic responses of silver nanoparticles extracted from silver halide based electron microscope film are investigated. Photo-reduction process is carried out to convert the silver halide grains into the metallic silver. The centrifuge technique is used for separating the silver nanoparticles from the residual solution. Morphological study performed by field emission scanning electron microscope (FESEM) shows that all the nanoparticles have an average diameter of ~120 nm with a high degree of mono dispersion in size. The localized surface plasmon resonance (LSPR) absorption peak at ~537 nm confirms the presence of large size silver nanoparticles.

Silver ion-mediated killing of a food pathogen: Melting curve analysis data of silver resistance genes and growth curve data.

PubMed

Gokulan, Kuppan; Williams, Katherine; Khare, Sangeeta

2017-04-01

Limited antibacterial activity of silver ions leached from silver-impregnated food contact materials could be due to: 1) the presence of silver resistance genes in tested bacteria ; or 2) lack of susceptibility to silver ion-mediated killing in the bacterial strain (K. Williams, L. Valencia, K. Gokulan, R. Trbojevich, S. Khare, 2016 [1]). This study contains data to address the specificity of silver resistance genes in Salmonella Typhimurium during the real time PCR using melting curve analysis and an assessment of the minimum inhibitory concentration of silver ions for Salmonella .

Plasmonic particles of colloidal silver in high-resolution recording media

NASA Astrophysics Data System (ADS)

Andreeva, O. V.; Andreeva, N. V.; Kuzmina, T. B.

2017-01-01

The optical properties of colloidal silver particles formed photographically in high-resolution silver halide photographic materials have been considered. The conditions that allow one to obtain exposed and developed light-sensitive silver halide particles in the form of colloidal particles of metallic silver having the properties of localized plasmons have been described. The results of the studies of the developed silver particles in traditional photographic materials for image holography and in nanoporous silver halide photographic materials for volume holography have been presented. The perspectives of using plasmonic silver nanoparticles produced photographically have been discussed.

Rapid deposition of triangular silver nanoplates on planar surfaces: application to metal-enhanced fluorescence.

PubMed

Aslan, Kadir; Lakowicz, Joseph R; Geddes, Chris D

2005-04-07

A simple and rapid wet-chemical technique for the deposition of silver triangles on conventional glass substrates, which alleviates the need for lithography, has been developed. The technique is based on the seed-mediated cetyltrimethylammonium-bromide-directed growth of silver triangles on glass surfaces, where smaller spherical silver seeds that were attached to the surface were subsequently converted and grown into silver triangles in the presence of a cationic surfactant and silver ions. The size of the silver triangles was controlled by sequential immersion of silver seed-coated glass substrates into a growth solution and by the duration time of immersion. Atomic force microscopy studies revealed that the size of the silver triangles ranged between 100 and 500 nm. Interestingly, these new surfaces are a significant improvement over traditional silver island films for applications in metal-enhanced fluorescence. A routine 16-fold enhancement in emission intensity was typically observed, for protein-immobilized indocyanine green, with a relatively very low loading density of silver triangles on the glass surface.

High purity silver microcrystals recovered from silver wastes by eco-friendly process using hydrogen peroxide.

PubMed

Gatemala, Harnchana; Ekgasit, Sanong; Wongravee, Kanet

2017-07-01

A simple, rapid, and environmentally friendly process using hydrogen peroxide, was developed for recovering high purity silver directly from industry and laboratory wastes. Silver ammine complex, [Ag(NH 3 ) 2 ] + Cl - , derived from AgCl were generated and then directly reduced using H 2 O 2 to reliably turn into high purity microcrystalline silver (99.99%) examined by EDS and XRD. Morphology of the recovered silver microcrystals could be selectively tuned by an addition of poly(vinyl pyrrolidone). The main parameters in the recovering process including pH, concentration of Ag + and the mole ratio of H 2 O 2 :Ag + were carefully optimized though the central composite design (CCD). The optimized condition was employed for a trial recovery of 50 L silver ammine complex prepared from a collection of silver-wastes during 3-year research on industrial nanoparticle production. The recovered silver microcrystals >700 g could be recovered with 91.27%. The remaining solution after filtering of the recovered silver microcrystals can be used repeatedly (at least 8 cycles) without losing recovery efficiency. Matrix interferences including Pb 2+ and Cl - play a minimal role in our silver recovery process. Furthermore, the direct usage of the recovered silver microcrystals was demonstrated by using as a raw material of silver clay for creating a set of wearable silver jewelries. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mechanical, electrical, and thermal expansion properties of carbon nanotube-based silver and silver-palladium alloy composites

NASA Astrophysics Data System (ADS)

Pal, Hemant; Sharma, Vimal

2014-11-01

The mechanical, electrical, and thermal expansion properties of carbon nanotube (CNT)-based silver and silver-palladium (10:1, w/w) alloy nanocomposites are reported. To tailor the properties of silver, CNTs were incorporated into a silver matrix by a modified molecular level-mixing process. CNTs interact weakly with silver because of their non-reactive nature and lack of mutual solubility. Therefore, palladium was utilized as an alloying element to improve interfacial adhesion. Comparative microstructural characterizations and property evaluations of the nanocomposites were performed. The structural characterizations revealed that decorated type-CNTs were dispersed, embedded, and anchored into the silver matrix. The experimental results indicated that the modification of the silver and silver-palladium nanocomposite with CNT resulted in increases in the hardness and Young's modulus along with concomitant decreases in the electrical conductivity and the coefficient of thermal expansion (CTE). The hardness and Young's modulus of the nanocomposites were increased by 30%-40% whereas the CTE was decreased to 50%-60% of the CTE of silver. The significantly improved CTE and the mechanical properties of the CNT-reinforced silver and silver-palladium nanocomposites are correlated with the intriguing properties of CNTs and with good interfacial adhesion between the CNTs and silver as a result of the fabrication process and the contact action of palladium as an alloying element.

Determination of land subsidence related to ground-water-level declines using Global Positioning System and leveling surveys in Antelope Valley, Los Angeles and Kern counties, California, 1992

USGS Publications Warehouse

Ikehara, M.E.; Phillips, S.P.

1994-01-01

A large-scale, land-subsidence monitoring network for Antelope Valley, California, was established, and positions and elevations for 85 stations were measured using Global Positioning System geodetic surveying in spring 1992. The 95-percent confidence (2@) level of accuracy for the elevations calculated for a multiple-constraint adjustment generally ranged from +0.010 meter (0.032 foot) to +0.024 meter (0.078 foot). The magnitudes and rates of land subsidence as of 1992 were calculated for several periods for 218 bench marks throughout Antelope Valley. The maximum measured magnitude of land subsidence that occurred between 1926 and 1992 was 6.0 feet (1.83 meters) at BM 474 near Avenue I and Sierra Highway. Measured or estimated subsidence of 2-7 feet (.61-2.l3 meters) had occurred in a 210- square-mile (542-square-kilometer) area of Antelope Valley, generally bounded by Avenue K, Avenue A, 90th Street West, and 120th Street East, during the same period. Land subsidence in Antelope Valley is caused by aquifer-system compaction, which is related to ground-water-level declines and the presence of fine-grained, compressible sediments. Comparison of potentiomethric-surface, water-level decline, and subsidence-rate maps for several periods indicated a general correlation between water-level declines and the distribution and rate of subsidence in the Lancaster ground-water subbasin. A conservative estimate of the amount of the reduction in storage capacity of the aquifer system in the Lancaster subbasin is about 50,000 acre-feet in the area that has been affected by more than one foot (.30 meters) of subsidence as of 1992. Information on the history of ground-water levels and the distribution and thickness of fine-grained compressible sediments can be used to mitigate continued land subsidence. Future monitoring of ground-water levels and land-surface elevations in subsidence-sensitive regions of Antelope Valley may be an effective means to manage land subsidence.

21 CFR 310.548 - Drug products containing colloidal silver ingredients or silver salts offered over-the-counter...

Code of Federal Regulations, 2011 CFR

2011-04-01

... ingredients or silver salts offered over-the-counter (OTC) for the treatment and/or prevention of disease. 310...) for the treatment and/or prevention of disease. (a) Colloidal silver ingredients and silver salts have... disease conditions. There are serious and complicating aspects to many of the diseases these silver...

21 CFR 310.548 - Drug products containing colloidal silver ingredients or silver salts offered over-the-counter...

Code of Federal Regulations, 2010 CFR

2010-04-01

... ingredients or silver salts offered over-the-counter (OTC) for the treatment and/or prevention of disease. 310...) for the treatment and/or prevention of disease. (a) Colloidal silver ingredients and silver salts have... disease conditions. There are serious and complicating aspects to many of the diseases these silver...

21 CFR 310.548 - Drug products containing colloidal silver ingredients or silver salts offered over-the-counter...

Code of Federal Regulations, 2013 CFR

2013-04-01

... ingredients or silver salts offered over-the-counter (OTC) for the treatment and/or prevention of disease. 310...) for the treatment and/or prevention of disease. (a) Colloidal silver ingredients and silver salts have... disease conditions. There are serious and complicating aspects to many of the diseases these silver...

21 CFR 310.548 - Drug products containing colloidal silver ingredients or silver salts offered over-the-counter...

Code of Federal Regulations, 2012 CFR

2012-04-01

... ingredients or silver salts offered over-the-counter (OTC) for the treatment and/or prevention of disease. 310...) for the treatment and/or prevention of disease. (a) Colloidal silver ingredients and silver salts have... disease conditions. There are serious and complicating aspects to many of the diseases these silver...

21 CFR 310.548 - Drug products containing colloidal silver ingredients or silver salts offered over-the-counter...

Code of Federal Regulations, 2014 CFR

2014-04-01

... ingredients or silver salts offered over-the-counter (OTC) for the treatment and/or prevention of disease. 310...) for the treatment and/or prevention of disease. (a) Colloidal silver ingredients and silver salts have... disease conditions. There are serious and complicating aspects to many of the diseases these silver...

77 FR 61661 - Price for the American Eagle Silver Proof and Uncirculated Coins and the America the Beautiful...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-10

... DEPARTMENT OF THE TREASURY United States Mint Price for the American Eagle Silver Proof and... price of silver, the United States Mint is raising the price of its American Eagle Silver Proof and... price 2012 American Eagle Silver Proof $59.95 2012 American Eagle Silver Uncirculated 50.95 2011...

Mechanism of Prophylaxis by Silver Compounds against Infection of Burns

PubMed Central

Ricketts, C. R.; Lowbury, E. J. L.; Lawrence, J. C.; Hall, M.; Wilkins, M. D.

1970-01-01

To clarify tthe mechanism by which local application of silver compounds protects burns against infection, an ion-specific electrode was used to measùre the concentration of silver ions in solutions. By this method it was shown that in burn dressings silver ions were reduced to a very low level by precipitation as silver chloride. The antibacterial effect was found to depend on the availability of silver ions from solution in contact with precipitate. Between 10-5 and 10-6 molar silver nitrate solution in water was rapidly bactericidal. The minimal amount of silver nitrate causing inhibition of respiration of skin in tissue culture was about 25 times the minimal concentration of silver nitrate that inhibited growth of Pseudomonas aeruginosa. PMID:4986877

Comment on "A re-assessment of the safety of silver in household water treatment: rapid systematic review of mammalian in vivo genotoxicity studies".

PubMed

Lantagne, Daniele; Rayner, Justine; Mittelman, Anjuliee; Pennell, Kurt

2017-11-13

We wish to thank Fewtrell, Majuru, and Hunter for their article highlighting genotoxic risks associated with the use of particulate silver for primary drinking water treatment. The recent promotion of colloidal silver products for household water treatment in developing countries is problematic due to previously identified concerns regarding manufacturing quality and questionable advertising practices, as well as the low efficiency of silver nanoparticles to treat bacteria, viruses, and protozoa in source waters. However, in the conclusion statement of the manuscript, Fewtrell et al. state, "Before colloidal Ag or AgNP are used in filter matrices for drinking water treatment, consideration needs to be given to how much silver is likely to be released from the matrix during the life of the filter." Unfortunately, it appears Fewtrell et al. were unaware that studies of silver nanoparticle and silver ion elution from ceramic filters manufactured and used in developing countries have already been completed. These existing studies have found that: 1) silver ions, not silver nanoparticles, are eluted from ceramic filters treated with silver nanoparticles or silver nitrate; and, 2) silver ions have not been shown to be genotoxic. Thus, the existing recommendation of applying silver nanoparticles to ceramic filters to prevent biofilm formation within the filter and improve microbiological efficacy should still be adhered to, as there is no identified risk to people who drink water from ceramic filters treated with silver nanoparticles or silver nitrate. We note that efforts should continue to minimize exposure to silver nanoparticles (and silica) to employees in ceramic filter factories in collaboration with the organizations that provide technical assistance to ceramic filter factories.

New Paradigm Shift for the Green Synthesis of Antibacterial Silver Nanoparticles Utilizing Plant Extracts

PubMed Central

2014-01-01

This review covers general information regarding the green synthesis of antibacterial silver nanoparticles. Owing to their antibacterial properties, silver nanoparticles are widely used in many areas, especially biomedical applications. In green synthesis practices, the chemical reducing agents are eliminated, and biological entities are utilized to convert silver ions to silver nanoparticles. Among the various biological entities, natural plant extracts have emerged as green reducing agents, providing eco-friendly routes for the preparation of silver nanomaterials. The most obvious merits of green synthesis are the increased biocompatibility of the resulting silver nanoparticles and the ease with which the reaction can be carried out. This review summarizes some of the plant extracts that are used to produce antibacterial silver nanoparticles. Additionally, background information regarding the green synthesis and antibacterial activity of silver nanoparticles is provided. Finally, the toxicological aspects of silver nanoparticles are briefly mentioned. PMID:25343010

Silver Recycling in the United States in 2000

USGS Publications Warehouse

Hilliard, Henry E.

2003-01-01

In 2000, the global silver supply deficit (the difference between mine and scrap supply and silver demand) was more than 3,000 metric tons. U.S. silver demand for photographic applications alone was nearly equal to annual U.S. silver production. Until 1968, the U.S. silver deficit was filled by withdrawals from the U.S. Treasury reserves. In 2000, the deficit was filled by destocking, imports, and recycling. Photographic wastes, spent catalysts, and electronic scrap are the major sources of materials for silver recycling. Nearly 1,800 tons of silver contained in these materials were available for recycling in 2000. Other recyclable silver-bearing materials include dental alloys, jewelry, and silverware. In 2000, an estimated 1,700 tons of silver were recovered from secondary sources in the United States. The U.S. recycling efficiency for old scrap was calculated to have been 97 percent in 2000; the recycling rate was estimated to be 32 percent.

Silver recycling in the United States in 2000

USGS Publications Warehouse

Hilliard, Henry E.

2003-01-01

In 2000, the global silver supply deficit (the difference between mine and scrap supply and silver demand) was more than 3,000 metric tons. U.S. silver demand for photographic applications alone was nearly equal to annual U.S. silver production. Until 1968, the U.S. silver deficit was filled by withdrawals from the U.S. Treasury reserves. In 2000, the deficit was filled by destocking, imports, and recycling. Photographic wastes, spent catalysts, and electronic scrap are the major sources of materials for silver recycling. Nearly 1,800 metric tons of silver contained in these materials were available for recycling in 2000. Other recyclable silver-bearing materials include dental alloys, jewelry, and silverware. In 2000, an estimated 1,700 tons of silver were recovered from secondary sources in the United States. The U.S. recycling efficiency for old scrap was calculated to have been 97 percent in 2000; the recycling rate was estimated to be 32 percent.

Silver distribution and release from an antimicrobial denture base resin containing silver colloidal nanoparticles.

PubMed

Monteiro, Douglas Roberto; Gorup, Luiz Fernando; Takamiya, Aline Satie; de Camargo, Emerson Rodrigues; Filho, Adhemar Colla Ruvolo; Barbosa, Debora Barros

2012-01-01

The aim of this study was to evaluate a denture base resin containing silver colloidal nanoparticles through morphological analysis to check the distribution and dispersion of these particles in the polymer and by testing the silver release in deionized water at different time periods. A Lucitone 550 denture resin was used, and silver nanoparticles were synthesized by reduction of silver nitrate with sodium citrate. The acrylic resin was prepared in accordance with the manufacturers' instructions, and silver nanoparticle suspension was added to the acrylic resin monomer in different concentrations (0.05, 0.5, and 5 vol% silver colloidal). Controls devoid of silver nanoparticles were included. The specimens were stored in deionized water at 37°C for 7, 15, 30, 60, and 120 days, and each solution was analyzed using atomic absorption spectroscopy. Silver was not detected in deionized water regardless of the silver nanoparticles added to the resin and of the storage period. Micrographs showed that with lower concentrations, the distribution of silver nanoparticles was reduced, whereas their dispersion was improved in the polymer. Moreover, after 120 days of storage, nanoparticles were mainly located on the surface of the nanocomposite specimens. Incorporation of silver nanoparticles in the acrylic resin was evidenced. Moreover, silver was not detected by the detection limit of the atomic absorption spectrophotometer used in this study, even after 120 days of storage in deionized water. Silver nanoparticles are incorporated in the PMMA denture resin to attain an effective antimicrobial material to help control common infections involving oral mucosal tissues in complete denture wearers. © 2011 by the American College of Prosthodontists.

Unprecedented Silver Resistance in Clinically Isolated Enterobacteriaceae: Major Implications for Burn and Wound Management

PubMed Central

Norton, Rhy; Austin, Cindy; Mitchell, Amber; Zank, Sara; Durham, Paul

2015-01-01

Increased utilization of inorganic silver as an adjunctive to many medical devices has raised concerns of emergent silver resistance in clinical bacteria. Although the molecular basis for silver resistance has been previously characterized, to date, significant phenotypic expression of these genes in clinical settings is yet to be observed. Here, we identified the first strains of clinical bacteria expressing silver resistance at a level that could significantly impact wound care and the use of silver-based dressings. Screening of 859 clinical isolates confirmed 31 harbored at least 1 silver resistance gene. Despite the presence of these genes, MIC testing revealed most of the bacteria displayed little or no increase in resistance to ionic silver (200 to 300 μM Ag+). However, 2 isolates (Klebsiella pneumonia and Enterobacter cloacae) were capable of robust growth at exceedingly high silver concentrations, with MIC values reaching 5,500 μM Ag+. DNA sequencing of these two strains revealed the presence of genes homologous to known genetic determinants of heavy metal resistance. Darkening of the bacteria's pigment was observed after exposure to high silver concentrations. Scanning electron microscopy images showed the presence of silver nanoparticles embedded in the extracellular polymeric substance of both isolates. This finding suggested that the isolates may neutralize ionic silver via reduction to elemental silver. Antimicrobial testing revealed both organisms to be completely resistant to many commercially available silver-impregnated burn and wound dressings. Taken together, these findings provide the first evidence of clinical bacteria capable of expressing silver resistance at levels that could significantly impact wound management. PMID:26014954

Similarities and Differences between Silver Ions and Silver in Nanoforms as Antibacterial Agents

PubMed Central

Kędziora, Anna; Speruda, Mateusz; Rybka, Jacek; Łukowiak, Anna; Bugla-Płoskońska, Gabriela

2018-01-01

Silver is considered as antibacterial agent with well-known mode of action and bacterial resistance against it is well described. The development of nanotechnology provided different methods for the modification of the chemical and physical structure of silver, which may increase its antibacterial potential. The physico-chemical properties of silver nanoparticles and their interaction with living cells differs substantially from those of silver ions. Moreover, the variety of the forms and characteristics of various silver nanoparticles are also responsible for differences in their antibacterial mode of action and probably bacterial mechanism of resistance. The paper discusses in details the aforementioned aspects of silver activity. PMID:29393866

The dual role of silver during silicon etching in HF solution.

PubMed

Abouda-Lachiheb, Manel; Nafie, Nesma; Bouaicha, Mongi

2012-08-13

It was reported that during silicon etching, silver was subjected to have a controversial role. Some researchers debate that silver protects silicon, and, at the same time, other ones confirm that silver catalyzes silicon underneath. In this paper, we give experimental results arguing the dual role that silver has during the formation of silicon nanostructures. We give a proof that the role of silver depends on the experimental details and the intrinsic properties of silver during its deposition on the silicon wafer. Through our investigations, we tracked the silver particles that indicated which mechanism is involved. Characterizations of the prepared samples were made using a scanning electron microscope.

Colored and semitransparent silver nanoparticle layers deposited by spin coating of silver nanoink

NASA Astrophysics Data System (ADS)

Yoon, Hoi Jin; Jo, Yejin; Jeong, Sunho; Lim, Jung Wook; Lee, Seung-Yun

2018-05-01

In this letter, we report on the fabrication and characterization of colored and semitransparent silver nanoparticle layers. A spin coating of silver nanoink is used to deposit silver nanoparticle layers onto substrates. The transmittance and color of the silver nanoparticle layers are significantly dependent on the spin speed and nanoink concentration, owing to variations in the size and distribution of the nanoparticles. Both color variation and efficiency improvement are achieved with the application of silver nanoparticles to semitransparent Si thin-film solar cells, which is associated with the excitation of the dipole or quadruple plasmon modes of the silver nanoparticles.

Silver nanoparticles: A new view on mechanistic aspects on antimicrobial activity.

PubMed

Durán, Nelson; Durán, Marcela; de Jesus, Marcelo Bispo; Seabra, Amedea B; Fávaro, Wagner J; Nakazato, Gerson

2016-04-01

Silver nanoparticles are well known potent antimicrobial agents. Although significant progresses have been achieved on the elucidation of antimicrobial mechanism of silver nanoparticles, the exact mechanism of action is still not completely known. This overview incorporates a retrospective of previous reviews published and recent original contributions on the progress of research on antimicrobial mechanisms of silver nanoparticles. The main topics discussed include release of silver nanoparticles and silver ions, cell membrane damage, DNA interaction, free radical generation, bacterial resistance and the relationship of resistance to silver ions versus resistance to silver nanoparticles. The focus of the overview is to summarize the current knowledge in the field of antibacterial activity of silver nanoparticles. The possibility that pathogenic microbes may develop resistance to silver nanoparticles is also discussed. Antibacterial effect of nanoscopic silver generated a lot of interest both in research projects and in practical applications. However, the exact mechanism is still will have to be elucidated. This overview incorporates a retrospective of previous reviews published from 2007 to 2013 and recent original contributions on the progress of research on antimicrobial mechanisms to summarize our current knowledge in the field of antibacterial activity of silver nanoparticles. Copyright © 2015 Elsevier Inc. All rights reserved.

In situ green synthesis and characterization of sericin-silver nanoparticle composite with effective antibacterial activity and good biocompatibility.

PubMed

He, Huawei; Tao, Gang; Wang, Yejing; Cai, Rui; Guo, Pengchao; Chen, Liqun; Zuo, Hua; Zhao, Ping; Xia, Qingyou

2017-11-01

Silver nanoparticle has been widely applied to a variety of fields for its outstanding antimicrobial activity. However, the stability of silver nanoparticle limits its application under certain conditions. Thus, improving the stability of silver nanoparticle via biosynthesis is a promising shortcut to expand its application. Sericin from silkworm cocoon has good hydrophilicity, reaction activity, biocompatibility and biodegradability. In this study, we developed a novel, simple, one-step biosynthesis method to prepare sericin-silver nanoparticle composite in situ in solution. Sericin served as the reductant of silver ion, the dispersant and stabilizer of the prepared sericin-silver nanoparticle composite. Natural light was the only power source used to catalyze the synthesis of silver nanoparticle in situ in solution. The novel sericin-silver nanoparticle composite was characterized by ultraviolet-visible and fluorescence spectroscopy, X-ray diffraction, transmission electron microscopy and fourier transform infrared spectroscopy. The results showed silver nanoparticle could be synthesized through the reduction of AgNO 3 by the phenolic hydroxyl group of tyrosine residues of sericin under the catalysis of natural light. The synthesized silver nanoparticle had good crystalline, size distribution and long-term stability at room temperature. Light irradiation was essential for the preparation of sericin-silver nanoparticle composite. The antibacterial activity assay showed 25mg/L and 100mg/L were the minimum concentrations of sericin-silver nanoparticle composite required to inhibit the growth of Staphylococcus aureus and kill this bacterium, respectively. The cytotoxicity assay showed cell viability and cell growth were almost not affected by sericin-silver nanoparticle composite under the concentration of 25mg/L. Our study suggested the preparation of sericin-silver nanoparticle composite was environmentally friendly and energy conservation, and the prepared sericin-silver nanoparticle composite had long-term stability, effective antibacterial activity and good biocompatibility. This novel sericin-silver nanoparticle composite has shown great potentials for biomedical application such as antibacterial agent and wound care. Copyright © 2017 Elsevier B.V. All rights reserved.

Analyzing silver concentration in soil using laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Prasetyo, S.; Isnaeni; Zaitun; Mitchell, K.; Suliyanti, M. M.; Herbani, Y.

2018-03-01

Determination of concentration of heavy metal ions in soil, such as silver, is very important to study soil pollution levels. Several techniques have been developed to determine silver ion concentration in soil. In this paper, we utilized laser-induced breakdown spectroscopy (LIBS) to study silver concentration in soil. We used four different data analysis methods to calculate silver concentration. In this case, we prepared soil samples with different silver ion concentrations from 400 ppm to 1000 ppm. Our analysis was focused on the 843.15 nm silver atomic absorption line. We found that plasma intensity increased as silver concentration increased. Our findings were based on our analysis using four different analysis methods. We believe that these analysis methods are able to calculate silver concentration in soil using LIBS.

Characterization of engineered nanoparticles in commercially available spray disinfectant products advertised to contain colloidal silver.

PubMed

Rogers, Kim R; Navratilova, Jana; Stefaniak, Aleksandr; Bowers, Lauren; Knepp, Alycia K; Al-Abed, Souhail R; Potter, Phillip; Gitipour, Alireza; Radwan, Islam; Nelson, Clay; Bradham, Karen D

2018-04-01

Given the potential for human exposure to silver nanoparticles from spray disinfectants and dietary supplements, we characterized the silver-containing nanoparticles in 22 commercial products that advertised the use of silver or colloidal silver as the active ingredient. Characterization parameters included: total silver, fractionated silver (particulate and dissolved), primary particle size distribution, hydrodynamic diameter, particle number, and plasmon resonance absorbance. A high degree of variability between claimed and measured values for total silver was observed. Only 7 of the products showed total silver concentrations within 20% of their nominally reported values. In addition, significant variations in the relative percentages of particulate vs. soluble silver were also measured in many of these products reporting to be colloidal. Primary silver particle size distributions by transmission electron microscopy (TEM) showed two populations of particles - smaller particles (<5nm) and larger particles between 20 and 40nm. Hydrodynamic diameter measurements using nanoparticle tracking analysis (NTA) correlated well with TEM analysis for the larger particles. Z-average (Z-Avg) values measured using dynamic light scattering (DLS); however, were typically larger than both NTA or TEM particle diameters. Plasmon resonance absorbance signatures (peak absorbance at around 400nm indicative of metallic silver nanoparticles) were only noted in 4 of the 9 yellow-brown colored suspensions. Although the total silver concentrations were variable among products, ranging from 0.54mg/L to 960mg/L, silver containing nanoparticles were identified in all of the product suspensions by TEM. Published by Elsevier B.V.

Silver Flakes and Silver Dendrites for Hybrid Electrically Conductive Adhesives with Enhanced Conductivity

NASA Astrophysics Data System (ADS)

Ma, Hongru; Li, Zhuo; Tian, Xun; Yan, Shaocun; Li, Zhe; Guo, Xuhong; Ma, Yanqing; Ma, Lei

2018-03-01

Silver dendrites were prepared by a facile replacement reaction between silver nitrate and zinc microparticles of 20 μm in size. The influence of reactant molar ratio, reaction solution volume, silver nitrate concentration, and reaction time on the morphology of dendrites was investigated systematically. It was found that uniform tree-like silver structures are synthesized under the optimal conditions. Their structure can be described as a trunk, symmetrical branches, and leaves, which length scales of 5-10, 1-2 μm, and 100-300 nm, respectively. All features were systematically characterized by scanning electron microscopy, transmission electron microscopy (TEM), high-resolution TEM, and x-ray powder diffraction. A hybrid fillers system using silver flakes and dendrites as electrically conductive adhesives (ECAs) exhibited excellent overall performance. This good conductivity can be attributed mainly to the synergy between the silver microflakes (5-20 μm sized irregular sheet structures) and dendrites, allowing more conductive pathways to be formed between the fillers. In order to further optimize the overall electrical conductivity, various mixtures of silver microflakes and silver dendrites were tested in ECAs, with results indicating that the highest conductivity was shown when the amounts of silver microflakes, silver dendrites and the polymer matrix were 69.4 wt.% (20.82 vol.%), 0.6 wt.% (0.18 vol.%), and 30.0 wt.% (79.00 vol.%), respectively. The corresponding mass ratio of silver flakes to silver dendrites was 347:3. The resistivity of ECAs reached as low as 1.7 × 10-4 Ω cm.

Multilevel modeling of retention and disinfection efficacy of silver nanoparticles on ceramic water filters.

PubMed

Mikelonis, Anne M; Lawler, Desmond F; Passalacqua, Paola

2016-10-01

This research examined how variations in synthesis methods of silver nanoparticles affect both the release of silver from ceramic water filters (CWFs) and disinfection efficacy. The silver nanoparticles used were stabilized by four different molecules: citrate, polyvinylpyrrolidone, branched polyethylenimine, and casein. A multilevel statistical model was built to quantify if there was a significant difference in: a) extent of silver lost, b) initial amount of silver lost, c) silver lost for water of different quality, and d) total coliform removal. Experiments were performed on location at Pure Home Water, a CWF factory in Tamale, Ghana using stored rainwater and dugout water (a local surface water). The results indicated that using dugout vs. rainwater significantly affects the initial (p-value 0.0015) and sustained (p-value 0.0124) loss of silver, but that silver type does not have a significant effect. On average, dugout water removed 37.5μg/L more initial silver and had 1.1μg/L more silver in the filtrate than rainwater. Initially, filters achieved 1.9 log reduction values (LRVs) on average, but among different silver and water types this varied by as much as 2.5 LRV units. Overall, bacterial removal effectiveness was more challenging to evaluate, but some data suggest that the branched polyethylenimine silver nanoparticles provided improved initial bacterial removal over filters which were not painted with silver nanoparticles (p-value 0.038). Copyright © 2016 Elsevier B.V. All rights reserved.

Silver removal from aqueous solution by biochar produced from biosolids via microwave pyrolysis.

PubMed

Antunes, Elsa; Jacob, Mohan V; Brodie, Graham; Schneider, Philip A

2017-12-01

The contamination of water with silver has increased due to the widespread applications of products with silver employed as antimicrobial agent. Adsorption is a cost-effective method for silver removal from aqueous solution. In this study biochar, produced from the microwave assisted pyrolysis of biosolids, was used for silver removal from an aqueous solution. The adsorption kinetics, isotherms and thermodynamics were investigated to better understand the silver removal process by biochar. X-ray diffraction results demonstrated that silver removal was a combination two consecutive mechanisms, reduction and physical adsorption. The Langmuir model fitted the experimental data well, showing that silver removal was predominantly a surface mechanism. The thermodynamic investigation demonstrated that silver removal by biochar was an exothermic process. The final nanocomposite Ag-biochar (biochar plus silver) was used for methylene blue adsorption and photodegradation. This study showed the potential of using biochar produced from biosolids for silver removal as a promising solution to mitigate water pollution and an environmentally sustainable approach for biosolids management and re-use. Copyright © 2017 Elsevier Ltd. All rights reserved.

An investigation of in vivo wound healing activity of biologically synthesized silver nanoparticles

NASA Astrophysics Data System (ADS)

Kaler, Abhishek; Mittal, Amit Kumar; Katariya, Mahesh; Harde, Harshad; Agrawal, Ashish Kumar; Jain, Sanyog; Banerjee, Uttam Chand

2014-09-01

Therapeutic use of nano-silver is claimed to have reduced side effects and enhanced curative activity as compared to its ionic counterpart (silver ions). The present work aims to screen microbes for the synthesis of silver nanoparticles (AgNPs), to formulate the nano-silver-based Carbopol gel and evaluating its wound healing efficacy on rat model. The goal was to develop the topical formulation based on bio-nano-silver to control the infection and healing the wounds with higher efficacy. Procedure involved the use of Saccharomyces boulardii for the synthesis of silver nanoparticles in the size range of 3-10 nm and these nanoparticles were used for the preparation of Carbopol-based nano-silver gel. Highly stable Carbopol nanogel was developed with good rheological properties. The burn wound healing potential of this nano-silver gel was evaluated on SD rats via visual observation, transepidermal water loss and histology of skin. Excellent wound healing was observed with AgNPs. Biologically synthesized AgNPs-based nano-silver gel showed superior wound healing efficacy as compared to marketed formulations and silver ions.

Branchial versus intestinal silver toxicity and uptake in the marine teleost Parophrys vetulus.

PubMed

Grosell, M; Wood, C M

2001-10-01

Exposure to elevated waterborne silver as AgNO3 (4.07 microM=448 microg l(-1)) in seawater resulted in osmoregulatory disturbance in the lemon sole (Parophrys vetulus). The main effects were increased plasma Na+ and Cl- concentrations which translated into increased plasma osmolality. Plasma Mg2+ levels were also slightly increased after 96 h exposure. Using radioisotopic flux measurements, a 50% reduction in branchial unidirectional Na+ extrusion was observed after 48 h silver exposure. By applying an intestinal perfusion approach, we were able to separate and thus quantify the intestinal contribution to the observed silver-induced physiological disturbance and internal silver accumulation. This analysis revealed that the intestinal contribution to silver-induced ionoregulatory toxicity was as high as 50-60%. In marked contrast, internal silver accumulation (in liver and kidney) was found to be derived exclusively from uptake across the gills. Drinking of silver-contaminated seawater resulted in substantial silver accumulation in the intestinal tissue (but apparently not silver uptake across the intestine), which probably explains the intestinal contribution to silver-induced physiological disturbance.

7. View looking northwest along Cedar Avenue Bridge. Delaware, ...

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

7. View looking northwest along Cedar Avenue Bridge. - Delaware, Lackawanna & Western Railroad, Scranton Yards, Cedar Avenue Bridge, Spanning Cedar Avenue at Railroad Alley, Scranton, Lackawanna County, PA

Argyria secondary to ingestion of homemade silver solution.

PubMed

Brandt, Douglas; Park, Betty; Hoang, Mai; Jacobe, Heidi T

2005-08-01

Argyria is a rare skin disease caused by cutaneous deposition of silver granules in the skin as a result of exposure to silver substrate or ingestion of silver salt. This report describes a patient with generalized argyria caused by ingestion of homemade colloidal silver solution. The patient learned about the uses of the silver solution and its preparation at a convention for "natural medicine."

Biopersistence of silver nanoparticles in tissues from Sprague–Dawley rats

PubMed Central

2013-01-01

Silver nanoparticles are known to be distributed in many tissues after oral or inhalation exposure. Thus, understanding the tissue clearance of such distributed nanoparticles is very important to understand the behavior of silver nanoparticles in vivo. For risk assessment purposes, easy clearance indicates a lower overall cumulative toxicity. Accordingly, to investigate the clearance of tissue silver concentrations following oral silver nanoparticle exposure, Sprague–Dawley rats were assigned to 3 groups: control, low dose (100 mg/kg body weight), and high dose (500 mg/kg body weight), and exposed to two different sizes of silver nanoparticles (average diameter 10 and 25 nm) over 28 days. Thereafter, the rats were allowed to recover for 4 months. Regardless of the silver nanoparticle size, the silver content in most tissues gradually decreased during the 4-month recovery period, indicating tissue clearance of the accumulated silver. The exceptions were the silver concentrations in the brain and testes, which did not clear well, even after the 4-month recovery period, indicating an obstruction in transporting the accumulated silver out of these tissues. Therefore, the results showed that the size of the silver nanoparticles did not affect their tissue distribution. Furthermore, biological barriers, such as the blood–brain barrier and blood-testis barrier, seemed to play an important role in the silver clearance from these tissues. PMID:24059869

X-Ray Absorption Near-Edge Structure (XANES) Spectroscopy Study of the Interaction of Silver Ions with Staphylococcus aureus, Listeria monocytogenes, and Escherichia coli

PubMed Central

Zanzen, Ulrike; Krishna, Katla Sai; Hormes, Josef

2013-01-01

Silver ions are widely used as antibacterial agents, but the basic molecular mechanism of this effect is still poorly understood. X-ray absorption near-edge structure (XANES) spectroscopy at the Ag LIII, S K, and P K edges reveals the chemical forms of silver in Staphylococcus aureus and Escherichia coli (Ag+ treated). The Ag LIII-edge XANES spectra of the bacteria are all slightly different and very different from the spectra of silver ions (silver nitrate and silver acetate), which confirms that a reaction occurs. Death or inactivation of bacteria was observed by plate counting and light microscopy. Silver bonding to sulfhydryl groups (Ag-S) in cysteine and Ag-N or Ag-O bonding in histidine, alanine, and dl-aspartic acid was detected by using synthesized silver-amino acids. Significantly lower silver-cysteine content, coupled with higher silver-histidine content, in Gram-positive S. aureus and Listeria monocytogenes cells indicates that the peptidoglycan multilayer could be buffering the biocidal effect of silver on Gram-positive bacteria, at least in part. Bonding of silver to phosphate groups was not detected. Interaction with DNA or proteins can occur through Ag-N bonding. The formation of silver-cysteine can be confirmed for both bacterial cell types, which supports the hypothesis that enzyme-catalyzed reactions and the electron transport chain within the cell are disrupted. PMID:23934494

Accuracy, precision, usability, and cost of portable silver test methods for ceramic filter factories.

PubMed

Meade, Rhiana D; Murray, Anna L; Mittelman, Anjuliee M; Rayner, Justine; Lantagne, Daniele S

2017-02-01

Locally manufactured ceramic water filters are one effective household drinking water treatment technology. During manufacturing, silver nanoparticles or silver nitrate are applied to prevent microbiological growth within the filter and increase bacterial removal efficacy. Currently, there is no recommendation for manufacturers to test silver concentrations of application solutions or filtered water. We identified six commercially available silver test strips, kits, and meters, and evaluated them by: (1) measuring in quintuplicate six samples from 100 to 1,000 mg/L (application range) and six samples from 0.0 to 1.0 mg/L (effluent range) of silver nanoparticles and silver nitrate to determine accuracy and precision; (2) conducting volunteer testing to assess ease-of-use; and (3) comparing costs. We found no method accurately detected silver nanoparticles, and accuracy ranged from 4 to 91% measurement error for silver nitrate samples. Most methods were precise, but only one method could test both application and effluent concentration ranges of silver nitrate. Volunteers considered test strip methods easiest. The cost for 100 tests ranged from 36 to 1,600 USD. We found no currently available method accurately and precisely measured both silver types at reasonable cost and ease-of-use, thus these methods are not recommended to manufacturers. We recommend development of field-appropriate methods that accurately and precisely measure silver nanoparticle and silver nitrate concentrations.

Silver Dissolution and Release from Ceramic Water Filters.

PubMed

Mittelman, Anjuliee M; Lantagne, Daniele S; Rayner, Justine; Pennell, Kurt D

2015-07-21

Application of silver nanoparticles (nAg) or silver nitrate (AgNO3) has been shown to improve the microbiological efficacy of ceramic water filters used for household water treatment. Silver release, however, can lead to undesirable health effects and reduced filter effectiveness over time. The objectives of this study were to evaluate the contribution of nanoparticle detachment, dissolution, and cation exchange to silver elution, and to estimate silver retention under different influent water chemistries. Dissolved silver (Ag(+)) and nAg release from filter disks painted with 0.03 mg/g casein-coated nAg or AgNO3 were measured as a function of pH (5-9), ionic strength (1-50 mM), and cation species (Na(+), Ca(2+), Mg(2+)). Silver elution was controlled by dissolution as Ag(+) and subsequent cation exchange reactions regardless of the applied silver form. Effluent silver levels fell below the drinking water standard (0.1 mg/L) after flushing with 30-42 pore volumes of pH 7, 10 mM NaNO3 at pH 7. When the influent water was at pH 5, contained divalent cations or 50 mM NaNO3, silver concentrations were 5-10 times above the standard. Our findings support regular filter replacement and indicate that saline, hard, or acidic waters should be avoided to minimize effluent silver concentrations and preserve silver treatment integrity.

4. Underside and southeast end of Cedar Avenue Bridge. ...

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

4. Underside and southeast end of Cedar Avenue Bridge. - Delaware, Lackawanna & Western Railroad, Scranton Yards, Cedar Avenue Bridge, Spanning Cedar Avenue at Railroad Alley, Scranton, Lackawanna County, PA

8. Perspective view of Cedar Avenue Bridge looking east. ...

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

8. Perspective view of Cedar Avenue Bridge looking east. - Delaware, Lackawanna & Western Railroad, Scranton Yards, Cedar Avenue Bridge, Spanning Cedar Avenue at Railroad Alley, Scranton, Lackawanna County, PA

Preliminary flight prototype silver ion monitoring system

NASA Technical Reports Server (NTRS)

Brady, J.

1974-01-01

The design, fabrication, and testing of a preliminary flight prototype silver ion monitoring system based on potentiometric principles and utilizing a solid-state silver sulfide electrode paired with a pressurized double-junction reference electrode housing a replaceable electrolyte reservoir is described. The design provides automatic electronic calibration utilizing saturated silver bromide solution as a silver ion standard. The problem of loss of silver ion from recirculating fluid, its cause, and corrective procedures are reported. The instability of the silver sulfide electrode is discussed as well as difficulties met in implementing the autocalibration procedure.

Photochemical Synthesis of Silver Nanodecahedrons and Related Nanostructures for Plasmonic Field Enhancement Applications

NASA Astrophysics Data System (ADS)

Lu, Haifei

Noble-metal nanocrystals have received considerable attention in recent years for their size and shape dependent localized surface Plasmon resonances (LSPR). Various applications based on colloidal nanoparticles, such as surface enhanced Raman scattering (SERS), surface enhanced fluorescence (SEF), plasmonic sensing, photothermal therapy etc., have been broadly explored in the field of biomedicine, because of their extremely large optical scattering and absorption cross sections, as well as giant electric field enhancement on their surface. However, despite its high chemical stability, gold exhibits quite large losses and electric field enhancement is comparatively weaker than silver. Silver nanoparticles synthesized by the traditional technique only cover an LSPR ranged from 420~500 nm. On the other hand, the range of 500~660 nm, which is covered by several easily available commercial laser lines, very limited colloidal silver nanostructures with controllable size and shape have been reported, and realization of tuning the resonance to longer wavelengths is very important for the practical applications. In this thesis, a systematic study on photochemical synthesis of silver nanodecahedrons (NDs) and related nanostructures, and their plasmonic field enhancements are presented. First, the roles of chemicals and the light source during the formation of silver nanoparticles have been studied. We have also developed a preparation route for the production size-controlled silver nanodecahedrons (LSPR range 420 ~ 660 nm) in high purity. Indeed our experiments indicate that both the chemicals and the light sources can affect the shape and purity of final products. Adjusting the molar ratio between sodium citrate and silver nitrate can help to control the crystal structure following rapid reduction from sodium borohydride. Light from a blue LED (465 nm) can efficiently transform the polyvinylpyrrolidone stabilized small silver nanoparticles into silver NDs through photo excitation. These silver NDs acting as seeds can be re-grown into larger silver NDs with LSPR ranging from 490 nm to 590 nm, upon receiving LED irradiation with emission close to the LSPR of silver ND seeds, which are suspended in a precursor solution containing small silver nanoparticles. With the aid of centrifugation, silver NDs with high purity can be obtained. Furthermore, silver ND with a broad tuning range (LSPR 490 ~ 660 nm) can be synthesized from these seeds using irradiation from a 500 nm LED. Second, the optical properties of silver NDs and their SERS application for sensitive molecular detection are presented. Raman signal obtained from silver NDs show remarkable advantage over noble nanoparticles of other shaped, thus revealing their strong localized field enhancement. Experimental results demonstrate that average enhancement factor from individual silver ND may be as high as 106. In order to explore their application for biosensing and bioimaging, stable silica coated SERS tags based on silver ND producing high Raman intensity have been studied. Our experiment results indicate that 10-8 M 4-MBA in solution can be detected by silver NDs modified silicon chip through SERS. Simulation result on the geometry of silver ND/silica spacer/gold film/substrate shows that the Raman sensitivity of the NDs modified chip can be further improved with the insertion of a dielectric/conductor film between them. Finally, we present a photochemical method for the preparation of silver nanostructures preparation with the use of 633 nm laser. Silver nanostructures composed of silver nanoplates could be grown from small silver nanoparticles deposited on a glass substrate. The periodicity of the silver nanostructures is several micrometers, revealing that this photochemical method has the potential for "writing" silver pattern on a solid substrate. Raman spectroscopy has also been explored for real-time monitoring of silver nanostructure growth and SERS hotspots formation.

Antibacterial Effect of Silver Diamine Fluoride on Cariogenic Organisms.

PubMed

Lou, Yali; Darvell, Brain W; Botelho, Michael G

2018-05-01

To screen the possible antimicrobial activity of a range of clinically used, silver-based compounds on cariogenic organisms: silver diamine fluoride (SDF), silver fluoride, and silver nitrate. Preliminary screening disk-diffusion susceptibility tests were conducted on Mueller-Hinton agar plates inoculated with Streptococcus mutans, Lactobacillus acidophilus, and Actinomyces naeslundii, organisms known to be cariogenic. In order to identify which component of the silver compounds was responsible for any antibacterial (AB) effect, and to provide controls, the following were also investigated at high and low concentrations: sodium fluoride, ammonium fluoride, ammonium chloride, sodium fluoride, sodium chloride, and sodium nitrate, as well as deionized water as control. A volume of 10 pL of a test solution was dispensed onto a paper disk resting on the inoculated agar surface, and the plate incubated anaerobically at 37°C for 48 hours. The zones of inhibition were then measured. Silver diamine fluoride, silver fluoride, silver nitrate, and ammonium fluoride had significant AB effect (p < 0.05) on all three test organisms, although ammonium fluoride had no effect at low concentration; the remaining other compounds had no effect. Silver ions appear to be the principal AB agent at both high and low concentration; fluoride ions only have an AB effect at high concentration, while ammonium, nitrate, chloride and sodium ions have none. The anticaries effect of topical silver solutions appears restricted to that of the silver ions. Silver compounds, such as SDF, silver fluoride, and silver nitrate have AB effect against cariogenic organisms and these may have clinical impact in arresting or preventing dental decay. Sodium fluoride did not have AB effect under the conditions tested.

The concentration effect of capping agent for synthesis of silver nanowire by using the polyol method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Jian-Yang; Hsueh, Yu-Lee; Huang, Jung-Jie, E-mail: jjhuang@mdu.edu.tw

2014-06-01

Silver nanowires were synthesized by the polyol method employing ethylene glycol, Poly(N-vinylpyrrolidone) (PVP) and silver nitrate (AgNO{sub 3}) as the precursors. Most of the studies used metal salts (PtCl{sub 2}, NaCl) as seed precursor to synthesize the silver nanowires. In the study, the metal salts were not used and the concentration of capping agent was changed to observe the aspect ratio of silver nanowires. The experimental results showed that controlling synthesis temperature, Poly(N-vinylpyrrolidone) (PVP) molecular weight, reactant concentrations, and addition rates of AgNO{sub 3} affects the growth characteristics of silver nanowires. Field-emission scanning electron microscopy, UV–vis spectrophotometry, and X-ray diffractometrymore » were employed to characterize the silver nanowires. As increasing the concentration of PVP, the silver nanowire diameter widened and resulted in a smaller aspect ratio. We successfully prepared silver nanowires (diameter: 170 nm, length: 20 μm). The silver nanowire thin film suspension showed high transmittance, low sheet resistance, and may be used for transparent conductive film applications. - Graphical abstract: The FE-SEM image shows that nanostructures with considerable quantities of silver nanowires can also be produced when the PVP (Mw=360 K)/AgNO{sub 3} molar ratio was 2.5. - Highlights: • The polyol method was used to synthesize of silver nanowire. • The metal seed precursors were not used before synthesizing the silver nanowires. • The silver nanowire diameter and length was 170 nm and 20 μm, respectively. • Silver nanowire film with high transmittance (>85%) and low sheet resistance (<110 Ω/sq)« less

XPS characterization of silver exchanged ETS-10 and mordenite molecular sieves.

PubMed

Anson, A; Maham, Y; Lin, C C H; Kuznicki, T M; Kuznicki, S M

2009-05-01

Silver exchanged molecular sieves ETS-10 (Ag-ETS-10) and mordenite (Ag-mordenite) were dehydrated under vacuum at temperatures between 100 degrees C-350 degrees C. Changes in the state of the silver were studied using X-ray photoelectron spectroscopy (XPS). Silver cations in titanosilicate Ag-ETS-10 are fully reduced to Ag(0) at temperatures as low as 150 degrees C. The characteristic features of the XPS spectrum of silver in this Ag-ETS-10 species correspond to only metallic silver. The signal for metallic silver is not observed in the XPS spectrum of aluminosilicate Ag-mordenite, indicating that silver cations are not reduced, even after heating to 350 degrees C.

The dual role of silver during silicon etching in HF solution

PubMed Central

2012-01-01

It was reported that during silicon etching, silver was subjected to have a controversial role. Some researchers debate that silver protects silicon, and, at the same time, other ones confirm that silver catalyzes silicon underneath. In this paper, we give experimental results arguing the dual role that silver has during the formation of silicon nanostructures. We give a proof that the role of silver depends on the experimental details and the intrinsic properties of silver during its deposition on the silicon wafer. Through our investigations, we tracked the silver particles that indicated which mechanism is involved. Characterizations of the prepared samples were made using a scanning electron microscope. PMID:22888998

1. OBLIQUE VIEW LOOKING WEST FROM 21ST STREET VIADUCT (SOUTHSIDE) ...

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

1. OBLIQUE VIEW LOOKING WEST FROM 21ST STREET VIADUCT (SOUTHSIDE) 2000 BLOCK OF MORRIS AVENUE AND HEAVIEST CORNER ON EARTH DISTRICT AT FIRST AVENUE NORTH AND 20TH STREET (CENTER TOP) - Morris Avenue Warehouse District, 2000-2400 blocks of Morris Avenue & 2100-2500 blocks of First Avenue, North, Birmingham, Jefferson County, AL

Overview taken from Facility 2 looking east down Avenue E ...

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

Overview taken from Facility 2 looking east down Avenue E (Russell Avenue). Facility 1 is on left, Facility 1G and 1C in center. View facing east - U.S. Naval Base, Pearl Harbor, Administration Annex, Near Russell Avenue (previously Avenue E), between of Facility Nos. 1C & 1E , Pearl City, Honolulu County, HI

Antibacterial potency of V.A.C. GranuFoam Silver(®) Dressing.

PubMed

Sachsenmaier, Saskia; Peschel, Andreas; Ipach, Ingmar; Kluba, Torsten

2013-10-01

V.A.C.(®) GranuFoam™ therapy is regularly used in the surgical therapy of infected wounds and soft tissue injuries. Silver nanoparticles can destroy bacterial cell walls and inhibit enzymes for cell replication. Silver dressings are therefore successfully used for many indications in wound therapy. In this study, we investigated the antimicrobial potency of ionic silver released from the silver-coated V.A.C.(®) GranuFoam™ during vacuum therapy. Silver dressing was exposed to agar plates populated with bacteria to measure silver release. A total of 15 agar plates colonised with either Staphylococcus aureus populations or with Staphylococcus epidermidis, were loaded with V.A.C. GranuFoam Silver(®) Dressing polyurethane foam (KCI, San Antonio, Texas). Each of 13 pieces of silver-coated foam was applied to an agar plate. Two plates were loaded with conventional black foam without any coating. After connecting to a vacuum pump, the vacuum therapy of the 15 plates lasted 5 days. The zone of inhibition of bacterial growth around the foam was measured daily. Silver release was also determined as a function of time. At each time point, there was evidence of silver in the agar independent of bacterial colonisation. The S. aureus agar showed a consecutive increase in silver concentration from baseline upon 48 h after exposure to the negative pressure of V.A.C. therapy. An increasing mean silver level after 48, 72 and 96 h was measured under V.A.C. therapy with a peak value after 120 h. In contrast, the results from the S. epidermidis plates did not follow a linear pattern. At the beginning of vacuum therapy, we documented a rise in silver concentration. After 48-96h, the silver levels fluctuated. A maximum zone of inhibition in both bacterial colonised plates (S. aureus and S. epidermidis) was found 39 h after the start of the V.A.C. GranuFoam Silver(®) therapy. From our results, we confirmed the antimicrobial effect of the silver ions against S. aureus and S. epidermidis under continuous V.A.C. GranuFoam(®) Silver therapy with a negative pressure of 25 mmHg. Furthermore we could quantify the amounts of silver, which were released from the foam under negative pressure as a function of time. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of silver-doping on the crystal structure, morphology and photocatalytic activity of TiO2 nanofibers

NASA Astrophysics Data System (ADS)

Barakat, N. A. M.; Kim, H. Y.

2012-09-01

In this study, effect of sliver-doping on the crystal structure, the nanofibrous morphology and the photocatalytic activity of titanium oxide nanofibers have been investigated. Silver-doped TiO2 nanofibers having different silver contents were prepared by calcination of electrospun nanofiber mats consisting of silver nitrate, titanium isopropoxide and poly(vinyl acetate) at 600 °C. The results affirmed formation of silver-doped TiO2 nanofibers composed of anatase and rutile when the silver nitrate content in the original electrospun solution was more than 3 wt%. The rutile phase content was directly proportional with the AgNO3 concentration in the electrospun solution. Negative impact of the silver-doping on the nanofibrous morphology was observed as increase the silver content caused to decrease the aspect ratio, i.e. producing nanorods rather nanofibers. However, silver-doping leads to modify the surface roughness. Study of the photocatalytic degradation of methylene blue dye clarified that increase the silver content strongly enhances the dye oxidation process.

Electrically Conductive Silver Paste Obtained by Use of Silver Neodecanoate as Precursor

NASA Astrophysics Data System (ADS)

Shen, Longguang; Liu, Jianguo; Zeng, Xiaoyan; Ren, Zhao

2015-02-01

An electrically conductive silver paste has been prepared from an organometallic compound, silver neodecanoate, as silver precursor. The precursor was highly soluble in organic solvents and decomposed into metallic silver at low sintering temperatures (<200°C). Thermogravimetric analysis showed the silver content of the paste was approximately 25 wt.%. Viscosity studies indicated the paste was a pseudoplastic liquid with viscosity in the range 6.5-9 Pa s. The paste was compatible with the micro-pen direct-writing process, enabling production of silver lines on a substrate. The electrical resistivity of the silver lines was 9 × 10-6 Ω cm after sintering at 115°C for 60 min, 5.8 × 10-6 Ω cm when sintered at 150°C for 60 min, and 3 × 10-6 Ω cm when sintered above 300°C, values which are similar to those of bulk silver. Hence, the prepared paste can be successfully used on flexible substrates such as polymers.

ENTRY ON SOUTHEAST SIDE (WILLISTON AVENUE ENTRY), VIEW FACING NORTHWEST. ...

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

ENTRY ON SOUTHEAST SIDE (WILLISTON AVENUE ENTRY), VIEW FACING NORTHWEST. - Schofield Barracks Military Reservation, Quadrangle I Administration Building, Williston Avenue between Wright-Smith & Reilly Avenues, Wahiawa, Honolulu County, HI

Synthesis and characterization of silver nanowires with zigzag morphology in N, N-dimethylformamide

NASA Astrophysics Data System (ADS)

He, Xin; Zhao, Xiujian; Chen, Yunxia; Feng, Jinyang; Sun, Zhenya

2007-08-01

Zigzag silver nanowires with a uniform diameter of 20±5 nm were prepared by reducing silver nitrate (AgNO 3) with N, N-dimethylformamide (DMF) in the presence of tetrabutyl titanate (TBT) and acetylacetone (AcAc) at 373 K for 18 h. X-ray and selected area electron diffraction (XRD and SAED) patterns reveal that the prepared product is made of pure silver with face centered cubic structure. Transmission electron microscopy (TEM) investigations suggest that the amount of silver nanowires is enhanced with increase in reaction time, and the end-to-end assemblies of silver nanorods are observed during the reaction process. After 18 h reaction, silver nanowires with zigzag morphology are obtained. In this paper, a possible growth process of silver nanowires with this interesting shape is described. Silver nanoparticles with small sizes were obtained by reducing Ag + ions with DMF, providing seeds for homogeneous growth of silver nanorods. With the extending reaction time, the synthesized silver nanorods were connected in an end-to-end manner, and the interface between the connections of two nanorods gradually disappeared. The final product shows zigzag morphology with various angles. The angles between two connecting straight parts of zigzag nanowires exhibit an alterable range of 74-151°. These silver nanowires show tremendous potential applications in future nanoscale electronic circuits.

Exposure-related health effects of silver and silver compounds: a review.

PubMed

Drake, Pamela L; Hazelwood, Kyle J

2005-10-01

A critical review of studies examining exposures to the various forms of silver was conducted to determine if some silver species are more toxic than others. The impetus behind conducting this review is that several occupational exposure limits and guidelines exist for silver, but the values for each depend on the form of silver as well as the individual agency making the recommendations. For instance, the American Conference of Governmental Industrial Hygienists has established separate threshold limit values for metallic silver (0.1 mg/m3) and soluble compounds of silver (0.01 mg/m3). On the other hand, the permissible exposure limit (PEL) recommended by the Occupational Safety and Health Administration and the Mine Safety and Health Administration and the recommended exposure limit set by the National Institute for Occupational Safety and Health is 0.01 mg/m3 for all forms of silver. The adverse effects of chronic exposure to silver are a permanent bluish-gray discoloration of the skin (argyria) or eyes (argyrosis). Most studies discuss cases of argyria and argyrosis that have resulted primarily from exposure to the soluble forms of silver. Besides argyria and argyrosis, exposure to soluble silver compounds may produce other toxic effects, including liver and kidney damage, irritation of the eyes, skin, respiratory, and intestinal tract, and changes in blood cells. Metallic silver appears to pose minimal risk to health. The current occupational exposure limits do not reflect the apparent difference in toxicities between soluble and metallic silver; thus, many researchers have recommended that separate PELs be established.

A perspective on the hemolytic activity of chemical and green-synthesized silver and silver oxide nanoparticles

NASA Astrophysics Data System (ADS)

Ashokraja, C.; Sakar, M.; Balakumar, S.

2017-10-01

We report the hemolysis properties of silver and silver oxide nanoparticles (NPs) prepared by chemical and green-synthesis methods. The prepared silver and silver oxide NPs were analyzed using UV-vis spectroscopy to confirm their formation by characterizing their surface plasmon resonance (SPR) and absorption band peaks respectively. The Fourier transmission infrared (FTIR) spectra of the materials showed the characteristic functional groups corresponding to the molecules present in leaf extracts, which is proposed to be acted as reducing and capping agents that are also found on the surface of silver and silver oxide nanoparticles that synthesized via green-synthesis method. Zeta potential analysis revealed the surface charge and stability of the prepared NPs. HRTEM images showed almost spherical shape nanoparticles with an average size of 15.2 and 31.5 nm for wet chemical synthesized silver and silver oxide nanoparticles respectively. In the case of green synthesized silver and silver oxide nanoparticles, it was observed to be 19.4 and 30.4 nm respectively. The order of hemolysis efficacy of the materials is found to be as follows: chemically synthesized Ag2O>  chemically synthesized Ag NPs followed by green-synthesized Ag2O and green-synthesized Ag NPs which showed almost similar hemolysis with respect to concentration. The relatively stable nature of the silver NPs could be attributed to their lower hemolysis efficacy, while the increased lysis properties of silver oxide could be attributed due to reductive/oxidative processes that give rise to the hemolysis through interfacial charge interactions with RBCs.

3. VIEW OF WILLOW CREEK TRESTLE FROM CORNER BASELINE AVENUE ...

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

3. VIEW OF WILLOW CREEK TRESTLE FROM CORNER BASELINE AVENUE AND 185TH AVENUE, FACING NORTHEAST - Oregon Electric Railway Westside Corridor, Between Watson & 185th Avenues, Beaverton, Washington County, OR

Contextual view of building 733 along Cedar Avenue; camera facing ...

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

Contextual view of building 733 along Cedar Avenue; camera facing southwest. - Mare Island Naval Shipyard, WAVES Officers Quarters, Cedar Avenue, west side between Tisdale Avenue & Eighth Street, Vallejo, Solano County, CA

5. Detail of underside of Cedar Avenue Bridge at northwest ...

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

5. Detail of underside of Cedar Avenue Bridge at northwest end. - Delaware, Lackawanna & Western Railroad, Scranton Yards, Cedar Avenue Bridge, Spanning Cedar Avenue at Railroad Alley, Scranton, Lackawanna County, PA

Looking southwest from Idaho Avenue showing east side and north ...

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

Looking southwest from Idaho Avenue showing east side and north end with entrance - University of Idaho, University Classroom Building, Line Street between University Avenue & Idaho Avenue, Moscow, Latah County, ID

Perspective view toward southwest from Idaho Avenue showing east side ...

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

Perspective view toward southwest from Idaho Avenue showing east side and north end - University of Idaho, University Classroom Building, Line Street between University Avenue & Idaho Avenue, Moscow, Latah County, ID

Characterization of engineered nanoparticles in commercially available spray disinfectant products advertised to contain colloidal silver

EPA Science Inventory

Given the potential for human exposure to silver nanoparticles from spray disinfectants and dietary supplements, we characterized the silver-containing nanoparticles in 22 commercial products that advertised the use of silver or colloidal silver as the active ingredient. Characte...

Protective Gel Composition for Treating White Phosphorus Burn Wounds.

DTIC Science & Technology

Water soluble hydrogels of alkali metal alginate and glycerin containing 0.01% to 1% cupric ( copper ) sulfate pentahydrate or silver salts such as...burns. Cupric sulfate pentahydrate of silver salts such as silver acetate, silver lactate monohydrate and silver nitrate in the gel reacts with the

78 FR 47778 - The Boeing Company Boeing Commercial Aircraft (BCA) Auburn, Washington; The Boeing Company Boeing...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-06

... Building 535 Garden Avenue North, Renton, Washington and 10-18 Building 635 Park Avenue North, Renton... include workers at the 10-16 Building 535 Garden Avenue North, Renton, Washington and 10-18 Building 635... Garden Avenue North and 10-18 Building 635 Park Avenue North, Renton, Washington (TA-W-82,705C), The...

Stable silver/biopolymer hybrid plasmonic nanostructures for high performance surface enhanced raman scattering (SERS)

USDA-ARS?s Scientific Manuscript database

Silver/biopolymer nanoparticles were prepared by adding 100 mg silver nitrate to 2% polyvinyl alcohol solution and reduced the silver nitrate into silver ion using 2 % trisodium citrate for high performance Surface Enhanced Raman Scattering (SERS) substrates. Optical properties of nanoparticle were ...

Mechanism of Silver Sulfadiazine Action on Burn Wound Infections

PubMed Central

Fox, Charles L.; Modak, Shanta M.

1974-01-01

The role of silver and sulfadiazine in the mechanism of action of silver sulfadiazine on burn wound infections was investigated. Silver, but not sulfadiazine, was bound by bacteria. Sulfadiazine did not act as an antibacterial agent in low concentrations, but exhibited specific synergism in combination with subinhibitory levels of silver sulfadiazine. The efficacy of silver sulfadiazine is thought to result from its slow and steady reactions with serum and other sodium chloride-containing body fluids, which permits the slow and sustained delivery of silver ions into the wound environs. In this circumstance, a relatively minute amount of sulfadiazine appears active. PMID:15825409

Synthesis and characterization of bactericidal silver nanoparticles using cultural filtrate of simulated microgravity grown Klebsiella pneumoniae.

PubMed

Kalpana, Duraisamy; Lee, Yang Soo

2013-03-05

Silver nanoparticles were synthesized by biological method using cultural filtrate of Klebsiella pneumoniae cultured under simulated microgravity and silver nitrate solution as precursor. The nanoparticles exhibited typical plasmon absorption maximum of silver nanoparticles between 405 and 407 nm. Spherical silver nanoparticles were found to have size between 15 and 37 nm by TEM analysis. XRD pattern corresponding to planes (111), (200), (220) (311) revealed the crystalline nature of the biosynthesized silver nanoparticles. FTIR spectrum proposed stabilization of silver nanoparticles by the protein molecules present in the cultural filtrate. The silver nanoparticles exhibited high bactericidal activity against Salmonella enterica, Escherichia coli and moderate bactericidal activity against Streptococcus pyogenes. Copyright © 2012 Elsevier Inc. All rights reserved.

Antibacterial properties of Ag-doped hydroxyapatite layers prepared by PLD method

NASA Astrophysics Data System (ADS)

Jelínek, Miroslav; Kocourek, Tomáš; Jurek, Karel; Remsa, Jan; Mikšovský, Jan; Weiserová, Marie; Strnad, Jakub; Luxbacher, Thomas

2010-12-01

Thin hydroxyapatite (HA), silver-doped HA and silver layers were prepared using a pulsed laser deposition method. Doped layers were ablated from silver/HA targets. Amorphous and crystalline films of silver concentrations of 0.06 at.%, 1.2 at.%, 4.4 at.%, 8.3 at.% and 13.7 at.% were synthesized. Topology was studied using scanning electron microscopy and atomic force microscopy. Contact angle and zeta potential measurements were conducted to determine the wettability, surface free energy and electric surface properties. In vivo measurement (using Escherichia coli cells) of antibacterial properties of the HA, silver-doped HA and silver layers was carried out. The best antibacterial results were achieved for silver-doped HA layers of silver concentration higher than 1.2 at.%.

Colloidal silver fabrication using the spark discharge system and its antimicrobial effect on Staphylococcus aureus.

PubMed

Tien, Der-Chi; Tseng, Kuo-Hsiung; Liao, Chih-Yu; Tsung, Tsing-Tshih

2008-10-01

Nanoscale techniques for silver production may assist the resurgence of the medical use of silver, especially given that pathogens are showing increasing resistance to antibiotics. Traditional chemical synthesis methods for colloidal silver (CS) may lead to the presence of toxic chemical species or chemical residues, which may inhibit the effectiveness of CS as an antibacterial agent. To counter these problems a spark discharge system (SDS) was used to fabricate a suspension of colloidal silver in deionized water with no added chemical surfactants. SDS-CS contains both metallic silver nanoparticles (Ag(0)) and ionic silver forms (Ag(+)). The antimicrobial affect of SDS-CS on Staphylococcus aureus was studied. The results show that CS solutions with an ionic silver concentration of 30 ppm or higher are strong enough to destroy S. aureus. In addition, it was found that a solution's antimicrobial potency is directly related to its level of silver ion concentration.

Sunlight-assisted synthesis of colloidal silver nanoparticles using chitosan as reducing agent

NASA Astrophysics Data System (ADS)

Susilowati, E.; Maryani; Ashadi

2018-04-01

The present study we explore an environmentally friendly colloidal silver nanoparticles preparation using chitosan as reducing agent and stabilizer. It develops a new strategy on preparation of silver nanoparticles through the gel phase using sodium hydroxide (NaOH) as accelerator reagent. Sunlight irradiation was employed to assisted reducing process of silver ions to silver nanoparticles. Localized surface plasmon resonance (LSPR) phenomenon of silver nanoparticles was investigated using UV-Vis spectrophotometer. The shape and size of silver particles were analyzed using TEM. The formation of silver nanoparticles was confirmed by the appearance of LSPR absorption peak at 396.0–412.0 nm. The absorption peak of LSPR were affected by NaOH amount, time of sulight irradiation and concentration of AgNO3. The produced silver nanoparticles were spherical with dominant size range of 5 to 8 nm as shown by TEM images. All colloidals were stable without any aggregation for 30 days after preparation.

Sintered silver joints via controlled topography of electronic packaging subcomponents

DOEpatents

Wereszczak, Andrew A.

2014-09-02

Disclosed are sintered silver bonded electronic package subcomponents and methods for making the same. Embodiments of the sintered silver bonded EPSs include topography modification of one or more metal surfaces of semiconductor devices bonded together by the sintered silver joint. The sintered silver bonded EPSs include a first semiconductor device having a first metal surface, the first metal surface having a modified topography that has been chemically etched, grit blasted, uniaxial ground and/or grid sliced connected to a second semiconductor device which may also include a first metal surface with a modified topography, a silver plating layer on the first metal surface of the first semiconductor device and a silver plating layer on the first metal surface of the second semiconductor device and a sintered silver joint between the silver plating layers of the first and second semiconductor devices which bonds the first semiconductor device to the second semiconductor device.

Ink composition for making a conductive silver structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walker, Steven B.; Lewis, Jennifer A.

An ink composition for making a conductive silver structure comprises a silver salt and a complex of (a) a complexing agent and a short chain carboxylic acid or (b) a complexing agent and a salt of a short chain carboxylic acid, according to one embodiment. A method for making a silver structure entails combining a silver salt and a complexing agent, and then adding a short chain carboxylic acid or a salt of the short chain carboxylic acid to the combined silver salt and a complexing agent to form an ink composition. A concentration of the complexing agent in themore » ink composition is reduced to form a concentrated formulation, and the silver salt is reduced to form a conductive silver structure, where the concentrated formulation and the conductive silver structure are formed at a temperature of about 120.degree. C. or less.« less

Green synthesis of silver nanoparticle and silver based chitosan bionanocomposite using stem extract of Saccharum officinarum and assessment of its antibacterial activity

NASA Astrophysics Data System (ADS)

Paulkumar, Kanniah; Gnanajobitha, Gnanadhas; Vanaja, Mahendran; Pavunraj, Manickam; Annadurai, Gurusamy

2017-09-01

Synthesis of nanoparticles and nanocomposites using green route is a major focus of modern nanotechnology. Herein we demonstrate the synthesis of silver nanoparticle and silver based chitosan bionanocomposite using the stem extract of Saccharum officinarum. The absorbance peak at 460 nm in the UV-Vis spectrum reveals the synthesis of silver nanoparticles using the stem extract of Saccharum officinarum. The size of the synthesized silver nanoparticle was in the range of 10-60 nm obtained from transmission electron microscope (TEM) analysis. The presence of silver nanoparticles on the chitosan suspension was identified by scanning electron microscope (SEM) and energy dispersive x-ray spectroscopy (EDS). The presence of possible functional group involved in the reduction of silver metal ions into silver nanoparticles was identified by Fourier transform infrared spectroscopy (FTIR) analysis. The antibacterial activity of the synthesized silver based chitosan bionanocomposite was evaluated against Bacillus subtilis (MTCC 3053), Klebsiella planticola (MTCC 2277), Streptococcus faecalis (ATCC 8043), Pseudomonas aeruginosa (ATCC 9027) and Escherichia coli (ATCC 8739). The antibacterial activity of silver based chitosan bionanocomposite has remarkable scope in medicine, food packaging, textile and pharmaceuticals.

Silver Film Surface Modification by Ion Bombardment Decreases Surface Plasmon Resonance Absorption.

PubMed

Fryauf, David M; Diaz Leon, Juan J; Phillips, Andrew C; Kobayashi, Nobuhiko P

2017-05-10

Silver thin films covered with dielectric films serving as protective coatings are desired for telescope mirrors, but durable coatings have proved elusive. As part of an effort to develop long-lived protected-silver mirrors, silver thin films were deposited by electron beam evaporation using a physical vapor deposition system at the University of California Observatories Astronomical Coatings Lab. The silver films were later covered with a stack of dielectric films utilizing silicon nitride and titanium dioxide deposited by ion-assisted electron beam evaporation to fabricate protected mirrors. In-situ argon ion bombardment was introduced after silver deposition and prior to the deposition of dielectric films to assess its effects on the performance of the mirrors. We found that ion bombardment of the silver influenced surface morphology and reflectivity, and these effects correlated with time between silver deposition and ion bombardment. The overall reflectivity at wavelengths in the range of 350-800 nm was found to improve due to ion bombardment, which was qualitatively interpreted as a result of decreased surface plasmon resonance coupling. We suggest that the observed decrease in coupling is caused by silver grain boundary pinning due to ion bombardment suppressing silver surface diffusion, forming smoother silver-dielectric interfaces.

Comparison on Bactericidal and Cytotoxic Effect of Silver Nanoparticles Synthesized by Different Methods

NASA Astrophysics Data System (ADS)

Mala, R.; Celsia, A. S. Ruby; Malathi Devi, S.; Geerthika, S.

2017-08-01

Biologically synthesized silver nanoparticle are biocompatible for medical applications. The present work is aimed to synthesize silver nanoparticle using the fruit pulp of Tamarindusindica and to evaluate its antibacterial and anticancer activity against lung cancercell lines. Antibacterial activity was assessed by well diffusion method. Cytotoxicity was evaluated using MTT assay. GC-MS of fruit pulp extract showed the presence of levoglucosenone, n-hexadecanoic acid, 9,12-octadecadienoic acid etc. Antioxidant activity of the fruit pulp was determined by DPPH assay, hydrogen peroxide scavenging assay and lipid peroxidation. The size of biologically synthesized silver nanoparticle varied from 50 nm to 76 nm. It was 59 nm to 98 nm for chemically synthesized silver nanoparticle. Biologically synthesized silver nanoparticle showed 26 mm inhibition zone against E. coli and chemically synthesized silver nanoparticle showed 20 mm. Antioxidant activity of fruit extract by DPPH showed 84 % reduction. The IC 50 of biologically synthesized silver nanoparticle against lung cancer cell lines was 48 µg/ml. It was 95 µg/ml for chemically synthesized silver nanoparticle. The increased activity of biologically synthesized silver nanoparticle was due to its smaller size, stability and the bioactive compounds capping the silver nanoparticle extracted from the fruit extract.

Selective recovery of silver from waste low-temperature co-fired ceramic and valorization through silver nanoparticle synthesis.

PubMed

Swain, Basudev; Shin, Dongyoon; Joo, So Yeong; Ahn, Nak Kyoon; Lee, Chan Gi; Yoon, Jin-Ho

2017-11-01

Considering the value of silver metal and silver nanoparticles, the waste generated during manufacturing of low temperature co-fired ceramic (LTCC) were recycled through the simple yet cost effective process by chemical-metallurgy. Followed by leaching optimization, silver was selectively recovered through precipitation. The precipitated silver chloride was valorized though silver nanoparticle synthesis by a simple one-pot greener synthesis route. Through leaching-precipitation optimization, quantitative selective recovery of silver chloride was achieved, followed by homogeneous pure silver nanoparticle about 100nm size were synthesized. The reported recycling process is a simple process, versatile, easy to implement, requires minimum facilities and no specialty chemicals, through which semiconductor manufacturing industry can treat the waste generated during manufacturing of LTCC and reutilize the valorized silver nanoparticles in manufacturing in a close loop process. Our reported process can address issues like; (i) waste disposal, as well as value-added silver recovery, (ii) brings back the material to production stream and address the circular economy, and (iii) can be part of lower the futuristic carbon economy and cradle-to-cradle technology management, simultaneously. Copyright © 2017 Elsevier Ltd. All rights reserved.