Sample records for silver 126

  1. Brain Vulnerability to Repeated Blast Overpressure and Polytrauma

    DTIC Science & Technology

    2010-05-28

    devoid of any obvious cell loss or injury when assessed using either Nissl or Fluoro Jade stains , they consistently showed widespread fiber degeneration...injured brain after thionine (l) or silver (r) staining . experimental parameters (e.g. driver volume, tube position, Mylar membrane thickness, and type...5. Thionine- (top) and silver- (bottom) stained brain sections following exposure to 126 kPa airblast at the mouth of the tube. From Long et al

  2. Electrochemistry of Some New Alkaline Battery Electrodes

    DTIC Science & Technology

    1976-02-01

    1NýT;7 ~~ AFAPI 4TR- 75)aI Electrochemistry of Somwý New Alkaline V CI RG, 0OTNME Dr/ David F., ’Pickett, IM Wayue ’,Hisb’q Mr. R ic ha rd A I Mid...adding ZnO to the electi-olyte (saturated) and usi .j the interc:ell conrec;tor d isr:ussed earlier ,itLh el4cc.roploated zinc ag inst. the silver fo

  3. Study of Transport Properties and Structure of Extended-Chain Polymers.

    DTIC Science & Technology

    1985-09-01

    Thermometric devices disturb temperature. Unfeasible to use guarded electrodes or hotplates ". Surface and volume conductivities mixed. Numerical examples will...gold or aluminum onto appropriate portions of the surface. Alternatively, graphite pastes, silver pastes, conductive cements, or paints can be used. Care... aluminum box which was grounded to provide elec- 158 85 a) TOP VIEW GROUND WIRETELNBS ONNECTORLO samAewi E SHILDE ELIREDE ALUM5 INV O kv~~TO COVERBA7:E

  4. Class A Sodalites: Silver, Sodium, Halosodalites

    DTIC Science & Technology

    1992-05-15

    always possessed Ag 5s and Ag 5 p characteristics while the HOMO orbitals were mixtures of mainly X np (X n = Cl 3, Br 4,15) and Ag 4d orbitals with some...Small Particles, J. Wiley & Sans: N . Y., 1983, p . 132. 1012. Calzaferri, 0.; Forss, L; Hugentobler, T.; Kamber, L ICONC and INPUTC, Fortran software for...nw q U . * e c ,s , aD a m ,,m", h u s ( a in m n ntfu hIh,, - , ,e - - - - . - .. - . ; -.T -?- -/ ~ ~ ~~ w Wtmuf.,cua sltl ro r l fut"O. to w

  5. Nano-structured surface plasmon resonance sensor for sensitivity enhancement

    NASA Astrophysics Data System (ADS)

    Kim, Jae-Ho; Kim, Hyo-Sop; Kim, Jin-Ho; Choi, Sung-Wook; Cho, Yong-Jin

    2008-08-01

    A new nano-structured SPR sensor was devised to improve its sensitivity. Nano-scaled silica particles were used as the template to fabricate nano-structure. The surface of the silica particles was modified with thiol group and a single layer of the modified silica particles was attached on the gold or silver thin film using Langmuir-Blodgett (LB) method. Thereafter, gold or silver was coated on the template by an e-beam evaporator. Finally, the nano-structured surface with basin-like shape was obtained after removing the silica particles by sonication. Applying the new developed SPR sensor to a model food of alcoholic beverage, the sensitivities for the gold and silver nano-structured sensors, respectively, had 95% and 126% higher than the conventional one.

  6. The Cost Growth Problem: A Realistic Diagnosis and Solution.

    DTIC Science & Technology

    1983-06-01

    access 30 0~ LJ 0 CD 0 ( 4c CD - V2 0 C.2 ~~CD.------ 0.0 4-J V) 0 0.0 C.,I Cdc = CC, 0 0D C2 =I . 31 haua La OC I- c C _g .- C2 n C2 __. 6.34 LIA ca D...Department Navy Military Personnel Command Washington, D.C. 20370 6. Director for HRM Plans and Policy (OP-IS0) 1 Human Resource Management Division...Washington, D.C. 20301 25. Dana French, CAPT, USN HD HRM Plans & Policy Branch Washington, D.C. 20301 26. Robert Aaron 820 Lamberton Drive Silver

  7. Installation Restoration Program. Phase 2. Confirmation/Quantification. Stage 1. Sites 24-WF15, 25-WF22 and 26-BST5. U.S. Air Force Plant No. 42, Palmdale, California.

    DTIC Science & Technology

    1988-06-15

    Primary Metals: CA Title 2:60 e Arsenic 0.005 mg/L~~ Barium 0.005 mg/LICadmium 0.005 mg/L Chromium 0.01 mg/L Lead 0.05 mg/L Mercury 0.001 mg/L Selenium...analyzed for twelve metals: arsenic (As), barium (Ba), cadmium (Ca), chromium (COr), lead (Pb), mer- cury (Hg), selenium (Se), silver (Ag), iron (Fe...Total Threshold Limit Substnce (mg/L) (mg/Kg) Arsenic 5.0 500 Barium (excludingf barium sulfate) 100 10,000 Cadmium 1.0 100 Chromium VI 5 500 Chromium

  8. 40 CFR 421.126 - Pretreatment standards for new sources.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... following values: (a) Subpart L—Film Stripping. PSNS Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/troy ounce of silver from film stripping Copper 64.450 30.720 Zinc 51.360 21.150 Ammonia (as N) 6,712.000 2,951.000 (b) Subpart L—Film Stripping Wet Air Pollution Control and...

  9. Removal of Lead Hydroxides Complexes from Solutions Formed in Silver/Gold: Cyanidation Process

    NASA Astrophysics Data System (ADS)

    Parga, José R.; Martinez, Raul Flores; Moreno, Hector; Gomes, Andrew Jewel; Cocke, David L.

    2014-04-01

    The presence of lead hydroxides in "pregnant cyanide solution" decreases the quality of the Dore obtained in the recovery processes of gold and silver, so it is convenient to remove them. The adsorbent capacity of the low cost cow bone powder was investigated for the removal of lead ions from a solution of lead hydroxide complexes at different initial metal ion concentrations (10 to 50 mg/L), and reaction time. Experiments were carried out in batches. The maximum sorption capacity of lead determined by the Langmuir model was found to be 126.58 mg/g, and the separation factor R L was between 0 and 1, indicating a significant affinity of bone for lead. Experimental data follow pseudo-second order kinetics suggesting chemisorption. It is concluded that cow bone powder can be successfully used for the removal of lead ions, and improves the quality of the silver-gold cyanides precipitate.

  10. Bathymetric Contour Maps for Lakes Surveyed in Iowa in 2006

    USGS Publications Warehouse

    Linhart, S.M.; Lund, K.D.

    2008-01-01

    The U.S. Geological Survey, in cooperation with the Iowa Department of Natural Resources, conducted bathymetric surveys on two lakes in Iowa during 2006 (Little Storm Lake and Silver Lake). The surveys were conducted to provide the Iowa Department of Natural Resources with information for the development of total maximum daily load limits, particularly for estimating sediment load and deposition rates. The bathymetric surveys can provide a baseline for future work on sediment loads and deposition rates for these lakes. Both of the lakes surveyed in 2006 are natural lakes. For Silver Lake, bathymetric data were collected using boat-mounted, differential global positioning system, echo depth-sounding equipment, and computer software. For Little Storm Lake, because of its shallow nature, bathymetric data were collected using manual depth measurements. Data were processed with commercial hydrographic software and exported into a geographic information system for mapping and calculating area and volume. Lake volumes were estimated to be 7,547,000 cubic feet (173 acre-feet) at Little Storm Lake and 126,724,000 cubic feet (2,910 acre-feet) at Silver Lake. Surface areas were estimated to be 4,110,000 square feet (94 acres) at Little Storm Lake and 27,957,000 square feet (640 acres) at Silver Lake.

  11. Cyanidation Study of Slag Rich in Silver

    NASA Astrophysics Data System (ADS)

    Pérez-Labra, Miguel; Romero-Serrano, J. Antonio; Ávila-Davila, E. O.; Reyes-Pérez, M.; Barrientos-Hernández, F. R.; Hernández, I. A. Lira

    Slag from smelting reduction processes were characterized by chemical analysis, XRD, SEM-EDS and XRF. The results revealed Ag concentrations of 362 g/t of slag, the slag mineralogical characterization by XRD and SEM-EDS showed mineralogical species oxidized complex containing Pb, Zn, Ca, Si, Fe, As, S in its structure, silver was found in globules associated lead in the slag and the furutobeite specie. The leaching study was conducted to evaluate process variables such as NaCN concentration: from 7.8×10-3M - 1.26×10-1M, temperature: 25-50°C, particle size: +140 mesh to -400 mesh, stirring speed of 750 rpm - 900 rpm. All studies were performed with a NaOH concentration of 0.2 M. The optimal values of silver recovery encountered in conditions of 7.8×10-3M NaCN, agitation rate of 750 rpm, temperature of 35°C and with a treatment time of 240 min. We also observed that a particle size -400 mesh will have optimum recoveries compared to +140 mesh, +200, +270 and +325.

  12. Comparative trial of octyl-cyanoacrylate and silver sulfadiazine for the treatment of full-thickness skin wounds.

    PubMed

    Singer, A J; Berrutti, L; McClain, S A

    1999-01-01

    A prospective, randomized, blinded, controlled experimental trial was performed in pigs to compare the rates of reepithelialization of 126 full-thickness cutaneous 4-mm punches treated with an octyl-cyanoacrylate spray, silver sulfadiazine, or a dry gauze (controls). Full thickness biopsies were taken 7, 14, or 30 days later for histopathological evaluation of hematoxylin and eosin stained tissue sections by a dermatopathologist. The primary outcome measure was the proportion of wounds completely re-epithelialized at days 7 and 14. Secondary outcomes were the rates of infection, foreign body reactions, and the depth of any resulting cutaneous dells measured with a micrometer. Between-group comparisons were performed with ANOVA or Chi-square tests. Octyl-cyanoacrylate treated wounds re-epithelialized more slowly, as fewer wounds treated with octyl-cyanoacrylate were re-epithelialized at day 7 in comparison with silver sulfadiazine or control wounds (50% vs. 90% vs. 100%, p < 0.001). There were no infections or foreign body type reactions. Amounts of granulation tissue were similar among groups. Octyl-cyanoacrylate wounds were more depressed than silver sulfadiazine wounds at days 7 and 14 yet had similar histopathological characteristics at day 30. We conclude that treatment of small, full thickness cutaneous wounds with octyl-cyanoacrylate results in delayed re-epithelialization and dermal repair in comparison with silver sulfadiazine, yet it does not result in any foreign body-type reaction. However, by 30 days, histopathological wound characteristics were similar in all groups.

  13. Luminescence properties of erbium doped sodium barium borate glass with silver nanoparticles

    NASA Astrophysics Data System (ADS)

    Rajeshree Patwari, D.; Eraiah, B.

    2018-02-01

    Alteration in the absorption features of rare earth (RE) doped glasses with silver nanoparticles is ever-challenging in photonics. Erbium (Er3+) doped glasses with composition (60-x-y)B2O3-30Na2CO3-10BaO-xEr2O3-yAgCl where (x=0.5, 1.0 and y=1.0 mol %) are synthesized using melt-quenching method. The density is determined by Archimedes principle and molar volumes are calculated. Glass samples were characterized by XRD and UV-Visible spectroscopy. UV-Visible spectra shows eleven prominent absorption peaks centred around 366, 378, 408, 442, 452, 489, 521, 547, 652, 800 and 977 nm equivalent to the rare earth (Er3+) ion transitions. The sample without rare earth shows no peaks which specifies that rare earth ion plays a spirited role in the glass matrix. The glass samples with silver and without rare earth ion shows plasmon peak on heat treatment. The energy band gap values calculated for direct and indirect transitions are in the range of 3.126-3.440eV and 2.58-3.177eV respectively. The refractive indices and Urbach energies are also determined. Photoluminescence spectra are recorded and studied for excitation of the most intense peaks of wavelengths 378 and 521nm. The luminescence of erbium ion is enhanced by the presence of silver when the concentration of rare earth ion is less than that of silver.

  14. Indirect spectrophotometric determination of trace cyanide with cationic porphyrins.

    PubMed

    Ishii, H; Kohata, K

    1991-05-01

    Three highly sensitive methods for the determination of cyanide have been developed, based on the fact that the complexation of silver ions with three cationic porphyrins, 5,10,15,20-tetrakis-(1-methyl-2-pyridinio)porphine [T(2-MPy)P], 5,10,15,20-tetrakis(1-methyl-3-pyridinio)porphine [T(3-MPy)P] and 5,10,15,20-tetrakis(1-methyl-4-pyridinio)porphine [T(4-MPy)P], in alkaline media is inhibited by cyanide and the decrease in absorbance of the silver(II) complex is proportional to the cyanide concentration. Sensitivities of the procedures developed are 0.133, 0.126 and 0.234 ng/cm(2), respectively for an absorbance of 0.001. Cadmium(II), copper(II), mercury(II), zinc(II), iodide and sulfide interfere with the cyanide determination. One of the proposed methods was applied to the determination of cyanide in waste-water samples, with satisfactory results.

  15. Phyto-assisted synthesis of bio-functionalised silver nanoparticles and their potential anti-oxidant, anti-microbial and wound healing activities.

    PubMed

    Mohanta, Yugal Kishore; Biswas, Kunal; Panda, Sujogya Kumar; Bandyopadhyay, Jaya; De, Debashis; Jayabalan, Rasu; Bastia, Akshaya Kumar; Mohanta, Tapan Kumar

    2017-12-01

    Bio- synthesis of silver nanoparticles (AgNPs) was made by using the aqueous leaf extract of Ardisia solanacea. Rapid formation of AgNPs was observed from silver nitrate upon treatment with the aqueous extract of A. solanacea leaf. The formation and stability of the AgNPs in the colloidal solution were monitored by UV-visible spectrophotometer. The mean particle diameter of AgNPs was calculated from the DLS with an average size ∼4 nm and ∼65 nm. ATR-FTIR spectroscopy confirmed the presence of alcohols, aldehydes, flavonoids, phenols and nitro compounds in the leaf which act as the stabilizing agent. Antimicrobial activity of the synthesized AgNPs was performed using agar well diffusion and broth dilution method against the Gram-positive and Gram-negative bacteria. Further, robust anti-oxidative potential was evaluated by DPPH assay. The highest antimicrobial activity of synthesized AgNPs was found against Pseudomonas aeruginosa (28.2 ± 0.52 mm) whereas moderate activity was found against Bacillus subtilis (16.1 ± 0.76), Candida kruseii (13.0 ± 1.0), and Trichophyton mentagrophytes (12.6 ± 1.52). Moreover, the potential wound healing activity was observed against the BJ-5Ta normal fibroblast cell line. Current research revealed that A. solanacea was found to be a suitable source for the green synthesis of silver nanoparticles.

  16. The tobacco mosaic virus RNA polymerase complex contains a plant protein related to the RNA-binding subunit of yeast eIF-3.

    PubMed Central

    Osman, T A; Buck, K W

    1997-01-01

    A sucrose density gradient-purified, membrane-bound tobacco mosaic virus (tomato strain L) (TMV-L) RNA polymerase containing endogenous RNA template was efficiently solubilized with sodium taurodeoxycholate. Solubilization resulted in an increase in the synthesis of positive-strand, 6.4-kb genome-length single-stranded RNA (ssRNA) and a decrease in the production of 6.4-kbp double-stranded RNA (dsRNA) to levels close to the limits of detection. The solubilized TMV-L RNA polymerase was purified by chromatography on columns of DEAE-Bio-Gel and High Q. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and silver staining showed that purified RNA polymerase preparations consistently contained proteins with molecular masses of 183, 126, 56, 54, and 50 kDa, which were not found in equivalent material from healthy plants. Western blotting showed that the two largest of these proteins are the TMV-L-encoded 183- and 126-kDa replication proteins and that the 56-kDa protein is related to the 54.6-kDa GCD10 protein, the RNA-binding subunit of yeast eIF-3. The 126-, 183-, and 56-kDa proteins were coimmunoaffinity selected by antibodies against the TMV-L 126-kDa protein and by antibodies against the GCD10 protein. Antibody-linked polymerase assays showed that active TMV-L RNA polymerase bound to antibodies against the TMV-L 126-kDa protein and to antibodies against the GCD10 protein. Synthesis of genome-length ssRNA and dsRNA by a template-dependent, membrane-bound RNA polymerase was inhibited by antibodies against the GCD10 protein, and this inhibition was reversed by prior addition of GCD10 protein. PMID:9223501

  17. Improving Healthcare Facility Locations in Bamyan, Afghanistan

    DTIC Science & Technology

    2011-12-01

    WU~U n ~~~=u=~~~~~~~~==~~~~~~~~u~~~~~~m~~~u ~ n~~=~~~=~=u~~=~=~ ~~~~~=~~~==~~~~-~~~~~~-~~=~~•==~~~~ uuu u~u~eas •w~M~~~~~M~ w ~~~~m...su 3~u==~~~~~u~~~~~= ® ~~~~u~~~-~~~~~~~~~~~~~==~=~~==~n~=~~n~ uuu ~~~=~~m~~~~u~ o ~~~~=~~-~~~=~~~~~~~~~w~~~=~•~=~~~~~~~u~u...u •uan=•~~~~~·~ u ==~-~~~~~-~~~~~~~~=~~~~~~~~~-=~~~~=~~~ uuu uu~~~~=~~~~=~v u ~~~~~~~~~~~~~~~~~~~~~u~~==~n=~~~~~~=~e~~•u mn~~a=~~~~•= M

  18. Contracting Strategy for Navy Missile Acquisitions.

    DTIC Science & Technology

    1977-11-09

    PROJ ECT , TASK AREA S WORK UNIT NUMBERS DEFENSE SYSTEMS MANAGEMENT COLLEGE FT. BELVOIR, VA 22060 II. CONTROLLING OFFICE NAME AND ADDRESS 12 . REPORT...technical 12 LL~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~ -. -— . •—_ ~~~~~~~~~~ .~~~~~~~~~~~~ .~~~ evaluation, contractor monitoring...you want o Clear cost advantage if valid data exists o Establishes a dedicated military / industria l team with one basic purpose o More timely respon

  19. Will Japan Rearm.

    DTIC Science & Technology

    1977-06-10

    Faculty Accepte d th is _________ day of~~~U)~4 l977~c~y.11 -~~~~~~~~~~~~D i rector , Master of Militar y Art Science . The opinions and...j~ s’ri : ‘~~~~ ~ IC . _ __~~~~~~ i 1~~~~~n Unhi ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 150 _ _ _ _ _ _ _ _ _ _ L~ MASTER OF MILITARY ART ... SCIENCE THESIS APPROVAL PAGE Name of Candidate Joseph Bertrand Berger, Jr. Major, Air Defense Artillery T it le of Thes i s W i l l Japan Rearm

  20. Summary of Meteorological Observations, Surface (SMOS) Pensacola, Florida.

    DTIC Science & Technology

    1978-07-01

    flSV~MAYN IC’~4~ ~~~ ) ‘) .) ‘ - J IISPS -LS0I 151,1 I — — — _ — ________— — — -~~ -~~ ~~~~~~~~~~~~~~~~~~~~ -, I F~~~ ’ ~~~~~~~~~~~ —~~ . ~~ J-~4S

  1. Parent-Flare Emission at 2.8 GHz as a Predictor of the Peak Absorption of Polar-Cap Events.

    DTIC Science & Technology

    1976-12-01

    Technical Report 20 15 ( TR 20 15) ____________________________ i n ~~~~~~~~~~~ o ~~~~ - - S TAPE OF 9EPçJ~~~ & Pf RIOO C O V E R E O ~~‘ J~ARENT...i11 ( , is iehl i , WR lt , t u 1 , . 11 , tr id I \\ .ii ~~~~~ I 07 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ l ’ABLF I - RF\\ ’l I :W 01: Ml...1 1 ,0 C) 10 > ~t tas I” 1154$ 313 N2S .W32 ,55~ 5 0 ISO 4 N 0$ N1 I ’. (17 USSr ’ 213 St S .W02 ‘1047 I 000 0.’) N~ I I 0’) Lii i (~S t) S54 313

  2. Some Problems of Queues with Feedback.

    DTIC Science & Technology

    1978-11-01

    occur in comr,uter networks , production networks, Street traffic networks , neural networks , and the like . In spite of these potential applications...55— - - - ~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~ 29 b where h — ~ j ~ . Now, caking the Lap lace —Stieltjes transform of the above k

  3. A Low Cost Navigation Microprocessor System.

    DTIC Science & Technology

    1977-03-01

    a., 77843. uaed to iteratively update hi ~~~~~~~~~ -~~~- .:S~~~~~~~~~~~~~ . .— a — ~~~~~~~~~. - ~~~~ - . .- . — --- •5 n- -pr~~~ I~~~ ‘77 PIC ~~DU...the altitude above the reference ellipsoid (Ian — feature is implemented as step (6) below . nude —longitude—altitude coordinate system). Since cal

  4. Shipping Containers as Structural Systems.

    DTIC Science & Technology

    1977-07-01

    hi moms ’ ef for t to r - ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ — --- :~~~~~~~~~~~~ - ‘ - - —--_ _ _ _ iui:iittt: lut i :u h i ur mmu u i e tm h...t hus ’ n e hi m i_ I beett imo sits ’ im ui p rt us’s’ tile mit i_’it huer hei rs’ or i_ ht u ni m m , t ime field t e s ts , l’x pedi eu tt r u m

  5. A Case Study On Pile Relaxation In Dilative Silts

    DTIC Science & Technology

    2011-12-20

    HHH +~H+~~++~~ r losr-~~~~~~~~~~~~H 21~~~~~~~~~~~~~ ~HH~~~~++~~~~44~ ~110~~~~~~~~~~~~~~ 22HHHH~--HHHH44~44444444~ r-H4+++H...i ne gravel, trace of clay, medium dense , wet. SILT, grey, and fine sand, medium stiff, non plastic, wet. -HH++ HHH +~H4~~++HH4 f- 45 1 01-H-HH-1...rHH++HH4~HH4 8HH+rH+.rH++HH+~H++H -HH++ HHH ++HH+~HH++HH4 --40~++HH~+HH+~HH++HH~ 9H+~H++HH++HH+rHH+~ --HH++~~rHH++HH4++HH4 _ srq-+H~~H++H4+HH4

  6. Participative Budgeting as a Communication Process: A Model and Experiment.

    DTIC Science & Technology

    1978-01-01

    Control Group Design Methodology Setting Condition Measurements Summary :, ~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~ - -a...criticized the experimental design at length , particularly the experimental variat ion of the control dimension. In his view , Ti the in terpreta t ion of...Thus, th is approach is adopted to avoid the poss ihi lir- -- of th e testing effect. The P o s t — T e s t Cr1 -- , Control Group Design -\\mong the

  7. Surface Phonons and Polaritons.

    DTIC Science & Technology

    1976-01-01

    by M. Balkaneki ( Flammarion Sciences , Paris , 1978) , p. 298 . —-——.——~~~~~~~~‘-,--—-—— - r r ~~~~~~~~~~~~~~ ~~-~r - wwr~~~~~~~~~~~ wr...inivasan, in Lattice Dynamics Edited by K. -~ Balkanski ( Flammarion Sciences , Paris , 1978), p. 305. 46. I. K. Lifshitz and L. U. Rosenzweig , Zh. Ekap...Lattice Dynamics,” Ed. M. Balkanski ( Flammarion Sciences, Paris, 1978), p. 280. 7. L. Dobrzynski and J . Friedel, Surface Sc 12, 469 (1968). 8. L

  8. Metallurgical Changes in the High Temperature Fretting of Ni and Ti Alloys.

    DTIC Science & Technology

    1976-10-01

    a layerstructure on the surface. DO , ~~~~~~~~~~~ 1473 porno .. OP V ~~v ss is o soi..ETE - ; •ECVAITY CLAUIF1CATIOf, Or ThiS PAGE (Nba. D.ta —a-~~S~?~~~~~~~w3 ~~~~~~ Y~*.S 4- - ~~ %..flCt

  9. U.S. EPA, Pesticide Product Label, GLY N GO, 05/11/2009

    EPA Pesticide Factsheets

    2011-04-21

    ... TREE, VINE, AND SHRUB CROPS (Alphabetical) ! ~I~~~~ T~kSE~~~i~~~ ~~VDE~~~~~Rt~~~~E~~~~:E6H~~pA::i~TT2A~C~ BELOW. ...

  10. VizieR Online Data Catalog: OCARS catalog second version (Malkin, 2016)

    NASA Astrophysics Data System (ADS)

    Malkin, Z. M.

    2016-11-01

    Unlike the first version, supported in 2007-2015, the second version of the OCARS catalog includes three files: ocars.txt is the main file containing the source coordinates, source types, redshifts, and approximate magnitudes, together with commentary; this file corresponds to the first version of the OCARS catalog; ocars_m.txt contains photometric data in the 13 uUBgV rRiIzJHK bands; ocars_n.txt contains a table of corresponding source names in various catalogs; currently, only cross-identifications with IVS programs4 and the LQAC catalog [9] are included; The list of objects included in the OCARS catalog is formed from various astrometric and geodeticVLBI programs and catalogs in the following order: - sources in the ICRF2 [2]; - other sources observed in the framework of IVS programs; - sources from the NASA Goddard VLBI group catalog5 ; - sources from the RFC catalog,6 which is the most complete astrometric catalog of radio sources, is updated each quarter, and contributed more than half the OCARS objects; the latest version of OCARS used the RFC-2016a catalog based on observations obtained in 1980-2015 as part of IVS and other radio astrometric programs [19-31]; - sources from the literature. Optical Characteristics of Astrometric Radio Sources (OCARS) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Last revised: 27-NOV-2016 Latest update: - removed 30+ RFC sources not identified in NED and optics - removed rather long detailed statistics table, which seems to be not interested for most of users; it is always available on request - a few additions and amendments E-mail alerts about updates are available on request. URL of this file is http://www.gao.spb.ru/english/as/ac_vlbi/ocars.txt Supplement files: Optical and IR magnitudes: http://www.gao.spb.ru/english/as/acvlbi/ocarsm.txt Cross-identification table: http://www.gao.spb.ru/english/as/acvlbi/ocarsn.txt OCARS catalog in CSV format: http://www.gao.spb.ru/english/as/ac_vlbi/ocars.csv Please send comments and requests to Zinovy Malkin, malkin(at)gao.spb.ru ---------------------------------------------------------------------------- The Second Version of the OCARS Catalog of Optical Characteristics of Astrometric Radio Sources. Astronomy Reports, 2016, Vol. 60, No. 11, pp. 996-1005. DOI: 10.1134/S1063772916110032 If you use OCARS catalog in your work, please cite this publication. ---------------------------------------------------------------------- Brief OCARS statistics (detailed statistics is available on request) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Total number of sources 11375 +30...+90 3320 ( 29.2%) -30...+30 6233 ( 54.8%) -90...-30 1822 ( 16.0%) Number of sources with known type 6284 ( 55.2%) AGN 4704 ( 74.9%) quasars 3027 ( 64.3%) BL Lac 992 ( 21.1%) Seyfert 384 ( 8.2%) blazars 89 ( 1.9%) radio galaxies 1580 ( 25.1%) Number of sources with redshift info 5845 ( 51.4%) +30...+90 1803 ( 30.8%) -30...+30 3329 ( 57.0%) -90...-30 713 ( 12.2%) unreliable 868 ( 14.9%) Number of sources with known magnitude 8133 ( 71.5%) +30...+90 2380 ( 29.3%) -30...+30 4481 ( 55.1%) -90...-30 1272 ( 15.6%) Number of sources with both z and magnitude info 5803 ( 51.0%) (3 data files).

  11. U.S. EPA, Pesticide Product Label, CORNERSTONE PLUS, 12/12/2007

    EPA Pesticide Factsheets

    2011-04-14

    ... l:rn~%~if;l~.iJ.~91~:~f}1~~~~~i}~>~~f*~~lt\\~~1j%i;if~:11~~:~!5t~ft;K!~~1j~:~~\\ g1~~g~:if1§~111g1;~~l~~?1~~l~it2t~1!~l:Vi~~§1.~~~ Annada, spurred ...

  12. The Electrical Conductivity of Li2SO4: LiBr: 0.07 K2SO4.

    DTIC Science & Technology

    1978-09-01

    1ca , R SUM On a synthétlaë un electrolyte solide ~ base de sulfate de lithium en combinant du bromure de lithium et du sulfate de potassium; il...UNCLASSI?I~~ - —~ —. - ~~~~~~~~~~~~~~~~~~~~~~~~~~ .--._ .. ~~~~~~~~~ .. 2 UN~LASSIPI~) Lithium salts, on the other hand , are not only less costly...but they also yield terminal voltages >2 V in certain electroch.mical cells. On . of the earliest lithium compounds to be invest igated i. LiI which has

  13. U.S. EPA, Pesticide Product Label, FLEAGO THE MAGIC CRYSTAL, 07/09/1997

    EPA Pesticide Factsheets

    2011-04-21

    ... Fleago The Magic Crystal '~~~:ul~~i~;~i~~!;~i~~fat~~I~~n~w~~~~: W~?~:~iA~~~~~r~Y '~~;: ... lhe Magic Crystal ...

  14. Satellite Atmospheric Radiance Measurements in the Vacuum Ultraviolet.

    DTIC Science & Technology

    1979-07-05

    APERTURE I I 1_ _~~J ;~- WHEEL MOTOR IDRIVE r~~ II I :_-~I ~~~~~~~~~~~~~~~~~~ ~~~_I ~~APERT URE WHEEL\\ ELLIPSOIDAL PRIMARY MIRROR VV ~ V SUNSHADE V I...Table 1. Vacuum Ultraviolet Backg rounds Sensors (Cont ) P~ iot ometer Interf erence Filters (A) 1216 1340 1550 1750 no f

  15. Mildenhall RAF, United Kingdom Revised Uniform Summary of Surface Weather Observations (RUSSWO). Parts A-F.

    DTIC Science & Technology

    1984-04-01

    III*.d) REDISRCIN REPORT DOCUMENTATION PAGE BFRED COMTPLETINORM 1REPORT NUMBE 5 . OVT ACCESSION NO, S. RECIPIENT’S CATALOG NUMBER USAFETAC/DS -84/016...930at 3~~~~~~~~~~~~~~~~~~~~~~ -A------.------.---.-------.----- - - - - - - - - - -__ CJ- .1~ ~~~~ -1----------- F .. ........ 4 w.wI 1 . . SS7 G

  16. Electrochemical Studies of Atmospheric Corrosion.

    DTIC Science & Technology

    1979-01-01

    d -. vi ~~ ‘ ~~~~~~~~~~~~~~~~~~~ Director , Metallurgy Programs Material Sciences Div is ion Office of Naval Research 7~ - ~~800 North Quincy...STATEMENT (of At . R.porE) Approved for Public Re l ease; distribution unlimited ‘7. OISTRISUTION STATEMENT (of A. .b.’t.c( ent.,. d lie Block 20. II...t Unclassified 20 ~~~~~~~~ C~ AUIPICAYION OP Tifil PAO*(IThoi D . S~loi.d) ‘from polarization resistance measurements using the CORFIT computer

  17. Ion Implantation of Wide Bandgap Semiconductors.

    DTIC Science & Technology

    1978-05-01

    VIflbJ DAI’C lEAD INSTRUCTIONS ~~~~~~~~~~~ 1 ~~~~~~~~~~~~~~~ ~~ “I ~~~~~~ BEFORE CONPLETING PORN I. mEPO~~T NUMUIR 3. GOVT...bs?,e, f ~nte,ed ,n l3b.~ k .~‘O . , V diII.,ent 1,...,. H.po,t~ IS. SUP PLEMENTARY NOTES t~ . KEY WORDS (ConIInu. on c.,.,.. old . II ni.r ~~,to...From two semi — In st i l at log subst ‘~~t t (‘S i mp l a n t e d wit ft S x 10 16 cm 2 1 01) keV S and ann ea led :it 8()0°( I or 30 m i i i 1

  18. Highlights of L011.

    DTIC Science & Technology

    1977-08-03

    AD—A OQ 15 CALIFORNIA UN I V SANTA CRUZ INFORMATION SCIENCES FIG 9.’2 HIGHLIGHTS OF LO11.(U) ~~~ LASS ~~~~~ TR— 77—8—OO5 H MCKEEMAN EN D...EA & WORK UNIT NUMBERS Board of Studies in Information Sciences - . University of Californiav ~~~~~~~~ • I Santa Cruz, Ca1ifnrn(~ 9S~ f LL - II. C O...Office of Naval Research contract NOOO1~ —76 C O682.* .~~~~ .. 3. The Board of Studies in InforMation Sciences, UCSCe~~~~ ~~~~~ 00 ~~ ~~~~~ ifl ,’jIIfl

  19. U.S. EPA, Pesticides, Label, DIXICHLOR MAX, 2/28/2011

    EPA Pesticide Factsheets

    2011-04-13

    ... ri~~a!!:it~$e a cr!~~n~t. bb:~~rtre;~t~~ p~~ ~;:II t~~ a~~li~rib~: ... g~~'!~e~fdi~:a::r~~3'e:~~oP~~~r:~tt~mina!e food or feed ...

  20. U.S. EPA, Pesticide Product Label, UNICORN MULTI-PURPOSE HOUSE & GARDEN INSECT KILLER, 11/06/1996

    EPA Pesticide Factsheets

    2011-04-21

    ) f=;:==U~'S~'~O~~~:~i~~~~O~~~f;l~p~~·~~e~i~~~~~e~~; r~~0J~~ams~At~G;:~cY~q==3==-1~::'~ fD ...

  1. Specific Air Pollutants from Munitions Processing and Their Atmospheric Behavior. Volume 3. TNT Production.

    DTIC Science & Technology

    1978-01-01

    o-t / \\ ~~~~~~~~~~~~~~~ / uL~~~~~~ > \\ ) F L O Y D co / - : ~~~~~~~ FLOY D / \\.C -\\ ‘ 221 \\ J 0 5 10 \\ .1 ASCALE IN MIL ES . \\. r...through the blower. In the primary catch tank , gravity separation allows some of the water to be returned to the venturi scrubber. The remaining pink

  2. Topical Hazard Evaluation of Candidate Insect Repellent AI3-36539, 1-(Cyclohexylcarbonyl)-2-Ethylipiperidine.

    DTIC Science & Technology

    1977-05-12

    form and concentration I~ tended for usage. PORN - - $ ,, ~~ ~~ 1413 ( OnION OF I NOV 555 OBSOLETE clasaif ~ed _____ -~~ -~~~~~~~~~•-~~~~-- -~~ ‘~i

  3. Error Detection in Computerized Information Retrieval Data Bases,

    DTIC Science & Technology

    1977-07-01

    published in London , England? Can citing authors be depended upon to give the full title to journals to avoid confusing Library Science and Documentation...published in New York with Library Science ~ with a slant to 11 ~~~~~~~~~~~~~~~~~ ~• r:-~~~~~~~ . r

  4. Turbine Engine Variable Cycle Selection Program Summary.

    DTIC Science & Technology

    1977-04-01

    en Dee. Entered) 1 , ~~~~~~~~ DOCUMENTATION PAGE BEFORE COMPLETING F 4~ 4 I. ~~~~~~~~~~~~~~~~~~~~~ 2 . GOVT ACCESSION NO. 3- ~$ 1 .~~IENT ’S CATALOG...CONT ENTS SECTION PAGE 1 . INTRODUCTION 1 2 . PROGRAM APPROACH 2 3. FIGHTER ENGINE/AIRFRAME EVALUATION PROCEDURE 8 3.1 Input 9 3.2 Computation 9 3.3...Range of !‘:!~ nme t ric Mission ~)ash V a 1 ~1es 7 28 T5 ar a ~n ct r ic Eng ine C’ 1 — L r a c t o r i s t i c s 28 2 9 Thrust Lapse Comparisons 2

  5. Maximizing Efficiency and Effectiveness of Information Data Banks,

    DTIC Science & Technology

    1977-05-01

    I n . ’ p cc :‘ i I c , I ’ 1m , ,’ ’ , n , r , or, I total coSts ~~:‘ ‘, h~ igb ; ,j ’~~” Oil ’1 U t u ’ n , ‘os.’d j r,:’,-r’n-’,’ut , n. .‘cu...Su~l iJi, ,’ l um p ,,’ c ‘‘ I ’ Luv ’ r id Si , 5I.mr~ I r n Ru’s k 1a smk Or i ’lll ult ’’tl K e n t R R o ~ 3R 1- I ‘ s I l l - I ) SI - S T I ...kiiL~ _ .1!a ~1 I I ( AGARD-R-657 LAtGA~R1D~1 ~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~ ~ i ~~ i :~~,j

  6. Sequential Medical Trials Involving Paired Data.

    DTIC Science & Technology

    1979-05-22

    and A. John Petkau Depar~~~nt of MathematicsUniversity of British Columbia I Accession For N?IS GRiA-&I DDC TAB Una~mounced - Justification...John Petkau Department of Mathematics University of British Columbia SUMMARY A continuous time version of Anscombe ’ s formulation of the problem of...AIlS 1970 subject classifications : Primary 62Ll0; secondary 62C10, 62Ll5. — — -- m.~~, -- -~ —— - -- ~~~~~~~~ ~~~~~~~~~~~~ 1. INTRODUCTION A natural

  7. High Contrast CRT.

    DTIC Science & Technology

    1979-08-01

    2800 Powder %lil l Road 2595 Yeager Road 001 Adelphi . Ml) 20783 001 W . Lafayet te , IN 47096 6 17 C D X . ER A D CO M 701 MI T - Lincoln Labora...TI ~~~~~~~~~~~ .ati.C.s,*.1 I*O O aI I Iv O aft. .... ~~~~~~~~~~~~~~~ ‘1 $ 1 C o ~ø”? C ,. *1I (•0 ‘I. ~~~~~~~ I “ ( I A ” I I IF D ‘a. ~r: as% ,a, c ...at lo~ bea m cue rg it ’ s , n I’, the red Ih i Is p hi ‘r is t’~~ c ited and the d lspiav appears re~t , At h igh 1 lea in ene rg I t s , th~’ g

  8. RISDON AMS CORP, REMEDIAL ACTION PLAN COMPLETION REPORT ON PROPERTY CONDITIONS, 06-19-2009, RDMS# 107113

    EPA Pesticide Factsheets

    2012-06-07

    ... metals at two Thi~~~~6W6lo~~~~~at I, Assembly and I ric ~~i~~,SYd~~~~m~~ sick days, holidays, or online at :a ... Objections must I Bethel Learning ...

  9. U.S. EPA, Pesticides, Label, DITHIOPYR 0.172 PLUS, 7/10/2009

    EPA Pesticide Factsheets

    2011-04-13

    ... MS. NC, se, TX Crowfootgrass. ... V::~:;esi:o~~:~~t~~:~~t~s::~w~oison ;::::lyrfc~~~;~et~:b= ~~ ~s:::,,ds:: :: :gO~~f6~~ (~; ...

  10. Suitability of Lake Erie for bigheaded carps based on bioenergetic models and remote sensing

    USGS Publications Warehouse

    Anderson, Karl R.; Chapman, Duane C.; Wynne, Timothy; Masagounder, Karthik; Paukert, Craig P.

    2015-01-01

    Algal blooms in the Great Lakes are a potential food source for silver carp (Hypophthalmichthys molitrix) and bighead carp (H. nobilis; together bigheaded carps). Understanding these blooms thus plays an important role in understanding the invasion potential of bigheaded carps. We used remote sensing imagery, temperatures, and improved species specific bioenergetics models to determine algal concentrations sufficient for adult bigheaded carps. Depending on water temperature we found that bigheaded carp require between 2 and 7 μg/L chlorophyll or between 0.3 and 1.26 × 105cells/mL Microcystis to maintain body weight. Algal concentrations in the western basin and shoreline were found to be commonly several times greater than the concentrations required for weight maintenance. The remote sensing images show that area of sufficient algal foods commonly encompassed several hundred square kilometers to several thousands of square kilometers when blooms form. From 2002 to 2011, mean algal concentrations increased 273%–411%. This indicates Lake Erie provides increasingly adequate planktonic algal food for bigheaded carps. The water temperatures and algal concentrations detected in Lake Erie from 2008 to 2012 support positive growth rates such that a 4 kg silver carp could gain between 19 and 57% of its body weight in a year. A 5 kg bighead carp modeled at the same water temperatures could gain 20–81% of their body weight in the same period. The remote sensing imagery and bioenergetic models suggest that bigheaded carps would not be food limited if they invaded Lake Erie.

  11. Auroral Data Analysis.

    DTIC Science & Technology

    1978-01-04

    evaluating Opal, C. B ., W. K . Peterson , and E. C. Beatty, thia paper, Measurement of secondary electron spectra Ref erences produced by electron...Polar Torbet , R. B ., K . A. Anderson, and C. W. cap auroral electron flu xes observed with Carlson, Observations of low and medium Isis 1, 3. Geophys. Res...STATES AIR FORCE HANSCOM AYE , MASSACHUS~~ 2S 01731 B . ~~~~~~~~~~~~~~~~~~~ ~~ — ~ —.-- a Qual ified requestora may obtain additional copies from the

  12. Chemotherapeutic Studies on Schistosomiasis.

    DTIC Science & Technology

    1978-10-01

    sick ’ wor m s posses sing little movement is evidence of possible activity requiring further testing. Untreated control animal s will norma lly show...be re- peated for confirmation . a ;‘~~~~. . t 4 . -.. -...~~~~~~~~~~~~ -.-- .~~ -- L ITE RAT U RE C ITED 1 . Radke , 11. G., Berrios- Duran , L. A

  13. Change in Phagocytic Activity to Tularemia Microbe in Highly Sensitive Animals with Mixed Infection,

    DTIC Science & Technology

    1978-03-17

    neutrophils in the blood of guinea • ‘ pi gs infected with S. typh imurium. — - S ~~~~ OP ~~ ’ ~~ MSt4 ~~P& ~~AJJ~~~~ tl.I-A

  14. U.S. EPA, Pesticide Product Label, , 06/22/1999

    EPA Pesticide Factsheets

    2011-04-21

    ... West Langhorne, PA 19047-3023 ... C])~n'geg" -i- ~ l~be;Ltng di ff ~~J.'rig :,:J; rr:; :~JF~l;:~~~f:f~~::X~~~:(F%~~t~4' ).,ri' :~~~r~ct~~p>,~~,_~:~:: ihf~ : f ...

  15. U.S. EPA, Pesticide Product Label, BIOMIST 30+30 ULV, 05/03/1994

    EPA Pesticide Factsheets

    2011-04-21

    ... m~~I~~~~~3~.5~~~~0~.4~~~~IUD~~.F. 30-30 ULYIIOLYENT DILUTtON RATtO FlIIIglcldo, '" 3O>3D WIth lIght II) plrts lol,ont Ind apply at tho al .... ...

  16. Magnetosheath Effects on Cylindrical Langmuir Probes. Revision

    DTIC Science & Technology

    1979-10-23

    should be noted that Eq. (14) in the work of Bettinger and Walker 16 is in error by a constant. (s2 + 2ps)ln(1 + s ip ) = ir ~/i5(1 + ~ ~p ) 112 should...Ii 1~~~ A9~~Approved (or public release; distribudo. asledled. ~ ‘ / H . , - - ~--~~~ - ~~~ - Best Available Copy S E C U R I T Y CL A O S I F...I C A T I O N OF T H I ’o P A GE ( WN.n 0.1. j REPORT DOCUMENTATION PAGE nEEORF COMPLET!P40 FORM I P~~~~~~~ S~~~~~~~~~~~ __ .—/- - ~2 GOVT a

  17. Synthesis of [{AgO2CCH2OMe(PPh3)}n] and theoretical study of its use in focused electron beam induced deposition

    PubMed Central

    Noll, Julian; Frenzel, Peter; Rüffer, Tobias; Jakob, Alexander; Walfort, Bernhard

    2017-01-01

    The synthesis, chemical and physical properties of [{AgO2CCH2OMe}n] (1) and [{AgO2CCH2OMe(PPh3)}n] (2) are reported. Consecutive reaction of AgNO3 with HO2CCH2OMe gave 1, which upon treatment with PPh3 produced 2. Coordination compound 2 forms a 1D coordination polymer in the solid state as evidenced by single crystal X-ray structure analysis. The coordination geometry at Ag+ is of the [3 + 1] type, whereby the carboxylate anions act as bridging ligands. The formation of PPh3–Ag(I) coordinative bonds results in distorted T-shaped AgPO2 units, which are stabilized further by an additional O–Ag dative bond. TG and TG–MS measurements show that 1 and 2 decompose at 190–250 °C (1) and 260–300 °C (2) via decarboxylation, involving Ag–P (2), C–C and C–O bond cleavages to give elemental silver as confirmed by PXRD studies. In order to verify if polymeric 2 is suitable as a FEBID precursor for silver deposition, its vapor pressure was determined (p 170 °C = 5.318 mbar, ∆H vap = 126.1 kJ mol−1), evincing little volatility. Also EI and ESI mass spectrometric studies were carried out. The dissociation of the silver(I) compound 2 under typical electron-driven FEBID conditions was studied by DFT (B3LYP) calculations on monomeric [AgO2CCH2OMe(PPh3)]. At an energy of the secondary electrons up to 0.8 eV elimination of PPh3 occurs, giving Ag+ and O2CCH2OMe−. Likewise, by release of PPh3 from [AgO2CCH2OMe(PPh3)] the fragment [AgO2CCH2OMe]− is formed from which Ag+ and O2CCH2OMe− is generated, further following the first fragmentation route. However, at 1.3 eV the initial step is decarboxylation giving [AgCH2OMe(PPh3)], followed by Ag–P and Ag–C bond cleavages. PMID:29259876

  18. Synthesis of [{AgO2CCH2OMe(PPh3)} n ] and theoretical study of its use in focused electron beam induced deposition.

    PubMed

    Tamuliene, Jelena; Noll, Julian; Frenzel, Peter; Rüffer, Tobias; Jakob, Alexander; Walfort, Bernhard; Lang, Heinrich

    2017-01-01

    The synthesis, chemical and physical properties of [{AgO 2 CCH 2 OMe} n ] ( 1 ) and [{AgO 2 CCH 2 OMe(PPh 3 )} n ] ( 2 ) are reported. Consecutive reaction of AgNO 3 with HO 2 CCH 2 OMe gave 1 , which upon treatment with PPh 3 produced 2 . Coordination compound 2 forms a 1D coordination polymer in the solid state as evidenced by single crystal X-ray structure analysis. The coordination geometry at Ag + is of the [3 + 1] type, whereby the carboxylate anions act as bridging ligands. The formation of PPh 3 -Ag(I) coordinative bonds results in distorted T-shaped AgPO 2 units, which are stabilized further by an additional O-Ag dative bond. TG and TG-MS measurements show that 1 and 2 decompose at 190-250 °C ( 1 ) and 260-300 °C ( 2 ) via decarboxylation, involving Ag-P ( 2 ), C-C and C-O bond cleavages to give elemental silver as confirmed by PXRD studies. In order to verify if polymeric 2 is suitable as a FEBID precursor for silver deposition, its vapor pressure was determined ( p 170 °C = 5.318 mbar, ∆H vap = 126.1 kJ mol -1 ), evincing little volatility. Also EI and ESI mass spectrometric studies were carried out. The dissociation of the silver(I) compound 2 under typical electron-driven FEBID conditions was studied by DFT (B3LYP) calculations on monomeric [AgO 2 CCH 2 OMe(PPh 3 )]. At an energy of the secondary electrons up to 0.8 eV elimination of PPh 3 occurs, giving Ag + and O 2 CCH 2 OMe - . Likewise, by release of PPh 3 from [AgO 2 CCH 2 OMe(PPh 3 )] the fragment [AgO 2 CCH 2 OMe] - is formed from which Ag + and O 2 CCH 2 OMe - is generated, further following the first fragmentation route. However, at 1.3 eV the initial step is decarboxylation giving [AgCH 2 OMe(PPh 3 )], followed by Ag-P and Ag-C bond cleavages.

  19. Data & Analysis Center for Software.

    DTIC Science & Technology

    1986-11-01

    DA~~~~~~~~~~~~~.~~df anACIIIAP.fre ua yn AASfwr 2nene3n maorul s. tod croltlf cyota eee abor thsAcN i PUA09L CAIWT OmT caDUe byID am~ Uliawledega if

  20. Fuel Cell Introduction into a Class 8 Truck

    DTIC Science & Technology

    2003-09-11

    compressor in Its efficient zones, and packeging . lJhile __ l_ooki_flg __ l~~--reP.I~c!ll9_the _ _9_E_...__~~~~!1~~~~-!i.riV.~!’l.~~P.t:e~~--~!f:l

  1. Facsimile: An Overview for the Manager. Executive Summary.

    DTIC Science & Technology

    1973-05-01

    block nia,b.r) SEE ATTACHED SHEET N~ A~~~~~AC? f’ ~~~ Id~~ lfr by block m b.r) SEE ATTACHED SHEET ,‘.~~~~ 1Q3 EMPTIOSI OV ~ ~~ s ~ OS~~ _f’T~E . - S...1 vi I I ~‘~A (•’,, I~~I A~; o p :~~Tfl~w FOR : Td , MA1~~:;I~RI ii. od uct ior : In l~ 38 . A. N . Go~.ds m i t h c . n c l od~ d t~~at te le i... TD ~ The ident ical costs l imits shown occur because the ’ I same eam ipm en t may be built to operate at several fk’- r en t speeds simply by se t

  2. NEW BEDFORD, EMAIL REGARDING NEW BEDFORD HARBOR - DESIGN MEMORANDUMS 2 & 5 (MEMOS ATTACHED) - STATE ENHANCED REMEDY (SER), 08-21-2012, SDMS# 526371

    EPA Pesticide Factsheets

    2013-06-11

    ... The gates consist of two similar leaves .with radii of 90 feet and overall height of 61 feet. ... I ~~~~~o~~~~~de~~~~~e:h~~h a beveled ...

  3. U.S. EPA, Pesticide Product Label, TOUGH STAIN REMOVING INSTITUTIONAL COMET CLEANSER WITH CHLORINOL G, 02/10/1975

    EPA Pesticide Factsheets

    2011-04-21

    ... 1i~~~~~M~T"~C~H~~~~R~I~NO~L~~O~~~~~iil i _L~=_===7 USE COMET ~ ~ FOR THESE TOUGH ~ ... t\\t'6\\\\$ , USE COMET FOR THESE TOUGH ...

  4. Heat Transfer and Erosion in the Ares 75mm High Velocity Cannon. Volume 2.

    DTIC Science & Technology

    1977-10-01

    6 . .- 1 ,u 12.0 1.25 1 . 4 11.6 MICROCOPY RESOLUTION TEST CHART NATIONAL BUREAU OF STANDARDS - 1...SHORT BARREL RETAINING COLLAR 7 4 IN-WALL THERMOCOUPLE DESIGN 9 5 INSTRUMENTED VASCOMAX 300 SHORT BARREL SHOWING TYPICAL EROSION RINGS 11 6 VIEW OF...00 00 \\0 N r 00 (’ 4 LIn - 4 (’ 6 00 tnV -~~~~~~~~~~~~~ \\ .. . . 0𔃺 𔃺’ 0 𔃺𔃺𔃺 𔃺 %C0 \\D ’. >-i ~~~~~~~~~\\ 110 Nn N ’.0 t-- I i i I u . . 4 .J r-r 0t

  5. Cost of Irradiating Bacon and the Associated Energy Savings

    DTIC Science & Technology

    1979-03-01

    Irradiated Food(s) Consumers Irradiation Cost Analysis Energy Savings Stan 1 izatlon Consumer Acceptance Meat ~~~~~~~~~~~~~~~~~ ~ ô. ~ iii~- ) I I...eliminating nitrites in bacon would reduce or eliminate the formation of highly carcinogenic nitrosami~es, but would Increase the threatof botulism...Sterilized by Irradiation, bacon without nitrite does not contain nitrosamines and does not cause botulism. Consumer panel taste tests show no difference

  6. 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

  7. NEW BEDFORD, NEW BEDFORD, FAIRHAVEN HURRICANE PROTECTION - NEW BEDFORD, MASSACHUSETTS DESIGN MEMORANDUM N0. 2 (02/29/1960 TRANSMITTAL LETTER ATTACHED) - STATE ENHANCED REMEDY (SER), 02-01-1960, SDMS# 70005572

    EPA Pesticide Factsheets

    2013-06-11

    ... The gates consist of two similar leaves .with radii of 90 feet and overall height of 61 feet. ... I ~~~~~o~~~~~de~~~~~e:h~~h a beveled ...

  8. U.S. EPA, Pesticide Product Label, RANGE CATTLE LIVESTOCK & SHEEP DIP CONCENTRATE, 03/02/1984

    EPA Pesticide Factsheets

    2011-04-21

    ... CiSDc~e of in a ~an,tdr.f ~arCf1:1 )r lnc~'1erd~~cn, crt 1~ d~~owe~:'/ sta~e ~nc :oca1 aLJt~ori~ies. ~~ :urp~~c. :; Jur··~~, s:a, :~~ ~f ;~~~e. ...

  9. U.S. EPA, Pesticide Product Label, DUPONT REQUIRE Q HERBICIDE, 10/07/2008

    EPA Pesticide Factsheets

    2011-04-14

    ... t~~t~~a~:t!!~lj~~~" . sterner ence.a licationsof REQU1RE® Q;:asweU;: . ~~fi~~, appljs~,~i~(s)~"gfp~qd~tslips,~~~,i;/, .DuPont. .•. ...

  10. Quiet Time Lowest Observable Frequency (QLOF) Calculation Program.

    DTIC Science & Technology

    1979-04-01

    sorption controlled effect. The major cause of absorption at low and midlatitudes is the solar created ionospheric D-region. During quiet solar...1• t~~’~ CL~~F ‘ PFA L IC rI ,r 4r,~~~~u’~ ~ pa~~~,~~n p .r I3P1(7 . In , .1CF( ,n, , -~~p( , ) L W ‘5 t 1PFNS i” ~. cC y o ) .MII F c I n~~.nc1

  11. Risk Analysis in Support of the Chemical Stockpile Disposal Program (CSDP). Volume 2. Consequence Data

    DTIC Science & Technology

    1987-12-17

    OO O~oO~o OQOQCoOQOO 0000000000 UI z 00.00000000 0 0 0 0 0 0 0 0 0 0 0 0 U- (11KW f1 0Z =. -c OQ OO OO O OO O OO O OO O OO O OOIn O-WO 0 0 00 0 0 0 0...I.-.Oc.eaa aL ac ca ac aa ec a - acu~~~~~~~~~~~~~ .*..**-w aaca a8ac c e c acca ~~~~~~~~C a a9 a a ! a! a9 an aaacaaca aa aao ecaaaa z " .- C; Va ~cc a

  12. Virtualization Shares: Feasibility and Implementation in the USNA Computer Science Department

    DTIC Science & Technology

    2010-03-10

    34 ,< > ~n: 0: ~ ~ ~ " H ! " qo" ~ p. r ". -H~ hHH q r~~ ii!’:- "~ ~~~": ,..a",, :: ~_ a ,, ~~ it ~~ i{ <= ~ ~ ~ ~~ ~ ~~ (~ ~ ~ 2 ~_ ;2

  13. U.S. EPA, Pesticide Product Label, LEMON FRESH, 09/25/1985

    EPA Pesticide Factsheets

    2011-04-21

    ... _e_c_a_~_~1~0? r'L ~t_at ~~_~~_!.~ ~~ldrd to Hu~_a~.'l_~_~~_ d5?~esJi£~~~~als DANGER ~eep Out of Reach of Children, Corrosive Causes ...

  14. U.S. EPA, Pesticide Product Label, , 04/24/1996

    EPA Pesticide Factsheets

    2011-04-21

    ... egg-bearing ·or· pregnant roaches Eire hiding. ... CA UTI 0 N: ~;eE!.u~~s~n~~ d~a~~i;~o~~o~~I;a~~EN FOR USE IN COMMERCIAL, INDUSTRIAL ...

  15. Prime Contract Awards, Fiscal Year 1982.

    DTIC Science & Technology

    1982-01-01

    a~~~~~ ~ ~~~~~~~ a0-aa a)N-N- - a a a N~N-N O a a aIa t N ’Z aa N N a a a1 a1 a, NaI a’ N Na C o~~~~ a - - a ’" -- a No NEni -aaaaN’- a a . -- MN ol

  16. U.S. EPA, Pesticide Product Label, , 03/20/1975

    EPA Pesticide Factsheets

    2011-04-21

    ... i4 S ~"aula~ Lt;i ... Po ~ct 4rci~ ~~£, tat~~~ ccnd~tic~~ ~av~~ d~{~t !\\r~ 4~~a) :,cat~d. 0: ~ct eO'lt~~i~ar~ ~al ... chemicil descrlntl~" on the la~el dnd '. ...

  17. European Scientific Notes. Volume 7, Number 6.

    DTIC Science & Technology

    1953-03-15

    b — l o — s 3 T1~~~ :cI i i tics f cr Research In Nu; leer Phva :cs aol Co5mic .t..ys ~~ .. A.’_ ...:.:..s...-~ by ~~~~~~~ aria t~~ r , bI~tge: C. 1

  18. Multi-Model Validation in the Chesapeake Bay Region in June 2010

    DTIC Science & Technology

    2013-05-31

    ADOR/Director NCST E. R. Franchi , 7000 Public Affairs (Unclassified/ Unlimited Only), Code 7030_4 X no ---~~~~~~~~~~~~~~~-~-~~-~------------ thor...US Navy at global , regional and coastal scales (Rowley 2008, 2010). The NCOM model in the Chesapeake Bay region for this exercise is configured in...derived from the NRL DBDB2 global bathymetry database. Boundary forcing and initial conditions were extracted from the East Coast NCOM which has a 3-km

  19. Solid State Clipper Diodes for High Power Modulators.

    DTIC Science & Technology

    1978-11-01

    modeled at low powers and later confirmed in actua l P W pulsar operation. 0~ \\ ~~~~~~~~~ . ~~~~~ .. . .— - - I. ~~~~~ 3 J~ItV~ . \\ W \\_ UNC l ASSIFIE...and CG is the di ide api-i tance to 1avg — Ip ~ j- ground . In our design the worst case diode leakage (I 2( lO ~C) was 15 milliamperes (mA) at I kV...without it. I2rms 1p 2 ~~ ( 4) the diode junction capacitance and stray l’nns — 5 x lO ~ A 2 capacitance affect the voltage division whenever the

  20. Evaluation of Lubrication Systems for Isothermal Forging of Alpha-Beta and Beta Titanium Alloys.

    DTIC Science & Technology

    1977-11-01

    in u i u , ’ F~~~U BEVCSR E CC’W11F.TJNG PORNI ~\\ ~ - I~JI~*lNUllS1IIl a, AccI$$IOM N ICIPIENT - ~~~~~~~~~ I _ _ _( 4 T ITL E (~~~ AOlIU ~J

  1. U.S. EPA, Pesticide Product Label, SANI-CLOTH PLUS GERMICIDAL DISPOSABLE CLOTH, 10/30/2007

    EPA Pesticide Factsheets

    2011-04-21

    ... Escherichia coli (E. coli) 0157:H7 (AIQGE~5Jj:5P) .... ... k1~~~g~:g~l~~I~r~;,'~ 1~~~~:e!g:'tEi#ure~"wiP.Ei!:c)~~b;s:;[~H~';iji~9J!Ii;~~] ...

  2. Economic Effectiveness of Mandatory Engine Maintenance for ...

    EPA Pesticide Factsheets

    ... SOCIAL IIIIII~~II~'IIII~~II ::¥~~NN~~~~~G MODEl ... failing an inspec- tion based upon a rejection criteria for each maladjustment are then sent ...

  3. Modeling Human Decision Processes in Command and Control

    DTIC Science & Technology

    1983-02-14

    principle , calculus of variations, least squares, etc. 7 SALPHATECH, INC. Thus, the...34"""~~~~~~~~~~~~~~~~~. ." -. " ""’./’ ’ • "" -" - -".. "-.... •..... ""........."-. -....... -.............. r ALPHATECH, INC. to equate what a human does with what he should do. Employing this principle "of bounded rationality, the norm’tive-descriptive...mechanism to describe these salient task features. In essence, the SHOR paradigm is derived from the stimulus-response (S-R) principle

  4. Extracorporeal Perfusion without Anticoagulation and the Response to Endotoxin.

    DTIC Science & Technology

    1978-05-22

    AD— A057 1415 OKLAHOMA UNIV HEALTH SCIENCES CENTER OKLAHOMA CITY FIG 6/16 EXTRACORPOREAL PERFUSION WITHOUT ANTICOAGULATION AND THE RESPON——ETC(U) MAY... EXTRACORPOREAL PERFUSI ON WtTHOUT ANT1C~~GULATION AND THE.•RESPONSE TO END TOXIN B K BeUer, L T Archer, LU ~~~~. S. 0. Kosanke, and L. B. Hinshaw...I PROJECT NO. NR 207-040 - .-.~~~~ ( TECHNICAL REP~~T.NO. 125 ~~~~1r EXTRACORPOREAL PERFUSION WITH0UTJ~NTIC(Y~GULfihIoN AND THE

  5. An Evaluation of the Effectiveness of the Navy’s Human Resource Management Survey as a Navy Enlisted Retention Management Tool.

    DTIC Science & Technology

    1979-06-01

    especially 1 ~f~ yy ~~~~~~~~~~~~~~~~ March 19, 1 979 , p.34. 12 among those individuals whose background characteristics indicate relat ively low...lab i l i ty — which is periodically conducted on a 12 to 18 month cycle. Issuance of the Human Resource Management Survey during the Human Resource...Management Center personnel providing Human Resource Availability services. Due to surveys being administered in 12 to 18 month cycles and tour

  6. U.S. EPA, Pesticide Product Label, , 11/23/1966

    EPA Pesticide Factsheets

    2011-04-14

    ... r ~ ~,1]l~ ~ ~{Ql1! !IINK( I ~~~.~itt~~~I~~ 11 l ~~~~~ t· --' L . . ~_".... ___ . __ . ..--J ' . • t ) IL " t~S .. 50· Formulating Information! ...

  7. U.S. EPA, Pesticide Product Label, BAS 516 ST SEED TREATMENT FUNGICIDE, 05/30/2007

    EPA Pesticide Factsheets

    2011-04-21

    ... Ii: lq I JiOTectlCI[r a~Jairl,;t seeci-[x,me Tun;;11 ... Product Use Rate in oz/100 Ib Seed (Ib ai/100 Ib seed) ... t~~e~a~~~J~-~~-d-~i~~~~~see f~~'~g ...

  8. Mathematical Techniques for Nonlinear System Theory.

    DTIC Science & Technology

    1979-05-01

    7 7 AD—A078 715 FLORIDA UNIV GAINESVILLE CENTER FOR MATHEMATICAL SYS——ETC FIG 12/1 MATHEMATICAL TECHNIQUES FOR NONLINEAR SYSTEM THEORY . (U) MAY 79... System Theory / 61102F ~~~~~ ~ ~~~~~~~~ Gainesville , FL 32601 L ~~~ CONTROLLING OFFI C E NAME A N D ADDRES S . Air Force Office of Scientific... System Theory During the past year, the major effort under this grant was work by the Principal Investigator (R. E. Kalman) and by E. Emre

  9. A Study of the Technical Feasibility of Developing a Standardized Energy Control System Specifically for Army Facilities.

    DTIC Science & Technology

    1977-08-01

    J I i• ii I WM ~\\ppi~~’cd I~~i public ~ck~ c d is t r ihuf lun mliii I i ! ____ -~~~~~~~_ - —~~~~ r...The contents of this report are not to be used for advertising, publication , or promotional purposes. Citat...of thu report) 15., DECLASS IFICATION/DOWNGRADING UNCLASSI FlED SCHEDULE 16. DISTRIBUTION STATEMENT (of this R.port) Approved for public release

  10. U.S. EPA, Pesticide Product Label, DUPONT MATRIX HERBICIDE, 06/26/2007

    EPA Pesticide Factsheets

    2011-04-14

    ... Q\\Vn tOflla~~~§~9:ir~~ts~~~~ ilJl~~tra ... purse (Capsella bursa-pastoris) Wild Radish (Raphanus raphanistrum) ... t See Specific Weed Problems 9 ...

  11. The Effects of Aerodynamic Heating and Heat Transfer on the Surface Temperature of a Body of Revolution in Steady Supersonic Flight

    DTIC Science & Technology

    1947-07-01

    HF..-I.T THA.:\\SFER 0.:\\ THE SnlfACE TDJPER.Hl’RE Of ... BODY OF RE’·OLt·TIO.:\\ 471 o~~---~~~--~~~~~--~~~~--~ 1.2 1.6 2.0 2,4 2.8 3.2 Moch number

  12. Modification of Savant to Run on the PDP RSX-11M Operating System.

    DTIC Science & Technology

    1982-01-01

    c . C 2 L41~~~j 4 1- 0 1- . .4~~~~ IM hiit W 1. 1 . ~ W w~0.~~~L 0. wf1 - W - i 1 - 2 hz1 go (a4 1 .1-~~~~~ c- w-O.. b . m h ~ .. C 1 4 L0~-. L

  13. U.S. EPA, Pesticides, Label, CUPRO 2005 T/N/O, 7/6/2011

    EPA Pesticide Factsheets

    2011-07-19

    ... rl!.4gt§ig~)ig~.]tOd~~MJ?~.'.r: ~~~iS!f¥i~§i~;i!X~~fu'~Y)~!l~: c~!i~~$

  14. Explosive Forming of Butt Welded Pipe Reducers.

    DTIC Science & Technology

    1979-04-01

    Ao—A 072 I3Q NAVAL ORDNANCE STATION LOUISVILLE KY F~ G 13/it EXPLOSIVE FORMING OF BIJTT WELDED PIPE REDUCERS. (U) APR 79 M W JO$*4SON UNCLASSIFIED...NOSL MT OS2 _ Eli _ _El [LII] DliB I I —~~~~~~~~~~ I 4 1 V S -. RB’ORT NO. M1052 AP~t 1919v-fl o~toswE FORMING (j~~c BUTI WELDED PIPE RE~~~ A PQWECT...MING BUTT WELDED PIPE REDUCERS A PROJECT OP THE MANUFACTURING TECHNOLOGY PROGR AM NAVAL SEA SYST~~(S COMMA ND fiNAL REPORT NAVAL ORDNANCE STATION L

  15. Approaches to. Establish

    Center for Food Safety and Applied Nutrition (CFSAN)

    ... if this a~ro~h is used, the ~~~~ld shot$d be replaced ... of safety are pr~~~b~ in section 4&2(a)( 1). Food ... is that the BMDL is not con~~~~ to one of the ...

  16. Ultra-High Frequency Superconductive Devices

    DTIC Science & Technology

    1991-05-01

    indicate that NbN, -,C sputtered from a Nb target in an Ar/ N1 /C4 ambient 4.s with inctions can be successfully employed as local oscillators at no...oic h eie austoe deece . Figurue oesotu o ja aA-te 3.riato Measehloa osciors sina htigh L eletoe tion~~~~~~~~~~~~~n frqunc ofqunc the shw nfgr

  17. Human Health Exposure Assessment for Rocky Mountain Arsenal Study Area Evaluations. Volume 6-B. Western Study Area Exposure Assessment Version 4.1

    DTIC Science & Technology

    1990-09-01

    Prpae f9 r FIUR ?--81L C)ora 2Aagv 61iefrPoe n hs lAnl sDtceRocky~ ~ ~ ~~~~~~~~91 O~~iiAsea lau IthnoLbv ndctrLvl Abar~~~ ge14 15~ rigE 0.4n, ar

  18. Standing Fast: German Defensive Doctrine on the Russian Front During World War II; Prewar to March 1943,

    DTIC Science & Technology

    1986-09-01

    GmnofesvoealnsMAzovebr192*5 Cacau 5.. . Iv . s . ** .~~~~~~~~~~~ -? %JP~’ 5. . ’ ~f*. * ............................ t’ *S 5%i Soviet forces in place before Moscow.2

  19. Characterizing Munitions Constituents from Artillery and Small Arms Ranges

    DTIC Science & Technology

    2011-05-01

    SCALE LEGEND D QUATERNARY ALLUVIUM D ~b~.’rr~EfoER~~o D ~~~CF~ri’~!R8~ EOCENE D ~lci’~~~~~b~~~<f~N~UARO and ~PREDOMINANT FOREST t::J WETlANDS

  20. U.S. EPA, Pesticide Product Label, SWEETLIX FLY CONTROL RABON MINERAL/VITAMIN MOLASSES BLOCK, 10/16/2009

    EPA Pesticide Factsheets

    2011-04-21

    ... A Supplement, Vitamin 0-3 Supplement and Vitamin E Supplement ... CHOICE source of sail, olher minera~ and vitamins. ... n~~~~~r:at~~b~~tt~j~~r:e ...

  1. Deployment of Lightweight Shock Mitigating Boat Manufacturing Innovation

    DTIC Science & Technology

    2012-12-21

    70 LC1- AMI- Z Displacement- Deck ~ HHH ~EEE~~~~~~~ ~~~~!!!!!!~5...between bulkheads Applied to two panels and included stringer 69 LC1- AMI-10 psi Pressure Load 70 LC1- AMI- Z Displacement- Deck ~ HHH ~EEE

  2. U.S. EPA, Pesticide Product Label, SODIUM HYPOCHLORITE SOLUTION, 10/26/1990

    EPA Pesticide Factsheets

    2011-04-21

    ... JUL!\\t!<:. ~ can(~ lO':'C~ ~ rf1~onl; ~~~1~~ ~~ : t~v!rcn.entil ~r~:!tt~~~ ~;e,(!. ... Jt;l~. ~er ;~~can(~ (o.:.c~ !be rp;:OOii ~!~!( of :~ t~y!rcn''"t~l ...

  3. U.S. EPA, Pesticide Product Label, BIO-GUARD ET-70 CHLORINE CONCENTRATE, 10/02/1971

    EPA Pesticide Factsheets

    2011-04-14

    ... I ~ • 1 I. • . ~ j ~~~~fa'j~ :::,e:!:~lt~~n;,~: ; r~"w7rhl~~~~:I!~:'! C:--==J irritating and bozardous gose •. Store In a cool dry place. ...

  4. 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.

  5. Estimates of Population Exposure to Ambient Chromium ...

    EPA Pesticide Factsheets

    ... 1!~~1~~~~f~~~~~t~k':.~:Yf ... Chicago, IL 2,142,814 40 Jones & Laughlin, East Chicago, I~ l,!o08,S53 17 I I I I I I ' i I I i I i I I ! ! I ! f. Simonds S!:eel ...

  6. Research Program in Tropical Infectious Diseases

    DTIC Science & Technology

    1992-12-01

    Individ- patiis B and delta in the southeast of Chiapas , Mexico . uals~~~~~~~~~~~~~ inetdwt B h r oiiefrHeuae Aivosdelrimstigdcon Medica ( Mexico ). 20, 189...patterns of drug resistance of Neisseria gonorrhea in various regions . 4. Determine patterns of malaria transmission; maintain surveillance for chloroquine...remote sensing models developed for use in predicting temporal and spatial changes in malaria vector abundance in Mexico , in a second ecologically

  7. Molecular Characterization of Attenuated Junin Virus Variants.

    DTIC Science & Technology

    1992-07-14

    0 0) -C cu - WLM-=. u,0 38 - kA .- -- <ICI A A A -- Z2 A~~C A* A A AC- A . ~ ... A~JA 2 A A a U A 5 AS :I AC -1 zAU ɚ~~ AA AS>.. - ~ ~~~~~~~~ A- A...August 1990. Silvia Adriana Moya (DNI 5.968.287) Secretary since 15 May 1989. (*) National ID number in Argentina (equivalent to SS#)

  8. U.S. EPA, Pesticide Product Label, COYNE FORMULA NO. 266, 03/01/1990

    EPA Pesticide Factsheets

    2011-04-21

    ... r ~l~rol'~~l~r 1~ accnr~an~~ with 'I~~' ~~tio" ~f'·'. Y0~rr~)~~~ C""~·L ..... Ir."""-iuct c"r,c;"i.tlJ"'r~ ;'C~' ',~nt:" .)' ttl"Sf' c"')ndl1':ttjr;~ • ...

  9. Atomic and Nuclear Interactions of High Energy Photons and Electrons with Matter.

    DTIC Science & Technology

    1975-09-29

    IJ / VIh /hh1 ij~ ~ 111/ ~ ~~~~ ‘a” • •- • ~~ iitjiJ ~t~I~I1 J(I’,n) 17iTI~f ( ~ ,2n)II ~~~~~ I . a p g ~ ~ p p0 . — T:I Shacklston (Sh?t) LI

  10. The Chemistry and Applications for the Solubilization of Chromate Salts in Nonpolar Organic Media. Part III.

    DTIC Science & Technology

    1979-03-23

    C(U)MAR 79 KG C L A R K . .J OiiR I LA~ICLASSIFIED NADC— 7e017—60—PT—3 Ni l , _EIEIDHUU 10 r ~ I ~ 1315 f f1 22I~~~3.5 4 4 2 01.1 ~~~~ = — • ‘1MF2S...CENTER Warminster, Pennsylvania 18974 N 23 MARCH 1979 / ~~ r ~ ~~~~ IR 5fl~~~NO. 1gC l7l APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED c_) UI...IS. SECURITY CLASS. (of (AS. rspovt) — - r ~)~ \\ - - Unclassified~ i ~~~ I I ( I5~ . DECLAS SIFICAT ION/ DOW NGRA 0I NG / — — SCHEDULE IS

  11. GPS Tides and Datums

    DTIC Science & Technology

    1994-07-01

    REPORT DOCUMENTATION PAGE Form Ap~ovd -qmp Pu~~~~~~~~~~hc~~~~~ omef.A Nu0001U~ 0Itg O Mcq ~n, ’tmoa1a q 0 0 fft *cuqIO~ ’W𔃻i.q~ii os .ete .7qO0t.Aqea...water level heights. Using OTF technology it should be possible to obtain a time series of water surface heights to an accuracy of 1 to 2 ymfa...receiver location. 14. SUBJECT TERMS 15. NUMBER OF PAGES On-the-Fly, study of water levels , datum, Bay of Fundy 10 16. PRICE CODE 17. SECURITY

  12. A Rapid Item-Search Procedure for Bayesian Adaptive Testing.

    DTIC Science & Technology

    1977-05-01

    properties of the • procedure , they migh t well introduce undesirable psychological effects on test scores (e.g., Betz & Weiss , 1976r.’ , 1976b...ge of results and adaptive ability test .~~~~ (Research Rep . 76—4). Minneapolis: University of Minnesota , Departmen t of Psychology , Psychometric...t~~[AH ~~~ ~~~~ r _ _ _ _ A RAPID ITEM -SEARC H PROCEDURE FOR BAYESIAN ADAPTIVE TESTING C. David Vale d D D Can David J . Weiss RESEARCH REPORT 77-n

  13. U.S. EPA, Pesticide Product Label, GOWAN EPTAM/ACETOCHLOR 67.8%/16.9% EC HERBICIDE, 06/27/2005

    EPA Pesticide Factsheets

    2011-04-21

    ... l i FO:''''i·l·i;r~een~:~~~lSjetnin .• ~ v.'na:' :i'S~~~1~~i4'il~0~~j~~i~j Use the lower rate for light infestations and coarse _ Fo~ta Yellow Satan, . ..! ...

  14. Craig AFB, Selma, Alabama. Revised Uniform Summary of Surface Weather Observations (RUSSWO). Parts A-F

    DTIC Science & Technology

    1976-06-15

    amaAt,~~~ *~~~~~~; 4c.e,. DQ550 453 0. 8FI93 Ttl < etBIh 24172 30786.1_______ i-P K. W Depoii 81019 308716~.J .53 198 32 ~.5 a 7O0~~t 1 3539 -5339t76

  15. U.S. EPA, Pesticide Product Label, SPEED ZONE ST.AUGUSTINE FORMULA BROADLEAF HERBICIDE, 11/23/2009

    EPA Pesticide Factsheets

    2011-04-14

    ... 9°nt?i~:~rf.j~~~in~1?,9.i~a.niQg;~h~8?ntcii:q~~:~~f~r~;:~h~J.,d,s~'9.~al::i;~~~~ e,'t~sp ... Wind Speed Do not apply at wind speeds greater than 15 ...

  16. Antarctic Sea Ice Analysis, 1991-1992

    DTIC Science & Technology

    1992-01-01

    34,, 2 9 o,4 .12 004 ýM X K(ý:-Iz 0 ~~, 2Q N o :454, S’ I- 4OT100 410 9901 15 01~000000015404 S 13255 25" NOAA-1.20, 00~~ 00004~~~~~~~ i r’’*0~61 d00M0 6

  17. U.S. EPA, Pesticide Product Label, WORKHOURSE SAPSTAIN AND MOLD CONTROL PRODUCT, 02/19/2008

    EPA Pesticide Factsheets

    2011-04-21

    ... ' the .R,~lstrat~~C;~t:'ISlori prior., t9,,4!le ,0f.me!~~~U,,'cornrr'erc~. ,In a~¥ cOir~~r&rdenc~i~n ttils'product alw.aY,Sr~f!ilr,to~~,;~eE;P~~~ . 'y ", ...

  18. Nonpoint Source Monitoring and Evaluation Guide: Final ...

    EPA Pesticide Factsheets

    ... il!!~~!i!I~~~~I~~ tIC Leachate first ... per hour), maximum intensity (inches per hour), time since the previous storm (hours), antecedent rainfall (inches ...

  19. 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).

  20. 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

  1. Crew-Centered Cockpit Design (CCCD) Field Demonstration Program. Volume 1

    DTIC Science & Technology

    1993-12-01

    JM O4No 0104-0 188 " it ,~~~~~~~~~~~~~~ 10 54’ f 0 ’?1) I~f~fit.* fJft1 f%b -2’. tf1 - . tfq~S O r I AGENCY USE ONLY ti’viv~ blinfAl 2 REPORT DATE 3 EORT...difficult due to the absence of a full-featured text editor. For example, there are no search, replace, or text-fbrmatting capabilities. It should be...Teleuse was eliminated early due to its exceptionally high cost, which was more than twice that of the other two systems. UIM/X (References 12 and 13

  2. The Role of Learning Strategies in Second Language Acquisition: Strategy Use by Students of English

    DTIC Science & Technology

    1987-01-01

    pasar y pienso en lo dema’s y si me puede recordar de vuelta, o sea, me trato de grabar la palabra pero sigo con la lectura . Entonces le entiendo lo... la soluccion del problema. If you’re thinking of a picture, say so. If you’re thinking about something A-i -IW ~ 4w’ ~~~~~~~~~’ u~~~~~~~’V17-6,r P ’W...del Estado de Michoacan, el 25% de los pobladores se dedican a la alfarerifa. - -Cuantos habitantes de esta pequena poblaci6n son alfareros? CHAVE THE

  3. NEW BEDFORD, HANDWRITTEN NOTES REGARDING MEETING ON SOUTH TERMINAL - STATE ENHANCED REMEDY (SER), 09-28-2012, SDMS# 529022

    EPA Pesticide Factsheets

    2013-06-11

    Cf(zt ~~n,.'fb-~.. · wl CJfiiU1 , ~ Cffuf; J~) , Ctw, /IA.Au 1 ~~ , ftw ~L-- ~'JY)VY~) t~~ a~t~~~~~f«Jetud.AJ1/P v..>t'tte #ttiJ hn cLute 10 k~ fo ~ ~ ~lzt( ...

  4. Naval Applications of Virtual Reality,

    DTIC Science & Technology

    1993-01-01

    Expert Virtual Reality Special Report 󈨡, pp. 67- 72. 14. SUBJECT TERMS 15 NUMBER o0 PAGES man-machine interface virtual reality decision support...collective and individual performance. -" Virtual reality projects could help *y by Mark Gembicki Av-t-abilty CodesA Avafllat Idt Iofe and David Rousseau...alt- 67 VIRTUAL . REALITY SPECIAl, REPORT r-OPY avcriaikxb to DD)C qg .- 154,41X~~~~~~~~~~~~j 1411 iI..:41 T a].’ 1,1 4 1111 I 4 1 * .11 ~ 4 l.~w111511 I

  5. U.S. EPA, Pesticide Product Label, MAQUAT 128-NHQ, 06/23/2009

    EPA Pesticide Factsheets

    2011-04-19

    ... Escherichia coli (E. coli) and Staphylococcus aureus (Staph ... that can lead to possible infection/disease in ... Gt~) '~'I;i;$:~~b~~~~~r;#k~1~~~f:~}!tt ...

  6. Classification of Intact Stability Standards for Dynamically Supported Craft.

    DTIC Science & Technology

    1979-10-01

    nineteenth century. By 1914, planing boats had been developed sufficiently to be used successfully in World War I. It appears that hydrofoil craft, which...of ship, It ’, ervice jeed sVl or .ago. 281s PAGE I S BS T QUAL1t~ TY PFCJ= .......... -HM TO DOC . ~~~~~~~~ ~~~~~~ ... ,__.-. ul ... . _:L._. TABLE 3-1...1l- A 1".. A , L "lp | it [ -ff. lfv-tiv44 1.d. P|I,, tdv. An- rAlnj 1. eq slh W-rr t - ii, ,J 1’a.g . s 15yl.ar svr l g ,’ii.l n Ir 1, hi , tan1 .40n

  7. Tri-Service Literacy and Readability: Workshop Proceedings.

    DTIC Science & Technology

    1980-03-01

    LN zC t’ DC D -2l C CC U CC., r C CzC.C-.C, CC C ~ ., caCQ.. *’UC - -C CL UQC’CC Ci - CT 0 --. . C DJZDCU- CC C C. C C...8217 flCCD.- CC, CCC~4J o zC C-Ca C ,.-C,-.O ,-,- CC CC,.. -- r C C,- -z~~~~~~~~~~~~~~~ (U’~’ C- O’ ,.0 C CCC,.. D Ca D CCCO.C - 0.a l F--Ci E CC CC CDO C C...understanding in problem solving. In Catellan, N. J., Jr., Pisoni, D . B., & Potts G. R . (Eds.), Cognitive theory. Hillsdale, NJ: Lawrence Erlbaum

  8. Synthesis and Structure of Hexamolybdobisorganoarsonates.

    DTIC Science & Technology

    1976-11-01

    lU tnm s) —.~ ---- ---~~.“ . --. - ~~~ - -“ —‘ ‘ - ~~~ - — /~ ~132~ waki L .Aajdovi~ ”, J.K.Ata1ick, M.T. ~~’oPe s - • C O . Quicksall~ - - 544 1

  9. U.S. EPA, Pesticides, Label, MAQUAT 20-M, 12/9/2010

    EPA Pesticide Factsheets

    2011-04-13

    ... entire lawn to prevent spread of infection at least ... Escherichia coli (E. coli) and Staphylococcus aureus (Staph) are ... Y"ii:t~~ii:M 1~~~k;:~~1~~;;{i'~iTiQl ...

  10. Physical Environments, Habitability Perceptions, and Health.

    DTIC Science & Technology

    1974-09-01

    Multiorganizationai Study . Inst i tute of Behavior& Research (cont IS. KEY WORDS (Conhinu. on ,.v.r .. aid. ii i.c.a.ary and id.ntily by bloek numb...HAB I TABILITY PERCEPT~ ONS AND HEALTH_________ I E K E GUNDERSON r REPORT NO. 7k—58 I ThLz docums’ut has be.a appro,Sdl J ~1or public reler~. aid...4: ~~fI~~~~~C~~~~ i~~~3 / / In Men t~n SOQUZZ Systems Results of a 2~ree-y ear Mul tf ~orgcm~z.zattof lal Study ~ngtitute of Behavioral

  11. Research on Heat Resistant Transparent Interlayers Based on the Ethylene Terpolymer.

    DTIC Science & Technology

    1976-08-01

    the s ; - c i v i n g machine as it is about to pass under th~ kn if’e .The block was skived into 10, 30 , and 50 rail sheets. Laminat es of glass...reviewed and is approved for publicati on. Project Monito FOR THE COMMANDER T .J ~~ EI~~~~~~JR~,C~~~~~ Composite and Fibrous Materials Branch...iated under Project No. 29lZ~, “Non—metallic and Composite Mater ia ls , ” and Task No. 03, “Structural Plastics and Composites ” . The work was

  12. Asymptotic Bounds for Solutions to a System of Damped Integrodifferential Equations of Electromagnetic Theory.

    DTIC Science & Technology

    1979-05-28

    of integrodiffereiTaT~- equations governs the evolution of the components of the electric displacement field in a simple class of rigid holohedral...vacuum so that j — C and J~ — c E , H = B. In0 [3] and [4] this author has treated the evolution equations associated with the Maxwell—Hopkinsofl...F .~~~~~~‘ r - — ~~~~~ ’~~~ “~ I I be viewed as a linearized version of a more general theory introduced by Volterra in 1912 [5] to treat the case

  13. 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

  14. 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.)

  15. 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.

  16. 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.

  17. 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.

  18. U.S. EPA, Pesticide Product Label, AN1004 EOGAS 4, 01/05/2006

    EPA Pesticide Factsheets

    2011-04-21

    ... spores known at 50oG,within thelsterilization pycle providing that the spores have not ... color change reaching i~~' t:ri~i~~~;p'q, ~!:f?t2'~~~~s~l~ Pi ...

  19. Flight Test Evaluation of AVOID I (Avionic Observation of Intruder Danger) Collision Avoidance System

    DTIC Science & Technology

    1975-05-01

    memory registers A through G ( 2048 bit shift registers) for each of the basic altitude bands (1+26, 113 1+6) to store intruder responses. Since the 1...af EV 11z iIIV~ ~l~~ NADlC-75056-60_ _ _- 2 w< -I- LI- ~jw 0IU oo2 W I aJ W %L6fI9~~AVdI tVOV~ aN9Ao ccH % VdI I11813iA-di V GN Ed a3IV0 %AIII1IilV11W...tei mix ;;; c le z - Is’ %~~~~~~~~~~;s AJIiV1 VdI ~ %AIIV~ v~iO VIR 1ý 123 Lz NADC-7056-6 w, M w o ~2IV ONY Ed CIRNIGVNOO at p 00 CLt % 118I3iAVldSIC3

  20. 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.

  1. An NQR Study of TNT Characteristics.

    DTIC Science & Technology

    1977-09-01

    RDX , HMX , a r d some of t he heavy me t al 3~~: id~.s h~~’n for rn.nn ye.~rs been use d as rn~~lit~~ry nii p lns i n’t-~~~~, Thr p h y s i c a l...ambient temperatures of more than one coexisting crystal phase. This polymorphism is known to occur in TNT , HMX and PbN3, and is responsible for a...specific problems of TNT polymorphism and phase transitions were researched . This is one of the problems which is relevant to present day concerns . The

  2. Prime Contractors with Awards Over $25,000 by Name, Location, and Contract Number, Fiscal Year 1992 (Bituminous Paving, Inc.-Datum Maching Services, Inc.)

    DTIC Science & Technology

    1993-01-01

    Fa U ~ 4 0 F0 co00 F 0~ 0~~~ z CC FF; F F (0 FEFn E3 >w 40 pa P4 PO FPi 40~~ ~ 0 HC F F 0 Z 4 F < OF C Z N N z w to F3 C) i3Z 0 CO Q F. 0 r. F0 0 4h...3331*7.30-.4 0 ~ ~ ~ ~ ~ ~ ~ ~ a m x3 Fx3. (󈧥- F3 3 0 (3 .~0 IHC ~ - r 2 00 0.00 F ’> F .0-.. 0co 33.. 13 F 0 1 ~ CO F- 3 F - 2431~~~~~~~~~~~ U)4X 0o F...0( F3 00 0 n ;r3 000 r0o ( -- N r.’- m -- a, m w "D 00 N C> (n0r 0 0) 0 0 , ~ 1 (0.5 0 4CNC, i n ) ~ 04 3 I- F I~~~~C C,) F 0 0o’e

  3. 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.…

  4. Generation of a Composite Grid for Turbine Flows and Consideration of a Numerical Scheme.

    DTIC Science & Technology

    1986-11-01

    section (a) Grids on blade-to-blade surface. WIWcr fb eatv r.t35eaiy aiso lsnbaet-baesrae Figure~~~~~~~~ 4. "eo’ycotuso.4det-ld urae(rmtre-ieso5 .2lcdcmp

  5. AXBT Observations during Trident Warrior 2013

    DTIC Science & Technology

    2013-09-30

    Standard P ::~~ Standard ::= ISOP ··-10.3818) U~E:AST ::=~ HYCOM ~~~~ GDEM 0 .5 (0.4289) ....... , (me an S tD E nor) (1.836) (Ala) U CUP Standard...P f:~~l standard F.~n [1.617] (1 .311 ) I SOP U SEAST ::~~~ HVCOM 1:1’:~1 GDEM (1..663) I I A] 1 .5 AXBT 38.5 38 37.5 s: 37 ~ 3G.5 ! 36

  6. Study of the Feasibility of Using an Advanced Opto-Electronic Imaging Technique for Sampling Mid-Water Nekton.

    DTIC Science & Technology

    1978-11-30

    migration(diurnal) of Mycophidae and siphonophores of the suborder Physonectae. —2— _______ - ~~~~~~~~~~ _____________________________ I-~ The former...ORGANISMS PLANKTON COPEPODS TRANSLUCENT ! ARROW WORMS TRANSPARENT SIPHONOPHORES MEDUSAE AGLISCRA IGNEA FLAMING RED NEMERTEAN WORMS REDDISH ARROW WORMS...383-385 ( 1969) 9. BARHAN, Eric G., Siphonophores and the Deep Scattering Layer, Science, 140, 826—828 (1963) 10. BARHA~M , Eric C., Deep Scattering

  7. Project Work Assignment | Sustainable Stormwater Funding Project

    EPA Pesticide Factsheets

    2010-11-30

    ... J'l.wroprl 8OOljJf!'l fOI 8..... n """ Nwo I.1n DCN N. e_ e_ prog~;"':x~~ment ObI~~Cl~·· unt I ICents) SI:~~~O:t COSI~~od. Max6 Mo•• Ma:t6 ,,",7 1 ...

  8. U.S. EPA, Pesticide Product Label, SEVIN 5% DUST, 11/19/1981

    EPA Pesticide Factsheets

    2011-04-21

    ... "e;;t~~i~:i'·:,~r:.;~. eT~;:': i:, .O~~~:~J It;;;'"lh~''I~;.rP:~,~: t;~~ ';JI.~~ n>nl~ .nd "',"'nlll frU'1 m"lh KPI>I .. d( 1',",41 r.11 and .""rv II) to 14 ...

  9. U.S. EPA, Pesticide Product Label, DACONIL ZN FLOWABLE FUNGICIDE, 02/20/2007

    EPA Pesticide Factsheets

    2011-04-21

    ... " .... chemi¢aI··r~sistalic~(c~te.gQrY.: s~l~ctipn':cti~·rt) : ~h;~~:j~:.~i:t~~~igv~;~~ a~;~f.'~m'.V!~~~iRrd(;(rnate~ai ~I Revised. • shoes plus socks ...

  10. U.S. EPA, Pesticide Product Label, BEST BBC 12-E EMULSIFIABLE LIQUID, 01/12/1968

    EPA Pesticide Factsheets

    2011-04-14

    ... plar,7"":) 1 q'J ;-,I'r Ol.I',' (OTTON, p~EPl/\\~~~ T ~!"~'i!I~~\\.. i)()SrPLANT. PiNEAPPLES: [11'(0(1"\\1' ~'~Lr'~ I.~ .. T ,~,l ~-'lt~~~1:~~'~j ?OSTPLP.,Nf. ...

  11. U.S. EPA, Pesticide Product Label, CUTLASS AQUEOUS FLOWABLE BIOINSECTICIDE, 04/21/1994

    EPA Pesticide Factsheets

    2011-04-21

    ... _ of P .. tlclde Product ... West Langhorne, PA 19047-1810 • ·~~'ti;g" •.. 1a~1";¥tfU1119 111 .• w.taiocoI.#~Mt~;,IiYi!k!;i,!~~. Vi~~~l.fi~H~:~~ ; ...

  12. RADC (Rome Air Development Center) Nonelectronic Reliability Notebook. Revision B

    DTIC Science & Technology

    1985-10-01

    Int sI -- - Q OIL", 2 £j r~~~~~~. I i N Q awcO 44 "- n LinC a~~~~L 5 2 ’ 5 43 0 1- CL .41 &on cc C. t.- & . .4. 00 ’ a 0 00 * Id - IU S ia.J S I...69008 26 .01852 - .01009 . 01871 - .01017 27 .01907 - .00946 .01989 - .00869 28 .01964 - .00877 .02113 - .00709 29 .02021 - .00803 .02243 - .00538 30

  13. Test and Evaluation of the Airport Surveillance Radar Performance Monitor.

    DTIC Science & Technology

    1978-09-01

    U I I; -~~ - ~~~~ 3 ~S I Jill iut~ It i~ Ibruhi t~ I E . c T 5 I~ YS t~~~~~ I3~ TAZLE OF CONTENTS Page INTRODUCTION 1 Purpose 1 Background 1...deficiencies , in a d d i t i o n to var ious tes tbed and ins t rumen - tation problems , m a n y in terruptions were encoun te red b e f o r e a m i n i

  14. Apparatus and Methods for Locating Source of and Analyzing Electromagnetic Radiation

    DTIC Science & Technology

    2015-11-19

    President BY: ~~~~~~~~~~~==~----- CONTRACTOR’S OFFICIAL AND TITLE Nanohmics Inc 6201 E. Oltorf St., Suite 400 Austin , TX 78741 BUSINESS ADDRESS...ANALYZING ELECTROMAGNETIC RADIATION (71) Applicant: Nanohmics, Inc., Austin , TX (US) (72) Inventors: Byron G. Zollars, Georgetown, TX (US); Steve M...Savoy, Austin , TX (US); Michael W. Mayo, Austin , TX (US); Daniel R. Mitchell, Austin , TX (US) (21) Appl. No.: 14/531,247 (22) Filed: Nov. 3, 2014

  15. Stitch in Time: Enabling Change Using Computers: Innovative Uses of Information Technology Helping Providers to Care

    DTIC Science & Technology

    2011-01-01

    l’ults 43 J4 Microalbumin Results 19 6 LOL Results 43 34 Encounters Percentages Done Foot Exams 18% Ey e Exam s 19% Flu shots 26% Pneumo-Vax 26...diagnose and treat. • Shares clinical workload, helps  nurses  and  ancillary staff identify what preventive clinical  measures a patient needs...Quick access to patient‐centered  resources. 2011 MHS Conference Providers and nurses  can review data..................... ~==:=~~~~~~~~==~~~~~ ~E

  16. 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.

  17. Remote Sensing of Crosswind Profiles Using the Correlation Slope Method.

    DTIC Science & Technology

    1979-07-01

    i s ‘What is the aeceptab it’ upper 1 int l t on ~ ~ca 11 i t 4 1 or w h i cli the i n v e r s i o n works in the noi seless case ?” In order to...ions in t h i s pape r . The b e h a v i o r of the pat h-we i g u t I ng fut te t i on W( • c i t s shoi ~t t iii I g . 2 t v a l u a t lOf l...1 Final Repsr~~ -~~ S. PV~~PO~ UWW O~~G; PORT NUMSEN • -S.--__ — - ~~. AUTHON(.) S. CONT R ACT ON GR ANT NUMSEN( . ) ,~ Ri~~~~ J~arakat/ Bolt

  18. National Dam Safety Program. John D. Rockefeller Jr. Dam (Inventory Number N.Y. 665), Lower Hudson River Basin, Westchester County, New York. Phase I Inspection Report,

    DTIC Science & Technology

    1981-08-05

    r .~ ASSIFIED National Dam Safety Program. John D. ASSICATIO1J OWOAGRA01G Rockefeller Jr. Dam (Inventory Number ouL IS. 0:STP.3...JOH A: ROCKEELLE JR. DM.9 Ii Zee~~~~~1- n.,..d*-~~)~ ~ >-. I 20 * * I o u 4V e- VIWN.T MA 21. Ih ftJ 28I ChA S" r . I.’I ’Pi JOHN D. ROCKEFELLER JR. D...AI~~~ ~btt 4f p*~ SCLZ 40 L~~~~-w u 4 1.1l1d~ ___ -I~~-’ JOHN .. AOIEELR R A -*~ - a1 h I VU I I 0 i fe~. f~ ~A I * 1" ~mz ~Z1~t - I +9’-. I ii __

  19. High Velocity Jet Noise Source Location and Reduction. Task 3 - Experimental Investigation of Suppression Principles Volume III - Suppressor Concepts Optimization

    DTIC Science & Technology

    1978-12-01

    j$ 4yO •-•,,,~,--••oo ~ r. ,r.--r - . . . . . .O %N.. . . . . .~O . . . rr.. ~~~~~00 01 1~OO N . . O 40 ~ ~ 00 3 O 0~.~ N O -. O -. ao No ’ o ~~~~C

  20. An Identification of Operating and Support Cost Drivers for Command, Control, Communications, and Intelligence Systems.

    DTIC Science & Technology

    1985-09-01

    8217 - -51 0 0~ ) 4 -~~~~~~~~~ *-1)4 q.4444 I) ~ 44200 . ):~F40 c . U 40 𔃾)C40󈧄 440O ..- .. : 0’ 44).𔃿 S4~44)4044).0~4’) 804) Appendix ±3: Tnesis

  1. U.S. EPA, Pesticide Product Label, , 07/17/2001

    EPA Pesticide Factsheets

    2011-04-21

    ... Clilll¥9UFl&lMllsprdw

  2. U.S. EPA, Pesticide Product Label, ROCKLAND KLEEN-KOW CONCENTRATE DAIRY & LIVESTOCK SPRAY CONT. CIODRIN &, 12/17/1968

    EPA Pesticide Factsheets

    2011-04-14

    ... "~-' ;c-+:cns 1 .... ._""- .. u,-_ u~c ~ack~~Lbers or ~ace ru~~e~~ ~ce ~l;es, ~'lX 1 :uart "~r 4 ~a!lQ~s . ) .". trJt1on. :_1~:; ~a': ~e ~~e:;el !~e~ cr ...

  3. Transform Image Coding.

    DTIC Science & Technology

    1978-05-01

    s ’ ~~~~~~~~ ——- - --- - - - - (Ic s ’ sis l abls ’ t’ i’s i i u u [u l ’ s’s ’i s_ i u sIt ’ dt ’o ’ sisl s ’d oI~it a , o h _ i s ’ i’ss’i so

  4. U.S. EPA, Pesticide Product Label, PENNINGTON SEVIN BRAND CARBARYL INSECTICIDE GRANULES, 06/02/1992

    EPA Pesticide Factsheets

    2011-04-21

    f¥Y' 19 .5 '{I 'I of - j() z",;,,JMl ~ - .: it F..~:I J- VLSL'Lii.~::> d_ (----eEED ~~ :rC"~~., f 'M .... DlUolA".® - 11. ~~~~ G-~:z cT •• L--F .... ~S ...

  5. U.S. EPA, Pesticide Product Label, B-60 RACING BRONZE HARD TYPE ANTIFOULING PAINT, 10/08/1982

    EPA Pesticide Factsheets

    2011-04-13

    ... KEEP OUT Qf REACH QF CHIlDREN. u.. wun odequ ••• vontU_ oIucin9 _,,,,,IOft """ dtying.lo ..... ... 61-lbY ~o~ra~~~iG9ion9 ~~ted ~~tft~Qer l~. l~~l ...

  6. 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).

  7. Baseline concentrations of trace metals in macroalgae from the Strait of Magellan, Chile.

    PubMed

    Astorga-España, Maria Soledad; Calisto-Ulloa, Nancy Cristina; Guerrero, Sandra

    2008-02-01

    Samples of four different species of seaweed were collected monthly between October 2000 and March 2001 from the coast of the Strait of Magellan, Chile to establish baseline levels of trace metals (silver, total mercury, nickel, lead, antimony, vanadium and zinc) and to compare the accumulation capacity among species. The algae included in the study were Adenocystis utricularis (n=15); Enteromorpha sp. (n=11), Mazzaella laminarioides (n=12) and Porphyra columbina (n=6). The concentration range of each metal in microg g(-1) dry weight varied as follows: Ag=ND-0.3, Hg=ND-0.02, Ni=ND-12.6, Pb = ND-11.2, Sb=ND-1.97, V=ND-11.34 and Zn=14.10-79. Results showed that levels of Ag, Hg, Ni, Pb, Sb, V and Zn for all species were similar to those found in other studies for non-contaminated areas with very little influence from anthropogenic activity. Also among the four species studied macroalgae Enteromorpha sp. had the highest capacity for metal accumulation and could therefore be considered as a biomonitor for future studies in the area.

  8. Aggression among male alcohol-dependent inpatients who smoke cigarettes.

    PubMed

    Saatcioglu, Omer; Erim, Rahsan

    2009-12-01

    The authors aimed to explore the relation between nicotine dependence and the severity of aggression among Turkish male alcohol-dependent inpatients who smoked cigarettes, as well as the effect of aggression in these groups. Participants were 126 male alcohol-dependent inpatients who were given the Structured Clinical Interview for DSM-IV, Substance Use Disorder Module (A. Corapcioglu, O. Aydemir, & M. Yildiz, 1999; M. B. First, R. L. Spitzer, & J. B. W. Williams, 1997), the Fagerstrom Test for Nicotine Dependence (K. O. Fagerstrom, 1978), and the Overt Aggression Scale (OAS; S. C. Yudofsky, J. M. Silver, W. Jackson, J. Endicott, & D. Williams, 1986). The authors found differences between male alcohol-dependent inpatients with nicotine dependence (n = 94) and those with nondependence (n = 32) in OAS subtypes. The authors' findings showed that smoking cigarettes-an addiction frequently observed with alcoholism-was positively correlated with aggressive behaviors. The authors suggest that smoking cigarettes may cause aggression or aggression may cause smoking. Observing and evaluating how aggression and smoking cigarettes are associated with alcohol dependence may help relapse prevention and improve effectiveness of treatment interventions in alcoholism.

  9. 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.

  10. 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.

  11. Chemical Stockpile Disposal Program. Emergency Response Concept Plan.

    DTIC Science & Technology

    1987-07-01

    the long term response will likely be managed by...response, the primary management considerations for the secondary response will include emergency medical care, long term health considerations...site, to establish the legal basis for the management structure for the secondary response. 3-4 .~~~~~~~~~L ." ..... .. The long term response to

  12. Final Panel Report on Allergenics

    Center for Biologics Evaluation and Research (CBER)

    ... It il;l J:l'1t! op:i.qion .o;th~ Panel t.ha,t t;h~r~. is non~w ra:v:l,cl~;nC7~i!, to sug~~t;:I,t ,that proc~~~gq ~u+l?at;r~~e :$,ou;r~~ Qt.sp,e~ira!3~P,~};f:f,Jc ...

  13. Visualization of the Flow Field around an Oscillating Model of the USS Enterprise (CVN-65) in a Simulated Atmospheric Boundary Layer

    DTIC Science & Technology

    1988-03-01

    visualization tunnel. The tunnel is of the open circuit type and it draws air into 9 j•;•.,p~ ~ ~ ~ ~~~~~~~~~.... ..•,"r• • •• IWLT - ’ ’•1•• ••!•• • the

  14. A Strategy for Leading

    DTIC Science & Technology

    1988-04-01

    military leadership. A review of old leadership styles is followed by illustrations of two visionary leaders, General W.L. Creech, USAF (Retired) and...Leadership? . . . . 2 CHAPTER TWO - FOUR LEADERSHIP STYLES Overview ........................................ 4 The Historical Style..................4...3 describes the characteristics of four predominant leadership styles : historical, knee-jerker, caretaker, and vi -~~~~~~ % .v~~~-J~ CONTINUED

  15. Shear-enhanced Binding of Intestinal Colonization Factor Antigen l of Enterotoxigenic Escherichia coli

    DTIC Science & Technology

    2010-01-01

    Yakovenko, 0., Larock, C., Kidd, B . , Vogel , V. , eta/. (2008) lntegrin-like allosteric prop- erties of the catch bond-forming FimH adhesin of...NUMBER OF PAGES 14 19a. NAME OF RESPONSIBLE PERSON a. REPORT unclassified b . ABSTRACT unclassified c. THIS PAGE unclassified Standard Form 298...60 40 20 o +-~~~~~~~~~~~m 0. 1 10 shear stress, dynes/cm 2 100 B 1000 () ~ 100 .._ E :l. ::3- 10 ’ (3 0 Qi > 0.1 Shear

  16. Transportation Costs as a Consideration in Air Force Contracts.

    DTIC Science & Technology

    1979-03-10

    17 •‘rAO67 9~9 NOTRE DAME UNIV IN DEPT OF MARKETING F/S 5/1 TRANSPOJITATION COSTS *5 * CONSIDERATION Iij A IR FORCE CONTPACTSaLJ) MAR 79 .1 R STOCk...Notre Dame ~ R~~~~* WORK UNI T NUMSERS Department of Marketing ” ~ /College of Business Administration ) j ~~~~~~~ ‘V3i ait) ‘11/ Notre Dame, Indiana...Government and civilian personnel in the contracting and transportation areas and a review of available secondary information sources. Four research

  17. An Image Segmentation System Based on Thresholding.

    DTIC Science & Technology

    1978-12-01

    referred to as tuoe gjj~ j flj t~zoe ~~~ errg r~ res p e c t i v e l y . Examples of these errors are provided in F ig ure 2 This figure also shows a...h it’ . IV& ’ I’~ I~~ t ’ dl St~ flt~ C t ~ t he ide ~ td ~ a’.’ en t p1 xe I i 0 0 ~ r ~ - c ~~ dI~ + ~~ — 2 I I~ r dr ~~ o — O r* . - ’ 0 — 0

  18. 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

  19. 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.

  20. 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...

  1. Scan Line Difference Compression Algorithm Simulation Study.

    DTIC Science & Technology

    1985-08-01

    introduced during the signal transmission process. ----------- SLDC Encoder------- I Image I IConditionedl IConditioned I LError Control I I Source I...I Error Control _____ _struction - Decoder I I Decoder I ----------- SLDC Decoder-------- Figure A-I. -- Overall Data Compression Process This...of noise or an effective channel coding subsystem providing the necessary error control . A- 2 ~~~~~~~~~ ..* : ~ -. . .- .** - .. . .** .* ... . . The

  2. Three Axis Acoustic Current Meter.

    DTIC Science & Technology

    1979-05-10

    ofNaval Research co N~~~L4-75~C~~~~~~ ’~1i The report con a a brief description of the history of the contract work undertaken , together with reprints of...4V titanium allo y . All external hardware is also titani um, resulting in high stren gth and freedom from corrosion. (j The hardware is electricall y

  3. 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.

  4. 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.

  5. Embankment Criteria and Performance Report, Missouri River, Fort Peck Lake, Montana. Volume II. Drawings.

    DTIC Science & Technology

    1982-09-01

    CIli N N N LJ I> UU () u ~I - 6 0 0 -+ o4’ C. - z 00 > -~2 1~~~~ VCW *- oil-- La 4I (i~~bs S.oj *1iu i 9 I VIH 9-sn c ..-.. w ~ LkJo~ 0L 0 B )0...2100 __2000 w*gpg S-U slV-. Is OOU 1O OOU S OOU . a . 0#0 MR., ? -2200Pautsaj Ist COl toot 00,v An 300 -~~~~ -, ---- ---- I $to U ,S0M 00*aSow STA

  6. Status and Prospects of Computational Fluid Dynamics for Unsteady Transonic Viscous Flows.

    DTIC Science & Technology

    1984-10-01

    including external stores) at transonic flight conditions for which viscous effects are important, and to couple these aerodynamic characteristics with the...OBTAINED * EXPENSIVE FOR MANY RUNS * SCALING (VISCOUS EFFECTS , * CHEMICAL NONEQUILIBRIUM. etc.) USE BOTH TOGETHER - ~. om~innta rv -cliD tor aero:nautical...8217onl’-eir ~ nvsc j 963s 1970s Re-averige, * ’aver-71 :J, ’r ’s 1980S t.urb, enr,, (38 Ius* 19805* ~’ii~~ .r **~’, r o nstead; effects ~~~~~~~~~i, trOr

  7. Advances in Anisotropic Materials for Optical Switching

    DTIC Science & Technology

    2010-09-16

    polarization oflight, Figure 2(b)u.14,18.19, \\,/::1: 1 11 1" ~~§~ I ) \\111~~l\\ I .~~t~· . r illii I ’pQ~~rJ 1’/\\ ~~ \\, ,\\1 ,\\ ~ \\\\ .~: (a) (b) Fig. 2...CW and pulsed beams (materials containi ng two benzcne rings with donor·acccptor, or push·pull , ff-nC] conjugation, characte ri zed by r - I s...ioll, characterized by r - 0.00 I s) tError! Dookm.rk not ddiDtd.] . Azo LCs that combine the high photosensitivity of azobenzenes with the high

  8. BiF(AO+, v’) Radiative Lifetimes and Rate Coefficients for V yields T Transfer and Electronic Quenching.

    DTIC Science & Technology

    1987-04-24

    8217) Radiative Lifetimes and Rate Coefficients for V - T Transfer and Electronic Quenching R. F. HEIDNER Ill, H . HELVAJIAN ,J. S. HOLLOWAY, and J. B...ofoffene. 9. ~ ~ ~ ~ ~ ~ ~ ~ ~ ia U91FO01NGOGNIAIO AE N DDESIIIA T NR.ASK II.~~~~~~~~ WSPIUIOk:TTMET:. .I epn *~~ h Approsp c...collisions of the metastable NF(a 1 h ) state with ground-state BI? molecules, a chemical pumping scheme made efficient by the large densities of NF(a) that can

  9. Final Environmental Impact Statement: F-15E Beddown at Seymour Johnson AFB, North Carolina

    DTIC Science & Technology

    1988-11-18

    as-- " A~r- c ’-f cau~i-- di -stWrbances-at-the-in stT-a- l -~i ons-were-c Iassfe-s military (60% of the installations), private (44,%), and commercial...CD do . . . . . . . . . W . U.ioV4C ~~~~~~~~~~U -- - -w- w w -w0-Iw -4 ~ ~ ~ ~ ~ l w4,4NNf0 t DI O U U ...with other military proposals in eastern North Carolina. The statement indicates the replacement of 72 F-4 aircraft at Seymour l Johnson Air Force Base

  10. 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.

  11. 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.

  12. Industri-Plex, OU-1, Cover Certification Report, City of Woburn Rights of Way and Roads: September 30, 2008: Appendices E-K

    EPA Pesticide Factsheets

    2012-04-22

    ... EpA SW-846 (Third Edition) 1986 ... X."~~~k ••Y_••••~K_.*~,•r~K••••_•••W~_~~ ••• __ q_~~m ••• w~~_w ... 2-Me thy Ipheno l ~ 370 Fluoreno t-() 370 ...

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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 .

  19. 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.

  20. National Program for Inspection of Non-Federal Dams. Scitico Dam (CT 00529), Scantic River Basin, Scitico, Connecticut. Phase I Inspection Report.

    DTIC Science & Technology

    1980-04-01

    ACPArS 5O $L.CP PON30 AP4A CC. -ZOO 1,550 ACAGS re Z4-01 2ZW Zne-r Ra’iin! 4// if 2/ ,idX6.S xග. ’Ro /20%1 A ?~~~~~~~~ AosqSos ~VISy~-Ce(cgs 77~z (Z

  1. 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.

  2. 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.

  3. 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.

  4. Extremes of Moving Averages of Stable Processes.

    DTIC Science & Technology

    1976-10-01

    for -::~e contiriuous-tir e case, a result on sa~ n1e :-~~t~i continuity of stable ~rccess~s is obtained. J~.I3 1°70 subject classification: Prinary C...we let ~(x,y) = ~~~~ 6~(x,y) where 6~(x,y) = min(l/3, h(c ~ x,c1y)) and h(c.x~c~y) is the quantity given on p. 113- 115 of Lindvall’s paper, modified...that ~~~~~ < for all k1. The latter part of the condition perhaps needs some motivation. Suppose that a(X) is continuously differentiable , except

  5. The Effect of Circumferential Tube Wall Heat Conduction upon Laminar Filmwise Condensation on the Outside of Condenser Tubes.

    DTIC Science & Technology

    1980-12-01

    amount of tube surface area. Complications arise from these tubes, however, not the least being a sharp increase in the pumping power required to...V F. COMPARISON WITH PREVIOUS SOLUTIONS The aforementioned paper of Nicol, et al., [18] provided fertile ground for comparison, but only if the...000)-zz-jx’ - " C 4= LIUCW U )Lu L.U.QL&u.WWUI’ 40UJ. 0 C I (n .. Jte I- (�AJ~ ~ . LI. L I p~~~~~~~~~. 4. J.4.6~ i.~~ iui * ~ "W U~ - u . &LL.~ 4A

  6. Personal Flotation Devices Research. Volume 2. Research Report.

    DTIC Science & Technology

    1978-01-01

    C’-.J U. — — -~~~ C ‘- LUV 0 0 - .- C .- V N- U. C C - N- - C.) I I I I ) ‘ ~~ S _•. ~~~. C ~~ ‘.0 ~~ a- — SSO1 A~NVA011~ SONflOd V( A )- 32...test Is to preclude the approval of PFDs which deteriorate when subjected to a gasol i ne/ oil mi xture. A 20 to 1 , gas to oil ratio mi xture is Dre_...which does not have an oral inflation mechanism was subjected to 2 psi wi thout failure . All units passed the gas/ oil i mmersion and tensile test

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. National Dam Safety Program. Diascund Reservoir Dam. Inventory Number: VA-12703. New Kent County, Virginia. Phase I Inspection Report.

    DTIC Science & Technology

    1979-03-01

    iIIASQJII I ~SO~O1R I ~1Location: ~ r ~oi i ~air caurny, VII~INIA ~Inventory Number: VA .!:L.12703 1 - ,~ / ~ L~] PHASE I INSPECTION REPORT ‘ (9AT1ON...ak.lr.Sl sst tsd I ., MIoek 30. St ~~1l vwt ft... R p ert) - IS. SUPPLEMENTARY NOTES Copies are obtainable froB National Technica l Information...Service , Springfield , Virginia 22151 IL KEY BeRGS (C.” ~~ :. isua &~~ U 11 U4 SY i I ~~UU1)’ by block r ~~b.r) - Dam - VA National Darn Safety Program

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. Influencing Helmand: United States Marine Corps Operations in Helmand Province, Afghanistan, in 2008

    DTIC Science & Technology

    2010-04-14

    8217 Master of Military Studies Research Paper September 2009- April 2010 4. TITLE AND SUBTITLE Sa. CONTRACT NUMBER Influencing Helmand: United States...Staff College Marine Corps University 2076 South Street Marine Corps Combat Development Command Quantico, Virginia 22134-5068 MASTER OF MILITARY...THE REQUIREMENTS FOR THE DEGREE OF MASTER OF MILITARY STUDIES MAJOR SEAN DYNAN AY 09-10 Mentor and Or Approved:ti~~~~::.L~~~~~...,u

  6. 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.

  7. 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.

  8. A Survey of Fuel and Energy Information Sources: Volume II

    EPA Pesticide Factsheets

    ... con"",,, alld r~~i~~1' ,rl~'~~~i!~S' than who.ld Tau! ... I'ART of the year, plenoc fill out thio form. ... effect and na'ure of any impor- \\ant ware acale chanl ...

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. U.S. EPA, Pesticide Product Label, DEGESCH PHOSTOXIN PELLETS, 08/21/2006

    EPA Pesticide Factsheets

    2011-04-21

    ... o , t;~~ ." g ~ ~ .f§§ ., 8 !!: '" 0 lji " "H ' ~';"H~I'I " ~ ~~~ i~c~?? !~ P !l~'l . >, H I HHH ~!! ,,s ~ - , 8i itif~ i ~ ~:i!~ .J IHhi ZOO , ~!

  16. USSR Literature on Air Pollution and Related Occupational ...

    EPA Pesticide Factsheets

    ... On the basis of test results obtained with a model, a screen as described just above ... lf,F1TJ1~~ I / ~~1L .~ ~~ , I /',1 / I / / 2 7 3 6 5 12 II GI .D " -+' . II ...

  17. Model of Dredging Impact on Dungeness Crab in Grays Harbor, Washington

    DTIC Science & Technology

    1987-06-01

    Washington. 43 pp. Barry, Steve. 1986. Personal communication . Washington Dept. of Fisheries , Montesano, Washington. Bella, D.A. and K.J. Williamson. 1980... FISHERIES 18SHERIES RESEARCH INSTITUTE *~~ ~~~~~~~ Z *;r. .’."*,* U.-~0 SECURITY CLASSIFICATION OF THIS PAGE REPORT DOCUMENTATION PAGE Form Approved...School of Fisheries U.S.Ary Corps of Engineers, Seattle District 6c. ADDRESS (Cty, State, and ZIP Code) 7b. ADDRESS (City, State, and ZIP Code

  18. Dynamic Stall Computations Using a Zonal Navier-Stokes Model

    DTIC Science & Technology

    1988-06-01

    NAVAL POSTGRADUATE SCHOOL lotMonterey ,California CD Lj STATF ,-S THESIS DYNAMIC STALL CALCULATIONS USING A ZONAL.-,_ % 0 NVETESISDE by Jack H...Conroyd, Jr. June 1988 Thesis Co-advisors: M.F. Platzer Lawrence W. Carr Approved for public release; distribution is unlimitedDOTIC , ~~~~~~~~ELECT...OINT %, Master s Thesis OM To June 212 6 SLP;’LEENTARY NOTATION ri The views expressed in this thesis are those of the author and do not reflect the

  19. Individual Combatant’s Weapons Firing Algorithm Phase 1

    DTIC Science & Technology

    2010-06-01

    Z as in zebra...Drilis? 2 - 5 years ago More than 6 years ago 7. ~HOW~ z ~~:::: fire fights have you been In1 3-9 10 or more 8. Of those fights, what percentage were...34, ~ ’~-<’" ;-~/Nr,. ~ ~ "~t’ "X\\’ikJ ~ ,.’ \\1" ’: ’\\ Z ;J;l~~’i/’r.i\\ I " ,.. ..... ’-.-1 . , .. ,~ . \\\\ 1 ;C~"~~~~,~,, ~’",~"",~, ........... ~ f·

  20. The Coast Artillery Journal. Volume 81, Number 1, January-February 1938

    DTIC Science & Technology

    1938-02-01

    officers (at Cow Pens, Bemis Heights, Bunker Hill) be- GENERAL PHILIP KEARNY. By Thomas Kearnv . New York: G. P. Putnam’s Sons, 1937. 4~ pages; 19... Holstein , :: ~~~~:f;I~~1~i~~esSystems. D that shadowy and sinister figure in the Foreign Office who ft Starting Motors, Generators, and Lighting Systems...pulled the strings and made the incompetent imperial .. Theory of Internal CombustionEngines. :: chancellors dance. But Wilhelm knew of Holstein

  1. 4TH Mediterranean Workshop and Tropical Meeting "Novel Optical Materials and Applications" NOMA 99.

    DTIC Science & Technology

    1999-07-19

    If excitons have anharmonicity, the combination of large oscillator strength and the anharmonicity leads to large optical nonlinearity. Numerous...almost all NLO-polymers have a large optical loss compared with passive WG polymers. In these hybrid structures, only an active part for signal...quasi- phase matching based on chirality. I .::;~~~~~~~~a -: . .: 1 2 :: : , : •:•: :.?- ?i•;-•’’’::: .. AZOBENZENE POLYMERS FOR OPTICAL INFORMATION

  2. Gadolinium Scandium Gallium Garnet (GSGG) as a Solid-State Laser Host

    DTIC Science & Technology

    1987-07-01

    o*SATI CODSi1.SBEC EM (otne nrvrs fnceayad dniy nb)k ubr ~~~~~~~~ Gadolinium Scandium Gallium Garnet (GSGG)asaSldtteLerHt 17. ABSTRACT 6.SUJCTTEM...certain other garnet materials for replacement. It also addresses the solid-state laser host material Gadolinium Scandium Gal- lium Garnet (GSGG) and its...by neodymium-doped yttrium aluminum garnet (Nd:YAG) or other mate- rials for most applications. In the years after the invention of the ruby laser, in

  3. 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."

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. Simulators for Mariner Training and Licensing. Phase 1. The Role of Simulators in the Mariner Training and Licensing Process. Volume II.

    DTIC Science & Technology

    1980-07-01

    imidi NZN V) 0& TI ds003 LU- C- j Ito *AI~I om Qu N V V V V V CJ~ ~ ~~ INWOA~ illsVV VVV 2~SMUW~ d V V...WYIA N .3DC- 4 .*4N N SOMMIM C1 UW.!!0Ŗ N 141 A-4 AINI ’ SU W (4N ri N .., N 34M4 CD) ’T" J " D N f NdN Mau N 4 0-44 C~~~ d 2-NIINF LI AA-4 LL),~, rimi...SI-M L) J * Mcd d _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ I’d (A~~~~ ~~~ -IN svm~ d

  9. Ship Systems Staging Diagrams for DDG-37 Class Ships.

    DTIC Science & Technology

    1977-12-01

    progressing I 8 - _ _ - - - - I —-——- -- - - .4 — Drawing numbering — Material identification and ordering - — Pre-Overhaul Test and Inspection... DAMAGE CCNIROL 4CC NB t4—0C3 NIZZIE— MENI TC P TYPE N’) 64—004 NOZZI F— ~~AT FR QUENCH CA GA— MISCE LL~~NrouS G~~Cu~~S ( F L E X ) Oil 08— M JITIPLEX I~ AN...ICN A L INT ERLCC K .1 03 88—7 48 VALVE — P ILOT. PN~~ UMAT 1C CPERA TED 04 01— Gd PUM P—CFN TRI FUGA L . BOILER FEED 05 3 8 — 2 4 9 V A L V E — C O

  10. 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.

  11. 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.

  12. Mechanical Properties of Multi-Year Sea Ice. Phase 2. Test Results

    DTIC Science & Technology

    1985-10-01

    test3specimenstat spcd n tdVf-n plidsrs’ -20°Ct applied stess-iez mp era- aurs 10 4 1M -.......- . ..L . .. .. * t o’ -04% Stes lb/l t \\\\r "".% \\ . ~~~~~~~Figure

  13. 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.

  14. 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

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. U.S. EPA, Pesticide Product Label, , 01/12/1973

    EPA Pesticide Factsheets

    2011-04-21

    , #J ;j .i. I'; : I :l :. j :qJ $-J =':ITI'it j', ,~~ L;'tf1 T'J ;-~'tt"n : r~rf)\\ "l P"h,' ''' n 11:1" t'I'~ .,.y~ . ~ r; ~',, _ •.... f "",) . 1:' 'It(F.~~ ;~R f:!i ~~-'- ...

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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...

  6. 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

  7. A User’s Guide to CERC’s Field Research Facility.

    DTIC Science & Technology

    1981-10-01

    Fam,~ ~~~ 11 sIqldca Walter Mtlae iMi r,t Torrey Paintl le aceaec it Mattfmld and [att iv 1tera , Pi ,ot tloellI A’S’~ ~~ ~~ . n2K’t’ L trw: a ( Macha

  8. U.S. EPA, Pesticide Product Label, HERCON INSECTAPE HIGH-TECH WITH PROPOXUR, 03/26/1990

    EPA Pesticide Factsheets

    2011-04-21

    ... I 'I I , I --~J:c- - - . - i [] I~~~~il ['~~I (1 /~j ~;[rLp) AAA. Customer Interlace Cable Interface / f (1 I I I I I .. --- j 'I r-/ \\ , I,-c-' - f r t' '/ ,~J I ,r . ...

  9. U.S. EPA, Pesticide Product Label, , 07/13/1983

    EPA Pesticide Factsheets

    2011-04-21

    ... 1'1;. '. , Net \\ ight __ _ MIT ICI f!?G'~n~le-;':r~fo~?n~/~on~~~~a~e~le ·ELq\\VJ~~r t~ ttl{' F!·,~pr:tl In~f'('tj("idE'. Il'tmgicidi. i~.'l H(~!t'nti('id(· Act ...

  10. Laser Heating of Magnetically Confined Plasmas for X-Ray Production.

    DTIC Science & Technology

    1976-04-01

    self atsrm r~ t ion factor (SAF) is an arbitrary program input whose inverse PF2’ IFCT = SA F ’ mul t ip l ies Equation (3.25 ) to set a black body limit...from He-like neon to severa l MW. A detailed hydrodynamic and atomic physics program developed for this project— .~ ~~~ DD ~~~~~~~ 1473 I H I ’ I D...Sciences North- west , Inc . (MSNW) program for DNA , laser heating of magnetically con- fined plasma columns was demonstrated and moderate Z gases (neon

  11. The Mean vs Life-Limiting Fatigue Response of a Ni-Base Superalloy, Part 1: Mechanisms (Preprint)

    DTIC Science & Technology

    2008-09-01

    34’"L’\\" ~~·~~~:~~~?~i.. ~ ~I~~~.~.’ ,~.- .":_~ ••-:;’~.:-- 10JJITl 3 4 S 6 Grain diameter (",m) Figure 1: Microstructure of the INIOO...DATES COVERED (From - To) September 2008 Journal Article Preprint 4 . TITLE AND SUBTITLE THE MEAN VS LIFE-LIMITING FATIGUE RESPONSE OF A Ni-BASE...SUPERALLOY, PART 1: MECHANISMS (PREPRINT) 5a. CONTRACT NUMBER In-house 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62102F 6 . AUTHOR(S

  12. Skin Friction Measurements at a Mach Number of Three and Momentum Thickness Reynolds Numbers Up to a Half Million.

    DTIC Science & Technology

    1980-09-01

    k ADAOGZ 826 ~~~~~~~~~AIR FORCE FLIGHT DNMC A RGTPTESNABO / / I SKIN FRICTION MEASUREMENTS AT A MACH NUMBER OF THREE AND MOMENT--ETCIU) UNCASSFIE...AT A MACH NUMBER OF THREE AND MOMENTUM THICKNESS REYNOLDS NUMEERS UP TO A HALF MILLION Anthony W. Fiore Aeromechanics Division DTIC September 1980...NOR(&) S. CONTRACT OR GRANT NUMBER (s) 9. PER ORMING ORGANIZATION NAME AND ADDRESS PROR UNT N WU Flight Dynamics Laboratory (AFWAL/FIMG)RA; WOKUNTU

  13. On the Use of Framed Knowledge in Language Comprehension.

    DTIC Science & Technology

    1978-09-01

    knowledge In order to understand a certain stereotyped situation . We must , in other words , harmonize this idea with the opposite one of inodularhy. I...AD A Qb2 680 YAL E UNIV NEW HAVEN CONN DEPT OF cosPute. SCIENCE Fe’S 3/7 UNCLASSIFIED ON THE USE oc FRAMED KNOWLEDGE IN LANGUAGE COIflCHENSION.ftJ...DO JO? ~Jp~QDUC! L1GT3LY. ~~~~~~~~VERI# C) C.) w _ _ _ _ _ _ _ _ _ _ _ _ ON THE USE OF FRAMED KNOWLEDGE IN LANGUAGE COMPREHENSION Running t i t le

  14. Emergency Destruction of Information Storing Media

    DTIC Science & Technology

    1987-12-01

    22311-1772 IDA Log No. HO 86-30948 DEFINM~ONS IDA paMae Me folelwig isaes We inpu Me ed No WOOL Reput- Mr m ine uulas wd meet l aesbtmudirsil Prrel IDA...repelswpt plab ek iW bu atr* Weekeeie wwk. Papers e slee l urn Sd massdwAiedselaler le Sees apeatd rIlerA poperI@P I rsese jeereal. Munuruilum Reports...significantly from their commercial counterparts. 3 ................hr e a I~~~e~~~h ’ogy ~... ... .-.. /t : iii’~~i!:i~~i: ii"!: l : ... ............. l

  15. Intentions of Women (18-25 Years Old) to Join the Military: Results of a National Survey.

    DTIC Science & Technology

    1978-09-01

    MILITARY : RESULTS OF A NATIONAL SURVEY __________________________ S . PERFORMING ORG. N~PQRT NUMUER 7. Au fllON(.) S CONTRACT OR GRANT NUNSER(.) Jules...I. Borack S . PERFORMING ORGANI ZAtION N AME~~~~D ADDRE SS ~~~~. PRO GRAM ELEMENT. PROJECT. TaS~- AREA & WÔRK UNIT NUMSERS Navy Personnel Research and...non— Be interested in hiking. traditional women ’ s activities a- Marital status Be married . Be single. Financial Have financial responsibility Have no

  16. Antarctic Ice Charts 1989-1990

    DTIC Science & Technology

    1992-01-01

    DEVI-x ICNS -tXA kwk-q/z \\\\ I’ 3t i V o* 103m NORTHRN IC LIMI [O tI--Il 10 10 ;cl. ~~~~’-7 (X4 kAVA POLARW Ca NORAt CtNntR SUI A !2,,o i...8217 eW I / . 8 All - * N ’~ _X NV 2’j~St NS TAIA) - rh 4 ~ ~ ~~-..T SEA I / * p 4-~IC 1 / "lu$4----I / Nv ’~~T ’ A 7 IJLLIEDIOUCCD~cOYS //7 / ; n NOTHRAC

  17. 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 ...

  18. 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

  19. 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.

  20. 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.%.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Percutaneous penetration of silver from a silver containing garment in healthy volunteers and patients with atopic dermatitis.

    PubMed

    Pluut, Olivier A; Bianco, Carlotta; Jakasa, Ivone; Visser, Maaike J; Krystek, Petra; Larese-Filon, Francesca; Rustemeyer, Thomas; Kezic, Sanja

    2015-06-01

    Human data on dermal absorption of silver under "in use" scenario are scarce which hampers health risk assessment. The main objective of the present study was to determine percutaneous penetration of silver after dermal exposure to silver containing garment in healthy individuals and atopic dermatitis (AD) patients. Next to assess pro-inflammatory effect of silver in the skin. Healthy subjects (n=15) and patients with AD (n=15) wore a sleeve containing 3.6% (w/w) silver on their lower arms for 8h during 5 consecutive days. The percutaneous penetration parameters were deduced from the silver concentration-depth profiles in the stratum corneum (SC) collected by adhesive tapes. Furthermore, silver was measured in urine samples collected before and after exposure. Inflammatory response was assessed by measuring IL-1α and IL-1RA in the exposed and non-exposed skin sites. Dermal flux of silver in healthy subjects and AD patients was respectively 0.23 and 0.20 ng/cm(2)/h. The urine silver concentrations showed no increase after exposure. Furthermore, exposure to silver did not lead to the changes in the profiles of IL-1α and IL-1RA. Dermal absorption of silver under "real life scenario" was lower than the current reference dose. Furthermore, dermal exposure did not lead to altered expression of inflammatory IL-1 cytokines in the skin. Copyright © 2015. Published by Elsevier Ireland Ltd.

  10. Synthesis of water soluble glycine capped silver nanoparticles and their surface selective interaction

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

    Agasti, Nityananda, E-mail: nnagasti@gmail.com; Singh, Vinay K.; Kaushik, N.K.

    Highlights: • Synthesis of water soluble silver nanoparticles at ambient reaction conditions. • Glycine as stabilizing agent for silver nanoparticles. • Surface selective interaction of glycine with silver nanoparticles. • Glycine concentration influences crystalinity and optical property of silver nanoparticles. - Abstract: Synthesis of biocompatible metal nanoparticles has been an area of significant interest because of their wide range of applications. In the present study, we have successfully synthesized water soluble silver nanoparticles assisted by small amino acid glycine. The method is primarily based on reduction of AgNO{sub 3} with NaBH{sub 4} in aqueous solution under atmospheric air in themore » presence of glycine. UV–vis spectroscopy, transmission electron microscopy (TEM), X–ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetry (TG) and differential thermal analysis (DTA) techniques used for characterization of resulting silver nanoparticles demonstrated that, glycine is an effective capping agent to stabilize silver nanoparticles. Surface selective interaction of glycine on (1 1 1) face of silver nanoparticles has been investigated. The optical property and crystalline behavior of silver nanoparticles were found to be sensitive to concentration of glycine. X–ray diffraction studies ascertained the phase specific interaction of glycine on silver nanoparticles. Silver nanoparticles synthesized were of diameter 60 nm. We thus demonstrated an efficient synthetic method for synthesis of water soluble silver nanoparticles capped by amino acid under mild reaction conditions with excellent reproducibility.« less

  11. Engineered Escherichia coli Silver-Binding Periplasmic Protein That Promotes Silver Tolerance

    PubMed Central

    Hall Sedlak, Ruth; Hnilova, Marketa; Grosh, Carolynn; Fong, Hanson; Baneyx, Francois; Schwartz, Dan; Sarikaya, Mehmet; Tamerler, Candan

    2012-01-01

    Silver toxicity is a problem that microorganisms face in medical and environmental settings. Through exposure to silver compounds, some bacteria have adapted to growth in high concentrations of silver ions. Such adapted microbes may be dangerous as pathogens but, alternatively, could be potentially useful in nanomaterial-manufacturing applications. While naturally adapted isolates typically utilize efflux pumps to achieve metal resistance, we have engineered a silver-tolerant Escherichia coli strain by the use of a simple silver-binding peptide motif. A silver-binding peptide, AgBP2, was identified from a combinatorial display library and fused to the C terminus of the E. coli maltose-binding protein (MBP) to yield a silver-binding protein exhibiting nanomolar affinity for the metal. Growth experiments performed in the presence of silver nitrate showed that cells secreting MBP-AgBP2 into the periplasm exhibited silver tolerance in a batch culture, while those expressing a cytoplasmic version of the fusion protein or MBP alone did not. Transmission electron microscopy analysis of silver-tolerant cells revealed the presence of electron-dense silver nanoparticles. This is the first report of a specifically engineered metal-binding peptide exhibiting a strong in vivo phenotype, pointing toward a novel ability to manipulate bacterial interactions with heavy metals by the use of short and simple peptide motifs. Engineered metal-ion-tolerant microorganisms such as this E. coli strain could potentially be used in applications ranging from remediation to interrogation of biomolecule-metal interactions in vivo. PMID:22286990

  12. Governing factors affecting the impacts of silver nanoparticles on wastewater treatment.

    PubMed

    Zhang, Chiqian; Hu, Zhiqiang; Li, Ping; Gajaraj, Shashikanth

    2016-12-01

    Silver nanoparticles (nanosilver or AgNPs) enter municipal wastewater from various sources, raising concerns about their potential adverse effects on wastewater treatment processes. We argue that the biological effects of silver nanoparticles at environmentally realistic concentrations (μgL -1 or lower) on the performance of a full-scale municipal water resource recovery facility (WRRF) are minimal. Reactor configuration is a critical factor that reduces or even mutes the toxicity of silver nanoparticles towards wastewater microbes in a full-scale WRRF. Municipal sewage collection networks transform silver nanoparticles into silver(I)-complexes/precipitates with low ecotoxicity, and preliminary/primary treatment processes in front of biological treatment utilities partially remove silver nanoparticles to sludge. Microbial functional redundancy and microbial adaptability to silver nanoparticles also greatly alleviate the adverse effects of silver nanoparticles on the performance of a full-scale WRRF. Silver nanoparticles in a lab-scale bioreactor without a sewage collection system and/or a preliminary/primary treatment process, in contrast to being in a full scale system, may deteriorate the reactor performance at relatively high concentrations (e.g., mgL -1 levels or higher). However, in many cases, silver nanoparticles have minimal impacts on lab-scale bioreactors, such as sequencing batch bioreactors (SBRs), especially when at relatively low concentrations (e.g., less than 1mgL -1 ). The susceptibility of wastewater microbes to silver nanoparticles is species-specific. In general, silver nanoparticles have higher toxicity towards nitrifying bacteria than heterotrophic bacteria. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. U.S. EPA, Pesticide Product Label, PROPOXUR HOUSEHOLD INSECT RESIDUAL SPRAY 0.5%, 03/04/1981

    EPA Pesticide Factsheets

    2011-04-14

    ... l~l)1'o(IR rst: Ant !i-, ('~Liro.lCht."s.. ... r 1.-: .. t". ~ ( 1 ". ... rf 1 sh. s-.r~d".!~" 2!.PJE.tl.~, -"I-:;;-t~~'.th~~

  14. GRAS notice 733 for Purified steviol glycosides part 2

    Center for Food Safety and Applied Nutrition (CFSAN)

    ... d()..to. +.'LSl. ct ~ttJ!~~: D : \\ CH . EM32\\ l\\~ATA\\2 J l 6 ~ 09-~~;:1CG002;.o , 'r'\\CVV'I naa~~ .. L' t~ tw~ ~i. i..i./J(ti-. • "'t. c:i.tta.. P.«f pe4t. (J.~" ...

  15. Galvanic Corrosion Initiatives

    DTIC Science & Technology

    1987-12-01

    Blair, Incorporated Baldwin Tensile Tester, Model #472470, Southwark Division, Tate-Emery Company Extensometer, Model #P3M, Satec , Incorporated...8217%, , q% % A - 6.0" 3.0൉ -~ 4.0" .25"’ 2.0 tesl es pcme .Ř 3.00 B.~~~~~~ inuatn slee pee %, %. % Z-,P ENVIRONMENTS , The environments for this

  16. Glasgow AFB, Glasgow Montana. Revised Uniform Summary of Surface Weather Observations (RUSSWO). Parts A through F.

    DTIC Science & Technology

    1972-04-17

    TOTAL T TOTAL 3() 0 1.2 3 -4 5- 6 7-8 9.10 11-12113 14 15.16 17-18 19.20!21 22 23.24 252627 29729-30 It3 D.8. W.B.IO!, Bjb Wei BHI’D. P-1 46/ 4 r ri...8217 .+ ,+ ~~~~~~~~~~’ ’Y HH H’ ..++. . . .. .+’"+ " . . .J - - - DATA PROCESSING DIVISION USAF ITAC PSYCHROMETRIC SUMMARY2 AIR WEATHER SERVICE/MAC sT~ 3I5IO MATMAW YEARS...1019 3 jb @0017 01 ,6 0 12 ’Olo il 6 oil 4 0169 ,U1010tole4ioleg 103 SD 1.701.44 *9s ~@3 .051 50111,64 .*1~.14 .02 .70 9.1 ,01 ! TOTAL OAS 1 9, lotI! 1

  17. Prime Contractors with Awards Over $25,000 by Name, Location, and Contract Number, Fiscal Year 1992 (International Const. Co. Ltd.-McKay Communications)

    DTIC Science & Technology

    1993-01-01

    a4 a -- 0 a ,r 00 a.H Va CO u 0 0~ a. a . a 404~~ x- 4z. . . a a a. a~~~c. a WOw C6 Cr a D 00 - aa a a a3 a . Ca.~ ~ 0 acca rI a. az 0-. a 0 a 0 aD...4Ed V-4E ) F .4 ~ F 0.4 00. F4C n- F EL F: F3. xL O F-F,-.1~~~~F o)40 F en0 F (F 1. F 0 4 4 4 4 41 F6 F6 F8 a F6. 6 a 444~ F) 44 F) 4 0 4~~~ ccFF 0

  18. Determination of colloidal and dissolved silver in water samples using colorimetric solid-phase extraction.

    PubMed

    Hill, April A; Lipert, Robert J; Porter, Marc D

    2010-03-15

    The increase in bacterial resistance to antibiotics has led to resurgence in the use of silver as a biocidal agent in applications ranging from washing machine additives to the drinking water treatment system on the International Space Station (ISS). However, growing concerns about the possible toxicity of colloidal silver to bacteria, aquatic organisms and humans have led to recently issued regulations by the US EPA and FDA regarding the usage of silver. As part of an ongoing project, we have developed a rapid, simple method for determining total silver, both ionic (silver(I)) and colloidal, in 0.1-1mg/L aqueous samples, which spans the ISS potable water target of 0.3-0.5mg/L (total silver) and meets the US EPA limit of 0.1mg/L in drinking water. The method is based on colorimetric solid-phase extraction (C-SPE) and involves the extraction of silver(I) from water samples by passage through a solid-phase membrane impregnated with the colorimetric reagent DMABR (5-[4-(dimethylamino)benzylidene]rhodanine). Silver(I) exhaustively reacts with impregnated DMABR to form a colored compound, which is quantified using a handheld diffuse reflectance spectrophotometer. Total silver is determined by first passing the sample through a cartridge containing Oxone, which exhaustively oxidizes colloidal silver to dissolved silver(I). The method, which takes less than 2 min to complete and requires only approximately 1 mL of sample, has been validated through a series of tests, including a comparison with the ICP-MS analysis of a water sample from ISS that contained both silver(I) and colloidal silver. Potential earth-bound applications are also briefly discussed. Copyright (c) 2009 Elsevier B.V. All rights reserved.

  19. Oxidative stress mediated cytotoxicity of biologically synthesized silver nanoparticles in human lung epithelial adenocarcinoma cell line

    NASA Astrophysics Data System (ADS)

    Han, Jae Woong; Gurunathan, Sangiliyandi; Jeong, Jae-Kyo; Choi, Yun-Jung; Kwon, Deug-Nam; Park, Jin-Ki; Kim, Jin-Hoi

    2014-09-01

    The goal of the present study was to investigate the toxicity of biologically prepared small size of silver nanoparticles in human lung epithelial adenocarcinoma cells A549. Herein, we describe a facile method for the synthesis of silver nanoparticles by treating the supernatant from a culture of Escherichia coli with silver nitrate . The formation of silver nanoparticles was characterized using various analytical techniques. The results from UV-visible (UV-vis) spectroscopy and X-ray diffraction analysis show a characteristic strong resonance centered at 420 nm and a single crystalline nature, respectively. Fourier transform infrared spectroscopy confirmed the possible bio-molecules responsible for the reduction of silver from silver nitrate into nanoparticles. The particle size analyzer and transmission electron microscopy results suggest that silver nanoparticles are spherical in shape with an average diameter of 15 nm. The results derived from in vitro studies showed a concentration-dependent decrease in cell viability when A549 cells were exposed to silver nanoparticles. This decrease in cell viability corresponded to increased leakage of lactate dehydrogenase (LDH), increased intracellular reactive oxygen species generation (ROS), and decreased mitochondrial transmembrane potential (MTP). Furthermore, uptake and intracellular localization of silver nanoparticles were observed and were accompanied by accumulation of autophagosomes and autolysosomes in A549 cells. The results indicate that silver nanoparticles play a significant role in apoptosis. Interestingly, biologically synthesized silver nanoparticles showed more potent cytotoxicity at the concentrations tested compared to that shown by chemically synthesized silver nanoparticles. Therefore, our results demonstrated that human lung epithelial A549 cells could provide a valuable model to assess the cytotoxicity of silver nanoparticles.

  20. Evaluation of bactericidal efficacy of silver ions on Escherichia coli for drinking water disinfection.

    PubMed

    Pathak, Satya P; Gopal, K

    2012-07-01

    The purpose of this study is the development of a suitable process for the disinfection of drinking water by evaluating bactericidal efficacy of silver ions from silver electrodes. A prototype of a silver ioniser with silver electrodes and control unit has been fabricated. Silver ions from silver electrodes in water samples were estimated with an atomic absorption spectrophotometer. A fresh culture of Escherichia coli (1.75 × 10(3) c.f.u./ml) was exposed to 1, 2, 5, 10 and 20 ppb of silver ions in 100 ml of autoclaved tap water for 60 min. The effect of different pH and temperatures on bactericidal efficacy was observed at constant silver ion concentration (5 ppb) and contact time of 30 min. The maximum bactericidal activity (100%) was observed at 20 ppb of silver ion concentration indicating total disinfection after 20 min while minimum bactericidal activity (25%) was observed after 10 min at 01 ppb of silver ions. Likewise, 100% bactericidal activity was noticed with 2, 5 and 10 ppb of silver ions after 60, 50 and 40 min, respectively. Bactericidal activity at pH 5, 6, 7, 8 and 9 was observed at 79.9%, 79.8%, 80.5%, 100% and 100%, respectively, whereas it was 80.4%, 88.3%, 100%, 100% and 100% at 10°C, 20°C, 30°C, 40°C and 50°C, respectively. The findings of this study revealed that very low concentrations of silver ions at pH 8-9 and temperature >20°C have bactericidal efficacy for total disinfection of drinking water. Silver ionisation is suitable for water disinfection and an appropriate alternative to chlorination which forms carcinogenic disinfection by-products.

  1. Oxidative stress mediated cytotoxicity of biologically synthesized silver nanoparticles in human lung epithelial adenocarcinoma cell line

    PubMed Central

    2014-01-01

    The goal of the present study was to investigate the toxicity of biologically prepared small size of silver nanoparticles in human lung epithelial adenocarcinoma cells A549. Herein, we describe a facile method for the synthesis of silver nanoparticles by treating the supernatant from a culture of Escherichia coli with silver nitrate. The formation of silver nanoparticles was characterized using various analytical techniques. The results from UV-visible (UV-vis) spectroscopy and X-ray diffraction analysis show a characteristic strong resonance centered at 420 nm and a single crystalline nature, respectively. Fourier transform infrared spectroscopy confirmed the possible bio-molecules responsible for the reduction of silver from silver nitrate into nanoparticles. The particle size analyzer and transmission electron microscopy results suggest that silver nanoparticles are spherical in shape with an average diameter of 15 nm. The results derived from in vitro studies showed a concentration-dependent decrease in cell viability when A549 cells were exposed to silver nanoparticles. This decrease in cell viability corresponded to increased leakage of lactate dehydrogenase (LDH), increased intracellular reactive oxygen species generation (ROS), and decreased mitochondrial transmembrane potential (MTP). Furthermore, uptake and intracellular localization of silver nanoparticles were observed and were accompanied by accumulation of autophagosomes and autolysosomes in A549 cells. The results indicate that silver nanoparticles play a significant role in apoptosis. Interestingly, biologically synthesized silver nanoparticles showed more potent cytotoxicity at the concentrations tested compared to that shown by chemically synthesized silver nanoparticles. Therefore, our results demonstrated that human lung epithelial A549 cells could provide a valuable model to assess the cytotoxicity of silver nanoparticles. PMID:25242904

  2. Hydrographic and Ecological Effects of Enlargement of the Chesapeake and Delaware Canal. Appendix IV. Benthos of Delaware Waters in and Near C and D Canal.

    DTIC Science & Technology

    1973-09-01

    stations in the last three sampling periods of this project to supplement the regular I infaunal sampling schedule. Salinity , dissolved oxygen, water...summer. Salinity was quite variable but tended to be * highest in late summer (range 0.1 — 10 O/~~~~~~ )~~~ Dissolved oxygen, being an inverse...function of both salinity and temperature, dropped in summer. Concentrations in the 2—3 mg/l range were not unusual. The physical data collected in

  3. An Evaluation of Four MTS Recurrent Training Courses,

    DTIC Science & Technology

    1978-09-01

    management—by— objectives and team action . The evaluation of each of these four recurrent training courses follows the general approach taken in the earlier...D AU bI 519 FEant AVIATION ADMINISTRATION IflHINSTON 0 C OFFICE—ETC P/S 5/9AN EVALUATION Of FOJR MIS RECURRENT TRAIN ING C OURSES. (U)SEP 78 R C S M...Sep -~-__ L.__ T)78 ~. L I AN E VALUAT ION OF FOUR MTS RE CURRE NT TRAINING COURSESi —fl. - -— .-.~~. ..~~~~~~~ ‘ ) 6. erfo,a,~ng OrgoniZotro~I Cod

  4. Human Factors Affecting Pilot Performance in Vertical and Translational Instrument Flight.

    DTIC Science & Technology

    1983-12-01

    measures. DD I 1473 EDITION OF I NOV SS 0WITI UnclassifiedS’N 002-L-014-601 d Mhoi~~ ~~~~~~~ SEUIYCASFCAINO HSP BEHAVORAL ENGINEERING LABORATORY e.-)(Co...Dr. A. L. Slafkosky Mr. R. Lawson Scientific Advisor ONR Detachment Commandant of the Marine Corps 1030 East Green Street Code RD-i SPasadena, CA 91106...Center ONR Detachment Orlando, FL 32b13 1030 East Green Street3. Pasadena, CA 911u6 CDR INouiian ’L. Lane Code N-7A Naval Training Equipment Center

  5. National Dam Safety Program. Memphis Lake and Park Dam (MO 10217), Mississippi - SAlt - Quincy River Basin, Scotland County, Missouri. Phase I Inspection Report.

    DTIC Science & Technology

    1978-12-01

    91 ._ ,_ ., o .2 2’. 3 bl.37 . . . . . ... A.7 ,,?Y 33 Y3,1 . . ... 9. .. . Q . o 7 .,/1 281 .l5/ . . . . - 3,c~ 2,542 3 1 2/6J ? 11,3 ),o ! ,os’ /,.3...8217;.;, ." ;,; - . . .CCC14, , .,.. . - ,fl qk -- I a4 . zWI & a a la Ir Z 0 f 1. ; ata d *~~~~~~~~~0D O 7 ... . . . . . .. . . . . . - AS 1 Z. Zt ~40. 4 0 . & J,10" 1

  6. Software Dependability Assessment Methods.

    DTIC Science & Technology

    1986-11-01

    Maor.rldx TABLE ~~~~~~ ~ ~ .2.RVU OFWR ETBI1YMDL Goei Crot~Nor~ Nu wu.. Ps.~o, r1.~~j% 2-4 __ N App L,-caW L Nct A pp.cLL tc ReAAW -Ur e ’-cdtl L. Reaons I...bug is found and immediately removed. The model provides a good fit with data. The parameter estimates are reasonable for the data sets tested. 3.0...where n = the number of errors found to date. 6.3 Study Results The model provides a good fit with data. The model runs into slight trouble with its "no

  7. Disadvantages and Advantages of Sewage Disposal in Connection with Agricultural Utilization (Wady i Zalety Oczyszczania wod Sciekowych w Polaczeniv Zoich Rolnicyzm Wykorzystaniem),

    DTIC Science & Technology

    1977-09-01

    A b—AO ’ le 767 CO4.D REGIONS RESEARCH APt ENSINEERINS LAS HANOVCR N H F/S 13/2DISADVANTAGES AND ADVANTAGES OF SEWAGE DISPOSAL IN COP*IECTI0N W...DISADVANTAGES AND ADVANTAGES OF SEWA GE DISPOSAL IN CONNECTION WITH A GRICULTURAL UTILIZATION J. W i e r z b ick i >- C-) u-iI...significant economic advantages dictates the widest possible appli- cation of land treatment of sewage purification. DO , ~~~~~~~~~ ‘ ,., 1473 COITI ON OF I

  8. U. S. Civil Airmen Statistics.

    DTIC Science & Technology

    1976-01-01

    25, 44 9 , 2 ,2 Sa 27 , ’ n Ci Un C ted Sta ten”total , 3OIL.J038 U35,V,3,91 l,,s.4_ ‘.4 11.7 ‘n,,’iJ~, U.L,,i2 ~~~~ ~~~~~ New Eo g l a n d .— t...Me xiCo 1 ,717 88S 78 (401 (2 9 5 5 3 V s Arkansas 5 ,666 865 61 (425 5 “ C S 9 CC R ocky Mou flt wun .”total - - ‘ L,1iI 0.019 53~, la,12n4

  9. The Evaluation and Systems Analysis of the SYSTRAN Machine Translation System

    DTIC Science & Technology

    1977-01-01

    DiFondi (IRDT) I. KIY *0*01 (Cu.wMu. .~ .‘~~.. lid. it a....Wp .11 id.iiSiIp Op e4.Sk s~~S.,) Machine Traca lation Evaluation scan Dictionary Update S...ntic Expression Dictionary Update *55? **Ct fCMi~ uw * lid. It -- p Sdsffl~~ Sr Sidsi ,~~~Siv) This report is the product of contractual effort to...translated end then corrected by a b ilingu.ai. exper t in each field. two types of corrections were considered iaplweatabi e, stan dictionary update and

  10. A Pharmacological and Toxicological Profile of Silver as an Antimicrobial Agent in Medical Devices

    PubMed Central

    Lansdown, Alan B. G.

    2010-01-01

    Silver is used widely in wound dressings and medical devices as a broad-spectrum antibiotic. Metallic silver and most inorganic silver compounds ionise in moisture, body fluids, and secretions to release biologically active Ag+. The ion is absorbed into the systemic circulation from the diet and drinking water, by inhalation and through intraparenteral administration. Percutaneous absorption of Ag+ through intact or damaged skin is low. Ag+ binds strongly to metallothionein, albumins, and macroglobulins and is metabolised to all tissues other than the brain and the central nervous system. Silver sulphide or silver selenide precipitates, bound lysosomally in soft tissues, are inert and not associated with an irreversible toxic change. Argyria and argyrosis are the principle effects associated with heavy deposition of insoluble silver precipitates in the dermis and cornea/conjunctiva. Whilst these changes may be profoundly disfiguring and persistent, they are not associated with pathological damage in any tissue. The present paper discusses the mechanisms of absorption and metabolism of silver in the human body, presumed mechanisms of argyria and argyrosis, and the elimination of silver-protein complexes in the bile and urine. Minimum blood silver levels consistent with early signs of argyria or argyrosis are not known. Silver allergy does occur but the extent of the problem is not known. Reference values for silver exposure are discussed. PMID:21188244

  11. Leaching of Silver from Silver-Impregnated Food Storage Containers

    ERIC Educational Resources Information Center

    Hauri, James F.; Niece, Brian K.

    2011-01-01

    The use of silver in commercial products has proliferated in recent years owing to its antibacterial properties. Food containers impregnated with micro-sized silver promise long food life, but there is some concern because silver can leach out of the plastic and into the stored food. This laboratory experiment gives students the opportunity to…

  12. Rethinking Schools and the Power of Silver

    ERIC Educational Resources Information Center

    Sleeter, Christine

    2011-01-01

    This 25th anniversary of "Rethinking Schools" can be thought of as its silver anniversary. Silver itself must be considered through contrasting lenses. On the one hand, as lessons in "Rethinking Globalization" teach, silver and gold were the basis of Europe's horrendous exploitation of Latin America. On the other hand, silver is often associated…

  13. Biomimetics of silver nanoparticles by white rot fungus, Phaenerochaete chrysosporium.

    PubMed

    Vigneshwaran, Nadanathangam; Kathe, Arati A; Varadarajan, P V; Nachane, Rajan P; Balasubramanya, R H

    2006-11-01

    Extracellular synthesis of silver nanoparticles by a white rot fungus, Phaenerochaete chrysosporium is reported in this paper. Incubation of P. chrysosporium mycelium with silver nitrate solution produced silver nanoparticles in 24h. These silver nanoparticles were characterized by means of UV-vis spectroscopy, X-ray diffraction analysis, scanning electron microscopy, transmission electron microscopy, and photoluminescence spectroscopy. The synthesized silver nanoparticles absorbed maximum at 470 nm in the visible region. XRD spectrum of the silver nanoparticles confirmed the formation of metallic silver. The SEM characterization of the fungus reacted on the Ag+ indicated that the protein might be responsible for the stabilization of silver nanoparticles. This result was further supported by the TEM examination. Though shape variation was noticed, majority of the nanoparticles were found to be of pyramidal shape as seen under TEM. Photoluminescence spectrum showed a broad emission peak of silver nanoparticles at 423 nm when excited at 350 nm. Apart from eco-friendliness, fungus as bio-manufacturing unit will give us an added advantage in ease of handling when compared to other classes of microorganisms.

  14. Procedure optimization for green synthesis of silver nanoparticles by aqueous extract of Eucalyptus oleosa.

    PubMed

    Pourmortazavi, Seied Mahdi; Taghdiri, Mehdi; Makari, Vajihe; Rahimi-Nasrabadi, Mehdi

    2015-02-05

    The present study is dealing with the green synthesis of silver nanoparticles using the aqueous extract of Eucalyptus oleosa as a green synthesis procedure without any catalyst, template or surfactant. Colloidal silver nanoparticles were synthesized by reacting aqueous AgNO3 with E. oleosa leaf extract at non-photomediated conditions. The significance of some synthesis conditions such as: silver nitrate concentration, concentration of the plant extract, time of synthesis reaction and temperature of plant extraction procedure on the particle size of synthesized silver particles was investigated and optimized. The participations of the studied factors in controlling the particle size of reduced silver were quantitatively evaluated via analysis of variance (ANOVA). The results of this investigation showed that silver nanoparticles could be synthesized by tuning significant parameters, while performing the synthesis procedure at optimum conditions leads to form silver nanoparticles with 21nm as averaged size. Ultraviolet-visible spectroscopy was used to monitor the development of silver nanoparticles formation. Meanwhile, produced silver nanoparticles were characterized by scanning electron microscopy, energy-dispersive X-ray, and FT-IR techniques. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Capsaicin-capped silver nanoparticles: its kinetics, characterization and biocompatibility assay

    NASA Astrophysics Data System (ADS)

    Amruthraj, Nagoth Joseph; Preetam Raj, John Poonga; Lebel, Antoine

    2015-04-01

    Capsaicin was used as a bio-reductant for the reduction of silver nitrate to form silver nanoparticles. The formation of the silver nanoparticles was initially confirmed by color change and Tyndall effect of light scattering. It was characterized with UV-visible spectroscopy, FTIR and TEM. Hemagglutination (H) test and H-inhibition assay were performed in the presence of AgNPs-capsaicin conjugates. The silver colloid solution after complete reduction turned into pale gray color. The characteristic surface plasmon resonance of silver nanoparticles (SNPs) was observed at 450 nm. Time taken for complete bio-reduction of silver nitrate and capping was found to be 16 hours. The amount of capsaicin required to reduce 20 ml of 1 mM silver nitrate solution was found to be 40 μg approximately. The FTIR results confirmed the capping of capsaicin on the silver metal. The particle size was within the range of 20-30 nm. The hemagglutination and H-inhibition test was negative for all the blood groups. The capsaicin-capped silver nanoparticles were compatible with blood cells in hemagglutination test implying biocompatibility as future therapeutic drug.

  16. The antifungal effect of silver nanoparticles on Trichosporon asahii.

    PubMed

    Xia, Zhi-Kuan; Ma, Qiu-Hua; Li, Shu-Yi; Zhang, De-Quan; Cong, Lin; Tian, Yan-Li; Yang, Rong-Ya

    2016-04-01

    Silver nanoparticles are receiving increasing attention in biomedical applications. This study aims at evaluating the antifungal properties of silver nanoparticles against the pathogenic fungus Trichosporon asahii. The growth of T. asahii on potato dextrose agar medium containing different concentrations of silver nanoparticles was examined and the antifungal effect was evaluated using minimum inhibitory concentration. Scanning and transmission electron microscopy were also used to investigate the antifungal effect of silver nanoparticles on T. asahii. Silver nanoparticles had a significant inhibitory effect on the growth of T. asahii. The minimum inhibitory concentration of silver nanoparticles against T. asahii was 0.5 μg/mL, which was lower than amphotericin B, 5-flucytosine, caspofungin, terbinafine, fluconazole, and itraconazole and higher than voriconazole. Silver nanoparticles obviously damaged the cell wall, cell membrane, mitochondria, chromatin, and ribosome. Our results demonstrate that silver nanoparticles have good antifungal activity against T. asahii. Based on our electron microscopy observations, silver nanoparticles may inhibit the growth of T. asahii by permeating the fungal cell and damaging the cell wall and cellular components. Copyright © 2014. Published by Elsevier B.V.

  17. U.S. EPA, Pesticides, Label, MAQUAT 2420-CITRUS, 12/16/2010

    EPA Pesticide Factsheets

    2011-04-13

    ... 8. i[(AJresh{scjltlti.6:n:··mbst;,~~:prepa.~~d)!(p,repareia;fre~h;i?Q!uJi..QQ)]· atiIEt~§@~II~:orwJ:i~D lLJ~t~J;()II;J!iql'lib~..f~rtf ... 9r trigg~r:~PI~y.~~e:\\fic .. ...

  18. Proper Procedures for Use and Adjustment of the Survey Sextant.

    DTIC Science & Technology

    1978-07-01

    A N D M A R K I I ‘~— — — — — — — — — — — — — — — p ~~ 11’ FIGURE M . S~~RVl;y SEXT .\\~~ wiTu ‘n:n P’US’~ IN ADJL’ST POSITION. Thelight beams sh

  19. Synthesis and characterization of monodispersed silver nanoparticles

    NASA Astrophysics Data System (ADS)

    Jegatha Christy, A.; Umadevi, M.

    2012-09-01

    Synthesis of silver nanoparticles (NPs) has become a fascinating and important field of applied chemical research. In this paper silver NPs were prepared using silver nitrate (AgNO3), gelatin, and cetyl trimethyl ammonium bromide (CTAB). The prepared silver NPs were exposed under the laser ablation. In our photochemical procedure, gelatin acts as a biopolymer and CTAB acts as a reducing agent. The appearance of surface plasmon band around 410 nm indicates the formation of silver NPs. The nature of the prepared silver NPs in the face-centered cubic (fcc) structure are confirmed by the peaks in the x-ray diffraction (XRD) pattern corresponding to (111), (200), (220) and (311) planes. Monodispersed, stable, spherical silver NPs with diameter about 10 nm were obtained and confirmed by high-resolution transmission electron microscope (HRTEM).

  20. Synthesis of Silver Polymer Nanocomposites and Their Antibacterial Activity

    NASA Astrophysics Data System (ADS)

    Gavade, Chaitali; Shah, Sunil; Singh, N. L.

    2011-07-01

    PVA (Polyvinyl Alcohol) silver nanocomposites of different sizes were prepared by chemical reduction method. Silver nitrate was taken as the metal precursor and amine hydrazine as a reducing agent. The formation of the silver nanoparticles was noticed using UV- visible absorption spectroscopy. The UV-visible spectroscopy revealed the formation of silver nanoparticles by exhibiting the surface plasmon resonance. The bactericidal activity due to silver release from the surface was determined by the modification of conventional diffusion method. Salmonella typhimurium, Serratia sps and Shigella sps were used as test bacteria which are gram-negative type bacteria. Effect of the different sizes of silver nano particles on antibacterial efficiency was discussed. Zones of inhibition were measured after 24 hours of incubation at 37 °C which gave 20 mm radius for high concentration of silver nanoparticles.

  1. Nuclear radiation-warning detector that measures impedance

    DOEpatents

    Savignac, Noel Felix; Gomez, Leo S; Yelton, William Graham; Robinson, Alex; Limmer, Steven

    2013-06-04

    This invention is a nuclear radiation-warning detector that measures impedance of silver-silver halide on an interdigitated electrode to detect light or radiation comprised of alpha particles, beta particles, gamma rays, X rays, and/or neutrons. The detector is comprised of an interdigitated electrode covered by a layer of silver halide. After exposure to alpha particles, beta particles, X rays, gamma rays, neutron radiation, or light, the silver halide is reduced to silver in the presence of a reducing solution. The change from the high electrical resistance (impedance) of silver halide to the low resistance of silver provides the radiation warning that detected radiation levels exceed a predetermined radiation dose threshold.

  2. Characterization of silver nanoparticles synthesized using an endophytic fungus, Penicillium oxalicum having potential antimicrobial activity

    NASA Astrophysics Data System (ADS)

    Bhattacharjee, Sukla; Debnath, Gopal; Das, Aparajita Roy; Krishna Saha, Ajay; Das, Panna

    2017-12-01

    The aim of the present study was to test the efficacy of the extracellular mycelium extract of Penicillium oxalicum isolated from Phlogacanthus thyrsiflorus to biosynthesize silver nanoparticles. It was characterized using ultraviolet-visible absorption spectroscopy, atomic force microscopy, transmission electron microscopy and Fourier transforms infrared spectroscopy. The silver nanoparticles were evaluated for antimicrobial activity. The characterization confirms the synthesis of silver nanoparticles. Both silver nanoparticles and combination of silver nanoparticles with streptomycin showed activity against the four bacteria. The results suggested that P. oxalicum offers eco-friendly production of silver nanoparticles and the antibacterial activity may find application in biomedicine.

  3. Determination of traces of silver in waters by anion exchange and atomic absorption spectrophotometry

    USGS Publications Warehouse

    Chao, T.T.; Fishman, M. J.; Ball, J.W.

    1969-01-01

    A method has been developed for the accurate determination of 0.1-1 ??g of silver per liter of water. The method permits stabilization of silver in water without loss to container walls. Optimum conditions have been established for the complete recovery of silver from water with an anion-exchange column, for quantitative elution of silver from the resin, and for measurement of silver by atomic absorption spectrophotometry after chelation with ammonium pyrrolidine dithiocarbamate and extraction of the chelate with MIBK. Silver in the 1-10 ??g 1 range can be determined by extraction without pre-concentration on an ion-exchange resin. ?? 1969.

  4. Mineral commodity profiles: Silver

    USGS Publications Warehouse

    Butterman, W.C.; Hilliard, Henry E.

    2005-01-01

    Overview -- Silver is one of the eight precious, or noble, metals; the others are gold and the six platinum-group metals (PGM). World mine production in 2001 was 18,700 metric tons (t) and came from mines in 60 countries; the 10 leading producing countries accounted for 86 percent of the total. The largest producer was Mexico, followed by Peru, Australia, and the United States. About 25 percent of the silver mined in the world in 2001 came from silver ores; 15 percent, from gold ores and the remaining 60 percent, from copper, lead, and zinc ores. In the United States, 14 percent of the silver mined in 2001 came from silver ores; 39 percent, from gold ores; 10 percent, from copper and copper-molybdenum ores; and 37 percent, from lead, zinc, and lead-zinc ores. The precious metal ores (gold and silver) came from 30 lode mines and 10 placer mines; the base-metal ores (copper, lead, molybdenum, and zinc) came from 24 lode mines. Placer mines yielded less than 1 percent of the national silver production. Silver was mined in 12 States, of which Nevada was by far the largest producer; it accounted for nearly one-third of the national total. The production of silver at domestic mines generated employment for about 1,100 mine and mill workers. The value of mined domestic silver was estimated to be $290 million. Of the nearly 27,000 t of world silver that was fabricated in 2001, about one-third went into jewelry and silverware, one-fourth into the light-sensitive compounds used in photography, and nearly all the remainder went for industrial uses, of which there were 7 substantial uses and many other small-volume uses. By comparison, 85 percent of the silver used in the United States went to photography and industrial uses, 8 percent to jewelry and silverware, and 7 percent to coins and medals. The United States was the largest consumer of silver followed by India, Japan, and Italy; the 13 largest consuming countries accounted for nearly 90 percent of the world total. In the United States, about 30 companies accounted for more than 90 percent of the silver fabricated. The consumption of silver for all fabrication uses is expected to grow slowly through the decade ending in 2010 at about 1.3 percent per year for the world and 2.4 percent per year for the United States. World and U.S. reserves and reserve bases are more than adequate to satisfy the demand for newly mined silver through 2010. The other components of supply will be silver recovered from scrap, silver from industrial stocks, and silver bullion that is sold into the market from commodity exchange and private stocks.

  5. Effect of preconditioning on silver leaching and bromide removal properties of silver-impregnated activated carbon (SIAC).

    PubMed

    Rajaeian, Babak; Allard, Sébastien; Joll, Cynthia; Heitz, Anna

    2018-07-01

    Silver impregnated activated carbon (SIAC) has been found to be effective in mitigating the formation of brominated-disinfection by products during drinking water treatment. However, there are still uncertainties regarding its silver leaching properties, and strategies for the prevention of silver leaching have remained elusive. This study focused on the evaluation of one type of commercially available SIAC for its ability to remove bromide while minimising silver leaching from the material. Both synthetic and real water matrices were tested. Depending on solution pH, it was found that changing the surface charge properties of SIAC, as measured by the point of zero charge pH, can result in additional bromide removal while minimising the extent of silver leaching. To better understand the mechanism of silver leaching from the SIAC, eight preconditioning environments, i.e. variable pH and ionic strength were tested for a fixed amount of SIAC and two preconditioning environments were selected for a more detailed investigation. Experiments carried out in synthetic water showed that preconditioning at pH 10.4 did not deteriorate the capacity of SIAC to remove bromide, but significantly decreased the release of silver in the form of ionic silver (Ag + ), silver bromide (AgBr) and silver chloride (AgCl) from 40% for the pristine to 3% for the treated SIAC. This was confirmed using a groundwater sample. These results suggest that preconditioned SIAC has the potential to be an effective method for bromide removal with minimised silver leaching in a long-term field application for drinking water production. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. A re-assessment of the safety of silver in household water treatment: rapid systematic review of mammalian in vivo genotoxicity studies.

    PubMed

    Fewtrell, Lorna; Majuru, Batsirai; Hunter, Paul R

    2017-06-20

    Despite poor evidence of their effectiveness, colloidal silver and silver nanoparticles are increasingly being promoted for treating potentially contaminated drinking water in low income countries. Recently, however, concerns have been raised about the possible genotoxicity of particulate silver. The goal of this paper was to review the published mammalian in vivo genotoxicity studies using silver micro and nanoparticles. SCOPUS and Medline were searched using the following search string: ("DNA damage" OR genotox* OR Cytotox* OR Embryotox*) AND (silver OR AgNP). Included papers were any mammalian in vivo experimental studies investigating genotoxicity of silver particles. Studies were quality assessed using the ToxRTool. 16 relevant papers were identified. There were substantial variations in study design including the size of silver particles, animal species, target organs, silver dose, route of administration and the method used to detect genotoxicity. Thus, it was not possible to produce a definitive pooled result. Nevertheless, most studies showed evidence of genotoxicity unless using very low doses. We also identified one human study reporting evidence of "severe DNA damage" in silver jewellery workers occupationally exposed to silver particles. With the available evidence it is not possible to be definitive about risks to human health from oral exposure to silver particulates. However, the balance of evidence suggests that there should be concerns especially when considering the evidence from jewellery workers. There is an urgent need to determine whether people exposed to particulate silver as part of drinking water treatment have evidence of DNA damage.

  7. Development of the rectal dosage form with silver-coated glass beads for local-action applications in lower sections of the gastrointestinal tract.

    PubMed

    Siczek, Krzysztof; Fichna, Jakub; Zatorski, Hubert; Karolewicz, Bożena; Klimek, Leszek; Owczarek, Artur

    2018-03-01

    Recent findings indicating the anti-inflammatory action of silver preparations through modulation of the gut microbiota and apoptosis of inflammatory cells predestine silver use in inflammatory bowel disease (IBD). The aim of our study was to validate the possibility of effective silver release from silver-coated glass beads for anti-inflammatory local application in the lower sections of the gastrointestinal (GI) tract. Silver-coated glass beads were prepared using magnetron method. Release of silver from the silver-coated glass bead surface was carried out in BIO-DIS reciprocating cylinder apparatus. Erosion of silver coating and indirect estimation of the silver release dynamics was assessed using scanning electron microscope. Rectal suppositories containing silver-coated glass beads were prepared using five different methods (M1-M5) and X-ray scanned for their composition. The XR microanalysis and the chemical composition analysis evidenced for a rapid (within 30 min) release of nearly 50% of silver from the coating of the glass beads, which remained stable up to 24 h of incubation. The most homogeneous distribution of beads in the entire volume of the suppository was obtained for formulation M5, where the molten base was poured into mold placed in an ice bath, and the beads were added after 10 s. Our study is the first to present the concept of enclosing silver-coated glass beads in the lipophilic suppository base to attenuate inflammation in the lower GI tract and promises efficient treatment with reduced side effects.

  8. Evolution of silver nanoparticles in the rat lung investigated by X-ray absorption spectroscopy

    DOE PAGES

    Davidson, R. Andrew; Anderson, Donald S.; Van Winkle, Laura S.; ...

    2014-12-16

    Following a 6-h inhalation exposure to aerosolized 20 and 110 nm diameter silver nanoparticles, lung tissues from rats were investigated with X-ray absorption spectroscopy, which can identify the chemical state of silver species. Lung tissues were processed immediately after sacrifice of the animals at 0, 1, 3, and 7 days post exposure and the samples were stored in an inert and low-temperature environment until measured. We found that it is critical to follow a proper processing, storage and measurement protocol; otherwise only silver oxides are detected after inhalation even for the larger nanoparticles. The results of X-ray absorption spectroscopy measurementsmore » taken in air at 85 K suggest that the dominating silver species in all the postexposure lung tissues were metallic silver, not silver oxide, or solvated silver cations. The results further indicate that the silver nanoparticles in the tissues were transformed from the original nanoparticles to other forms of metallic silver nanomaterials and the rate of this transformation depended on the size of the original nanoparticles. Furthermore, we found that 20 nm diameter silver nanoparticles were significantly modified after aerosolization and 6-h inhalation/deposition, whereas larger, 110 nm diameter nanoparticles were largely unchanged. Over the seven-day postexposure period the smaller 20 nm silver nanoparticles underwent less change in the lung tissue than the larger 110 nm silver nanoparticles. In contrast, silica-coated gold nanoparticles did not undergo any modification processes and remained as the initial nanoparticles throughout the 7-day study period.« less

  9. Evolution of silver nanoparticles in the rat lung investigated by X-ray absorption spectroscopy

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

    Davidson, R. Andrew; Anderson, Donald S.; Van Winkle, Laura S.

    Following a 6-h inhalation exposure to aerosolized 20 and 110 nm diameter silver nanoparticles, lung tissues from rats were investigated with X-ray absorption spectroscopy, which can identify the chemical state of silver species. Lung tissues were processed immediately after sacrifice of the animals at 0, 1, 3, and 7 days post exposure and the samples were stored in an inert and low-temperature environment until measured. We found that it is critical to follow a proper processing, storage and measurement protocol; otherwise only silver oxides are detected after inhalation even for the larger nanoparticles. The results of X-ray absorption spectroscopy measurementsmore » taken in air at 85 K suggest that the dominating silver species in all the postexposure lung tissues were metallic silver, not silver oxide, or solvated silver cations. The results further indicate that the silver nanoparticles in the tissues were transformed from the original nanoparticles to other forms of metallic silver nanomaterials and the rate of this transformation depended on the size of the original nanoparticles. Furthermore, we found that 20 nm diameter silver nanoparticles were significantly modified after aerosolization and 6-h inhalation/deposition, whereas larger, 110 nm diameter nanoparticles were largely unchanged. Over the seven-day postexposure period the smaller 20 nm silver nanoparticles underwent less change in the lung tissue than the larger 110 nm silver nanoparticles. In contrast, silica-coated gold nanoparticles did not undergo any modification processes and remained as the initial nanoparticles throughout the 7-day study period.« less

  10. In vitro percutaneous penetration and characterization of silver from silver-containing textiles

    PubMed Central

    Bianco, Carlotta; Kezic, Sanja; Crosera, Matteo; Svetličić, Vesna; Šegota, Suzana; Maina, Giovanni; Romano, Canzio; Larese, Francesca; Adami, Gianpiero

    2015-01-01

    The objective of this study was to determine the in vitro percutaneous penetration of silver and characterize the silver species released from textiles in different layers of full thickness human skin. For this purpose, two different wound dressings and a garment soaked in artificial sweat were placed in the donor compartments of Franz cells for 24 hours. The concentration of silver in the donor phase and in the skin was determined by an electrothermal atomic absorption spectrometer (ET-AAS) and by inductively coupled plasma mass spectrometer (ICP-MS). The characterization of silver species in the textiles and in the skin layers was made by scanning electron microscopy with integrated energy dispersive X-ray spectroscopy (SEM-EDX). Additionally, the size distribution of silver nanoparticles in the textiles was performed by atomic force microscopy (AFM). On the surface of all investigated materials, silver nanoparticles of different size and morphology were found. Released silver concentrations in the soaking solutions (ie, exposure concentration) ranged from 0.7 to 4.7 μg/mL (0.6–4.0 μg/cm2), fitting the bactericidal range. Silver and silver chloride aggregates at sizes of up to 1 μm were identified both in the epidermis and dermis. The large size of these particles suggests that the aggregation occurred in the skin. The formation of these aggregates likely slowed down the systemic absorption of silver. Conversely, these aggregates may form a reservoir enabling prolonged release of silver ions, which might lead to local effects. PMID:25792824

  11. Effect of silver nanoparticles on concentration of silver heavy element and growth indexes in cucumber ( Cucumis sativus L . negeen)

    NASA Astrophysics Data System (ADS)

    Shams, Gholamabbas; Ranjbar, Morteza; Amiri, Aliasghar

    2013-05-01

    The tremendous progress on nanoparticle research area has been made significant effects on the economy, society, and the environment. Silver nanoparticle is one of the most important particles in these categories. Silver nanoparticles can be converted to the heavy silver metal in water by oxidation. Moreover, in the high amounts of silver concentration, they will be accumulated in different parts of the plant. However, by changing the morphology of the plant, the production will be harmful for human consumptions. In this study, nano-powders with average 50 nm silver particles are mixed with deionized distilled water in a completely randomized design. Seven treatments with various concentrations of suspension silver nanoparticles were prepared and repeated in four different parts of the plant in a regular program of spraying. Samples were analyzed to study the growth indexes and concentration of silver in different parts of the plant. It was observed that with increasing concentration of silver nanoparticles on cucumber, the growth indexes (except pH fruit), and the concentration of silver heavy metal are increased significantly. The incremental concentration had the linear relationship with correlation coefficient 0.95 and an average of 0.617 PPM by increasing of each unit in one thousand concentration of nanosilver. Although, by increasing concentration of silver nanoparticles as spraying form, the plant morphological characteristics were improved, the concentration of silver heavy metal in various plant organs was increased. These results open a new pathway to consider the effect of nanoparticles on plant's productions for human consumptions.

  12. Impurities, Defects and Diffusion in Semiconductors: Bulk and Layered Structures. Materials Research Society Symposium Proceedings. Volume 163

    DTIC Science & Technology

    1990-11-21

    VOLUME 16 -mg iis veet n ’ O V-15 19910 -. 4 EDIOR Doad .Wofr I~ ~ ~~ez ’PSRBNSAEMnT E u g ene________________________________________ E .H l e rn...Apraed~f2 pblicrelase REPORT DOCUMENTATION PAGE O A0QrQV & 9e~~~~a~~~.aww~~~Mxi or~ &W.m~ OVW oft f"t9t 9,f9~b~ 4WcN6W WIU i o i 1 19 i 900S S.t 4t0...80111 -0 m i,0 a.1 oe O &. I qu.+ A o lmZ.43r. 4 tO MI tP oc 09 4a0.a wt ൉*4 4K. saw** A’ " AVD0" (O0t7C464.ww:= oc ’as"j. 1. AGENCY USE ONLY (L+w wWn

  13. SESAME-A System of Equations for the Simulation of Aircraft in a Modular Environment.

    DTIC Science & Technology

    1979-01-01

    LCU lAT E 5007 1115 4(t.8C17155 259 CALL SV (LOCI 264/ C C ALCULATE ALPHA * 1 *0 5E7A *510 ASSOCIAT ED E15.L5,C051N18 3* 1 C ALL SAL ’B( TlO 1L!Il 252 15*0...SIIANYI,, 11 .CRIP,IIP. UNITS CALC U LAT (S) U$ID RI. RANG IN IN • • 1 N’ ISTAL sIR ~P5%9 P I.’55 c 1 ~ 115( 1 liNt? IPELICS 45 VII? II?*~ AI R •PIED ..NFYI...79008~J â V L IJ lIJ~~00 0 10 ~) 0 1 ” “ROYAL AIRCRAFT ESTABLISHMENT * c 1 ’~~ech n Ic a I ~~t~~9 0 63i ~~ SAME—A SYSTEM OF EQUATIONSI OF AIRCRAFTL_

  14. Reduction of silver (I) using defatted cashew nut shell starch and its structural comparison with commercial product.

    PubMed

    Velmurugan, Palanivel; Park, Jung-Hee; Lee, Sang-Myeong; Jang, Jum-Suk; Yi, Young-Joo; Han, Sang-Sub; Lee, Sang-Hyun; Cho, Kwang-Min; Cho, Min; Oh, Byung-Taek

    2015-11-20

    In this current study, we report on the reduction of noble metal silver into silver nanoparticles using defatted cashew nut shell (CNS) starch as both the reducing and capping agents. Furthermore, it was compared with commercially available silver nanopowder for the first time. Color changes, ultraviolet-visible spectra (433.76nm), X-ray diffraction peaks (2θ=37.8, 46.3, 66.2, and 77.92) revealed the face-centered cubic (fcc) geometry of silver nanoparticles, scanning electron microscopy-energy dispersive spectroscopy confirmed the presence of elemental silver nanoparticles and the defatted CNS starch silver nanoparticle structures was in accordance to commercial silver nanopowder. The size of both the nanoparticles was found to be similar in the range of 10-50nm as analyzed using high resolution-transmission electron micrographs. The FT-IR spectroscopy revealed the shifting of NH and OH of defatted CNS starch, starch based silver nanoparticle and commercial silver nanopowder has parallel functional groups. The use of environmentally benign and renewable materials like defatted CNS starch offers an alternative to large scale synthesis of silver nanoparticle and includes numerous benefits like eco-friendly and compatibility for pharmaceutical and biomedical applications. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Reduction in Wound Bioburden using a Silver-Loaded Dissolvable Microfilm Construct

    PubMed Central

    Herron, Maggie; Agarwal, Ankit; Kierski, Patricia R.; Calderon, Diego F.; Teixeira, Leandro B. C.; Schurr, Michael J.; Murphy, Christopher J.

    2014-01-01

    Silver is a widely used antimicrobial agent, yet when impregnated in macroscopic dressings, it stains wounds, can lead to tissue toxicity and can inhibit healing. Recently, we reported that polymeric nanofilms containing silver nanoparticles exhibit antimicrobial activity at loadings and release rates of silver that are 100x lower than conventional dressings. Here we report fabrication of composite microfilm constructs that provide a facile way to transfer the silver-loaded polymeric nanofilms onto wounds in vivo. The construct is fabricated from a silver nanoparticle-loaded polymeric nanofilm that is laminated with a micrometer-thick soluble film of polyvinylalcohol (PVA). When placed on a moist wound, the PVA dissolves, leaving the silver-loaded nanofilm immobilized on the wound-bed. In vitro, the immobilized nanofilms release <1 μg cm−2/day of silver over 30 days from skin-dermis and they kill 5 log10 CFUs of Staphylococcus aureus in 24 h. In mice, wounds inoculated with 105 CFU S. aureus presented up to 3 log10 less bacterial burden when treated with silver/nanofilms for 3 days, as compared to unmodified wounds. In uncontaminated wounds, silver/nanofilms allow normal and complete wound closure by re-epithelialization. We conclude that dissolvable microfilm constructs may overcome key limitations associated with current uses of silver in wound healing. PMID:24523027

  16. Electroless growth of silver nanoparticles into mesostructured silica block copolymer films.

    PubMed

    Bois, Laurence; Chassagneux, Fernand; Desroches, Cédric; Battie, Yann; Destouches, Nathalie; Gilon, Nicole; Parola, Stéphane; Stéphan, Olivier

    2010-06-01

    Silver nanoparticles and silver nanowires have been grown inside mesostructured silica films obtained from block copolymers using two successive reduction steps: the first one involves a sodium borohydride reduction or a photoreduction of silver nitrate contained in the film, and the second one consists of a silver deposit on the primary nanoparticles, carried out by silver ion solution reduction with hydroxylamine chloride. We have demonstrated that the F127 block copolymer ((PEO)(106)(PPO)(70)(PEO)(106)), "F type", mesostructured silica film is a suitable "soft" template for the fabrication of spherical silver nanoparticles arrays. Silver spheres grow from 7 to 11 nm upon the second reduction step. As a consequence, a red shift of the surface plasmon resonance associated with metallic silver has been observed and attributed to plasmonic coupling between particles. Using a P123 block copolymer ((PEO)(20)(PPO)(70)(PEO)(20)), "P type", mesostructured silica film, we have obtained silver nanowires with typical dimension of 10 nm x 100 nm. The corresponding surface plasmon resonance is blue-shifted. The hydroxylamine chloride treatment appears to be efficient only when a previous chemical reduction is performed, assuming that the first sodium borohydride reduction induces a high concentration of silver nuclei in the first layer of the porous silica (film/air interface), which explains their reactivity for further growth.

  17. Intravenous Exposure of Pregnant Mice to Silver Nanoparticles: Silver Tissue Distribution and Effects in Maternal and Extra-Embryonic Tissues and Embryos

    NASA Astrophysics Data System (ADS)

    Austin, Carlye Anne

    This research explores the tissue distribution of silver, as well as adverse effects in pregnant mice and embryos, following prenatal silver nanoparticle (AgNP) exposure. Chapter one of this dissertation is a survey of the published literature on the reproductive and/or developmental toxicity of AgNPs. The available data indicate that AgNPs adversely affect sperm count, viability, and/or motility both in vivo and in vitro, and cause apoptosis and necrosis in spermatogonial stem cells and testicular cells. Additionally, AgNP exposure results in mortality and morphological deformities in fish embryos, but produces no adverse effects in chicken embryos. The current published research on in vivo AgNP exposure to mammals during gestation consists of only three studies, one of which is described in chapter two of this dissertation. These studies report results that may suggest a potential for adverse effects on fetal development (e.g. , decreased viability and fetal and placental weights, increased incidence of developmentally young embryos), but additional research is needed. Chapter two of this dissertation investigates the distribution of silver in tissues of pregnant mice and gestation day (GD) 10 embryos following intravenous maternal exposure to 50 nm AgNPs during early organogenesis (GDs 7-9). Examinations of embryo morphology and histology were also performed. Results demonstrated the presence of silver in all organs and tissues examined. Silver concentrations were highest in liver, spleen, and visceral yolk sac, and lowest in embryos. Groups of mice were also treated with soluble silver nitrate, and the pattern of silver tissue distribution following silver nitrate exposure was similar to that which followed AgNP treatment. Transmission electron microscopy-energy dispersive x-ray spectroscopy (TEM-EDS) confirmed the presence of vesicle-bound nanoparticulate silver in visceral yolk sac endoderm, but not mesoderm. This finding, along with the high silver concentration in visceral yolk sac and low silver concentration in embryos, suggests that visceral yolk sac tissue mitigates AgNP transfer to embryos. No significant treatment-related effects on embryo morphology or tissue histology were detected. Chapter three constitutes an expanded study of silver distribution in pregnant mice and developing embryos, with the addition of 10 nm AgNP treatment groups and examination of fetuses at GD16. Very low concentrations of silver were measured in GD10 embryos and GD16 fetuses following 10 nm AgNP treatment or in GD16 fetuses following 50 nm AgNP treatment. Highest silver concentrations were measured in maternal liver, spleen, and visceral yolk sac. AgNP particle size (10 or 50 nm) did not consistently affect silver tissue distribution. At GD10, 50 nm AgNP treatment resulted in significantly higher silver concentrations than 10 nm AgNP treatment for liver, spleen, and visceral yolk sac only; at GD16, in visceral yolk sac only, 10 nm AgNP treatment resulted in a significantly higher silver concentration than 50 nm AgNP treatment. In liver, spleen, visceral yolk sac, and uterus, absolute silver concentrations following 10 nm AgNP treatment were significantly lower at GD16 compared to GD10; the patterns of silver tissue distribution were similar at both time points. Silver nitrate and 10 nm AgNP treatments resulted in similar tissue concentrations in GD10 tissues with the exception of visceral yolk sac, for which the silver concentration was significantly higher after silver nitrate treatment. Silver distribution patterns were generally similar between 10 nm AgNP and silver nitrate treatments. No histological abnormalities were noted in maternal tissues, extra-embryonic tissues, or embryos. A significantly increased incidence of developmentally young (for gestational age) GD10 embryos was seen following 10 nm AgNP treatment; no significant morphological effects were observed in embryos or maternal tissues. Further research will be needed to fully evaluate potential effects of prenatal AgNP exposure on embryos. (Abstract shortened by UMI.)

  18. 31 CFR 56.1 - Conditions upon which silver will be sold.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Conditions upon which silver will be sold. 56.1 Section 56.1 Money and Finance: Treasury Regulations Relating to Money and Finance DOMESTIC GOLD AND SILVER OPERATIONS SALE OF SILVER § 56.1 Conditions upon which silver will be sold. The General...

  19. U.S. EPA, Pesticide Product Label, , 05/21/1982

    EPA Pesticide Factsheets

    2011-04-14

    ... l I ~ 1 I \\ , r.;v 111'01 fJIM'"''' 0 ~~.~ ClN<1'N' rtffdJ /It ~ ... 'f r.(yO {;"?f!IeNI"~iH ... ·It « fl¥l.tlP''t~. liM I "p"IGf fSnAO~~Cor~~"i'"''' J,."""f ... ,'I iI--.:ft.,·j. ...

  20. Thermophysical and Electronic Properties Information Analysis Center (TEPIAC). A Continuing Systematic Program on Data Tables of Thermophysical and Electronic Properties of Materials.

    DTIC Science & Technology

    1981-05-01

    cermets, intermetallics, polymers, tomposites, elements, compounds, glasses , coatings, systems, materials, data 1tion. data evaluation, data analysis...intermetallics, glasses , ceramics, cermets, applied coatings, polymers, composites, and systems. The strategy of literature search has been to use both the...Tv i]3qTMt- I I [ 1 f-TL 1i 1: I 11c IQ I HT. Tsfl-)EN11R2 P- J 99’)~ 0 J917 V2O5 Vanadium Ox ide Li~~~~~~~~j ff T7AV~fi YJ rILLVL7T_(For

  1. Hybrid Fluorosilicones for Aircraft Fuel Tank Sealants. Part 4. Synthesis of Fluorocarbon and Fluorocarbon Ether Hybrid Fluorosilicone Polymers.

    DTIC Science & Technology

    1974-05-01

    onine n oviro id i ncesay (Coidntiu d onac evesesie fluoroether SECURITY CLASIICAIO OFstuei THISer wAGE sythsie,and uRred) research~~~~~~~~ amle wer...i I. ." r;. . - 7 7 7 SECTION Table of Contents (Continued)Page b. Preparation of CHa-CH(CFa)aO(CFa),O( CFt )CH-CH* ............ 27 c. Preparation of...Photolysis of I(CFg)aO(CPs)nO(CFm)aI/Hg/ CFt .................. 32 6. Reaction of I(CFR)&O(CF,).O(CFa)s1 with Hg ..................... 33 a. 280 0C

  2. Loves Park Creek, Loves Park, Illinois Local Flood Protection. General Design Memorandum with Environmental Assessment. Revision

    DTIC Science & Technology

    1990-06-01

    accelssCo, ~~e 61:6 ififectrica/ ca ndul’ -Aaq Accas hatch tSelf _____,?q ’EL /4s0 ~~~~~~~c ~ ~ ~ ~ s c) Q a~ri ty 5 iate I i q’ ,mfi AI r IIAcce ss shai...Goverment Audit F-il Article XIII - Federal and State Laws F-il Article XIV - Relationship of Parties F-il Article XV - Officials not to Benefit F-l1...shall not exceed the actual audited , allowable costs of Pebble Creek Dam that are allocable to the Project, nor shall the credits exceed the value of the

  3. Dollar Summary of Federal Supply Classification and Service Category by Company. Part 2 (B502-J066)

    DTIC Science & Technology

    1990-01-01

    U 0 V ) V ( w~~~~ ae a11 - 4 W 4 0~~~~ a a4 " A 0 1> z~~~~ a. a0 4 0 4 1 4 ,0 4 - 4a%- %. 0 4a4 t4 i acca Lu awHIu 0a 0 0 0 Iw awa In InI I IK t0 n 4...f0 <z 1. 0 m) 1-4 w 0 .0 0 ) 0 w ’ -J z U) 1-- -- &a x -- m < I z w z 0 F- or. o LU c-c, J O "I- "I- 11-1 0 F1 {A - " " :)ix [ I-- . U H E (. 0 ’ C3...I Ir 10 0 10 - U I I CO F1 4 04 U 40 40 IWI O 4 -~ ~ ~ OF- ~ 1 Z E c’) a Sc 0 00 -4 𔃺 0 U) SO (a e UL N 4 q 0 -4 1 -tr N (0 0) r, (a L0 m w) m 0 -t

  4. Utilization of hydroxypropyl carboxymethyl cellulose in synthesis of silver nanoparticles.

    PubMed

    Abdel-Halim, E S; Alanazi, Humaid H; Al-Deyab, Salem S

    2015-04-01

    Hydroxypropyl carboxymethyl cellulose samples having varying degrees of substitution and varying degrees of polymerization were used to reduce silver nitrate to silver nanoparticles. UV spectral analysis of silver nanoparticles colloidal solution reveal that increasing the pH of the reduction solution leads to improvement in the intensity of the absorption band for silver nanoparticles, to be maximum at pH 11. The absorption peak intensity also enhanced upon prolonging the reaction duration up to 60 min. The conversion of silver ions to metallic silver nanoparticles was found to be temperature-dependent and maximum transformation occurs at 60 °C. The reduction efficiency of hydroxypropyl carboxymethyl cellulose was found to be affected by its degree of polymerization. Colloidal solutions of silver nanoparticles having concentration up to 1000 ppm can be prepared upon fixing the ratio between silver nitrate and hydroxypropyl carboxymethyl cellulose at 0.017-0.3g per each 100ml of the reduction solution. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Facile synthesis and characterization of silver nanoparticle/bis(o-phenolpropyl)silicone composites using a gold catalyst.

    PubMed

    Roh, Sung-Hee; Cheong, Hyeonsook; Kim, Do-Heyoung; Woo, Hee-Gweon; Lee, Byeong-Gweon; Yang, Kap-Seung; Kim, Bo-Hye; Sohn, Honglae

    2013-01-01

    The generation of silver nanoparticle/bis(o-phenolpropyl)silicone composites have been facilitated by the addition of sodium tetrachloroaurate or gold(Ill) chloride (< 1 wt% of NaAuCl4 or AuCl3) to the reaction of silver nitrate (AgNO3) with bis(o-phenolpropyl)silicone [BPPS, (o-phenolpropyl)2(SiMe2O)n, n = 2,3,8,236]. TEM and FE-SEM data showed that the silver nanoparticles having the size of < 20 nm are well dispersed throughout the BPPS silicone matrix in the composites. XRD patterns are consistent with those for polycrystalline silver. The size of silver nanoparticles augmented with increasing the relative molar concentration of AgNO3 added with respect to BPPS. The addition of gold complexes (1-3 wt%) did not affect the size distribution of silver nanoparticles appreciably. In the absence of BPPS, the macroscopic precipitation of silver by agglomeration, indicating that BPPS is necessary to stabilize the silver nanoparticles surrounded by coordination.

  6. Electrochemical Study and Applications of Selective Electrodeposition of Silver on Quantum Dots.

    PubMed

    Martín-Yerga, Daniel; Rama, Estefanía Costa; Costa-García, Agustín

    2016-04-05

    In this work, selective electrodeposition of silver on quantum dots is described. The particular characteristics of the nanostructured silver thus obtained are studied by electrochemical and microscopic techniques. On one hand, quantum dots were found to catalyze the silver electrodeposition, and on the other hand, a strong adsorption between electrodeposited silver and quantum dots was observed, indicated by two silver stripping processes. Nucleation of silver nanoparticles followed different mechanisms depending on the surface (carbon or quantum dots). Voltammetric and confocal microscopy studies showed the great influence of electrodeposition time on surface coating, and high-resolution transmission electron microscopy (HRTEM) imaging confirmed the initial formation of Janus-like Ag@QD nanoparticles in this process. By use of moderate electrodeposition conditions such as 50 μM silver, -0.1 V, and 60 s, the silver was deposited only on quantum dots, allowing the generation of localized nanostructured electrode surfaces. This methodology can also be employed for sensing applications, showing a promising ultrasensitive electrochemical method for quantum dot detection.

  7. Evaluation of dose dependent antimicrobial activity of self-assembled chitosan, nano silver and chitosan-nano silver composite against several pathogens.

    PubMed

    Tareq, Foysal Kabir; Fayzunnesa, Mst; Kabir, Md Shahariar; Nuzat, Musrat

    2018-01-01

    The aim of this investigation to preparation of silver nanoparticles organized chitosan nano polymer, which effective against microbial and pathogens, when apply to liquid medium and edible food products surface, will rescue the growth of microbes. Self-assembly approach used to synthesis of silver nanoparticles and silver nanoparticles organized chitosan nano polymer. Silver nanoparticles and silver nanoparticles organized chitosan nano polymer and film characterized using Ultra-violate visible spectrometer (UV-vis), X-ray diffraction (X-ray), and Scanning electronic microscope (SEM). The crystalline structured protein capped nano silver successfully synthesized at range of 12 nm-29 nm and organized into chitosan nano polymer. Antimicrobial ingredient in liquid medium and food product surface provide to rescue oxidative change and growth of microorganism to provide higher safety. The silver nanoparticles organized chitosan nano polymer caused the death of microorganism. The materials in nano scale synthesized successfully using self-assembly method, which showed good antimicrobial properties. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. An environmentally benign antimicrobial nanoparticle based on a silver-infused lignin core.

    PubMed

    Richter, Alexander P; Brown, Joseph S; Bharti, Bhuvnesh; Wang, Amy; Gangwal, Sumit; Houck, Keith; Cohen Hubal, Elaine A; Paunov, Vesselin N; Stoyanov, Simeon D; Velev, Orlin D

    2015-09-01

    Silver nanoparticles have antibacterial properties, but their use has been a cause for concern because they persist in the environment. Here, we show that lignin nanoparticles infused with silver ions and coated with a cationic polyelectrolyte layer form a biodegradable and green alternative to silver nanoparticles. The polyelectrolyte layer promotes the adhesion of the particles to bacterial cell membranes and, together with silver ions, can kill a broad spectrum of bacteria, including Escherichia coli, Pseudomonas aeruginosa and quaternary-amine-resistant Ralstonia sp. Ion depletion studies have shown that the bioactivity of these nanoparticles is time-limited because of the desorption of silver ions. High-throughput bioactivity screening did not reveal increased toxicity of the particles when compared to an equivalent mass of metallic silver nanoparticles or silver nitrate solution. Our results demonstrate that the application of green chemistry principles may allow the synthesis of nanoparticles with biodegradable cores that have higher antimicrobial activity and smaller environmental impact than metallic silver nanoparticles.

  9. Physicochemical fabrication of antibacterial calcium phosphate submicrospheres with dispersed silver nanoparticles via coprecipitation and photoreduction under laser irradiation.

    PubMed

    Nakamura, Maki; Oyane, Ayako; Shimizu, Yoshiki; Miyata, Saori; Saeki, Ayumi; Miyaji, Hirofumi

    2016-12-01

    We achieved rapid, surfactant-free, and one-pot fabrication of antibacterial calcium phosphate (CaP) submicrospheres containing silver nanoparticles by combining physical laser and chemical coprecipitation processes. In this physicochemical process, weak pulsed laser irradiation (20min) was performed on a labile CaP reaction mixture supplemented with silver ions as a light-absorbing agent. The silver content in the submicrospheres was controlled for a wide range (Ag/P elemental ratio varied from 0.60 to 62.0) by tuning the initial concentration of silver ions (from 5 to 20mM) in the CaP reaction mixture. At the silver concentration of 5mM, we obtained unique nanocomposite particles: CaP submicrospheres (average diameter of approximately 500nm) containing metallic silver nanoparticles dispersed throughout, as a result of CaP and silver coprecipitation with simultaneous photoreduction of silver ions and spheroidization of the coprecipitates. These CaP submicrospheres containing silver nanoparticles (ca. 0.3mg silver per 1mg submicrospheres) exhibited antibacterial activity against major pathogenic oral bacteria, i.e., Streptococcus mutans, Aggregatibacter actinomycetemcomitans, and Porphyromonas gingivalis. Moreover, the CaP submicrospheres dissolved and neutralized the acidic environment generated by Streptococcus mutans, demonstrating their potential as acid-neutralizing and remineralizing agents. The present process and resulting antibacterial CaP-based submicrospheres are expected to be useful in dental healthcare and infection control. Nano- and microsized spheres of calcium phosphate (CaP) containing silver nanoparticles have great potential in dental applications. Conventional fabrication processes were time-consuming or weak regarding the size/shape control of the spheres. In this study, we achieved a simple (one-pot), rapid (20-min irradiation), and surfactant-free fabrication of CaP submicrospheres containing silver nanoparticles by pulsed laser irradiation to a mixture of calcium, phosphate, and silver ion solutions. The resulting CaP submicrospheres contained metallic silver nanoparticles dispersed throughout in a sequence of reactions: CaP and silver coprecipitation, laser-induced melting and spheroidization of the coprecipitates, and photoreduction of silver ions. These submicrospheres showed antibacterial activity against oral bacteria and acid-neutralizing property in the bacterial suspension, and hence are worth considering for dental applications. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  10. Nucleic acid nanomaterials: Silver-wired DNA

    NASA Astrophysics Data System (ADS)

    Auffinger, Pascal; Ennifar, Eric

    2017-10-01

    DNA double helical structures are supramolecular assemblies that are typically held together by classical Watson-Crick pairing. Now, nucleotide chelation of silver ions supports an extended silver-DNA hybrid duplex featuring an uninterrupted silver array.

  11. Genetics Home Reference: Russell-Silver syndrome

    MedlinePlus

    ... Facebook Twitter Home Health Conditions Russell-Silver syndrome Russell-Silver syndrome Printable PDF Open All Close All ... Javascript to view the expand/collapse boxes. Description Russell-Silver syndrome is a growth disorder characterized by ...

  12. Formation Regularities of Plasmonic Silver Nanostructures on Porous Silicon for Effective Surface-Enhanced Raman Scattering

    NASA Astrophysics Data System (ADS)

    Bandarenka, Hanna V.; Girel, Kseniya V.; Bondarenko, Vitaly P.; Khodasevich, Inna A.; Panarin, Andrei Yu.; Terekhov, Sergei N.

    2016-05-01

    Plasmonic nanostructures demonstrating an activity in the surface-enhanced Raman scattering (SERS) spectroscopy have been fabricated by an immersion deposition of silver nanoparticles from silver salt solution on mesoporous silicon (meso-PS). The SERS signal intensity has been found to follow the periodical repacking of the silver nanoparticles, which grow according to the Volmer-Weber mechanism. The ratio of silver salt concentration and immersion time substantially manages the SERS intensity. It has been established that optimal conditions of nanostructured silver layers formation for a maximal Raman enhancement can be chosen taking into account a special parameter called effective time: a product of the silver salt concentration on the immersion deposition time. The detection limit for porphyrin molecules CuTMPyP4 adsorbed on the silvered PS has been evaluated as 10-11 M.

  13. A new chemical route to a hybrid nanostructure: room-temperature solid-state reaction synthesis of Ag@AgCl with efficient photocatalysis.

    PubMed

    Hu, Pengfei; Cao, Yali

    2012-08-07

    The room-temperature solid-state chemical reaction technique has been used to synthesize the silver nanoparticle-loaded semiconductor silver@silver chloride for the first time. It has the advantages of convenient operation, lower cost, less pollution, and mass production. This simple technique created a wide array of nanosized silver particles which had a strong surface plasmon resonance effect in the visible region, and built up an excellent composite structure of silver@silver chloride hybrid which exhibited high photocatalytic activity and stability towards decomposition of organic methyl orange under visible-light illumination. Moreover, this work achieved the control of composition of the silver@silver chloride composite simply by adjusting the feed ratio of reactants. It offers an alternative method for synthesising metal@semiconductor composites.

  14. Formation of hybrid nanocomposites polymethylolacrylamide/silver

    NASA Astrophysics Data System (ADS)

    Kolzunova, L. G.; Shchitovskaya, E. V.; Rodzik, I. G.

    2018-05-01

    In this study, polymethylolacrylamide/silver composites have been formed by incorporating silver nanoparticles into the pre-electrosynthesized polymer film. The composites were formed in a two-step process involving the sorption of silver nitrate by a polymer matrix followed by chemical reduction of Ag-ions. The presence of crystalline silver phase in the polymer was confirmed by X-ray phase analysis (XRD), plasmon resonance and scanning electron microscopy (SEM). The small-angle X-ray scattering (SAXS) method has obtained the distribution functions of silver particles over radii. It is established that the content of silver in composites without chitosan is 10-15 times higher than with its additive. The dependences of cyclic voltammetry in pure phosphate buffer (pH 6.86) and in the presence of hydrogen peroxide were obtained. It has been shown that polymer/silver composites exhibit selectivity to hydrogen peroxide.

  15. Silver, gold, and alloyed silver-gold nanoparticles: characterization and comparative cell-biologic action

    NASA Astrophysics Data System (ADS)

    Mahl, Dirk; Diendorf, Jörg; Ristig, Simon; Greulich, Christina; Li, Zi-An; Farle, Michael; Köller, Manfred; Epple, Matthias

    2012-10-01

    Silver, gold, and silver-gold-alloy nanoparticles were prepared by citrate reduction modified by the addition of tannin during the synthesis, leading to a reduction in particle size by a factor of three. Nanoparticles can be prepared by this easy water-based synthesis and subsequently functionalized by the addition of either tris(3-sulfonatophenyl)phosphine or poly( N-vinylpyrrolidone). The resulting nanoparticles of silver (diameter 15-25 nm), gold (5-6 nm), and silver-gold (50:50; 10-12 nm) were easily dispersable in water and also in cell culture media (RPMI + 10 % fetal calf serum), as shown by nanoparticle tracking analysis and differential centrifugal sedimentation. High-resolution transmission electron microscopy showed a polycrystalline nature of all nanoparticles. EDX on single silver-gold nanoparticles indicated that the concentration of gold is higher inside a nanoparticle. The biologic action of the nanoparticles toward human mesenchymal stem cells (hMSC) was different: Silver nanoparticles showed a significant concentration-dependent influence on the viability of hMSC. Gold nanoparticles showed only a small effect on the viability of hMSC after 7 days. Surprisingly, silver-gold nanoparticles had no significant influence on the viability of hMSC despite the silver content. Silver nanoparticles and silver-gold nanoparticles in the concentration range of 5-20 μg mL-1 induced the activation of hMSC as indicated by the release of IL-8. In contrast, gold nanoparticles led to a reduction of the release of IL-6 and IL-8.

  16. Occurrence of silver minerals in a silver-rich pocket in the massive sulfide zinc-lead ores in the Edwards mine, New York

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

    Serviss, C.R.; Grout, C.M.; Hagni, R.D.

    1985-01-01

    Ore microscopic examination of uncommon silver-rich ores from the Edwards mine has detected three silver minerals, native silver, freibergite, and argentite, that were previously unreported in the literature from the Balmat-Edwards district. The zinc-lead ore deposits of the Balmat-Edwards District in northern New York are composed of very coarse-grained massive sulfides, principally sphalerite, galena, and pyrite. The typical ores contain small amounts of silver in solid solution galena. Galena concentrates produced from those ores have contained an average of 15 ounces of silver per ton of 60% lead concentrates. In contrast to the typical ore a silver-rich pocket, that measuredmore » three feet by three feet on the vertical mine face and was the subject of this study, contained nearly 1% silver in a zinc ore. Ore microscopic study shows that this ore is especially characterized by abundant, relatively fine-grained chalcopyrite with anhedral pyrite inclusions. Fine-grained sphalerite, native silver, argentite, freibergite and arsenopyrite occur in association with the chalcopyrite and as fracture-fillings in gangue minerals. Geochemically anomalous amounts of tin, barium, chromium, and nickel also are present in the silver-rich pocket. The silver-rich pocket may mark the locus of an early feeder vent or alternatively it may record a hydrothermal event that was superimposed upon the event responsible for the metamorphic ore textures.« less

  17. Specific composition of native silver from the Rogovik Au-Ag deposit, Northeastern Russia

    NASA Astrophysics Data System (ADS)

    Kravtsova, R. G.; Tauson, V. L.; Palyanova, G. A.; Makshakov, A. S.; Pavlova, L. A.

    2017-09-01

    The first data on native silver from the Rogovik Au-Ag deposit in northeastern Russia are presented. The deposit is situated in central part of the Okhotsk-Chukchi Volcanic Belt (OCVB) in the territory of the Omsukchan Trough, unique in its silver resources. Native silver in the studied ore makes up finely dispersed inclusions no larger than 50 μm in size, which are hosted in quartz; fills microfractures and interstices in association with küstelite, electrum, acanthite, silver sulfosalts and selenides, argyrodite, and pyrite. It has been shown that the chemical composition of native silver, along with its typomorphic features, is a stable indication of the various stages of deposit formation and types of mineralization: gold-silver (Au-Ag), silver-base metal (Ag-Pb), and gold-silver-base metal (Au-Ag-Pb). The specificity of native silver is expressed in the amount of trace elements and their concentrations. In Au-Ag ore, the following trace elements have been established in native silver (wt %): up to 2.72 S, up to 1.86 Au, up to 1.70 Hg, up to 1.75 Sb, and up to 1.01 Se. Native silver in Ag-Pb ore is characterized by the absence of Au, high Hg concentrations (up to 12.62 wt %), and an increase in Sb, Se, and S contents; the appearance of Te, Cu, Zn, and Fe is notable. All previously established trace elements—Hg, Au, Sb, Se, Te, Cu, Zn, Fe, and S—are contained in native silver of Au-Ag-Pb ore. In addition, Pb appears, and silver and gold amalgams are widespread, as well as up to 24.61 wt % Hg and 11.02 wt % Au. Comparison of trace element concentrations in native silver at the Rogovik deposit with the literature data, based on their solubility in solid silver, shows that the content of chalcogenides (S, Se, Te) exceeds saturated concentrations. Possible mechanisms by which elevated concentrations of these elements are achieved in native silver are discussed. It is suggested that the appearance of silver amalgams, which is unusual for Au-Ag mineralization not only in the Omsukchan Trough, but also in OCVB as a whole, is caused by superposition of the younger Dogda-Erikit Hg-bearing belt on the older Ag-bearing Omsukchan Trough. In practice, the results can be used to determine the general line of prospecting and geological exploration at objects of this type.

  18. U.S. EPA, Pesticide Product Label, COOKE SEVIN BRAND LIQUID CARBARYL INSECTICIDE, 07/10/1989

    EPA Pesticide Factsheets

    2011-04-14

    ... '('l~ i~'fdlU:tlOf: te. StJrfi(f~ ~~frf ~'~~~f spril~ rt£)d~fS ~~f CbJf(tIClni~!f. ~t hot kSf t~l! ~rodo(t JTI e,' en f:fctrHel f'Ql!J~Hf!t dCt: tv tt.E- pU:'~I~ilit,. ...

  19. Ultra Lightweight Mirror Fabrication Technology

    DTIC Science & Technology

    1983-12-01

    supported on-back at three points, 120 degrees apart at the 0.7 radial zone. The surface deformation, produced by a one-g gravity load applied to a...reliable and repeatable simulation of zero- gravity . 16 * ....- • • ~~~~~~. ,. ........ ...... ....... o....... .. -.. . ...... " . - tively... gravity loading. The stability of this mirru, over these environmental conditions is considered to be excellent. The interferometrically measured surface

  20. The Effects of Oral Pyridostigmine on Serum Cholinesterase Activity in Macaca mulatta

    DTIC Science & Technology

    1987-01-01

    v! 1tbity Codes ".~~~~~~A 4.,:’.O:t 3;ca -- 1 R 09-4" S Drug Administration and Blood Sampling We developed a mixture of commercially available cookie ... dough and coarsely ground monkey chow as a vehicle for oral administration.. Balls (15-20 ml) of this vehicle were given to potential subjects for

  1. U.S. EPA, Pesticide Product Label, ANSAR 170-H.C. HERBICIDE HIGH CONCENTRATE MSMA LIQUID FOR SELECTIVE PO, 09/11/1972

    EPA Pesticide Factsheets

    2011-04-14

    ... C'fJ · ... ·i~ ·l~~ (j;'1 SL A.:.Jq~;:;llf~C 0 1 .' .,t'f,vde. :':" 3· .... f·~ 1 tI; j': ,." r~~;1 L;(·t:::,. tl··'f~ir,;~r~~. r'.;;I .... 1 f~u'cI {IIJ·~i.:!.: __ .):,: ...

  2. 17 CFR 31.3 - Fraud in connection with certain transactions in silver or gold bullion or bulk coins, or other...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... certain transactions in silver or gold bullion or bulk coins, or other commodities. 31.3 Section 31.3... in connection with certain transactions in silver or gold bullion or bulk coins, or other commodities... transaction for the purchase, sale or delivery of silver bullion, gold bullion, bulk silver coins, bulk gold...

  3. 17 CFR 31.3 - Fraud in connection with certain transactions in silver or gold bullion or bulk coins, or other...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... certain transactions in silver or gold bullion or bulk coins, or other commodities. 31.3 Section 31.3... in connection with certain transactions in silver or gold bullion or bulk coins, or other commodities... transaction for the purchase, sale or delivery of silver bullion, gold bullion, bulk silver coins, bulk gold...

  4. 17 CFR 31.3 - Fraud in connection with certain transactions in silver or gold bullion or bulk coins, or other...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... certain transactions in silver or gold bullion or bulk coins, or other commodities. 31.3 Section 31.3... in connection with certain transactions in silver or gold bullion or bulk coins, or other commodities... transaction for the purchase, sale or delivery of silver bullion, gold bullion, bulk silver coins, bulk gold...

  5. 17 CFR 31.3 - Fraud in connection with certain transactions in silver or gold bullion or bulk coins, or other...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... certain transactions in silver or gold bullion or bulk coins, or other commodities. 31.3 Section 31.3... in connection with certain transactions in silver or gold bullion or bulk coins, or other commodities... transaction for the purchase, sale or delivery of silver bullion, gold bullion, bulk silver coins, bulk gold...

  6. 36 CFR § 1238.30 - What must agencies do when transferring permanent microform records to the National Archives of...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... information specified in § 1232.14(c) of this subchapter. (c) Transfer the silver gelatin original (or duplicate silver gelatin microform created in accordance with § 1238.14) plus one microform copy. (d) Ensure... non-silver copies separately from the silver gelatin original or silver duplicate microform copy and...

  7. Development and Optimization of Silver Nanoparticle Formulation for Fabrication

    DTIC Science & Technology

    2015-08-14

    Development and Optimization of Silver Nanoparticle Formulation for Fabrication Publication Type: DJournal/ Paper D Book Chapter ~ Tech Report D...leofPublicationorPresentation: Deve l opment and Optimization of Silver Nanoparticle Formulation for Fabrication 3. Author(s): (List authors starting...fabrication process of silver nanoparticl es could improve future silver containing products , which is i mpor tant to l owering toxicity and improving

  8. Piper nigrum leaf and stem assisted green synthesis of silver nanoparticles and evaluation of its antibacterial activity against agricultural plant pathogens.

    PubMed

    Paulkumar, Kanniah; Gnanajobitha, Gnanadhas; Vanaja, Mahendran; Rajeshkumar, Shanmugam; Malarkodi, Chelladurai; Pandian, Kannaiyan; Annadurai, Gurusamy

    2014-01-01

    Utilization of biological materials in synthesis of nanoparticles is one of the hottest topics in modern nanoscience and nanotechnology. In the present investigation, the silver nanoparticles were synthesized by using the leaf and stem extract of Piper nigrum. The synthesized nanoparticle was characterized by UV-vis spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive X-ray analysis (EDAX), and Fourier Transform Infrared Spectroscopy (FTIR). The observation of the peak at 460 nm in the UV-vis spectra for leaf- and stem-synthesized silver nanoparticles reveals the reduction of silver metal ions into silver nanoparticles. Further, XRD analysis has been carried out to confirm the crystalline nature of the synthesized silver nanoparticles. The TEM images show that the leaf- and stem-synthesized silver nanoparticles were within the size of about 7-50 nm and 9-30 nm, respectively. The FTIR analysis was performed to identify the possible functional groups involved in the synthesis of silver nanoparticles. Further, the antibacterial activity of the green-synthesized silver nanoparticles was examined against agricultural plant pathogens. The antibacterial property of silver nanoparticles is a beneficial application in the field of agricultural nanotechnology.

  9. The effect and safety of dressing composed by nylon threads covered with metallic silver in wound treatment.

    PubMed

    Brogliato, Ariane R; Borges, Paula A; Barros, Janaina F; Lanzetti, Manuela; Valença, Samuel; Oliveira, Nesser C; Izário-Filho, Hélcio J; Benjamim, Claudia F

    2014-04-01

    Silver is used worldwide in dressings for wound management. Silver has demonstrated great efficacy against a broad range of microorganisms, but there is very little data about the systemic absorption and toxicity of silver in vivo. In this study, the antimicrobial effect of the silver-coated dressing (SilverCoat(®)) was evaluated in vitro against the most common microorganisms found in wounds, including Pseudomonas aeruginosa, Candida albicans, Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus and Klebsiella pneumoniae. We also performed an excisional skin lesion assay in mice to evaluate wound healing after 14 days of treatment with a silver-coated dressing, and we measured the amount of silver in the blood, the kidneys and the liver after treatment. Our data demonstrated that the nylon threads coated with metallic silver have a satisfactory antimicrobial effect in vitro, and the prolonged use of these threads did not lead to systemic silver absorption, did not induce toxicity in the kidneys and the liver and were not detrimental to the normal wound-healing process. © 2012 The Authors. International Wound Journal © 2012 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  10. Powerful colloidal silver nanoparticles for the prevention of gastrointestinal bacterial infections

    NASA Astrophysics Data System (ADS)

    Le, Anh-Tuan; Tam Le, Thi; Quy Nguyen, Van; Hoang Tran, Huy; Dang, Duc Anh; Tran, Quang Huy; Vu, Dinh Lam

    2012-12-01

    In this work we have demonstrated a powerful disinfectant ability of colloidal silver nanoparticles (NPs) for the prevention of gastrointestinal bacterial infections. The silver NPs colloid was synthesized by a UV-enhanced chemical precipitation. Two gastrointestinal bacterial strains of Escherichia coli (ATCC 43888-O157:k-:H7) and Vibrio cholerae (O1) were used to verify the antibacterial activity of the as-prepared silver NPs colloid by means of surface disinfection assay in agar plates and turbidity assay in liquid media. Transmission electron microscopy was also employed to analyze the ultrastructural changes of bacterial cells caused by silver NPs. Noticeably, our silver NPs colloid displayed a highly effective bactericidal effect against two tested gastrointestinal bacterial strains at a silver concentration as low as ˜3 mg l-1. More importantly, the silver NPs colloid showed an enhancement of antibacterial activity and long-lasting disinfectant effect as compared to conventional chloramin B (5%) disinfection agent. These advantages of the as-prepared colloidal silver NPs make them very promising for environmental treatments contaminated with gastrointestinal bacteria and other infectious pathogens. Moreover, the powerful disinfectant activity of silver-containing materials can also help in controlling and preventing further outbreak of diseases.

  11. Occupational exposure limit for silver nanoparticles: considerations on the derivation of a general health-based value.

    PubMed

    Weldon, Brittany A; M Faustman, Elaine; Oberdörster, Günter; Workman, Tomomi; Griffith, William C; Kneuer, Carsten; Yu, Il Je

    2016-09-01

    With the increased production and widespread commercial use of silver nanoparticles (AgNPs), human and environmental exposures to silver nanoparticles are inevitably increasing. In particular, persons manufacturing and handling silver nanoparticles and silver nanoparticle containing products are at risk of exposure, potentially resulting in health hazards. While silver dusts, consisting of micro-sized particles and soluble compounds have established occupational exposure limits (OELs), silver nanoparticles exhibit different physicochemical properties from bulk materials. Therefore, we assessed silver nanoparticle exposure and related health hazards in order to determine whether an additional OEL may be needed. Dosimetric evaluations in our study identified the liver as the most sensitive target organ following inhalation exposure, and as such serves as the critical target organ for setting an occupational exposure standard for airborne silver nanoparticles. This study proposes an OEL of 0.19 μg/m(3) for silver nanoparticles derived from benchmark concentrations (BMCs) from subchronic rat inhalation toxicity assessments and the human equivalent concentration (HEC) with kinetic considerations and additional uncertainty factors. It is anticipated that this level will protect workers from potential health hazards, including lung, liver, and skin damage.

  12. Assessment of Silver Based Disinfection Technology for CEV and Future US Spacecraft

    NASA Technical Reports Server (NTRS)

    Callahan, Michael R.; Adam, Niklas M.; Roberts, Michael S.; Garland, Jay L.; Sager, John C.; Pickering, Karen D.

    2007-01-01

    Silver biocide offers a potential advantage over iodine, the current state-of-the-art in US spacecraft disinfection technology, in that silver can be safely consumed by the crew. As such, silver may reduce the overall complexity and mass of future spacecraft potable water systems, particularly those used to support long duration missions. A primary technology gap identified for the use of silver biocide is one of material compatibility. Wetted materials of construction are required to be selected such that silver ion concentrations can be maintained at biocidally effective levels. Preliminary data on silver biocide depletion rates in heritage spacecraft potable water system wetted-materials of construction has been gathered as part of a multi-phase test project aimed at the characterization of silver based biocide technology through: development of preferred materials lists, investigation of silver biocide forms and delivery methods, down-selection of silver biocide technologies, and integrated testing. A 10% - 20% loss in silver ion concentration per day was observed for acid passivated Nitronic 40 tubing with surface area to volume (S/V) ratios of approximately 4.59 cm-1. The Nitronic 40 tubes were tested both with and without biocide pretreatment. Silver biocide depletion was also observed at approximately 0.1% per day for the first 35 days of exposure to acid passivated Inconel 718 coupon, S/V of approximately 0.14 cm-1. Surface analysis by scanning election microscopy (SEM) suggested deposition of silver metal on both test materials. SEM analysis also provided evidence of potential variability in the passivation process for tube configuration of the Nitronic 40 test apparatus. These preliminary results are presented and discussed herein, along with the current project status.

  13. Residence of silver in mineral deposits of the Thunder Mountain caldera complex, Central Idaho, U.S.A.

    USGS Publications Warehouse

    Leonard, B.F.; Christian, R.P.

    1987-01-01

    Silver is an accessory element in gold, antimony, and tungsten deposits of the caldera complex. Most of the deposits are economically of low grade and genetically of xenothermal or epithermal character. Their gold- and silver-bearing minerals are usually disseminated, fine grained, and difficult to study. Sparsely disseminated pyrite and arsenoprite are common associates. Identified silver minerals are: native silver and electrum; the sulfides acanthite, argentite (the latter always inverted to acanthite), and members of the Silberkies group; the sulfosalts matildite, miargyrite, pyrargyrite, argentian tetrahedrite, and unnamed Ag-Sb-S and Ag-Fe-Sb-S minerals; the telluride hessite and the selenide naumannite; halides of the cerargyrite group; and the antimonate stetefeldtite. Suspected silver minerals include the sulfide uytenbogaardtite and the sulfosalts andorite, diaphorite, and polybasite. Electrum, acanthite, and argentian tetrahedrite are common, though nowhere abundant. The other silver minerals are rare. Silver is present as a minor element in the structure of some varieties of other minerals. These include arsenopyrite, chalcopyrite, chalcostibite, covelline, digenite, galena, sphalerite, and stibnite. The search for adventitious Ag in most of these minerals has been cursory. The results merely indicate that elemental silver is not confined to discrete silver minerals and is, therefore, an additional complication for the recovery of silver-bearing material from some deposits. Silver occurs cryptically in some plants of the region. At Red Mountain, for example, the ashed sapwood of Douglas-fir (Pseudotsuga menziesii) contains 2 to 300 ppm Ag. Silver in the ashed wood is roughly 100 times as abundant as it is in soil. The phenomenon, useful in biogeochemical exploration, deserves the attention of mineralogists. ?? 1987 Springer-Verlag.

  14. In Vitro Assessment of the Antibacterial Potential of Silver Nano-Coatings on Cotton Gauzes for Prevention of Wound Infections

    PubMed Central

    Paladini, Federica; Di Franco, Cinzia; Panico, Angelica; Scamarcio, Gaetano; Sannino, Alessandro; Pollini, Mauro

    2016-01-01

    Multidrug-resistant organisms are increasingly implicated in acute and chronic wound infections, thus compromising the chance of therapeutic options. The resistance to conventional antibiotics demonstrated by some bacterial strains has encouraged new approaches for the prevention of infections in wounds and burns, among them the use of silver compounds and nanocrystalline silver. Recently, silver wound dressings have become widely accepted in wound healing centers and are commercially available. In this work, novel antibacterial wound dressings have been developed through a silver deposition technology based on the photochemical synthesis of silver nanoparticles. The devices obtained are completely natural and the silver coatings are characterized by an excellent adhesion without the use of any binder. The silver-treated cotton gauzes were characterized through scanning electron microscopy (SEM) and thermo-gravimetric analysis (TGA) in order to verify the distribution and the dimension of the silver particles on the cotton fibers. The effectiveness of the silver-treated gauzes in reducing the bacterial growth and biofilm proliferation has been demonstrated through agar diffusion tests, bacterial enumeration test, biofilm quantification tests, fluorescence and SEM microscopy. Moreover, potential cytotoxicity of the silver coating was evaluated through 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide colorimetric assay (MTT) and the extract method on fibroblasts and keratinocytes. Inductively coupled plasma mass spectrometry (ICP-MS) was performed in order to determine the silver release in different media and to relate the results to the biological characterization. All the results obtained were compared with plain gauzes as a negative control, as well as gauzes treated with a higher silver percentage as a positive control. PMID:28773531

  15. Mineral resource of the month: silver

    USGS Publications Warehouse

    Brooks, William E.

    2007-01-01

    Silver has been used for thousands of years as ornaments and utensils, for trade and as the basis of many monetary systems. The metal has played an important part in world history. Silver from the mines at Laurion, Greece, for example, financed the Greek victory over the Persians in 480 B.C. Silver from Potosi, Bolivia, helped Spain become a world power in the 16th and 17th centuries. And silver from the gold-silver ores at the Comstock Lode in Virginia City, Nev., helped keep the Union solvent during the Civil War.

  16. Automated Program Recognition.

    DTIC Science & Technology

    1987-02-01

    the 45 %V. UC I it F I F Figaze~~~~~~~~ 2.3 hIln o h rga G n h lciF .446 1 68%ir eI TI Ti T2 T2 T3 T3 D C B A D C B A ’Ir ioin join join oi join join... Ei (remove-st-thru-input-mappings p ’(Trunc? 1)) finally (return (and (p> (Trunc? 2)) (p> (Trunc7 1))))) (exit-predicate (nt-n) Test-Predicate?))) att...null) (co-occur (nt-n> Gen22) (n> Co-E-of-Count-from-Zero22))) att-tranufer- upecs ((control-env (control-env (nt-n> Gen22)))) doc ("computes the length

  17. Do physico-chemical properties of silver nanoparticles decide their interaction with biological media and bactericidal action? A review.

    PubMed

    Pareek, Vikram; Gupta, Rinki; Panwar, Jitendra

    2018-09-01

    The unprecedented increase in antibiotic resistance in this era has resuscitated the attention of scientific community to exploit silver and its various species as antimicrobial agents. Plenty of studies have been done to measure the antimicrobial potential of silver species (cationic silver, metallic Ag 0 or silver nanoparticles, silver oxide particulates etc.) and indicated that membrane damage, oxidative stress, protein dysfunction and DNA damage to be the possible cause of injury to the microbial cell. However, the precise molecular mechanism of their mode of action has remained unclear, which makes an obstacle towards the generation of potential antibacterial agent against various pathogenic and multidrug resistant (MDR) bacteria. In order to endeavor this issue, one should first have the complete understanding about the resistance mechanisms present in bacteria that can be a therapeutic target for the silver-based drug formulations. Apart from this, in-depth understanding of the interactions of various silver species (with the biological media) is a probable deciding factor for the synthesis of silver-based drug formulations because the particular form and physico-chemical properties of silver can ultimately decide their antimicrobial action. In context to above mentioned serious concerns, the present article aims to discuss the mechanisms behind the confrontation of bacteria against various drugs and the effect of physico-chemical properties of silver species on their bactericidal action as well as critically evaluates the available reports on bacterial transcriptomic and proteomic profiles upon the exposure of various silver species. Further, this review state the mechanism of action that needs to be followed for the complete understanding of toxic potential of silver nanoparticles, which will open a possibility to synthesize new silver nanoparticle based antimicrobial systems with desired properties to ensure their safe use, exposure over extended period and fate in human body and environment. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Three-body wear of a hand-consolidated silver alternative to amalgam.

    PubMed

    Xu, H H; Eichmiller, F C; Giuseppetti, A A; Ives, L K; Parry, E E; Schumacher, G E

    1999-09-01

    Recent studies have investigated a mercury-free silver alternative to amalgam, but the silver powders required a relatively high compaction pressure to consolidate. The aim of the present study was to consolidate a precipitated silver powder into a cohesive solid using an air-driven pneumatic condenser fitted with an amalgam plugger at a clinically realistic load, and to study the mechanisms and rates of three-body wear of the consolidated silver in comparison with that of an amalgam. The silver powder was annealed, rinsed with a dilute acid, and consolidated either in a prepared tooth cavity or in a specimen mold at a load of 15 N. A four-station wear machine was used where each specimen was immersed in a slurry containing polymethyl methacrylate beads, then a steel pin was loaded and rotated against the specimen at a maximum load of 76 N. The flexural strength in MPa (mean +/- SD; n = 10) was 86 +/- 20 for amalgam, 181 +/- 45 for silver with a polished surface, and 202 +/- 21 for silver with a burnished surface. After 4 x 10(5) wear cycles, the wear scar depth in microm was 134 +/- 54 for amalgam, 143 +/- 8 for polished silver, and 131 +/- 9 for burnished silver, which were not significantly different (Tukey's multiple comparison test; family confidence coefficient = 0.95). SEM examination revealed cracks and fracture pits in the worn surface of amalgam, in contrast to a smooth surface in silver. Wear and material removal in amalgam occurred by microfracture and dislodgement of cracked segments, while wear in the silver occurred by ductile deformation and flow of materials. To conclude, the consolidated silver possesses a three-body wear resistance similar to that of amalgam, and a higher resistance to wear-induced damage and cracking than amalgam. The mechanism of wear in amalgam is microfracture and material dislodgement, while that in consolidated silver is ductile deformation and flow of material.

  19. Synthesis and characterization of silver nanoparticles from (bis)alkylamine silver carboxylate precursors.

    PubMed

    Uznanski, Pawel; Zakrzewska, Joanna; Favier, Frederic; Kazmierski, Slawomir; Bryszewska, Ewa

    2017-01-01

    A comparative study of amine and silver carboxylate adducts [R 1 COOAg-2(R 2 NH 2 )] (R 1  = 1, 7, 11; R 2  = 8, 12) as a key intermediate in NPs synthesis is carried out via differential scanning calorimetry, solid-state FT-infrared spectroscopy, 13 C CP MAS NMR, powder X-ray diffraction and X-ray photoelectron spectroscopy, and various solution NMR spectroscopies ( 1 H and 13 C NMR, pulsed field gradient spin-echo NMR, and ROESY). It is proposed that carboxyl moieties in the presence of amine ligands are bound to silver ions via chelating bidentate type of coordination as opposed to bridging bidentate coordination of pure silver carboxylates resulting from the formation of dimeric units. All complexes are packed as lamellar bilayer structures. Silver carboxylate/amine complexes show one first-order melting transition. The evidence presented in this study shows that phase behavior of monovalent metal carboxylates are controlled, mainly, by head group bonding. In solution, insoluble silver salt is stabilized by amine molecules which exist in dynamic equilibrium. Using (bis)amine-silver carboxylate complex as precursor, silver nanoparticles were fabricated. During high-temperature thermolysis, the (bis)amine-carboxylate adduct decomposes to produce silver nanoparticles of small size. NPs are stabilized by strongly interacting carboxylate and trace amounts of amine derived from the silver precursor interacting with carboxylic acid. A corresponding aliphatic amide obtained from silver precursor at high-temperature reaction conditions is not taking part in the stabilization. Combining NMR techniques with FTIR, it was possible to follow an original stabilization mechanism. Graphical abstractThe synthesis of a series (bis)alkylamine silver(I) carboxylate complexes in nonpolar solvents were carried out and fully characterized both in the solid and solution. Carboxyl moieties in the presence of amine ligands are bound to silver ions via chelating bidentate type of coordination. The complexes form layered structures which thermally decompose forming nanoparticles stabilized only by aliphatic carboxylates.

  20. NAVSPASUR System Performance Analysis

    DTIC Science & Technology

    1988-03-16

    I’ 0 0 . a ~ 04 W 4 A ~ 0 0M O a 0 00 00 * ~ ~~ ~~~~~~~~~ 0 O0.1 4 01 U. . M O 6 U- 4444 0 -U U j C 4 ,0u a.* ll0.AO S-4C4U 0 aCCA A aao5 U V U U U...c 0. A O a v ~ N .3 c3 o it @4 66W4 4w 0 4oo 00 N 02 0 . 0. 1. -CI Z. 6- ,n 4 . *, . 444 .2 a.’. 04 ’ 4 - 4 ’.2’ ix -. Id 06 f3 6 6 to . 4 16...8217 U -, 1 0 -4 N 41 - 0 -- 0 4C r 0 -N 0 P 4 4 f3 .4 E 0 04 19 00 C-I 0 ONO.U1 : U U ow 0 0-U .4 > 0 0 a 3; AU " w U b. a. 0. o (0.. 04 09 U 0 k.- 4

  1. Dollar Summary of Federal Supply Classification and Service Category by Company. Part 5 (1005-4810)

    DTIC Science & Technology

    1991-01-01

    L - U . > . > - > L U - > -L - <~~~~ a a L<>>> ><x< <xX< CL~~~~ a . a 0 <<< < 0 w0 0 w = Oi ( >4 -4 .1- zaw 4) - 4 0 0 .4 c0 0a Uo aa-a 4 w cc aw Co a...2)-) 1- m 0 tun t" 0 . w - 0 LU 14 r L U ) 0 D ) 1~ 0. )- 4 -14 Z 14 4 > 0 a o4 5l -c w4 w4 w ~ 00) m) -4 0 C, on N 0 O N40 0 N Nl co " -4 4 m~ sLn 00...II 0 I 4W 4W W -.4 -.4 0 .4 L 4 0 1- I ) -4- C)I I a - W go~~ I W >- ᝾ _j 1: tun I ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 4 I -)r c0 - 0 - (0 D ONt -4 0 m) 0 0 C0

  2. Determination of silver nanoparticle release from antibacterial fabrics into artificial sweat

    PubMed Central

    2010-01-01

    Silver nanoparticles have been used in numerous commercial products, including textiles, to prevent bacterial growth. Meanwhile, there is increasing concern that exposure to these nanoparticles may cause potential adverse effects on humans as well as the environment. This study determined the quantity of silver released from commercially claimed nanosilver and laboratory-prepared silver coated fabrics into various formulations of artificial sweat, each made according to AATCC, ISO and EN standards. For each fabric sample, the initial amount of silver and the antibacterial properties against the model Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria on each fabric was investigated. The results showed that silver was not detected in some commercial fabrics. Furthermore, antibacterial properties of the fabrics varied, ranging from 0% to greater than 99%. After incubation of the fabrics in artificial sweat, silver was released from the different fabrics to varying extents, ranging from 0 mg/kg to about 322 mg/kg of fabric weight. The quantity of silver released from the different fabrics was likely to be dependent on the amount of silver coating, the fabric quality and the artificial sweat formulations including its pH. This study is the unprecedented report on the release of silver nanoparticles from antibacterial fabrics into artificial sweat. This information might be useful to evaluate the potential human risk associated with the use of textiles containing silver nanoparticles. PMID:20359338

  3. Gold and silver nanoparticles from Trianthema decandra: synthesis, characterization, and antimicrobial properties

    PubMed Central

    Geethalakshmi, R; Sarada, DVL

    2012-01-01

    Background There is an increasing commercial demand for nanoparticles due to their wide applicability in various markets, including medicine, catalysis, electronics, chemistry, and energy. In this report, a simple and ecofriendly chemical reaction for the synthesis of gold and silver nanoparticles from Trianthema decandra (Aizoaceae) has been developed. Methods and results On treatment of aqueous solutions containing chloroauric acid or silver nitrate with root extract of T. decandra, stable gold or silver nanoparticles were rapidly formed. The kinetics of reduction of gold and silver ions during the reaction was analyzed by ultraviolet-visible spectroscopy. Field emission-scanning electron microscopy showed formation of gold nanoparticles in various shapes, including spherical, cubical, triangular, and hexagonal, while silver nanoparticles were spherical. The size of the gold nanoparticles was 33–65 nm and that of the silver nanoparticles was 36–74 nm. Energy dispersive x-ray and Fourier transform infrared spectroscopy confirmed the presence of metallic gold and metallic silver in the respective nanoparticles. The antimicrobial properties of the synthesized nanoparticles were analyzed using the Kirby-Bauer method. The results show varied susceptibility of microorganisms to the gold and silver nanoparticles. Conclusion It is believed that phytochemicals present in T. decandra extract reduce the silver and gold ions into metallic nanoparticles. This strategy reduces the cost of production and the environmental impact. The silver and gold nanoparticles formed showed strong activity against all microorganisms tested. PMID:23091381

  4. Effect of Silver Flakes in Silver Paste on the Joining Process and Properties of Sandwich Power Modules (IGBTs Chip/Silver Paste/Bare Cu)

    NASA Astrophysics Data System (ADS)

    Zhao, Su-Yan; Li, Xin; Mei, Yun-Hui; Lu, Guo-Quan

    2016-11-01

    In this study, a silver paste has been introduced for attaching chips onto bare Cu substrates (without coating) without applying pressure. Small nano-thickness Ag flakes, measuring 1 μm-5 μm length, were embedded uniformly in Ag nanoparticles for improving the density of the material. The presence of silver flakes in the silver paste affected the joining process and its microstructure. Microstructure characterization revealed that densification of the silver layer was affected by the presence of silver flakes as the flakes coarsened and formed reactive in situ nanoparticles, which facilitated the sintering between the flakes and the incorporated nanoparticles. Coarsening of silver flakes depended on the sintering temperature, time, and the atmosphere, which affected the decomposition and burning out of organics presented on the surface of the flakes. A high-density silver layer was obtained due to the presence of compact silver flakes. With an increase in the microstructure density, a higher bonding strength and a lower thermal impedance of the sintered joints were achieved. On performing pressureless sintering at 270°C for 30 min under 99.99% N2 or 4% H2/N2, the bonding strength and thermal impedance for 11 × 11 mm2 chips were excellent, measuring approximately 21.9 MPa and 0.077°C/W, respectively.

  5. Synthesis and characterization of colloidal fluorescent silver nanoclusters.

    PubMed

    Huang, Sherry; Pfeiffer, Christian; Hollmann, Jana; Friede, Sebastian; Chen, Justin Jin-Ching; Beyer, Andreas; Haas, Benedikt; Volz, Kerstin; Heimbrodt, Wolfram; Montenegro Martos, Jose Maria; Chang, Walter; Parak, Wolfgang J

    2012-06-19

    Ultrasmall water-soluble silver nanoclusters are synthesized, and their properties are investigated. The silver nanoclusters have high colloidal stability and show fluorescence in the red. This demonstrates that like gold nanoclusters also silver nanoclusters can be fluorescent.

  6. Synthesis, characterization and catalytic activity of silver nanoparticles using Tribulus terrestris leaf extract.

    PubMed

    Ashokkumar, S; Ravi, S; Kathiravan, V; Velmurugan, S

    2014-01-01

    Biomediated silver nanoparticles were synthesized with the aid of an eco-friendly biomaterial, namely, aqueous Tribulus terrestris extract. Silver nanoparticles were synthesized using a rapid, single step, and completely green biosynthetic method employing aqueous T. terrestris leaf extracts as both the reducing and capping agent. Silver ions were rapidly reduced by aqueous T. terrestris leaf extracts, leading to the formation of highly crystalline silver nanoparticles. An attempt has been made and formation of the silver nanoparticles was verified by surface plasmon spectra using an UV-vis (Ultra violet), spectrophotometer. Morphology and crystalline structure of the prepared silver nanoparticles were characterized by TEM (Transmission Electron Microscope) and XRD (X-ray Diffraction), techniques, respectively. FT-IR (Fourier Transform Infrared), analysis suggests that the obtained silver nanoparticles might be stabilized through the interactions of carboxylic groups, carbonyl groups and the flavonoids present in the T. terrestris extract. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Green synthesis and characterization of silver nanoparticles using alcoholic flower extract of Nyctanthes arbortristis and in vitro investigation of their antibacterial and cytotoxic activities.

    PubMed

    Gogoi, Nayanmoni; Babu, Punuri Jayasekhar; Mahanta, Chandan; Bora, Utpal

    2015-01-01

    Here we report the synthesis of silver nanoparticles using ethanolic flower extract of Nyctanthes arbortristis, UVvisible spectra and TEM indicated the successful formation of silver nanoparticles. Crystalline nature of the silver nanoparticles was confirmed by X-ray diffraction. Fourier Transform Infra-Red Spectroscopy analysis established the capping of the synthesized silver nanoparticles with phytochemicals naturally occurring in the ethanolic flower extract of N. arbortristis. The synthesized silver nanoparticles showed antibacterial activity against the pathogenic strain of Escherichia coli MTCC 443. Furthermore, cytotoxicity of the silver nanoparticles was tested on mouse fibroblastic cell line (L929) and found to be non-toxic, which thus proved their biocompatibility. Antibacterial activity and cytotoxicity assay carried out in this study open up an important perspective of the synthesized silver nanoparticles. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Interaction of DNA bases with silver nanoparticles: assembly quantified through SPRS and SERS.

    PubMed

    Basu, Soumen; Jana, Subhra; Pande, Surojit; Pal, Tarasankar

    2008-05-15

    Colloidal silver nanoparticles were prepared by reducing silver nitrate with sodium borohydride. The synthesized silver particles show an intense surface plasmon band in the visible region. The work reported here describes the interaction between nanoscale silver particles and various DNA bases (adenine, guanine, cytosine, and thymine), which are used as molecular linkers because of their biological significance. In colloidal solutions, the color of silver nanoparticles may range from red to purple to orange to blue, depending on the degree of aggregation as well as the orientation of the individual particles within the aggregates. Transmission electron microscopy (TEM), X-ray diffraction (XRD), and absorption spectroscopy were used to characterize the assemblies. DNA base-induced differential silver nanoparticle aggregation was quantified from the peak separation (relates to color) of surface plasmon resonance spectroscopy (SPRS) and the signal intensity of surface-enhanced Raman scattering (SERS), which rationalize the extent of silver-nucleobase interactions.

  9. Facile chemical routes to mesoporous silver substrates for SERS analysis

    PubMed Central

    Tastekova, Elina A; Polyakov, Alexander Yu; Goldt, Anastasia E; Sidorov, Alexander V; Oshmyanskaya, Alexandra A; Sukhorukova, Irina V; Shtansky, Dmitry V; Grünert, Wolgang

    2018-01-01

    Mesoporous silver nanoparticles were easily synthesized through the bulk reduction of crystalline silver(I) oxide and used for the preparation of highly porous surface-enhanced Raman scattering (SERS)-active substrates. An analogous procedure was successfully performed for the production of mesoporous silver films by chemical reduction of oxidized silver films. The sponge-like silver blocks with high surface area and the in-situ-prepared mesoporous silver films are efficient as both analyte adsorbents and Raman signal enhancement mediators. The efficiency of silver reduction was characterized by X-ray diffraction and X-ray photoelectron spectroscopy. The developed substrates were applied for SERS detection of rhodamine 6G (enhancement factor of about 1–5 × 105) and an anti-ischemic mildronate drug (meldonium; enhancement factor of ≈102) that is known for its ability to increase the endurance performance of athletes. PMID:29600149

  10. Preparation and characterization of silver nanoparticles homogenous thin films

    NASA Astrophysics Data System (ADS)

    Hegazy, Maroof A.; Borham, E.

    2018-06-01

    The wet chemical method by metal salt reduction has been widely used to synthesize nanoparticles. Accordingly the silver nitrate used as silver precursor and sodium borohydrate as reduction agent. The silver nanoparticles were characterized by different characterization techniques including UV-VIS spectrometry, Transmission electron microscope (TEM), and Zeta potential technique. Thin films of the colloidal solution were fabricated using direct precipitation technique on ITO glass, silicon substrate and commercial glass substrate and characterized by imaging technique. The absorption peak of the silver nanoparticles colloidal solution was around 400 nm. The TEM images indicate that the silver nanoparticles had spherical shape and their sizes were from 10 to 17 nm. The particle size of the silver nanoparticles was confirmed by Zeta potential technique. The imaging technique indicated that the homogeneous distribution of the colloidal silver solution thin film on the silicon substrate was stronger than the ITO glass and inhomogeneous film was emerged on the commercial glass.

  11. Synthesis of silver nanoparticles in melts of amphiphilic polyesters

    NASA Astrophysics Data System (ADS)

    Vasylyev, S.; Damm, C.; Segets, D.; Hanisch, M.; Taccardi, N.; Wasserscheid, P.; Peukert, W.

    2013-03-01

    The current work presents a one-step procedure for the synthesis of amphiphilic silver nanoparticles suitable for production of silver-filled polymeric materials. This solvent free synthesis via reduction of Tollens’ reagent as silver precursor in melts of amphiphilic polyesters consisting of hydrophilic poly(ethylene glycol) blocks and hydrophobic alkyl chains allows the production of silver nanoparticles without any by-product formation. This makes them especially interesting for the production of medical devices with antimicrobial properties. In this article the influences of the chain length of the hydrophobic block in the amphiphilic polyesters and the process temperature on the particle size distribution (PSD) and the stability of the particles against agglomeration are discussed. According to the results of spectroscopic and viscosimetric investigations the silver precursor is reduced to elemental silver nanoparticles by a single electron transfer process from the poly(ethylene glycol) chain to the silver ion.

  12. Extracellular biosynthesis of silver nanoparticles using the fungus Fusarium semitectum

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

    Basavaraja, S.; Balaji, S.D.; Department of Chemistry, Gulbarga University, Gulbarga 585106, Karnataka

    2008-05-06

    Development of environmental friendly procedures for the synthesis of metal nanoparticles through biological processes is evolving into an important branch of nanobiotechnology. In this paper, we report on the use of fungus 'Fusarium semitectum' for the extracellular synthesis of silver nanoparticles from silver nitrate solution (i.e. through the reduction of Ag{sup +} to Ag{sup 0}). Highly stable and crystalline silver nanoparticles are produced in solution by treating the filtrate of the fungus F. semitectum with the aqueous silver nitrate solution. The formations of nanoparticles are understood from the UV-vis and X-ray diffraction studies. Transmission electron microscopy of the silver particlesmore » indicated that they ranged in size from 10 to 60 nm and are mostly spherical in shape. Interestingly the colloidal suspensions of silver nanoparticles are stable for many weeks. Possible medicinal applications of these silver nanoparticles are envisaged.« less

  13. Recreation Carrying Capacity Facts and Considerations. Report 11. Surry Mountain Lake Project Area.

    DTIC Science & Technology

    1980-07-01

    contributions of practical experience and knowledge , along with their assistance in arranging schedules, have made this carrying capacity research effort...This survey obtained six responses from boaters and water- skiers . 29 A~ .~ ~ ~ ~ ~ ~ ~ ~~~~~~~PEEI PAG ... ._DIAN.K+.+.+ 3+ ,.+ -,++ + _-NO FILM...User characteristics Table 17 indicates the characteristics of the boaters and water- skiers surveyed at Surry. The small sample size at

  14. Campylobacter Immunity and Quantitative Excretion Rates in Thai Children

    DTIC Science & Technology

    1993-01-01

    vitro studies suggest that other pathogens, in- excluded if the diarrhea had lasted >3 days or jfthe patient had C 0 ~~~~~~~recently received...antibiotics. Age.smtsadciclancluding Shigella and Salmonella species and Escherichia coli. . . symptoms. and clinical and treatment data were recorded, and...ubiq- static cellulitic lesions progressing to bullae formation, skin uitous in the estuarine environment. It can cause a syndrome necrosis, necrotizin

  15. Efficient Isolation and Propagation of Human Immunodeficiency Virus on Recombinant Colony-Stimulating Factor 1-Treated Monocytes

    DTIC Science & Technology

    1988-04-01

    search Library /Reprint Deor.: renc Dept of Iimunology, Wasington, DC 20307-5100 Washington, DC: 20�-5100, Ba NAVE OF FNING, SPONSORING an )::Z C- S VBOL...released~~O into)int cultures \\luids wauheeigy na clox Mooc ~es hr ncaly ifeced 4(1 i) ith11 V- (pate IND20A~. second J~pas- sage)~ ~ ~ ~ ~ ~~~~~(l intill

  16. Installation Restoration Program. Phase II. Confirmation/Quantification Stage I.

    DTIC Science & Technology

    1986-02-24

    Drilling and sampling three...borings at Site 8; o Drilling and sampling three borings at Site 11; and o Drilling and sampling three borings at Site 12. The ground water samples...8217-"~~~~~~.."." . " -’ - . .. . ;’ "..-. ’,"",,.- - -".-" - ’ -- -... ... ~ -. . ... ... " " 1 *. Sites Recommended Action Rationale U 8 Drill and sample one background To estimate

  17. Characterization of Bacteria Found in Metal-Working Fluids and the Waste Treatment System Involved in Degradation of Waste Water

    DTIC Science & Technology

    1991-01-01

    weණa1’’ 9A �U a 9wow q0.,cto n !mw ~p~js wg&Ar "Cl W IIE9419 Mtkb*#1SII’ Suco PUG~~~~~ ~~~ RE"~U@ 49O 5 9.99 9 p0!!~ 9 7 ’ 4’ 4qC 64 0

  18. Trans World Tidal Gravity Profile.

    DTIC Science & Technology

    1976-12-01

    LABORATORY AIR FORCE SYSTEMS COMMAN D __ UNITEI) STATES AIR FO RC E HANSCOIVI AFB , MASSACHUSETTS 0173 1 ‘ S ~~~~~ V — (~~~) REPORT DOCUMENTATION PAGE...the fundamental station established at Canberra. Uniformity is maintained with the Brussels fundamental station. It is assessed that the...as well as Canberra and Alice Springs still operatin ~; in 1976. Four new stations are described here Kuala Lumpur (~ a1a’~sja) The gravimeter

  19. Remedial Investigation Report, Presidio Main Installation, Presidio of San Francisco. Volume 2: Tables

    DTIC Science & Technology

    1997-01-01

    00 - rIr N - 0%I 0- )0 - - ci co .0~~R- OzG )~~.~ oj "cj > C- g 0 Eý .•°••o °°°••••"•• , 00~~ 00000 zz z- N - Lf) 1 %D -W 0 LO lOC14 C’.2 a) mn H~c

  20. Differences in patient selection and outcomes between SilverHawk atherectomy and laser ablation in the treatment of femoropopliteal in-stent restenosis: a retrospective analysis from a single center.

    PubMed

    Shammas, Nicolas W; Shammas, Gail A; Jerin, Michael

    2013-12-01

    To analyze differences in the application and outcomes of SilverHawk atherectomy (SH) and excimer laser ablation (ELA) in the treatment of femoropopliteal in-stent restenosis (ISR) in an unselected cohort of patients treated at a single center. Between January 2005 and June 2010, 81 consecutive patients (46 men; mean age 69.1 years, range 43-86) underwent directional atherectomy (41 SH, 40 ELA) for femoropopliteal ISR lesions. Data were reviewed retrospectively on procedural outcomes, major adverse events, and 1-year target lesion revascularization (TLR) obtained from medical records and supplemented with telephone calls. The primary endpoint was symptom-driven TLR at 1 year; secondary endpoints were death and amputation. ELA was utilized more frequently than SH in longer lesions (210.4±104 vs. 126.2±79.3 mm, respectively; p=0.001), subacute presentation (55% vs. 14.6%, p=0.001), TASC D lesions (47.5% vs. 12.2%), and in patients with more angiographic thrombus (42.5% vs. 4.9%, p=0.001). Final angiographic success (<30% residual narrowing post final treatment) was similar between ELA and SH (92.5% vs. 100%, respectively, p=0.12). Bailout stenting was significantly higher with ELA vs. SH (50.0% vs. 24.4%, p=0.022). At 1 year, TLR had occurred in 48.7% of the ELA patients vs. 31.7% of the SH cases (p=0.171). Regression analysis confirmed that SH was a predictor of TLR at 1 year (hazard ratio 2.679, 95% CI 1.015 to 7.073, p=0.047). Both SH and ELA continue to have a high TLR rate in treating ISR of the femoral and popliteal arteries. A higher rate of delayed failure is seen with SH and an earlier, steeper loss of TLR-free survival is seen with ELA.

  1. Genomic and transcriptomic comparison of allergen and silver nanoparticle-induced mast cell degranulation reveals novel non-immunoglobulin E mediated mechanisms.

    PubMed

    Johnson, Monica; Alsaleh, Nasser; Mendoza, Ryan P; Persaud, Indushekhar; Bauer, Alison K; Saba, Laura; Brown, Jared M

    2018-01-01

    Mast cells represent a crucial cell type in host defense; however, maladaptive responses are contributing factors in the pathogenesis of allergic diseases. Previous work in our laboratory has shown that exposure to silver nanoparticles (AgNPs) results in mast cell degranulation via a non-immunoglobulin E (IgE) mechanism. In this study, we utilized a systems biology approach to identify novel genetic factors playing a role in AgNP-induced mast cell degranulation compared to the classical activation by antigen-mediated FcεRI crosslinking. Mast cell degranulation was assessed in bone marrow-derived mast cells isolated from 23 strains of mice following exposure to AgNPs or FcεRI crosslinking with dinitrophenyl (DNP). Utilizing strain-dependent mast cell degranulation, an association mapping study identified 3 chromosomal regions that were significantly associated with mast cell degranulation by AgNP and one non-overlapping region associated with DNP-mediated degranulation. Two of the AgNP-associated regions correspond to genes previously reported to be associated with allergic disorders (Trac2 on chromosome 1 and Traf6 on chromosome 2) and an uncharacterized gene identified on chromosome 1 (Fam126b). In conjunction, RNA-sequencing performed on mast cells from the high and low responder strains revealed 3754 and 34 differentially expressed genes that were unique to DNP and AgNP exposures, respectively. Select candidate genes include Ptger4, a gene encoding a G-protein coupled receptor in addition to a multifunctional adaptor protein, Txnip, that may be driving mast cell degranulation by AgNP. Taken together, we identified novel genes that have not been previously shown to play a role in nanoparticle-mediated mast cell activation. With further functional evaluation in the future, these genes may be potential therapeutic targets in the treatment of non-IgE mediated mast cell-linked disorders.

  2. A Universal Aptamer Chimera for the Delivery of Functional microRNA-126.

    PubMed

    Rohde, Jan-H; Weigand, Julia E; Suess, Beatrix; Dimmeler, Stefanie

    2015-06-01

    microRNAs (miRs) regulate vascular diseases such as atherosclerosis and cancer. miR-126 is important for endothelial cell signaling and promotes angiogenesis, protects against atherosclerosis, and reduces breast cancer cell growth and metastasis. The overexpression of miR-126, therefore, may be an attractive therapeutic strategy for the treatment of cardiovascular disease or cancer. Here we report a novel strategy to deliver miR-126 to endothelial and breast cancer cells. We tested three different strategies to deliver miR-126 by linking the miR to an aptamer for the ubiquitously expressed transferrin receptor (transferrin receptor aptamer, TRA). Linking the precursor of miR-126 (pre-miR-126) to the TRA by annealing of a complementary stick led to efficient uptake and processing of miR-126, resulting in the delivery of 1.6×10(6)±0.3×10(6) copies miR-126-3p per ng RNA in human endothelial cells and 7.4×10(5)±2×10(5) copies miR-126-3p per ng in MCF7 breast cancer cells. The functionality of the active TRA-miR-126 chimera was further demonstrated by showing that the chimera represses the known miR-126 target VCAM-1 and improved endothelial cell sprouting in a spheroid assay. Moreover, the TRA-miR-126 chimera reduced proliferation and paracrine endothelial cell recruitment of breast cancer cells to a similar extent as miR-126-3p mimics introduced by conventional liposome-based transfection. Together, this data demonstrates that pre-miR-126 can be delivered by a non-specific aptamer to exert biological functions in two different cell models. The use of the TRA-miR-126 chimera or the combination of the delivery strategy with other endothelial or tumor specific aptamers may provide an interesting therapeutic option to treat vascular disease or cancers.

  3. Silver Nanoparticle Storage Stability in Aqueous and Biological Media

    DTIC Science & Technology

    2015-06-22

    silver nanoparticle stability from the point of synthesis to the point of testing. The recommended conditions of water storage at 4°C protected from... silver nanoparticle formulation for fabrication. (Report No. 2014-73). 13 Métraux, G. S. & Mirkin, C. A. Rapid thermal synthesis of silver ...NAVAL MEDICAL RESEARCH UNIT SAN ANTONIO SILVER NANOPARTICLE STORAGE STABILITY IN AQUEOUS AND BIOLOGICAL MEDIA NATALIE A

  4. MX Siting Investigation. Mineral Resources Survey, Seven Additional Valleys, Nevada/Utah Siting Area. Volume IV.

    DTIC Science & Technology

    1981-06-23

    Lead, copper , silver In brecciated Devonian (?) limestone at the contact with altered grane* Porphyry (507). Silver, lead, copper , gold. Silver, lead...rhyolite and latite. Molybdenum- quartz yamns and disseminated in quartz monaonilte porphyry ( 402) Silveir, gold, lead, Silver, gold, lead, copper ...in parentheses ) Canyon) Tfungsten, gold. silver Tungsten -irregular pipelike bodies in brocaiated and silicified copper , lead. flourspar liniestone

  5. Method for Reduction of Silver Biocide Plating on Metal Surfaces

    NASA Technical Reports Server (NTRS)

    Steele, John; Nalette, Timothy; Beringer, Durwood

    2013-01-01

    Silver ions in aqueous solutions (0.05 to 1 ppm) are used for microbial control in water systems. The silver ions remain in solution when stored in plastic containers, but the concentration rapidly decreases to non-biocidal levels when stored in metal containers. The silver deposits onto the surface and is reduced to non-biocidal silver metal when it contacts less noble metal surfaces, including stainless steel, titanium, and nickel-based alloys. Five methods of treatment of contact metal surfaces to deter silver deposition and reduction are proposed: (1) High-temperature oxidation of the metal surface; (2) High-concentration silver solution pre-treatment; (3) Silver plating; (4) Teflon coat by vapor deposition (titanium only); and (5) A combination of methods (1) and (2), which proved to be the best method for the nickel-based alloy application. The mechanism associated with surface treatments (1), (2), and (5) is thought to be the development of a less active oxide layer that deters ionic silver deposition. Mechanism (3) is an attempt to develop an equilibrium ionic silver concentration via dissolution of metallic silver. Mechanism (4) provides a non-reactive barrier to deter ionic silver plating. Development testing has shown that ionic silver in aqueous solution was maintained at essentially the same level of addition (0.4 ppm) for up to 15 months with method (5) (a combination of methods (1) and (2)), before the test was discontinued for nickel-based alloys. Method (1) resulted in the maintenance of a biocidal level (approximately 0.05 ppm) for up to 10 months before that test was discontinued for nickel-based alloys. Methods (1) and (2) used separately were able to maintain ionic silver in aqueous solution at essentially the same level of addition (0.4 ppm) for up to 10 months before the test was discontinued for stainless steel alloys. Method (3) was only utilized for titanium alloys, and was successful at maintaining ionic silver in aqueous solution at essentially the same level of addition (0.4 ppm) for up to 10 months before the test was discontinued for simple flat geometries, but not for geometries that are difficult to Teflon coat.

  6. Annual dose of Taiwanese from the ingestion of 210Po in oysters.

    PubMed

    Lee, Hsiu-wei; Wang, Jeng-Jong

    2013-03-01

    Oysters around the coast of Taiwan were collected, dried, spiked with a (209)Po tracer for yield, digested with concentrated HNO(3) and H(2)O(2), and finally dissolved in 0.5 N HCl. The polonium was then spontaneously deposited onto a silver disc, and the activity of (210)Po was measured using an alpha spectrum analyzer equipped with a silicon barrier detector. Meanwhile, the internal effective dose of (210)Po coming from the intake of oysters by Taiwanese was evaluated. The results of the present study indicate that (210)Po average activity concentrations ranged from 23.4 ± 0.4 to 126 ± 94 Bq kg(-1) of fresh oysters. The oysters coming from Penghu island and Kinmen island regions contain higher concentrations of (210)Po in comparison with oysters from other regions of Taiwan. The value of (210)Po weighted average activity concentrations for all oyster samples studied is 25.9 Bq kg(-1). The annual effective dose of Taiwanese due to the ingestion of (210)Po in oysters was estimated to be 4.1 × 10(-2) mSv y(-1). Copyright © 2013. Published by Elsevier Ltd.

  7. The Kongsberg silver deposits, Norway: Ag-Hg-Sb mineralization and constraints for the formation of the deposits

    NASA Astrophysics Data System (ADS)

    Kotková, Jana; Kullerud, Kåre; Šrein, Vladimír; Drábek, Milan; Škoda, Radek

    2018-04-01

    The Kongsberg silver district has been investigated by microscopy and electron microprobe analysis, focusing primarily on the Ag-Hg-Sb mineralization within the context of the updated mineral paragenesis. The earliest mineralization stage is represented by sulfides, including acanthite, and sulfosalts. Native silver formed initially through breakdown of early Ag-bearing phases and later through influx of additional Ag-bearing fluids and silver remobilization. The first two generations of native silver were separated in time by the formation of Ni-Co-Fe sulfarsenides and the monoarsenide niccolite along rims of silver crystals. The presence of As-free sulfosalts and the absence of di- and tri-arsenides suggest a lower arsenic/sulfur activity ratio for the Kongsberg deposits compared to other five-element deposits. Native silver shows binary Ag-Hg and Ag-Sb solid solutions, in contrast to the ternary Ag-Hg-Sb compositions typical for other deposits of similar type. Antimonial silver together with allargentum, dyscrasite, and pyrargyrite was documented exclusively from the northern area of the district. Elsewhere, the only Sb-bearing minerals are polybasite and tetrahedrite/freibergite. Hg-rich silver (up to 21 wt% Hg) has been documented only in the central-western area. Myrmekite of freibergite and chalcopyrite reflects exsolution from an original Ag-poor tetrahedrite upon cooling, while myrmekite of pyrite and silver, forming through breakdown of low-temperature phases (argentopyrite or lenaite) upon heating, characterizes the Kongsberg silver district. Based on the stabilities of minerals and mineral assemblages, the formation of the silver mineralization can be constrained to temperatures between 180 and 250 °C.

  8. Biomedical potential of silver nanoparticles synthesized from calli cells of Citrullus colocynthis (L.) Schrad.

    PubMed

    Satyavani, K; Gurudeeban, S; Ramanathan, T; Balasubramanian, T

    2011-09-26

    An increasingly common application is the use of silver nanoparticles for antimicrobial coatings, wound dressings, and biomedical devices. In this present investigation, we report, biomedical potential of silver nanopaticles synthesized from calli extract of Citrullus colocynthis on Human epidermoid larynx carcinoma (HEp -2) cell line. The callus extract react with silver nitrate solution confirmed silver nanoparticles synthesis through the steady change of greenish colour to reddish brown and characterized by using FT-IR, AFM. Toxicity on HEp 2 cell line assessed using MTT assay, caspase -3 assay, Lactate dehydrogenase leakage assay and DNA fragmentation assay. The synthesized silver nanoparticles were generally found to be spherical in shape with size 31 nm by AFM. The molar concentration of the silver nanoparticles solution in our present study is 1100 nM/10 mL. The results exhibit that silver nanoparticles mediate a dose-dependent toxicity for the cell tested, and the silver nanoparticles at 500 nM decreased the viability of HEp 2 cells to 50% of the initial level. LDH activities found to be significantly elevated after 48 h of exposure in the medium containing silver nanoparticles when compared to the control and Caspase 3 activation suggested that silver nanoparticles caused cell death through apoptosis, which was further supported by cellular DNA fragmentation, showed that the silver nanoparticles treated HEp2 cells exhibited extensive double strand breaks, thereby yielding a ladder appearance (Lane 2), while the DNA of control HEp2 cells supplemented with 10% serum exhibited minimum breakage (Lane 1). This study revealed completely would eliminate the use of expensive drug for cancer treatment.

  9. In vitro cytotoxity of silver: implication for clinical wound care.

    PubMed

    Poon, Vincent K M; Burd, Andrew

    2004-03-01

    In this study, we look at the cytotoxic effects of silver on keratinocytes and fibroblasts. We have assessed the viability of monolayer cultures using the MTT and BrdU assays. The composition of the culture medium and also the culture technique were modified to assess the effects of culture 'environment' on the susceptibility of the cells to the toxic action of silver. Further in vitro, experiments were performed using tissue culture models to allow cellular behavior in three dimensional planes which more closely simulated in vivo behavior. The silver source was both silver released from silver nitrate solution but also nanocrystalline silver released from a commercially available dressing. The results show that silver is highly toxic to both keratinocytes and fibroblasts in monolayer culture. When using optimized and individualized culture the fibroblasts appear to be more sensitive to silver than keratinocytes. However, when both cell types were grown in the same medium their viability was the same. Using tissue culture models again indicated an 'environmental effect' with decreased sensitivity of the cells to the cytotoxic effects of the silver. Nevertheless in these studies the toxic dose of skin cells ranging from 7 x 10(-4) to 55 x 10(-4)% was similar to that of bacteria. These results suggest that consideration of the cytotoxic effects of silver and silver-based products should be taken when deciding on dressings for specific wound care strategies. This is important when using keratinocyte culture, in situ, which is playing an increasing role in contemporary wound and burn care.

  10. Synthesis and characterization of silver nanoparticles from (bis)alkylamine silver carboxylate precursors

    NASA Astrophysics Data System (ADS)

    Uznanski, Pawel; Zakrzewska, Joanna; Favier, Frederic; Kazmierski, Slawomir; Bryszewska, Ewa

    2017-03-01

    A comparative study of amine and silver carboxylate adducts [R1COOAg-2(R2NH2)] (R1 = 1, 7, 11; R2 = 8, 12) as a key intermediate in NPs synthesis is carried out via differential scanning calorimetry, solid-state FT-infrared spectroscopy, 13C CP MAS NMR, powder X-ray diffraction and X-ray photoelectron spectroscopy, and various solution NMR spectroscopies (1H and 13C NMR, pulsed field gradient spin-echo NMR, and ROESY). It is proposed that carboxyl moieties in the presence of amine ligands are bound to silver ions via chelating bidentate type of coordination as opposed to bridging bidentate coordination of pure silver carboxylates resulting from the formation of dimeric units. All complexes are packed as lamellar bilayer structures. Silver carboxylate/amine complexes show one first-order melting transition. The evidence presented in this study shows that phase behavior of monovalent metal carboxylates are controlled, mainly, by head group bonding. In solution, insoluble silver salt is stabilized by amine molecules which exist in dynamic equilibrium. Using (bis)amine-silver carboxylate complex as precursor, silver nanoparticles were fabricated. During high-temperature thermolysis, the (bis)amine-carboxylate adduct decomposes to produce silver nanoparticles of small size. NPs are stabilized by strongly interacting carboxylate and trace amounts of amine derived from the silver precursor interacting with carboxylic acid. A corresponding aliphatic amide obtained from silver precursor at high-temperature reaction conditions is not taking part in the stabilization. Combining NMR techniques with FTIR, it was possible to follow an original stabilization mechanism.

  11. Step-reduced synthesis of starch-silver nanoparticles.

    PubMed

    Raghavendra, Gownolla Malegowd; Jung, Jeyoung; Kim, Dowan; Seo, Jongchul

    2016-05-01

    In the present process, silver nanoparticles were directly synthesized in a single step by microwave irradiation of a mixture of starch, silver nitrate, and deionized water. This is different from the commonly adopted procedure for starch-silver nanoparticle synthesis in which silver nanoparticles are synthesized by preparing a starch solution as a reaction medium first. Thus, the additional step associated with the preparation of the starch solution was eliminated. In addition, no additional reducing agent was utilized. The adopted method was facile and straight forward, affording spherical silver nanoparticles with diameter below 10nm that exhibited good antibacterial activity. Further, influence of starch on the size of the silver nanoparticles was noticed. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Preparation of silver nanoparticles at low temperature

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

    Mishra, Mini, E-mail: mishramini5@gmail.com; Chauhan, Pratima, E-mail: mangu167@yahoo.co.in

    Silver from ancient time is used as antimicrobial agent in the bulk form but now with the advancement in nanotechnology silver in the form of nanoparticles shown potential effect against microbes which make us easy to fight with many diseases plants and animals. In this work silver nanoparticles were synthesized by chemical routes using sodium borohydride as reducing agent at low temperature. The particles were characterized through UV-Visible spectroscopy as well as X-Ray Diffraction. The UV-visible spectra of silver nanoparticles exhibited absorption at 425 cm; the crystallite size of the particles is between 19nm to 39nm. EDAX graph shows two peaksmore » of silver and oxygen. Water absorbed by silver nanoparticles was removed by the calcinations.« less

  13. Preparation of silver-activated zinc sulfide thin films

    NASA Technical Reports Server (NTRS)

    Feldman, C.; Swindells, F. E.

    1968-01-01

    Silver improves luminescence and reduces contamination of zinc sulfide phosphors. The silver is added after the zinc sulfide phosphors are deposited in thin films by vapor evaporation, but before calcining, by immersion in a solution of silver salt.

  14. 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...

  15. Recent development in deciphering the structure of luminescent silver nanodots

    NASA Astrophysics Data System (ADS)

    Choi, Sungmoon; Yu, Junhua

    2017-05-01

    Matrix-stabilized silver clusters and stable luminescent few-atom silver clusters, referred to as silver nanodots, show notable difference in their photophysical properties. We present recent research on deciphering the nature of silver clusters and nanodots and understanding the factors that lead to variations in luminescent mechanisms. Due to their relatively simple structure, the matrix-stabilized clusters have been well studied. However, the single-stranded DNA (ssDNA)-stabilized silver nanodots that show the most diverse emission wavelengths and the best photophysical properties remain mysterious species. It is clear that their photophysical properties highly depend on their protection scaffolds. Analyses from combinations of high-performance liquid chromatography, inductively coupled plasma-atomic emission spectroscopy, electrophoresis, and mass spectrometry indicate that about 10 to 20 silver atoms form emissive complexes with ssDNA. However, it is possible that not all of the silver atoms in the complex form effective emission centers. Investigation of the nanodot structure will help us understand why luminescent silver nanodots are stable in aqueous solution and how to further improve their chemical and photophysical properties.

  16. Stability of colloidal silver nanoparticles trapped in lipid bilayer: effect of lecithin concentration and applied temperature.

    PubMed

    Barani, Hossein; Montazer, Majid; Braun, Hans-Georg; Dutschk, Victoria

    2014-12-01

    The use of silver nanoparticle on various substrates has been widespread because of its good antibacterial properties that directly depend on the stability of the silver nanoparticles in a colloidal suspension. In this study, the colloidal solutions of the silver nanoparticles were synthesised by a simple and safe method by using lecithin as a stabilising agent and their stability was examined at various temperatures. The effect of the lecithin concentrations on the stability of the synthesised silver nanoparticles was examined from 25 to 80°C at 5°C intervals, by recording the changes in the UV-vis absorption spectra, the hydrodynamic diameter and the light scattering intensity of the silver nanoparticles. In addition, the morphology of the synthesised silver nanoparticles was investigated with the low-voltage scanning electron microscopy and transmission electron microscopy. The results indicated that increasing temperature caused different changes in the size of the stabilised and the unstabilised silver nanoparticles. The size of the stabilised silver nanoparticles reduced from 38 to 36 nm during increasing temperature, which confirmed good stability.

  17. An environmentally benign antimicrobial nanoparticle based ...

    EPA Pesticide Factsheets

    Silver nanoparticles have antibacterial properties but their use has been a cause for concern because they persist in the environment. Here we show that lignin nanoparticles infused with silver ions and coated with a cationic polyelectrolyte layer form a biodegradable and green alternative to silver nanoparticles. The polyelectrolyte layer promotes the adhesion of the particles to bacterial cell membranes and together with silver ions can kill a broad spectrum of bacteria, including Escherichia coli, Pseudomonas aeruginosa and quaternary-amine-resistant Ralstonia sp. Ion depletion studies showed that the bioactivity of these nanoparticles is time-limited because of the desorption of silver ions. High-throughput bioactivity screening did not reveal increased toxicity of the particles when compared to an equivalent mass of metallic silver nanoparticles or silver nitrate solution. Our results demonstrate that the application of green chemistry principles may allow the synthesis of nanoparticles with biodegradable cores that have higher antimicrobial activity and smaller environmental impact than metallic silver nanoparticles. Our results demonstrate that the application of green chemistry principles may allow the synthesis of nanoparticles with biodegradable cores that have higher antimicrobial activity and smaller environmental impact than metallic silver nanoparticles

  18. Synthesis and Characterization of Composite Hydroxyapatite-Silver Nanoparticles

    NASA Astrophysics Data System (ADS)

    Charlena; Nuzulia, N. A.; Handika

    2017-03-01

    Hydroxyapatite (HAp) is commonly used as bone implant coating recently; however, the material has disadvantage such as lack of antibacterial properties, that can cause an bacterial infection. Addition of silver nanoparticles is expected to be able to provide antibacterial properties. Silver nanoparticles was obtained by reduction of AgNO3 using glucose monohydrate with microwave heating at 100p for 4 minutes. The composite of hydroxyapatite-silver nanoparticles was synthesized using chemical methods by coprecipitation suspension of Ca(OH)2 with (NH4)HPO4, followed by adding silver nanoparticles solution. The size of the synthesized silver nanoparticles was 30-50 nm and exhibited good antibacterial activity. Nevertheless, when it was composited with HAp to form HAp-AgNPs, there was no antibacterial activity due to very low concentration of silver nanoparticles. This was indicated by the absence of silver nanoparticles diffraction patterns. Infrared spectra indicated the presence of chemical shift and the results of scanning electron microscope showed size of the HAp-AgNPs composite was smaller than that of the HAp. This showed the interaction between HAp and the silver nanoparticles.

  19. Green Synthesis of Silver Nanoparticles by using Eucalyptus Globulus Leaf Extract

    NASA Astrophysics Data System (ADS)

    Balamurugan, Madheswaran; Saravanan, Shanmugam

    2017-12-01

    A single step eco-friendly, energy efficient and economically scalable green method was employed to synthesize silver nanoparticles. In this work, the synthesis of silver nanoparticles using Eucalyptus globulus leaf extract as reducing and capping agent along with water as solvent at normal room temperature is described. Silver nanoparticles were prepared from aqueous silver nitrate solution by adding the leaf extract. The prepared nanoparticles were characterized by using UV-visible Spectrophotometer, X-ray diffractometer, High Resolution Transmission Electron Microscope (HR-TEM) and Fourier Transform Infrared Spectroscope (FTIS). X-ray diffraction studies brought to light the crystalline nature and the face centered cubic structure of the silver nanoparticles. Using HR-TEM. the nano sizes and morphology of the particles were studied. The mean sizes of the prepared silver nanoparticles ranged from 30 to 36 nm. The density of the particles was tuned by varying the molar ratio of silver nitrate. FTIS studies showed the functional group of organic molecules which were located on the surface of the silver nanoparticles. Originating from the leaf extracts, these organic molecules reduced and capped the particles.

  20. Silver recovery aqueous techniques from diverse sources: Hydrometallurgy in recycling.

    PubMed

    Syed, S

    2016-04-01

    The demand of silver is ever increasing with the advance of the industrialized world, whereas worldwide reserves of high grade silver ores are retreating. However, there exist large stashes of low and lean grade silver ores that are yet to be exploited. The main impression of this work was to draw attention to the most advance technologies in silver recovery and recycling from various sources. The state of the art in recovery of silver from different sources by hydrometallurgical and bio-metallurgical processing and varieties of leaching, cementing, reducing agents, peeling, electro-coagulants, adsorbents, electro-dialysis, solvent extraction, ion exchange resins and bio sorbents are highlighted in this article. It is shown that the major economic driver for recycling of depleted sources is for the recovery of silver. In order to develop an nature-friendly technique for the recovery of silver from diverse sources, a critical comparison of existing technologies is analyzed for both economic viability and environmental impact was made in this amendment and silver ion toxicity is highlighted. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Preparing high-adhesion silver coating on APTMS modified polyethylene with excellent anti-bacterial performance

    NASA Astrophysics Data System (ADS)

    Li, Wenfei; Chen, Yunxiang; Wu, Song; Zhang, Jian; Wang, Hao; Zeng, Dawen; Xie, Changsheng

    2018-04-01

    Silver coating as a broad-spectrum antimicrobial agent was considered to alleviate the inflammation caused by intrauterine device (IUD) in endometrium. In this work, to avoid the damage of silver coating and ensure its antibacterial properties, 3-aminopropyltrimethoxysilane (APTMS) was introduced to modify the polyethylene (PE) substrate for the purpose of improving the adhesion of the silver coating. From the 90° peel test, it could be found that the adhesive strength of silver coating on the APTMS modified PE substrate was nearly 23 times stronger than the silver coating on substrate without surface modification. The dramatically enhanced adhesive strength could be attributed to the formation of continuous chemical bonds between the silver coatings and substrates after surface modification, which had been confirmed by the XPS. Moreover, the standard antibacterial test revealed that the silver coated samples against Staphylococcus aureus (S. aureus) exhibit excellent antibacterial efficacy. Considering the largely enhanced adhesion and the effective antibacterial property, it is reasonable to believe that the silver coating could be considered as a potential candidate for the antibacterial agent in IUD.

  2. The effectiveness of heparin, platelet-rich plasma (PRP), and silver nanoparticles on prevention of postoperative peritoneal adhesion formation in rats.

    PubMed

    Makarchian, Hamid Reza; Kasraianfard, Amir; Ghaderzadeh, Pezhman; Javadi, Seyed Mohammad Reza; Ghorbanpoor, Manoochehr

    2017-01-01

    To assess the effectiveness of heparin, platelet-rich plasma (PRP), and silver nanoparticles on prevention of postoperative adhesion in animal models. Sixty males Albino Wistar rats aged 5 to 6 weeks were classified into five groups receiving none, heparin, PRP, silver nanoparticles, PRP plus silver nanoparticles intraperitoneally. After 2 weeks, the animals underwent laparotomy and the damaged site was assessed for peritoneal adhesions severity. The mean severity scores were 2.5 ± 0.9, 2.16 ± 0.7, 1.5 ± 0.5, 2.66 ± 0.88, and 2.25 ± 0.62 in the control, heparin, PRP, silver and PRP plus silver groups, respectively with significant intergroup difference (p = 0.004). The highest effective material for preventing adhesion formation was PRP followed by heparin and PRP plus silver. Moreover, compared to the controls, only use of PRP was significantly effective, in terms of adhesion severity (p = 0.01) . Platelet-rich plasma alone may have the highest efficacy for preventing postoperative peritoneal adhesions in comparison with heparin, silver nanoparticles and PRP plus silver nanoparticles.

  3. Mooring Motion Correction of SYNOP Central Array Current Meter Data

    DTIC Science & Technology

    1992-01-01

    GRADUA’FE SCHOOL OF OCEANO (;RAPttY UNIVERSITY OF RHODE ISLAND NARRAGANSETT. HHIiODE ISLAND AD-A262 858 DTICIll 111’rijil ELECTE APR I2 1993 -U...8217 . -4 . A~~- - - - E~ ~ I j 4 1~.~ - ~ ~~~~ -j V QNN -14. C e t - - -. a* :~ tw- -*-- so Wf* op 1.t 11 -. - .0- - - - - - - - U 9o do 0 so sol 00 0-00

  4. A Simple Economic Model of Cocaine Production

    DTIC Science & Technology

    1994-01-01

    University of New Mexico Press: Albuquerque (revised editionL 1988 11. "Plan de F*ecucion del Proyecto de Desarrollo Rural Integral del Alto Huallaga...ensuing raw material supplies (an industrial altenative)? This policy is represented in the model by ’Onewould alsohaeummakwbEr de otu of thsenw eprse...tht iemantngpoWAMdualoldi dieweinvesumaitisdie sa.sdietoldieoutpu ~~maahth~~~~ lnu~Ti srpemtdi dwemodelbyaeng diet die tota bacor A~l, ssousud it de nw

  5. Structures to Resist the Effects of Accidential Explosions. Volume 4. Reinforced Concrete Design

    DTIC Science & Technology

    1987-04-01

    menus , however, references are given defining similar procedures for, one-way elements. Procedure: Step 1. Establish design parameters: a. Blast loads...Torsional capacity. 2.4 Kfc )112 t1.v2 1/2 (eq. 4-146) [1 +( u tu A -80 V. 2.4 x (4,000)S~~~~~~~VtC ........... 1 /2 tI 1.2 x 235.2) ] 82.5 142.6 psi

  6. Manufacturing Technology for Nonautoclave Fabrication of Composite Structures

    DTIC Science & Technology

    1985-06-01

    8217• .’’..•’•..• ’’,:••’’’ ’.•’V.:.• ,’’. , ’ . ... ’ ’" ’ " " ’"’" "• " ’"’" ’ .. " " " " " ’ • ’ "" " TABLE XXX COMPONENT NONBOND SIZE DEEC N.DIMENSIONS (INCHES) DEFECT...J4. 0 W CvD I’Z CD - N1 CDV r 09f- W O 0 Ad W~~~~- LU I- 00CN94 E~ =~~~~. c N - 9 - 9.. 01 -~r q-L. - I*5 CYV r edW k14.-U, 00000 0 N4AC~ ~?KVc 0 6 U, I

  7. Global Ocean Tides. Part VIII. The Semidiurnal Luni-Solar Declination Tide (K2), Atlas of Tidal Charts and Maps.

    DTIC Science & Technology

    1981-06-01

    cOOOaaaN.4aO.4a~J aaaa.4’asasSSSasasasasaS ~ 5555 SS 55 5 55*5 5 5555a40.44090.490Sa5555 ’tea aCca -Na SSSCCNNO06440 C.4(40(4’ aaa.tNCA .4.4aaaaOOeaO.4NaSNON...8217f SS .4N’S C CN NN N h . 4 N N N N NNM4 4 nnMf - f n ’ f3 ~~~~~~~~~ C C .40.SNC r foo.N CNC’C*.C N C.N oCoNC CN.𔃺 NSCNNNCCC000000toa, .. o.44.NN N

  8. Worldwide U.S. Active Duty Military Deaths Alphabetical Index by Name. October 1, 1979 through September 30 1992

    DTIC Science & Technology

    1992-09-30

    j 4 c. ZW )---)Z oo zJ ɘ nowo <o L):z E UA caw Z >-4 0 LL o 04a 44) ) 0 040 .x W U, uJl 0 L-a U.. - CL..- OL . 1.- - > Q V U-> L- C QC M >,u o~~ ~ u...34w zx > CL ww 03- O 4 a-4 4 0 ZL i4-4 347 -C 00 < M 30 W > 00 4 wC4C ’t O-l4( La. C ex -4 r- z-4 1- m CL > >0CL> CL.-4 > .-- 4 0.) M - u 4~~~~~~U 0 410

  9. Alpha List of Prime Contract Awards. Oct 92-Sep 93. FY93. (The Barker Rockford Co. - BSN Sport - Germany). Part 3

    DTIC Science & Technology

    1994-03-01

    0 a- 0 %- CL. 0 cc 4 cc -c 0 CL0i: 0 .C5 0 a u 0 u. 0 ~~~r C a - L CieSU 5 5 0U - U ~ 1 ES-~ ~~ ~~ - -UJ U 041...w V V ý U U u w 0 U kaM 0 aO 0 0 0 000 W IlwU 0 . cS w 0 ’. a0 6 - 0 5 ~~~L 0 CQ0 . 0 0 U) 4c 0 a0 41 >- 0 -£ 0 V0 L0 £00 00 CL £ 0 0 #13 ( 0 ’A 4) (n

  10. Distribution of silver in rats following 28 days of repeated oral exposure to silver nanoparticles or silver acetate

    PubMed Central

    2011-01-01

    Background The study investigated the distribution of silver after 28 days repeated oral administration of silver nanoparticles (AgNPs) and silver acetate (AgAc) to rats. Oral administration is a relevant route of exposure because of the use of silver nanoparticles in products related to food and food contact materials. Results AgNPs were synthesized with a size distribution of 14 ± 4 nm in diameter (90% of the nanoparticle volume) and stabilized in aqueous suspension by the polymer polyvinylpyrrolidone (PVP). The AgNPs remained stable throughout the duration of the 28-day oral toxicity study in rats. The organ distribution pattern of silver following administration of AgNPs and AgAc was similar. However the absolute silver concentrations in tissues were lower following oral exposure to AgNPs. This was in agreement with an indication of a higher fecal excretion following administration of AgNPs. Besides the intestinal system, the largest silver concentrations were detected in the liver and kidneys. Silver was also found in the lungs and brain. Autometallographic (AMG) staining revealed a similar cellular localization of silver in ileum, liver, and kidney tissue in rats exposed to AgNPs or AgAc. Using transmission electron microscopy (TEM), nanosized granules were detected in the ileum of animals exposed to AgNPs or AgAc and were mainly located in the basal lamina of the ileal epithelium and in lysosomes of macrophages within the lamina propria. Using energy dispersive x-ray spectroscopy it was shown that the granules in lysosomes consisted of silver, selenium, and sulfur for both AgNP and AgAc exposed rats. The diameter of the deposited granules was in the same size range as that of the administered AgNPs. No silver granules were detected by TEM in the liver. Conclusions The results of the present study demonstrate that the organ distribution of silver was similar when AgNPs or AgAc were administered orally to rats. The presence of silver granules containing selenium and sulfur in the intestinal wall of rats exposed to either of the silver forms suggests a common mechanism of their formation. Additional studies however, are needed to gain further insight into the underlying mechanisms of the granule formation, and to clarify whether AgNPs dissolve in the gastrointestinal system and/or become absorbed and translocate as intact nanoparticles to organs and tissues. PMID:21631937

  11. Polyimides Containing Silver Trifluoroacetylacetonate

    NASA Technical Reports Server (NTRS)

    Stoakley, Diane M.; St. Clair, Anne K.; Rancourt, James D.; Taylor, Larry T.; Caplan, Maggie L.

    1994-01-01

    Mechanically strong, flexible, thermally stable, electrically conductive films and coatings suitable for use in electronics industry made by incorporating silver trifluoroacetylacetonate into linear aromatic condensation polyimides. In experimental films, most successful combinations of flexibility and conductivity obtained by use of 1:1, 1:1.74, and 1:2 mole ratios of silver trifluoroacetylacetonate per polyimide repeat unit. Other concentrations of silver trifluoroacetylacetonate used with different heat-treatment schedules to obtain conductive silver-impregnated films.

  12. Measurements of the optical properties of thin films of silver and silver oxide

    NASA Technical Reports Server (NTRS)

    Peters, Palmer N.; Sisk, Robert C.; Brown, Yolanda; Gregory, John C.; Nag, Pallob K.; Christl, Ligia

    1995-01-01

    The optical properties of silver films and their oxides are measured to better characterize such films for use as sensors for atomic oxygen. Good agreement between properties of measured pure silver films and reported optical constants is observed. Similar comparisons for silver oxide have not been possible because of a lack of reported constants, but self-consistencies and discrepancies in our measured results are described.

  13. Silver ion bactericide system. [for Space Shuttle Orbiter potable water

    NASA Technical Reports Server (NTRS)

    Jasionowski, W. J.; Allen, E. T.

    1974-01-01

    Description of a preliminary flight prototype system which uses silver ions as the bactericide to preserve sterility of the water used for human consumption and hygiene in the Space Shuttle Orbiter. The performance of silver halide columns for passively dosing fuel cell water with silver ions is evaluated. Tests under simulated Orbiter mission conditions show that silver ion doses of 0.05 ppm are bactericidal for Pseudomonas aeruginosa and Type IIIa, the two bacteria found in Apollo potable water systems. The design of the Advance Prototype Silver Ion Water Bactericide System now under development is discussed.

  14. Biomedical properties of laser prepared silver-doped hydroxyapatite

    NASA Astrophysics Data System (ADS)

    Jelínek, M.; Weiserová, M.; Kocourek, T.; Zezulová, M.; Strnad, J.

    2011-07-01

    Thin films of hydroxyapatite (HA) and silver-doped HA were synthesized using KrF excimer laser deposition. Material was ablated from one target composed from silver and HA segments. Layers properties as silver content, structure, color, FTIR spectra and antibacterial properties (Gram-positive Bacillus subtilis) were measured. Silver concentration in HA layers of 0.06, 0.3, 1.2, 4.4, 8.3, and 13.7 at % was detected. The antibacterial efficacy changed with silver dopation from 71.0 to 99.9%. The focus is on investigation of minimum Ag concentration needed to reach a high antibacterial efficacy.

  15. Silver Hazards to Fish, Wildlife, and Invertebrates: A Synoptic Review

    USGS Publications Warehouse

    Eisler, R.

    1996-01-01

    Ecological and toxicological aspects of silver (Ag) in the environment are briefly summarized with an emphasis on natural resources. Elevated silver concentrations in biota occur in the vicinities of sewage outfalls, electroplating plants, mine waste sites, and silver-iodide seeded areas; in the United States, the photography industry is the major source of anthropogenic silver discharges into the biosphere. Silver and its compounds are not known to be mutagenic, teratogenic, or carcinogenic. Under normal routes of exposure, silver does not pose serious environmental health problems to humans at less than 50.0 ug total Ag/L drinking water or 10.0 ug per cubic meter air. Free silver ion, however, was lethal to representative species of sensitive aquatic plants, invertebrates, and teleosts at nominal water concentrations of 1.2 to 4.9 ug/L; sublethal effects were significant between 0.17 and 0.6 ug/L. Silver was harmful to poultry at concentrations as low as 1.8 mg total Ag/kg whole egg fresh weight by way of injection, 100.0 mg total Ag/L in drinking water, or 200.0 mg total Ag/kg in diets; sensitive mammals were adversely affected at total silver concentrations as low as 250.0 ug/L in drinking water, 6.0 mg/kg in diets, or 13.9 mg/kg whole body.

  16. Comparative activity of silver based antimicrobial composites for urinary catheters.

    PubMed

    Thokala, Nikhil; Kealey, Carmel; Kennedy, James; Brady, Damien B; Farrell, Joseph

    2018-04-04

    Biomedical polymers are an integral component in a wide range of medical device designs due to their range of desirable properties. However, extensive use of polymer materials in medical devices have also been associated with an increasing incidence of patient infections. Efforts to address this issue have included the incorporation of antimicrobial additives for developing novel antimicrobial polymeric materials. Silver with its high toxicity towards bacteria, oligodynamic effect and good thermal stability has been employed as an additive for polymeric medical devices. In the present study, commercially available elemental (Biogate) and ionic (Ultrafresh 16) silver additives were incorporated into a Polyamide 11 (PA 11) matrix using a compression press. These polymer composites were evaluated for their antimicrobial and ion release properties. Elemental silver composites were determined to retain their antimicrobial properties for extended periods and actively release silver ions for 84 days; whereas the ionic silver composites lost their ion release activity and therefore antibacterial activity after 56 days. Bacterial log reduction units of 3.87 for ionic silver and 2.41 for elemental silver was identified within 24 hr, when tested in accordance with ISO 22196 test standard; indicating that ionic silver is more efficient for short-term applications compared to elemental silver. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Piper nigrum Leaf and Stem Assisted Green Synthesis of Silver Nanoparticles and Evaluation of Its Antibacterial Activity Against Agricultural Plant Pathogens

    PubMed Central

    Paulkumar, Kanniah; Gnanajobitha, Gnanadhas; Vanaja, Mahendran; Rajeshkumar, Shanmugam; Malarkodi, Chelladurai; Pandian, Kannaiyan; Annadurai, Gurusamy

    2014-01-01

    Utilization of biological materials in synthesis of nanoparticles is one of the hottest topics in modern nanoscience and nanotechnology. In the present investigation, the silver nanoparticles were synthesized by using the leaf and stem extract of Piper nigrum. The synthesized nanoparticle was characterized by UV-vis spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive X-ray analysis (EDAX), and Fourier Transform Infrared Spectroscopy (FTIR). The observation of the peak at 460 nm in the UV-vis spectra for leaf- and stem-synthesized silver nanoparticles reveals the reduction of silver metal ions into silver nanoparticles. Further, XRD analysis has been carried out to confirm the crystalline nature of the synthesized silver nanoparticles. The TEM images show that the leaf- and stem-synthesized silver nanoparticles were within the size of about 7–50 nm and 9–30 nm, respectively. The FTIR analysis was performed to identify the possible functional groups involved in the synthesis of silver nanoparticles. Further, the antibacterial activity of the green-synthesized silver nanoparticles was examined against agricultural plant pathogens. The antibacterial property of silver nanoparticles is a beneficial application in the field of agricultural nanotechnology. PMID:24558336

  18. Silver Recovery and Power Generation from Ammonia Chelated Silver Solution in a Bio-Electrochemical Reactor

    NASA Astrophysics Data System (ADS)

    Ho, N. A. D.; Babel, S.

    2017-06-01

    Silver has valuable features and limited availability, and thus recovery from wastewater or aqueous solutions plays an important role in environmental protection and economic profits. In this study, silver recovery along with power generation and COD removal were investigated in a bio-electrochemical system (BES). The BES comprised of an anode and a cathode chamber which were separated by a cation exchange membrane to prevent the cross-over of electrolytes. During the biological oxidation of acetate as an electron donor in the anode chamber, the reduction of ammonia chelated silver ions as electron acceptors in the cathode side occurred spontaneously. Results showed that a silver recovery of 99% and COD removal efficiency of 60% were achieved at the initial silver concentration of 1,000 mg/L after 48 hours of operation. The power generation improved 4.66%, from 3,618 to 3,795 mW/m3, by adding NaNO3 of 850 mg/L to the catholyte containing 2,000 mg/L of silver ions. Deposits on the cathode surface were characterized using scanning electron microscope (SEM) and energy dispersive X-ray (EDX). Metallic silver with dendritic structures and high purity were detected. This study demonstrated that BES technology can be employed to recover silver from complex chelating solution, produce electricity, and treat wastewater.

  19. Concurrent In Vitro Release of Silver Sulfadiazine and Bupivacaine From Semi-Interpenetrating Networks for Wound Management

    PubMed Central

    Kleinbeck, Kyle R.; Bader, Rebecca A.; Kao, Weiyuan John

    2013-01-01

    In situ photopolymerized semi-interpenetrating networks (sIPNs) composed of poly(ethylene glycol) and gelatin are promising multifunctional matrices for a regenerative medicine approach to dermal wound treatment. In addition to previously demonstrated efficacy in critical defects, sIPNs also function as drug delivery matrices for compounds loaded as either soluble or covalently linked components. Simultaneous release of silver sulfadiazine and bupivacaine from the sIPN would provide multiple-hit management of dermal wounds that minimizes infection, and manages pain along with sIPN absorption of exudates and facilitation of epidermal regrowth. We characterized the release of soluble silver sulfadiazine and bupivacaine and compared it with an established release model. Efficacy of released silver sulfadiazine was confirmed in vitro on Staphylococcus aureus, methicillin resistant S. aureus, and Pseudomonas aeruginosa. Bupivacaine loaded without silver sulfadiazine showed incomplete release, whereas simultaneous loading with silver sulfadiazine facilitated 100% bupivacaine release. Silver sulfadiazine released at 98% without bupivacaine and 96% with bupivacaine. Silver sulfadiazine released onto bacterial cultures inhibited all three strains dose dependently. sIPNs effectively release bupivacaine and silver sulfadiazine while maintaining the antimicrobial activity of silver sulfadiazine. Drug loaded sIPNs have potential to improve wound management by providing multi-drug delivery along with an effective wound treatment. PMID:19060724

  20. Surface-independent antibacterial coating using silver nanoparticle-generating engineered mussel glue.

    PubMed

    Jo, Yun Kee; Seo, Jeong Hyun; Choi, Bong-Hyuk; Kim, Bum Jin; Shin, Hwa Hui; Hwang, Byeong Hee; Cha, Hyung Joon

    2014-11-26

    During implant surgeries, antibacterial agents are needed to prevent bacterial infections, which can cause the formation of biofilms between implanted materials and tissue. Mussel adhesive proteins (MAPs) derived from marine mussels are bioadhesives that show strong adhesion and coating ability on various surfaces even in wet environment. Here, we proposed a novel surface-independent antibacterial coating strategy based on the fusion of MAP to a silver-binding peptide, which can synthesize silver nanoparticles having broad antibacterial activity. This sticky recombinant fusion protein enabled the efficient coating on target surface and the easy generation of silver nanoparticles on the coated-surface under mild condition. The biosynthesized silver nanoparticles showed excellent antibacterial efficacy against both Gram-positive and Gram-negative bacteria and also revealed good cytocompatibility with mammalian cells. In this coating strategy, MAP-silver binding peptide fusion proteins provide hybrid environment incorporating inorganic silver nanoparticle and simultaneously mediate the interaction of silver nanoparticle with surroundings. Moreover, the silver nanoparticles were fully synthesized on various surfaces including metal, plastic, and glass by a simple, surface-independent coating manner, and they were also successfully synthesized on a nanofiber surface fabricated by electrospinning of the fusion protein. Thus, this facile surface-independent silver nanoparticle-generating antibacterial coating has great potential to be used for the prevention of bacterial infection in diverse biomedical fields.

  1. Multi-functional nano silver: A novel disruptive and theranostic agent for pathogenic organisms in real-time

    PubMed Central

    Gopinath, Ponnusamy Manogaran; Ranjani, Anandan; Dhanasekaran, Dharumadurai; Thajuddin, Nooruddin; Archunan, Govindaraju; Akbarsha, Mohammad Abdulkader; Gulyás, Balázs; Padmanabhan, Parasuraman

    2016-01-01

    The present study was aimed at evaluating the fluorescence property, sporicidal potency against Bacillus and Clostridium endospores, and surface disinfecting ability of biogenic nano silver. The nano silver was synthesized using an actinobacterial cell-filtrate. The fluorescence property as well as imaging facilitator potency of this nano silver was verified adopting spectrofluorometer along with fluorescent and confocal laser scanning microscope wherein strong emission and bright green fluorescence, respectively, on the entire spore surface was observed. Subsequently, the endospores of B. subtilis, B. cereus, B. amyloliquefaciens, C. perfringens and C. difficile were treated with physical sporicides, chemical sporicides and nano silver, in which the nano silver brought about pronounced inhibition even at a very low concentration. Finally, the environmental surface-sanitizing potency of nano silver was investigated adopting cage co-contamination assay, wherein vital organs of mice exposed to the nano silver-treated cage did not show any signs of pathological lesions, thus signifying the ability of nano silver to completely disinfect the spore or reduce the count required for infection. Taken these observations together, we have shown the multi-functional biological properties of the nano silver, synthesized using an actinobacterial cell-filtrate, which could be of application in advanced diagnostics, biomedical engineering and therapeutics in the near future. PMID:27666290

  2. Characterisation and potential migration of silver nanoparticles from commercially available polymeric food contact materials.

    PubMed

    Addo Ntim, Susana; Thomas, Treye A; Begley, Timothy H; Noonan, Gregory O

    2015-01-01

    The potential for consumer exposure to nano-components in food contact materials (FCMs) is dependent on the migration of nanomaterials into food. Therefore, characterising the physico-chemical properties and potential for migration of constituents is an important step in assessing the safety of FCMs. A number of commercially available food storage products, purchased domestically within the United States and internationally, that claim to contain nanosilver were evaluated. The products were made of polyethylene, polypropylene and polyphenylene ether sulfone and all contained silver (0.001-36 mg kg(-1) of polymer). Silver migration was measured under various conditions, including using 3% acetic acid and water as food simulants. Low concentrations (sub-ppb levels) of silver were detected in the migration studies generally following a trend characterised by a surface desorption phenomenon, where the majority of the silver migration occurred in the first of three consecutive exposures. Silver nanoparticles were not detected in food simulants, suggesting that the silver migration may be due solely to ionic silver released into solution from oxidation of the silver nanoparticle surface. The absence of detectable silver nanoparticles was consistent with expectations from a physico-chemical view point. For the products tested, current USFDA guidance for evaluating migration from FCMs was applicable.

  3. Evaluation of Osseous Integration of PVD-Silver-Coated Hip Prostheses in a Canine Model

    PubMed Central

    Hauschild, Gregor; Hardes, Jendrik; Gosheger, Georg; Blaske, Franziska; Wehe, Christoph; Karst, Uwe; Höll, Steffen

    2015-01-01

    Infection associated with biomaterials used for orthopedic prostheses remains a serious complication in orthopedics, especially tumor surgery. Silver-coating of orthopedic (mega)prostheses proved its efficiency in reducing infections but has been limited to surface areas exposed to soft tissues due to concerns of silver inhibiting osseous integration of cementless stems. To close this gap in the bactericidal capacity of silver-coated orthopedic prostheses extension of the silver-coating on surface areas intended for osseous integration seems to be inevitable. Our study reports about a PVD- (physical-vapor-deposition-) silver-coated cementless stem in a canine model for the first time and showed osseous integration of a silver-coated titanium surface in vivo. Radiological, histological, and biomechanical analysis revealed a stable osseous integration of four of nine stems implanted. Silver trace elemental concentrations in serum did not exceed 1.82 parts per billion (ppb) and can be considered as nontoxic. Changes in liver and kidney functions associated with the silver-coating could be excluded by blood chemistry analysis. This was in accordance with very limited metal displacement from coated surfaces observed by laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS) 12 months after implantation. In conclusion our results represent a step towards complete bactericidal silver-coating of orthopedic prostheses. PMID:25695057

  4. Understanding long-term silver release from surface modified porous titanium implants.

    PubMed

    Shivaram, Anish; Bose, Susmita; Bandyopadhyay, Amit

    2017-08-01

    Prevention of orthopedic device related infection (ODRI) using antibiotics has met with limited amount of success and is still a big concern during post-surgery. As an alternative, use of silver as an antibiotic treatment to prevent surgical infections is being used due to the well-established antimicrobial properties of silver. However, in most cases silver is used in particulate form with wound dressings or with short-term devices such as catheters but not with load-bearing implants. We hypothesize that strongly adherent silver to load-bearing implants can offer longer term solution to infection in vivo. Keeping that in mind, the focus of this study was to understand the long term release study of silver ions for a period of minimum 6months from silver coated surface modified porous titanium implants. Implants were fabricated using a LENS™ system, a powder based additive manufacturing technique, with at least 25% volume porosity, with and without TiO 2 nanotubes in phosphate buffer saline (pH 7.4) to see if the total release of silver ions is within the toxic limit for human cells. Considering the fact that infection sites may reduce the local pH, silver release was also studied in acetate buffer (pH 5.0) for a period of 4weeks. Along with that, the osseointegrative properties as well as cytotoxicity of porous titanium implants were assessed in vivo for a period of 12weeks using a rat distal femur model. In vivo results indicate that porous titanium implants with silver coating show comparable, if not better, biocompatibility and bonding at the bone-implant interface negating any concerns related to toxicity related to silver to normal cells. The current research is based on our recently patented technology, however focused on understanding longer-term silver release to mitigate infection related problems in load-bearing implants that can even arise several months after the surgery. Prevention of orthopedic device related infection using antibiotics has met with limited success and is still a big concern during post-surgery. Use of silver as an antibiotic treatment to prevent surgical infections is being explored due to the well-established antimicrobial properties of silver. However, in most cases silver is used in particulate form with wound dressings or with short-term devices such as catheters but not with load-bearing implants. We hypothesize that strongly adherent silver to load-bearing implants can offer longer-term solution towards infection in vivo. Keeping that in mind, the focus of this study was to understand the long-term release of silver ions, for a period of minimum 6months, from silver coated surface modified porous titanium implants. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  5. XPS Studies of Doped Polypyrrole Films

    DTIC Science & Technology

    1990-01-25

    XP11 and polymeric, poly(vinylsulfonate) and poly(4- styrensulfonate) anions. Electrostatic interaction between the polymer and the incorporated anions...verbaily, submitted for publication,o3 3S mm ( 2 x2 knjlliep oetor 4w published? "Overhead prolecter Elyes 0 Ne end~~~~~~~ elc oavlblt f te answer Is yes...at characterization with various surface analysis techniques 2 . In the present paper, the authors will describe thL micro- scopic structure of

  6. The FLOW Tutor: Schemas for Tutoring.

    DTIC Science & Technology

    1977-05-01

    1 ~~ Donald R. Gentner Donald A . Norm an THE FLOW TUTOR: SCHEM AS FOR TUTORING H D D C ss~~~ UNIVERSiTY OF CALIFO RNIA , SAN DIEGO LA JOLLA...individualized in— struction , instructional theory, model of the student , representation of information , sc ’ nema , sema ntic ne twork , teaching...I ~~r giving adv ice to a studen t learning ~ simp1e 1~computer language .The tutor has a schema—based knowledge structure

  7. Highly surface-roughened quasi-spherical silver powders in back electrode paste for silicon solar cells

    NASA Astrophysics Data System (ADS)

    Yin, Peng; Liu, Shouchao; Li, Qiuying; Chen, Xiaolei; Guo, Weihong; Wu, Chifei

    2017-08-01

    In our work, highly surface-roughened quasi-spherical silver powders with controllable size and superior dispersibility, which have narrow size distribution and relatively high tap density, were successfully prepared by reducing silver nitrate with ascorbic acid in aqueous solutions. Gum arabic (AG) was selected as dispersant to prevent the agglomeration of silver particles. Furthermore, the effects of preparation conditions on the characteristics of the powders were systematically investigated. By varying the concentration of the reactants, dosage of dispersant, the feeding modes, synthesis temperature and the pH value of the mixture solution of silver nitrate and AG, the resulted silver particles displayed controllable size, different morphologies and surface roughness. The spherical silver powder with mean particle size of 1.20 µm, tap density of 4.1 g cm-3 and specific area value of 0.46 m2 g-1 was prepared by adjusting preparation conditions. The AG absorbed on the surface preventing the silver particles from diffusion and aggregation was proved by the ultraviolet spectra. Observations of SEM images showed that the as-prepared silver powders were relatively monodisperse silver spheres with highly roughened surface and the particle size was controllable from 1 µm to 5 µm, specific surface area value from approximately 0.2 m2 g-1 to 0.8 m2 g-1. X-ray diffraction (XRD) patterns, energy dispersive spectroscopy (EDS), x-ray photoelectron spectra (XPS) and thermal gravity analysis (TGA) demonstrated high crystallinity and purity of the obtained silver powders.

  8. Characterization of Electrochemically Generated Silver

    NASA Technical Reports Server (NTRS)

    Adam, Niklas; Martinez, James; Carrier, Chris

    2014-01-01

    Silver biocide offers a potential advantage over iodine, the current state of the art in US spacecraft disinfection technology, in that silver can be safely consumed by the crew. Low concentrations of silver (<500 ppb) have been shown to kill bacteria in water systems and keep it safe for potability. Silver does not require hardware to remove it from a water system, and therefore can provide a simpler means for disinfecting water. The Russian segment of the International Space Station has utilized an electrochemically generated silver solution, which is colloidal in nature. To be able to reliably provide a silver biocide to drinking water by electrochemical means would reduce mass required for removing another biocide such as iodine from the water. This would also aid in crew time required to replace iodine removal cartridges. Future long term missions would benefit from electrochemically produced silver as the biocide could be produced on demand and requires only a small concentration to be effective. Since it can also be consumed safely, there is less mass in removal hardware and little consumables required for production. The goal of this project initially is to understand the nature of the electrochemically produced silver, the particle sizes produced by the electrochemical cell and the effect that voltage adjustment has on the particle size. In literature, it has been documented that dissolved oxygen and pH have an effect on the ionization of the electrochemical silver so those parameters would be measured and possibly adjusted to understand their effect on the silver.

  9. Printing Silver Nanogrids on Glass

    ERIC Educational Resources Information Center

    Sanders, Wesley C.; Valcarce, Ron; Iles, Peter; Smith, James S.; Glass, Gabe; Gomez, Jesus; Johnson, Glen; Johnston, Dan; Morham, Maclaine; Befus, Elliot; Oz, Aimee; Tomaraei, Mohammad

    2017-01-01

    This manuscript describes a laboratory experiment that provides students with an opportunity to create conductive silver nanogrids using polymeric templates. A microcontact-printed polyvinylpyrrolidone grid directs the citrate-induced reduction of silver ions for the fabrication of silver nanogrids on glass substrates. In addition to…

  10. Absorbent silver (I) antimicrobial fabrics

    USDA-ARS?s Scientific Manuscript database

    In recent years, silver in form of silver ions, has been gaining importance in the wound management as an effective broad-spectrum antimicrobial agent. Silver has a long history as an antimicrobial agent, especially in the treatment of wounds. Alginates and carboxymethyl (CM) cotton contain carboxyl...

  11. Ultralight Conductive Silver Nanowire Aerogels

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

    Qian, Fang; Lan, Pui Ching; Freyman, Megan C.

    Low-density metal foams have many potential applications in electronics, energy storage, catalytic supports, fuel cells, sensors, and medical devices. Here in this work, we report a new method for fabricating ultralight, conductive silver aerogel monoliths with predictable densities using silver nanowires. Silver nanowire building blocks were prepared by polyol synthesis and purified by selective precipitation. Silver aerogels were produced by freeze-casting nanowire aqueous suspensions followed by thermal sintering to weld the nanowire junctions. As-prepared silver aerogels have unique anisotropic microporous structures, with density precisely controlled by the nanowire concentration, down to 4.8 mg/cm 3 and an electrical conductivity up tomore » 51 000 S/m. Lastly, mechanical studies show that silver nanowire aerogels exhibit “elastic stiffening” behavior with a Young’s modulus up to 16 800 Pa.« less

  12. In situ reduction of antibacterial silver ions to metallic silver nanoparticles on bioactive glasses functionalized with polyphenols

    NASA Astrophysics Data System (ADS)

    Ferraris, S.; Miola, M.; Cochis, A.; Azzimonti, B.; Rimondini, L.; Prenesti, E.; Vernè, E.

    2017-02-01

    The realization of surfaces with antibacterial properties due to silver nanoparticles loaded through a green approach is a promising research challenge of the biomaterial field. In this research work, two bioactive glasses have been doubly surface functionalized with polyphenols (gallic acid or natural polyphenols extracted from red grape skins and green tea leaves) and silver nanoparticles deposited by in situ reduction from a silver nitrate aqueous solution. The presence of biomolecules - showing reducing ability to directly obtain in situ metallic silver - and silver nanoparticles was investigated by means of UV-vis spectroscopy, X-Ray Photoelectron Spectroscopy (XPS) and Field Emission Scanning Electron Microscopy (FESEM). The antibacterial activity of the modified surfaces was tested against a multidrug resistant Staphylococcus aureus bacterial strain.

  13. Enhanced photoluminescence of Alq3 via patterned array silver dendritic nanostructures

    NASA Astrophysics Data System (ADS)

    Hsu, Wei-Hsiu; Hsieh, Ming-Hao; Lo, Shih-Shou

    2012-04-01

    Various silver nanostructures, semi-ball, jungle, and dendritic, are demonstrated by an electrical deposition process. The formation of silver nanostructures with various morphologies is studied by the mechanism of the diffusion limited aggregation (DLA) model. A array pattern of silver nanostructures can be obtained when the conductive substrate was used in a uniform electrical filed. A thickness 500 nm of Alq3 thin-film was covered on the silver nanostructure by thermal evaporation method. The strongest intensity of Alq3 green emission was observed when the pattern-array dendritic silver nanostructure was covered by Alq3. It can be explained with the plasmonic coupling due to the Alq3 and dendritic nanostructure. The result can help us to further application the patterned-array silver dendritic nanostructure for advanced opto-electronic device.

  14. Ultralight Conductive Silver Nanowire Aerogels

    DOE PAGES

    Qian, Fang; Lan, Pui Ching; Freyman, Megan C.; ...

    2017-09-05

    Low-density metal foams have many potential applications in electronics, energy storage, catalytic supports, fuel cells, sensors, and medical devices. Here in this work, we report a new method for fabricating ultralight, conductive silver aerogel monoliths with predictable densities using silver nanowires. Silver nanowire building blocks were prepared by polyol synthesis and purified by selective precipitation. Silver aerogels were produced by freeze-casting nanowire aqueous suspensions followed by thermal sintering to weld the nanowire junctions. As-prepared silver aerogels have unique anisotropic microporous structures, with density precisely controlled by the nanowire concentration, down to 4.8 mg/cm 3 and an electrical conductivity up tomore » 51 000 S/m. Lastly, mechanical studies show that silver nanowire aerogels exhibit “elastic stiffening” behavior with a Young’s modulus up to 16 800 Pa.« less

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

    Mendoza-Lopez, M.L.; Centro de Fisica Aplicada y Tecnologia Avanzada, Departamento de Nanotecnologia, Universidad Nacional Autonoma de Mexico, Campus Juriquilla, Apdo. Postal 1-1010, Queretaro Qro. C.P. 76230; Perez-Bueno, J.J.

    This paper presents a complete methodology for the characterization of silver alloys used in modern coin production. Mexican coins with a nominal silver concentration from 10% to 99.99% were used in this study. Calibrated Glow Discharge Optical Emission Spectrometers were used to determine the chemical composition of the alloys as a function of the depth, while inductively coupled plasma was used to determine the total element composition in bulk. Scanning Electron Microscope was used to study the phase distributions in the different silver coins. According to Glow Discharge Optical Emission Spectrometers and inductively coupled plasma, the silver content found inmore » the studied samples was consistently greater than that of the nominal silver content reported by the Mexican mint. This may lead to a review of the new methods of analysis used nowadays in contemporary coin minting. This result is very important because silver is increasing in value as metal and, considering the volume of production of silver coins, this may increase further as a consequence of a growing popular confidence in silver currency. In the case of silver studies, an advantage of the absence of silver detector in the Glow Discharge Optical Emission Spectrometers system is that it allows for the recalibration to have a better range of detection of other metals present in the alloys. A calibration curve using the copper content obtained by inductively coupled plasma (bulk) and Glow Discharge Optical Emission Spectrometers (depth profile) was performed. The relevance of control in modern silver coin minting was clarified, especially in minimizing the discrepancy between the nominal and the core fineness. The physical and chemical properties of the alloys studied are defined, revealing important variations in silver and copper contents. A new methodology and metrology for the control of coinage are suggested.« less

  16. Simulation of the shallow aquifer in the vicinity of Silver Lake, Washington County, Wisconsin, using analytic elements

    USGS Publications Warehouse

    Dunning, C.P.; Thomas, Judith Coffman; Lin, Yu-Feng

    2003-01-01

    A Silver Lake water budget was defined using both published hydrologic data and simulations using the calibrated model. Model simulations show that 1.08 cubic feet per second of ground water enters Silver Lake on the upgradient (primarily western) side and 0.08 cubic feet per second recharges to ground water on the downgradient (primarily eastern) side. Net precipitation (precipitation minus evaporation) on the lake is 0.04 cubic feet per second. Collectively, these water-budget terms provide a residual value of 1.04 cubic feet per second flow to Silver Creek at the north end of Silver Lake, which is a very good match to the range of measured flow (0.7 to 5.2 cubic feet per second). Ground-water recharge areas for Silver Lake are largely on the western side of the lake. The recharge area for the northern two-thirds of Silver Lake is west toward Big Cedar Lake. Assuming a porosity of 20 percent, model results indicate that the 50-year time-of-travel for recharge to Silver Lake does not extend to Big Cedar Lake. The recharge area for the southern one-third of Silver Lake is west toward Little Cedar Lake. Model results indicate that time of travel for recharge to Silver Lake from Little Cedar Lake is about 15 to 20 years. For travel times greater than 15 or 20 years, the ground-water recharge area for Little Cedar Lake and inflow from Big Cedar Lake also should be considered recharge affecting Silver Lake. Solute flux toward Silver Lake was calculated based on simulated ground-water flux and measured concentrations in the upgradient piezometers and observation wells.

  17. High frequency of silver resistance genes in invasive isolates of Enterobacter and Klebsiella species.

    PubMed

    Sütterlin, S; Dahlö, M; Tellgren-Roth, C; Schaal, W; Melhus, Å

    2017-07-01

    Silver-based products have been marketed as an alternative to antibiotics, and their consumption has increased. Bacteria may, however, develop resistance to silver. To study the presence of genes encoding silver resistance (silE, silP, silS) over time in three clinically important Enterobacteriaceae genera. Using polymerase chain reaction (PCR), 752 bloodstream isolates from the years 1990-2010 were investigated. Age, gender, and ward of patients were registered, and the susceptibility to antibiotics and silver nitrate was tested. Clonality and single nucleotide polymorphism were assessed with repetitive element sequence-based PCR, multi-locus sequence typing, and whole-genome sequencing. Genes encoding silver resistance were detected most frequently in Enterobacter spp. (48%), followed by Klebsiella spp. (41%) and Escherichia coli 4%. Phenotypical resistance to silver nitrate was found in Enterobacter (13%) and Klebsiella (3%) isolates. The lowest carriage rate of sil genes was observed in blood isolates from the neonatology ward (24%), and the highest in blood isolates from the oncology/haematology wards (66%). Presence of sil genes was observed in international high-risk clones. Sequences of the sil and pco clusters indicated that a single mutational event in the silS gene could have caused the phenotypic resistance. Despite a restricted consumption of silver-based products in Swedish health care, silver resistance genes are widely represented in clinical isolates of Enterobacter and Klebsiella species. To avoid further selection and spread of silver-resistant bacteria with a high potential for healthcare-associated infections, the use of silver-based products needs to be controlled and the silver resistance monitored. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  18. Ageing of plasma-mediated coatings with embedded silver nanoparticles on stainless steel: An XPS and ToF-SIMS investigation

    NASA Astrophysics Data System (ADS)

    Zanna, S.; Saulou, C.; Mercier-Bonin, M.; Despax, B.; Raynaud, P.; Seyeux, A.; Marcus, P.

    2010-09-01

    Nanocomposite thin films (˜170 nm), composed of silver nanoparticles enclosed in an organosilicon matrix, were deposited onto stainless steel, with the aim of preventing biofilm formation. The film deposition was carried out under cold plasma conditions, combining radiofrequency (RF) glow discharge fed with argon and hexamethyldisiloxane and simultaneous silver sputtering. XPS and ToF-SIMS were used to characterize Ag-organosilicon films in native form and after ageing in saline solution (NaCl 0.15 M), in order to further correlate their lifetime with their anti-fouling properties. Two coatings with significantly different silver contents (7.5% and 20.3%) were tested. Surface analysis confirmed the presence of metallic silver in the pristine coating and revealed significant modifications after immersion in the saline solution. Two different ageing mechanisms were observed, depending on the initial silver concentration in the film. For the sample exhibiting the low silver content (7.5%), the metal amount decreased at the surface in contact with the solution, due to the release of silver from the coating. As a result, after a 2-day exposure, silver nanoparticles located at the extreme surface were entirely released, whereas silver is still present in the inner part of the film. The coating thickness was not modified during ageing. In contrast, for the high silver content film (20.3%), the thickness decreased with immersion time, due to significant silver release and matrix erosion, assigned to a percolation-like effect. However, after 18 days of immersion, the delamination process stopped and a thin strongly bounded layer remained on the stainless steel surface.

  19. Ethylene Receptor 1 (ETR1) Is Sufficient and Has the Predominant Role in Mediating Inhibition of Ethylene Responses by Silver in Arabidopsis thaliana*

    PubMed Central

    McDaniel, Brittany K.; Binder, Brad M.

    2012-01-01

    Ethylene influences many processes in Arabidopsis thaliana through the action of five receptor isoforms. All five isoforms use copper as a cofactor for binding ethylene. Previous research showed that silver can substitute for copper as a cofactor for ethylene binding activity in the ETR1 ethylene receptor yet also inhibit ethylene responses in plants. End-point and rapid kinetic analyses of dark-grown seedling growth revealed that the effects of silver are mostly dependent upon ETR1, and ETR1 alone is sufficient for the effects of silver. Ethylene responses in etr1-6 etr2-3 ein4-4 triple mutants were not blocked by silver. Transformation of these triple mutants with cDNA for each receptor isoform under the promoter control of ETR1 revealed that the cETR1 transgene completely rescued responses to silver while the cETR2 transgene failed to rescue these responses. The other three isoforms partially rescued responses to silver. Ethylene binding assays on the binding domains of the five receptor isoforms expressed in yeast showed that silver supports ethylene binding to ETR1 and ERS1 but not the other isoforms. Thus, silver may have an effect on ethylene signaling outside of the ethylene binding pocket of the receptors. Ethylene binding to ETR1 with silver was ∼30% of binding with copper. However, alterations in the Kd for ethylene binding to ETR1 and the half-time of ethylene dissociation from ETR1 do not underlie this lower binding. Thus, it is likely that the lower ethylene binding activity of ETR1 with silver is due to fewer ethylene binding sites generated with silver versus copper. PMID:22692214

  20. Influence of Particle Size on Persistence and Clearance of Aerosolized Silver Nanoparticles in the Rat Lung

    PubMed Central

    Anderson, Donald S.; Patchin, Esther S.; Silva, Rona M.; Uyeminami, Dale L.; Sharmah, Arjun; Guo, Ting; Das, Gautom K.; Brown, Jared M.; Shannahan, Jonathan; Gordon, Terry; Chen, Lung Chi; Pinkerton, Kent E.; Van Winkle, Laura S.

    2015-01-01

    The growing use of silver nanoparticles (AgNPs) in consumer products raises concerns about potential health effects. This study investigated the persistence and clearance of 2 different size AgNPs (20 and 110 nm) delivered to rats by single nose-only aerosol exposures (6 h) of 7.2 and 5.4 mg/m3, respectively. Rat lung tissue was assessed for silver accumulations using inductively-coupled plasma mass spectrometry (ICP-MS), autometallography, and enhanced dark field microscopy. Involvement of tissue macrophages was assessed by scoring of silver staining in bronchoalveolar lavage fluid (BALF). Silver was abundant in most macrophages at 1 day post-exposure. The group exposed to 20 nm AgNP had the greatest number of silver positive BALF macrophages at 56 days post-exposure. While there was a significant decrease in the amount of silver in lung tissue at 56 days post-exposure compared with 1 day following exposure, at least 33% of the initial delivered dose was still present for both AgNPs. Regardless of particle size, silver was predominantly localized within the terminal bronchial/alveolar duct junction region of the lung associated with extracellular matrix and within epithelial cells. Inhalation of both 20 and 110 nm AgNPs resulted in a persistence of silver in the lung at 56 days post-exposure and local deposition as well as accumulation of silver at the terminal bronchiole alveolar duct junction. Further the smaller particles, 20 nm AgNP, produced a greater silver burden in BALF macrophages as well as greater persistence of silver positive macrophages at later timepoints (21 and 56 days). PMID:25577195

  1. Preparation and in vitro antimicrobial activity of silver-bearing degradable polymeric nanoparticles of polyphosphoester-block-poly(L-lactide).

    PubMed

    Lim, Young H; Tiemann, Kristin M; Heo, Gyu Seong; Wagers, Patrick O; Rezenom, Yohannes H; Zhang, Shiyi; Zhang, Fuwu; Youngs, Wiley J; Hunstad, David A; Wooley, Karen L

    2015-02-24

    The development of well-defined polymeric nanoparticles (NPs) as delivery carriers for antimicrobials targeting human infectious diseases requires rational design of the polymer template, an efficient synthetic approach, and fundamental understanding of the developed NPs, e.g., drug loading/release, particle stability, and other characteristics. Herein, we developed and evaluated the in vitro antimicrobial activity of silver-bearing, fully biodegradable and functional polymeric NPs. A series of degradable polymeric nanoparticles (dNPs), composed of phosphoester and L-lactide and designed specifically for silver loading into the hydrophilic shell and/or the hydrophobic core, were prepared as potential delivery carriers for three different types of silver-based antimicrobials-silver acetate or one of two silver carbene complexes (SCCs). Silver-loading capacities of the dNPs were not influenced by the hydrophilic block chain length, loading site (i.e., core or shell), or type of silver compound, but optimization of the silver feed ratio was crucial to maximize the silver loading capacity of dNPs, up to ca. 12% (w/w). The release kinetics of silver-bearing dNPs revealed 50% release at ca. 2.5-5.5 h depending on the type of silver compound. In addition, we undertook a comprehensive evaluation of the rates of hydrolytic or enzymatic degradability and performed structural characterization of the degradation products. Interestingly, packaging of the SCCs in the dNP-based delivery system improved minimum inhibitory concentrations up to 70%, compared with the SCCs alone, as measured in vitro against 10 contemporary epidemic strains of Staphylococcus aureus and eight uropathogenic strains of Escherichia coli. We conclude that these dNP-based delivery systems may be beneficial for direct epithelial treatment and/or prevention of ubiquitous bacterial infections, including those of the skin and urinary tract.

  2. Mosquito larvicidal properties of silver nanoparticles synthesized using Heliotropium indicum (Boraginaceae) against Aedes aegypti, Anopheles stephensi, and Culex quinquefasciatus (Diptera: Culicidae).

    PubMed

    Veerakumar, Kaliyan; Govindarajan, Marimuthu; Rajeswary, Mohan; Muthukumaran, Udaiyan

    2014-06-01

    Mosquitoes transmit dreadful diseases to human beings wherein biological control of these vectors using plant-derived molecules would be an alternative to reduce mosquito population. In the present study activity of aqueous leaf extract and silver nanoparticles (AgNPs) synthesized using Helitropium indicum plant leaves against late third instar larvae of Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus. The range of varying concentrations of synthesized AgNPs (8, 16, 24, 32, and 40 μg/mL) and aqueous leaf extract (30, 60, 90, 120, and 150 μg/mL) were tested against the larvae of Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus. The synthesized AgNPs from H. indicum were highly toxic than crude leaf aqueous extract in three important vector mosquito species. The results were recorded from UV-Vis spectrum, Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy analysis, transmission electron microscopy, and histogram. The synthesized AgNPs showed larvicidal effects after 24 h of exposure. Considerable mortality was evident after the treatment of H. indicum for all three important vector mosquitoes. The LC50 and LC90 values of H. indicum aqueous leaf extract appeared to be effective against A. stephensi (LC50, 68.73 μg/mL; LC90, 121.07 μg/mL) followed by A. aegypti (LC50, 72.72 μg/mL; LC90, 126.86 μg/mL) and C. quinquefasciatus (LC50, 78.74 μg/mL; LC90, 134.39 μg/mL). Synthesized AgNPs against the vector mosquitoes of A. stephensi, A. aegypti, and C. quinquefasciatus had the following LC50 and LC90 values: A. stephensi had LC50 and LC90 values of 18.40 and 32.45 μg/mL, A. aegypti had LC50 and LC90 values of 20.10 and 35.97 μg/mL, and C. quinquefasciatus had LC50 and LC90 values of 21.84 and 38.10 μg/mL. No mortality was observed in the control. These results suggest that the leaf aqueous extracts of H. indicum and green synthesis of silver nanoparticles have the potential to be used as an ideal ecofriendly approach for the control of A. stephensi, A. aegypti, and C. quinquefasciatus. This is the first report on the mosquito larvicidal activity of the plant extracts and synthesized nanoparticles.

  3. US Army, Air Force, and Navy RPMA Consolidation in Panama. A Cost- Benefit Analysis. Volume I

    DTIC Science & Technology

    1979-09-01

    4 M4 4 -~ hi 𔃺~~, 8 wu * ’ * Na A4V41 0d 00* ~~41C4 C6 - .- 1 ~fl .(’ 4 r4 - EJ ~ :f4 400 re V- 4 Id a 3960 b(3) The fourth column... 4 . 4 0- 4 :64 0 4 V4 %- V4 u -F.e*,* V4 g~I c c 0 a. c O 41~ V 04 S 8 J *h.0 >. 44U . U QS U) 4 U 1 ~- 4 0 0 va b *v 0 -.- - 4 .- 4 Wu" A 4 IW ra...Is A 8 1 I~~~~~, 5-- 4 -Ž’ .v*C ~ * ~ ~ ~ ~ ~ ~ "o ’ I

  4. National Dam Safety Program. Main Mill Dam (Inventory Number N.Y. 262), Lake Champlain Basin, Clinton County, New York. Phase I Inspection Report,

    DTIC Science & Technology

    1981-09-21

    00 a0l 2 i K~~~~W 0 0 11 - 00 0 0: 3000. 0 000 #4IL .4 4 00. II O (0 4 2 0 4 O0NI. * 1.414 6 1 * 01% w 0-3 0 ft a KO na a’ aVNi *~~~~- 0- 4 1000 .00...S USO S ft# 6-31@@~1~eN~iS~l0540-31 140 31 srn 0500 4- U 0-C S U S E S C J C #If skO - S U S 4 0 Ow .U -, sa s4* a. 04 , m .4Va aP.9aI 0. 00ee s es

  5. Marine Environmental Planning Guide for the Hampton Roads/Norfolk Operating Area.

    DTIC Science & Technology

    1974-05-01

    t~J ’SWo 10 𔃻 ..... 43303UA~ A** 00 * 1 31.9 -~f -- f., 41 Aef"G .G 3 3 -1.9’ OC ’amV. -.9v ... G "* Cft 𔃻 IAMv PPO.$ ENLARGEMENT E o Iy PERMISSION...ut DlAl’ aml I indane on qlycolyt ic andi ,J I L1 ’ 11 n<K~~ Ionic (!i~~sot thec 4pahi,; , Me rcxvn aria mercenavr-ia, 5- ,7p., Uiuted Nit tons PuxA...North Cairol imi Dtpt . ot (Con.;etVat ion .iml DlX’,󈧏Tnt , Divi!;ion oit Cimmrcixil ’~~~~I~ by .B.li;t IuX inll sst~b illa5𔃿 i Strulctlure aml

  6. Department of Defense Prime Contracts over $25,000 for Services. Fiscal Year 1992. Part 2 (K010 Analysis & Technology Inc-T099 Xerox Corp)

    DTIC Science & Technology

    1993-01-01

    0000 (000 1. 0 z z acca at "rto "r ;,- at or a t U tut t C t at a aU. > or t-CC C C C C C C 10a at at c at at at at at @ 0 C 0 0~~~~~~~~ >at >t 4 1 t...6 . F . . 11 . . - L I- & UI f6 )V A c ) 0 ( A V ) ( A 0 t A ( A L A ( I m - r U)0 0 0 𔃺 a 60 t C a I u I 1’ : 666ý q 0 - r4 - 4 - 4 -4 r4 - - 4 ý

  7. Potentiometric titration of thiols, cationic surfactants and halides using a solid-state silver-silver sulphide electrode.

    PubMed

    Pinzauti, S; Papeschi, G; La Porta, E

    1983-01-01

    A rugged, low resistance silver-silver sulphide solid-state electrode for determining pharmaceuticals as authentic samples or in dosage forms by potentiometric titration is described. Sodium tetraphenylborate, mercury(II) acetate and silver nitrate (0.01) M were employed as titrants in the analysis of cationic surfactants (cetylpyridinium chloride, benzethonium chloride, benzalkonium chloride and chlorhexidine salts), antithyroid drugs (methimazole and propylthiouracil) or sodium halides respectively.

  8. Cytotoxic effects of nanosilver are highly dependent on the chloride concentration and the presence of organic compounds in the cell culture media.

    PubMed

    Kaiser, Jean-Pierre; Roesslein, Matthias; Diener, Liliane; Wichser, Adrian; Nowack, Bernd; Wick, Peter

    2017-01-06

    Nanosilver shows great promise for use in industrial, consumer or medical products because of its antimicrobial properties. However, the underlying mechanisms of the effects of silver nanoparticles on human cells are still controversial. Therefore, in the present study the influence of the chloride concentration and different serum content of culture media on the cytotoxic effects of nanosilver was systematically evaluated. Our results show that nanosilver toxicity was strongly affected by the composition of the culture media. The chloride concentration, as well as the carbon content affected the silver agglomeration and the complex formation. But also the dissolution of nanosilver and the availability of free silver ions (Ag + ) were severely affected by the compositions of the culture media. Cells, only exposed to silver particles in suspension and dissolved silver complexes, did not show any effects under all conditions. Nanosilver agglomerates and silver complexes were not very soluble. Thus, cells growing on the bottom of the culture dishes were exposed to sedimented nanosilver agglomerates and precipitated silver complexes. Locally, the concentration of silver on the cell surface was very high, much higher compared the silver concentration in the bulk solution. The cytotoxic effects of nanosilver are therefore a combination of precipitated silver complexes and organic silver compounds rather than free silver ions. Silver coatings are used in health care products due to their bacteriostatic or antibacterial properties. The assessment of the toxicity of a certain compound is mostly done using in vitro assays. Therefore, cytotoxicity studies of nanosilver using human cell cultures have to be undertaken under well controlled and understood cultivations conditions in order to improve the compatibility of different studies. Especially when eukaryotic versus prokaryotic systems are compared for the evaluation of the use of nanosilver as antibacterial coatings for implants in order to prevent bacterial colonization.

  9. The effect of nano-silver packaging in increasing the shelf life of nuts: An in vitro model

    PubMed Central

    Tavakoli, Hamidreza; Rastegar, Hossein; Taherian, Mahdi; Samadi, Mohammad; Rostami, Hossein

    2017-01-01

    Nano packaging is currently one of the most important topics in food packaging technologies. The aim of the application of this technology in food packaging is increasing shelf life of foods by preventing internal and external corruption and microbial contaminations. Use of silver nanoparticles in food packaging has recently attracted much attention. The aim of this study was to investigate the effect of nano-silver packaging in increasing the shelf life packages of nuts in an In vitro model. In this experimental study, the effects of different nano-silver concentrations (0, 1, 2 and 3 percent) on biological and chemical properties of 432 samples of nuts including walnuts, hazelnuts, almonds and pistachios were evaluated during 0, 3, 6, 9, 12, 15, 18, 21 and 24 months. In most samples, different concentrations of nano-silver (1, 2 and 3 %) significantly reduced total microbial count, mold and coliform counts compared to control group and the 3% nano-silver concentration was more effective than other concentrations (P<0.05). Moreover, using this packaging yielded an antioxidant effect especially when 2% and 3% nano-silver concentrations were used. Nano-silver also prevented growth of mold and so prevented aflatoxin production in all treatment groups. Results of chemical and biological tests showed that the silver nanoparticles had a significant effect on increasing the shelf life of nuts. The highest shelf life belonged to pistachios, almonds, hazelnuts and walnuts with 20, 19, 18 and 18 months, respectively. The shelf life was associated with amount of silver nanoparticles. The highest antimicrobial activity was observed when 3% nano-silver concentration was used in pistachios. The shelf life of control groups in similar storage conditions were calculated for an average of 13 months. In conclusion, the results of this study demonstrate the efficacy of nano-silver packing in increasing shelf life of nuts. Hence, use of nano-silver packaging in food industry, especially in food packaging is recommended. PMID:29564232

  10. The effect of nano-silver packaging in increasing the shelf life of nuts: An in vitro model.

    PubMed

    Tavakoli, Hamidreza; Rastegar, Hossein; Taherian, Mahdi; Samadi, Mohammad; Rostami, Hossein

    2017-10-20

    Nano packaging is currently one of the most important topics in food packaging technologies. The aim of the application of this technology in food packaging is increasing shelf life of foods by preventing internal and external corruption and microbial contaminations. Use of silver nanoparticles in food packaging has recently attracted much attention. The aim of this study was to investigate the effect of nano-silver packaging in increasing the shelf life packages of nuts in an In vitro model. In this experimental study, the effects of different nano-silver concentrations (0, 1, 2 and 3 percent) on biological and chemical properties of 432 samples of nuts including walnuts, hazelnuts, almonds and pistachios were evaluated during 0, 3, 6, 9, 12, 15, 18, 21 and 24 months. In most samples, different concentrations of nano-silver (1, 2 and 3 %) significantly reduced total microbial count, mold and coliform counts compared to control group and the 3% nano-silver concentration was more effective than other concentrations (P<0.05). Moreover, using this packaging yielded an antioxidant effect especially when 2% and 3% nano-silver concentrations were used. Nano-silver also prevented growth of mold and so prevented aflatoxin production in all treatment groups. Results of chemical and biological tests showed that the silver nanoparticles had a significant effect on increasing the shelf life of nuts. The highest shelf life belonged to pistachios, almonds, hazelnuts and walnuts with 20, 19, 18 and 18 months, respectively. The shelf life was associated with amount of silver nanoparticles. The highest antimicrobial activity was observed when 3% nano-silver concentration was used in pistachios. The shelf life of control groups in similar storage conditions were calculated for an average of 13 months. In conclusion, the results of this study demonstrate the efficacy of nano-silver packing in increasing shelf life of nuts. Hence, use of nano-silver packaging in food industry, especially in food packaging is recommended.

  11. Toxicogenomic responses of nanotoxicity in Daphnia magna exposed to silver nitrate and coated silver nanoparticles

    EPA Science Inventory

    Applications for silver nanomaterials in consumer products are rapidly expanding, creating an urgent need for toxicological examination of the exposure potential and ecological effects of silver nanoparticles (AgNPs). The integration of genomic techniques into environmental toxic...

  12. Green synthesis of silver nanoparticles using a Melissa officinalis leaf extract with antibacterial properties

    NASA Astrophysics Data System (ADS)

    de Jesús Ruíz-Baltazar, Álvaro; Reyes-López, Simón Yobbany; Larrañaga, Daniel; Estévez, Miriam; Pérez, Ramiro

    The exceptional properties of the silver nanoparticles offer several applications in the biomedicine field. The development of antibiotics which are clinically useful against bacteria and drug resistant microorganisms, it is one of the main approaches of silver nanoparticles. However, it is necessary to develop environmentally friendly methods for their synthesis. In this sense, the main objective of this work is focused on to propose a simplified and efficient green synthesis of silver nanoparticles with proven antibacterial properties. The green synthesis route is based on the use of the Melissa officinalis as reducing agent of the silver ions in aqueous solution at room temperature. Complementary, the antibacterial activity of the silver nanoparticles against Staphylococcus aureus and Escherichia coli was confirmed. The silver nanoparticles obtained were characterized by transmission electron microscopy, X-ray diffraction, UV-vis, Raman and FT-IR spectroscopy. The observed results suggested that using Melissa officinalis, it is possible to performed silver nanoparticles with controlled characteristics and with significant inhibitory activity against the Staphylococcus aureus and Escherichia coli.

  13. Spectroscopic study of surface enhanced Raman scattering of caffeine on borohydride-reduced silver colloids

    NASA Astrophysics Data System (ADS)

    Chen, Xiaomin; Gu, Huaimin; Shen, Gaoshan; Dong, Xiao; Kang, Jian

    2010-06-01

    The surface enhanced Raman scattering (SERS) of caffeine on borohydride-reduced silver colloids system under different aqueous solution environment has been studied in this paper. The relative intensity of SERS of caffeine significantly varies with different concentrations of sodium chloride and silver particles. However, at too high or too low concentration of sodium chloride and silver particle, the enhancement of SERS spectra is not evident. The SERS spectra of caffeine suggest that the contribution of the charge transfer mechanism to SERS may be dominant. The chloride ions can significantly enhance the efficiency of SERS, while the enhancement is selective, as the efficiency in charge transfer enhancement is higher than in electromagnetic enhancement. Therefore, it can be concluded that the active site of chloride ion locates on the bond between the caffeine and the silver surface. In addition, the SERS spectra of caffeine on borohydride-reduced and citrate-reduced silver colloids are different, which may be due to different states caffeine adsorbed on silver surface under different silver colloids.

  14. Enhancement of the stability of silver nanoparticles synthesized using aqueous extract of Diospyros discolor Willd. leaves using polyvinyl alcohol

    NASA Astrophysics Data System (ADS)

    Ardani, H. K.; Imawan, C.; Handayani, W.; Djuhana, D.; Harmoko, A.; Fauzia, V.

    2017-04-01

    Biosynthesis of silver nanoparticles is recently attracting considerable attention because of it reduces the environmental impact and already used in numerous applications. However, the disadvantages such as easy aggregation and instability properties, prevent its’ application. In this papers, biosynthesis of silver nanoparticles using aqueous extract of Diospyros discolor Willd. leaves have been prepared. The effect of biosynthesis variables, like ratio of reactants and reduction time on the particle size distribution, stability, and morphology of the silver nanoparticles were investigated. The resulted silver nanoparticles were characterized using UV spectroscopy, Transmission Electron Microscopy, and Particles Size Analyzer. Polyvinyl alcohol (PVA) was used to enhance the stability of the silver nanoparticles. Silver nanoparticles modification with 1% PVA concentration has produced a better characteristic of particle size distribution compared to the original silver nanoparticles, from highly polydisperse into moderately disperse. The results of the Zetta potential measurement also confirmed the increase stability of cluster distribution in the colloidal Ag/PVA compared to the original Ag.

  15. Oral toxicity of silver ions, silver nanoparticles and colloidal silver--a review.

    PubMed

    Hadrup, Niels; Lam, Henrik R

    2014-02-01

    Orally administered silver has been described to be absorbed in a range of 0.4-18% in mammals with a human value of 18%. Based on findings in animals, silver seems to be distributed to all of the organs investigated, with the highest levels being observed in the intestine and stomach. In the skin, silver induces a blue-grey discoloration termed argyria. Excretion occurs via the bile and urine. The following dose-dependent animal toxicity findings have been reported: death, weight loss, hypoactivity, altered neurotransmitter levels, altered liver enzymes, altered blood values, enlarged hearts and immunological effects. Substantial evidence exists suggesting that the effects induced by particulate silver are mediated via silver ions that are released from the particle surface. With the current data regarding toxicity and average human dietary exposure, a Margin of Safety calculation indicates at least a factor of five before a level of concern to the general population is reached. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Electroless silver coating of rod-like glass particles.

    PubMed

    Moon, Jee Hyun; Kim, Kyung Hwan; Choi, Hyung Wook; Lee, Sang Wha; Park, Sang Joon

    2008-09-01

    An electroless silver coating of rod-like glass particles was performed and silver glass composite powders were prepared to impart electrical conductivity to these non-conducting glass particles. The low density Ag-coated glass particles may be utilized for manufacturing conducting inorganic materials for electromagnetic interference (EMI) shielding applications and the techniques for controlling the uniform thickness of silver coating can be employed in preparation of biosensor materials. For the surface pretreatment, Sn sensitization was performed and the coating powders were characterized by scanning electron microscopy (SEM), focused ion beam microscopy (FIB), and atomic force microscopy (AFM) along with the surface resistant measurements. In particular, the use of FIB technique for determining directly the Ag-coating thickness was very effective on obtaining the optimum conditions for coating. The surface sensitization and initial silver loading for electroless silver coating could be found and the uniform and smooth silver-coated layer with thickness of 46 nm was prepared at 2 mol/l of Sn and 20% silver loading.

  17. A study of silver species on silver-exchanged ETS-10 and mordenite by XRD, SEM and solid-state 109Ag, 29Si and 27AI NMR spectroscopy.

    PubMed

    Liu, Yan; Chen, Fu; Wasylishen, Roderick E; Xu, Zhenghe; Sawada, James; Kuznicki, Steven M

    2012-08-01

    Silver zeolites, especially Ag-ETS-10 and Ag-mordenite, actively bind xenon and iodine, two prime contaminants common to nuclear accidents. The evolution of silver species on silver exchanged ETS-10 (Ag/ETS-10) and mordenite (Ag/Mor) has been investigated by exposing the materials to a series of activation conditions in Ar, air and H2. The samples were characterized by XRD, SEM and solid-state 109Ag, 29Si and 27AI MAS NMR. The silver reduction and structural evolution have been illustrated by those techniques. The effectiveness of one sample of each type of sieve was tested for its ability to trap mercury from a gas stream. However, the results from this study demonstrate that the adsorption characteristics of silver-loaded sieves cannot necessarily be predicted using a full complement of structural characterization techniques, which highlights the importance of understanding the formation and nature of silver species on molecular sieves.

  18. Biosynthesis of silver nanoparticles using lemon leaves extract and its application for antimicrobial finish on fabric

    NASA Astrophysics Data System (ADS)

    Vankar, Padma S.; Shukla, Dhara

    2012-06-01

    Preparation of silver nanoparticles have been carried out using aqueous extract of lemon leaves ( Citrus limon) which acts as reducing agent and encapsulating cage for the silver nanoparticles. These silver nanoparticles have been used for durable textile finish on cotton and silk fabrics. Remarkable antifungal activity has been observed in the treated fabrics. The antimicrobial activity of silver nanoparticles derived from lemon leaves showed enhancement in activity due to synergistic effect of silver and essential oil components of lemon leaves. The present investigation shows the extracellular synthesis of highly stable silver nanoparticles by biotransformation using the extract of lemon leaves by controlled reduction of the Ag+ ion to Ag0. Further the silver nanoparticles were used for antifungal treatment of fabrics which was tested by antifungal activity assessment of textile material by Agar diffusion method against Fusarium oxysporum and Alternaria brassicicola. Formation of the metallic nanoparticles was established by FT-IR, UV-Visible spectroscopy, transmission electron microscopy, scanning electron microscopy, atomic force microscopy.

  19. Electrodeposition as an alternate method for preparation of environmental samples for iodide by AMS

    DOE PAGES

    Adamic, M. L.; Lister, T. E.; Dufek, E. J.; ...

    2015-03-25

    This paper presents an evaluation of an alternate method for preparing environmental samples for 129I analysis by accelerator mass spectrometry (AMS) at Idaho National Laboratory. The optimal sample preparation method is characterized by ease of preparation, capability of processing very small quantities of iodide, and ease of loading into a cathode. Electrodeposition of iodide on a silver wire was evaluated using these criteria. This study indicates that the electrochemically-formed silver iodide deposits produce ion currents similar to those from precipitated silver iodide for the same sample mass. Furthermore, precipitated silver iodide samples are usually mixed with niobium or silver powdermore » prior to loading in a cathode. Using electrodeposition, the silver is already mixed with the sample and can simply be picked up with tweezers, placed in the sample die, and pressed into a cathode. The major advantage of this method is that the silver wire/electrodeposited silver iodide is much easier to load into a cathode.« less

  20. Ultra-low temperature curable nano-silver conductive adhesive for piezoelectric composite material

    NASA Astrophysics Data System (ADS)

    Yan, Chao; Liao, Qingwei; Zhou, Xingli; Wang, Likun; Zhong, Chao; Zhang, Di

    2018-01-01

    Limited by the low thermal resistance of composite material, ultra-low temperature curable conductive silver adhesive with curing temperature less than 100 °C needed urgently for the surface conduction treatment of piezoelectric composite material. An ultra-low temperature curable nano-silver conductive adhesive with high adhesion strength for the applications of piezoelectric composite material was investigated. The crystal structure of cured adhesive, SEM/EDS analysis, thermal analysis, adhesive properties and conductive properties of different content of nano-silver filler or micron-silver doping samples were studied. The results show that with 60 wt.% nano-silver filler the ultra-low temperature curable conductive silver adhesive had the relatively good conductivity as volume resistivity of 2.37 × 10-4 Ω cm, and good adhesion strength of 5.13 MPa. Minor micron-doping (below 15 wt.%) could improve conductivity, but would decrease other properties. The ultra-low temperature curable nano-silver conductive adhesive could successfully applied to piezoelectric composite material.

  1. Induction of lesions of selenium-vitamin E deficiency in pigs fed silver

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

    Van Vleet, J.F.

    1976-12-01

    Four weanling swine fed for 4 weeks a commercial ration adequate in selenium and vitamin E, but supplemented with 0.5% silver acetate, developed lesions typical of selenium-vitamin E deficiency. Clinically, the pigs fed this high level of silver had anorexia, diarrhea, and growth depression; 3 of 4 pigs died. At necropsy, hepatic lesions of hepatosis dietetica were present in 4 of 4 silver-fed pigs, and 1 of 4 pigs had cardiac and skeletal muscle lesions characteristic of selenium-vitamin E deficiency. Development of lesions and mortality was prevented in 2 pigs fed the silver diet supplemented with ..cap alpha..-tocopherol (100 IU/kgmore » of diet), but not in 2 pigs fed the ratio supplemented with selenium as selenite (1 ppm). Four pigs fed a lower dose level of silver (0.2% silver acetate) for 6 weeks failed to develop clinical or pathologic features of selenium-vitamin E deficiency. However, hepatic selenium content was significantly increased in pigs fed the silver-supplemented ration.« less

  2. Laser-Direct Writing of Silver Metal Electrodes on Transparent Flexible Substrates with High-Bonding Strength.

    PubMed

    Zhou, Weiping; Bai, Shi; Ma, Ying; Ma, Delong; Hou, Tingxiu; Shi, Xiaomin; Hu, Anming

    2016-09-21

    We demonstrate a novel approach to rapidly fabricate conductive silver electrodes on transparent flexible substrates with high-bonding strength by laser-direct writing. A new type of silver ink composed of silver nitrate, sodium citrate, and polyvinylpyrrolidone (PVP) was prepared in this work. The role of PVP was elucidated for improving the quality of silver electrodes. Silver nanoparticles and sintered microstructures were simultaneously synthesized and patterned on a substrate using a focused 405 nm continuous wave laser. The writing was completed through the transparent flexible substrate with a programmed 2D scanning sample stage. Silver electrodes fabricated by this approach exhibit a remarkable bonding strength, which can withstand an adhesive tape test at least 50 times. After a 1500 time bending test, the resistance only increased 5.2%. With laser-induced in-situ synthesis, sintering, and simultaneous patterning of silver nanoparticles, this technology is promising for the facile fabrication of conducting electronic devices on flexible substrates.

  3. Recovery of Silver and Gold from Copper Anode Slimes

    NASA Astrophysics Data System (ADS)

    Chen, Ailiang; Peng, Zhiwei; Hwang, Jiann-Yang; Ma, Yutian; Liu, Xuheng; Chen, Xingyu

    2015-02-01

    Copper anode slimes, produced from copper electrolytic refining, are important industrial by-products containing several valuable metals, particularly silver and gold. This article provides a comprehensive overview of the development of the extraction processes for recovering silver and gold from conventional copper anode slimes. Existing processes, namely pyrometallurgical processes, hydrometallurgical processes, and hybrid processes involving the combination of pyrometallurgical and hydrometallurgical technologies, are discussed based in part on a review of the form and characteristics of silver and gold in copper anode slimes. The recovery of silver and gold in pyrometallurgical processes is influenced in part by the slag and matte/metal chemistry and related characteristics, whereas the extraction of these metals in hydrometallurgical processes depends on the leaching reagents used to break the structure of the silver- and gold-bearing phases, such as selenides. By taking advantage of both pyrometallurgical and hydrometallurgical techniques, high extraction yields of silver and gold can be obtained using such combined approaches that appear promising for efficient extraction of silver and gold from copper anode slimes.

  4. Synthesis, characterization and antimicrobial activity of dextran stabilized silver nanoparticles in aqueous medium.

    PubMed

    Bankura, K P; Maity, D; Mollick, M M R; Mondal, D; Bhowmick, B; Bain, M K; Chakraborty, A; Sarkar, J; Acharya, K; Chattopadhyay, D

    2012-08-01

    A simple one-step rapid synthetic route is described for the preparation of silver nanoparticles by reduction of silver nitrate (AgNO3) using aqueous dextran solution which acts as both reducing and capping agent. The formation of silver nanoparticles is assured by characterization with UV-vis spectroscopy, atomic force microscopy (AFM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The absorbance of the silver nanoparticles is observed at 423 nm. The AFM image clearly shows the surface morphology of the well-dispersed silver nanoparticles with size range of 10-60 nm. TEM images show that the nanoparticles are spherical in shape with ∼5-10 nm dimensions. The crystallinity of Ag nanoparticles is assured by XRD analysis. The antimicrobial activity of as synthesized silver nanoparticles is tested against the bacteria, Bacillus subtilis, Bacillus cereus, Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. The bacterial growth is inhibited by gradual reduction of the concentration of the silver nanoparticles. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Radiation Effects on the Electrical Properties of MOS Device Materials.

    DTIC Science & Technology

    1978-02-01

    3 Under Contract e ~i8 DAAG39~~ C.0O88 tJTtj~ J b This work _ sponsored by di. Ds~nse Nuclear Aisocy undur Nuclear ~ ffiupons Effucta flussarch...numb •r) Si02, MOS , CMOS Vacuum Ultraviolet Radiation Radiation Hardness Interfac e States Capture Cross Sections 2 ’ ~~’*~~ TRACT (Continu e on...When 0 t e Entered ) Results show that unannealed dry oxides have the lowest interface— state density after irrad iation, making them more desirable

  6. Marginal Integrity of Glass Ionomer and All Ceramic Restorations

    DTIC Science & Technology

    2015-06-01

    submitted to the Faculty of the Comprehensive Dentistry Graduate Program Naval Postgraduate Dental School Uniformed Services University of the...Department ~~’JJ\\fvAJ\\,nM~ . ctfulinaro, Joseph, D.D.S, M.S. CAPT, DC, USN Program Director, Comprehensive Dentistry Depa11ment S:tX~ Kooistra...Scott, D.D.S CAPT, DC, USN Operati~~:ellti !~~ Departm:L-- Huber, ayson, D.D.S., M.S. LCDR, DC, USN Comprehensive Dentistry Department Arena, arc

  7. Distributed Heterogeneous Simulation of a Hybrid-Electric Vehicle

    DTIC Science & Technology

    2006-03-29

    voltage dc bus via a fully controlled three-phase bridge converter. Also connc·:[uJ iu tilL UUS are the Lithium - ion battery bank, the ultra-capacitor...s~b~;~~~~·3 .... ! Lithium - Ion Battery Storage I _ .. ~:; Low-voltage Bus i I I] j i DC~ Converter ! -~~- ti~! 1 I --Ii! Battery i...devices in the propulsion system include the lithium - ion battery bank and the ultra-capacitor. Based on the range of the vehicle in the stealth model

  8. LD Typing for Bone Marrow Transplantation.

    DTIC Science & Technology

    1977-06-15

    LD ( HLA —D) locus is the least understood. Separate Navy contracts deal with development of knowledge regarding the specific antigens present at this...locus. This contract is directed to the problem of collecting homozygous typing cells which can be used for P . ,At ~i1&~ L!~Y ~~~~ •i~~•~ (LD ( HLA —D...therefore decided to examine this group with preliminary testing to see whether they could yield the type ef cells necessary for HLA —D typing. Because

  9. Transportation Workload Forecasting (TWF) Study.

    DTIC Science & Technology

    1984-01-01

    inflation factors, changes in troop strengths; opening , closing, or consolidation of facilities; and changes in mode of transportation. (4) The Military...tons Initial attempts to read the data with a univariate statistics program failed, due to the existence of nonnumeric entries in data fields . Records...W M=wn.99,i.i.Pm.i-,9Nd.~ C;f* ne hJN lfr csN ewc S.-,n melt rlfMOMf7 . £9 V oocacooofll.O N trtoati9e ieonhnfbo£0 * **. .~ ~~~ ~~~~ n

  10. Phosphorobacterin and Its Effectiveness,

    DTIC Science & Technology

    1986-01-30

    Spring wheat. (10). Barley . (11). 12)• Vine mesquite. (13). Maize (grain). (14). Potatoes. (15). Average/mean addition on all cultures. Page 67. In...34. * (6). Spring wheat. (7). Vine mesquite. (8). Winter wheat. (9). I [I " Barley . ~~~~~ ~~ ~ ~ .(1) Oas (11) Bukha.(2. oaos 1) flpoa, m . ua 22 3,0 1.0 2...effect was somewhat abovE. But if we discard not the instilling confidence the data about the barley , then an average/mean increase in the crop of

  11. The Impaction Force of Airborne Particles on Spheres and Cylinders

    DTIC Science & Technology

    1978-09-01

    oa8 c- 0 tw ni ni neIt ,5 "tU 0 fc 0N . -t r. "II l f 4 4 0 4 f f 4 ý l I " I w ~ C 001 00 0000 000000 40001 00 CoO eeoc swum~ ~~~~~~~ coo 0000 Cj UC L...number. The three gritip% .ru defined in Appendix ’M’of the DRB Security Regulations . 11) "Oualified requesters may obtain copies of this document from

  12. Transgenic Analysis of the Role of FKBP12.6 in Cardiac Function and Intracellular Calcium Release

    PubMed Central

    Liu, Ying; Chen, Hanying; Ji, Guangju; Li, Baiyan; Mohler, Peter J.; Zhu, Zhiming; Yong, Weidong; Chen, Zhuang; Xu, Xuehong

    2011-01-01

    Abstract FK506 binding protein12.6 (FKBP12.6) binds to the Ca2+ release channel ryanodine receptor (RyR2) in cardiomyocytes and stabilizes RyR2 to prevent premature sarcoplasmic reticulum Ca2+ release. Previously, two different mouse strains deficient in FKBP12.6 were reported to have different abnormal cardiac phenotypes. The first mutant strain displayed sex-dependent cardiac hypertrophy, while the second displayed exercise-induced cardiac arrhythmia and sudden death. In this study, we tested whether FKBP12.6-deficient mice that display hypertrophic hearts can develop exercise-induced cardiac sudden death and whether the hypertrophic heart is a direct consequence of abnormal calcium handling in mutant cardiomyocytes. Our data show that FKBP12.6-deficient mice with cardiac hypertrophy do not display exercise-induced arrhythmia and/or sudden cardiac death. To investigate the role of FKBP12.6 overexpression for cardiac function and cardiomyocyte calcium release, we generated a transgenic mouse line with cardiac specific overexpression of FKBP12.6 using α-myosin heavy chain (αMHC) promoter. MHC-FKBP12.6 mice displayed normal cardiac development and function. We demonstrated that MHC-FKBP12.6 mice are able to rescue abnormal cardiac hypertrophy and abnormal calcium release in FKBP12.6-deficient mice. PMID:22087651

  13. 10 CFR 1.26 - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false [Reserved] 1.26 Section 1.26 Energy NUCLEAR REGULATORY COMMISSION STATEMENT OF ORGANIZATION AND GENERAL INFORMATION Headquarters Commission Staff § 1.26 [Reserved] ...

  14. FKBP12.6 protects heart from AngII-induced hypertrophy through inhibiting Ca2+ /calmodulin-mediated signalling pathways in vivo and in vitro.

    PubMed

    Xiao, Yun-Fei; Zeng, Zhi-Xiong; Guan, Xiao-Hui; Wang, Ling-Fang; Wang, Chan-Juan; Shi, Huidong; Shou, Weinian; Deng, Ke-Yu; Xin, Hong-Bo

    2018-04-22

    We previously observed that disruption of FK506-binding protein 12.6 (FKBP12.6) gene resulted in cardiac hypertrophy in male mice. Studies showed that overexpression of FKBP12.6 attenuated thoracic aortic constriction (TAC)-induced cardiac hypertrophy in mice, whereas the adenovirus-mediated overexpression of FKBP12.6 induced hypertrophy and apoptosis in cultured neonatal cardiomyocytes, indicating that the role of FKBP12.6 in cardiac hypertrophy is still controversial. In this study, we aimed to investigate the roles and mechanisms of FKBP12.6 in angiotensin II (AngII)-induced cardiac hypertrophy using various transgenic mouse models in vivo and in vitro. FKBP12.6 knockout (FKBP12.6 -/- ) mice and cardiac-specific FKBP12.6 overexpressing (FKBP12.6 TG) mice were infused with AngII (1500 ng/kg/min) for 14 days subcutaneously by implantation of an osmotic mini-pump. The results showed that FKBP12.6 deficiency aggravated AngII-induced cardiac hypertrophy, while cardiac-specific overexpression of FKBP12.6 prevented hearts from the hypertrophic response to AngII stimulation in mice. Consistent with the results in vivo, overexpression of FKBP12.6 in H9c2 cells significantly repressed the AngII-induced cardiomyocyte hypertrophy, seen as reductions in the cell sizes and the expressions of hypertrophic genes. Furthermore, we demonstrated that the protection of FKBP12.6 on AngII-induced cardiac hypertrophy was involved in reducing the concentration of intracellular Ca 2+ ([Ca 2+ ]i), in which the protein significantly inhibited the key Ca 2+ /calmodulin-dependent signalling pathways such as calcineurin/cardiac form of nuclear factor of activated T cells 4 (NFATc4), calmodulin kinaseII (CaMKII)/MEF-2, AKT/Glycogen synthase kinase 3β (GSK3β)/NFATc4 and AKT/mTOR signalling pathways. Our study demonstrated that FKBP12.6 protects heart from AngII-induced cardiac hypertrophy through inhibiting Ca 2+ /calmodulin-mediated signalling pathways. © 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  15. Synthesis and characterization of silver nanoparticles using Caesalpinia pulcherrima flower extract and assessment of their in vitro antimicrobial, antioxidant, cytotoxic, and genotoxic activities.

    PubMed

    Moteriya, Pooja; Chanda, Sumitra

    2017-12-01

    Caesalpinia pulcherrima flower extract mediated synthesis of silver nanoparticles was attempted in the present work including optimization of some procedure parameters. Characterization of synthesized silver nanoparticles was done by various spectral analyses. The size of synthesized silver nanoparticles was 12 nm and they were spherical in shape. The green synthesized silver nanoparticles were further evaluated for antimicrobial, antioxidant, cytotoxic, and genotoxic activities; they showed good antimicrobial, antioxidant, and cytotoxic effects. Genotoxic study revealed non-toxic nature at lower concentration. Overall results suggest that the synthesized silver nanoparticles have pronounced applicability in pharmaceutical and biomedical field.

  16. Extraction of three-dimensional silver nanostructures with supercritical fluid

    NASA Astrophysics Data System (ADS)

    Taguchi, Natsuo; Takeyasu, Nobuyuki; Kawata, Satoshi

    2018-02-01

    In a previous report, a self-growing approach was proposed for fabricating complex silver nanostructures, where silver dendrites were grown at silver nanoseeds in silver ion solution owing to plasmonic heating with ultraviolet light. Structures were deformed or destroyed when they were extracted with acetone and dried in air. In this Letter, we discuss the use of supercritical carbon dioxide fluid for the nondestructive extraction of nanostructures. We show the experimental results and discuss the laser power dependence of resultant structures. Another experiment was performed for nanostructure growth inside an agarose gel as a matrix. Silver nanostructures were immobilized without damage in an agarose skeleton network.

  17. Synthesis of silver nanoparticles from Melia dubia leaf extract and their in vitro anticancer activity

    NASA Astrophysics Data System (ADS)

    Kathiravan, V.; Ravi, S.; Ashokkumar, S.

    2014-09-01

    Silver nanoparticles have a significant role in the pharmaceutical science. Especially, silver nanoparticles synthesized by the plant extracts lead a significant role in biological activities such as antimicrobial, antioxidant and anticancer. Keeping this in mind, the present work investigation has been taken up with the synthesized silver nanoparticles using the plant extract of Melia dubia and it characterizes by using UV-visible, XRD and SEM-EDS. The effect of the silver nanoparticles on human breast cancer (KB) cell line has been tested. Silver nanoparticles showed remarkable cytotoxicity activity against KB cell line with evidence of high therapeutic index value are the results are discussed.

  18. One-Pot Silver Nanoring Synthesis

    NASA Astrophysics Data System (ADS)

    Drogat, Nicolas; Granet, Robert; Sol, Vincent; Krausz, Pierre

    2010-03-01

    Silver colloidal nanorings have been synthesized by reducing silver ions with NaBH4 in trisodium citrate buffers. pH increase, by addition of NaOH, was used to speed up reduction reaction. The UV-vis absorption spectra of resulting silver nanorings showed two peaks accounting for transverse and longitudinal surface plasmon resonance, at ≈400 nm, and between 600 and 700 nm, respectively. The shapes of these silver nanoparticles (nanorings) depended on AgNO3/NaBH4 ratio, pH and reaction temperature. Particles were analysed by transmission electron microscopy, scanning electron microscopy and X-ray diffraction. A reaction pathway is proposed to explain silver nanoring formation.

  19. One-pot silver nanoring synthesis.

    PubMed

    Drogat, Nicolas; Granet, Robert; Sol, Vincent; Krausz, Pierre

    2009-12-16

    Silver colloidal nanorings have been synthesized by reducing silver ions with NaBH4 in trisodium citrate buffers. pH increase, by addition of NaOH, was used to speed up reduction reaction. The UV-vis absorption spectra of resulting silver nanorings showed two peaks accounting for transverse and longitudinal surface plasmon resonance, at ≈400 nm, and between 600 and 700 nm, respectively. The shapes of these silver nanoparticles (nanorings) depended on AgNO3/NaBH4 ratio, pH and reaction temperature. Particles were analysed by transmission electron microscopy, scanning electron microscopy and X-ray diffraction. A reaction pathway is proposed to explain silver nanoring formation.

  20. One-Pot Silver Nanoring Synthesis

    PubMed Central

    2010-01-01

    Silver colloidal nanorings have been synthesized by reducing silver ions with NaBH4 in trisodium citrate buffers. pH increase, by addition of NaOH, was used to speed up reduction reaction. The UV–vis absorption spectra of resulting silver nanorings showed two peaks accounting for transverse and longitudinal surface plasmon resonance, at ≈400 nm, and between 600 and 700 nm, respectively. The shapes of these silver nanoparticles (nanorings) depended on AgNO3/NaBH4 ratio, pH and reaction temperature. Particles were analysed by transmission electron microscopy, scanning electron microscopy and X-ray diffraction. A reaction pathway is proposed to explain silver nanoring formation. PMID:20672109

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