Studies of reaction geometry in oxidation and reduction of the alkaline silver electrode

NASA Technical Reports Server (NTRS)

Butler, E. A.; Blackham, A. U.

1971-01-01

Two methods of surface area estimations of sintered silver electrodes have given roughness factors of 58 and 81. One method is based on constant current oxidation, the other is based on potentiostatic oxidation. Examination of both wire and sintered silver electrodes via scanning electron microscopy at various stages of oxidation have shown that important structural features are mounds of oxide. In potentiostatic oxidations these appear to form on sites instantaneously nucleated while in constant current oxidations progressive nucleation is indicated.

A Technical, User and Cost Comparison Study of Microfiche Duplicate Film Material. Final Report.

ERIC Educational Resources Information Center

Prevel, James J.

A technical, user and cost comparison study was undertaken to provide the Educational Resources Information Clearinghouse (ERIC) staff with data on silver halide, diazo, and vesicular type films for microfiche duplication. This information will allow ERIC to determine if diazo and/or vesicular films should be considered in producing ERIC duplicate…

The role of alternative therapy in the management of partial thickness burns of the face--experience with the use of moist exposed burn ointment (MEBO) compared with silver sulphadiazine.

PubMed

Ang, E S; Lee, S T; Gan, C S; See, P; Chan, Y H; Ng, L H; Machin, D

2000-01-01

Conventional management of partial thickness facial burn wounds includes the use of silver sulphadiazine dressings. Silver sulphadiazine forms an overlying slough that makes wound healing assessment difficult. Moist exposed burn ointment (MEBO) has been proposed as the ideal burn wound dressing both for burns of the face and other sites. Proponents of MEBO claim that it accelerates wound healing and results in scarless wound healing and at the same time reduce bacterial colonisation and the need for analgesics. We present here our experience with MEBO in the management of partial thickness burns of the face. One hundred and fifteen patients with partial thickness burns were randomly assigned to conventional treatment or MEBO. Out of this, 112 were analysed. Thirty-nine patients sustained facial burns; 17 received MEBO and 22 received silver sulphadiazine. Patients were followed up daily until the burn wounds were reduced by 75% of original body surface area (BSA). In patients with facial burns, MEBO was similar to silver sulphadiazine therapy with respect to rate of wound healing. Minimal slough was present over the wounds in MEBO-treated wounds resulting in clearer assessment of healing progression. Advantages of MEBO as compared to silver sulphadiazine in the management of partial thickness burns of the face include convenient change of dressing and easier assessment of healing progression. This suggests that MEBO is a useful alternative therapy for partial thickness burns of the face.

Highly Conductive Nano-Silver Circuits by Inkjet Printing

NASA Astrophysics Data System (ADS)

Zhu, Dongbin; Wu, Minqiang

2018-06-01

Inkjet technology has become popular in the field of printed electronics due to its superior properties such as simple processes and printable complex patterns. Electrical conductivity of the circuits is one of the key factors in measuring the performance of printed electronics, which requires great material properties and a manufactured process. With excellent conductivity and ductility, silver is an ideal material as the wire connecting components. This review summarizes the progress of conductivity studies on inkjet printed nano-silver lines, including ink composition and nanoparticle morphology, deposition of nano-silver lines with uniform and high aspect ratios, sintering mechanisms and alternative methods of thermal sintering. Finally, the research direction on inkjet printed electronics is proposed.

Compatibility Study of Silver Biocide in Drinking Water with Candidate Metals for Crew Exploration Vehicle Potable Water System

NASA Technical Reports Server (NTRS)

Adam, Niklas M.

2009-01-01

The stability of silver biocide, used to keep drinking water on the CEV potable water sterile, is unknown as the system design is still in progress. Silver biocide in water can deplete rapidly when exposed to various metal surfaces. Additionally, silver depletion rates may be affected by the surface-area-to-volume (SA/V) ratios in the water system. Therefore, to facilitate the CEV water system design, it would be advantageous to know the biocide depletion rates in water exposed to the surfaces of these candidate metals at various SA/V ratios. Certain surface treatments can be employed to reduce the depletion rates of silver compared to the base metal. The purpose of this work is to determine the compatibility of specific spaceflight-certified metals that could used in the design of the CEV potable water system with silver biocide as well as understand the effect of surface are to volume ratios of metals used in the construction of the potable water system on the silver concentration.

Green Synthesis of Silver Nanoparticles Using Sodium Alginate and Lignosulphonic Acid Blends

NASA Astrophysics Data System (ADS)

Thakur, Amrita; Reddy, Giridhar

2017-08-01

A simple method based on the principles of green chemistry has been developed to synthesize stable silver nanoparticles (AgNP) for possible biomedical applications. Blend of sodium alginate (SA) and lignosulphonic acid (LS) prepared in the ratio of 80/20 mass percent respectively was used as reducing and stabilizing agent. This blend is biocompatible and has shown drug release ability under physiological conditions. Use of blend has an added advantage as LS has the ability to reduce silver while the blend matrix acts as a stabilizing agent. Effect of precursor concentration (AgNO3) and temperature was investigated. Progress of synthesis was monitored using UV-Vis spectroscopy. Higher temperature and lower silver nitrate concentration showed better synthesis of AgNP.

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.

78 FR 19585 - Change of Address; Biologics License Applications; Technical Amendment

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-02

... Evaluation and Research, Food and Drug Administration, 10903 New Hampshire Ave., Bldg. 22, rm. 1120, Silver... and Research, Food and Drug Administration, 5901B Ammendale Rd., Beltsville, MD 20705. This action is...

Mechanical Recanalization of Subacute Vessel Occlusion in Peripheral Arterial Disease with a Directional Atherectomy Catheter

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

Massmann, Alexander, E-mail: Alexander.Massmann@uks.eu; Katoh, Marcus; Shayesteh-Kheslat, Roushanak

2012-10-15

Purpose: To retrospectively examine the technical feasibility and safety of directional atherectomy for treatment of subacute infrainguinal arterial vessel occlusions. Methods: Five patients (one woman, four men, age range 51-81 years) with peripheral arterial disease who experienced sudden worsening of their peripheral arterial disease-related symptoms during the last 2-6 weeks underwent digital subtraction angiography, which revealed vessel occlusion in native popliteal artery (n = 4) and in-stent occlusion of the superficial femoral artery (n = 1). Subsequently, all patients were treated by atherectomy with the SilverHawk (ev3 Endovascular, USA) device. Results: The mean diameter of treated vessels was 5.1 {+-}more » 1.0 mm. The length of the occlusion ranged 2-14 cm. The primary technical success rate was 100%. One patient experienced a reocclusion during hospitalization due to heparin-induced thrombocytopenia. There were no further periprocedural complications, in particular no peripheral embolizations, until hospital discharge or during the follow-up period of 1 year. Conclusion: The recanalization of infrainguinal arterial vessel occlusions by atherectomy with the SilverHawk device is technically feasible and safe. In our limited retrospective study, it was associated with a high technical success rate and a low procedure-related complication rate.« less

Assessment of antimicrobial effects of food contact materials containing silver on growth of Salmonella Typhimurium.

PubMed

Williams, Katherine; Valencia, Luis; Gokulan, Kuppan; Trbojevich, Raul; Khare, Sangeeta

2017-02-01

Food contact materials containing antibacterial properties are progressively appearing in the market. Items intended to provide antimicrobial effects such as increased shelf life and food safety are incorporating silver materials during the manufacture of such products. This study examined the total silver content, release capacity, and antibacterial activity of three different silver-containing food contact materials: plastic food storage containers, a plastic cutting board, and food wrapping paper. Silver content and release were determined by Inductively Coupled Plasma Mass Spectrometry, and the results showed that, although the amount of silver in each product was similar, migration varied considerably with kind of material and simulant choice. Antimicrobial effect was tested by measuring the growth of Salmonella Typhimurium during or after exposure to the different food contact materials. The results showed that the food storage containers and wrapping paper delayed the growth of S. Typhimurium under certain conditions, but that these effects were short-lived. The strain of S. Typhimurium used in this study was found to be negative for the presence of tested silver resistance genes. The results of this study suggest that a thorough investigation should be required to show/claim the efficacy of silver-containing food contact materials for food safety purposes. Published by Elsevier Ltd.

A case of generalized argyria after ingestion of colloidal silver solution.

PubMed

Kim, Yangho; Suh, Ho Seok; Cha, Hee Jeong; Kim, Suk Hwan; Jeong, Kyoung Sook; Kim, Dong Hoon

2009-03-01

A 58-year-old woman was referred to our hospital due to progressive skin darkening, which began 5 months previously. The patient had strikingly diffuse blue-gray discoloration of the skin, most prominent in sun-exposed areas, especially her face and hands. The oral mucosa, tongue, gums, eye conjunctiva, ears, nail beds, and trunk were also involved. Bluish-gray discoloration of all nails was aggravated by cold weather. She had ingested 1 L of colloidal silver solution daily for approximately 16 months as a traditional remedy. Her serum silver concentration was 381 ng/ml which was a very high (reference level: <15 ng/ml). Light microscopic examination of a punch biopsy specimen from her nose revealed fine, minute, round, and brown-black granules deposited in the basement membrane of hair follicular epithelium. Scanning electron microscopic examination showed electron-dense granules deposited in the intercellular space of sweat glands. Energy disperse X-ray spectrometry analysis demonstrated peaks for silver and sulfur in the dense black deposits. The ingestion of colloidal silver appears to be an increasing practice among patients using alternative health practices. All silver-containing products including colloidal silver should be labeled with a clear warning to prevent argyria, especially in alternative health practices.

A prototype single-port device for pressurized intraperitoneal aerosol chemotherapy. Technical feasibility and local drug distribution.

PubMed

Seitenfus, Rafael; Ferreira, Paulo Roberto Walter; Santos, Gabriel Oliveira Dos; Alves, Rafael José Vargas; Kalil, Antonio Nocchi; Barros, Eduardo Dipp de; Glehen, Olivier; Casagrande, Thaís Andrade Costa; Bonin, Eduardo Aimoré; Silva Junior, Edison Martins da

2017-12-01

To evaluate the technical feasibility and homogeneity of drug distribution of pressurized intraperitoneal aerosol chemotherapy (PIPAC) based on a novel process of intraperitoneal drug application (multidirectional aerosolization). This was an in vivo experimental study in pigs. A single-port device was manufactured at the smallest diameter possible for multidirectional aerosolization of the chemotherapeutic drug under positive intraperitoneal pressure. Four domestic pigs were used in the study, one control animal that received multidirectional microjets of 9 mL/sec for 30 min and three animals that received multidirectional aerosolization (pig 02: 9 mL/sec for 30 min; pigs 03 and 04: 3 mL/sec for 15 min). Aerosolized silver nitrate solution was applied for anatomopathological evaluation of intraperitoneal drug distribution. Injection time was able to maintain the pneumoperitoneum pressure below 20 mmHg. The rate of moderate silver nitrate staining was 45.4% for pig 01, 36.3% for pig 02, 36.3% for pig 03, and 72.7% for pig 04. Intra-abdominal drug distribution had a broad pattern, especially in animals exposed to the drug for 30 min. Our sample of only four animals was not large enough to demonstrate an association between aerosolization and a higher silver nitrate concentration in the stained abdominal regions.

Antimicrobial kinetics of Alstonia scholaris bark extract-mediated AgNPs

NASA Astrophysics Data System (ADS)

Supraja, N.; Prasad, T. N. V. K. V.; David, E.; Giridhara Krishna, T.

2016-06-01

Nanobiotechnology is considered as one of the important branches of nanotechnology, and research on synthesis of nanoscale materials, silver in particular, using plant and plant parts has been progressing rapidly. Herein, we used bark extract of Alstonia scholaris one of the most important medicinal plants to synthesize silver nanoparticles (AgNPs) which exhibited excellent antimicrobial properties against biofilm formed in drinking water PVC pipes. The biosynthesis of silver nanoparticles was done by treating 90 mL of 1 mM AgNO3 aqueous solution with 10 mL of 5 % bark extract. As-prepared silver nanoparticles were characterized using the biophysical techniques such as UV-Vis spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, transmission electron microscopy, and dynamic light scattering for the measurement of hydrodynamic diameter and zeta potential. The kinetics of the antimicrobial activity against PVC biofilm of prepared silver nanoparticles were done using comparative solution suspension time-killing assessments and which are evidenced in Epi-fluorescent microscopic observations.

Diet-derived microRNAs: unicorn or silver bullet?

PubMed

Witwer, Kenneth W; Zhang, Chen-Yu

2017-01-01

In ancient lore, a bullet cast from silver is the only effective weapon against monsters. The uptake of active diet-derived microRNAs (miRNAs) in consumers may be the silver bullet long sought after in nutrition and oral therapeutics. However, the majority of scientists consider the transfer and regulation of consumer's gene activity by these diet-derived miRNAs to be a fantasy akin to spotting a unicorn. Nevertheless, groups like Dr. Chen-Yu Zhang's lab in Nanjing University have stockpiled breathtaking amounts of data to shoot down these naysayers. Meanwhile, Dr. Ken Witwer at John Hopkins has steadfastly cautioned the field to beware of fallacies caused by contamination, technical artifacts, and confirmation bias. Here, Dr. Witwer and Dr. Zhang share their realities of dietary miRNAs by answering five questions related to this controversial field.

[Toxoplasmosis. Anatomo clinical characteristics and morphological indentification of the parasite using the silver-impregnation technic].

PubMed

Villegas González, J; Fastag de Shor, A; Villegas Silva, R

1977-01-01

The clinical and anatomicopathological characteristics of acute and chronic toxoplasmosis are described as they affect different structures and systems. The lesion to adrenal glands is compared to that seen in disseminated herpes simplex; however, the question remains as to why in both congenital infections, necrosis of adrenal glands appears without inflammatory reaction. The investigation of special techniques for localization and identification of Toxoplasma gondii "groups" or cysts, leads to the conclusion that Grocott's silver impregnation technique used for the identification of Entamoeba histolytica is also useful to discover Toxoplasma in tissues.

Inkjet-printed microelectrodes on PDMS as biosensors for functionalized microfluidic systems.

PubMed

Wu, Jianwei; Wang, Ridong; Yu, Haixia; Li, Guijun; Xu, Kexin; Tien, Norman C; Roberts, Robert C; Li, Dachao

2015-02-07

Microfluidic systems based on polydimethylsiloxane (PDMS) have gained popularity in recent years. However, microelectrode patterning on PDMS to form biosensors in microchannels remains a worldwide technical issue due to the hydrophobicity of PDMS and its weak adhesion to metals. In this study, an additive technique using inkjet-printed silver nanoparticles to form microelectrodes on PDMS is presented. (3-Mercaptopropyl)trimethoxysilane (MPTMS) was used to modify the surface of PDMS to improve its surface wettability and its adhesion to silver. The modified surface of PDMS is rendered relatively hydrophilic, which is beneficial for the silver droplets to disperse and thus effectively avoids the coalescence of adjacent droplets. Additionally, a multilevel matrix deposition (MMD) method is used to further avoid the coalescence and yield a homogeneous pattern on the MPTMS-modified PDMS. A surface wettability comparison and an adhesion test were conducted. The resulting silver pattern exhibited good uniformity, conductivity and excellent adhesion to PDMS. A three-electrode electrochemical biosensor was fabricated successfully using this method and sealed in a PDMS microchannel, forming a lab-on-a-chip glucose biosensing system.

The Way Ahead For Maritime UAVS

DTIC Science & Technology

2006-10-23

of possible contract winners including Scan Eagle, Silver Fox, Wasp, Coyote and the USMC Tier I winner Dragon Eye. Technical data for these UAVs are...Neptune’s engine and avionics are placed above the waterline and the airframe is sealed for flotation as well as providing corrosion/water intrusion

Green synthesis of highly stabilized nanocrystalline silver particles by a non-pathogenic and agriculturally important fungus T. asperellum

NASA Astrophysics Data System (ADS)

Mukherjee, P.; Roy, M.; Mandal, B. P.; Dey, G. K.; Mukherjee, P. K.; Ghatak, J.; Tyagi, A. K.; Kale, S. P.

2008-02-01

A controlled and up-scalable biosynthetic route to nanocrystalline silver particles with well-defined morphology using cell-free aqueous filtrate of a non-pathogenic and commercially viable biocontrol agent Trichoderma asperellum is being reported for the first time. A transparent solution of the cell-free filtrate of Trichoderma asperellum containing 1 mM AgNO3 turns progressively dark brown within 5 d of incubation at 25 °C. The kinetics of the reaction was studied using UV-vis spectroscopy. An intense surface plasmon resonance band at ~410 nm in the UV-vis spectrum clearly reveals the formation of silver nanoparticles. The size of the silver particles using TEM and XRD studies is found to be in the range 13-18 nm. These nanoparticles are found to be highly stable and even after prolonged storage for over 6 months they do not show significant aggregation. A plausible mechanism behind the formation of silver nanoparticles and their stabilization via capping has been investigated using FTIR and surface-enhanced resonance Raman spectroscopy.

Tactical and operational response to major incidents: feasibility and reliability of skills assessment using novel virtual environments.

PubMed

Cohen, Daniel; Sevdalis, Nick; Patel, Vishal; Taylor, Michael; Lee, Henry; Vokes, Mick; Heys, Mick; Taylor, David; Batrick, Nicola; Darzi, Ara

2013-07-01

To determine feasibility and reliability of skills assessment in a multi-agency, triple-site major incident response exercise carried out in a virtual world environment. Skills assessment was carried out across three scenarios. The pre-hospital scenario required paramedics to triage and treat casualties at the site of an explosion. Technical skills assessment forms were developed using training syllabus competencies and national guidelines identified by pre-hospital response experts. Non-technical skills were assessed using a seven-point scale previously developed for use by pre-hospital paramedics. The two in-hospital scenarios, focusing on a trauma team leader and a silver/clinical major incident co-ordinator, utilised the validated Trauma-NOTECHS scale to assess five domains of performance. Technical competencies were assessed using an ATLS-style competency scale for the trauma scenario. For the silver scenario, the assessment document was developed using competencies described from a similar role description in a real-life hospital major incident plan. The technical and non-technical performance of all participants was assessed live by two experts in each of the three scenarios and inter-assessor reliability was computed. Participants also self-assessed their performance using identical proformas immediately after the scenarios were completed. Self and expert assessments were correlated (assessment cross-validation). Twenty-three participants underwent all scenarios and assessments. Performance assessments were feasible for both experts as well as the participants. Non-technical performance was generally scored higher than technical performance. Very good inter-rater reliability was obtained between expert raters across all scenarios and both technical and non-technical aspects of performance (reliability range 0.59-0.90, Ps<0.01). Significant positive correlations were found between self and expert assessment in technical skills across all three scenarios (correlation range 0.52-0.84, Ps<0.05), although no such correlations were observed in non-technical skills. This study establishes feasibility and reliability of virtual environment technical and non-technical skills assessment in major incident scenarios for the first time. The development for further scenarios and validated assessment scales will enable major incident planners to utilise virtual technologies for improved major incident preparation and training. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Multiple pulse nanosecond laser induced damage threshold on hybrid mirrors

NASA Astrophysics Data System (ADS)

Vanda, Jan; Muresan, Mihai-George; Bilek, Vojtech; Sebek, Matej; Hanus, Martin; Lucianetti, Antonio; Rostohar, Danijela; Mocek, Tomas; Škoda, Václav

2017-11-01

So-called hybrid mirrors, consisting of broadband metallic surface coated with dielectric reflector designed for specific wavelength, becoming more important with progressing development of broadband mid-IR sources realized using parametric down conversion system. Multiple pulse nanosecond laser induced damage on such mirrors was tested by method s-on-1, where s stands for various numbers of pulses. We show difference in damage threshold between common protected silver mirrors and hybrid silver mirrors prepared by PVD technique and their variants prepared by IAD. Keywords: LIDT,

48 CFR 742.1170-4 - Progress reporting requirements and contract clause.

Code of Federal Regulations, 2010 CFR

2010-10-01

... progress. (b) Because the cognizant technical officer is the individual most familiar with the contractor's performance, the contractor must submit the progress reports directly to the cognizant technical officer. The cognizant technical officer must review the reports and advise the contracting officer, in writing, of any...

Evaluation of the Biocidal Efficacy of Different Forms of Silver Against Cupriavidus (formerly Wautersia) Species Bacteria

NASA Technical Reports Server (NTRS)

Gazda, Daniel B.; Schultz, John R.; Wong, Wing; Algate, Michelle T.; Bryant, Becky; Castro, Victoria A.

2009-01-01

Contingency Water Containers (CWCs) are used to store potable and technical water that is transferred to the International Space Station (ISS) from the Shuttle orbiter vehicles. When CWCs are filled, water from the orbiter galley is passed through an ion exchange/activated carbon cartridge that removes the residual iodine biocide used on Shuttle before silver biocide is added. Removal of iodine and addition of silver is necessary to inhibit microbial growth inside CWCs and maintain compatibility with the water systems in the Russian segment of ISS. As part of nominal water transfer activities, crewmembers collect samples from several CWCs for postflight analysis. Results from the analysis of water transfer samples collected during the docked phases of STS-118/13A.1 and STS-120/10A showed that several of the CWCs contained up to 10(exp 4) CFU/mL of bacteria despite the fact that the silver concentrations in the CWCs were within acceptable limits. The samples contained pure cultures of a single bacteria, a Cupriavidus (formerly Wautersia) species that has been shown to be resistant to metallic biocides. As part of the investigation into the cause and remediation of the bacterial contamination in these CWCs, ground studies were initiated to evaluate the resistance of the Cupriavidus species to the silver biocides used on ISS and to determine the minimum effective concentration for the different forms of silver present in the biocides. The initial findings from those experiments are discussed herein.

Performance and Reliability of Bonded Interfaces for High-Temperature Packaging

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

DeVoto, Douglas

2016-06-08

This is a technical review of the DOE VTO EDT project EDT063, Performance and Reliability of Bonded Interfaces for High-Temperature Packaging. A procedure for analyzing the reliability of sintered-silver through experimental thermal cycling and crack propagation modeling has been outlined and results have been presented.

Education, Technical Progress, and Economic Growth: The Case of Taiwan.

ERIC Educational Resources Information Center

Lin, T.-C.

2003-01-01

Investigates the effect of education and the role of technical progress on economic growth in Taiwan from 1965-2000. Finds that education has a positive and significant effect on growth, but the role of technical progress does not appear to be extraordinarily important. Furthermore, no markedly significant relationships exist between capital and…

Webinar May 17: Fuel Cell Electric Bus Progress Toward Meeting Technical

Science.gov Websites

Targets | News | NREL Webinar May 17: Fuel Cell Electric Bus Progress toward Meeting Technical Targets Webinar May 17: Fuel Cell Electric Bus Progress toward Meeting Technical Targets May 14, 2018 The U.S. Department of Energy's (DOE's) Fuel Cell Technologies Office will present a live webinar titled

Silver Coordination Polymers for Prevention of Implant Infection: Thiol Interaction, Impact on Respiratory Chain Enzymes, and Hydroxyl Radical Induction▿ †

PubMed Central

Gordon, Oliver; Vig Slenters, Tünde; Brunetto, Priscilla S.; Villaruz, Amer E.; Sturdevant, Daniel E.; Otto, Michael; Landmann, Regine; Fromm, Katharina M.

2010-01-01

Prosthetic joint replacements are used increasingly to alleviate pain and improve mobility of the progressively older and more obese population. Implant infection occurs in about 5% of patients and entails significant morbidity and high social costs. It is most often caused by staphylococci, which are introduced perioperatively. They are a source of prolonged seeding and difficult to treat due to antibiotic resistance; therefore, infection prevention by prosthesis coating with nonantibiotic-type anti-infective substances is indicated. A renewed interest in topically used silver has fostered development of silver nanoparticles, which, however, present a potential health hazard. Here we present new silver coordination polymer networks with tailored physical and chemical properties as nanostructured coatings on metallic implant substrates. These compounds exhibited strong biofilm sugar-independent bactericidal activity on in vitro-grown biofilms and prevented murine Staphylococcus epidermidis implant infection in vivo with slow release of silver ions and limited transient leukocyte cytotoxicity. Furthermore, we describe the biochemical and molecular mechanisms of silver ion action by gene screening and by targeting cell metabolism of S. epidermidis at different levels. We demonstrate that silver ions inactivate enzymes by binding sulfhydryl (thiol) groups in amino acids and promote the release of iron with subsequent hydroxyl radical formation by an indirect mechanism likely mediated by reactive oxygen species. This is the first report investigating the global metabolic effects of silver in the context of a therapeutic application. We anticipate that the compounds presented here open a new treatment field with a high medical impact. PMID:20660682

Nickel-silver alloy electrocatalysts for hydrogen evolution and oxidation in an alkaline electrolyte.

PubMed

Tang, Maureen H; Hahn, Christopher; Klobuchar, Aidan J; Ng, Jia Wei Desmond; Wellendorff, Jess; Bligaard, Thomas; Jaramillo, Thomas F

2014-09-28

The development of improved catalysts for the hydrogen evolution reaction (HER) and hydrogen oxidation reaction (HOR) in basic electrolytes remains a major technical obstacle to improved fuel cells, water electrolyzers, and other devices for electrochemical energy storage and conversion. Based on the free energy of adsorbed hydrogen intermediates, theory predicts that alloys of nickel and silver are active for these reactions. In this work, we synthesize binary nickel-silver bulk alloys across a range of compositions and show that nickel-silver alloys are indeed more active than pure nickel for hydrogen evolution and, possibly, hydrogen oxidation. To overcome the mutual insolubility of silver and nickel, we employ electron-beam physical vapor codeposition, a low-temperature synthetic route to metastable alloys. This method also produces flat and uniform films that facilitate the measurement of intrinsic catalytic activity with minimal variations in the surface area, ohmic contact, and pore transport. Rotating-disk-electrode measurements demonstrate that the hydrogen evolution activity per geometric area of the most active catalyst in this study, Ni0.75Ag0.25, is approximately twice that of pure nickel and has comparable stability and hydrogen oxidation activity. Our experimental results are supported by density functional theory calculations, which show that bulk alloying of Ni and Ag creates a variety of adsorption sites, some of which have near-optimal hydrogen binding energy.

Performance and Reliability of Bonded Interfaces for High-temperature Packaging: Annual Progress Report

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

DeVoto, Douglas J.

2017-10-19

As maximum device temperatures approach 200 °Celsius, continuous operation, sintered silver materials promise to maintain bonds at these high temperatures without excessive degradation rates. A detailed characterization of the thermal performance and reliability of sintered silver materials and processes has been initiated for the next year. Future steps in crack modeling include efforts to simulate crack propagation directly using the extended finite element method (X-FEM), a numerical technique that uses the partition of unity method for modeling discontinuities such as cracks in a system.

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

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-15

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

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

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-26

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

The Myth of the Silver Bullet: Does Technical Superiority Equate to Battlefield Success?

DTIC Science & Technology

2012-03-30

Victorian period alone, the British army suffered significant defeats in India and Zululand and strategic defeat in Afghanistan, Sudan, and the Transvaal.28...capability of their systems and fought the battle in a fashion that maximized their weapons potential. It was, “Through the evolution of technological

Performance and Reliability of Bonded Interfaces for High-Temperature Packaging; NREL (National Renewable Energy Laboratory)

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

DeVoto, Douglas

2015-06-10

This is a technical review of the DOE VTO EDT project EDT063, Performance and Reliability of Bonded Interfaces for High-Temperature Packaging. A procedure for analyzing the reliability of sintered-silver through experimental thermal cycling and crack propagation modeling has been outlined and results have been presented.

TRADOC RAM (Reliability, Availability, Maintainability) Data Evaluation System (TRADES). Part 5. System Technical Paper.

DTIC Science & Technology

1982-02-05

McCo0ne Sheridan’"-M nSdHill Silver Dow Powder River Wibaux Jefferson Stillwater The following counties in Wyoming: Judith Basin Sweet Grass Albany...Sweetwater Lassen Sonoma Johnson Teton Misalera Stanislaus Lincoln Uinta Main Sutter Park Washakie Maripoaa Tehama"Sheridan Mendocino Trinity Merced

25 CFR 30.111 - When should the tribal governing body or school board request technical assistance?

Code of Federal Regulations, 2011 CFR

2011-04-01

... request technical assistance? 30.111 Section 30.111 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR EDUCATION ADEQUATE YEARLY PROGRESS Defining Adequate Yearly Progress Technical Assistance § 30.111 When should the tribal governing body or school board request technical assistance? In order to...

25 CFR 30.110 - What is the process for requesting technical assistance to develop an alternative definition of AYP?

Code of Federal Regulations, 2011 CFR

2011-04-01

..., DEPARTMENT OF THE INTERIOR EDUCATION ADEQUATE YEARLY PROGRESS Defining Adequate Yearly Progress Technical Assistance § 30.110 What is the process for requesting technical assistance to develop an alternative... 25 Indians 1 2011-04-01 2011-04-01 false What is the process for requesting technical assistance...

25 CFR 30.110 - What is the process for requesting technical assistance to develop an alternative definition of AYP?

Code of Federal Regulations, 2010 CFR

2010-04-01

... 25 Indians 1 2010-04-01 2010-04-01 false What is the process for requesting technical assistance..., DEPARTMENT OF THE INTERIOR EDUCATION ADEQUATE YEARLY PROGRESS Defining Adequate Yearly Progress Technical Assistance § 30.110 What is the process for requesting technical assistance to develop an alternative...

Evaluation of the Effects of Honey on Acute-Phase Deep Burn Wounds

PubMed Central

Nakajima, Yukari; Mukai, Kanae; Nasruddin; Komatsu, Emi; Iuchi, Terumi; Kitayama, Yukie; Sugama, Junko; Nakatani, Toshio

2013-01-01

This study aimed to clarify the effects of honey on acute-phase deep burn wounds. Two deep burn wounds were created on mice which were divided into four groups: no treatment, silver sulfadiazine, manuka honey, and Japanese acacia honey. Wound sizes were calculated as expanded wound areas and sampled 30 minutes and 1–4 days after wounding for histological observation. The wound sections were subjected to hematoxylin and eosin and immunohistological staining to detect necrotic cells, apoptotic cells, neutrophils, and macrophages. The no treatment group formed a scar. The redness around the wound edges in the silver sulfadiazine group was the most intense. All groups exhibited increased wound areas after wounding. The proportions of necrotic cells and the numbers of neutrophils in the manuka and acacia honey groups were lower than those in the no treatment and silver sulfadiazine groups until day 3; however, there were no significant differences between all groups on day 4. These results show that honey treatment on deep burn wounds cannot prevent wound progression. Moreover, comparing our observations with those of Jackson, there are some differences between humans and animals in this regard, and the zone of hyperemia and its surrounding area fall into necrosis, which contributes to burn wound progression. PMID:24348720

Evaluation of the effects of honey on acute-phase deep burn wounds.

PubMed

Nakajima, Yukari; Mukai, Kanae; Nasruddin; Komatsu, Emi; Iuchi, Terumi; Kitayama, Yukie; Sugama, Junko; Nakatani, Toshio

2013-01-01

This study aimed to clarify the effects of honey on acute-phase deep burn wounds. Two deep burn wounds were created on mice which were divided into four groups: no treatment, silver sulfadiazine, manuka honey, and Japanese acacia honey. Wound sizes were calculated as expanded wound areas and sampled 30 minutes and 1-4 days after wounding for histological observation. The wound sections were subjected to hematoxylin and eosin and immunohistological staining to detect necrotic cells, apoptotic cells, neutrophils, and macrophages. The no treatment group formed a scar. The redness around the wound edges in the silver sulfadiazine group was the most intense. All groups exhibited increased wound areas after wounding. The proportions of necrotic cells and the numbers of neutrophils in the manuka and acacia honey groups were lower than those in the no treatment and silver sulfadiazine groups until day 3; however, there were no significant differences between all groups on day 4. These results show that honey treatment on deep burn wounds cannot prevent wound progression. Moreover, comparing our observations with those of Jackson, there are some differences between humans and animals in this regard, and the zone of hyperemia and its surrounding area fall into necrosis, which contributes to burn wound progression.

14 CFR 1274.701 - Suspension or termination.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Agreement if the recipient is not making anticipated technical progress, if the recipient materially changes...) Similarly, the recipient may terminate the agreement if, for example, technical progress is not being made, if the commercial recipient shifts its technical emphasis, or if other technological advances have...

14 CFR 1274.701 - Suspension or termination.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Agreement if the recipient is not making anticipated technical progress, if the recipient materially changes...) Similarly, the recipient may terminate the agreement if, for example, technical progress is not being made, if the commercial recipient shifts its technical emphasis, or if other technological advances have...

Adolescent growth and pubertal progression in the Silver-Russell syndrome.

PubMed Central

Davies, P S; Valley, R; Preece, M A

1988-01-01

The pattern of growth and development of 18 adolescent children with the Silver-Russell syndrome was studied. Mature height was about -3.6 standard deviation scores in both sexes. This is comparable to the height reduction at diagnosis, which has been reported previously. The pattern of puberty and adolescent growth was essentially normal and occurred at a marginally earlier time than normal, although in this small series the differences were not significant. In the girls there was a tendency to gain subcutaneous fat after puberty. This trend was not apparent in the boys. PMID:3348659

Biofilm formation on titanium implants counteracted by grafting gallium and silver ions.

PubMed

Cochis, Andrea; Azzimonti, Barbara; Della Valle, Cinzia; Chiesa, Roberto; Arciola, Carla Renata; Rimondini, Lia

2015-03-01

Biofilm-associated infections remain the leading cause of implant failure. Thanks to its established biocompatibility and biomechanical properties, titanium has become one of the most widely used materials for bone implants. Engineered surface modifications of titanium able to thwart biofilm formation while endowing a safe anchorage to eukaryotic cells are being progressively developed. Here surfaces of disks of commercial grade 2 titanium for bone implant were grafted with gallium and silver ions by anodic spark deposition. Scanning electron microscopy of the surface morphology and energy dispersive X-ray spectroscopy were used for characterization. Gallium-grafted titanium was evaluated in comparison with silver-grafted titanium for both in vivo and in vitro antibiofilm properties and for in vitro compatibility with human primary gingival fibroblasts. Surface-modified materials showed: (i) homogeneous porous morphology, with pores of micrometric size; (ii) absence of cytotoxic effects; (iii) ability to support in vitro the adhesion and spreading of gingival fibroblasts; and (iv) antibiofilm properties. Although both silver and gallium exhibited in vitro strong antibacterial properties, in vivo gallium was significantly more effective than silver in reducing number and viability of biofilm bacteria colonies. Gallium-based treatments represent promising titanium antibiofilm coatings to develop new bone implantable devices for oral, maxillofacial, and orthopedic applications. © 2014 Wiley Periodicals, Inc.

Ligand exchange in ionic systems and its effect on silver nucleation and growth.

PubMed

Abbott, Andrew P; Azam, Muhammad; Frisch, Gero; Hartley, Jennifer; Ryder, Karl S; Saleem, Saima

2013-10-28

The electrodeposition of metals from ionic solutions is intrinsically linked to the reactivity of the solute ions. When metal salts dissolve, the exchange of the anion with the molecular and ionic components from solution affects the speciation and therefore the characteristics of metal reduction. This study investigates the nucleation mechanism, deposition kinetics, metal speciation and diffusion coefficients of silver salts dissolved in Deep Eutectic Solvents. The electrochemical reduction of AgCl, AgNO3 and Ag2O is studied in 1 : 2 choline chloride : ethylene glycol and 1 : 2 choline chloride : urea. Cyclic voltammetry is used to evaluate electrochemical kinetics. Detailed analysis of chronoamperometric data shows that silver deposits form via multiple 3D nucleation with mass transport controlled hemispherical growth. The nucleation mechanism was found to be potential dependent, varying from progressive to instantaneous as the reduction potential becomes more cathodic. Diffusion coefficients are determined using three different methods. Trends are rationalised in terms of solvent viscosity and silver speciation analysis with EXAFS. The morphology of electroreduced silver is investigated with scanning electron microscopy and shows that deposits from the urea based liquid form more dense morphologies than those from the ethylene glycol based liquid.

Progress in Scientific and Technical Communications, 1968 Annual Report.

ERIC Educational Resources Information Center

Federal Council for Science and Technology, Washington, DC. Committee on Scientific and Technical Information.

This sixth annual report describes progress achieved by the Federal Government in improving the communication of scientific and technical information to support and enhance national science and technology. Included in the report are details regarding the scientific and technical activities of individual Federal Agencies, such as the Atomic Energy…

Bus Rapid Transit system’s influence on urban development: An inquiry to Boston and Seoul BRT systems’ technical characteristics

NASA Astrophysics Data System (ADS)

Prayogi, Lutfi

2018-03-01

This article explores the relation between bus rapid transit (BRT) system and urban development. This article was written through a multi-staged comprehensive literature review. It includes a general overview of widely acknowledged BRT technical characteristics. It explains the approach taken in understanding the relation between BRT system provision and urban development around the system. Findings regarding the influence of Boston Silver Line 4 and 5 and Seoul BRT systems on urban development around the systems are quoted and used as case studies. Investigation on the technical characteristics of Boston SL4/5 and Seoul BRT systems are provided. This article shows that the two BRT systems that influence urban development around the systems have technical characteristics that enable the BRT systems to have high performance. However, while the quoted BRT systems can influence urban development, they have significantly different performance.

48 CFR 2452.242-71 - Contract management system.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., concise summary of technical progress made and the costs incurred for each task during the reporting... technical progress made for each task during the reporting period; and (B) Identifies problems, or potential... and progress reporting as described herein. (b) The contract management system shall consist of two...

Metal plasmon-coupled fluorescence imaging and label free coenzyme detection in cells

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

Zhang, Jian, E-mail: jian@cfs.bioment.umaryland.edu; Fu, Yi; Li, Ge

2012-08-31

Highlights: Black-Right-Pointing-Pointer Metal nanoparticle for fluorescence cell imaging. Black-Right-Pointing-Pointer Non-invasive emission detection of coenzyme in cell on time-resolved confocal microscope. Black-Right-Pointing-Pointer Near-field interaction of flavin adenine dinucleotide with silver substrate. Black-Right-Pointing-Pointer Isolation of emissions by coenzymes from cellular autofluorescence on fluorescence cell imaging. -- Abstract: Flavin adenine dinucleotide (FAD) is a key metabolite in cellular energy conversion. Flavin can also bind with some enzymes in the metabolic pathway and the binding sites may be changed due to the disease progression. Thus, there is interest on studying its expression level, distribution, and redox state within the cells. FAD is naturally fluorescent,more » but it has a modest extinction coefficient and quantum yield. Hence the intrinsic emission from FAD is generally too weak to be isolated distinctly from the cellular backgrounds in fluorescence cell imaging. In this article, the metal nanostructures on the glass coverslips were used as substrates to measure FAD in cells. Particulate silver films were fabricated with an optical resonance near the absorption and the emission wavelengths of FAD which can lead to efficient coupling interactions. As a result, the emission intensity and quantum yield by FAD were greatly increased and the lifetime was dramatically shortened resulting in less interference from the longer lived cellular background. This feature may overcome the technical limits that hinder the direct observation of intrinsically fluorescent coenzymes in the cells by fluorescence microscopy. Fluorescence cell imaging on the metallic particle substrates may provide a non-invasive strategy for collecting the information of coenzymes in cells.« less

Improvements in purification of silver nanowires by decantation and fabrication of flexible transparent electrodes. Application to capacitive touch sensors.

PubMed

Mayousse, Céline; Celle, Caroline; Moreau, Eléonore; Mainguet, Jean-François; Carella, Alexandre; Simonato, Jean-Pierre

2013-05-31

Transparent flexible electrodes made of metallic nanowires, and in particular silver nanowires (AgNWs), appear as an extremely promising alternative to transparent conductive oxides for future optoelectronic devices. Though significant progresses have been made the last few years, there is still some room for improvement regarding the synthesis of high quality silver nanowire solutions and fabrication process of high performance electrodes. We show that the commonly used purification process can be greatly simplified through decantation. Using this process it is possible to fabricate flexible electrodes by spray coating with sheet resistance lower than 25 Ω sq⁻¹ at 90% transparency in the visible spectrum. These electrodes were used to fabricate an operative transparent flexible touch screen. To our knowledge this is the first reported AgNW based touch sensor relying on capacitive technology.

ANNUAL REPORT, JULY 1, 1957

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

None

1958-10-31

The progress and trends of research are presented along with a description of operational, service, end administrative activities. Some scientific and technical details are given on research programs in the physical sciences, life sciences, and engineering, however, more complete technical information is available in quarterly progress reports, BNL technical reports, and scientific and technical periodicals. A bibliography of these publications is appended. (For preceding period see BNL-426.) (D.E.B.)

20 CFR 411.180 - What is timely progress toward self-supporting employment?

Code of Federal Regulations, 2010 CFR

2010-04-01

... certificate or vocational or technical training that will enhance your ability to return to work. In addition...-secondary education requirement or vocational or technical training requirement in the applicable progress... this 12-month period; or (iv) You must have been enrolled in a vocational or technical training program...

Overcoming the limitations of silver nanowire electrodes for light emitting applications

NASA Astrophysics Data System (ADS)

Chen, Dustin Yuan

The global lighting market is projected to exceed 100 billion dollars by 2020, undergoing rapid transitions driven by technological advancements. In conjunction with increased demand for new technology, global regulations have become increasingly stringent, mandating the development and implementation of more fuel-efficient light sources. As prior generations of lighting technology such as incandescent bulbs and florescent lighting progressively become phased out, newer technologies such as light emitting diodes (LEDs) and organic light emitting diodes (OLEDs) have become progressively popular and commonplace. Though they still lag behind LEDs in terms of market penetration, OLEDs have garnered increasing amounts of attention in recent years due to unique attributes such as their exotic and large scale form factors, mechanical flexibility, and potential for high volume, low-cost manufacturing. Unfortunately, the costs for OLED manufacturing are currently still prohibitively high for several applications, with the anode and substrate representing 20-25 percent of this total cost. Significant technical and processing improvements for OLED substrates are of utmost necessity for fiscal cost reduction and commercialization of OLED technology. Silver nanowires have gained traction as a potential replacement for the current status quo, indium tin oxide (ITO) due to attributes such as flexibility, low cost processing, and high optoelectronic properties. However, due to nanoscale size effects, the integration of silver nanowires in both process flows and operational use has proven to be problematic. This work makes several key contributions towards enabling the use of silver nanowires for practical and commercial applications within the lighting industry. First, a novel method for the fabrication of a high temperature-stable, flexible substrate with surface roughness (Ra) < 2 nm is presented, based on atomic layer deposition of a conformal metal oxide film on silver nanowires. This development of a thermally stable AgNW based substrate is critical for the future of flexible OLEDs, as both polymers and AgNWs are unstable at elevated temperatures required for certain OLED processing. However, at the time publication, no solutions existed for flexible OLED substrates simultaneously having thermal stability in excess of 230 °C for more than a few minutes while maintaining a smooth surface for subsequent device fabrication. The thermally stable silver nanowires developed in this work are able to withstand temperatures of 500 °C in ramping tests, and when integrated with a thermally stable polymer matrix, withstand temperatures of 300 °C for at least 6 hours, representing an increase in allowable processing temperatures of 70 °C for several hours longer. Resulting polymer light emitting devices (PLEDs) requiring high temperature processing fabricated on this thermally stable exhibit comparable performance to the same devices fabricated on ITO, validating its compatibility for integration in traditional process flows, and validity for use in extreme processing conditions. Secondly, the aforementioned method is applied to understanding the electrical stability of silver nanowires. At the time of publication, previous works on the electrical failure of silver nanowires centered on the observation of failure under current flow, without a solution offered for how to mitigate the phenomenon. However, because the underlying purpose of these electrodes is to transport current, providing a solution for the failure flow is paramount to the success of AgNWs in future commercial applications. The importance of the development of this solution cannot be understated, especially in light of the fact that silver nanowires have been shown to fail under electrical stresses below typical operating conditions of various optoelectronic devices. The same technique mentioned previously can be leveraged for electrically stable silver nanowire networks, which show significant morphological stability over pristine silver nanowires when electrically stressed at normal operating conditions for OLEDs. These electrically stable substrates were able to produce high performance OLEDs with lifetimes 140% longer than the same devices fabricated on ITO, and 20% higher than non-electrically stable AgNW-based substrates. Thirdly, the thermally and electrically stable substrate was used to fabricate a high performing perovskite quantum dot light-emitting device exhibiting high flexibility. The use of quantum dots instead of perovskite precursors and post treatment to convert the precursors to perovskite allowed for several new innovations. Due to the elimination of highly polar solvents typically required with perovskite precursors, a broadened range of architectures can be achieved. Furthermore, due to the small dimensions of the quantum dots in contrast to thick films of perovskite formed from precursors, the active layer can extremely thin, allowing for high mechanical flexibility. The performance metrics achieved of 10.4 cd/A, 8.1 lm/W, and 2.6% EQE at a brightness of 1000 cd/m2 were enabled in part by the substrate, which further allowed for the high mechanical performance. The electroluminescence performance of the perovskite quantum dot LEDs was found to be virtually fully recoverable after being subjected to a bending radius of 2.5 mm, or repeated cycles of bending and unbending to a 4 mm radius, representing the first report of a highly flexible and mechanically perovskite quantum dot light emitting device with high electroluminescence performance. The improved stability of AgNWs with regards to both manufacturing and operational use, in addition to proof of concept in various light emitting devices demonstrates the potential of this technology for large-scale, commercial lighting applications.

Water Treatment Systems Make a Big Splash

NASA Technical Reports Server (NTRS)

2004-01-01

In the 1960s, NASA's Manned Space Center (now known as Johnson Space Center) and the Garrett Corporation, Air Research Division, conducted a research program to develop a small, lightweight water purifier for the Apollo spacecraft that would require minimal power and would not need to be monitored around-the-clock by astronauts in orbit. The 9-ounce purifier, slightly larger than a cigarette pack and completely chlorine-free, dispensed silver ions into the spacecraft s water supply to successfully kill off bacteria. A NASA Technical Brief released around the time of the research reported that the silver ions did not impart an unpleasant taste to the water. NASA s ingenuity to control microbial contamination in space caught on quickly, opening the doors for safer methods of controlling water pollutants on Earth.

Feasibility Study of Economics and Performance of Solar Photovoltaics at the Chino Mine in Silver City, New Mexico. A Study Prepared in Partnership with the Environmental Protection Agency for the RE-Powering America's Land Initiative: Siting Renewable Energy on Potentially Contaminated Land and Mine Sites

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

Kiatreungwattana, K.; Geiger, J.; Healey, V.

The U.S. Environmental Protection Agency (EPA), in accordance with the RE-Powering America's Land initiative, selected the Chino Mine site in Silver City, New Mexico, for a feasibility study of renewable energy production. The National Renewable Energy Laboratory (NREL) provided technical assistance for this project. The purpose of this report is to assess the site for a possible photovoltaic (PV) system installation and estimate the cost, performance, and site impacts of different PV options. In addition, the report recommends financing options that could assist in the implementation of a PV system at the site.

Silver Nanoparticles: An Influential Element in Plant Nanobiotechnology.

PubMed

Sarmast, Mostafa K; Salehi, H

2016-07-01

Profound interest and progress has been made since the invention of nanotechnology in 1959. However, its application in plant tissue culture and biotechnology has not been fully acknowledged in parallel with other facets of this technology. In this manuscript, the AgNPs effects on plant tissue culture and biotechnology encompass their antimicrobial effects and their mechanisms of action addressed to some extends. Moreover, their effects on seedling growth also reviewed. Most of the presented papers in the field of plant science have focused on antimicrobial effects of silver nanoparticles but its interesting inhibitory effects of plant senescence phytohormone ethylene, most likely can open a new window for future research.

Improved Understanding of In Situ Chemical Oxidation. Technical Objective 2: Soil Reactivity

DTIC Science & Technology

2009-05-01

each reaction tube. The reagents ( sulfuric acid /potassium dichromate/mercury sulfate ) were prepared following standard methods (APHA, 1998). When...reaction tubes. A volume (~20 mL) of potassium dichromate digestion solution (potassium dichromate (BDH Laboratories), sulfuric acid (EM Science...and mercury sulphate (EM Science)) and a sulfuric acid reagent solution ( sulfuric acid (EM Science) and silver sulphate (Alfa Aesar)) were added to

Mass production compatible fabrication techniques of single-crystalline silver metamaterials and plasmonics devices

NASA Astrophysics Data System (ADS)

Rodionov, Ilya A.; Baburin, Alexander S.; Zverev, Alexander V.; Philippov, Ivan A.; Gabidulin, Aidar R.; Dobronosova, Alina A.; Ryzhova, Elena V.; Vinogradov, Alexey P.; Ivanov, Anton I.; Maklakov, Sergey S.; Baryshev, Alexander V.; Trofimov, Igor V.; Merzlikin, Alexander M.; Orlikovsky, Nikolay A.; Rizhikov, Ilya A.

2017-08-01

During last 20 years, great results in metamaterials and plasmonic nanostructures fabrication were obtained. However, large ohmic losses in metals and mass production compatibility still represent the most serious challenge that obstruct progress in the fields of metamaterials and plasmonics. Many recent research are primarily focused on developing low-loss alternative materials, such as nitrides, II-VI semiconductor oxides, high-doped semiconductors, or two-dimensional materials. In this work, we demonstrate that our perfectly fabricated silver films can be an effective low-loss material system, as theoretically well-known. We present a fabrication technology of plasmonic and metamaterial nanodevices on transparent (quartz, mica) and non-transparent (silicon) substrates by means of e-beam lithography and ICP dry etch instead of a commonly-used focused ion beam (FIB) technology. We eliminate negative influence of litho-etch steps on silver films quality and fabricate square millimeter area devices with different topologies and perfect sub-100 nm dimensions reproducibility. Our silver non-damage fabrication scheme is tested on trial manufacture of spasers, plasmonic sensors and waveguides, metasurfaces, etc. These results can be used as a flexible device manufacture platform for a broad range of practical applications in optoelectronics, communications, photovoltaics and biotechnology.

Silver nanoparticle based antibacterial methacrylate hydrogels potential for bone graft applications.

PubMed

González-Sánchez, M Isabel; Perni, Stefano; Tommasi, Giacomo; Morris, Nathanael Glyn; Hawkins, Karl; López-Cabarcos, Enrique; Prokopovich, Polina

2015-05-01

Infections are frequent and very undesired occurrences after orthopedic procedures; furthermore, the growing concern caused by the rise in antibiotic resistance is progressively dwindling the efficacy of such drugs. Artificial bone graft materials could solve some of the problems associated with the gold standard use of natural bone graft such as limited bone material, pain at the donor site and rejections if donor tissue is used. We have previously described new acrylate base nanocomposite hydrogels as bone graft materials. In the present paper, we describe the integration of silver nanoparticles in the polymeric mineralized biomaterial to provide non-antibiotic antibacterial activity against Staphylococcus epidermidis and Methicillin-resistant Staphylococcus aureus. Two different crosslinking degrees were tested and the silver nanoparticles were integrated into the composite matrix by means of three different methods: entrapment in the polymeric hydrogel before the mineralization; diffusion during the process of calcium phosphate crystallization and adsorption post-mineralization. The latter being generally the most effective method of encapsulation; however, the adsorption of silver nanoparticles inside the pores of the biomaterial led to a decreasing antibacterial activity for adsorption time longer than 2 days. Copyright © 2015. Published by Elsevier B.V.

Silver nanoparticle based antibacterial methacrylate hydrogels potential for bone graft applications

PubMed Central

González-Sánchez, M. Isabel; Perni, Stefano; Tommasi, Giacomo; Morris, Nathanael Glyn; Hawkins, Karl; López-Cabarcos, Enrique; Prokopovich, Polina

2015-01-01

Infections are frequent and very undesired occurrences after orthopedic procedures; furthermore, the growing concern caused by the rise in antibiotic resistance is progressively dwindling the efficacy of such drugs. Artificial bone graft materials could solve some of the problems associated with the gold standard use of natural bone graft such as limited bone material, pain at the donor site and rejections if donor tissue is used. We have previously described new acrylate base nanocomposite hydrogels as bone graft materials. In the present paper, we describe the integration of silver nanoparticles in the polymeric mineralized biomaterial to provide non-antibiotic antibacterial activity against Staphylococcus epidermidis and Methicillin-resistant Staphylococcus aureus. Two different crosslinking degrees were tested and the silver nanoparticles were integrated into the composite matrix by means of three different methods: entrapment in the polymeric hydrogel before the mineralization; diffusion during the process of calcium phosphate crystallization and adsorption post-mineralization. The latter being generally the most effective method of encapsulation; however, the adsorption of silver nanoparticles inside the pores of the biomaterial led to a decreasing antibacterial activity for adsorption time longer than 2 days. PMID:25746278

Evaporation by mechanical vapor recompression. Technical progress report, September 1-December 31, 1979

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

Iverson, C.H.; Coury, G.E.

1979-01-01

Progress to date in the development of a study of the application of the technologies of mechanical vapor recompression and falling film evaporators as applied to the beet sugar industry is reported. Progress is reported in the following areas: technical literature search and plant visitations of existing applications of VR/FFE.

25 CFR 30.109 - Will the Secretary provide assistance in developing an alternative AYP definition?

Code of Federal Regulations, 2011 CFR

2011-04-01

... EDUCATION ADEQUATE YEARLY PROGRESS Defining Adequate Yearly Progress Technical Assistance § 30.109 Will the... Bureau, shall provide technical assistance either directly or through contract to the tribal governing...

25 CFR 30.109 - Will the Secretary provide assistance in developing an alternative AYP definition?

Code of Federal Regulations, 2010 CFR

2010-04-01

... EDUCATION ADEQUATE YEARLY PROGRESS Defining Adequate Yearly Progress Technical Assistance § 30.109 Will the... Bureau, shall provide technical assistance either directly or through contract to the tribal governing...

MOLECULAR DYNAMICS STUDY OF SILVER PARTICLES FOR LOW TEMPERATURE LEAD FREE INTERCONNECT APPLICATIONS. (R831489)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Monitoring the Durability Performance of Concrete in Nuclear Waste Containment. Technical Progress Report No. 3

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

Ulm, Franz-Josef

2000-03-31

OAK-B135 Monitoring the Durability Performance of Concrete in Nuclear Waste Containment. Technical Progress Report No. 3(NOTE: Part II A item 1 indicates ''PAPER'', but a report is attached electronically)

Crosscutting Technology Development at the Center for Advanced Separation Technologies

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

Christopher E. Hull

2006-09-30

This Technical Progress Report describes progress made on the twenty nine subprojects awarded in the second year of Cooperative Agreement DE-FC26-02NT41607: Crosscutting Technology Development at the Center for Advanced Separation Technologies. This work is summarized in the body of the main report: the individual sub-project Technical Progress Reports are attached as Appendices.

CROSSCUTTING TECHNOLOGY DEVELOPMENT AT THE CENTER FOR ADVANCED SEPARATION TECHNOLOGIES

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

Christopher E. Hull

2006-05-15

This Technical Progress Report describes progress made on the twenty nine subprojects awarded in the second year of Cooperative Agreement DE-FC26-02NT41607: Crosscutting Technology Development at the Center for Advanced Separation Technologies. This work is summarized in the body of the main report: the individual sub-project Technical Progress Reports are attached as Appendices.

The Development and Technical Adequacy of Seventh-Grade Reading Comprehension Measures in a Progress Monitoring Assessment System. Technical Report #1102

ERIC Educational Resources Information Center

Park, Bitnara Jasmine; Alonzo, Julie; Tindal, Gerald

2011-01-01

This technical report describes the process of development and piloting of reading comprehension measures that are appropriate for seventh-grade students as part of an online progress screening and monitoring assessment system, http://easycbm.com. Each measure consists of an original fictional story of approximately 1,600 to 1,900 words with 20…

Development of Technology for Enrichment of Silver Containing Ores

NASA Astrophysics Data System (ADS)

Shekiladze, Asmati; Kavtelashvili, Otari; Bagnashvili, Mamuka

2016-10-01

The progress of Georgian economics is substantially associated with a development of new deposits of mineral resources. Among them is the David-Gareji deposit where at present the intensive searching geological works are performed. The work goal involves the elaboration of the technology for processing of silver-containing quartz-barite ores. Without its development the mining of more valuable gold-polymetallic ores is impossible. Because of ore complexity silver and barite are considered in a common technological aspect. The investigations were carried out on the representative samples of quartz-barite ores containing 78-88 g/ton of silver and 27-29 % of silver is a nugget in the form of the simple sulphides and chlorides. The ore is characterized by fine coalescence of barite and ore-generating minerals. Non-ferrous metals haven't any industrial value because of their very low content. Therefore, for the processing of the ores under study the direct selective scheme of flotation enrichment was chosen and the formula of optimal reagent regime was elaborated. Potassium xanthogenate is used as a collector for flotation of silver minerals and pine oil- as a foaming agent. The effect of the pulp - pH and medium temperature on silver flotation was studied. It was established that the silver is actively floats in neutral medium. For barite flotation the various collectors were tested: sulfidezid cotton oil-soap stock, soaps of fatty acids and alkyl sulphates of C12 - C16 row, among the “Baritol” is the most efficient one. Depression of the barren rock was carried out by liquid glass in alkaline medium. The effect of pulp pH on barite flotation has been investigated. The best results were obtained at pH=8.5. The increase of the pulp alkalinity has no essential effect on the indexes of the barite enrichment. Conditional concentrate of the barite is obtained by two fold purification of the main flotation concentrate by the addition of the liquid glass to the re-purification operations. On the basis of laboratory investigations for silver-containing ores of David-Gareji deposit the technological scheme is recommended which implies the ore milling to 82 % class -074 mm, flotation of the silver minerals and the barite flotation from the tails of this operation by two-fold re-purification of the rough concentrate. The optimal parameters of the receipt of the reagent regime are: potassium butylxantogenate and pine oil-in the silver flotation; sodium carbonate, liquid glass, “Baritol”- in the barite main flotation and liquid glass in the repurification operations. Silver concentrate containing 680 g/ton of silver by extraction of 92.21% and barite concentrate, content - 92.11%, extraction - 81.85% are obtained.

Silver-free Metallization Technology for Producing High Efficiency, Industrial Silicon Solar Cells

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

Michaelson, Lynne M.; Munoz, Krystal; Karas, Joseph

The goal of this project is to provide a commercially viable Ag-free metallization technology that will both reduce cost and increase efficiency of standard silicon solar cells. By removing silver from the front grid metallization and replacing it with lower cost nickel, copper, and tin metal, the front grid direct materials costs will decrease. This reduction in material costs should provide a path to meeting the Sunshot 2020 goal of 1 dollar / W DC. As of today, plated contacts are not widely implemented in large scale manufacturing. For organizations that wish to implement pilot scale manufacturing, only two equipmentmore » choices exist. These equipment manufacturers do not supply plating chemistry. The main goal of this project is to provide a chemistry and equipment solution to the industry that enables reliable manufacturing of plated contacts marked by passing reliability results and higher efficiencies than silver paste front grid contacts. To date, there have been several key findings that point to plated contacts performing equal to or better than the current state of the art silver paste contacts. Poor adhesion and reliability concerns are a few of the hurdles for plated contacts, specifically plated nickel directly on silicon. A key finding of the Phase 1 budget period is that the plated contacts have the same adhesion as the silver paste controls. This is a huge win for plated contacts. With very little optimization work, state of the art electrical results for plated contacts on laser ablated lines have been demonstrated with efficiencies up to 19.1% and fill factors ~80% on grid lines 40-50 um wide. The silver paste controls with similar line widths demonstrate similar electrical results. By optimizing the emitter and grid design for the plated contacts, it is expected that the electrical performance will exceed the silver paste controls. In addition, cells plated using Technic chemistry and equipment pass reliability testing; i.e. 1000 hours damp heat and 200 thermal cycles, with results similar to silver paste control cells. 100 cells have been processed through Technic’s novel demo plating tool built and installed during budget period 2. This plating tool performed consistently from cell to cell, providing gentle handling for the solar cells. An agreement has been signed with a cell manufacturer to process their cells through our plating chemistry and equipment. Their main focus for plated contacts is to reduce the direct materials cost by utilizing nickel, copper, and tin in place of silver paste. Based on current market conditions and cost model calculations, the overall savings offered by plated contacts is only 3.5% dollar/W versus silver paste contacts; however, the direct materials savings depend on the silver market. If silver prices increase, plated contacts may find a wider adoption in the solar industry in order to keep the direct materials costs down for front grid contacts.« less

Generation and focusing of pulsed intense ion beams. Technical progress report, 1 October 1982 - 30 September, 1983

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

Hammer, D.A.; Kusse, B.R.; Sudan, R.N.

1983-07-01

The progress on this contract is described in three parts. The first deals with the technical operation of the LION accelerator. The second and third parts are concerned with the experimental results.

New hermetic sealing material for vacuum brazing of stainless steels

NASA Astrophysics Data System (ADS)

Hildebrandt, S.; Wiehl, G.; Silze, F.

2016-03-01

For vacuum brazing applications such as in vacuum interrupter industry Hermetic Sealing Materials (HSM) with low partial pressure are widely used. AgCu28 dominates the hermetic sealing market, as it has a very good wetting behavior on copper and metallized ceramics. Within recent decades wetting on stainless steel has become more and more important. However, today the silver content of HSMs is more in focus than in the past decades, because it has the biggest impact on the material prices. Umicore Technical Materials has developed a new copper based HSM, CuAg40Ga10. The wettability on stainless steel is significantly improved compared to AgCu28 and the total silver content is reduced by almost 44%. In this article the physical properties of the alloy and its brazed joints will be presented compared to AgCu28.

Antimicrobial Active Clothes Display No Adverse Effects on the Ecological Balance of the Healthy Human Skin Microflora

PubMed Central

Hoefer, Dirk; Hammer, Timo R.

2011-01-01

The progressive public use of antimicrobial clothes has raised issues concerning skin health. A placebo-controlled side-to-side study was run with antimicrobial clothes versus fabrics of similar structure but minus the antimicrobial activity, to evaluate possible adverse effects on the healthy skin microflora. Sixty volunteers were enrolled. Each participant received a set of form-fitting T-shirts constructed in 2 halves: an antibacterial half, displaying activities of 3–5 log-step reductions due to silver-finishes or silver-loaded fibres and a nonantibacterial control side. The microflora of the scapular skin was analyzed weekly for opportunistic and pathogenic microorganisms over six weeks. The antibacterial halves did not disturb the microflora in number or composition, whereas a silver-containing deodorant displayed a short-term disturbance. Furthermore, parameters of skin morphology and function (TEWL, pH, moisture) did not show any significant shifts. In summary, antimicrobial clothes did not show adverse effects on the ecological balance of the healthy skin microflora. PMID:22363849

Controlling Corrosion in Defence Equipment - Technical Meeting,

DTIC Science & Technology

1985-10-01

methods identify elements. (c) IR absorption spectroscopy. % e The identifies radicals, sometimes compounds. X-ray fluorescence and atomic absorption ...components from this radio. There were 100 sets all with defective - silver plating, with a total value of $5 million. A method of refurbishment was...Assemblies from the FiiC Aircraft Slides of a corroded heat exchanger assembly were shown. A method of refurbishment was suggested. Estimated saving - $0.5

Progress in electrochemical storage for battery systems

NASA Technical Reports Server (NTRS)

Ford, F. E.; Hennigan, T. J.; Palandati, C. F.; Cohn, E.

1972-01-01

Efforts to improve electrochemical systems for space use relate to: (1) improvement of conventional systems; (2) development of fuel cells to practical power systems; and (3) a search for new systems that provide gains in energy density but offer comparable life and performance as conventional systems. Improvements in sealed conventional systems resulted in the areas of materials, charge control methods, cell operations and battery control, and specific process controls required during cell manufacture. Fuel-cell systems have been developed for spacecraft but the use of these power plants is limited. For present and planned flights, nickel-cadmium, silver-zinc, and silver-cadmium systems will be used. Improvements in nickel-cadmium batteries have been applied in medical and commercial areas.

The Development of K-8 Progress Monitoring Measures in Mathematics for Use with the 2% and General Education Populations: Kindergarten. Technical Report # 0921

ERIC Educational Resources Information Center

Alonzo, Julie; Tindal, Gerald

2009-01-01

In this technical report, we describe the development and piloting of a series of mathematics progress monitoring measures intended for use with students in kindergarten. These measures, available as part of easyCBM[TM], an online progress monitoring assessment system, were developed in 2008 and administered to approximately 2800 students from…

Glucose capped silver nanoparticles induce cell cycle arrest in HeLa cells.

PubMed

Panzarini, Elisa; Mariano, Stefania; Vergallo, Cristian; Carata, Elisabetta; Fimia, Gian Maria; Mura, Francesco; Rossi, Marco; Vergaro, Viviana; Ciccarella, Giuseppe; Corazzari, Marco; Dini, Luciana

2017-06-01

This study aims to determine the interaction (uptake and biological effects on cell viability and cell cycle progression) of glucose capped silver nanoparticles (AgNPs-G) on human epithelioid cervix carcinoma (HeLa) cells, in relation to amount, 2×10 3 or 2×10 4 NPs/cell, and exposure time, up to 48h. The spherical and well dispersed AgNPs (30±5nm) were obtained by using glucose as reducing agent in a green synthesis method that ensures to stabilize AgNPs avoiding cytotoxic soluble silver ions Ag + release. HeLa cells take up abundantly and rapidly AgNPs-G resulting toxic to cells in amount and incubation time dependent manner. HeLa cells were arrested at S and G2/M phases of the cell cycle and subG1 population increased when incubated with 2×10 4 AgNPs-G/cell. Mitotic index decreased accordingly. The dissolution experiments demonstrated that the observed effects were due only to AgNPs-G since glucose capping prevents Ag + release. The AgNPs-G influence on HeLa cells viability and cell cycle progression suggest that AgNPs-G, alone or in combination with chemotherapeutics, may be exploited for the development of novel antiproliferative treatment in cancer therapy. However, the possible influence of the cell cycle on cellular uptake of AgNPs-G and the mechanism of AgNPs entry in cells need further investigation. Copyright © 2017 Elsevier B.V. All rights reserved.

Assessment Program Technical Progress Report, 1996-1997.

ERIC Educational Resources Information Center

McCown, Laurie; Fanning, Erin; Eickmeyer, Barbara

Coconino Community College (CCC) annually assesses its institutional effectiveness to demonstrate its commitment to improving programs and services to students. The 1996-97 Assessment Program Technical Progress Report records the assessment and institutional activities enacted during the academic year, detailing the assessment model, timelines,…

The Development of K-8 Progress Monitoring Measures in Mathematics for Use with the 2% and General Education Populations: Grade 1. Technical Report # 0919

ERIC Educational Resources Information Center

Alonzo, Julie; Tindal, Gerald

2009-01-01

In this technical report, we describe the development and piloting of a series of mathematics progress monitoring measures intended for use with students in grade 1. These measures, available as part of easyCBM [TM], an online progress monitoring assessment system, were developed in 2008 and administered to approximately 2800 students from schools…

The Development of K-8 Progress Monitoring Measures in Mathematics for Use with the 2% and General Education Populations: Grade 3. Technical Report # 09-02

ERIC Educational Resources Information Center

Alonzo, Julie; Lai, Cheng Fei; Tindal, Gerald

2009-01-01

In this technical report, we describe the development and piloting of a series of mathematics progress monitoring measures intended for use with students in grades kindergarten through eighth grade. These measures, available as part of easyCBM[TM], an online progress monitoring assessment system, were developed in 2007 and 2008 and administered to…

The Development of K-8 Progress Monitoring Measures in Mathematics for Use with the 2% and General Education Populations: Grade 2. Technical Report # 0920

ERIC Educational Resources Information Center

Alonzo, Julie; Lai, Cheng Fei; Tindal, Gerald

2009-01-01

In this technical report, we describe the development and piloting of a series of mathematics progress monitoring measures intended for use with students in grades kindergarten through eighth grade. These measures, available as part of easyCBM[TM], an online progress monitoring assessment system, were developed in 2007 and 2008 and administered to…

The Development of K-8 Progress Monitoring Measures in Mathematics for Use with the 2% and General Education Populations: Grade 5. Technical Report # 09-01

ERIC Educational Resources Information Center

Lai, Cheng Fei; Alonzo, Julie; Tindal, Gerald

2009-01-01

In this technical report, we describe the development and piloting of a series of mathematics progress monitoring measures intended for use with students in grades kindergarten through eighth grade. These measures, available as part of easyCBM[TM], an online progress monitoring assessment system, were developed in 2007 and 2008 and administered to…

The Development of K-8 Progress Monitoring Measures in Mathematics for Use with the 2% and General Education Populations: Grade 4. Technical Report # 09-03

ERIC Educational Resources Information Center

Alonzo, Julie; Lai, Cheng Fei; Tindal, Gerald

2009-01-01

In this technical report, we describe the development and piloting of a series of mathematics progress monitoring measures intended for use with students in grades kindergarten through eighth grade. These measures, available as part of easyCBM[TM], an online progress monitoring assessment system, were developed in 2007 and 2008 and administered to…

The Development of K-8 Progress Monitoring Measures in Mathematics for Use with the 2% and General Education Populations: Grade 7. Technical Report 0908

ERIC Educational Resources Information Center

Lai, Cheng Fei; Alonzo, Julie; Tindal, Gerald

2009-01-01

In this technical report, we describe the development and piloting of a series of mathematics progress monitoring measures intended for use with students in grades kindergarten through eighth grade. These measures, available as part of easyCBM[TM], an online progress monitoring assessment system, were developed in 2007 and 2008 and administered to…

The Development of K-8 Progress Monitoring Measures in Mathematics for Use with the 2% and General Education Populations: Grade 8. Technical Report # 09-04

ERIC Educational Resources Information Center

Lai, Cheng Fei; Alonzo, Julie; Tindal, Gerald

2009-01-01

In this technical report, we describe the development and piloting of a series of mathematics progress monitoring measures intended for use with students in grades kindergarten through eighth grade. These measures, available as part of easyCBM[TM], an online progress monitoring assessment system, were developed in 2007 and 2008 and administered to…

Relationship between interphasic nucleolar organizer regions and growth rate in two neuroblastoma cell lines.

PubMed Central

Derenzini, M.; Pession, A.; Farabegoli, F.; Trerè, D.; Badiali, M.; Dehan, P.

1989-01-01

The relationship between the quantity of silver-stained interphasic nucleolar organizer regions (NORs) and nuclear synthetic activity, caryotype, and growth rate was studied in two established neuroblastoma cell lines (CHP 212 and HTB 10). Statistical analysis of silver-stained NORs revealed four times as many in CHP 212 cells compared with HTB 10 cells. No difference was observed in the ribosomal RNA synthesis between the two cell lines. The caryotype index was 1.2 for CHP 212 and 1.0 for HTB 10 cells. The number of chromosomes carrying NORs and the quantity of ribosomal genes was found to be the same for the two cell lines. Doubling time of CHP 212 cells was 20 hours compared with 54 hours for HTB 10 cells. In CHP 212 cells bindering of cell duplication by serum deprivation induced a progressive lowering (calculated at 48, 72, and 96 hours) of the quantity of silver-stained interphasic NORs. Recovery of duplication by new serum addition induced, after 24 hours, an increase of the quantity of silver-stained interphasic NORs up to control levels. In the light of available data, these results indicate that the quantity of interphasic NORs is strictly correlated only to the growth rate of the cell. Images Figure 2 Figure 3 Figure 4 PMID:2705511

Phytotoxicity, accumulation and transport of silver nanoparticles by Arabidopsis thaliana.

PubMed

Geisler-Lee, Jane; Wang, Qiang; Yao, Ying; Zhang, Wen; Geisler, Matt; Li, Kungang; Huang, Ying; Chen, Yongsheng; Kolmakov, Andrei; Ma, Xingmao

2013-05-01

The widespread availability of nano-enabled products in the global market may lead to the release of a substantial amount of engineered nanoparticles in the environment, which frequently display drastically different physiochemical properties than their bulk counterparts. The purpose of the study was to evaluate the impact of citrate-stabilised silver nanoparticles (AgNPs) on the plant Arabidopsis thaliana at three levels, physiological phytotoxicity, cellular accumulation and subcellular transport of AgNPs. The monodisperse AgNPs of three different sizes (20, 40 and 80 nm) aggregated into much larger sizes after mixing with quarter-strength Hoagland solution and became polydisperse. Immersion in AgNP suspension inhibited seedling root elongation and demonstrated a linear dose-response relationship within the tested concentration range. The phytotoxic effect of AgNPs could not be fully explained by the released silver ions. Plants exposed to AgNP suspensions bioaccumulated higher silver content than plants exposed to AgNO3 solutions (Ag(+) representative), indicating AgNP uptake by plants. AgNP toxicity was size and concentration dependent. AgNPs accumulated progressively in this sequence: border cells, root cap, columella and columella initials. AgNPs were apoplastically transported in the cell wall and found aggregated at plasmodesmata. In all the three levels studied, AgNP impacts differed from equivalent dosages of AgNO3.

Multifunctional inulin tethered silver-graphene quantum dots nanotheranostic module for pancreatic cancer therapy.

PubMed

Nigam Joshi, Preeti; Agawane, Sachin; Athalye, Meghana C; Jadhav, Vrushali; Sarkar, Dhiman; Prakash, Rajiv

2017-09-01

Cancer nanotechnology is an emerging area of cancer diagnosis and therapy. Although considerable progress has been made for targeted drug delivery systems to deliver anticancer agents to particular site of interest, new nanomaterials are frequently being developed and explored for better drug delivery efficiency. In the present work, we have explored a novel nanoformulation based on silver-graphene quantum dots (Ag-GQDs) nanocomposite for its successful implementation for pancreatic cancer specific drug delivery in wistar rats. Carboxymethyl inulin (CMI); a modified variant of natural polysaccharide inulin is tethered with the nanocomposite via carbodiimide coupling to enhance the biocompatibility of nanoformulation. Experiments are performed to investigate the cytotoxicity reduction of silver nanoparticles after inulin tethering as well as anticancer efficacy of the system using 5-Fluorouracil (5-FU) as model drug. SEM, TEM, FT-IR, UV-vis, photoluminescence and anti proliferative assays (MTT) are performed for characterisation of the nanocomposite. Hyaluronic acid (HA) is conjugated as targeting moiety for CD-44 (cancer stem cell marker) to fabricate a complete targeted drug delivery vehicle specific for pancreatic cancer. In the present work two prime objectives were achieved; mitigation the toxicity of silver nanoparticles by inulin coating and it's in vivo application for pancreatic cancer. Copyright © 2017 Elsevier B.V. All rights reserved.

Designs for Progress in Science Education.

ERIC Educational Resources Information Center

Butts, David P.

This book, prepared as a part of the activities of the National Science Teachers Association (NSTA) Silver Anniversary Year, is directed at setting forth designs for the future of science education which will benefit as equally as possible those who see science as a life-long intellectual adventure and occupation, those who commit themselves to…

Development and Validation of a Novel Scoring System for Predicting Technical Success of Chronic Total Occlusion Percutaneous Coronary Interventions: The PROGRESS CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention) Score.

PubMed

Christopoulos, Georgios; Kandzari, David E; Yeh, Robert W; Jaffer, Farouc A; Karmpaliotis, Dimitri; Wyman, Michael R; Alaswad, Khaldoon; Lombardi, William; Grantham, J Aaron; Moses, Jeffrey; Christakopoulos, Georgios; Tarar, Muhammad Nauman J; Rangan, Bavana V; Lembo, Nicholas; Garcia, Santiago; Cipher, Daisha; Thompson, Craig A; Banerjee, Subhash; Brilakis, Emmanouil S

2016-01-11

This study sought to develop a novel parsimonious score for predicting technical success of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) performed using the hybrid approach. Predicting technical success of CTO PCI can facilitate clinical decision making and procedural planning. We analyzed clinical and angiographic parameters from 781 CTO PCIs included in PROGRESS CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention) using a derivation and validation cohort (2:1 sampling ratio). Variables with strong association with technical success in multivariable analysis were assigned 1 point, and a 4-point score was developed from summing all points. The PROGRESS CTO score was subsequently compared with the J-CTO (Multicenter Chronic Total Occlusion Registry in Japan) score in the validation cohort. Technical success was 92.9%. On multivariable analysis, factors associated with technical success included proximal cap ambiguity (beta coefficient [b] = 0.88), moderate/severe tortuosity (b = 1.18), circumflex artery CTO (b = 0.99), and absence of "interventional" collaterals (b = 0.88). The resulting score demonstrated good calibration and discriminatory capacity in the derivation (Hosmer-Lemeshow chi-square = 2.633; p = 0.268, and receiver-operator characteristic [ROC] area = 0.778) and validation (Hosmer-Lemeshow chi-square = 5.333; p = 0.070, and ROC area = 0.720) subset. In the validation cohort, the PROGRESS CTO and J-CTO scores performed similarly in predicting technical success (ROC area 0.720 vs. 0.746, area under the curve difference = 0.026, 95% confidence interval = -0.093 to 0.144). The PROGRESS CTO score is a novel useful tool for estimating technical success in CTO PCI performed using the hybrid approach. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Environmental Planning Technical Report. Biological Resources

DTIC Science & Technology

1984-01-01

8217 v rini ana va r. Chokecherry melanoca rpa Shrubs Artemisia cana Silver sagebrush Ceratoides l-anata Wi nterf at Cerocarpus mortanus Mountain nahogany...nocarpa Chokecherry ialTix Spp. Wifllo 2-10 Table 2.6.1-i Continued, page 5 of 6 DOMINANT AND CHARACTERISTIC PLANT SPECIES Shrubs Salix spp. Willow...population on the Goshen Hole Rim near Flight S. Some of the more mesic draws support golden currant (Ribes aureum) and chokecherry (Prunus

Developing a Model for Predicting Snowpack Parameters Affecting Vehicle Mobility,

DTIC Science & Technology

1983-05-01

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

Final report : for the period of December 1999 through November 30, 2000 : Florida Transit Training Program (1999/2000) : Florida Technical Assistance Program (1999/2000)

DOT National Transportation Integrated Search

2000-01-01

The following progress report is intended to highlight the significant activities of the Florida Transit Training Program and Florida Technical Assistant Program. The following progress report is intended to highlight the significant activities of th...

Annual progress report : for the period of January 2001 through December 2001 : Florida Transit Training Program (2001) : Florida Technical Assistance Program (2001)

DOT National Transportation Integrated Search

2001-01-01

The following progress report is intended to highlight the significant activities of the Florida Transit Training Program and Florida Technical Assistant Program for the 2001 year. Activities of the Florida Statewide Transit Training Program are pres...

76 FR 64083 - Reliability Technical Conference; Notice of Technical Conference

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-17

... Technical Conference; Notice of Technical Conference Take notice that the Federal Energy Regulatory Commission will hold a Technical Conference on Tuesday, November 29, 2011, from 1 p.m. to 5 p.m. and... System. The conference will explore the progress made on the priorities for addressing risks to...

48 CFR 2052.211-70 - Preparation of technical reports.

Code of Federal Regulations, 2014 CFR

2014-10-01

....211-70 Preparation of technical reports. As prescribed at 2011.104-70(a), the contracting officer... Reports (JAN 1993) All technical reports required by Section C and all Technical Progress Reports required... 48 Federal Acquisition Regulations System 6 2014-10-01 2014-10-01 false Preparation of technical...

48 CFR 2052.211-70 - Preparation of technical reports.

Code of Federal Regulations, 2012 CFR

2012-10-01

....211-70 Preparation of technical reports. As prescribed at 2011.104-70(a), the contracting officer... Reports (JAN 1993) All technical reports required by Section C and all Technical Progress Reports required... 48 Federal Acquisition Regulations System 6 2012-10-01 2012-10-01 false Preparation of technical...

48 CFR 2052.211-70 - Preparation of technical reports.

Code of Federal Regulations, 2010 CFR

2010-10-01

....211-70 Preparation of technical reports. As prescribed at 2011.104-70(a), the contracting officer... Reports (JAN 1993) All technical reports required by Section C and all Technical Progress Reports required... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Preparation of technical...

48 CFR 2052.211-70 - Preparation of technical reports.

Code of Federal Regulations, 2013 CFR

2013-10-01

....211-70 Preparation of technical reports. As prescribed at 2011.104-70(a), the contracting officer... Reports (JAN 1993) All technical reports required by Section C and all Technical Progress Reports required... 48 Federal Acquisition Regulations System 6 2013-10-01 2013-10-01 false Preparation of technical...

48 CFR 2052.211-70 - Preparation of technical reports.

Code of Federal Regulations, 2011 CFR

2011-10-01

....211-70 Preparation of technical reports. As prescribed at 2011.104-70(a), the contracting officer... Reports (JAN 1993) All technical reports required by Section C and all Technical Progress Reports required... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false Preparation of technical...

REACTOR PHYSICS QUARTERLY REPORT JANUARY, FEBRUARY, MARCH 1970

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

Schmid, L. C.; Clayton, E. D.; Heineman, R. E.

1970-05-01

The objective of the Reactor Physics Quarterly Report is to inform the scientific community in a timely manner of the technical progress made on the many phases of reactor physics work within the laboratory. The report contains brief technical discussions of accomplishments in all areas where significant progress has been made during the quarter.

George A. Olah, Carbocation and Hydrocarbon Chemistry

Science.gov Websites

. Final Technical Report. [HF:BF{sub 2}/H{sub 2}] , DOE Technical Report, 1980 Superacid Catalyzed Coal Conversion Chemistry. 1st and 2nd Quarterly Technical Progress Reports, September 1, 1983-March 30, 1984 , DOE Technical Report, 1984 Superacid Catalyzed Coal Conversion Chemistry. Final Technical Report

HKHC Community Dashboard: design, development, and function of a Web-based performance monitoring system.

PubMed

Bors, Philip A; Kemner, Allison; Fulton, John; Stachecki, Jessica; Brennan, Laura K

2015-01-01

As part of Robert Wood Johnson Foundation's Healthy Kids, Healthy Communities (HKHC) national grant program, a technical assistance team designed the HKHC Community Dashboard, an online progress documentation and networking system. The Dashboard was central to HKHC's multimethod program evaluation and became a communication interface for grantees and technical assistance providers. The Dashboard was designed through an iterative process of identifying needs and priorities; designing the user experience, technical development, and usability testing; and applying visual design. The system was created with an open-source content management system and support for building an online community of users. The site developer trained technical assistance providers at the national program office and evaluators, who subsequently trained all 49 grantees. Evaluators provided support for Dashboard users and populated the site with the bulk of its uploaded tools and resource documents. The system tracked progress through an interactive work plan template, regular documentation by local staff and partners, and data coding and analysis by the evaluation team. Other features included the ability to broadcast information to Dashboard users via e-mail, event calendars, discussion forums, private messaging, a resource clearinghouse, a technical assistance diary, and real-time progress reports. The average number of Dashboard posts was 694 per grantee during the grant period. Technical assistance providers and grantees uploaded a total of 1304 resource documents. The Dashboard functions with the highest grantee satisfaction were its interfaces for sharing and progress documentation. A majority of Dashboard users (69%) indicated a preference for continued access to the Dashboard's uploaded resource documents. The Dashboard was a useful and innovative tool for participatory evaluation of a large national grant program. While progress documentation added some burden to local project staff, the system proved to be a useful resource-sharing technology.

Progress In The Commercialization Of A Carbonaceous Solar Selective Absorber On A Glass Substrate

NASA Astrophysics Data System (ADS)

Garrison, John D.; Haiad, J. Carlos; Averett, Anthony J.

1987-11-01

A carbonaceous solar selective absorber is formed on a glass substrate by coating the glass with a silver infrared reflecting layer, electroplating a thin nickel catalyst coating on the silver using very special plating conditions, and then exposing the nickel coated, silvered glass substrate to acetylene at a temperature of about 400 - 500°C for about five minutes. A fairly large plater and conveyor oven have been constructed and operated for the formation of these solar selective absorbers in order to study the formation of this absorber by a process which might be used commercially. Samples of this selective absorber on a glass substrate have been formed using the plater and conveyor oven. The samples, which have the best optical properties, have an absorptance of about 0.9 and an emittance of about 0.03. Excessive decomposition of the acetylene by the walls of the oven at higher temperatures with certain wall materials and oven geometries can prevent the formation of good selective absorbers. Procedures for preventing excessive decomposition of the acetylene and the knowledge gained so far by these studies is discussed.

Modeling the impacts of climate change and technical progress on the wheat yield in inland China: An autoregressive distributed lag approach.

PubMed

Zhai, Shiyan; Song, Genxin; Qin, Yaochen; Ye, Xinyue; Lee, Jay

2017-01-01

This study aims to evaluate the impacts of climate change and technical progress on the wheat yield per unit area from 1970 to 2014 in Henan, the largest agricultural province in China, using an autoregressive distributed lag approach. The bounded F-test for cointegration among the model variables yielded evidence of a long-run relationship among climate change, technical progress, and the wheat yield per unit area. In the long run, agricultural machinery and fertilizer use both had significantly positive impacts on the per unit area wheat yield. A 1% increase in the aggregate quantity of fertilizer use increased the wheat yield by 0.19%. Additionally, a 1% increase in machine use increased the wheat yield by 0.21%. In contrast, precipitation during the wheat growth period (from emergence to maturity, consisting of the period from last October to June) led to a decrease in the wheat yield per unit area. In the short run, the coefficient of the aggregate quantity of fertilizer used was negative. Land size had a significantly positive impact on the per unit area wheat yield in the short run. There was no significant short-run or long-run impact of temperature on the wheat yield per unit area in Henan Province. The results of our analysis suggest that climate change had a weak impact on the wheat yield, while technical progress played an important role in increasing the wheat yield per unit area. The results of this study have implications for national and local agriculture policies under climate change. To design well-targeted agriculture adaptation policies for the future and to reduce the adverse effects of climate change on the wheat yield, climate change and technical progress factors should be considered simultaneously. In addition, adaptive measures associated with technical progress should be given more attention.

Modeling the impacts of climate change and technical progress on the wheat yield in inland China: An autoregressive distributed lag approach

PubMed Central

Qin, Yaochen; Lee, Jay

2017-01-01

This study aims to evaluate the impacts of climate change and technical progress on the wheat yield per unit area from 1970 to 2014 in Henan, the largest agricultural province in China, using an autoregressive distributed lag approach. The bounded F-test for cointegration among the model variables yielded evidence of a long-run relationship among climate change, technical progress, and the wheat yield per unit area. In the long run, agricultural machinery and fertilizer use both had significantly positive impacts on the per unit area wheat yield. A 1% increase in the aggregate quantity of fertilizer use increased the wheat yield by 0.19%. Additionally, a 1% increase in machine use increased the wheat yield by 0.21%. In contrast, precipitation during the wheat growth period (from emergence to maturity, consisting of the period from last October to June) led to a decrease in the wheat yield per unit area. In the short run, the coefficient of the aggregate quantity of fertilizer used was negative. Land size had a significantly positive impact on the per unit area wheat yield in the short run. There was no significant short-run or long-run impact of temperature on the wheat yield per unit area in Henan Province. The results of our analysis suggest that climate change had a weak impact on the wheat yield, while technical progress played an important role in increasing the wheat yield per unit area. The results of this study have implications for national and local agriculture policies under climate change. To design well-targeted agriculture adaptation policies for the future and to reduce the adverse effects of climate change on the wheat yield, climate change and technical progress factors should be considered simultaneously. In addition, adaptive measures associated with technical progress should be given more attention. PMID:28950027

Supply Chain Sustainability Analysis of Whole Algae Hydrothermal Liquefaction and Upgrading

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

Pegallapati, Ambica Koushik; Dunn, Jennifer B.; Frank, Edward D.

2015-04-01

The Department of Energy's Bioenergy Technology Office (BETO) collaborates with a wide range of institutions towards the development and deployment of biofuels and bioproducts. To facilitate this effort, BETO and its partner national laboratories develop detailed techno-economic assessments (TEA) of biofuel production technologies as part of the development of design cases and state of technology (SOT) analyses. A design case is a TEA that outlines a target case for a particular biofuel pathway. It enables preliminary identification of data gaps and research and development needs and provides goals and targets against which technology progress is assessed. On the other hand,more » an SOT analysis assesses progress within and across relevant technology areas based on actual experimental results relative to technical targets and cost goals from design cases and includes technical, economic, and environmental criteria as available. (SOT) analyses. A design case is a TEA that outlines a target case for a particular biofuel pathway. It enables preliminary identification of data gaps and research and development needs and provides goals and targets against which technology progress is assessed. On the other hand, an SOT analysis assesses progress within and across relevant technology areas based on actual experimental results relative to technical targets and cost goals from design cases and includes technical, economic, and environmental criteria as available. (SOT) analyses. A design case is a TEA that outlines a target case for a particular biofuel pathway. It enables preliminary identification of data gaps and research and development needs and provides goals and targets against which technology progress is assessed. On the other hand, an SOT analysis assesses progress within and across relevant technology areas based on actual experimental results relative to technical targets and cost goals from design cases and includes technical, economic, and environmental criteria as available.« less

Silver and tin plating as medieval techniques of producing counterfeit coins and their identification by means of micro-XRF

NASA Astrophysics Data System (ADS)

Hložek, M.; Trojek, T.

2017-08-01

Archaeological surveys and metal detector prospecting yield a great amount of coins from the medieval period. Naturally, some of these are counterfeit which an experienced numismatist can determine without using chemical methods. The production of counterfeit coins in the middle ages took place in castles, caves or other remote areas where waste from this activity can still be found today - copper sheets, technical ceramics and counterfeit coins. Until recently, it has been assumed that medieval counterfeit coins are made by silver-plating copper blanks using an amalgam. However, the performed analyses reveal that there are many more techniques of counterfeiting of coins. Other techniques were based on e.g. tin amalgam plating of the blanks or alloying so-called white metal with silver-like appearance from which the coins were minted. Current chemical analyses indicate that the coins were often tinned by hot dipping with no amalgamation. Micro-X-ray fluorescence analysis has been chosen as a suitable non-destructive method to identify present chemical elements in investigated artifacts and to quantify their concentrations. In addition, a quick technique telltale the plating was applied. This technique utilizes the detected fluorescence ratio Kα/Kβ of copper, which is the main ingredient of a lot of historical metallic materials.

Conductive pathway on cotton fabric created using solution with silver organometallic compound

NASA Astrophysics Data System (ADS)

Campbell, Eric E.; He, Ruijian; Mayer, Michael

2017-10-01

A knitted cotton fabric is made conductive by thermal deposition of an organometallic silver compound (OSC). For the thermal process, the fabric was soaked with the OSC liquid and heated to 225 °C for 4 min. The cured state of the OSC is determined by the stabilization in the electrical resistance. The resulting silver metallization is shaped as nanoparticles and a continuous film. A typical resistance of a 10 cm  ×  1.5 cm metallized strip made with 1.9 ml OSC is 1.70 Ω. Various other resistance levels were achieved. A higher volume of OSC provided a lower electrical resistance for the metallized conductive path but increased its stiffness. Lower resistance was achieved by increasing the number of repeat coatings while keeping the OSC volume constant. The resistance decreased when the OSC coated fabric was elongated, an effect similar to negative piezoresistivity. A resistance of initially 0.34 Ω decreased to a minimum of 0.29 Ω at 10% elongation under repeated stretching and relaxation cycling. The metallization method reported here can be suitable for applications in the field know as technical textiles, electronic textiles (e-textiles), wearable electronics, functional garments, or smart fabrics.

Technical Adequacy of Growth Estimates from a Computer Adaptive Test: Implications for Progress Monitoring

ERIC Educational Resources Information Center

Van Norman, Ethan R.; Nelson, Peter M.; Parker, David C.

2017-01-01

Computer adaptive tests (CATs) hold promise to monitor student progress within multitiered systems of support. However, the relationship between how long and how often data are collected and the technical adequacy of growth estimates from CATs has not been explored. Given CAT administration times, it is important to identify optimal data…

Education, Industrialization and Technical Progress in Mexico. IIEP Research Report No. 6.

ERIC Educational Resources Information Center

Padua, Jorge

This report attempts to analyze the contributions of the educational system and job training programs to industrialization and technical progress in the Conubal zone of the Lower Balsas River of Mexico. The first of the study's three sections consists of two chapters that provide general background. Chapter 1, "Theories of Development and the…

Technical Adequacy and Acceptability of Curriculum-Based Measurement and the Measures of Academic Progress

ERIC Educational Resources Information Center

January, Stacy-Ann A.; Ardoin, Scott P.

2015-01-01

Curriculum-based measurement in reading (CBM-R) and the Measures of Academic Progress (MAP) are assessment tools widely employed for universal screening in schools. Although a large body of research supports the validity of CBM-R, limited empirical evidence exists supporting the technical adequacy of MAP or the acceptability of either measure for…

Annual Technical Progress Report for Emergency School Assistance Program, Title 45, 1970-71.

ERIC Educational Resources Information Center

Lindsey, Randall B.

This paper presents a technical progress report of two programs conducted with funds provided under the Emergency School Assistance Program. One, the Mobile Learning Unit, said to have been designed to measure changes in fourth and fifth grade students' self-concept in a reorganized desegregated school environment, focuses on whether a positive…

Third Progress and Information Report of the Vocational-Technical Education Consortium of States.

ERIC Educational Resources Information Center

Lee, Connie W.; And Others

This description of major activities and accomplishments of the Vocational-Technical Education Consortium of the States (V-TECS) since the second progress report of May, 1975, is designed to provide the reader with a basic understanding of the processes and procedures used by the consortium in achieving its major goal: The production of catalogs…

A PSFI-based analysis on the energy efficiency potential of China’s domestic passenger vehicles

NASA Astrophysics Data System (ADS)

Chen, Chuan; Ren, Huanhuan; Zhao, Dongchang

2017-01-01

In this article, China’s domestic passenger vehicles (excluding new energy vehicles) are categorized into two groups: local brand vehicles and vehicles manufactured by joint ventures. Performance-Size-Fuel economy Index (PSFI) will be applied to analyse the speed of technical progress and the future trends of these vehicles. In addition, a forecast on energy efficiency potential of domestic passenger vehicles from 2016 to 2020 will be made based on different Emphasis on Reducing Fuel Consumption (ERFC) scenarios. According to the study, if the process of technical progress continues at its current speed, domestic ICE passenger vehicles will hardly meet Phase IV requirements by 2020 even though companies contribute as much technical progress to fuel consumption reduction as possible.

Advanced Thermal Emission Imaging Systems Definition and Development

NASA Technical Reports Server (NTRS)

Blasius, Karl; Nava, David (Technical Monitor)

2002-01-01

Santa Barbara Remote Sensing (SBRS), Raytheon Company, is pleased to submit this quarterly progress report of the work performed in the third quarter of Year 2 of the Advanced THEMIS Project, July through September 2002. We review here progress in the proposed tasks. During July through September 2002 progress was made in two major tasks, Spectral Response Characterization and Flight Instrument Definition. Because of staffing problems and technical problems earlier in the program we have refocused the remaining time and budget on the key technical tasks. Current technical problems with a central piece of test equipment has lead us to request a 1 quarter extension to the period of performance. This request is being made through a separate letter independent of this report.

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

Stout, D.K.

Flaws are noted in equilibrium growth models which ignore the facts that labor is no longer homogeneous, national governments can no longer guarantee a managed demand, and technical progress is not an independent force. The pace of technical progress is the major variable and increases with competition and certainty in the growth of demand. The outlook for technical progress is examined in the context of productivity, using microprocessor development for illustration. The author takes an optimistic view of new developments in that they do not bring the self-destructive possibility of overpopulation, irreversible damage to the environment, or nuclear war anymore » closer, while having a positive chance to promote a more rewarding relationship between education, work, and life style. The opportunities for positive humanistic changes through microprocessing are confirmed. (DCK)« less

Index to Nuclear Safety. A technical progress review by chronology, permuted title, and author. Vol. 11, No. 1--Vol. 17, No. 6

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

Cottrell, W.B.; Klein, A.

1977-02-23

This index to Nuclear Safety covers articles in Nuclear Safety Vol. 11, No. 1 (Jan.-Feb. 1970), through Vol. 17, No. 6 (Nov.-Dec. 1976). The index includes a chronological list of articles (including abstract) followed by KWIC and Author Indexes. Nuclear Safety, a bimonthly technical progress review prepared by the Nuclear Safety Information Center, covers all safety aspects of nuclear power reactors and associated facilities. The index lists over 350 technical articles in the last six years of publication.

Two Dimensional Compressibility of Electrochemically Adsorbed Lead on Silver (111).

DTIC Science & Technology

1988-01-28

PAGE BEFORE COMPLETING FORM REPOR7 4 MS1 2. GOVT ACCESSION NO1 3. RECIPIET’S CATALOG NUMBER Technical Reserach -32C E " :. :)S. TYPE OP REPORT & PERIOD...considerably more difficult, since two 2 dimensional band structure calculations that include the effect of the substrate are necessary. In this paper , we...bulk lead. No additional change in the spacing is observed with potential beyond the the onset of bulk lead deposition. It should be recognized that ,he

Single crystals of metal solid solutions

NASA Technical Reports Server (NTRS)

Miller, J. F.; Austin, A. E.; Richard, N.; Griesenauer, N. M.; Moak, D. P.; Mehrabian, M. R.; Gelles, S. H.

1974-01-01

The following definitions were sought in the research on single crystals of metal solid solutions: (1) the influence of convection and/or gravity present during crystallization on the substructure of a metal solid solution; (2) the influence of a magnetic field applied during crystallization on the substructure of a metal solid solution; and (3) requirements for a space flight experiment to verify the results. Growth conditions for the selected silver-zinc alloy system are described, along with pertinent technical and experimental details of the project.

The National Nanotechnology Initiative. Research and Development Leading to a Revolution in Technology ad Industry. Supplement to the President’s 2009 Budget

DTIC Science & Technology

2008-09-30

About this document This document is a supplement to the President’s 2009 Budget Request submitted to Congress on February 4, 2008. It gives a ...Initiative (NNI), primarily from a programmatic and budgetary perspective. It is based on the NNI Strategic Plan released in December 2007 and reports...microscope image of C60 molecules on a flat silver surface. Additional technical and ordering information for the new NIST nanoparticle reference

The Anomalous Metalloporphyrin and Chlorophyll a Activated Chemiluminescence of Dimethyldioxetanone. Chemically Initiated Electron-Exchange Luminescence.

DTIC Science & Technology

1980-02-26

cadmium, and magnesium porphyrins the first oxidation is ligand centered. 7 On the other hand, for silver and cobalt porphyrin the first oxidation...kQ . Cyclic voltammetry was done in argon saturated dichlor- omethane solution at (23±2)°C with 0.1 M tetra-n-butyl-ammonium perchlorate as supporting...TECHNICAL REPORT DISTRIBUTION LIST. 051A No. No. Copies Cpe Dr. M. A. El-Sayed Dr. ItI. Rauhut Department of Chemistry Chemical Research Division University

[Potentiometric concentration determination of cyanide ions in waste water].

PubMed

Börner, J; Martin, G; Götz, C

1990-06-01

Electrodic systems, consist of gold or silver and metals of the IV, or V, subsidiary groups of the periodic system of elements are qualified for that, because they based strength of their electrodic steepness, selectivity, potentionel stability and sensibility by destination of cyanid ions in waste-water. We are going to introduce a fast-analysis-method for cyanid ions in waste-water of technical processes, which had been tested practically by the continuous control of limits, demanded by the legislator.

[Address Given at the Regional Junior College Recreation Education Institute, American River College, September 25, 1969.

ERIC Educational Resources Information Center

Lutzin, Sidney G.

The United States has made striking technical advances in recent years, but there has not been comparable progress in social services. Greater affluence and leisure for some have been one result of technical progress, but problems of poverty and urban development are more pressing. New developments to improve the condition of society can be…

THE DEVELOPMENT OF PRE-VOCATIONAL EDUCATION LITERACY COURSES FOR USE WITH COMPUTER ASSISTED INSTRUCTION OF DISADVANTAGED YOUTH AND ADULTS. TECHNICAL PROGRESS REPORT.

ERIC Educational Resources Information Center

HANKIN, EDWARD K.; AND OTHERS

THIS TECHNICAL PROGRESS REPORT COVERS THE FIRST THREE MONTHS OF A PROJECT TO DEVELOP COMPUTER ASSISTED PREVOCATIONAL READING AND ARITHMETIC COURSES FOR DISADVANTAGED YOUTHS AND ADULTS. DURING THE FIRST MONTH OF OPERATION, PROJECT PERSONNEL CONCENTRATED ON SUCH ADMINISTRATIVE MATTERS AS TRAINING STAFF AND PREPARING FACILITIES. AN ARITHMETIC PROGRAM…

Generation and focusing of pulsed intense ion beams. Technical progress report, 20 August 1981-30 September 1982

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

Hammer, D.A.; Kusse, B.R.; Sudan, R.N.

1983-07-01

The progress on this contract is described in two parts. The first deals with the technical operation of the LION accelerator which is the exact equivalent to one line of PBFA-I. The second part is concerned with the experimental results on the ion diode mounted at the front end of the LION accelerator.

Project LIFE--Language Improvement to Facilitate Education. (Technical Progress Report; Third Quarter; March 1, 1974-May 31, 1974).

ERIC Educational Resources Information Center

National Foundation for the Improvement of Education, Washington, DC.

Reported is the third quarter, fiscal year 1974 (March 1, 1974-May 31, 1974) technical progress of Project LIFE (Language Improvement to Facilitate Education), toward developing an instructional system in which filmstrips in the areas of perceptual training, perceptual thinking, and language/reading are used to assist hearing impaired children in…

Solvent-assisted in situ synthesis of cysteamine-capped silver nanoparticles

NASA Astrophysics Data System (ADS)

Oliva, José M.; Ríos de la Rosa, Julio M.; Sayagués, María J.; Sánchez-Alcázar, José A.; Merkling, Patrick J.; Zaderenko, Ana P.

2018-03-01

Silver nanoparticles offer a huge potential for biomedical applications owing to their exceptional properties and small size. Specifically, cysteamine-capped silver nanoparticles could form the basis for new anticancer therapies combining the cytotoxic effect of the silver core with the inherent antitumor activity of cysteamine, which inhibit cancer cell proliferation and suppress invasion and metastasis. In addition, the capability of the cysteamine coating monolayer to couple a variety of active principles and targeting (bio)molecules of interest proves key to the tailoring of this platform in order to exploit the pathophysiology of specific tumor types. Nevertheless, the chain length and conformational flexibility of cysteamine, together with its ability to attach to the surface of silver nanoparticles via both the thiol and the amine group, have made the in situ synthesis of these particles an especially challenging task. Herein we report a solvent-assisted in situ synthesis method that solves this problem. The obtained nanoparticles have been fully characterized by UV-visible absorption spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, electron diffraction measurement, high resolution transmission electron microscopy, scanning transmission electron microscopy, energy dispersive x-ray spectroscopy nanoanalysis, and dynamic light scattering measurement. Our synthesis method achieves extremely high yield and surface coating ratio, and colloidal stability over a wide range of pH values including physiological pH. Additionally, we have demonstrated that cysteamine-capped nanoparticles obtained by this method can be conjugated to an antibody for active targeting of the epidermal growth factor receptor, which plays an important role in the pathogenesis and progression of a wide variety of tumors, and induce cell death in human squamous carcinoma cells. We believe this method can be readily extended to combinations of noble metals and longer chain primary, secondary, ternary or even quaternary aminethiols.

Silver diagnosis in neuropathology: principles, practice and revised interpretation

PubMed Central

2007-01-01

Silver-staining methods are helpful for histological identification of pathological deposits. In spite of some ambiguities regarding their mechanism and interpretation, they are widely used for histopathological diagnosis. In this review, four major silver-staining methods, modified Bielschowsky, Bodian, Gallyas (GAL) and Campbell–Switzer (CS) methods, are outlined with respect to their principles, basic protocols and interpretations, thereby providing neuropathologists, technicians and neuroscientists with a common basis for comparing findings and identifying the issues that still need to be clarified. Some consider “argyrophilia” to be a homogeneous phenomenon irrespective of the lesion and the method. Thus, they seek to explain the differences among the methods by pointing to their different sensitivities in detecting lesions (quantitative difference). Comparative studies, however, have demonstrated that argyrophilia is heterogeneous and dependent not only on the method but also on the lesion (qualitative difference). Each staining method has its own lesion-dependent specificity and, within this specificity, its own sensitivity. This “method- and lesion-dependent” nature of argyrophilia enables operational sorting of disease-specific lesions based on their silver-staining profiles, which may potentially represent some disease-specific aspects. Furthermore, comparisons between immunohistochemical and biochemical data have revealed an empirical correlation between GAL+/CS-deposits and 4-repeat (4R) tau (corticobasal degeneration, progressive supranuclear palsy and argyrophilic grains) and its complementary reversal between GAL-/CS+deposits and 3-repeat (3R) tau (Pick bodies). Deposits containing both 3R and 4R tau (neurofibrillary tangles of Alzheimer type) are GAL+/CS+. Although no molecular explanations, other than these empiric correlations, are currently available, these distinctive features, especially when combined with immunohistochemistry, are useful because silver-staining methods and immunoreactions are complementary to each other. PMID:17401570

Biogenic synthesis of silver nanoparticle by using secondary metabolites from Pseudomonas aeruginosa DM1 and its anti-algal effect on Chlorella vulgaris and Chlorella pyrenoidosa.

PubMed

Kumari, Rima; Barsainya, Manjari; Singh, Devendra Pratap

2017-02-01

Biogenic synthesis of silver nanoparticles (AgNPs) using extracellular metabolites from the bacterium Pseudomonas aeruginosa DM1 offers an eco-friendly and sustainable way of metal nanoparticle synthesis. The present work highlights the biotransformation of silver nitrate solution into AgNP, mediated by extracellular secondary metabolite pyoverdine, a siderophore produced by P. aeruginosa. The bioreduction of silver ions into AgNPs by using pyoverdine was recorded in terms of Fourier transform infrared spectroscopy (FTIR) analysis and color change in the reaction mixture (AgNO 3 + pyoverdine) from pale yellow to dark brown with absorption maxima at 415 nm. The results of X-ray diffraction (XRD) analysis of AgNPs showed its crystalline face-centered cubic structure. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) pictures of AgNPs showed spherical morphology of AgNP in the range of 45-100 nm, with tendency of agglomerations. The energy-dispersive X-ray (EDX) analysis of particles provided strong signal of elemental silver with few minor peaks of other impurities. The present approach offers a unique in vitro method of metal nanoparticle synthesis by exogenously produced bacterial secondary metabolites, where direct contact between the toxic metal and biological resource material can be avoided. The biologically synthesized AgNPs are found to have anti-algal effects against two species of Chlorella (Chlorella vulgaris and Chlorella pyenoidosa), as indicated by zone of growth inhibition on algal culture plates. Further results exhibit concentration-dependent progressive inhibition of chlorophyll content in the algal cells by AgNPs, confirming the algicidal effect of AgNPs.

Sieve-based coreference resolution enhances semi-supervised learning model for chemical-induced disease relation extraction.

PubMed

Le, Hoang-Quynh; Tran, Mai-Vu; Dang, Thanh Hai; Ha, Quang-Thuy; Collier, Nigel

2016-07-01

The BioCreative V chemical-disease relation (CDR) track was proposed to accelerate the progress of text mining in facilitating integrative understanding of chemicals, diseases and their relations. In this article, we describe an extension of our system (namely UET-CAM) that participated in the BioCreative V CDR. The original UET-CAM system's performance was ranked fourth among 18 participating systems by the BioCreative CDR track committee. In the Disease Named Entity Recognition and Normalization (DNER) phase, our system employed joint inference (decoding) with a perceptron-based named entity recognizer (NER) and a back-off model with Semantic Supervised Indexing and Skip-gram for named entity normalization. In the chemical-induced disease (CID) relation extraction phase, we proposed a pipeline that includes a coreference resolution module and a Support Vector Machine relation extraction model. The former module utilized a multi-pass sieve to extend entity recall. In this article, the UET-CAM system was improved by adding a 'silver' CID corpus to train the prediction model. This silver standard corpus of more than 50 thousand sentences was automatically built based on the Comparative Toxicogenomics Database (CTD) database. We evaluated our method on the CDR test set. Results showed that our system could reach the state of the art performance with F1 of 82.44 for the DNER task and 58.90 for the CID task. Analysis demonstrated substantial benefits of both the multi-pass sieve coreference resolution method (F1 + 4.13%) and the silver CID corpus (F1 +7.3%).Database URL: SilverCID-The silver-standard corpus for CID relation extraction is freely online available at: https://zenodo.org/record/34530 (doi:10.5281/zenodo.34530). © The Author(s) 2016. Published by Oxford University Press.

Monitoring the Durability Performance of Concrete in Nuclear Waste Containment. Technical Progress Report No. 4

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

Ulm, Franz-Josef

2000-06-30

OAK-B135 Monitoring the Durability Performance of Concrete in Nuclear Waste Containment. Technical Progress Report No. 4. The analysis of the effect of cracks on the acceleration of the calcium leaching process of cement-based materials has been pursued. During the last period (Technical Progress Report No 3), we have introduced a modeling accounting for the high diffusivity of fractures in comparison with the weak solid material diffusivity. It has been shown through dimensional and asymptotic analysis that small fractures do not significantly accelerate the material aging process. This important result for the overall structural aging kinetics of containment structure has beenmore » developed in a paper submitted to the international journal ''Transport in Porous Media''.« less

Department of Clinical Investigation Annual Research Progress Report, Fiscal Year 1984. Volume 1,

DTIC Science & Technology

1984-10-01

on a low dosage of medication . Technical Approach: None. Progress: The placebo has not been received from the company. Since the drug company...determine the effect of high dose Ar-C intensification therapy on the -. incidence of CNS relapse. - Technical Approach: All patients with a new...Enrolled to Date: 7 Date of Periodic Review Results Objective(s): To determine the incidence of

Total Factor Productivity Growth, Technical Progress & Efficiency Change in Vietnam Coal Industry - Nonparametric Approach

NASA Astrophysics Data System (ADS)

Phuong, Vu Hung

2018-03-01

This research applies Data Envelopment Analysis (DEA) approach to analyze Total Factor Productivity (TFP) and efficiency changes in Vietnam coal mining industry from 2007 to 2013. The TFP of Vietnam coal mining companies decreased due to slow technological progress and unimproved efficiency. The decadence of technical efficiency in many enterprises proved that the coal mining industry has a large potential to increase productivity through technical efficiency improvement. Enhancing human resource training, technology and research & development investment could help the industry to improve efficiency and productivity in Vietnam coal mining industry.

Preparation of NO 2-Aged Silver-Functionalized Silica-Aerogel and Silver Mordenite Samples

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

Jordan, Jacob A.; Bruffey, Stephanie H.

2016-10-01

Reprocessing used nuclear fuel can result in the volatilization of radioactive gaseous species, including 129I, into the various process off-gas streams. In order to comply with US regulatory requirements, plant off-gas streams must be treated to remove the iodine prior to discharging the off-gas into the environment. The performance of available gas removal methods depends not only on the concentration of the volatile radioisotope of interest, but also on other constituents that could be present in the reprocessing off-gas streams. Some of the constituents, such as NOx produced during fuel dissolution, are known to have deleterious effects on the capturemore » performance of silver-based sorbents used for iodine removal. Commercially available reduced silver mordenite (AgZ) has an iodine saturation concentration of 7.0-9.0 wt%, and its iodine sorption capacity is reduced by 20-50% as a result of NO2 aging. Silverfunctionalized silica aerogel (AgAerogel), an alternative for iodine capture, has an initial iodine saturation of 29.0 wt% and its iodine capacity is only reduced by 15% from NO2 aging. Understanding the differences in aging behavior between AgZ and AgAerogel is critical to determining the behavior of these sorbents under realistic off-gas conditions. To assist in future technical studies on this topic, samples of both AgZ and AgAerogel were aged with NO2. In the experiment, 10.2190 g of AgZ and 10.1771 g of AgAerogel were exposed to a static 0.75% NO 2/dry air blend for a period of 28 days. The samples were then removed and stored under argon until needed for future experiments.=« less

Corrective Action Investigation Plan for Corrective Action Unit 527: Horn Silver Mine, Nevada Test Site, Nevada: Revision 1 (Including Records of Technical Change No.1, 2, 3, and 4)

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

U.S. Department of Energy, National Nuclear Security Administration Nevada Operations Office

This Corrective Action Investigation Plan contains the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Operations Office's approach to collect the data necessary to evaluate corrective action alternatives appropriate for the closure of Corrective Action Unit (CAU) 527, Horn Silver Mine, Nevada Test Site, Nevada, under the Federal Facility Agreement and Consent Order. Corrective Action Unit 527 consists of one Corrective Action Site (CAS): 26-20-01, Contaminated Waste Dump No.1. The site is located in an abandoned mine site in Area 26 (which is the most arid part of the NTS) approximately 65 miles northwest of Las Vegas. Historicalmore » documents may refer to this site as CAU 168, CWD-1, the Wingfield mine (or shaft), and the Wahmonie mine (or shaft). Historical documentation indicates that between 1959 and the 1970s, nonliquid classified material and unclassified waste was placed in the Horn Silver Mine's shaft. Some of the waste is known to be radioactive. Documentation indicates that the waste is present from 150 feet to the bottom of the mine (500 ft below ground surface). This CAU is being investigated because hazardous constituents migrating from materials and/or wastes disposed of in the Horn Silver Mine may pose a threat to human health and the environment as well as to assess the potential impacts associated with any potential releases from the waste. The results of this field investigation will support a defensible evaluation of corrective action alternatives in the corrective action decision document.« less

US Army Medical Bioengineering Research and Development Laboratory Annual Progress Report for FY 82.

DTIC Science & Technology

1982-10-01

DISTRIBUTION UNLIMITED. US ARMY MEDICAL RESEARCH AND DEVELOPMENT COMMAND Fort Detrick Frederick, MD 21701 r-. , -. , 4 .. %! NOTICE Disclaimer The findings...CMPLTINGORM .REPORT 4UER 2. P3. RECIPIENT’S CATALOG NUMBER MEDDH-28 (RI) _____________ 4 . TITLE (mnd ,bu .*o) S. TYPE OF REPORT A PERIOD COVERED US Army Medical...21 Trihalomethane (THM) Degradation ......................... 23 Silver Chloride Photovoltaic Cell

The Cat, the Cradle, and the Silver Spoon: Violence in Contemporary Art and the Question of Ethics for Art Education

ERIC Educational Resources Information Center

Tavin, Kevin; Kallio-Tavin, Mira

2014-01-01

Against the backdrop of objective and subjective violence, two contemporary artworks are interpreted through theories of the Other. Zhu Yu's "Eating People" (2000) is considered through Lacanian psychoanalytic theory and, in particular, through an Ethics of the Real. Teemu Mäki's "My Way, a Work in Progress" (1995) is…

Miconia biocontrol: Where are we going and when will we get there?

Treesearch

M.T. Johnson

2010-01-01

We have made much progress in evaluating potential agents for biocontrol of miconia, and several appear likely to be suitable for future introduction to Hawaiÿi. Unfortunately, none of them is an obvious silver bullet. We face the challenge of prioritizing the existing candidates and inventing the combination of agents that will achieve our goals. Now is an opportune...

An alternate technique of care using silver fluoride followed by stannous fluoride in the management of root caries in aged care.

PubMed

Deutsch, Alan

2016-01-01

An alternate technique of care to prevent, arrest and manage root caries using aqueous silver fluoride followed by stannous fluoride (AgF+SnF2) in aged care is demonstrated by three case studies. With increasing age, the inability to maintain ones own oral care from dementia, illness or frailty and polypharmacy induced salivary gland hypofunction will result in dental caries becoming a progessively greater burden for the elderly. Future generations of elders will live longer and need to maintain many more teeth longer than earlier generations. Both silver diamine fluoride (SDF)and AgF+SnF2 arrest and prevent caries and are easy to use in residential aged care facilities. Clinical differences between SDF and AgF+SnF2 are discussed. However, in aged care, AgF+SnF2 may offer advantages over SDF. AgF+SnF2 used to arrest and prevent caries in children can be modified to provide effective but minimally invasive care for an ageing and frail population. These techniques are rapid, inexpensive and nonthreatening suited to treat frail elders, dementia patients exhibiting challenging behaviours and patients with multiple rapidly progressing decay. Silver fluoride, applied before placing glass-ionomer cement (GIC) restorations is an important adjunct to the atraumatic restorative technique and may retard caries reactivation more than GIC used alone. © 2015 Special Care Dentistry Association and Wiley Periodicals, Inc.

48 CFR 2011.104-70 - NRC Clauses.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Technical Reports, when deliverables include a technical report. (b) The contracting officer shall insert the clause at 2052.211-71 Technical Progress Report, in all solicitations and contracts except— (1...) The contracting officer shall insert the clause at 2052.211-72 Financial Status Report, in applicable...

48 CFR 2011.104-70 - NRC Clauses.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Technical Reports, when deliverables include a technical report. (b) The contracting officer shall insert the clause at 2052.211-71 Technical Progress Report, in all solicitations and contracts except— (1...) The contracting officer shall insert the clause at 2052.211-72 Financial Status Report, in applicable...

48 CFR 2011.104-70 - NRC Clauses.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Technical Reports, when deliverables include a technical report. (b) The contracting officer shall insert the clause at 2052.211-71 Technical Progress Report, in all solicitations and contracts except— (1...) The contracting officer shall insert the clause at 2052.211-72 Financial Status Report, in applicable...

48 CFR 2011.104-70 - NRC Clauses.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Technical Reports, when deliverables include a technical report. (b) The contracting officer shall insert the clause at 2052.211-71 Technical Progress Report, in all solicitations and contracts except— (1...) The contracting officer shall insert the clause at 2052.211-72 Financial Status Report, in applicable...

48 CFR 2011.104-70 - NRC Clauses.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Technical Reports, when deliverables include a technical report. (b) The contracting officer shall insert the clause at 2052.211-71 Technical Progress Report, in all solicitations and contracts except— (1...) The contracting officer shall insert the clause at 2052.211-72 Financial Status Report, in applicable...

32 CFR 203.17 - Technical assistance provider reporting requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 2 2010-07-01 2010-07-01 false Technical assistance provider reporting requirements. 203.17 Section 203.17 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY... technical assistance provider shall submit progress reports, financial status reports, materials prepared...

32 CFR 203.17 - Technical assistance provider reporting requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 32 National Defense 2 2014-07-01 2014-07-01 false Technical assistance provider reporting requirements. 203.17 Section 203.17 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY... technical assistance provider shall submit progress reports, financial status reports, materials prepared...

32 CFR 203.17 - Technical assistance provider reporting requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 32 National Defense 2 2013-07-01 2013-07-01 false Technical assistance provider reporting requirements. 203.17 Section 203.17 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY... technical assistance provider shall submit progress reports, financial status reports, materials prepared...

32 CFR 203.17 - Technical assistance provider reporting requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 32 National Defense 2 2011-07-01 2011-07-01 false Technical assistance provider reporting requirements. 203.17 Section 203.17 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY... technical assistance provider shall submit progress reports, financial status reports, materials prepared...

32 CFR 203.17 - Technical assistance provider reporting requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 32 National Defense 2 2012-07-01 2012-07-01 false Technical assistance provider reporting requirements. 203.17 Section 203.17 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY... technical assistance provider shall submit progress reports, financial status reports, materials prepared...

ISABELLE: a progress report

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

Hahn, H

This paper discusses the ISABELLE project, which has the objective of constructing a high-energy proton colliding beam facility at Brookhaven National Laboratory. The major technical features of the intersecting storage accelerators with their projected performance are described. Application of over 1000 superconducting magnets in the two rings represents the salient characteristic of the machine. The status of the entire project, the technical progress made so far, and difficulties encountered are reviewed.

Final Technical Progress Report: Development of Low-Cost Suspension Heliostat; December 7, 2011 - December 6, 2012

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

Bender, W.

2013-01-01

Final technical progress report of SunShot Incubator Solaflect Energy. The project succeeded in demonstrating that the Solaflect Suspension Heliostat design is viable for large-scale CSP installations. Canting accuracy is acceptable and is continually improving as Solaflect improves its understanding of this design. Cost reduction initiatives were successful, and there are still many opportunities for further development and further cost reduction.

Measurement of solids motion in gas-fluidized beds. Technical progress report, 1 October 1982-31 December 1982

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

Chen, M.M.; Chao, B.T.

This technical progress report covers the progress made during the fifth quarter of the project entitled Measurements of Solids Motion in Gas Fluidized Beds under Grant No. DOE-F22-81PC40804 during the period 1 October through 31 December 1982. The research concerns the measurement of solids particle velocity distribution and residence time distribution using the Computer-Aided Particle Tracking Facility (CAPTF) at the University of Illinois at Urbana-Champaign. The experimental equipment and measuring methods used to determine particle size distribution and particle motion and the results obtained are presented.

IGS 1996 Analysis Center Workshop

NASA Technical Reports Server (NTRS)

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

1996-01-01

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

The 1996 NAEP Technical Report.

ERIC Educational Resources Information Center

Allen, Nancy L.; Carlson, James E.; Zelenak, Christine A.

This report documents the design, administration, and data analysis procedure of the National Assessment of Education Progress (NAEP) for 1996. It indicates the technical decisions that were made and the rationale behind them. Detailed substantive findings are not presented in this report. These chapters provide technical information about the…

Lincoln County nuclear waste project. Quarterly progress report, October 1, 1991--December 31, 1991

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

NONE

1996-03-01

This document included the following three progress reports to the Yucca Mountain Project Office on radioactive waste storage in Lincoln County, Nevada: financial status report; federal cash transactions report; and technical progress report.

Lincoln County nuclear waste project. Quarterly progress report, January 1, 1992--March 31, 1992

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

NONE

1996-03-01

This document included the following three progress reports to the Yucca Mountain Project Office on radioactive waste storage in Lincoln County, Nevada: financial status report; federal cash transactions report; and technical progress report.

Lincoln County nuclear waste project quarterly progress report, April 1, 1992--June 30, 1992

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

NONE

1996-03-01

This document included the following three progress reports to the Yucca Mountain Project Office on radioactive waste storage in Lincoln County, Nevada: financial status report; federal cash transactions report; and technical progress report.

Index to Nuclear Safety: a technical progress review by chronology, permuted title, and author, Volume 18 (1) through Volume 22 (6)

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

Cottrell, W.B.; Passiakos, M.

This index to Nuclear Safety covers articles published in Nuclear Safety, Volume 18, Number 1 (January-February 1977) through Volume 22, Number 6 (November-December 1981). The index is divided into three section: a chronological list of articles (including abstracts), a permuted-title (KWIC) index, and an author index. Nuclear Safety, a bimonthly technical progress review prepared by the Nuclear Safety Information Center, covers all safety aspects of nuclear power reactors and associated facilities. Over 300 technical articles published in Nuclear Safety in the last 5 years are listed in this index.

Evaluation of the Flying Qualities Requirements of MIL-F-8785B (ASG) using the C-5A Airplane

DTIC Science & Technology

1975-03-20

using only the elevator control (neutralizing the aileron and rudder controls is allowed). The same tech - nique used to recover from post-stall gyrations...AD-AO11 728 EVALUATION OF THE FLYING QUALITIES REQUIREMENTS OF MIL- F-8785B (ASG) USING THE C-5A AIRPLANE Charles L. Silvers, et al Lockheed-Geor-gia...75-3 00 EVALUATION OF THE FLYING QUALITIES •- ~REQUIRIMENTS OF MIL-F-878S5 (ASO) USING THE C-SA AIRPLANE LOCKHEED-GEORGIA COMPANY TECHNICAL REPORT

Preliminary Reports, Memoranda and Technical Notes of the Materials Research Council Summer Conference, La Jolla, CA

DTIC Science & Technology

1975-07-01

1298 (1974); T. Wei, S. Etemad, A. F. Garito and A. J. Heeger, Phys. Lett. 4_5a 269 (1973). G. A. Vhomas, et. al .. Solid State Comm. 0£, 000...C. Beer, Eds. (Academic Press, New York 1975) Vol. 11 (to be published). H. Fetterman et al ., IEEE Trans. MTT-22, 1013 (1974) 8. A. H. Silver...increasing temperature over extensive ranges. Such measure- ments were reported by Johnston et al .?1 for the fast ionic conductor RbAgJ,. Thermal

77 FR 16250 - Notice of Proposed Information Collection for Public Comment; Office of Native American Programs...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-20

... Information Collection for Public Comment; Office of Native American Programs (ONAP) Training and Technical... subject proposal. The data required by Office of Native American Programs Training and Technical... progress. The data identifies needs, outputs and outcomes of the training and technical assistance. DATES...

Social inequalities in the face of scientific and technological development: an antinomy or an historic problem?

PubMed

Delgado, Guilherme Costa

2017-07-01

This paper aims to conduct a conceptual analysis of the relationship between scientific and technical progress and social equality, or the reduction of inequalities. We examine this relationship by drawing on three theoretical perspectives: 1) ethical economics, championed by classical economic thinkers and centered on utilitarian self-interest, 2) Mainstream theories of economic development espousing the endogenous link between labor productivity growth and technical progress, 3) the critique of theories of economic development that emerged in the second half of the twentieth century, including Celso Furtado's critique of the theory of underdevelopment, emphasizing the prevalence of egalitarian tendencies, and ecological economics, which suggest alternative paths to those set by "classical" theories of development. The fundamental antinomy posed by the title of this article, characterized by an intrinsic contradiction between technical progress and social equality, strictly presupposes the ethical economics perspective, dominated by the social relations that constitute the "social order".

Silver-containing foam dressings with Safetac: a review of the scientific and clinical data.

PubMed

Davies, Phil; McCarty, Sara; Hamberg, Kristina

2017-06-01

Background Topical antimicrobials, such as silver dressings, are progressively being used alongside systemic antibiotics to provide adjunctive, antimicrobial therapy to wounds that are clinically infected or at risk of infection. To help improve wound management, dressings that use Safetac soft silicone technology in combination with a silver-impregnated foam dressing material were developed by Mölnlycke Health Care (Gothenburg, Sweden). The range comprises Mepilex Ag, Mepilex Border Ag and Mepilex Transfer Ag. Aims A literature review was undertaken to identify and summarise clinical data from the entire evidence hierarchy, as well as data from in vitro tests, which support the use of silver-containing foam dressings with Safetac. Method The MEDLINE (National Library of Medicine, Bethesda, US) and EMBASE (Elsevier BV, Amsterdam, Netherlands) bibliographic databases were searched. In addition, abstract books and proceedings documents relating to national and international conferences were scanned in order to identify presentations (oral, e-poster and poster) of relevance to the review. Results In vitro test results showed that the silver-containing foam dressings with Safetac have both rapid and sustained activity against a range of wound pathogens, reducing planktonic and established biofilm cultures, and preventing biofilm formation. In numerous clinical studies, silvercontaining foam dressings with Safetac were used to manage wound bioburden effectively and resolve signs of localised infection in both acute wounds (such as surgical, traumatic and burn injuries) and chronic wounds (such as leg ulcers, pressure ulcers (PUs), diabetic foot ulcers (DFUs), and cancerous wounds). Studies reported that silver-containing foam dressings with Safetac are easy to use, provide an optimal environment for wound healing, and are associated with atraumatic and virtually painfree removal. As well as being clinically effective, they are reported to be cost-effective when used on wounds that require topical antimicrobial therapy. Conclusion The findings of both scientific and clinical studies clearly indicate that clinical, patient-related and economic benefits are associated with the use of Mepilex Ag, Mepilex Border Ag and Mepilex Transfer Ag with Safetac in the treatment of wounds where antimicrobial activity is needed to help manage bioburden.

Comparative evaluation of antimicrobials for textile applications.

PubMed

Windler, Lena; Height, Murray; Nowack, Bernd

2013-03-01

Many antimicrobial technologies are available for textiles. They may be used in many different textile applications to prevent the growth of microorganisms. Due to the biological activity of the antimicrobial compounds, the assessment of the safety of these substances is an ongoing subject of research and regulatory scrutiny. This review aims to give an overview on the main compounds used today for antimicrobial textile functionalization. Based on an evaluation of scientific publications, market data as well as regulatory documents, the potential effects of antimicrobials on the environment and on human health were considered and also life cycle perspectives were taken into account. The characteristics of each compound were summarized according to technical, environmental and human health criteria. Triclosan, silane quaternary ammonium compounds, zinc pyrithione and silver-based compounds are the main antimicrobials used in textiles. The synthetic organic compounds dominate the antimicrobials market on a weight basis. On the technical side the application rates of the antimicrobials used to functionalize a textile product are an important parameter with treatments requiring lower dosage rates offering clear benefits in terms of less active substance required to achieve the functionality. The durability of the antimicrobial treatment has a strong influence on the potential for release and subsequent environmental effects. In terms of environmental criteria, all compounds were rated similarly in effective removal in wastewater treatment processes. The extent of published information about environmental behavior for each compound varies, limiting the possibility for an in-depth comparison of all textile-relevant parameters across the antimicrobials. Nevertheless the comparative evaluation showed that each antimicrobial technology has specific risks and benefits that should be taken into account in evaluating the suitability of different antimicrobial products. The results also indicated that nanoscale silver and silver salts that achieve functionality with very low application rates offer clear potential benefits for textile use. The regular care of textiles consumes lots of resources (e.g. water, energy, chemicals) and antimicrobial treatments can play a role in reducing the frequency and/or intensity of laundering which can give potential for significant resource savings and associated impact on the environment. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of fluid flux on the width of contact metamorphic aureoles: evidence from Silver Star, Montana

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

Foote, M.V.; Frost, B.R.; Angevine, C.L.

1985-01-01

Contact metamorphism of Paleozoic carbonate-rich sediments by the Boulder Batholith near Silver Star, Montana has resulted in the formation of the following six metamorphic zones: (1) calcite (cc) - dolomite (dol) - quartz (q) - phlogopite (phl) +/- kspar (ksp); (b) cc - dol - tremolite (tr) - q - ksp; (c) cc - dol - tr - diopside (di) - phl; (d) cc - dol - di - forsterite (fo) - phl; (e) cc - dol - fo, and cc - di - fo; and (f) cc - fo - periclase +/- dol. The presence of periclase in themore » highest zone indicates that these rocks crystallized in the presence of a water-rich fluid. Calculations of reaction progress indicate that between zone e and zone f, 4.5 rock-volumes of water had to be introduced. Comparison of the aureole at Silver Star with other contact aureoles studied around the Boulder Batholith shows a distinct correlation between the width of the aureole and the inferred fluid flux. The Boulder and Marysville aureoles are internally buffered throughout and have a width (measured to the tremolite-in isograd) of up to 1.5 km, while the Black Butte aureole, which has largely external control of the fluid, has a width of approximately 80 meters. Silver Star, which is intermediate in behavior, has an aureole width of approximately 250 meters. The indicates that in environments of low fluid flux heat is transported largely by conduction, while in environments of low fluid flux most of the heat is transported upward by convective flow, resulting in correspondingly narrower aureoles.« less

Developments in Technical Education in the British Caribbean, 1940-60.

ERIC Educational Resources Information Center

Pemberton, S. Macpherson

The paper discusses developments in technical education in the British West Indies from 1940-1960 emphasizing the relation between education and economic development. The objective is to analyze the economic basis of progress in technical education. The document is presented in four chapters. Chapter I summarizes historical background prior to…

Programs of Study: Year 2 Joint Technical Report. Research Snapshot

ERIC Educational Resources Information Center

National Research Center for Career and Technical Education, 2010

2010-01-01

In January 2010, the National Research Center for Career and Technical Education (NRCCTE) issued a progress report on three studies being conducted by the Center that examine the implementation and outcomes of Programs of Study (POS), which were required in the 2006 reauthorization of the federal legislation for career and technical education…

Zinc Pyrithione Improves the Antibacterial Activity of Silver Sulfadiazine Ointment

PubMed Central

Blanchard, Catlyn; Brooks, Lauren; Ebsworth-Mojica, Katherine; Didione, Louis; Wucher, Benjamin; Dewhurst, Stephen; Krysan, Damian

2016-01-01

ABSTRACT Pseudomonas aeruginosa, Acinetobacter baumannii, and Staphylococcus aureus are commonly associated with biofilm-associated wound infections that are recalcitrant to conventional antibiotics. As an initial means to identify agents that may have a greater propensity to improve clearance of wound-associated bacterial pathogens, we screened a Food and Drug Administration-approved drug library for members that display bactericidal activity toward 72-h-established P. aeruginosa biofilms using an adenylate kinase reporter assay for bacterial cell death. A total of 34 compounds displayed antibiofilm activity. Among these, zinc pyrithione was also shown to reduce levels of A. baumannii and S. aureus biofilm-associated bacteria and exhibited an additive effect in combination with silver sulfadiazine, a leading topical therapeutic for wound site infections. The improved antimicrobial activity of zinc pyrithione and silver sulfadiazine was maintained in an ointment formulation and led to improved clearance of P. aeruginosa, A. baumannii, and S. aureus in a murine model of wound infection. Taken together, these results suggest that topical zinc pyrithione and silver sulfadiazine combination formulations may mitigate wound-associated bacterial infections and disease progression. IMPORTANCE Topical antimicrobial ointments ostensibly mitigate bacterial wound disease and reliance on systemic antibiotics. Yet studies have called into question the therapeutic benefits of several traditional topical antibacterials, accentuating the need for improved next-generation antimicrobial ointments. Yet the development of such agents consisting of a new chemical entity is a time-consuming and expensive proposition. Considering that drug combinations are a mainstay therapeutic strategy for the treatment of other therapeutic indications, one alternative approach is to improve the performance of conventional antimicrobial ointments by the addition of a well-characterized and FDA-approved agent. Here we report data that indicate that the antimicrobial properties of silver sulfadiazine ointments can be significantly improved by the addition of the antifungal zinc pyrithione, suggesting that such combinations may provide an improved therapeutic option for the topical treatment of wound infections. PMID:27642637

Qualification process of CR system and quantification of digital image quality

NASA Astrophysics Data System (ADS)

Garnier, P.; Hun, L.; Klein, J.; Lemerle, C.

2013-01-01

CEA Valduc uses several X-Ray generators to carry out many inspections: void search, welding expertise, gap measurements, etc. Most of these inspections are carried out on silver based plates. For several years, the CEA/Valduc has decided to qualify new devices such as digital plates or CCD/flat panel plates. On one hand, the choice of this technological orientation is to forecast the assumed and eventual disappearance of silver based plates; on the other hand, it is also to keep our skills mastering up-to-date. The main improvement brought by numerical plates is the continuous progress of the measurement accuracy, especially with image data processing. It is now common to measure defects thickness or depth position within a part. In such applications, data image processing is used to obtain complementary information compared to scanned silver based plates. This scanning procedure is harmful for measurements which imply a data corruption of the resolution, the adding of numerical noise and is time expensive. Digital plates enable to suppress the scanning procedure and to increase resolution. It is nonetheless difficult to define, for digital images, single criteria for the image quality. A procedure has to be defined in order to estimate quality of the digital data itself; the impact of the scanning device and the configuration parameters are also to be taken into account. This presentation deals with the qualification process developed by CEA/Valduc for digital plates (DUR-NDT) based on the study of quantitative criteria chosen to define a direct numerical image quality that could be compared with scanned silver based pictures and the classical optical density. The versatility of the X-Ray parameters is also discussed (X-ray tension, intensity, time exposure). The aim is to be able to transfer the year long experience of CEA/Valduc with silver-based plates inspection to these new digital plates supports. This is an industrial stake.

Necrotizing fasciitis secondary to enterocutaneous fistula: three case reports.

PubMed

Gu, Guo-Li; Wang, Lin; Wei, Xue-Ming; Li, Ming; Zhang, Jie

2014-06-28

Necrotizing fasciitis (NF) is an uncommon, rapidly progressive, and potentially fatal infection of the superficial fascia and subcutaneous tissue. NF caused by an enterocutaneous fistula has special clinical characters compared with other types of NF. NF caused by enterocutaneous fistula may have more rapid progress and more severe consequences because of multiple germs infection and corrosion by digestive juices. We treated three cases of NF caused by postoperative enterocutaneous fistula since Jan 2007. We followed empirically the principle of eliminating anaerobic conditions of infection, bypassing or draining digestive juice from the fistula and changing dressings with moist exposed burn therapy impregnated with zinc/silver acetate. These three cases were eventually cured by debridement, antibiotics and wound management.

Proceedings: Computer Science and Data Systems Technical Symposium, volume 1

NASA Technical Reports Server (NTRS)

Larsen, Ronald L.; Wallgren, Kenneth

1985-01-01

Progress reports and technical updates of programs being performed by NASA centers are covered. Presentations in viewgraph form are included for topics in three categories: computer science, data systems and space station applications.

Optical Materials with a Genome: Nanophotonics with DNA-Stabilized Silver Clusters

NASA Astrophysics Data System (ADS)

Copp, Stacy M.

Fluorescent silver clusters with unique rod-like geometries are stabilized by DNA. The sizes and colors of these clusters, or AgN-DNA, are selected by DNA base sequence, which can tune peak emission from blue-green into the near-infrared. Combined with DNA nanostructures, AgN-DNA promise exciting applications in nanophotonics and sensing. Until recently, however, a lack of understanding of the mechanisms controlling AgN-DNA fluorescence has challenged such applications. This dissertation discusses progress toward understanding the role of DNA as a "genome" for silver clusters and toward using DNA to achieve atomic-scale precision of silver cluster size and nanometer-scale precision of silver cluster position on a DNA breadboard. We also investigate sensitivity of AgN-DNA to local solvent environment, with an eye toward applications in chemical and biochemical sensing. Using robotic techniques to generate large data sets, we show that fluorescent silver clusters are templated by certain DNA base motifs that select "magic-sized" cluster cores of enhanced stabilities. The linear arrangement of bases on the phosphate backbone imposes a unique rod-like geometry on the clusters. Harnessing machine learning and bioinformatics techniques, we also demonstrate that sequences of DNA templates can be selected to stabilize silver clusters with desired optical properties, including high fluorescence intensity and specific fluorescence wavelengths, with much higher rates of success as compared to current strategies. The discovered base motifs can be also used to design modular DNA host strands that enable individual silver clusters with atomically precise sizes to bind at specific programmed locations on a DNA nanostructure. We show that DNA-mediated nanoscale arrangement enables near-field coupling of distinct clusters, demonstrated by dual-color cluster assemblies exhibiting resonant energy transfer. These results demonstrate a new degree of control over the optical properties and relative positions of nanoparticles, selected almost solely by the sequence of DNA. AgN-DNA are promising chemical and biochemical sensors due to the sensitivity of their fluorescence to local environment. However, the mechanisms behind many sensing schemes are not understood, and the nature of the excited state of the silver cluster itself remains unknown. To probe the fluorescence mechanisms of AgN-DNA, we investigate the behavior of purified solutions of these clusters in various solvents. We find that standard models for fluorophore solvatochromism, including the Lippert-Mataga model, do not describe AgN-DNA fluorescence because such models neglect specific interactions between the cluster and surrounding solvent molecules. Fluorescence colors are well-modeled by Mie-Gans theory, suggesting that the local dielectric environment of the cluster does play a role in fluorescence, although additional specific solvent interactions and cluster shape changes may also determine fluorescence color and intensity. These results suggest that AgN-DNA may be sensitive to changes in local dielectric environment on nanometer length scales and may also act as sensors for small molecules with affinity for DNA.

Technical progress in silicon sheet growth under DOE/JPL FSA program, 1975-1986

NASA Technical Reports Server (NTRS)

Kalejs, J. P.

1986-01-01

The technical progress made in the Silicon Sheet Growth Program during its 11 years was reviewed. At present, in 1986, only two of the original 9 techniques have survived to the start-up, pilot-plant stage in industry. These two techniques are the edge-defined, film-fed growth (EFG) technique that produces closed shape polygons, and the WEB dendritic technique that produces single ribbons. Both the status and future concerns of the EFG and WEB techniques were discussed.

Annual Progress Report (17th) and 1992-97 Renewal Proposal Interactive Graphics for Molecular Studies

DTIC Science & Technology

1991-01-24

Molecular Graphics, vol. 6, No. 4 (Dec. 1988), p. 223. Turk, Greg, "Interactive Collision Detection for Molecular Graphics," M.S. thesis , UNC-Chapel Hill...Problem," Master’s thesis , UNC Department of Computer Science Technical Report #TR87-013, May 1987. Pique, ME., "Technical Trends in Molecular Graphics...AD-A236 598 Seventeenth Annual Progress Report and 1992-97 Renewal Proposal Interactive Graphics for Molecular Studies TR91-020 January 24, 1991 red

Enhanced oil recovery utilizing high-angle wells in the Frontier Formation, Badger Basin Field, Park County, Wyoming. Quarterly technical progress report, 1 March 1993--30 June 1993

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

Fortmann, R.G.; Walker, J.P.

1993-07-10

Sierra Energy Company`s targeted goals during the third quarter of this Cooperative Agreement included the following objectives from the Statement of Work: in Phase 2A, completion of subtask 2.1.2--acquire best possible field data in the 3-D seismic program; and initiation of Subtask 2.1.3--process acquired 3-D seismic data. Technical progress is described for these tasks.

10 CFR 603.1100 - Contracting officer's post-award responsibilities.

Code of Federal Regulations, 2011 CFR

2011-01-01

... technical progress, financial status, and future program plans. (b) Tracking and processing of reports... progress reports, and patent reports. (c) Handling payment requests and related matters. For a TIA using advance payments, that includes reviews of progress to verify that there is continued justification for...

7 CFR 3402.23 - Documentation of progress on funded projects.

Code of Federal Regulations, 2011 CFR

2011-01-01

... the academic program due to unsatisfactory academic progress; or voluntarily withdraws from the Fellowship or the academic program. If a Fellow has not completed all degree requirements at the end of the... database contains narrative project information, progress/impact statements, and final technical reports...

7 CFR 3402.23 - Documentation of progress on funded projects.

Code of Federal Regulations, 2014 CFR

2014-01-01

... the academic program due to unsatisfactory academic progress; or voluntarily withdraws from the Fellowship or the academic program. If a Fellow has not completed all degree requirements at the end of the... database contains narrative project information, progress/impact statements, and final technical reports...

7 CFR 3402.23 - Documentation of progress on funded projects.

Code of Federal Regulations, 2012 CFR

2012-01-01

... the academic program due to unsatisfactory academic progress; or voluntarily withdraws from the Fellowship or the academic program. If a Fellow has not completed all degree requirements at the end of the... database contains narrative project information, progress/impact statements, and final technical reports...

7 CFR 3402.23 - Documentation of progress on funded projects.

Code of Federal Regulations, 2013 CFR

2013-01-01

... the academic program due to unsatisfactory academic progress; or voluntarily withdraws from the Fellowship or the academic program. If a Fellow has not completed all degree requirements at the end of the... database contains narrative project information, progress/impact statements, and final technical reports...

NAEP 1999 Long-Term Trend Technical Analysis Report: Three Decades of Student Performance. NCES 2005-484

ERIC Educational Resources Information Center

Allen, Nancy L.; McClellan, Catherine A.; Stoeckel, Joan J.

2005-01-01

This report provides an update to the technical analysis procedures documenting the 1996 National Assessment of Educational Progress (NAEP) as presented in "The NAEP 1996 Technical Report" (Allen, Carlson, and Zelenak, 1999). It describes how the 1999 long-term trend data were incorporated into the trend analyses. Since no national main…

Technologies for diagnosis and treatment of acute stroke

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

Fitch, J.P.

1998-02-09

From October 1994 to June 1997, a multidisciplinary team of scientists and engineers at Lawrence Livermore National Laboratory were funded through LDRD to develop and integrate technologies for diagnosis and treatment of acute stroke. The project was summarized in a Science and Technology Review article `Brain Attack` that appeared in June 1997 and again in the Center for Healthcare Technologies Report (UCRL-LR-124761). This article is the best overview of the project, epidemiology of stroke and technical progress. Most of the technical progress has been documented in conference papers and presentations and refereed journal articles. Additional technical publication can be expectedmore » as our remaining patent applications progress through the US Patent and Trademark Office. The purpose of this report is to provide an appropriate introduction and organization to the numerous publications so that interested readers can quickly find information. Because there is no documentation for the history of this project, this report provides a summary. It also provides the final status report for the LDRD funding.« less

Proceedings: Computer Science and Data Systems Technical Symposium, volume 2

NASA Technical Reports Server (NTRS)

Larsen, Ronald L.; Wallgren, Kenneth

1985-01-01

Progress reports and technical updates of programs being performed by NASA centers are covered. Presentations in viewgraph form, along with abstracts, are included for topics in three catagories: computer science, data systems, and space station applications.

A study on operation efficiency evaluation based on firm's financial index and benchmark selection: take China Unicom as an example

NASA Astrophysics Data System (ADS)

Wu, Zu-guang; Tian, Zhan-jun; Liu, Hui; Huang, Rui; Zhu, Guo-hua

2009-07-01

Being the only listed telecom operators of A share market, China Unicom has always been attracted many institutional investors under the concept of 3G recent years,which itself is a great technical progress expectation.Do the institutional investors or the concept of technical progress have signficant effect on the improving of firm's operating efficiency?Though reviewing the documentary about operating efficiency we find that schoolars study this problem useing the regress analyzing based on traditional production function and data envelopment analysis(DEA) and financial index anayzing and marginal function and capital labor ratio coefficient etc. All the methods mainly based on macrodata. This paper we use the micro-data of company to evaluate the operating efficiency.Using factor analyzing based on financial index and comparing the factor score of three years from 2005 to 2007, we find that China Unicom's operating efficiency is under the averge level of benchmark corporates and has't improved under the concept of 3G from 2005 to 2007.In other words,institutional investor or the conception of technical progress expectation have faint effect on the changes of China Unicom's operating efficiency. Selecting benchmark corporates as post to evaluate the operating efficiency is a characteristic of this method ,which is basicallly sipmly and direct.This method is suit for the operation efficiency evaluation of agriculture listed companies because agriculture listed also face technical progress and marketing concept such as tax-free etc.

Decontamination Systems Information and Research Program. Quarterly technical progress report, January 1--March 31, 1994

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

Not Available

1994-05-01

West Virginia University (WVU) and the US DOE Morgantown Energy Technology Center (METC) entered into a Cooperative Agreement on August 29, 1992 entitled ``Decontamination Systems Information and Research Programs.`` Stipulated within the Agreement is the requirement that WVU submit to METC a series of Technical Progress Reports on a quarterly basis. This report comprises the first Quarterly Technical Progress Report for Year 2 of the Agreement. This report reflects the progress and/or efforts performed on the sixteen (16) technical projects encompassed by the Year 2 Agreement for the period of January 1 through March 31, 1994. In situ bioremediation ofmore » chlorinated organic solvents; Microbial enrichment for enhancing in-situ biodegradation of hazardous organic wastes; Treatment of volatile organic compounds (VOCs) using biofilters; Drain-enhanced soil flushing (DESF) for organic contaminants removal; Chemical destruction of chlorinated organic compounds; Remediation of hazardous sites with steam reforming; Soil decontamination with a packed flotation column; Use of granular activated carbon columns for the simultaneous removal of organics, heavy metals, and radionuclides; Monolayer and multilayer self-assembled polyion films for gas-phase chemical sensors; Compact mercuric iodide detector technology development; Evaluation of IR and mass spectrometric techniques for on-site monitoring of volatile organic compounds; A systematic database of the state of hazardous waste clean-up technologies; Dust control methods for insitu nuclear and hazardous waste handling; Winfield Lock and Dam remediation; and Socio-economic assessment of alternative environmental restoration technologies.« less

Nucleosynthesis in the early Galaxy: Progress and challenges.

NASA Astrophysics Data System (ADS)

Montes, Fernando

2015-10-01

Chemical imprints left by the first stars in the oldest stars of the Milky Way gives clues of the stellar nucleosynthesis responsible for the creation of elements heavier than iron. Recent progress in astronomical observations and in the modeling of the chemical evolution of the Galaxy have shown that multiple nucleosynthesis processes may operate at those early times. In this talk I will review some of that evidence along with the important role that nuclear reactions play in those processes. I will focus in progress in our understanding of the rapid neutron capture process (r-process) and in new results on nucleosynthesis in core-collapse supernovae and neutrino-driven winds that produce elements up to silver. I will show some examples of recent nuclear physics measurements addressing the need for better nuclear data and give an outlook of the remaining challenges and future plans to continue those measurements.

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

Seizing the Future: How Ohio's Career-Technical Education Programs Fuse Academic Rigor and Real-World Experiences to Prepare Students for College and Careers

ERIC Educational Resources Information Center

Guarino, Heidi; Yoder, Shaun

2015-01-01

"Seizing the Future: How Ohio's Career and Technical Education Programs Fuse Academic Rigor and Real-World Experiences to Prepare Students for College and Work," demonstrates Ohio's progress in developing strong policies for career and technical education (CTE) programs to promote rigor, including college- and career-ready graduation…

Case Study on Technical and Vocational Education in Japan. Case Studies on Technical and Vocational Education in Asia and the Pacific.

ERIC Educational Resources Information Center

Iwamoto, Muneharu

In the course of Japan's economic progress, remarkable changes have occurred in the structure of industry and employment. Workers are in extremely short supply in such occupations as mining, manufacturing and construction, services, transportation and communication, sales, and professional and technical. On the basis of recommendations of the…

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

USGS Publications Warehouse

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

2012-01-01

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

25 CFR 30.104 - What is the Secretary's definition of AYP?

Code of Federal Regulations, 2011 CFR

2011-04-01

... PROGRESS Defining Adequate Yearly Progress § 30.104 What is the Secretary's definition of AYP? The... accepted by the Department of Education. The Secretary is committed to providing technical assistance to a...

25 CFR 30.104 - What is the Secretary's definition of AYP?

Code of Federal Regulations, 2010 CFR

2010-04-01

... PROGRESS Defining Adequate Yearly Progress § 30.104 What is the Secretary's definition of AYP? The... accepted by the Department of Education. The Secretary is committed to providing technical assistance to a...

Genetic environment of germanium-bearing gold-silver vein ores from the Wolyu mine, Republic of Korea

NASA Astrophysics Data System (ADS)

Yun, Seong-Taek; So, Chil-Sup; Choi, Sang-Hoon; Shelton, Kevin L.; Koo, Ja-Hak

1993-04-01

The Wolyu mine is one of the largest vein-type gold-silver-bearing epithermal systems in the Youngdong district and is the first gold-silver deposit in Korea found to contain significant germanium, in the form of argyrodite (Ag8GeS6). Mineralized veins (78.9 ± 1.2 Ma) crosscutting Late Cretaceous hostrock tuff and quartz porphyry (81.5 ± 1.8 Ma) consist of three stages of quartz and carbonates, the first of which contains pyrite, basemetal sulfides and Au-Ag-minerals. Stage I Au-Ag-Ge-mineralized veins show a systematic variation of mineral assemblage with time: (1) quartz + pyrite; (2) quartz + pyrite + sphalerite + electrum + argentite; (3) carbonate + quartz + sphalerite + electrum + argentite; (4) carbonate + native silver + argentite + Ag-sulfosalts + argyrodite + sphalerite. Calculated values of temperature and sulfur activity are: assemblage (1), 360-280°C and 10-7-10-10; (2), 280-210°C and 10-10-10-14; (3), 210-180°C and 10-14-10-16; (4), 180-155°C and 10-17-10-18. These data, the frequent association of gold with sulfides, and the abundance of pyrite in alteration zones indicate that decreasing sulfur activity and cooling were important in triggering gold deposition. Hydrogen and oxygen isotope compositions of ore fluids display a systematic variation with increasing time. Within the main Ag-Au-Ge mineralization, δD and δ 18O values decrease with the transition from quartz to carbonate deposition (from -78 and -2.8% to -90 and -8.7%., respectively), indicating increasing involvement (mixing) of less evolved meteoric water which resulted in progressive cooling and dilution of ore fluids in the shallow (≈ 370 600 m) Wolyu epithermal system.

HRTEM/AEM and SEM study of fluid-rock interactions: Interaction of copper, silver, selenium, chromium, and cadmium-bearing solutions with geological materials at near surface conditions, with an emphasis on phyllosilicates. Progress report, September 1, 1992--September 1, 1993

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

Veblen, D.R.; Ilton, E.S.

1993-05-01

TEM of naturally occurring Cu-rich biotites and feldspars from weathered portions of porphyry copper deposits has shown that copper is not in the structure of these minerals, is present in their weathering products such as copper-rich vermiculite layers, submicroscopic iron oxyhydroxides and native copper inclusions, and chrysocoua. Reaction of acidic solutions bearing-Cu{sup 2+}, Ag{sup +}, Cr{sup 6+}, and Se{sup 4+}, at 25C, with biotite indicates that ferrous iron in biotite can reduce Cu{sup 2+}, Ag+, and Cr{sup 6+} to Cu{degrees}, Ag{degrees}, and Cr(III), respectively. However, Se{sup 4+} does not appear to be reduced. Copper is reduced in the interlayer region,more » silver is reduced in the interlayer and on the biotite surfaces, and chromium is reduced at the biotite surface. TEM shows that the reduction of copper and silver by biotite can produce native metal inclusions, whereas reduction of Cr(VI) to CR(III) did not produce any Cr-bearing precipitates. The copper and silver experiments show that iron in biotite can be a much stronger reducing agent than iron in solution. TEM and XPS of biotites reacted with CR(VI) clearly show that edges or (hkO) faces are much more reactive than the basal planes, where the edges are strongly enriched in CR(III) relative to the basal planes. In contrast, biotites reacted with Cr(IH)-bearing solutions show little fractionation between the edges and basal planes. Another important result of our XPS studies is that we demonstrated that the oxidation state of near surface iron in biotite can be quantified.« less

Necrotizing fasciitis secondary to enterocutaneous fistula: Three case reports

PubMed Central

Gu, Guo-Li; Wang, Lin; Wei, Xue-Ming; Li, Ming; Zhang, Jie

2014-01-01

Necrotizing fasciitis (NF) is an uncommon, rapidly progressive, and potentially fatal infection of the superficial fascia and subcutaneous tissue. NF caused by an enterocutaneous fistula has special clinical characters compared with other types of NF. NF caused by enterocutaneous fistula may have more rapid progress and more severe consequences because of multiple germs infection and corrosion by digestive juices. We treated three cases of NF caused by postoperative enterocutaneous fistula since Jan 2007. We followed empirically the principle of eliminating anaerobic conditions of infection, bypassing or draining digestive juice from the fistula and changing dressings with moist exposed burn therapy impregnated with zinc/silver acetate. These three cases were eventually cured by debridement, antibiotics and wound management. PMID:24976737

ANNUAL REPORT, JULY 1, 1958

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

None

1959-02-01

This annual report of Brookhaven National Laboratory describes its program and activities for the fiscal year 1958. The progress and trends of the research program are presented along with a description of the operational, service, and administrative activities of the Laboratory. The scientific and technical details of the many research and development activities are covered more fully in scientific and technical periodicals and in the quarterly scientific progress reports and other scientiflc reports of the Laboratory. A list of all publications for July 1, 1957 to June 30, 1958, is given. Status and progress are given in fields of physics,more » accelerator development, instrumentation, applied mathematics, chemistry, nuclear engineering, biology, and medical research. (For preceding period see BNL-462.) (W.D.M.)« less

Towards a space-borne quantum gravity gradiometer: progress in laboratory demonstration

NASA Technical Reports Server (NTRS)

Yu, Nan; Kohel, James M.; Kellogg, James R.; Maleki, Lute

2005-01-01

This paper describes the working principles and technical benefits of atom-wave interferometer-based inertial sensors, and gives a progress report on the development of a quantum gravity gradiometer for space applications at JPL.

Technical Progress of the New Worlds Observer Mission

NASA Astrophysics Data System (ADS)

Lo, Amy; Noecker, C.; Cash, W.; NWO Study Team

2009-01-01

We report on the technical progress of the New Worlds Observer (NWO) mission concept. NWO is a two spacecraft mission that is capable of detecting and characterizing extra-solar, terrestrial planets and planetary systems. NWO consists of an external starshade and an UV-optical space telescope, flying in tandem. The starshade is a petal-shaped, opaque screen that creates an extremely dark shadow large enough to shade the telescope aperture from the target star. The NWO team has been addressing the top technology challenges of the concept, and report here our progress. We will present the current mission configuration best suited to address Terrestrial Planet Finding requirements, and highlight the technological breakthroughs that we have achieved this year. In particular, we will report on progress made in precision deployables for the large starshade, and the trajectory & alignment control system for NWO. We will also briefly highlight advances in understanding the starshade optical performance.

Maximizing the Utility of the Serum Repository With Current Technologies and Recommendations to Meet Future Needs: Report of the Technical Panel.

PubMed

Baird, Coleen P

2015-10-01

The Department of Defense Serum Repository (DoDSR) of the Armed Forces Health Surveillance Center (AFHSC), Silver Spring, Maryland, has over 55 million specimens. Over 80% of these specimens are linked to individual health data. In response to Congressional and Department of Defense (DoD) concern about toxic exposures of deployed Service members and rapidly developing laboratory capabilities that may identify those exposed, the AFHSC hosted two panels in 2013. The first, the Needs Panel, focused on assessing the needs of the DoD that may be met using the current DoDSR and an enhanced repository. The second panel, the Technical Panel, focused on identifying the emerging laboratory technologies that are or will be available to DoD public health workers and researchers. This report summarizes the recommendations of the Technical Panel, to include identified gaps in the ability of the current DoDSR to address questions of interest to the DoD, the availability of laboratory technology to address these needs, and the types and quality of specimens required from Service members possibly exposed. Reprint & Copyright © 2015 Association of Military Surgeons of the U.S.

Role of catalytic protein and stabilising agents in the transformation of Ag ions to nanoparticles by Pseudomonas aeruginosa.

PubMed

Ali, Jafar; Hameed, Abdul; Ahmed, Safia; Ali, Muhammad Ishtiaq; Zainab, Shama; Ali, Naeem

2016-10-01

Biological routes of synthesising metal nanoparticles (NPs) using microbes have been gaining much attention due to their low toxicity and eco-friendly nature. Pseudomonas aeruginosa JP2 isolated from metal contaminated soil was evaluated towards extracellular synthesis of silver NPs (AgNPs). Cell-free extract (24 h) of the bacterial isolate was reacted with AgNO 3 for 24 h in order to fabricate AgNPs. Preliminary observations were recorded in terms of colour change of the reaction mixture from yellow to greyish black. UV-visible spectroscopy of the reaction mixture has shown a progressive increase in optical densities that correspond to peaks near 430 nm, depicting reduction of ionic silver (Ag + ) to atomic silver (Ag 0 ) thereby synthesising NPs. X-ray diffraction spectra exhibited the 2θ values to be 38.4577° confirming the crystalline and spherical nature of NPs [9.6 - 26.7 (Ave. = 17.2 nm)]. Transmission electron microscopy finally confirmed the size of the particles varying from 5 to 60 nm. Moreover, rhamnolipids and proteins were identified as stabilising molecules for the AgNPs through Fourier transform-infrared spectroscopy. Characterisation of bacterial crude and purified protein fractions confirmed the involvement of nitrate reductase (molecular weight 66 kDa and specific activity = 3.8 U/mg) in the Synthesis of AgNPs.

Progress in UCO's search for silver-based telescope mirror coatings

NASA Astrophysics Data System (ADS)

Phillips, Andrew C.; Miller, Joseph S.; Bolte, Michael; DuPraw, Brian; Radovan, Matthew; Cowley, David

2012-09-01

We report on the on-going effort at University of California Observatories Astronomical Coatings Lab to develop robust protected-silver coatings suitable for telescope mirrors. We have identified a very promising recipe based on YF3 that produces excellent reflectivity at wavelengths of 340 nm and greater, has ~1.5% emissivity in the thermal IR, and does not contain problematic materials for the Mid-IR, such as SiO2 and Al2O3. The recipe holds up extremely well to aggressive environmental testing (80C and 80% RH; high-H2S atmosphere), and currently is being evaluated under real observatory conditions. This coating may satisfy the need for telescope mirror coatings that are long-lasting (~5 years or more) and have good reflectivity into the UV. We also evaluate and compare some other silver-based coatings developed elsewhere that should be useful in the same role. In addition, we describe recent upgrades to our coating facilities allowing us to deposit ion-assisted e-beam coatings on optics up to ~1m. This novel arrangement places the e-gun and ion source on a pivoting "swing-arm", allowing the position to move radially without changing the e-gun/ion source/ substrate geometry. Large substrates can be coated with good uniformity using single-axis rotation only. This technique is scalable to arbitrarily large substrate sizes.

Isolation of a pigment-producing strain of Aeromonas liquefaciens from silver salmon (Oncorhynchus kisutch)

USGS Publications Warehouse

Ross, A.J.

1962-01-01

Aeromonas salmonicida, the etiological agent of furunculosis in fish, is distinctive in the field of fish diseases in that it may readily be recognized by the water-soluble reddish-brown pigment formed on culture media containing tyrosine. Additional tests for the identification of this organism include blackening of the colonial growth when flooded with an aqueous solution of p-phenylenediamine and a lack of motility (Griffin, Progressive Fish Culturist 14:74, 1952).

Investigation of proposed process sequence for the array automated assembly task, phases 1 and 2

NASA Technical Reports Server (NTRS)

Mardesich, N.; Garcia, A.; Eskenas, K.

1980-01-01

Progress was made on the process sequence for module fabrication. A shift from bonding with a conformal coating to laminating with ethylene vinyl acetate and a glass superstrate is recommended for further module fabrication. The processes that were retained for the selected process sequence, spin-on diffusion, print and fire aluminum p+ back, clean, print and fire silver front contact and apply tin pad to aluminum back, were evaluated for their cost contribution.

Amarillo National Resource Center for Plutonium. Quarterly technical progress report, May 1, 1997--July 31, 1997

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

NONE

Progress summaries are provided from the Amarillo National Center for Plutonium. Programs include the plutonium information resource center, environment, public health, and safety, education and training, nuclear and other material studies.

Urology technical and non-technical skills development: the emerging role of simulation.

PubMed

Rashid, Prem; Gianduzzo, Troy R J

2016-04-01

To review the emerging role of technical and non-technical simulation in urological education and training. A review was conducted to examine the current role of simulation in urology training. A PUBMED search of the terms 'urology training', 'urology simulation' and 'urology education' revealed 11,504 titles. Three hundred and fifty-seven abstracts were identified as English language, peer reviewed papers pertaining to the role of simulation in urology and related topics. Key papers were used to explore themes. Some cross-referenced papers were also included. There is an ongoing need to ensure that training time is efficiently utilised while ensuring that optimal technical and non-technical skills are achieved. Changing working conditions and the need to minimise patient harm by inadvertent errors must be taken into account. Simulation models for specific technical aspects have been the mainstay of graduated step-wise low and high fidelity training. Whole scenario environments as well as non-technical aspects can be slowly incorporated into the curriculum. Doing so should also help define what have been challenging competencies to teach and evaluate. Dedicated time, resources and trainer up-skilling are important. Concurrent studies are needed to help evaluate the effectiveness of introducing step-wise simulation for technical and non-technical competencies. Simulation based learning remains the best avenue of progressing surgical education. Technical and non-technical simulation could be used in the selection process. There are good economic, logistic and safety reasons to pursue the process of ongoing development of simulation co-curricula. While the role of simulation is assured, its progress will depend on a structured program that takes advantage of what can be delivered via this medium. Overall, simulation can be developed further for urological training programs to encompass technical and non-technical skill development at all stages, including recertification. © 2015 The Authors BJU International © 2015 BJU International Published by John Wiley & Sons Ltd.

A Portfolio Analysis Tool for Measuring NASAs Aeronautics Research Progress toward Planned Strategic Outcomes

NASA Technical Reports Server (NTRS)

Tahmasebi, Farhad; Pearce, Robert

2016-01-01

Description of a tool for portfolio analysis of NASA's Aeronautics research progress toward planned community strategic Outcomes is presented. The strategic planning process for determining the community Outcomes is also briefly described. Stakeholder buy-in, partnership performance, progress of supporting Technical Challenges, and enablement forecast are used as the criteria for evaluating progress toward Outcomes. A few illustrative examples are also presented.

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.

Manufacturing and testing of wavefront filters for DARWIN

NASA Astrophysics Data System (ADS)

Flatscher, R.; Artjushenko, V.; Sakharova, T.; Pereira do Carmo, Joao

2017-11-01

Wavefront filtering is mandatory in the realisation of nulling interferometers with high star light suppression capability required to detect extrasolar planets, such as the one foreseen for the ESA Darwin mission. This paper presents the design, manufacturing, and test results of single mode fibres to be used as wavefront filters in mid-infrared range. Fibres made from chalcogenide glass and silver halide crystals were produced. The first class can serve as wavefront filters up to a wavelength of 11 microns, while silver halide fibres can be used over the full Darwin wavelength range from 6.5 to 18 micron. The chalcogenide glass fibres were drawn by double crucible method whereas polycrystalline fibres from silver halides were fabricated by multiple extrusion from a crystalline preform. Multi-layer AR-coatings for fibre ends were developed and environmentally tested for both types of fibres. Special fibre facet polishing procedures were established, in particular for the soft silver halide fibre ends. Cable design and assembly process were also developed, including termination by SMA-connectors with ceramic ferrules and fibre protection by loose PEEK-tubings to prevent excessive bending and chemical attacks for fibres. The wavefront filtering capability of the fibres was demonstrated on a high quality Mach-Zehnder interferometer. Two different groups of laser sources were used to measure the wavefront filtering of the fibres by using a CO-laser for testing in the lower sub-band and a CO2-laser to check the upper sub-band. Measurements of the fibres far field intensity distribution and transmission were performed for numerous cable samples. Single mode behaviour was observed in more than 25 silver halide fibre cables before AR-coating of their ends, while after that 17 cables were compliant with all technical requirements. Residual cladding modes existing in short single mode fibres were effectively removed by applying of a proper absorbing jacket to the fibre's lateral surface and by adding an oversized output aperture in front of fibre ends. Several fibres were exposed to gamma radiation of total dose of 25, 50, and even 500 krad. No deterioration was found on AR-coated fibre ends and on fibre material. Five fibres were irradiated by proton radiation of 10MeV energy and 1010 p/cm2 equivalent fluence. Several fibres were cooled down to 10 K by plunging them in a dipstick into liquid Helium. Silver halide fibres survived that test when cables were properly assembled. The brittle chalcogenide glass fibres were much more sensitive to thermal gradients and the related cables did not survive the thermal shock. Critical issues have been revealed in multiple drawings of chalcogenide glass fibres where core and cladding composition were not stable at some fabrication stages - resulting in a poor single mode guiding. Much better results have been achieved with polycrystalline fibres from silver halides made with a small core and low NA and enabling single mode guiding in the mid infrared.

An approach to knowledge structuring for advanced phases of the Technical and Management Information System (TMIS)

NASA Technical Reports Server (NTRS)

Goranson, H. T.

1986-01-01

The Technical and Management Information System (TMIS) must employ on enlightened approach to its object structure, but basic issues in conceptual structuring remain to be resolved. Sirius outlines the necessary agenda and reports on progress toward solutions.

48 CFR 752.7035 - Public notices.

Code of Federal Regulations, 2011 CFR

2011-10-01

... notices. The following clause is for use when the cognizant technical office determines that the contract... to time, to announce progress and accomplishments. Press releases or other public notices should... cognizant technical officer and to USAID's Legislative and Public Affairs (LPA) as far in advance of release...

14 CFR 1260.71 - Supplements and renewals.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., continued research relevance, and progress made by the recipient. (2) To insure uninterrupted programs, the technical office should forward to the grant office a completed award package, including a funded procurement request, technical evaluation of the proposed budget, and other support documentation, at least 29...

[A technical modification of the use of Dwyer's equipment].

PubMed

Carlioz, H; Damsin, J P

1991-01-01

Dwyer's technique for correction and anterior fusion of the spine was improved by using lockers at the level of each screw. So, like with the Zielke's technic this procedure allowed a global progressive and controllable correction and a real derotation of the spine.

A systematic assessment of the state of hazardous waste clean-up technologies. Quarterly technical progress report, April 1--June 30, 1993

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

Berg, M.T.; Reed, B.E.; Gabr, M.

1993-07-01

West Virginia University (WVU) and the US DOE Morgantown Energy Technology Center (METC) entered into a Cooperative Agreement on August 29, 1992 entitled ``Decontamination Systems Information and Research Programs.`` Stipulated within the Agreement is the requirement that WVU submit to METC a series of Technical Progress Report for Year 1 of the Agreement. This report reflects the progress and/or efforts performed on the following nine technical projects encompassed by the Year 1 Agreement for the period of April 1 through June 30, 1993: Systematic assessment of the state of hazardous waste clean-up technologies; site remediation technologies -- drain-enhanced soil flushingmore » (DESF) for organic contaminants removal; site remediation technologies -- in situ bioremediation of organic contaminants; excavation systems for hazardous waste sites; chemical destruction of polychlorinated biphenyls; development of organic sensors -- monolayer and multilayer self-assembled films for chemical sensors; Winfield lock and dam remediation; Assessments of Technologies for hazardous waste site remediation -- non-treatment technologies and pilot scale test facility implementation; and remediation of hazardous sites with stream reforming.« less

Progress, innovation and regulatory science in drug development: the politics of international standard-setting.

PubMed

Abraham, John; Reed, Tim

2002-06-01

This paper examines international standard-setting in the toxicology of pharmaceuticals during the 1990s, which has involved both the pharmaceutical industry and regulatory agencies in an organization known as the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH). The analysis shows that the relationships between innovation, regulatory science and 'progress' may be more complex and controversial than is often assumed. An assessment of the ICH's claims about the implications of 'technical' harmonization of drug-testing standards for the maintenance of drug safety, via toxicological testing, and the delivery of therapeutic progress, via innovation, is presented. By demonstrating that there is not a technoscientific validity for these claims, it is argued that, within the ICH, a discourse of technological innovation and scientific progress has been used by regulatory agencies and prominent parts of the transnational pharmaceutical industry to legitimize the lowering and loosening of toxicological standards for drug testing. The mobilization and acceptance of this discourse are shown to be pivotal to the ICH's transformation of reductions in safety standards, which are apparently against the interests of patients and public health, into supposed therapeutic benefits derived from promises of greater access to more innovative drug products. The evidence suggests that it is highly implausible that these reductions in the standards of regulatory toxicology are consistent with therapeutic progress for patients, and highlights a worrying aspect embedded in the 'technical trajectories' of regulatory science.

7 CFR 1944.541 - Reporting requirements.

Code of Federal Regulations, 2011 CFR

2011-01-01

...) PROGRAM REGULATIONS (CONTINUED) HOUSING Technical and Supervisory Assistance Grants § 1944.541 Reporting... District Director to determine satisfactory progress. The District Director will work with the grantee to... five working days of receipt. (1) If the reports indicate satisfactory progress, the State Director...

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

NASA Astrophysics Data System (ADS)

Leslie, Renee M.

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

Noble metal superparticles and methods of preparation thereof

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

Sun, Yugang; Hu, Yongxing

A method comprises heating an aqueous solution of colloidal silver particles. A soluble noble metal halide salt is added to the aqueous solution which undergoes a redox reaction on a surface of the silver particles to form noble metal/silver halide SPs, noble metal halide/silver halide SPs or noble metal oxide/silver halide SPs on the surface of the silver particles. The heat is maintained for a predetermined time to consume the silver particles and release the noble metal/silver halide SPs, the noble metal halide/silver halide SPs or the noble metal oxide/silver halide SPs into the aqueous solution. The aqueous solution ismore » cooled. The noble metal/silver halide SPs, the noble metal halide/silver halide SPs or noble metal oxide/silver halide SPs are separated from the aqueous solution. The method optionally includes adding a soluble halide salt to the aqueous solution.« less

The magnetohydrodynamics coal-fired flow facility

NASA Astrophysics Data System (ADS)

1995-01-01

In this quarterly technical progress report, UTSI reports on the status of a multitask contract to develop the technology for the steam bottoming portion of a MHD Steam Combined Cycle Power Plant. The report describes the facility maintenance and environmental work completed, status of completing technical reports and certain key administrative actions occurring during the quarter. With program resources at a minimum to closeout the MHD program, no further testing occurred during the quarter, but the DOE CFFF facility was maintained in a standby status with winterization, preventive maintenance and repairs accomplished as needed. Plans and preparations progressed for environmental actions needed at the site to investigate and characterize the groundwater and for removal/disposal of asbestos in the cooling tower. Work continued to progress on archiving the results of the MHD program.

GPHS-RTGs in support of the Cassini RTG Program

NASA Astrophysics Data System (ADS)

1995-04-01

The technical progress achieved during the period 26 Sep. 1994 - 2 Apr. 1995 on Contract DE-AC03-91SF-18852 Radioisotope Thermoelectric Generators and Ancillary Activities is described herein. Monthly technical activity for the period 27 Feb. - 2 Apr. 1995 is included in this progress report. The report addresses tasks, including: spacecraft integration and liaison; engineering support; safety; qualified unicouple production; ETG fabrication, assembly, and test; ground support equipment; RTG shipping and launch support; designs, reviews, and mission applications; project management, quality assurance, reliability, contract changes, CAGO acquisition (operating funds), and CAGO maintenance and repair; and CAGO acquisition (capital funds).

The Gap That Can't Go Away: The Catch-22 of Reclassification in Monitoring the Progress of English Learners

ERIC Educational Resources Information Center

Saunders, William M.; Marcelletti, David J.

2013-01-01

When English Learners (ELs) demonstrate English language proficiency, they are reclassified as Fluent English Proficient (RFEP). Subsequently they are often left out of the analysis of EL progress because they are, technically, no longer ELs. This article examines the effects of including and excluding RFEPs from the analysis of EL progress. Based…

Bone Conduction Communication: Research Progress and Directions

DTIC Science & Technology

2017-08-16

ARL-TR-8096 ● AUG 2017 US Army Research Laboratory Bone Conduction Communication: Research Progress and Directions by Maranda...this report when it is no longer needed. Do not return it to the originator. ARL-TR-8096 ● AUG 2017 US Army Research Laboratory...Bone Conduction Communication: Research Progress and Directions by Maranda McBride North Carolina Agricultural and Technical State University

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

25 CFR 30.123 - What is the Bureau's role in assisting Bureau-funded schools to make AYP?

Code of Federal Regulations, 2010 CFR

2010-04-01

... EDUCATION ADEQUATE YEARLY PROGRESS Failure To Make Adequate Yearly Progress § 30.123 What is the Bureau's...-funded schools to assist them in achieving AYP. This includes technical assistance and other forms of...

25 CFR 30.123 - What is the Bureau's role in assisting Bureau-funded schools to make AYP?

Code of Federal Regulations, 2011 CFR

2011-04-01

... EDUCATION ADEQUATE YEARLY PROGRESS Failure To Make Adequate Yearly Progress § 30.123 What is the Bureau's...-funded schools to assist them in achieving AYP. This includes technical assistance and other forms of...

The Empirical Formula of Silver Sulfide: An Experiment for Introductory Chemistry

ERIC Educational Resources Information Center

Trujillo, Carlos Alexander

2007-01-01

An experiment is described that allows students to experimentally determine an empirical formula for silver sulfide. At elevated temperatures, silver sulfide reacts in air to form silver, silver sulfate, and sulfur dioxide. At higher temperatures (960 [degree]C) silver sulfate decomposes to produce metallic silver. (Contains 1 figure and 1 table.)

Factors influencing the preparation of silver-coated glass frit with polyvinyl-pyrrolidone

NASA Astrophysics Data System (ADS)

Xiang, Feng; Gan, Weiping

2018-01-01

In this work, a new electroless silver plating method for the synthesis of silver-coated glass frit composite powders with good morphology has been proposed and the polyvinyl-pyrrolidone (PVP) was used the activating agent. It was found that the weight ratio of PVP to glass frit affected the distribution and number of silver nanoparticles. Moreover, the loading capacity of the glass frit, the pH value and reaction temperature could influence the size of the silver nanoparticles and morphology of silver on the surface of glass frit. The as-prepared silver-coated glass frit was used to prepare a silver paste using an optimized process to form silver nanoparticles with uniform size and high density. The silver paste with silver-coated glass frit increased the photovoltaic conversion efficiency of silicon solar cells by 0.271% compared with the silver paste prepared with pure glass frit. The silver nanoparticles can promoted the precipitation of Ag crystallites on the silicon wafer. Therefore, the silver-coated glass frit can further optimize and enhance the electrical performance of solar cells.

Black River Technical College, Exploring America's Communities. Progress Report.

ERIC Educational Resources Information Center

Black River Vocational-Technical School, Pocahontas, AR.

In 1996, Arkansas's Black River Technical College (BRTC) participated in the American Association of Community Colleges' Exploring America's Communities project, which worked to strengthen the teaching and learning of American history, literature, and culture at U.S. community colleges. The proposed centerpiece of BRTC's program is called the…

40 CFR 40.150 - Evaluation of applications.

Code of Federal Regulations, 2011 CFR

2011-07-01

.... Relevancy, coupled with the results of technical review, will provide the basis for funding recommendations... will be reviewed for technical merit by at least one reviewer within EPA and at least two reviewers.... Recommendations for continuation of funding will be based on progress toward the accomplishment of the goals set...

40 CFR 35.4235 - Are there specific provisions my group's contract(s) must contain?

Code of Federal Regulations, 2011 CFR

2011-07-01

... PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Grants for Technical Assistance Procuring A Technical Advisor Or Other Contractor with Tag Funds § 35.4235 Are there specific... progress reports; (3) Expenditures; and (4) Commitments indicating their relationship to established costs...

Missouri local technical assistance program at Missouri University of Science and Technology (formerly University of Missouri--Rolla) : annual progress report January-December 2007.

DOT National Transportation Integrated Search

2009-02-01

This annual report is a summary of the activities during 2007 for the Missouri Local Technical Assistance Program (Missouri LTAP), which is located at Missouri University of Science and Technology. The report highlights Missouri LTAPs performance ...

Global Issues in Career and Technical Fields: Internationalizing the Community College Curriculum.

ERIC Educational Resources Information Center

Peck, Shirley S.

1991-01-01

Presents a rationale for incorporating international content in both general education and career/technical fields, providing a status report on progress to date. Describes four modules prepared by Catonsville Community College (Maryland) instructors for inclusion in criminal justice, air transportation, automotive service, and electronics…

Technical and Vocational Education in Cameroon and Critical Avenues for Development

ERIC Educational Resources Information Center

Che, S. Megan

2007-01-01

Technical and vocational education (TVE) can influence development and economic progress for post-colonial societies. Some newly independent sub-Saharan African countries attempted curricular transformation that might produce a skilled workforce through widespread access to versions of TVE. In Cameroon, no such post-colonial curricular revolution…

Method for the recovery of silver from silver zeolite

DOEpatents

Reimann, G.A.

1985-03-05

High purity silver is recovered from silver exchanged zeolite used to capture radioactive iodine from nuclear reactor and nuclear fuel reprocessing environments. The silver exchanged zeolite is heated with slag formers to melt and fluidize the zeolite and release the silver, the radioactivity removing with the slag. The silver containing metallic impurities is remelted and treated with oxygen and a flux to remove the metal impurities. About 98% of the silver in the silver exchanged zeolite having a purity of 99% or better is recoverable by the method.

Method for the recovery of silver from silver zeolite

DOEpatents

Reimann, George A.

1986-01-01

High purity silver is recovered from silver exchanged zeolite used to capture radioactive iodine from nuclear reactor and nuclear fuel reprocessing environments. The silver exchanged zeolite is heated with slag formers to melt and fluidize the zeolite and release the silver, the radioactivity removing with the slag. The silver containing metallic impurities is remelted and treated with oxygen and a flux to remove the metal impurities. About 98% of the silver in the silver exchanged zeolite having a purity of 99% or better is recoverable by the method.

Glass frits coated with silver nanoparticles for silicon solar cells

NASA Astrophysics Data System (ADS)

Li, Yingfen; Gan, Weiping; Zhou, Jian; Li, Biyuan

2015-06-01

Glass frits coated with silver nanoparticles were prepared by electroless plating. Gum Arabic (GA) was used as the activating agent of glass frits without the assistance of stannous chloride or palladium chloride. The silver-coated glass frits prepared with different GA dosages were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and thermogravimetric analysis (TGA). The characterization results indicated that silver-coated glass frits had the structures of both glass and silver. Spherical silver nanoparticles were distributed on the glass frits evenly. The density and particle size of silver nanoparticles on the glass frits can be controlled by adjusting the GA dosage. The silver-coated glass frits were applied to silver pastes to act as both the densification promoter and silver crystallite formation aid in the silver electrodes. The prepared silver-coated glass frits can improve the photovoltaic performances of solar cells.

Publications of the Jet Propulsion Laboratory, January through December 1974. [deep space network, Apollo project, information theory, and space exploration

NASA Technical Reports Server (NTRS)

1975-01-01

Formalized technical reporting is described and indexed, which resulted from scientific and engineering work performed, or managed, by the Jet Propulsion Laboratory. The five classes of publications included are technical reports, technical memorandums, articles from the bimonthly Deep Space Network Progress Report, special publications, and articles published in the open literature. The publications are indexed by author, subject, and publication type and number.

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.…

Technical adequacy of growth estimates from a computer adaptive test: Implications for progress monitoring.

PubMed

Van Norman, Ethan R; Nelson, Peter M; Parker, David C

2017-09-01

Computer adaptive tests (CATs) hold promise to monitor student progress within multitiered systems of support. However, the relationship between how long and how often data are collected and the technical adequacy of growth estimates from CATs has not been explored. Given CAT administration times, it is important to identify optimal data collection schedules to minimize missed instructional time. We used simulation methodology to investigate how the duration and frequency of data collection influenced the reliability, validity, and precision of growth estimates from a math CAT. A progress monitoring dataset of 746 Grade 4, 664 Grade 5, and 400 Grade 6 students from 40 schools in the upper Midwest was used to generate model parameters. Across grades, 53% of students were female and 53% were White. Grade level was not as influential as the duration and frequency of data collection on the technical adequacy of growth estimates. Low-stakes decisions were possible after 14-18 weeks when data were collected weekly (420-540 min of assessment), 20-24 weeks when collected every other week (300-360 min of assessment), and 20-28 weeks (150-210 min of assessment) when data were collected once a month, depending on student grade level. The validity and precision of growth estimates improved when the duration and frequency of progress monitoring increased. Given the amount of time required to obtain technically adequate growth estimates in the present study, results highlight the importance of weighing the potential costs of missed instructional time relative to other types of assessments, such as curriculum-based measures. Implications for practice, research, as well as future directions are also discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

24 CFR 1006.430 - Corrective and remedial action.

Code of Federal Regulations, 2011 CFR

2011-04-01

... plan; (3) Made substantial progress in carrying out its program and achieving its quantifiable goals as... to submit progress schedules for completing activities or complying with the requirements of the Act... appropriate technical assistance using existing grant funds or other available resources to overcome the...

Process for making silver metal filaments

DOEpatents

Bamberger, Carlos E.

1997-01-01

A process for making silver metal particles from silver salt particles having the same morphology. Precursor silver salt particles selected from the group consisting of silver acetate and silver sulfide having a selected morphology are contained in a reactor vessel having means for supporting the particles in an air suspension to prevent the agglomeration of the particles. Air is flowed through the reactor vessel at a flow rate sufficient to suspend the particles in the reactor vessel. The suspended precursor silver salt particles are heated to a processing temperature and at a heating rate below which the physical deterioration of the suspended precursor silver salt particles takes place. The suspended precursor silver salt particles are maintained at the processing temperature for a period of time sufficient to convert the particles into silver metal particles having the same morphology as the precursor silver salt particles.

Room temperature synthesis of silver nanowires from tabular silver bromide crystals in the presence of gelatin

NASA Astrophysics Data System (ADS)

Liu, Suwen; Wehmschulte, Rudolf J.; Lian, Guoda; Burba, Christopher M.

2006-03-01

Long silver nanowires were synthesized at room temperature by a simple and fast process derived from the development of photographic films. A film consisting of an emulsion of tabular silver bromide grains in gelatin was treated with a photographic developer (4-(methylamino)phenol sulfate (metol), citric acid) in the presence of additional aqueous silver nitrate. The silver nanowires have lengths of more than 50 μm, some even more than 100 μm, and average diameters of about 80 nm. Approximately, 70% of the metallic silver formed in the reduction consists of silver nanowires. Selected area electron diffraction (SAED) results indicate that the silver nanowires grow along the [111] direction. It was found that the presence of gelatin, tabular silver bromide crystals and silver ions in solution are essential for the formation of the silver nanowires. The nanowires appear to originate from the edges of the silver bromide crystals. They were characterized by transmission electron microscopy (TEM), SAED, scanning electron microscopy (SEM), and powder X-ray diffraction (XRD).

Antibacterial activity and toxicity of silver - nanosilver versus ionic silver

NASA Astrophysics Data System (ADS)

Kvitek, L.; Panacek, A.; Prucek, R.; Soukupova, J.; Vanickova, M.; Kolar, M.; Zboril, R.

2011-07-01

The in vitro study of antibacterial activity of silver nanoparticles (NPs), prepared via modified Tollens process, revealed high antibacterial activity even at very low concentrations around several units of mg/L. These concentrations are comparable with concentrations of ionic silver revealing same antibacterial effect. However, such low concentrations of silver NPs did not show acute cytotoxicity to mammalian cells - this occurs at concentrations higher than 60 mg/L of silver, while the cytotoxic level of ionic silver is much more lower (approx. 1 mg/L). Moreover, the silver NPs exhibit lower acute ecotoxicity against the eukaryotic organisms such as Paramecium caudatum, Monoraphidium sp. and D. melanogaster. The silver NPs are toxic to these organisms at the concentrations higher than 30 mg/L of silver. On contrary, ionic silver retains its cytoxicity and ecotoxicity even at the concentration equal to 1 mg/L. The performed experiments demonstrate significantly lower toxicity of silver NPs against the eukaryotic organisms than against the prokaryotic organisms.

Separation of silver ions and starch modified silver nanoparticles using high performance liquid chromatography with ultraviolet and inductively coupled mass spectrometric detection

NASA Astrophysics Data System (ADS)

Hanley, Traci A.; Saadawi, Ryan; Zhang, Peng; Caruso, Joseph A.; Landero-Figueroa, Julio

2014-10-01

The production of commercially available products marketed to contain silver nanoparticles is rapidly increasing. Species-specific toxicity is a phenomenon associated with many elements, including silver, making it imperative to develop a method to identify and quantify the various forms of silver (namely, silver ions vs. silver nanoparticles) possibly present in these products. In this study a method was developed using high performance liquid chromatography (HPLC) with ultraviolet (UV-VIS) and inductively coupled mass spectrometric (ICP-MS) detection to separate starch stabilized silver nanoparticles (AgNPs) and silver ions (Ag+) by cation exchange chromatography with 0.5 M nitric acid mobile phase. The silver nanoparticles and ions were baseline resolved with an ICP-MS response linear over four orders of magnitude, 0.04 mg kg- 1 detection limit, and 90% chromatographic recovery for silver solutions containing ions and starch stabilized silver nanoparticles smaller than 100 nm.

Progress and Prospect: A Report Submitted to the Governing Board of the Maricopa County Community College District.

ERIC Educational Resources Information Center

Maricopa Technical Community Coll., Phoenix, AZ.

This two-part report seeks to outline the progress made to date by Maricopa Technical Community College (MTCC) through its first eight years of operation, and to recommend specific actions which might be taken in the future by the college to insure its continued progress and response to community needs in light of constraints on funding and…

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

Bone Loss at Implant with Titanium Abutments Coated by Soda Lime Glass Containing Silver Nanoparticles: A Histological Study in the Dog

PubMed Central

Martinez, Arturo; Guitián, Francisco; López-Píriz, Roberto; Bartolomé, José F.; Cabal, Belén; Esteban-Tejeda, Leticia; Torrecillas, Ramón; Moya, José S.

2014-01-01

The aim of the present study was to evaluate bone loss at implants connected to abutments coated with a soda-lime glass containing silver nanoparticles, subjected to experimental peri-implantitis. Also the aging and erosion of the coating in mouth was studied. Five beagle dogs were used in the experiments. Three implants were placed in each mandible quadrant: in 2 of them, Glass/n-Ag coated abutments were connected to implant platform, 1 was covered with a Ti-mechanized abutment. Experimental peri-implantitis was induced in all implants after the submarginal placement of cotton ligatures, and three months after animals were euthanatized. Thickness and morphology of coating was studied in abutment cross-sections by SEM. Histology and histo-morphometric studies were carried on in undecalfied ground slides. After the induced peri-implantitis: 1.The abutment coating shown losing of thickness and cracking. 2. The histometry showed a significant less bone loss in the implants with glass/n-Ag coated abutments. A more symmetric cone of bone resorption was observed in the coated group. There were no significant differences in the peri-implantitis histological characteristics between both groups of implants. Within the limits of this in-vivo study, it could be affirmed that abutments coated with biocide soda-lime-glass-silver nanoparticles can reduce bone loss in experimental peri-implantitis. This achievement makes this coating a suggestive material to control peri-implantitis development and progression. PMID:24466292

Long life, low cost, rechargeable AgZn battery for non-military applications

NASA Astrophysics Data System (ADS)

Brown, Curtis C.

1996-03-01

Of the rechargeable (secondary) battery systems with mature technology, the silver oxide-zinc system (AgZn) safely offers the highest power and energy (watts and watt hours) per unit of volume and mass. As a result they have long been used for aerospace and defense applications where they have also proven their high reliability. In the past, the expense associated with the cost of silver and the resulting low production volume have limited their commercial application. However, the relative low cost of silver now make this system feasible in many applications where high energy and reliability are required. One area of commercial potential is power for a new generation of sophisticated, portable medical equipment. AgZn batteries have recently proven ``enabling technology'' for power critical, advanced medical devices. By extending the cycle calendar life to the system (offers both improved performance and lower operating cost), a combination is achieved which may enable a wide range of future electrical devices. Other areas where AgZn batteries have been used in nonmilitary applications to provide power to aid in the development of commercial equipment have been: (a) Electrically powered vehicles; (b) Remote sensing in nuclear facilities; (c) Special effects equipment for movies; (d) Remote sensing in petroleum pipe lines; (e) Portable computers; (f) Fly by wire systems for commercial aircraft; and (g) Robotics. However none of these applications have progressed to the level where the volume required will significantly lower cost.

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.

Optical fiber sensors for materials and structures characterization

NASA Technical Reports Server (NTRS)

Lindner, D. K.; Claus, R. O.

1991-01-01

The final technical report on Optical Fiber Sensors for Materials and Structures Characterization, covering the period August 1990 through August 1991 is presented. Research programs in the following technical areas are described; sapphire optical fiber sensors; vibration analysis using two-mode elliptical core fibers and sensors; extrinsic Fabry-Perot interferometer development; and coatings for fluorescent-based sensor. Research progress in each of these areas was substantial, as evidenced by the technical publications which are included as appendices.

44 CFR 206.437 - State administrative plan.

Code of Federal Regulations, 2010 CFR

2010-10-01

... requests for advances of funds and reimbursement; (vii) Monitor and evaluate the progress and completion of... technical assistance as required to subgrantee(s); (xi) Comply with the administrative and audit requirements of 44 CFR parts 13 and 206; (xii) Provide quarterly progress reports to the Regional Administrator...

25 CFR 30.122 - Must the Bureau assist a school it identified for school improvement, corrective action, or...

Code of Federal Regulations, 2010 CFR

2010-04-01

..., DEPARTMENT OF THE INTERIOR EDUCATION ADEQUATE YEARLY PROGRESS Failure To Make Adequate Yearly Progress § 30... restructuring, the Bureau must provide technical or other assistance described in 20 U.S.C. 6316(b)(4) and 20 U...

44 CFR 206.437 - State administrative plan.

Code of Federal Regulations, 2011 CFR

2011-10-01

... requests for advances of funds and reimbursement; (vii) Monitor and evaluate the progress and completion of... technical assistance as required to subgrantee(s); (xi) Comply with the administrative and audit requirements of 44 CFR parts 13 and 206; (xii) Provide quarterly progress reports to the Regional Administrator...

25 CFR 30.122 - Must the Bureau assist a school it identified for school improvement, corrective action, or...

Code of Federal Regulations, 2011 CFR

2011-04-01

..., DEPARTMENT OF THE INTERIOR EDUCATION ADEQUATE YEARLY PROGRESS Failure To Make Adequate Yearly Progress § 30... restructuring, the Bureau must provide technical or other assistance described in 20 U.S.C. 6316(b)(4) and 20 U...

Assessment Program Technical Progress Report, 1997-1998.

ERIC Educational Resources Information Center

Eickmeyer, Barbara; Hill, Stephen

This Assessment Program Progress Report (APPR) records the institutional activities that have taken place at Coconino Community College (CCC) during the 1997-98 academic year. It presents models, timelines, accomplishments, and opportunities for improvement in the assessment practices at CCC. Implementation and outcomes information is included for…

Diagnostic Efficiency of easyCBM[R] Math: Oregon. Technical Report #1009

ERIC Educational Resources Information Center

Anderson, Daniel; Alonzo, Julie; Tindal, Gerald

2010-01-01

The easyCBM[R] assessment system is an online benchmark and progress monitoring assessment system designed for use within a response to intervention framework. Educators using easyCBM[R] are often interested in using the results to predict students' state test performance. In the following technical document, we report diagnostic efficiency…

Longitudinal Surveys of Australian Youth (LSAY) 2009 Cohort: Wave 2 (2010)-- Questionnaire. Technical Report 71A

ERIC Educational Resources Information Center

National Centre for Vocational Education Research (NCVER), 2012

2012-01-01

The Longitudinal Surveys of Australian Youth (LSAY) program studies the progress of several groups of young Australians as they move from school into post-secondary education and work. This technical paper contains the questionnaire for the LSAY 2009 cohort Wave 2 (2010) data set.

Longitudinal Surveys of Australian Youth (LSAY) 2009 Cohort: Wave 3 (2011)--Questionnaire. Technical Report 72A

ERIC Educational Resources Information Center

National Centre for Vocational Education Research (NCVER), 2012

2012-01-01

The Longitudinal Surveys of Australian Youth (LSAY) program studies the progress of several groups of young Australians as they move from school into post-secondary education and work. This technical paper contains the questionnaire for the LSAY 2009 cohort Wave 3 (2011) data set.

Educational Reform and the World of Work: Italy

ERIC Educational Resources Information Center

von Blumenthal, Viktor

1977-01-01

One of a four-issue series on educational reform and the world of work in Europe, this issue discusses educational planning and secondary school reform in Italy. Topics discussed include planning and research in vocational-technical education, and the relation between acquisition of specific skills and scientific and technical progress. (Author/DB)

Longitudinal Surveys of Australian Youth (LSAY) 2009 Cohort: Wave 2 (2010)--Frequency Tables. Technical Report 71B

ERIC Educational Resources Information Center

National Centre for Vocational Education Research (NCVER), 2012

2012-01-01

The Longitudinal Surveys of Australian Youth (LSAY) program studies the progress of several groups of young Australians as they move from school into post-secondary education and work. This technical paper contains the frequency tables for the LSAY 2009 cohort Wave 2 (2010) data set.

Higher Education in Kazakhstan and the Bologna Process

ERIC Educational Resources Information Center

Piven, G.; Pak, I.U.

2006-01-01

The constantly rising role of higher education in the twenty-first century goes hand in hand with scientific and technical progress and the global technologization of the developed countries of the world. A country's level of technical and technological development determines its economic condition, its national security, and its role in the world…

A State Response to Indian Vocational Education.

ERIC Educational Resources Information Center

McConnell, Bruce

In 1977 more than 500 Native Americans attended Wisconsin's vocational, technical and adult schools located in the state's 16 vocational-technical districts. While many problems still lack a clear identification and many new programs are needed to meet the needs of Native Americans, a great deal of progress has been made. A group of four Indians…

Analytical Chemistry Division. Annual progress report for period ending December 31, 1980

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

Lyon, W.S.

1981-05-01

This report is divided into: analytical methodology; mass and emission spectrometry; technical support; bio/organic analysis; nuclear and radiochemical analysis; quality assurance, safety, and tabulation of analyses; supplementary activities; and presentation of research results. Separate abstracts were prepared for the technical support, bio/organic analysis, and nuclear and radiochemical analysis. (DLC)

Scientific and Technical Information Transfer for Education (STITE). Research Report No. 2.

ERIC Educational Resources Information Center

Zunde, Pranas

STITE (Scientific and Technical Information Transfer for Education) is basically a system to interface between science information and the science learner. As such STITE acts as a link between STIC (Science and Technology Infromation Centers) and LIS (Learning Information Systems). In this second progress report the internal knowledge of STITE is…

Mathematics Technical Report: Exercise Volume. National Assessment of Educational Progress. Report No. 04-MA-20.

ERIC Educational Resources Information Center

Education Commission of the States, Denver, CO. National Assessment of Educational Progress.

Included in Chapter 1 of this report are background information on the 1972-73 mathematics assessment; details of the computational formulas used in reporting results; and explanations of the technical documentation, exercise presentation, documentation pages, scoring guides, and data tables for released and unreleased exercises. The remainder of…

Experimentation with Computer-Assisted Instruction in Technical Education. Semi-Annual Progress Report.

ERIC Educational Resources Information Center

Mitzel, Harold E.; Brandon, George L.

A series of five reports is presented which describes the activities carried out by the Pennsylvania State University group engaged in research in computer-assisted instruction (CAI) in vocational-technical education. The reports cover the period January 1968-June 1968 and deal with: 1) prior knowledge and individualized instruction; 2) numerical…

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...

Do failures in non-technical skills contribute to fatal medical accidents in Japan? A review of the 2010–2013 national accident reports

PubMed Central

Uramatsu, Masashi; Fujisawa, Yoshikazu; Mizuno, Shinya; Souma, Takahiro; Komatsubara, Akinori; Miki, Tamotsu

2017-01-01

Objectives We sought to clarify how large a proportion of fatal medical accidents can be considered to be caused by poor non-technical skills, and to support development of a policy to reduce number of such accidents by making recommendations about possible training requirements. Design Summaries of reports of fatal medical accidents, published by the Japan Medical Safety Research Organization, were reviewed individually. Three experienced clinicians and one patient safety expert conducted the reviews to determine the cause of death. Views of the patient safety expert were given additional weight in the overall determination. Setting A total of 73 summary reports of fatal medical accidents were reviewed. These reports had been submitted by healthcare organisations across Japan to the Japan Medical Safety Research Organization between April 2010 and March 2013. Primary and secondary outcome measures The cause of death in fatal medical accidents, categorised into technical skills, non-technical skills and inevitable progress of disease were evaluated. Non-technical skills were further subdivided into situation awareness, decision making, communication, team working, leadership, managing stress and coping with fatigue. Results Overall, the cause of death was identified as non-technical skills in 34 cases (46.6%), disease progression in 33 cases (45.2%) and technical skills in two cases (5.5%). In two cases, no consensual determination could be achieved. Further categorisation of cases of non-technical skills were identified as 14 cases (41.2%) of problems with situation awareness, eight (23.5%) with team working and three (8.8%) with decision making. These three subcategories, or combinations of them, were identified as the cause of death in 33 cases (97.1%). Conclusions Poor non-technical skills were considered to be a significant cause of adverse events in nearly half of the fatal medical accidents examined. Improving non-technical skills may be effective for reducing accidents, and training in particular subcategories of non-technical skills may be especially relevant. PMID:28209605

Cost-effectiveness Analysis of Silver Delivery Approaches in the Management of Partial-thickness Burns.

PubMed

Nherera, Leo; Trueman, Paul; Roberts, Christopher; Berg, Leena

2018-02-23

Burn injury is a common type of traumatic injury that causes considerable morbidity and mortality, resulting in about 30,000 admissions annually in specialist burn centers and costing around $1 billion per year in the United States. One percent silver sulfadiazine has been utilized widely in the management of burns and newer silver dressings are on the market, including nanocrystalline silver dressings, silver-impregnated hydrofiber dressings, and silver-impregnated foam dressings. This study sought to determine the cost effectiveness of the newer silver dressings using clinical data from an indirect treatment comparison using silver sulfadiazine as the baseline. A decision analytic model was developed from a US payer's perspective for burn patients with a total body surface area of < 20%. Outcomes were length of stay, infections and incidence of surgical procedures, quality adjusted life years (QALYs), and cost. The meta-analysis reported a statistically significant reduction in length of hospital stay and clinically important reductions in infections and incidence of surgical procedures in favor of the silver barrier dressing compared with other silver dressings. The estimated QALYs were 0.970 versus 0.969 versus 0.969 and mean cost per patient was $15,892, $23,799, and $24,269 for the nanocrystalline silver dressing, silver-impregnated hydrofiber dressing, and silver-impregnated foam dressing, respectively. The analysis showed the nanocrystalline silver dressing to be a dominant strategy (less costly with better outcomes). These findings were robust to a range of sensitivity analyses. According to data from an indirect treatment comparison, this analysis suggests that nanocrystalline silver dressing is the most cost-effective silver delivery system. Prospective head-to-head research on the costs and outcomes of these silver delivery systems in this patient population is necessary to validate the results of this economic evaluation.

Physicochemical properties of protein-modified silver nanoparticles in seawater

NASA Astrophysics Data System (ADS)

Zhong, Hangyue

2013-10-01

This study investigated the physicochemical properties of silver nanoparticles stabilized with casein protein in seawater. UV?vis spectrometry, dynamic light scattering (DLS), and transmission electron microscopy (TEM) were applied to measure the stability of silver nanoparticles in seawater samples. The obtained results show an increased aggregation tendency of silver nanoparticles in seawater, which could be attributed its relatively high cation concentration that could neutralize the negatively charges adsorbed on the surface of silver nanoparticles and reduce the electrostatic repulsion forces between nanoparticles. Similarly, due to the surface charge screening process, the zeta potential of silver nanoparticles in seawater decreased. This observation further supported the aggregation behavior of silver nanoparticles. This study also investigated the dissolution of silver nanoparticles in seawater. Result shows that the silver nanoparticle dissolution in DI water is lower than in seawater, which is attributed to the high Cl? concentration present in seawater. As Cl? can react with silver and form soluble AgCl complex, dissolution of silver nanoparticles was enhanced. Finally, this study demonstrated that silver nanoparticles are destabilized in seawater condition. These results may be helpful in understanding the environmental risk of discharged silver nanoparticles in seawater conditions.

International Energy: Subject Thesaurus. Revision 1

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

Not Available

The International Energy Agency: Subject Thesaurus contains the standard vocabulary of indexing terms (descriptors) developed and structured to build and maintain energy information databases. Involved in this cooperative task are (1) the technical staff of the USDOE Office of Scientific and Technical Information (OSTI) in cooperation with the member countries of the International Energy Agency`s Energy Technology Data Exchange (ETDE) and (2) the International Atomic Energy Agency`s International Nuclear Information System (INIS) staff representing the more than 100 countries and organizations that record and index information for the international nuclear information community. ETDE member countries are also members of INIS.more » Nuclear information prepared for INIS by ETDE member countries is included in the ETDE Energy Database, which contains the online equivalent of the printed INIS Atomindex. Indexing terminology is therefore cooperatively standardized for use in both information systems. This structured vocabulary reflects thscope of international energy research, development, and technological programs. The terminology of this thesaurus aids in subject searching on commercial systems, such as ``Energy Science & Technology`` by DIALOG Information Services, ``Energy`` by STN International and the ``ETDE Energy Database`` by SilverPlatter. It is also the thesaurus for the Integrated Technical Information System (ITIS) online databases of the US Department of Energy.« less

Silver in medicine: a brief history BC 335 to present.

PubMed

Barillo, David J; Marx, David E

2014-12-01

Silver is a naturally occurring element. Similar to other metals, the ionized form of silver (Ag(+1)) has known antimicrobial properties. A number of wound dressings incorporating silver ion or silver compounds have recently been developed and marketed. In addition, the antimicrobial effects of silver are currently being promoted in consumer products such as clothing and household appliances. The present use of silver in medical and consumer products has prompted concerns for potential toxicity and ecological effects, including induction of microbial resistance to antibiotics. These concerns ignore the fact that silver has been used for medicinal purposes for several thousand years. A historical review of the uses of silver in medicine is presented.

The Electrodeposition of Silver from Supercritical Carbon Dioxide/Acetonitrile

PubMed Central

Bartlett, Philip N; Perdjon-Abel, Magdalena; Cook, David; Reid, Gillian; Levason, William; Cheng, Fei; Zhang, Wenjian; George, Michael W; Ke, Jie; Beanland, Richard; Sloan, Jeremy

2014-01-01

Cyclic voltammetry of silver coordination complexes in acetonitrile and in a single-phase supercritical carbon dioxide/acetonitrile (scCO2/CH3CN) system is reported. Five silver precursors are investigated: (1,5-cyclooctadiene)(hexafluoroacetylacetonato) silver(I) [Ag(hfac)(COD)], (hexafluoroacetylacetonato)(triphenylphosphine) silver(I) [Ag(hfac)(PPh3)], (perfluorooctanoato)bis(triphenylphosphine) silver(I) [Ag(CF3(CF2)6CO2)(PPh3)2], tetrakis(triphenylphosphine) silver(I) tetrafluoroborate [Ag(PPh3)4][BF4] and tetrakis(acetonitrile) silver(I) tetrafluoroborate [Ag(CH3CN)4][BF4]. Of these, [Ag(CH3CN)4][BF4] is found to be the most suitable for electrodeposition of silver from scCO2/CH3CN.

Room temperature synthesis of silver nanowires from tabular silver bromide crystals in the presence of gelatin

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

Liu Suwen; Wehmschulte, Rudolf J.; Lian Guoda

2006-03-15

Long silver nanowires were synthesized at room temperature by a simple and fast process derived from the development of photographic films. A film consisting of an emulsion of tabular silver bromide grains in gelatin was treated with a photographic developer (4-(methylamino)phenol sulfate (metol), citric acid) in the presence of additional aqueous silver nitrate. The silver nanowires have lengths of more than 50 {mu}m, some even more than 100 {mu}m, and average diameters of about 80 nm. Approximately, 70% of the metallic silver formed in the reduction consists of silver nanowires. Selected area electron diffraction (SAED) results indicate that the silvermore » nanowires grow along the [111] direction. It was found that the presence of gelatin, tabular silver bromide crystals and silver ions in solution are essential for the formation of the silver nanowires. The nanowires appear to originate from the edges of the silver bromide crystals. They were characterized by transmission electron microscopy (TEM), SAED, scanning electron microscopy (SEM), and powder X-ray diffraction (XRD)« less

A review of the antibacterial effects of silver nanomaterials and potential implications for human health and the environment

NASA Astrophysics Data System (ADS)

Marambio-Jones, Catalina; Hoek, Eric M. V.

2010-06-01

Here, we present a review of the antibacterial effects of silver nanomaterials, including proposed antibacterial mechanisms and possible toxicity to higher organisms. For purpose of this review, silver nanomaterials include silver nanoparticles, stabilized silver salts, silver-dendrimer, polymer and metal oxide composites, and silver-impregnated zeolite and activated carbon materials. While there is some evidence that silver nanoparticles can directly damage bacteria cell membranes, silver nanomaterials appear to exert bacteriocidal activity predominantly through release of silver ions followed (individually or in combination) by increased membrane permeability, loss of the proton motive force, inducing de-energization of the cells and efflux of phosphate, leakage of cellular content, and disruption DNA replication. Eukaryotic cells could be similarly impacted by most of these mechanisms and, indeed, a small but growing body of literature supports this concern. Most antimicrobial studies are performed in simple aquatic media or cell culture media without proper characterization of silver nanomaterial stability (aggregation, dissolution, and re-precipitation). Silver nanoparticle stability is governed by particle size, shape, and capping agents as well as solution pH, ionic strength, specific ions and ligands, and organic macromolecules—all of which influence silver nanoparticle stability and bioavailability. Although none of the studies reviewed definitively proved any immediate impacts to human health or the environment by a silver nanomaterial containing product, the entirety of the science reviewed suggests some caution and further research are warranted given the already widespread and rapidly growing use of silver nanomaterials.

Migration of silver from commercial plastic food containers and implications for consumer exposure assessment.

PubMed

von Goetz, Natalie; Fabricius, Lars; Glaus, Reto; Weitbrecht, Volker; Günther, Detlef; Hungerbühler, Konrad

2013-01-01

Food storage containers with embedded silver as an antibacterial agent promise longer durability of food. For risk assessment the release of this silver into the stored food and resulting human exposure need to be known. For the purpose of exposure assessment, silver migration from commercial plastic containers with declared content of 'nano-' or 'micro-silver' into different food simulants (water, 10% ethanol, 3% acetic acid, olive oil) was quantitatively determined by ICP-MS and the form of the released silver was investigated. The highest migration of silver was observed for the acidic food simulant with 30 ng silver cm(-2) contact surface within 10 days at 20°C. In a second and third use cycle, migration dropped by a factor of up to 10, so that the maximum cumulated release over three use cycles was 34 ng cm(-2). The silver release over time was described using a power function and a numerical model that simulates Fickian diffusion through the plastic material. The released silver was found to be in ionic form, but also in the form of silver nanoparticles (around 12%). Consumer exposure to the total amount of silver released from the food containers is low in comparison with the background silver exposure of the general population, but since natural background concentrations are only known for ionic silver, the exposure to silver nanoparticles is not directly comparable with a safe background level.

Multifaceted prismatic silver nanoparticles: synthesis by chloride-directed selective growth from thiolate-protected clusters and SERS properties.

PubMed

Cathcart, Nicole; Kitaev, Vladimir

2012-11-21

We describe the synthetic preparation of well-defined symmetric multifaceted prismatic silver nanoparticles with chemically controlled faceting advantageous for strong and tunable surface-enhanced Raman scattering, SERS. These silver nanoparticles, that have been termed nanoflowers, AgNFls for their characteristic morphologies, have been prepared by a one-pot aqueous reaction under ambient conditions. AgNFl faceting is synthetically controlled by selective nanoparticle growth driven by chloride ions. Selective chloride binding to the surface of growing AgNFls results in nanoparticle enlargement predominantly at the points of their highest energy. These growth points are located at the tips of prismatic polygons in precursor prismatic morphologies that have been produced from thiolate-protected silver clusters whose coalescence is triggered with a strong base. For the practical aspects of AgNFl synthesis, concentrations of thiol and a strong base were found to be the key variables reliably controlling the extent of AgNFl faceting, as well as the kinetics of AgNFl formation and their stability. The selective growth of AgNFls progresses slower compared to that of non-faceted prisms: fewer nuclei can form leading to larger AgNFls with the diameter ranging from 130 to 2250 nm and asperity sizes on the order of 20 to 100 nm. Self-assembly of AgNFls yields columnar stacking. AgNFls were demonstrated to function as a promising substrate for surface-enhanced Raman scattering. SERS measurements were performed for a series of AgNFls with variable faceting, where the enhancement factors of 4.6 × 10(8) and 425 have been achieved for dry solid films and aqueous dispersions of non-aggregated AgNFls with single-particle enhancement, respectively. These SERS results are promising, especially in combination with that AgNFl nanoscale asperities can be conveniently tailored synthetically. Overall, AgNFls offer valuable opportunities for a system with synthetically variable nanoscale asperities.

Hydrogen peroxide and glucose concentration measurement using optical fiber grating sensors with corrodible plasmonic nanocoatings

PubMed Central

Zhang, Xuejun; Wu, Ze; Liu, Fu; Fu, Qiangqiang; Chen, Xiaoyong; Xu, Jian; Zhang, Zhaochuan; Huang, Yunyun; Tang, Yong; Guo, Tuan; Albert, Jacques

2018-01-01

We propose and demonstrate hydrogen peroxide (H2O2) and glucose concentration measurements using a plasmonic optical fiber sensor. The sensor utilizes a tilted fiber Bragg grating (TFBG) written in standard single mode communication fiber. The fiber is over coated with an nm-scale film of silver that supports surface plasmon resonances (SPRs). Such a tilted grating SPR structure provides a high density of narrow spectral resonances (Q-factor about 105) that overlap with the broader absorption band of the surface plasmon waves in the silver film, thereby providing an accurate tool to measure small shifts of the plasmon resonance frequencies. The H2O2 to be detected acts as an oxidant to etch the silver film, which has the effect of gradually decreasing the SPR attenuation. The etching rate of the silver film shows a clear relationship with the H2O2 concentration so that monitoring the progressively increasing attenuation of a selected surface plasmon resonance over a few minutes enables us to measure the H2O2 concentration with a limit of detection of 0.2 μM. Furthermore, the proposed method can be applied to the determination of glucose in human serum for a concentration range from 0 to 12 mM (within the physiological range of 3-8 mM) by monitoring the H2O2 produced by an enzymatic oxidation process. The sensor does not require accurate temperature control because of the inherent temperature insensitivity of TFBG devices referenced to the core mode resonance. A gold mirror coated on the fiber allows the sensor to work in reflection, which will facilitate the integration of the sensor with a hypodermic needle for in vitro measurements. The present study shows that Ag-coated TFBG-SPR can be applied as a promising type of sensing probe for optical detection of H2O2 and glucose detection in human serum. PMID:29675315

Hydrogen peroxide and glucose concentration measurement using optical fiber grating sensors with corrodible plasmonic nanocoatings.

PubMed

Zhang, Xuejun; Wu, Ze; Liu, Fu; Fu, Qiangqiang; Chen, Xiaoyong; Xu, Jian; Zhang, Zhaochuan; Huang, Yunyun; Tang, Yong; Guo, Tuan; Albert, Jacques

2018-04-01

We propose and demonstrate hydrogen peroxide (H 2 O 2 ) and glucose concentration measurements using a plasmonic optical fiber sensor. The sensor utilizes a tilted fiber Bragg grating (TFBG) written in standard single mode communication fiber. The fiber is over coated with an nm-scale film of silver that supports surface plasmon resonances (SPRs). Such a tilted grating SPR structure provides a high density of narrow spectral resonances (Q-factor about 10 5 ) that overlap with the broader absorption band of the surface plasmon waves in the silver film, thereby providing an accurate tool to measure small shifts of the plasmon resonance frequencies. The H 2 O 2 to be detected acts as an oxidant to etch the silver film, which has the effect of gradually decreasing the SPR attenuation. The etching rate of the silver film shows a clear relationship with the H 2 O 2 concentration so that monitoring the progressively increasing attenuation of a selected surface plasmon resonance over a few minutes enables us to measure the H 2 O 2 concentration with a limit of detection of 0.2 μM. Furthermore, the proposed method can be applied to the determination of glucose in human serum for a concentration range from 0 to 12 mM (within the physiological range of 3-8 mM) by monitoring the H 2 O 2 produced by an enzymatic oxidation process. The sensor does not require accurate temperature control because of the inherent temperature insensitivity of TFBG devices referenced to the core mode resonance. A gold mirror coated on the fiber allows the sensor to work in reflection, which will facilitate the integration of the sensor with a hypodermic needle for in vitro measurements. The present study shows that Ag-coated TFBG-SPR can be applied as a promising type of sensing probe for optical detection of H 2 O 2 and glucose detection in human serum.

Quantification of metal loading to Silver Creek through the Silver Maple Claims area, Park City, Utah, May 2002

USGS Publications Warehouse

Kimball, Briant A.; Johnson, Kevin K.; Runkel, Robert L.; Steiger, Judy I.

2004-01-01

The Silver Maple Claims area along Silver Creek, near Park City, Utah, is administered by the Bureau of Land Management. To quantify possible sources of elevated zinc concentrations in Silver Creek that exceed water-quality standards, the U.S. Geological Survey conducted a mass-loading study in May 2002 along a 1,400-meter reach of Silver Creek that included the Silver Maple Claims area. Additional samples were collected upstream and downstream from the injection reach to investigate other possible sources of zinc and other metals to the stream. Many metals were investigated in the study, but zinc is of particular concern for water-quality standards. The total loading of zinc along the study reach from Park City to Wanship, Utah, was about 49 kilograms per day. The Silver Maple Claims area contributed about 38 percent of this load. The Silver Creek tailings discharge pipe, which empties just inside the Silver Maple Claims area, contributed more than half the load of the Silver Maple Claims area. Substantial zinc loads also were added to Silver Creek downstream from the Silver Maple Claims area. Ground-water discharge upstream from the waste-water treatment plant contributed 20 percent of the total zinc load, and another 17 percent was contributed near the waste-water treatment plant. By identifying the specific areas where zinc and other metal loads are contributed to Silver Creek, it is possible to assess the needs of a remediation plan. For example, removing the tailings from the Silver Maple Claims area could contribute to lowering the zinc concentration in Silver Creek, but without also addressing the loading from the Silver Creek tailings discharge pipe and the ground-water discharge farther downstream, the zinc concentration could not be lowered enough to meet water-quality standards. Additional existing sources of zinc loading downstream from the Silver Maple Claims area could complicate the process of lowering zinc concentration to meet water-quality standards.

Plasmonic characterization of photo-induced silver nanoparticles extracted from silver halide based TEM film

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

Sudheer,, E-mail: sudheer@rrcat.gov.in; Tiwari, P.; Rai, V. N.

The plasmonic responses of silver nanoparticles extracted from silver halide based electron microscope film are investigated. Photo-reduction process is carried out to convert the silver halide grains into the metallic silver. The centrifuge technique is used for separating the silver nanoparticles from the residual solution. Morphological study performed by field emission scanning electron microscope (FESEM) shows that all the nanoparticles have an average diameter of ~120 nm with a high degree of mono dispersion in size. The localized surface plasmon resonance (LSPR) absorption peak at ~537 nm confirms the presence of large size silver nanoparticles.

Silver ion-mediated killing of a food pathogen: Melting curve analysis data of silver resistance genes and growth curve data.

PubMed

Gokulan, Kuppan; Williams, Katherine; Khare, Sangeeta

2017-04-01

Limited antibacterial activity of silver ions leached from silver-impregnated food contact materials could be due to: 1) the presence of silver resistance genes in tested bacteria ; or 2) lack of susceptibility to silver ion-mediated killing in the bacterial strain (K. Williams, L. Valencia, K. Gokulan, R. Trbojevich, S. Khare, 2016 [1]). This study contains data to address the specificity of silver resistance genes in Salmonella Typhimurium during the real time PCR using melting curve analysis and an assessment of the minimum inhibitory concentration of silver ions for Salmonella .

Plasmonic particles of colloidal silver in high-resolution recording media

NASA Astrophysics Data System (ADS)

Andreeva, O. V.; Andreeva, N. V.; Kuzmina, T. B.

2017-01-01

The optical properties of colloidal silver particles formed photographically in high-resolution silver halide photographic materials have been considered. The conditions that allow one to obtain exposed and developed light-sensitive silver halide particles in the form of colloidal particles of metallic silver having the properties of localized plasmons have been described. The results of the studies of the developed silver particles in traditional photographic materials for image holography and in nanoporous silver halide photographic materials for volume holography have been presented. The perspectives of using plasmonic silver nanoparticles produced photographically have been discussed.

Long-Range Trends in the Development of Higher Education in Mining

ERIC Educational Resources Information Center

Pzhevskii, V. V.

1978-01-01

Reviews the relationship between scientific and technological progress, needs of the Soviet economy, and capacities of higher education institutions in terms of the future of the mining industry. Mining specialists will have to prepare for technical progress in the extracting industries, growth in production, complex mechanization, and automation…

Progress Monitoring in Middle School Mathematics: Options and Issues

ERIC Educational Resources Information Center

Foegen, Anne

2008-01-01

This study investigated the technical features of six potential progress-monitoring measures in mathematics appropriate for use at the middle school level, including two commercially available measures for sixth-grade mathematics, two measures used in previous middle school studies, and two new measures of numeracy concepts. Five hundred…

10 CFR 600.341 - Monitoring and reporting program and financial performance.

Code of Federal Regulations, 2012 CFR

2012-01-01

... will be taken to address the deviations. (2) A final technical report if the award is for research and... dates for reports. At a minimum, requirements must include: (1) Periodic progress reports (at least... follows: (i) The program portions of the reports must address progress toward achieving program...

10 CFR 600.341 - Monitoring and reporting program and financial performance.

Code of Federal Regulations, 2014 CFR

2014-01-01

... will be taken to address the deviations. (2) A final technical report if the award is for research and... dates for reports. At a minimum, requirements must include: (1) Periodic progress reports (at least... follows: (i) The program portions of the reports must address progress toward achieving program...

10 CFR 600.341 - Monitoring and reporting program and financial performance.

Code of Federal Regulations, 2013 CFR

2013-01-01

... will be taken to address the deviations. (2) A final technical report if the award is for research and... dates for reports. At a minimum, requirements must include: (1) Periodic progress reports (at least... follows: (i) The program portions of the reports must address progress toward achieving program...

10 CFR 600.341 - Monitoring and reporting program and financial performance.

Code of Federal Regulations, 2011 CFR

2011-01-01

... will be taken to address the deviations. (2) A final technical report if the award is for research and... dates for reports. At a minimum, requirements must include: (1) Periodic progress reports (at least... follows: (i) The program portions of the reports must address progress toward achieving program...

Nuclear waste management. Semiannual progress report, October 1982-March 1983

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

Chikalla, T.D.; Powell, J.A.

1983-06-01

This document is one of a series of technical progress reports designed to report radioactive waste management programs at the Pacific Northwest Laboratory. Accomplishments in the following programs are reported: waste stabilization; Materials Characterization Center; waste isolation; low-level waste management; remedial action; and supporting studies.

Advancing Stage 2 Research on Measures for Monitoring Kindergarten Reading Progress

ERIC Educational Resources Information Center

Clemens, Nathan H.; Soohoo, Michelle M.; Wiley, Colby P.; Hsiao, Yu-Yu; Estrella, Ivonne; Allee-Smith, Paula J.; Yoon, Myeongsun

2018-01-01

Although several measures exist for frequently monitoring early reading progress, little research has specifically investigated their technical properties when administered on a frequent basis with kindergarten students. In this study, kindergarten students (N = 137) of whom the majority was receiving supplemental intervention for reading skills…

Rapid deposition of triangular silver nanoplates on planar surfaces: application to metal-enhanced fluorescence.

PubMed

Aslan, Kadir; Lakowicz, Joseph R; Geddes, Chris D

2005-04-07

A simple and rapid wet-chemical technique for the deposition of silver triangles on conventional glass substrates, which alleviates the need for lithography, has been developed. The technique is based on the seed-mediated cetyltrimethylammonium-bromide-directed growth of silver triangles on glass surfaces, where smaller spherical silver seeds that were attached to the surface were subsequently converted and grown into silver triangles in the presence of a cationic surfactant and silver ions. The size of the silver triangles was controlled by sequential immersion of silver seed-coated glass substrates into a growth solution and by the duration time of immersion. Atomic force microscopy studies revealed that the size of the silver triangles ranged between 100 and 500 nm. Interestingly, these new surfaces are a significant improvement over traditional silver island films for applications in metal-enhanced fluorescence. A routine 16-fold enhancement in emission intensity was typically observed, for protein-immobilized indocyanine green, with a relatively very low loading density of silver triangles on the glass surface.

High purity silver microcrystals recovered from silver wastes by eco-friendly process using hydrogen peroxide.

PubMed

Gatemala, Harnchana; Ekgasit, Sanong; Wongravee, Kanet

2017-07-01

A simple, rapid, and environmentally friendly process using hydrogen peroxide, was developed for recovering high purity silver directly from industry and laboratory wastes. Silver ammine complex, [Ag(NH 3 ) 2 ] + Cl - , derived from AgCl were generated and then directly reduced using H 2 O 2 to reliably turn into high purity microcrystalline silver (99.99%) examined by EDS and XRD. Morphology of the recovered silver microcrystals could be selectively tuned by an addition of poly(vinyl pyrrolidone). The main parameters in the recovering process including pH, concentration of Ag + and the mole ratio of H 2 O 2 :Ag + were carefully optimized though the central composite design (CCD). The optimized condition was employed for a trial recovery of 50 L silver ammine complex prepared from a collection of silver-wastes during 3-year research on industrial nanoparticle production. The recovered silver microcrystals >700 g could be recovered with 91.27%. The remaining solution after filtering of the recovered silver microcrystals can be used repeatedly (at least 8 cycles) without losing recovery efficiency. Matrix interferences including Pb 2+ and Cl - play a minimal role in our silver recovery process. Furthermore, the direct usage of the recovered silver microcrystals was demonstrated by using as a raw material of silver clay for creating a set of wearable silver jewelries. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mechanical, electrical, and thermal expansion properties of carbon nanotube-based silver and silver-palladium alloy composites

NASA Astrophysics Data System (ADS)

Pal, Hemant; Sharma, Vimal

2014-11-01

The mechanical, electrical, and thermal expansion properties of carbon nanotube (CNT)-based silver and silver-palladium (10:1, w/w) alloy nanocomposites are reported. To tailor the properties of silver, CNTs were incorporated into a silver matrix by a modified molecular level-mixing process. CNTs interact weakly with silver because of their non-reactive nature and lack of mutual solubility. Therefore, palladium was utilized as an alloying element to improve interfacial adhesion. Comparative microstructural characterizations and property evaluations of the nanocomposites were performed. The structural characterizations revealed that decorated type-CNTs were dispersed, embedded, and anchored into the silver matrix. The experimental results indicated that the modification of the silver and silver-palladium nanocomposite with CNT resulted in increases in the hardness and Young's modulus along with concomitant decreases in the electrical conductivity and the coefficient of thermal expansion (CTE). The hardness and Young's modulus of the nanocomposites were increased by 30%-40% whereas the CTE was decreased to 50%-60% of the CTE of silver. The significantly improved CTE and the mechanical properties of the CNT-reinforced silver and silver-palladium nanocomposites are correlated with the intriguing properties of CNTs and with good interfacial adhesion between the CNTs and silver as a result of the fabrication process and the contact action of palladium as an alloying element.

Synthesis and structural studies of praseodymium doped silver borate glasses

NASA Astrophysics Data System (ADS)

Jagadeesha Gowda, G. V.; Eraiah, B.

2013-02-01

Praseodymium doped silver borate glasses with nominal composition xPr6O11-(25-x)Ag2O-75B2O3 (x=0, 1, 2, 3, 4, 5) were prepared by melt quench technique. XRD pattern shows that there is no sharp peak it confirms the amorphous nature of the present glasses. The glass transition temperature (Tg) of this glass system have been studied using the Matac MBS-8000 Digital Signal Processing and Conventional Thermal Analysis (DTA) method. The Tg of these glasses increases with increase in concentration of Pr6O11 except at 0.2 mol%, Tg value is lower. 11B MAS-NMR shows the presence of sharp peak around 0.306 ppm. Chemical shift of these glasses decreases with mol% of rare earth oxide. FTIR spectra recorded in the region of 400 to 4000 cm-1. This studies revealed that the progressive addition Ag2O and Pr6O11 leads to modification of B2O3 into BO4 groups. Raman measurements of these glasses support the proposed interpretations of the experimental results.

Life testing of secondary silver-zinc cells

NASA Technical Reports Server (NTRS)

Brewer, Jeffrey C.; Doreswamy, Rajiv

1991-01-01

Testing on a variety of secondary silver-zinc (Ag-Zn) cells has been in progress at the Marshall Space Flight Center (MSFC) for over six years. The latest test involves a 350-Ah cell design that has been cycled at 10 C for 16 months. This design has achieved over 7200 low-earth-orbit (LEO) cycles as well as 17 deep discharges at an 85 percent depth of discharge. This test not only is a life test on these cells but also addresses different methods of storing these cells between the deep discharges. As the test is approaching completion, some interesting results are being seen. In particular, two of the four packs currently on test have failed to meet the 35-h (295-Ah) deep discharge requirement that was arbitrarily set at the beginning of the test. This capacity loss failure is likely a result of the storage method used on these two packs between deep discharges. The two packs are LEO cycled in such a way as to minimize overcharge in an attempt to prolong life.

21 CFR 310.548 - Drug products containing colloidal silver ingredients or silver salts offered over-the-counter...

Code of Federal Regulations, 2011 CFR

2011-04-01

... ingredients or silver salts offered over-the-counter (OTC) for the treatment and/or prevention of disease. 310...) for the treatment and/or prevention of disease. (a) Colloidal silver ingredients and silver salts have... disease conditions. There are serious and complicating aspects to many of the diseases these silver...

21 CFR 310.548 - Drug products containing colloidal silver ingredients or silver salts offered over-the-counter...

Code of Federal Regulations, 2010 CFR

2010-04-01

... ingredients or silver salts offered over-the-counter (OTC) for the treatment and/or prevention of disease. 310...) for the treatment and/or prevention of disease. (a) Colloidal silver ingredients and silver salts have... disease conditions. There are serious and complicating aspects to many of the diseases these silver...

21 CFR 310.548 - Drug products containing colloidal silver ingredients or silver salts offered over-the-counter...

Code of Federal Regulations, 2013 CFR

2013-04-01

... ingredients or silver salts offered over-the-counter (OTC) for the treatment and/or prevention of disease. 310...) for the treatment and/or prevention of disease. (a) Colloidal silver ingredients and silver salts have... disease conditions. There are serious and complicating aspects to many of the diseases these silver...

21 CFR 310.548 - Drug products containing colloidal silver ingredients or silver salts offered over-the-counter...

Code of Federal Regulations, 2012 CFR

2012-04-01

... ingredients or silver salts offered over-the-counter (OTC) for the treatment and/or prevention of disease. 310...) for the treatment and/or prevention of disease. (a) Colloidal silver ingredients and silver salts have... disease conditions. There are serious and complicating aspects to many of the diseases these silver...

21 CFR 310.548 - Drug products containing colloidal silver ingredients or silver salts offered over-the-counter...

Code of Federal Regulations, 2014 CFR

2014-04-01

... ingredients or silver salts offered over-the-counter (OTC) for the treatment and/or prevention of disease. 310...) for the treatment and/or prevention of disease. (a) Colloidal silver ingredients and silver salts have... disease conditions. There are serious and complicating aspects to many of the diseases these silver...

77 FR 61661 - Price for the American Eagle Silver Proof and Uncirculated Coins and the America the Beautiful...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-10

... DEPARTMENT OF THE TREASURY United States Mint Price for the American Eagle Silver Proof and... price of silver, the United States Mint is raising the price of its American Eagle Silver Proof and... price 2012 American Eagle Silver Proof $59.95 2012 American Eagle Silver Uncirculated 50.95 2011...

Mechanism of Prophylaxis by Silver Compounds against Infection of Burns

PubMed Central

Ricketts, C. R.; Lowbury, E. J. L.; Lawrence, J. C.; Hall, M.; Wilkins, M. D.

1970-01-01

To clarify tthe mechanism by which local application of silver compounds protects burns against infection, an ion-specific electrode was used to measùre the concentration of silver ions in solutions. By this method it was shown that in burn dressings silver ions were reduced to a very low level by precipitation as silver chloride. The antibacterial effect was found to depend on the availability of silver ions from solution in contact with precipitate. Between 10-5 and 10-6 molar silver nitrate solution in water was rapidly bactericidal. The minimal amount of silver nitrate causing inhibition of respiration of skin in tissue culture was about 25 times the minimal concentration of silver nitrate that inhibited growth of Pseudomonas aeruginosa. PMID:4986877

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

NONE

This report summarizes geothermal technical assistance, R&D, and technology transfer activities of the Geo-Heat Center. It describes 95 contacts with parties during this period related to technical assistance with goethermal direct heat projects. Areas dealt with include geothermal heat pumps, space heating, greenhouses, aquaculture, equipment, economics, and resources. Research activities are summarized on geothermal district heating system cost evaluation and silica waste utilization project. Outreach activities include publication of a geothermal direct use Bulletin, dissemination of information, goethermal library, technical papers and seminars, and progress monitor reports on geothermal resources and utilization.

New Paradigm Shift for the Green Synthesis of Antibacterial Silver Nanoparticles Utilizing Plant Extracts

PubMed Central

2014-01-01

This review covers general information regarding the green synthesis of antibacterial silver nanoparticles. Owing to their antibacterial properties, silver nanoparticles are widely used in many areas, especially biomedical applications. In green synthesis practices, the chemical reducing agents are eliminated, and biological entities are utilized to convert silver ions to silver nanoparticles. Among the various biological entities, natural plant extracts have emerged as green reducing agents, providing eco-friendly routes for the preparation of silver nanomaterials. The most obvious merits of green synthesis are the increased biocompatibility of the resulting silver nanoparticles and the ease with which the reaction can be carried out. This review summarizes some of the plant extracts that are used to produce antibacterial silver nanoparticles. Additionally, background information regarding the green synthesis and antibacterial activity of silver nanoparticles is provided. Finally, the toxicological aspects of silver nanoparticles are briefly mentioned. PMID:25343010

Silver Recycling in the United States in 2000

USGS Publications Warehouse

Hilliard, Henry E.

2003-01-01

In 2000, the global silver supply deficit (the difference between mine and scrap supply and silver demand) was more than 3,000 metric tons. U.S. silver demand for photographic applications alone was nearly equal to annual U.S. silver production. Until 1968, the U.S. silver deficit was filled by withdrawals from the U.S. Treasury reserves. In 2000, the deficit was filled by destocking, imports, and recycling. Photographic wastes, spent catalysts, and electronic scrap are the major sources of materials for silver recycling. Nearly 1,800 tons of silver contained in these materials were available for recycling in 2000. Other recyclable silver-bearing materials include dental alloys, jewelry, and silverware. In 2000, an estimated 1,700 tons of silver were recovered from secondary sources in the United States. The U.S. recycling efficiency for old scrap was calculated to have been 97 percent in 2000; the recycling rate was estimated to be 32 percent.

Silver recycling in the United States in 2000

USGS Publications Warehouse

Hilliard, Henry E.

2003-01-01

In 2000, the global silver supply deficit (the difference between mine and scrap supply and silver demand) was more than 3,000 metric tons. U.S. silver demand for photographic applications alone was nearly equal to annual U.S. silver production. Until 1968, the U.S. silver deficit was filled by withdrawals from the U.S. Treasury reserves. In 2000, the deficit was filled by destocking, imports, and recycling. Photographic wastes, spent catalysts, and electronic scrap are the major sources of materials for silver recycling. Nearly 1,800 metric tons of silver contained in these materials were available for recycling in 2000. Other recyclable silver-bearing materials include dental alloys, jewelry, and silverware. In 2000, an estimated 1,700 tons of silver were recovered from secondary sources in the United States. The U.S. recycling efficiency for old scrap was calculated to have been 97 percent in 2000; the recycling rate was estimated to be 32 percent.

Applications of nanotechnology in food packaging and food safety: barrier materials, antimicrobials and sensors.

PubMed

Duncan, Timothy V

2011-11-01

In this article, several applications of nanomaterials in food packaging and food safety are reviewed, including: polymer/clay nanocomposites as high barrier packaging materials, silver nanoparticles as potent antimicrobial agents, and nanosensors and nanomaterial-based assays for the detection of food-relevant analytes (gasses, small organic molecules and food-borne pathogens). In addition to covering the technical aspects of these topics, the current commercial status and understanding of health implications of these technologies are also discussed. These applications were chosen because they do not involve direct addition of nanoparticles to consumed foods, and thus are more likely to be marketed to the public in the short term. Published by Elsevier Inc.

The evolution of endovascular electroencephalography: historical perspective and future applications.

PubMed

Sefcik, Roberta K; Opie, Nicholas L; John, Sam E; Kellner, Christopher P; Mocco, J; Oxley, Thomas J

2016-05-01

Current standard practice requires an invasive approach to the recording of electroencephalography (EEG) for epilepsy surgery, deep brain stimulation (DBS), and brain-machine interfaces (BMIs). The development of endovascular techniques offers a minimally invasive route to recording EEG from deep brain structures. This historical perspective aims to describe the technical progress in endovascular EEG by reviewing the first endovascular recordings made using a wire electrode, which was followed by the development of nanowire and catheter recordings and, finally, the most recent progress in stent-electrode recordings. The technical progress in device technology over time and the development of the ability to record chronic intravenous EEG from electrode arrays is described. Future applications for the use of endovascular EEG in the preoperative and operative management of epilepsy surgery are then discussed, followed by the possibility of the technique's future application in minimally invasive operative approaches to DBS and BMI.

Silver distribution and release from an antimicrobial denture base resin containing silver colloidal nanoparticles.

PubMed

Monteiro, Douglas Roberto; Gorup, Luiz Fernando; Takamiya, Aline Satie; de Camargo, Emerson Rodrigues; Filho, Adhemar Colla Ruvolo; Barbosa, Debora Barros

2012-01-01

The aim of this study was to evaluate a denture base resin containing silver colloidal nanoparticles through morphological analysis to check the distribution and dispersion of these particles in the polymer and by testing the silver release in deionized water at different time periods. A Lucitone 550 denture resin was used, and silver nanoparticles were synthesized by reduction of silver nitrate with sodium citrate. The acrylic resin was prepared in accordance with the manufacturers' instructions, and silver nanoparticle suspension was added to the acrylic resin monomer in different concentrations (0.05, 0.5, and 5 vol% silver colloidal). Controls devoid of silver nanoparticles were included. The specimens were stored in deionized water at 37°C for 7, 15, 30, 60, and 120 days, and each solution was analyzed using atomic absorption spectroscopy. Silver was not detected in deionized water regardless of the silver nanoparticles added to the resin and of the storage period. Micrographs showed that with lower concentrations, the distribution of silver nanoparticles was reduced, whereas their dispersion was improved in the polymer. Moreover, after 120 days of storage, nanoparticles were mainly located on the surface of the nanocomposite specimens. Incorporation of silver nanoparticles in the acrylic resin was evidenced. Moreover, silver was not detected by the detection limit of the atomic absorption spectrophotometer used in this study, even after 120 days of storage in deionized water. Silver nanoparticles are incorporated in the PMMA denture resin to attain an effective antimicrobial material to help control common infections involving oral mucosal tissues in complete denture wearers. © 2011 by the American College of Prosthodontists.

Unprecedented Silver Resistance in Clinically Isolated Enterobacteriaceae: Major Implications for Burn and Wound Management

PubMed Central

Norton, Rhy; Austin, Cindy; Mitchell, Amber; Zank, Sara; Durham, Paul

2015-01-01

Increased utilization of inorganic silver as an adjunctive to many medical devices has raised concerns of emergent silver resistance in clinical bacteria. Although the molecular basis for silver resistance has been previously characterized, to date, significant phenotypic expression of these genes in clinical settings is yet to be observed. Here, we identified the first strains of clinical bacteria expressing silver resistance at a level that could significantly impact wound care and the use of silver-based dressings. Screening of 859 clinical isolates confirmed 31 harbored at least 1 silver resistance gene. Despite the presence of these genes, MIC testing revealed most of the bacteria displayed little or no increase in resistance to ionic silver (200 to 300 μM Ag+). However, 2 isolates (Klebsiella pneumonia and Enterobacter cloacae) were capable of robust growth at exceedingly high silver concentrations, with MIC values reaching 5,500 μM Ag+. DNA sequencing of these two strains revealed the presence of genes homologous to known genetic determinants of heavy metal resistance. Darkening of the bacteria's pigment was observed after exposure to high silver concentrations. Scanning electron microscopy images showed the presence of silver nanoparticles embedded in the extracellular polymeric substance of both isolates. This finding suggested that the isolates may neutralize ionic silver via reduction to elemental silver. Antimicrobial testing revealed both organisms to be completely resistant to many commercially available silver-impregnated burn and wound dressings. Taken together, these findings provide the first evidence of clinical bacteria capable of expressing silver resistance at levels that could significantly impact wound management. PMID:26014954

Similarities and Differences between Silver Ions and Silver in Nanoforms as Antibacterial Agents

PubMed Central

Kędziora, Anna; Speruda, Mateusz; Rybka, Jacek; Łukowiak, Anna; Bugla-Płoskońska, Gabriela

2018-01-01

Silver is considered as antibacterial agent with well-known mode of action and bacterial resistance against it is well described. The development of nanotechnology provided different methods for the modification of the chemical and physical structure of silver, which may increase its antibacterial potential. The physico-chemical properties of silver nanoparticles and their interaction with living cells differs substantially from those of silver ions. Moreover, the variety of the forms and characteristics of various silver nanoparticles are also responsible for differences in their antibacterial mode of action and probably bacterial mechanism of resistance. The paper discusses in details the aforementioned aspects of silver activity. PMID:29393866

The dual role of silver during silicon etching in HF solution.

PubMed

Abouda-Lachiheb, Manel; Nafie, Nesma; Bouaicha, Mongi

2012-08-13

It was reported that during silicon etching, silver was subjected to have a controversial role. Some researchers debate that silver protects silicon, and, at the same time, other ones confirm that silver catalyzes silicon underneath. In this paper, we give experimental results arguing the dual role that silver has during the formation of silicon nanostructures. We give a proof that the role of silver depends on the experimental details and the intrinsic properties of silver during its deposition on the silicon wafer. Through our investigations, we tracked the silver particles that indicated which mechanism is involved. Characterizations of the prepared samples were made using a scanning electron microscope.

Colored and semitransparent silver nanoparticle layers deposited by spin coating of silver nanoink

NASA Astrophysics Data System (ADS)

Yoon, Hoi Jin; Jo, Yejin; Jeong, Sunho; Lim, Jung Wook; Lee, Seung-Yun

2018-05-01

In this letter, we report on the fabrication and characterization of colored and semitransparent silver nanoparticle layers. A spin coating of silver nanoink is used to deposit silver nanoparticle layers onto substrates. The transmittance and color of the silver nanoparticle layers are significantly dependent on the spin speed and nanoink concentration, owing to variations in the size and distribution of the nanoparticles. Both color variation and efficiency improvement are achieved with the application of silver nanoparticles to semitransparent Si thin-film solar cells, which is associated with the excitation of the dipole or quadruple plasmon modes of the silver nanoparticles.

THE DEVELOPMENT OF ACHIEVEMENT MEASURES FOR TRADE AND TECHNICAL EDUCATION. PROGRESS REPORT NUMBER THREE.

ERIC Educational Resources Information Center

BALDWIN, THOMAS S.

DURING THIS PERIOD FROM SEPTEMBER 1 THROUGH NOVEMBER 30, 1966, 35 FIELD CONSULTANTS COMPLETED ANALYSIS OF THEIR INDIVIDUAL TRADE AND TECHNICAL CURRICULUMS. THESE ANALYSES WERE DEVELOPED INTO AN OUTLINE TO SERVE AS A GUIDE FOR DEVELOPING ACHIEVEMENT TESTS. THE FINAL OUTLINE WAS DIVIDED INTO AS MANY DIFFERENT AREAS AS THE CONSULTANTS FELT NECESSARY…

25 CFR 547.7 - What are the minimum technical hardware standards applicable to Class II gaming systems?

Code of Federal Regulations, 2011 CFR

2011-04-01

... OF CLASS II GAMES § 547.7 What are the minimum technical hardware standards applicable to Class II... the game, and are specially manufactured or proprietary and not off-the-shelf, shall display a unique... outcome or integrity of any game, progressive award, financial instrument, cashless transaction, voucher...

25 CFR 547.7 - What are the minimum technical hardware standards applicable to Class II gaming systems?

Code of Federal Regulations, 2012 CFR

2012-04-01

... OF CLASS II GAMES § 547.7 What are the minimum technical hardware standards applicable to Class II... the game, and are specially manufactured or proprietary and not off-the-shelf, shall display a unique... outcome or integrity of any game, progressive award, financial instrument, cashless transaction, voucher...

25 CFR 547.7 - What are the minimum technical hardware standards applicable to Class II gaming systems?

Code of Federal Regulations, 2010 CFR

2010-04-01

... OF CLASS II GAMES § 547.7 What are the minimum technical hardware standards applicable to Class II... the game, and are specially manufactured or proprietary and not off-the-shelf, shall display a unique... outcome or integrity of any game, progressive award, financial instrument, cashless transaction, voucher...

Diagnostic Efficiency of easyCBM[R] Math: Washington State. Technical Report #1008

ERIC Educational Resources Information Center

Anderson, Daniel; Alonzo, Julie; Tindal, Gerald

2010-01-01

easyCBM[R] is an online benchmark and progress monitoring assessment system designed for use within a response to intervention framework. Educators using easyCBM[R] are often interested in using the results to predict students' state test performance. In the following technical document, we report diagnostic efficiency statistics using a sample…

U.S. TIMSS and PIRLS 2011 Technical Report and User's Guide. NCES 2013-046

ERIC Educational Resources Information Center

Kastberg, David; Roey, Stephen; Ferraro, David; Lemanski, Nita; Erberber, Ebru

2013-01-01

The "U.S. TIMSS and PIRLS 2011 Technical Report and User's Guide" provides an overview of the design and implementation of the Trends in International Mathematics and Science Study (TIMSS) 2011 and the Progress in International Reading Literacy Study (PIRLS) 2011 in the United States and the nine participating benchmarking states:…

Longitudinal Surveys of Australian Youth (LSAY) 1998 Cohort: Wave 12 (2009)--Questionnaire. Technical Report 58A

ERIC Educational Resources Information Center

National Centre for Vocational Education Research (NCVER), 2010

2010-01-01

The Longitudinal Surveys of Australian Youth (LSAY) program studies the progress of several groups of young Australians as they move from school into post-secondary education and work. This technical paper contains the questionnaire for the LSAY 1998 cohort Wave 12 (2009) data set. [For the accompanying frequency tables, "Longitudinal Surveys…

The Development of the easyCBM CCSS Reading Assessments: Grade 3. Technical Report #1221

ERIC Educational Resources Information Center

Alonzo, Julie; Park, Bitnara Jasmine; Tindal, Gerald

2012-01-01

In this technical report, we document the development and piloting of easyCBM reading measures aligned to the Common Core State Standards, designed for use in screening students at risk for reading difficulty and monitoring their progress as they develop reading skills. The measures, which assess students' ability to respond to…

Developing Technical Writing Skills in the Physical Chemistry Laboratory: A Progressive Approach Employing Peer Review

ERIC Educational Resources Information Center

Gragson, Derek E.; Hagen, John P.

2010-01-01

Writing formal "journal-style" lab reports is often one of the requirements chemistry and biochemistry students encounter in the physical chemistry laboratory. Helping students improve their technical writing skills is the primary reason this type of writing is a requirement in the physical chemistry laboratory. Developing these skills is an…

Quality and Quality Assurance in Technical and Vocational Education and Training. Thematic Studies

ERIC Educational Resources Information Center

Seyfried, Erwin

2008-01-01

In many countries in both the Mediterranean region and the European Union (EU), interest in the quality of, and improvements to, technical and vocational education and training (TVET) systems has increased progressively in recent years. The main reason underlying this interest is a growing awareness of the key role played by education and training…

The Development of CBM Vocabulary Measures: Grade 4. Technical Report #1211

ERIC Educational Resources Information Center

Alonzo, Julie; Anderson, Daniel; Park, Bitnara Jasmine; Tindal, Gerald

2012-01-01

In this technical report, we describe the development and piloting of a series of vocabulary assessments intended for use with students in grades two through eight. These measures, available as part of easyCBM[TM], an online progress monitoring and benchmark/screening assessment system, were developed in 2010 and administered to approximately 1200…

The Development of CBM Vocabulary Measures: Grade 7. Technical Report #1214

ERIC Educational Resources Information Center

Alonzo, Julie; Anderson, Daniel; Park, Bitnara Jasmine; Tindal, Gerald

2012-01-01

In this technical report, we describe the development and piloting of a series of vocabulary assessments intended for use with students in grades two through eight. These measures, available as part of easyCBM[TM], an online progress monitoring and benchmark/screening assessment system, were developed in 2010 and administered to approximately 1200…

The Development of CBM Vocabulary Measures: Grade 5. Technical Report #1212

ERIC Educational Resources Information Center

Alonzo, Julie; Anderson, Daniel; Park, Bitnara Jasmine; Tindal, Gerald

2012-01-01

In this technical report, we describe the development and piloting of a series of vocabulary assessments intended for use with students in grades two through eight. These measures, available as part of easyCBM[TM], an online progress monitoring and benchmark/screening assessment system, were developed in 2010 and administered to approximately 1200…

The Development of CBM Vocabulary Measures: Grade 8. Technical Report #1215

ERIC Educational Resources Information Center

Alonzo, Julie; Anderson, Daniel; Park, Bitnara Jasmine; Tindal, Gerald

2012-01-01

In this technical report, we describe the development and piloting of a series of vocabulary assessments intended for use with students in grades two through eight. These measures, available as part of easyCBM[TM], an online progress monitoring and benchmark/screening assessment system, were developed in 2010 and administered to approximately 1200…

The Development of CBM Vocabulary Measures: Grade 2. Technical Report #1209

ERIC Educational Resources Information Center

Alonzo, Julie; Anderson, Daniel; Park, Bitnara Jasmine; Tindal, Gerald

2012-01-01

In this technical report, we describe the development and piloting of a series of vocabulary assessments intended for use with students in grades two through eight. These measures, available as part of easyCBM[TM], an online progress monitoring and benchmark/screening assessment system, were developed in 2010 and administered to approximately 1200…

The Development of CBM Vocabulary Measures: Grade 3. Technical Report #1210

ERIC Educational Resources Information Center

Alonzo, Julie; Anderson, Daniel; Park, Bitnara Jasmine; Tindal, Gerald

2012-01-01

In this technical report, we describe the development and piloting of a series of vocabulary assessments intended for use with students in grades two through eight. These measures, available as part of easyCBM[TM], an online progress monitoring and benchmark/screening assessment system, were developed in 2010 and administered to approximately 1200…

The Development of CBM Vocabulary Measures: Grade 6. Technical Report # 1213

ERIC Educational Resources Information Center

Alonzo, Julie; Anderson, Daniel; Park, Bitnara Jasmine; Tindal, Gerald

2012-01-01

In this technical report, we describe the development and piloting of a series of vocabulary assessments intended for use with students in grades two through eight. These measures, available as part of easyCBM[TM], an online progress monitoring and benchmark/screening assessment system, were developed in 2010 and administered to approximately 1200…

Application of Communications Satellites to Educational Development. Final Technical Report, September 1, 1969-August 31, 1975.

ERIC Educational Resources Information Center

Morgan, Robert P.

Research is summarized in a brief final report built around a four-section bibliography. The first section lists periodic progress reports and articles which provide an overview of the program, including articles which pertain primarily to educational rather than technical aspects of satellite utilization. Theses carried out in the fields of…

Technical efficiency and productivity of Chinese county hospitals: an exploratory study in Henan province, China.

PubMed

Cheng, Zhaohui; Tao, Hongbing; Cai, Miao; Lin, Haifeng; Lin, Xiaojun; Shu, Qin; Zhang, Ru-Ning

2015-09-09

Chinese county hospitals have been excessively enlarging their scale during the healthcare reform since 2009. The purpose of this paper is to examine the technical efficiency and productivity of county hospitals during the reform process, and to determine whether, and how, efficiency is affected by various factors. 114 sample county hospitals were selected from Henan province, China, from 2010 to 2012. Data envelopment analysis was employed to estimate the technical and scale efficiency of sample hospitals. The Malmquist index was used to calculate productivity changes over time. Tobit regression was used to regress against 4 environmental factors and 5 institutional factors that affected the technical efficiency. (1) 112 (98.2%), 112 (98.2%) and 104 (91.2%) of the 114 sample hospitals ran inefficiently in 2010, 2011 and 2012, with average technical efficiency of 0.697, 0.748 and 0.790, respectively. (2) On average, during 2010-2012, productivity of sample county hospitals increased by 7.8%, which was produced by the progress in technical efficiency changes and technological changes of 0.9% and 6.8%, respectively. (3) Tobit regression analysis indicated that government subsidy, hospital size with above 618 beds and average length of stay assumed a negative sign with technical efficiency; bed occupancy rate, ratio of beds to nurses and ratio of nurses to physicians assumed a positive sign with technical efficiency. There was considerable space for technical efficiency improvement in Henan county hospitals. During 2010-2012, sample hospitals experienced productivity progress; however, the adverse change in pure technical efficiency should be emphasised. Moreover, according to the Tobit results, policy interventions that strictly supervise hospital bed scale, shorten the average length of stay and coordinate the proportion among physicians, nurses and beds, would benefit hospital efficiency. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Technical efficiency and productivity of Chinese county hospitals: an exploratory study in Henan province, China

PubMed Central

Cheng, Zhaohui; Tao, Hongbing; Cai, Miao; Lin, Haifeng; Lin, Xiaojun; Shu, Qin; Zhang, Ru-ning

2015-01-01

Objectives Chinese county hospitals have been excessively enlarging their scale during the healthcare reform since 2009. The purpose of this paper is to examine the technical efficiency and productivity of county hospitals during the reform process, and to determine whether, and how, efficiency is affected by various factors. Setting and participants 114 sample county hospitals were selected from Henan province, China, from 2010 to 2012. Outcome measures Data envelopment analysis was employed to estimate the technical and scale efficiency of sample hospitals. The Malmquist index was used to calculate productivity changes over time. Tobit regression was used to regress against 4 environmental factors and 5 institutional factors that affected the technical efficiency. Results (1) 112 (98.2%), 112 (98.2%) and 104 (91.2%) of the 114 sample hospitals ran inefficiently in 2010, 2011 and 2012, with average technical efficiency of 0.697, 0.748 and 0.790, respectively. (2) On average, during 2010–2012, productivity of sample county hospitals increased by 7.8%, which was produced by the progress in technical efficiency changes and technological changes of 0.9% and 6.8%, respectively. (3) Tobit regression analysis indicated that government subsidy, hospital size with above 618 beds and average length of stay assumed a negative sign with technical efficiency; bed occupancy rate, ratio of beds to nurses and ratio of nurses to physicians assumed a positive sign with technical efficiency. Conclusions There was considerable space for technical efficiency improvement in Henan county hospitals. During 2010–2012, sample hospitals experienced productivity progress; however, the adverse change in pure technical efficiency should be emphasised. Moreover, according to the Tobit results, policy interventions that strictly supervise hospital bed scale, shorten the average length of stay and coordinate the proportion among physicians, nurses and beds, would benefit hospital efficiency. PMID:26353864

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

Gauglitz, Phillip A.; Bontha, Jagannadha R.; Daniel, Richard C.

The Hanford Waste Treatment and Immobilization Plant (WTP) is currently being designed and constructed to pretreat and vitrify a large portion of the waste in the 177 underground waste storage tanks at the Hanford Site. A number of technical issues related to the design of the pretreatment facility (PTF) of the WTP have been identified. These issues must be resolved prior to the U.S. Department of Energy (DOE) Office of River Protection (ORP) reaching a decision to proceed with engineering, procurement, and construction activities for the PTF. One of the issues is Technical Issue T1 - Hydrogen Gas Release frommore » Vessels (hereafter referred to as T1). The focus of T1 is identifying controls for hydrogen release and completing any testing required to close the technical issue. In advance of selecting specific controls for hydrogen gas safety, a number of preliminary technical studies were initiated to support anticipated future testing and to improve the understanding of hydrogen gas generation, retention, and release within PTF vessels. These activities supported the development of a plan defining an overall strategy and approach for addressing T1 and achieving technical endpoints identified for T1. Preliminary studies also supported the development of a test plan for conducting testing and analysis to support closing T1. Both of these plans were developed in advance of selecting specific controls, and in the course of working on T1 it was decided that the testing and analysis identified in the test plan were not immediately needed. However, planning activities and preliminary studies led to significant technical progress in a number of areas. This report summarizes the progress to date from the preliminary technical studies. The technical results in this report should not be used for WTP design or safety and hazards analyses and technical results are marked with the following statement: “Preliminary Technical Results for Planning – Not to be used for WTP Design or Safety Analyses.”« less

In situ green synthesis and characterization of sericin-silver nanoparticle composite with effective antibacterial activity and good biocompatibility.

PubMed

He, Huawei; Tao, Gang; Wang, Yejing; Cai, Rui; Guo, Pengchao; Chen, Liqun; Zuo, Hua; Zhao, Ping; Xia, Qingyou

2017-11-01

Silver nanoparticle has been widely applied to a variety of fields for its outstanding antimicrobial activity. However, the stability of silver nanoparticle limits its application under certain conditions. Thus, improving the stability of silver nanoparticle via biosynthesis is a promising shortcut to expand its application. Sericin from silkworm cocoon has good hydrophilicity, reaction activity, biocompatibility and biodegradability. In this study, we developed a novel, simple, one-step biosynthesis method to prepare sericin-silver nanoparticle composite in situ in solution. Sericin served as the reductant of silver ion, the dispersant and stabilizer of the prepared sericin-silver nanoparticle composite. Natural light was the only power source used to catalyze the synthesis of silver nanoparticle in situ in solution. The novel sericin-silver nanoparticle composite was characterized by ultraviolet-visible and fluorescence spectroscopy, X-ray diffraction, transmission electron microscopy and fourier transform infrared spectroscopy. The results showed silver nanoparticle could be synthesized through the reduction of AgNO 3 by the phenolic hydroxyl group of tyrosine residues of sericin under the catalysis of natural light. The synthesized silver nanoparticle had good crystalline, size distribution and long-term stability at room temperature. Light irradiation was essential for the preparation of sericin-silver nanoparticle composite. The antibacterial activity assay showed 25mg/L and 100mg/L were the minimum concentrations of sericin-silver nanoparticle composite required to inhibit the growth of Staphylococcus aureus and kill this bacterium, respectively. The cytotoxicity assay showed cell viability and cell growth were almost not affected by sericin-silver nanoparticle composite under the concentration of 25mg/L. Our study suggested the preparation of sericin-silver nanoparticle composite was environmentally friendly and energy conservation, and the prepared sericin-silver nanoparticle composite had long-term stability, effective antibacterial activity and good biocompatibility. This novel sericin-silver nanoparticle composite has shown great potentials for biomedical application such as antibacterial agent and wound care. Copyright © 2017 Elsevier B.V. All rights reserved.

Analyzing silver concentration in soil using laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Prasetyo, S.; Isnaeni; Zaitun; Mitchell, K.; Suliyanti, M. M.; Herbani, Y.

2018-03-01

Determination of concentration of heavy metal ions in soil, such as silver, is very important to study soil pollution levels. Several techniques have been developed to determine silver ion concentration in soil. In this paper, we utilized laser-induced breakdown spectroscopy (LIBS) to study silver concentration in soil. We used four different data analysis methods to calculate silver concentration. In this case, we prepared soil samples with different silver ion concentrations from 400 ppm to 1000 ppm. Our analysis was focused on the 843.15 nm silver atomic absorption line. We found that plasma intensity increased as silver concentration increased. Our findings were based on our analysis using four different analysis methods. We believe that these analysis methods are able to calculate silver concentration in soil using LIBS.

Characterization of engineered nanoparticles in commercially available spray disinfectant products advertised to contain colloidal silver.

PubMed

Rogers, Kim R; Navratilova, Jana; Stefaniak, Aleksandr; Bowers, Lauren; Knepp, Alycia K; Al-Abed, Souhail R; Potter, Phillip; Gitipour, Alireza; Radwan, Islam; Nelson, Clay; Bradham, Karen D

2018-04-01

Given the potential for human exposure to silver nanoparticles from spray disinfectants and dietary supplements, we characterized the silver-containing nanoparticles in 22 commercial products that advertised the use of silver or colloidal silver as the active ingredient. Characterization parameters included: total silver, fractionated silver (particulate and dissolved), primary particle size distribution, hydrodynamic diameter, particle number, and plasmon resonance absorbance. A high degree of variability between claimed and measured values for total silver was observed. Only 7 of the products showed total silver concentrations within 20% of their nominally reported values. In addition, significant variations in the relative percentages of particulate vs. soluble silver were also measured in many of these products reporting to be colloidal. Primary silver particle size distributions by transmission electron microscopy (TEM) showed two populations of particles - smaller particles (<5nm) and larger particles between 20 and 40nm. Hydrodynamic diameter measurements using nanoparticle tracking analysis (NTA) correlated well with TEM analysis for the larger particles. Z-average (Z-Avg) values measured using dynamic light scattering (DLS); however, were typically larger than both NTA or TEM particle diameters. Plasmon resonance absorbance signatures (peak absorbance at around 400nm indicative of metallic silver nanoparticles) were only noted in 4 of the 9 yellow-brown colored suspensions. Although the total silver concentrations were variable among products, ranging from 0.54mg/L to 960mg/L, silver containing nanoparticles were identified in all of the product suspensions by TEM. Published by Elsevier B.V.

Silver Flakes and Silver Dendrites for Hybrid Electrically Conductive Adhesives with Enhanced Conductivity

NASA Astrophysics Data System (ADS)

Ma, Hongru; Li, Zhuo; Tian, Xun; Yan, Shaocun; Li, Zhe; Guo, Xuhong; Ma, Yanqing; Ma, Lei

2018-03-01

Silver dendrites were prepared by a facile replacement reaction between silver nitrate and zinc microparticles of 20 μm in size. The influence of reactant molar ratio, reaction solution volume, silver nitrate concentration, and reaction time on the morphology of dendrites was investigated systematically. It was found that uniform tree-like silver structures are synthesized under the optimal conditions. Their structure can be described as a trunk, symmetrical branches, and leaves, which length scales of 5-10, 1-2 μm, and 100-300 nm, respectively. All features were systematically characterized by scanning electron microscopy, transmission electron microscopy (TEM), high-resolution TEM, and x-ray powder diffraction. A hybrid fillers system using silver flakes and dendrites as electrically conductive adhesives (ECAs) exhibited excellent overall performance. This good conductivity can be attributed mainly to the synergy between the silver microflakes (5-20 μm sized irregular sheet structures) and dendrites, allowing more conductive pathways to be formed between the fillers. In order to further optimize the overall electrical conductivity, various mixtures of silver microflakes and silver dendrites were tested in ECAs, with results indicating that the highest conductivity was shown when the amounts of silver microflakes, silver dendrites and the polymer matrix were 69.4 wt.% (20.82 vol.%), 0.6 wt.% (0.18 vol.%), and 30.0 wt.% (79.00 vol.%), respectively. The corresponding mass ratio of silver flakes to silver dendrites was 347:3. The resistivity of ECAs reached as low as 1.7 × 10-4 Ω cm.

Multilevel modeling of retention and disinfection efficacy of silver nanoparticles on ceramic water filters.

PubMed

Mikelonis, Anne M; Lawler, Desmond F; Passalacqua, Paola

2016-10-01

This research examined how variations in synthesis methods of silver nanoparticles affect both the release of silver from ceramic water filters (CWFs) and disinfection efficacy. The silver nanoparticles used were stabilized by four different molecules: citrate, polyvinylpyrrolidone, branched polyethylenimine, and casein. A multilevel statistical model was built to quantify if there was a significant difference in: a) extent of silver lost, b) initial amount of silver lost, c) silver lost for water of different quality, and d) total coliform removal. Experiments were performed on location at Pure Home Water, a CWF factory in Tamale, Ghana using stored rainwater and dugout water (a local surface water). The results indicated that using dugout vs. rainwater significantly affects the initial (p-value 0.0015) and sustained (p-value 0.0124) loss of silver, but that silver type does not have a significant effect. On average, dugout water removed 37.5μg/L more initial silver and had 1.1μg/L more silver in the filtrate than rainwater. Initially, filters achieved 1.9 log reduction values (LRVs) on average, but among different silver and water types this varied by as much as 2.5 LRV units. Overall, bacterial removal effectiveness was more challenging to evaluate, but some data suggest that the branched polyethylenimine silver nanoparticles provided improved initial bacterial removal over filters which were not painted with silver nanoparticles (p-value 0.038). Copyright © 2016 Elsevier B.V. All rights reserved.

Silver removal from aqueous solution by biochar produced from biosolids via microwave pyrolysis.

PubMed

Antunes, Elsa; Jacob, Mohan V; Brodie, Graham; Schneider, Philip A

2017-12-01

The contamination of water with silver has increased due to the widespread applications of products with silver employed as antimicrobial agent. Adsorption is a cost-effective method for silver removal from aqueous solution. In this study biochar, produced from the microwave assisted pyrolysis of biosolids, was used for silver removal from an aqueous solution. The adsorption kinetics, isotherms and thermodynamics were investigated to better understand the silver removal process by biochar. X-ray diffraction results demonstrated that silver removal was a combination two consecutive mechanisms, reduction and physical adsorption. The Langmuir model fitted the experimental data well, showing that silver removal was predominantly a surface mechanism. The thermodynamic investigation demonstrated that silver removal by biochar was an exothermic process. The final nanocomposite Ag-biochar (biochar plus silver) was used for methylene blue adsorption and photodegradation. This study showed the potential of using biochar produced from biosolids for silver removal as a promising solution to mitigate water pollution and an environmentally sustainable approach for biosolids management and re-use. Copyright © 2017 Elsevier Ltd. All rights reserved.

An investigation of in vivo wound healing activity of biologically synthesized silver nanoparticles

NASA Astrophysics Data System (ADS)

Kaler, Abhishek; Mittal, Amit Kumar; Katariya, Mahesh; Harde, Harshad; Agrawal, Ashish Kumar; Jain, Sanyog; Banerjee, Uttam Chand

2014-09-01

Therapeutic use of nano-silver is claimed to have reduced side effects and enhanced curative activity as compared to its ionic counterpart (silver ions). The present work aims to screen microbes for the synthesis of silver nanoparticles (AgNPs), to formulate the nano-silver-based Carbopol gel and evaluating its wound healing efficacy on rat model. The goal was to develop the topical formulation based on bio-nano-silver to control the infection and healing the wounds with higher efficacy. Procedure involved the use of Saccharomyces boulardii for the synthesis of silver nanoparticles in the size range of 3-10 nm and these nanoparticles were used for the preparation of Carbopol-based nano-silver gel. Highly stable Carbopol nanogel was developed with good rheological properties. The burn wound healing potential of this nano-silver gel was evaluated on SD rats via visual observation, transepidermal water loss and histology of skin. Excellent wound healing was observed with AgNPs. Biologically synthesized AgNPs-based nano-silver gel showed superior wound healing efficacy as compared to marketed formulations and silver ions.

Branchial versus intestinal silver toxicity and uptake in the marine teleost Parophrys vetulus.

PubMed

Grosell, M; Wood, C M

2001-10-01

Exposure to elevated waterborne silver as AgNO3 (4.07 microM=448 microg l(-1)) in seawater resulted in osmoregulatory disturbance in the lemon sole (Parophrys vetulus). The main effects were increased plasma Na+ and Cl- concentrations which translated into increased plasma osmolality. Plasma Mg2+ levels were also slightly increased after 96 h exposure. Using radioisotopic flux measurements, a 50% reduction in branchial unidirectional Na+ extrusion was observed after 48 h silver exposure. By applying an intestinal perfusion approach, we were able to separate and thus quantify the intestinal contribution to the observed silver-induced physiological disturbance and internal silver accumulation. This analysis revealed that the intestinal contribution to silver-induced ionoregulatory toxicity was as high as 50-60%. In marked contrast, internal silver accumulation (in liver and kidney) was found to be derived exclusively from uptake across the gills. Drinking of silver-contaminated seawater resulted in substantial silver accumulation in the intestinal tissue (but apparently not silver uptake across the intestine), which probably explains the intestinal contribution to silver-induced physiological disturbance.

[Research Progress of Raman Spectroscopy on Dyestuff Identification of Ancient Relics and Artifacts].

PubMed

He, Qiu-ju; Wang, Li-qin

2016-02-01

As the birthplace of Silk Road, China has a long dyeing history. The valuable information about the production time, the source of dyeing material, dyeing process and preservation status were existed in organic dyestuff deriving from cultural relics and artifacts. However, because of the low contents, complex compositions and easily degraded of dyestuff, it is always a challenging task to identify the dyestuff in relics analyzing field. As a finger-print spectrum, Raman spectroscopy owns unique superiorities in dyestuff identification. Thus, the principle, characteristic, limitation, progress and development direction of micro-Raman spectroscopy (MRS/µ-Raman), near infrared reflection and Fourier transform Raman spectroscopy (NIR-FT-Raman), surface-enhanced Raman spectroscopy (SERS) and resonance raman spectroscopy (RRS) have been introduced in this paper. Furthermore, the features of Raman spectra of gardenia, curcumin and other natural dyestuffs were classified by MRS technology, and then the fluorescence phenomena of purpurin excitated with different wavelength laser was compared and analyzed. At last, gray green silver colloidal particles were made as the base, then the colorant of madder was identified combining with thin layer chromatography (TLC) separation technology and SERS, the result showed that the surface enhancement effect of silver colloidal particles could significantly reduce fluorescence background of the Raman spectra. It is pointed out that Raman spectroscopy is a rapid and convenient molecular structure qualitative methodology, which has broad application prospect in dyestuff analysis of cultural relics and artifacts. We propose that the combination of multi-Raman spectroscopy, separation technology and long distance transmission technology are the development trends of Raman spectroscopy.

Argyria secondary to ingestion of homemade silver solution.

PubMed

Brandt, Douglas; Park, Betty; Hoang, Mai; Jacobe, Heidi T

2005-08-01

Argyria is a rare skin disease caused by cutaneous deposition of silver granules in the skin as a result of exposure to silver substrate or ingestion of silver salt. This report describes a patient with generalized argyria caused by ingestion of homemade colloidal silver solution. The patient learned about the uses of the silver solution and its preparation at a convention for "natural medicine."

Biopersistence of silver nanoparticles in tissues from Sprague–Dawley rats

PubMed Central

2013-01-01

Silver nanoparticles are known to be distributed in many tissues after oral or inhalation exposure. Thus, understanding the tissue clearance of such distributed nanoparticles is very important to understand the behavior of silver nanoparticles in vivo. For risk assessment purposes, easy clearance indicates a lower overall cumulative toxicity. Accordingly, to investigate the clearance of tissue silver concentrations following oral silver nanoparticle exposure, Sprague–Dawley rats were assigned to 3 groups: control, low dose (100 mg/kg body weight), and high dose (500 mg/kg body weight), and exposed to two different sizes of silver nanoparticles (average diameter 10 and 25 nm) over 28 days. Thereafter, the rats were allowed to recover for 4 months. Regardless of the silver nanoparticle size, the silver content in most tissues gradually decreased during the 4-month recovery period, indicating tissue clearance of the accumulated silver. The exceptions were the silver concentrations in the brain and testes, which did not clear well, even after the 4-month recovery period, indicating an obstruction in transporting the accumulated silver out of these tissues. Therefore, the results showed that the size of the silver nanoparticles did not affect their tissue distribution. Furthermore, biological barriers, such as the blood–brain barrier and blood-testis barrier, seemed to play an important role in the silver clearance from these tissues. PMID:24059869

X-Ray Absorption Near-Edge Structure (XANES) Spectroscopy Study of the Interaction of Silver Ions with Staphylococcus aureus, Listeria monocytogenes, and Escherichia coli

PubMed Central

Zanzen, Ulrike; Krishna, Katla Sai; Hormes, Josef

2013-01-01

Silver ions are widely used as antibacterial agents, but the basic molecular mechanism of this effect is still poorly understood. X-ray absorption near-edge structure (XANES) spectroscopy at the Ag LIII, S K, and P K edges reveals the chemical forms of silver in Staphylococcus aureus and Escherichia coli (Ag+ treated). The Ag LIII-edge XANES spectra of the bacteria are all slightly different and very different from the spectra of silver ions (silver nitrate and silver acetate), which confirms that a reaction occurs. Death or inactivation of bacteria was observed by plate counting and light microscopy. Silver bonding to sulfhydryl groups (Ag-S) in cysteine and Ag-N or Ag-O bonding in histidine, alanine, and dl-aspartic acid was detected by using synthesized silver-amino acids. Significantly lower silver-cysteine content, coupled with higher silver-histidine content, in Gram-positive S. aureus and Listeria monocytogenes cells indicates that the peptidoglycan multilayer could be buffering the biocidal effect of silver on Gram-positive bacteria, at least in part. Bonding of silver to phosphate groups was not detected. Interaction with DNA or proteins can occur through Ag-N bonding. The formation of silver-cysteine can be confirmed for both bacterial cell types, which supports the hypothesis that enzyme-catalyzed reactions and the electron transport chain within the cell are disrupted. PMID:23934494

Accuracy, precision, usability, and cost of portable silver test methods for ceramic filter factories.

PubMed

Meade, Rhiana D; Murray, Anna L; Mittelman, Anjuliee M; Rayner, Justine; Lantagne, Daniele S

2017-02-01

Locally manufactured ceramic water filters are one effective household drinking water treatment technology. During manufacturing, silver nanoparticles or silver nitrate are applied to prevent microbiological growth within the filter and increase bacterial removal efficacy. Currently, there is no recommendation for manufacturers to test silver concentrations of application solutions or filtered water. We identified six commercially available silver test strips, kits, and meters, and evaluated them by: (1) measuring in quintuplicate six samples from 100 to 1,000 mg/L (application range) and six samples from 0.0 to 1.0 mg/L (effluent range) of silver nanoparticles and silver nitrate to determine accuracy and precision; (2) conducting volunteer testing to assess ease-of-use; and (3) comparing costs. We found no method accurately detected silver nanoparticles, and accuracy ranged from 4 to 91% measurement error for silver nitrate samples. Most methods were precise, but only one method could test both application and effluent concentration ranges of silver nitrate. Volunteers considered test strip methods easiest. The cost for 100 tests ranged from 36 to 1,600 USD. We found no currently available method accurately and precisely measured both silver types at reasonable cost and ease-of-use, thus these methods are not recommended to manufacturers. We recommend development of field-appropriate methods that accurately and precisely measure silver nanoparticle and silver nitrate concentrations.

Silver Dissolution and Release from Ceramic Water Filters.

PubMed

Mittelman, Anjuliee M; Lantagne, Daniele S; Rayner, Justine; Pennell, Kurt D

2015-07-21

Application of silver nanoparticles (nAg) or silver nitrate (AgNO3) has been shown to improve the microbiological efficacy of ceramic water filters used for household water treatment. Silver release, however, can lead to undesirable health effects and reduced filter effectiveness over time. The objectives of this study were to evaluate the contribution of nanoparticle detachment, dissolution, and cation exchange to silver elution, and to estimate silver retention under different influent water chemistries. Dissolved silver (Ag(+)) and nAg release from filter disks painted with 0.03 mg/g casein-coated nAg or AgNO3 were measured as a function of pH (5-9), ionic strength (1-50 mM), and cation species (Na(+), Ca(2+), Mg(2+)). Silver elution was controlled by dissolution as Ag(+) and subsequent cation exchange reactions regardless of the applied silver form. Effluent silver levels fell below the drinking water standard (0.1 mg/L) after flushing with 30-42 pore volumes of pH 7, 10 mM NaNO3 at pH 7. When the influent water was at pH 5, contained divalent cations or 50 mM NaNO3, silver concentrations were 5-10 times above the standard. Our findings support regular filter replacement and indicate that saline, hard, or acidic waters should be avoided to minimize effluent silver concentrations and preserve silver treatment integrity.

Preliminary flight prototype silver ion monitoring system

NASA Technical Reports Server (NTRS)

Brady, J.

1974-01-01

The design, fabrication, and testing of a preliminary flight prototype silver ion monitoring system based on potentiometric principles and utilizing a solid-state silver sulfide electrode paired with a pressurized double-junction reference electrode housing a replaceable electrolyte reservoir is described. The design provides automatic electronic calibration utilizing saturated silver bromide solution as a silver ion standard. The problem of loss of silver ion from recirculating fluid, its cause, and corrective procedures are reported. The instability of the silver sulfide electrode is discussed as well as difficulties met in implementing the autocalibration procedure.

Photochemical Synthesis of Silver Nanodecahedrons and Related Nanostructures for Plasmonic Field Enhancement Applications

NASA Astrophysics Data System (ADS)

Lu, Haifei

Noble-metal nanocrystals have received considerable attention in recent years for their size and shape dependent localized surface Plasmon resonances (LSPR). Various applications based on colloidal nanoparticles, such as surface enhanced Raman scattering (SERS), surface enhanced fluorescence (SEF), plasmonic sensing, photothermal therapy etc., have been broadly explored in the field of biomedicine, because of their extremely large optical scattering and absorption cross sections, as well as giant electric field enhancement on their surface. However, despite its high chemical stability, gold exhibits quite large losses and electric field enhancement is comparatively weaker than silver. Silver nanoparticles synthesized by the traditional technique only cover an LSPR ranged from 420~500 nm. On the other hand, the range of 500~660 nm, which is covered by several easily available commercial laser lines, very limited colloidal silver nanostructures with controllable size and shape have been reported, and realization of tuning the resonance to longer wavelengths is very important for the practical applications. In this thesis, a systematic study on photochemical synthesis of silver nanodecahedrons (NDs) and related nanostructures, and their plasmonic field enhancements are presented. First, the roles of chemicals and the light source during the formation of silver nanoparticles have been studied. We have also developed a preparation route for the production size-controlled silver nanodecahedrons (LSPR range 420 ~ 660 nm) in high purity. Indeed our experiments indicate that both the chemicals and the light sources can affect the shape and purity of final products. Adjusting the molar ratio between sodium citrate and silver nitrate can help to control the crystal structure following rapid reduction from sodium borohydride. Light from a blue LED (465 nm) can efficiently transform the polyvinylpyrrolidone stabilized small silver nanoparticles into silver NDs through photo excitation. These silver NDs acting as seeds can be re-grown into larger silver NDs with LSPR ranging from 490 nm to 590 nm, upon receiving LED irradiation with emission close to the LSPR of silver ND seeds, which are suspended in a precursor solution containing small silver nanoparticles. With the aid of centrifugation, silver NDs with high purity can be obtained. Furthermore, silver ND with a broad tuning range (LSPR 490 ~ 660 nm) can be synthesized from these seeds using irradiation from a 500 nm LED. Second, the optical properties of silver NDs and their SERS application for sensitive molecular detection are presented. Raman signal obtained from silver NDs show remarkable advantage over noble nanoparticles of other shaped, thus revealing their strong localized field enhancement. Experimental results demonstrate that average enhancement factor from individual silver ND may be as high as 106. In order to explore their application for biosensing and bioimaging, stable silica coated SERS tags based on silver ND producing high Raman intensity have been studied. Our experiment results indicate that 10-8 M 4-MBA in solution can be detected by silver NDs modified silicon chip through SERS. Simulation result on the geometry of silver ND/silica spacer/gold film/substrate shows that the Raman sensitivity of the NDs modified chip can be further improved with the insertion of a dielectric/conductor film between them. Finally, we present a photochemical method for the preparation of silver nanostructures preparation with the use of 633 nm laser. Silver nanostructures composed of silver nanoplates could be grown from small silver nanoparticles deposited on a glass substrate. The periodicity of the silver nanostructures is several micrometers, revealing that this photochemical method has the potential for "writing" silver pattern on a solid substrate. Raman spectroscopy has also been explored for real-time monitoring of silver nanostructure growth and SERS hotspots formation.

Antibacterial Effect of Silver Diamine Fluoride on Cariogenic Organisms.

PubMed

Lou, Yali; Darvell, Brain W; Botelho, Michael G

2018-05-01

To screen the possible antimicrobial activity of a range of clinically used, silver-based compounds on cariogenic organisms: silver diamine fluoride (SDF), silver fluoride, and silver nitrate. Preliminary screening disk-diffusion susceptibility tests were conducted on Mueller-Hinton agar plates inoculated with Streptococcus mutans, Lactobacillus acidophilus, and Actinomyces naeslundii, organisms known to be cariogenic. In order to identify which component of the silver compounds was responsible for any antibacterial (AB) effect, and to provide controls, the following were also investigated at high and low concentrations: sodium fluoride, ammonium fluoride, ammonium chloride, sodium fluoride, sodium chloride, and sodium nitrate, as well as deionized water as control. A volume of 10 pL of a test solution was dispensed onto a paper disk resting on the inoculated agar surface, and the plate incubated anaerobically at 37°C for 48 hours. The zones of inhibition were then measured. Silver diamine fluoride, silver fluoride, silver nitrate, and ammonium fluoride had significant AB effect (p < 0.05) on all three test organisms, although ammonium fluoride had no effect at low concentration; the remaining other compounds had no effect. Silver ions appear to be the principal AB agent at both high and low concentration; fluoride ions only have an AB effect at high concentration, while ammonium, nitrate, chloride and sodium ions have none. The anticaries effect of topical silver solutions appears restricted to that of the silver ions. Silver compounds, such as SDF, silver fluoride, and silver nitrate have AB effect against cariogenic organisms and these may have clinical impact in arresting or preventing dental decay. Sodium fluoride did not have AB effect under the conditions tested.

The concentration effect of capping agent for synthesis of silver nanowire by using the polyol method

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

Lin, Jian-Yang; Hsueh, Yu-Lee; Huang, Jung-Jie, E-mail: jjhuang@mdu.edu.tw

2014-06-01

Silver nanowires were synthesized by the polyol method employing ethylene glycol, Poly(N-vinylpyrrolidone) (PVP) and silver nitrate (AgNO{sub 3}) as the precursors. Most of the studies used metal salts (PtCl{sub 2}, NaCl) as seed precursor to synthesize the silver nanowires. In the study, the metal salts were not used and the concentration of capping agent was changed to observe the aspect ratio of silver nanowires. The experimental results showed that controlling synthesis temperature, Poly(N-vinylpyrrolidone) (PVP) molecular weight, reactant concentrations, and addition rates of AgNO{sub 3} affects the growth characteristics of silver nanowires. Field-emission scanning electron microscopy, UV–vis spectrophotometry, and X-ray diffractometrymore » were employed to characterize the silver nanowires. As increasing the concentration of PVP, the silver nanowire diameter widened and resulted in a smaller aspect ratio. We successfully prepared silver nanowires (diameter: 170 nm, length: 20 μm). The silver nanowire thin film suspension showed high transmittance, low sheet resistance, and may be used for transparent conductive film applications. - Graphical abstract: The FE-SEM image shows that nanostructures with considerable quantities of silver nanowires can also be produced when the PVP (Mw=360 K)/AgNO{sub 3} molar ratio was 2.5. - Highlights: • The polyol method was used to synthesize of silver nanowire. • The metal seed precursors were not used before synthesizing the silver nanowires. • The silver nanowire diameter and length was 170 nm and 20 μm, respectively. • Silver nanowire film with high transmittance (>85%) and low sheet resistance (<110 Ω/sq)« less

XPS characterization of silver exchanged ETS-10 and mordenite molecular sieves.

PubMed

Anson, A; Maham, Y; Lin, C C H; Kuznicki, T M; Kuznicki, S M

2009-05-01

Silver exchanged molecular sieves ETS-10 (Ag-ETS-10) and mordenite (Ag-mordenite) were dehydrated under vacuum at temperatures between 100 degrees C-350 degrees C. Changes in the state of the silver were studied using X-ray photoelectron spectroscopy (XPS). Silver cations in titanosilicate Ag-ETS-10 are fully reduced to Ag(0) at temperatures as low as 150 degrees C. The characteristic features of the XPS spectrum of silver in this Ag-ETS-10 species correspond to only metallic silver. The signal for metallic silver is not observed in the XPS spectrum of aluminosilicate Ag-mordenite, indicating that silver cations are not reduced, even after heating to 350 degrees C.

The dual role of silver during silicon etching in HF solution

PubMed Central

2012-01-01

It was reported that during silicon etching, silver was subjected to have a controversial role. Some researchers debate that silver protects silicon, and, at the same time, other ones confirm that silver catalyzes silicon underneath. In this paper, we give experimental results arguing the dual role that silver has during the formation of silicon nanostructures. We give a proof that the role of silver depends on the experimental details and the intrinsic properties of silver during its deposition on the silicon wafer. Through our investigations, we tracked the silver particles that indicated which mechanism is involved. Characterizations of the prepared samples were made using a scanning electron microscope. PMID:22888998

Antibacterial potency of V.A.C. GranuFoam Silver(®) Dressing.

PubMed

Sachsenmaier, Saskia; Peschel, Andreas; Ipach, Ingmar; Kluba, Torsten

2013-10-01

V.A.C.(®) GranuFoam™ therapy is regularly used in the surgical therapy of infected wounds and soft tissue injuries. Silver nanoparticles can destroy bacterial cell walls and inhibit enzymes for cell replication. Silver dressings are therefore successfully used for many indications in wound therapy. In this study, we investigated the antimicrobial potency of ionic silver released from the silver-coated V.A.C.(®) GranuFoam™ during vacuum therapy. Silver dressing was exposed to agar plates populated with bacteria to measure silver release. A total of 15 agar plates colonised with either Staphylococcus aureus populations or with Staphylococcus epidermidis, were loaded with V.A.C. GranuFoam Silver(®) Dressing polyurethane foam (KCI, San Antonio, Texas). Each of 13 pieces of silver-coated foam was applied to an agar plate. Two plates were loaded with conventional black foam without any coating. After connecting to a vacuum pump, the vacuum therapy of the 15 plates lasted 5 days. The zone of inhibition of bacterial growth around the foam was measured daily. Silver release was also determined as a function of time. At each time point, there was evidence of silver in the agar independent of bacterial colonisation. The S. aureus agar showed a consecutive increase in silver concentration from baseline upon 48 h after exposure to the negative pressure of V.A.C. therapy. An increasing mean silver level after 48, 72 and 96 h was measured under V.A.C. therapy with a peak value after 120 h. In contrast, the results from the S. epidermidis plates did not follow a linear pattern. At the beginning of vacuum therapy, we documented a rise in silver concentration. After 48-96h, the silver levels fluctuated. A maximum zone of inhibition in both bacterial colonised plates (S. aureus and S. epidermidis) was found 39 h after the start of the V.A.C. GranuFoam Silver(®) therapy. From our results, we confirmed the antimicrobial effect of the silver ions against S. aureus and S. epidermidis under continuous V.A.C. GranuFoam(®) Silver therapy with a negative pressure of 25 mmHg. Furthermore we could quantify the amounts of silver, which were released from the foam under negative pressure as a function of time. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of silver-doping on the crystal structure, morphology and photocatalytic activity of TiO2 nanofibers

NASA Astrophysics Data System (ADS)

Barakat, N. A. M.; Kim, H. Y.

2012-09-01

In this study, effect of sliver-doping on the crystal structure, the nanofibrous morphology and the photocatalytic activity of titanium oxide nanofibers have been investigated. Silver-doped TiO2 nanofibers having different silver contents were prepared by calcination of electrospun nanofiber mats consisting of silver nitrate, titanium isopropoxide and poly(vinyl acetate) at 600 °C. The results affirmed formation of silver-doped TiO2 nanofibers composed of anatase and rutile when the silver nitrate content in the original electrospun solution was more than 3 wt%. The rutile phase content was directly proportional with the AgNO3 concentration in the electrospun solution. Negative impact of the silver-doping on the nanofibrous morphology was observed as increase the silver content caused to decrease the aspect ratio, i.e. producing nanorods rather nanofibers. However, silver-doping leads to modify the surface roughness. Study of the photocatalytic degradation of methylene blue dye clarified that increase the silver content strongly enhances the dye oxidation process.

Electrically Conductive Silver Paste Obtained by Use of Silver Neodecanoate as Precursor

NASA Astrophysics Data System (ADS)

Shen, Longguang; Liu, Jianguo; Zeng, Xiaoyan; Ren, Zhao

2015-02-01

An electrically conductive silver paste has been prepared from an organometallic compound, silver neodecanoate, as silver precursor. The precursor was highly soluble in organic solvents and decomposed into metallic silver at low sintering temperatures (<200°C). Thermogravimetric analysis showed the silver content of the paste was approximately 25 wt.%. Viscosity studies indicated the paste was a pseudoplastic liquid with viscosity in the range 6.5-9 Pa s. The paste was compatible with the micro-pen direct-writing process, enabling production of silver lines on a substrate. The electrical resistivity of the silver lines was 9 × 10-6 Ω cm after sintering at 115°C for 60 min, 5.8 × 10-6 Ω cm when sintered at 150°C for 60 min, and 3 × 10-6 Ω cm when sintered above 300°C, values which are similar to those of bulk silver. Hence, the prepared paste can be successfully used on flexible substrates such as polymers.

Automotive Stirling engine development program

NASA Technical Reports Server (NTRS)

Ernst, W.; Richey, A.; Farrell, R.; Riecke, G.; Smith, G.; Howarth, R.; Cronin, M.; Simetkosky, M.; Meacher, J.

1986-01-01

This is the ninth Semiannual Technical Progress Report prepared under the Automotive Stirling Engine Development Program. It covers the twenty-eighth and twenty-ninth quarters of activity after award of the contract. Quarterly Technical Progress Reports related program activities from the first through the thirteenth quarters; thereafter, reporting was changed to a Semiannual format. This report summarizes the study of higher-power kinematic Stirling engines for transportation use, development testing of Mod I Stirling engines, and component development activities. Component development testing included successful conical fuel nozzle testing and functional checkout of Mod II controls and auxiliaries on Mod I engine test beds. Overall program philosophy is outlined and data and test results are presented.

Publications of the Jet Propulsion Laboratory, 1981

NASA Technical Reports Server (NTRS)

1982-01-01

Over 500 externally distributed technical reports released during 1981 that resulted from scientific and engineering work performed, or managed by Jet Propulsion Laboratory are listed by primary author. Of the total number of entries, 311 are from the bimonthly Deep Space Network Progress Report, and its successor, the Telecommunications and Data Acquisition Progress Report.

40 CFR 35.4170 - What kinds of reporting does EPA require?

Code of Federal Regulations, 2011 CFR

2011-07-01

... OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Grants for Technical Assistance Managing Your Tag... period which ends June 30 and December 31 of each year. (b) [Reserved] (c) Progress Report Full description in chart or narrative format of the progress your group made in relation to your approved schedule...

77 FR 75441 - Healthy Home and Lead Hazard Control Grant Programs Data Collection; Progress Reporting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-20

... DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT [Docket No. FR-5603-N-93] Healthy Home and Lead Hazard... collection is designed to provide HUD timely information on progress of Healthy Homes Demonstration Program, Healthy Homes Technical Studies Program, Lead Base paint Hazard Control program, Lead Hazard Reduction...

Measuring Student Progress in the Classroom: A Guide to Testing and Evaluating Progress of Students with Disabilities.

ERIC Educational Resources Information Center

Hartman, Rhona C.; Redden, Martha Ross

This fact sheet provides guidelines on adapting testing situations for disabled postsecondary students. Discussed in the first section are considerations in determining when testing adaptations are needed including disability verification procedures, policy consistency, and maintenance of academic and technical standards. Facts about disabilities…

Progress in the First Five Years: An Evaluation of Achieving the Dream Colleges in Washington State

ERIC Educational Resources Information Center

Jenkins, Davis; Wachen, John; Kerrigan, Monica Reid; Mayer, Alexander K.

2012-01-01

In 2006, six community and technical colleges in Washington State joined the innovative national reform initiative called Achieving the Dream (ATD). This report describes the progress each college made in implementing ATD's "culture of evidence" principles for institutional improvement, examines strategies implemented by the colleges to…

Effect of pulsed progressive fluoroscopy on reduction of radiation dose in the cardiac catheterization laboratory

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

Holmes, D.R. Jr.; Wondrow, M.A.; Gray, J.E.

1990-01-01

The increased application of therapeutic interventional cardiology procedures is associated with increased radiation exposure to physicians, patients and technical personnel. New advances in imaging techniques have the potential for reducing radiation exposure. A progressive scanning video system with a standard vascular phantom has been shown to decrease entrance radiation exposure. The effect of this system on reducing actual radiation exposure to physicians and technicians was assessed from 1984 through 1987. During this time, progressive fluoroscopy was added sequentially to all four adult catheterization laboratories; no changes in shielding procedures were made. During this time, the case load per physician increasedmore » by 63% and the number of percutaneous transluminal coronary angioplasty procedures (a high radiation procedure) increased by 244%. Despite these increases in both case load and higher radiation procedures, the average radiation exposure per physician declined by 37%. During the same time, the radiation exposure for technicians decreased by 35%. Pulsed progressive fluoroscopy is effective for reducing radiation exposure to catheterization laboratory physicians and technical staff.« less

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.

Synthesis and characterization of silver nanowires with zigzag morphology in N, N-dimethylformamide

NASA Astrophysics Data System (ADS)

He, Xin; Zhao, Xiujian; Chen, Yunxia; Feng, Jinyang; Sun, Zhenya

2007-08-01

Zigzag silver nanowires with a uniform diameter of 20±5 nm were prepared by reducing silver nitrate (AgNO 3) with N, N-dimethylformamide (DMF) in the presence of tetrabutyl titanate (TBT) and acetylacetone (AcAc) at 373 K for 18 h. X-ray and selected area electron diffraction (XRD and SAED) patterns reveal that the prepared product is made of pure silver with face centered cubic structure. Transmission electron microscopy (TEM) investigations suggest that the amount of silver nanowires is enhanced with increase in reaction time, and the end-to-end assemblies of silver nanorods are observed during the reaction process. After 18 h reaction, silver nanowires with zigzag morphology are obtained. In this paper, a possible growth process of silver nanowires with this interesting shape is described. Silver nanoparticles with small sizes were obtained by reducing Ag + ions with DMF, providing seeds for homogeneous growth of silver nanorods. With the extending reaction time, the synthesized silver nanorods were connected in an end-to-end manner, and the interface between the connections of two nanorods gradually disappeared. The final product shows zigzag morphology with various angles. The angles between two connecting straight parts of zigzag nanowires exhibit an alterable range of 74-151°. These silver nanowires show tremendous potential applications in future nanoscale electronic circuits.

Exposure-related health effects of silver and silver compounds: a review.

PubMed

Drake, Pamela L; Hazelwood, Kyle J

2005-10-01

A critical review of studies examining exposures to the various forms of silver was conducted to determine if some silver species are more toxic than others. The impetus behind conducting this review is that several occupational exposure limits and guidelines exist for silver, but the values for each depend on the form of silver as well as the individual agency making the recommendations. For instance, the American Conference of Governmental Industrial Hygienists has established separate threshold limit values for metallic silver (0.1 mg/m3) and soluble compounds of silver (0.01 mg/m3). On the other hand, the permissible exposure limit (PEL) recommended by the Occupational Safety and Health Administration and the Mine Safety and Health Administration and the recommended exposure limit set by the National Institute for Occupational Safety and Health is 0.01 mg/m3 for all forms of silver. The adverse effects of chronic exposure to silver are a permanent bluish-gray discoloration of the skin (argyria) or eyes (argyrosis). Most studies discuss cases of argyria and argyrosis that have resulted primarily from exposure to the soluble forms of silver. Besides argyria and argyrosis, exposure to soluble silver compounds may produce other toxic effects, including liver and kidney damage, irritation of the eyes, skin, respiratory, and intestinal tract, and changes in blood cells. Metallic silver appears to pose minimal risk to health. The current occupational exposure limits do not reflect the apparent difference in toxicities between soluble and metallic silver; thus, many researchers have recommended that separate PELs be established.

A perspective on the hemolytic activity of chemical and green-synthesized silver and silver oxide nanoparticles

NASA Astrophysics Data System (ADS)

Ashokraja, C.; Sakar, M.; Balakumar, S.

2017-10-01

We report the hemolysis properties of silver and silver oxide nanoparticles (NPs) prepared by chemical and green-synthesis methods. The prepared silver and silver oxide NPs were analyzed using UV-vis spectroscopy to confirm their formation by characterizing their surface plasmon resonance (SPR) and absorption band peaks respectively. The Fourier transmission infrared (FTIR) spectra of the materials showed the characteristic functional groups corresponding to the molecules present in leaf extracts, which is proposed to be acted as reducing and capping agents that are also found on the surface of silver and silver oxide nanoparticles that synthesized via green-synthesis method. Zeta potential analysis revealed the surface charge and stability of the prepared NPs. HRTEM images showed almost spherical shape nanoparticles with an average size of 15.2 and 31.5 nm for wet chemical synthesized silver and silver oxide nanoparticles respectively. In the case of green synthesized silver and silver oxide nanoparticles, it was observed to be 19.4 and 30.4 nm respectively. The order of hemolysis efficacy of the materials is found to be as follows: chemically synthesized Ag2O>  chemically synthesized Ag NPs followed by green-synthesized Ag2O and green-synthesized Ag NPs which showed almost similar hemolysis with respect to concentration. The relatively stable nature of the silver NPs could be attributed to their lower hemolysis efficacy, while the increased lysis properties of silver oxide could be attributed due to reductive/oxidative processes that give rise to the hemolysis through interfacial charge interactions with RBCs.

Characterization of engineered nanoparticles in commercially available spray disinfectant products advertised to contain colloidal silver

EPA Science Inventory

Given the potential for human exposure to silver nanoparticles from spray disinfectants and dietary supplements, we characterized the silver-containing nanoparticles in 22 commercial products that advertised the use of silver or colloidal silver as the active ingredient. Characte...

Protective Gel Composition for Treating White Phosphorus Burn Wounds.

DTIC Science & Technology

Water soluble hydrogels of alkali metal alginate and glycerin containing 0.01% to 1% cupric ( copper ) sulfate pentahydrate or silver salts such as...burns. Cupric sulfate pentahydrate of silver salts such as silver acetate, silver lactate monohydrate and silver nitrate in the gel reacts with the

A Tool for Measuring NASA's Aeronautics Research Progress Toward Planned Strategic Community Outcomes

NASA Technical Reports Server (NTRS)

Tahmasebi, Farhad; Pearce, Robert

2016-01-01

Description of a tool for portfolio analysis of NASA's Aeronautics research progress toward planned community strategic Outcomes is presented. For efficiency and speed, the tool takes advantage of a function developed in Excels Visual Basic for Applications. The strategic planning process for determining the community Outcomes is also briefly discussed. Stakeholder buy-in, partnership performance, progress of supporting Technical Challenges, and enablement forecast are used as the criteria for evaluating progress toward Outcomes. A few illustrative examples of using the tool are also presented.

Stable silver/biopolymer hybrid plasmonic nanostructures for high performance surface enhanced raman scattering (SERS)

USDA-ARS?s Scientific Manuscript database

Silver/biopolymer nanoparticles were prepared by adding 100 mg silver nitrate to 2% polyvinyl alcohol solution and reduced the silver nitrate into silver ion using 2 % trisodium citrate for high performance Surface Enhanced Raman Scattering (SERS) substrates. Optical properties of nanoparticle were ...

Mechanism of Silver Sulfadiazine Action on Burn Wound Infections

PubMed Central

Fox, Charles L.; Modak, Shanta M.

1974-01-01

The role of silver and sulfadiazine in the mechanism of action of silver sulfadiazine on burn wound infections was investigated. Silver, but not sulfadiazine, was bound by bacteria. Sulfadiazine did not act as an antibacterial agent in low concentrations, but exhibited specific synergism in combination with subinhibitory levels of silver sulfadiazine. The efficacy of silver sulfadiazine is thought to result from its slow and steady reactions with serum and other sodium chloride-containing body fluids, which permits the slow and sustained delivery of silver ions into the wound environs. In this circumstance, a relatively minute amount of sulfadiazine appears active. PMID:15825409

Synthesis and characterization of bactericidal silver nanoparticles using cultural filtrate of simulated microgravity grown Klebsiella pneumoniae.

PubMed

Kalpana, Duraisamy; Lee, Yang Soo

2013-03-05

Silver nanoparticles were synthesized by biological method using cultural filtrate of Klebsiella pneumoniae cultured under simulated microgravity and silver nitrate solution as precursor. The nanoparticles exhibited typical plasmon absorption maximum of silver nanoparticles between 405 and 407 nm. Spherical silver nanoparticles were found to have size between 15 and 37 nm by TEM analysis. XRD pattern corresponding to planes (111), (200), (220) (311) revealed the crystalline nature of the biosynthesized silver nanoparticles. FTIR spectrum proposed stabilization of silver nanoparticles by the protein molecules present in the cultural filtrate. The silver nanoparticles exhibited high bactericidal activity against Salmonella enterica, Escherichia coli and moderate bactericidal activity against Streptococcus pyogenes. Copyright © 2012 Elsevier Inc. All rights reserved.

Antibacterial properties of Ag-doped hydroxyapatite layers prepared by PLD method

NASA Astrophysics Data System (ADS)

Jelínek, Miroslav; Kocourek, Tomáš; Jurek, Karel; Remsa, Jan; Mikšovský, Jan; Weiserová, Marie; Strnad, Jakub; Luxbacher, Thomas

2010-12-01

Thin hydroxyapatite (HA), silver-doped HA and silver layers were prepared using a pulsed laser deposition method. Doped layers were ablated from silver/HA targets. Amorphous and crystalline films of silver concentrations of 0.06 at.%, 1.2 at.%, 4.4 at.%, 8.3 at.% and 13.7 at.% were synthesized. Topology was studied using scanning electron microscopy and atomic force microscopy. Contact angle and zeta potential measurements were conducted to determine the wettability, surface free energy and electric surface properties. In vivo measurement (using Escherichia coli cells) of antibacterial properties of the HA, silver-doped HA and silver layers was carried out. The best antibacterial results were achieved for silver-doped HA layers of silver concentration higher than 1.2 at.%.

Colloidal silver fabrication using the spark discharge system and its antimicrobial effect on Staphylococcus aureus.

PubMed

Tien, Der-Chi; Tseng, Kuo-Hsiung; Liao, Chih-Yu; Tsung, Tsing-Tshih

2008-10-01

Nanoscale techniques for silver production may assist the resurgence of the medical use of silver, especially given that pathogens are showing increasing resistance to antibiotics. Traditional chemical synthesis methods for colloidal silver (CS) may lead to the presence of toxic chemical species or chemical residues, which may inhibit the effectiveness of CS as an antibacterial agent. To counter these problems a spark discharge system (SDS) was used to fabricate a suspension of colloidal silver in deionized water with no added chemical surfactants. SDS-CS contains both metallic silver nanoparticles (Ag(0)) and ionic silver forms (Ag(+)). The antimicrobial affect of SDS-CS on Staphylococcus aureus was studied. The results show that CS solutions with an ionic silver concentration of 30 ppm or higher are strong enough to destroy S. aureus. In addition, it was found that a solution's antimicrobial potency is directly related to its level of silver ion concentration.

Sunlight-assisted synthesis of colloidal silver nanoparticles using chitosan as reducing agent

NASA Astrophysics Data System (ADS)

Susilowati, E.; Maryani; Ashadi

2018-04-01

The present study we explore an environmentally friendly colloidal silver nanoparticles preparation using chitosan as reducing agent and stabilizer. It develops a new strategy on preparation of silver nanoparticles through the gel phase using sodium hydroxide (NaOH) as accelerator reagent. Sunlight irradiation was employed to assisted reducing process of silver ions to silver nanoparticles. Localized surface plasmon resonance (LSPR) phenomenon of silver nanoparticles was investigated using UV-Vis spectrophotometer. The shape and size of silver particles were analyzed using TEM. The formation of silver nanoparticles was confirmed by the appearance of LSPR absorption peak at 396.0–412.0 nm. The absorption peak of LSPR were affected by NaOH amount, time of sulight irradiation and concentration of AgNO3. The produced silver nanoparticles were spherical with dominant size range of 5 to 8 nm as shown by TEM images. All colloidals were stable without any aggregation for 30 days after preparation.

Sintered silver joints via controlled topography of electronic packaging subcomponents

DOEpatents

Wereszczak, Andrew A.

2014-09-02

Disclosed are sintered silver bonded electronic package subcomponents and methods for making the same. Embodiments of the sintered silver bonded EPSs include topography modification of one or more metal surfaces of semiconductor devices bonded together by the sintered silver joint. The sintered silver bonded EPSs include a first semiconductor device having a first metal surface, the first metal surface having a modified topography that has been chemically etched, grit blasted, uniaxial ground and/or grid sliced connected to a second semiconductor device which may also include a first metal surface with a modified topography, a silver plating layer on the first metal surface of the first semiconductor device and a silver plating layer on the first metal surface of the second semiconductor device and a sintered silver joint between the silver plating layers of the first and second semiconductor devices which bonds the first semiconductor device to the second semiconductor device.

Ink composition for making a conductive silver structure

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

Walker, Steven B.; Lewis, Jennifer A.

An ink composition for making a conductive silver structure comprises a silver salt and a complex of (a) a complexing agent and a short chain carboxylic acid or (b) a complexing agent and a salt of a short chain carboxylic acid, according to one embodiment. A method for making a silver structure entails combining a silver salt and a complexing agent, and then adding a short chain carboxylic acid or a salt of the short chain carboxylic acid to the combined silver salt and a complexing agent to form an ink composition. A concentration of the complexing agent in themore » ink composition is reduced to form a concentrated formulation, and the silver salt is reduced to form a conductive silver structure, where the concentrated formulation and the conductive silver structure are formed at a temperature of about 120.degree. C. or less.« less

Green synthesis of silver nanoparticle and silver based chitosan bionanocomposite using stem extract of Saccharum officinarum and assessment of its antibacterial activity

NASA Astrophysics Data System (ADS)

Paulkumar, Kanniah; Gnanajobitha, Gnanadhas; Vanaja, Mahendran; Pavunraj, Manickam; Annadurai, Gurusamy

2017-09-01

Synthesis of nanoparticles and nanocomposites using green route is a major focus of modern nanotechnology. Herein we demonstrate the synthesis of silver nanoparticle and silver based chitosan bionanocomposite using the stem extract of Saccharum officinarum. The absorbance peak at 460 nm in the UV-Vis spectrum reveals the synthesis of silver nanoparticles using the stem extract of Saccharum officinarum. The size of the synthesized silver nanoparticle was in the range of 10-60 nm obtained from transmission electron microscope (TEM) analysis. The presence of silver nanoparticles on the chitosan suspension was identified by scanning electron microscope (SEM) and energy dispersive x-ray spectroscopy (EDS). The presence of possible functional group involved in the reduction of silver metal ions into silver nanoparticles was identified by Fourier transform infrared spectroscopy (FTIR) analysis. The antibacterial activity of the synthesized silver based chitosan bionanocomposite was evaluated against Bacillus subtilis (MTCC 3053), Klebsiella planticola (MTCC 2277), Streptococcus faecalis (ATCC 8043), Pseudomonas aeruginosa (ATCC 9027) and Escherichia coli (ATCC 8739). The antibacterial activity of silver based chitosan bionanocomposite has remarkable scope in medicine, food packaging, textile and pharmaceuticals.

Silver Film Surface Modification by Ion Bombardment Decreases Surface Plasmon Resonance Absorption.

PubMed

Fryauf, David M; Diaz Leon, Juan J; Phillips, Andrew C; Kobayashi, Nobuhiko P

2017-05-10

Silver thin films covered with dielectric films serving as protective coatings are desired for telescope mirrors, but durable coatings have proved elusive. As part of an effort to develop long-lived protected-silver mirrors, silver thin films were deposited by electron beam evaporation using a physical vapor deposition system at the University of California Observatories Astronomical Coatings Lab. The silver films were later covered with a stack of dielectric films utilizing silicon nitride and titanium dioxide deposited by ion-assisted electron beam evaporation to fabricate protected mirrors. In-situ argon ion bombardment was introduced after silver deposition and prior to the deposition of dielectric films to assess its effects on the performance of the mirrors. We found that ion bombardment of the silver influenced surface morphology and reflectivity, and these effects correlated with time between silver deposition and ion bombardment. The overall reflectivity at wavelengths in the range of 350-800 nm was found to improve due to ion bombardment, which was qualitatively interpreted as a result of decreased surface plasmon resonance coupling. We suggest that the observed decrease in coupling is caused by silver grain boundary pinning due to ion bombardment suppressing silver surface diffusion, forming smoother silver-dielectric interfaces.

Comparison on Bactericidal and Cytotoxic Effect of Silver Nanoparticles Synthesized by Different Methods

NASA Astrophysics Data System (ADS)

Mala, R.; Celsia, A. S. Ruby; Malathi Devi, S.; Geerthika, S.

2017-08-01

Biologically synthesized silver nanoparticle are biocompatible for medical applications. The present work is aimed to synthesize silver nanoparticle using the fruit pulp of Tamarindusindica and to evaluate its antibacterial and anticancer activity against lung cancercell lines. Antibacterial activity was assessed by well diffusion method. Cytotoxicity was evaluated using MTT assay. GC-MS of fruit pulp extract showed the presence of levoglucosenone, n-hexadecanoic acid, 9,12-octadecadienoic acid etc. Antioxidant activity of the fruit pulp was determined by DPPH assay, hydrogen peroxide scavenging assay and lipid peroxidation. The size of biologically synthesized silver nanoparticle varied from 50 nm to 76 nm. It was 59 nm to 98 nm for chemically synthesized silver nanoparticle. Biologically synthesized silver nanoparticle showed 26 mm inhibition zone against E. coli and chemically synthesized silver nanoparticle showed 20 mm. Antioxidant activity of fruit extract by DPPH showed 84 % reduction. The IC 50 of biologically synthesized silver nanoparticle against lung cancer cell lines was 48 µg/ml. It was 95 µg/ml for chemically synthesized silver nanoparticle. The increased activity of biologically synthesized silver nanoparticle was due to its smaller size, stability and the bioactive compounds capping the silver nanoparticle extracted from the fruit extract.

Selective recovery of silver from waste low-temperature co-fired ceramic and valorization through silver nanoparticle synthesis.

PubMed

Swain, Basudev; Shin, Dongyoon; Joo, So Yeong; Ahn, Nak Kyoon; Lee, Chan Gi; Yoon, Jin-Ho

2017-11-01

Considering the value of silver metal and silver nanoparticles, the waste generated during manufacturing of low temperature co-fired ceramic (LTCC) were recycled through the simple yet cost effective process by chemical-metallurgy. Followed by leaching optimization, silver was selectively recovered through precipitation. The precipitated silver chloride was valorized though silver nanoparticle synthesis by a simple one-pot greener synthesis route. Through leaching-precipitation optimization, quantitative selective recovery of silver chloride was achieved, followed by homogeneous pure silver nanoparticle about 100nm size were synthesized. The reported recycling process is a simple process, versatile, easy to implement, requires minimum facilities and no specialty chemicals, through which semiconductor manufacturing industry can treat the waste generated during manufacturing of LTCC and reutilize the valorized silver nanoparticles in manufacturing in a close loop process. Our reported process can address issues like; (i) waste disposal, as well as value-added silver recovery, (ii) brings back the material to production stream and address the circular economy, and (iii) can be part of lower the futuristic carbon economy and cradle-to-cradle technology management, simultaneously. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

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

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

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.

Career and Technical Education and Academic Progress at the End of High School: Evidence from the Education Longitudinal Study of 2002

ERIC Educational Resources Information Center

Bozick, Robert; Dalton, Ben

2013-01-01

This report examines the role of career and technical education (CTE) for assessing students in learning mathematics and preventing students from dropping out of high school. CTE is a wide field of educational practice that includes occupational training and career preparation offered in formats ranging from individual courses to comprehensive…

easyCBM[R] Mathematics Criterion Related Validity Evidence: Oregon State Test. Technical Report #1011

ERIC Educational Resources Information Center

Anderson, Daniel; Alonzo, Julie; Tindal, Gerald

2010-01-01

In this technical report, we present the results of a study examining the relation between the math measures available on the easyCBM[R] online benchmark and progress monitoring assessment system and the Oregon statewide assessment of mathematics. Designed for use within a response to intervention (RTI) framework, easyCBM[R] is intended to help…

New York City School Survey 2008-2010: Assessing the Reliability and Validity of a Progress Report Measure. Technical Appendices

ERIC Educational Resources Information Center

Nathanson, Lori; Cole, Rachel; Kemple, James J.; Lent, Jessica; McCormick, Meghan; Segeritz, Micha

2013-01-01

The Research Alliance for New York City Schools examined Department of Education (DOE) School Survey data from 2008-2010 to better understand the richness and complexities of the information elicited by the Survey from parents, students, and teachers. This document provides the appendices to the technical report "New York City School Survey…

The 1992 Research/Technology report

NASA Technical Reports Server (NTRS)

1992-01-01

The 1992 Research & Technology report is organized so that a broad cross section of the community can readily use it. A short introductory paragraph begins each article and will prove to be an invaluable reference tool for the layperson. The approximately 200 articles summarize the progress made during the year in various technical areas and portray the technical and administrative support associated with Lewis technology programs.

Trends in Articulation Arrangements for Technical and Vocational Education in the South East Asian Region.

ERIC Educational Resources Information Center

Haas, Adrian R.

Trends in articulation arrangements for technical and vocational education (TVE) in the South East Asia region were studied. A key feature of articulation is the existence of pathways that allow graduates of one course of study to progress to other courses. Effective articulation opens up advancement for individuals and helps to create a flexible…

Longitudinal Surveys of Australian Youth (LSAY) 1998 Cohort: Wave 12 (2009)--Frequency Tables. Technical Report 58B

ERIC Educational Resources Information Center

National Centre for Vocational Education Research (NCVER), 2010

2010-01-01

The Longitudinal Surveys of Australian Youth (LSAY) program studies the progress of several groups of young Australians as they move from school into post-secondary education and work. This technical paper contains the frequency tables for the LSAY 1998 cohort Wave 12 (2009) data set. [For the accompanying questionnaire, "Longitudinal Surveys…

Longitudinal Surveys of Australian Youth (LSAY): 2003 Cohort Wave 7 (2009)--Frequency Tables. Technical Report 57B

ERIC Educational Resources Information Center

National Centre for Vocational Education Research (NCVER), 2010

2010-01-01

The Longitudinal Surveys of Australian Youth (LSAY) program studies the progress of several groups of young Australians as they move from school into post-secondary education and work. This technical paper contains the frequency tables for the LSAY 2003 cohort Wave 7 (2009) data set. [For the related questionnaire, see ED512164.

Longitudinal Surveys of Australian Youth (LSAY) 2009 Cohort: Wave 3 (2011)--Frequency Tables. Technical Report 72B

ERIC Educational Resources Information Center

National Centre for Vocational Education Research (NCVER), 2012

2012-01-01

The Longitudinal Surveys of Australian Youth (LSAY) program studies the progress of several groups of young Australians as they move from school into post-secondary education and work. This technical paper contains the frequency tables for the LSAY 2009 cohort Wave 3 (2011) data set. [For the related questionnaire, see ED536306.

Longitudinal Surveys of Australian Youth (LSAY) 2003 Cohort: Wave 7 (2009)--Questionnaire. Technical Report 57A

ERIC Educational Resources Information Center

National Centre for Vocational Education Research (NCVER), 2010

2010-01-01

The Longitudinal Surveys of Australian Youth (LSAY) program studies the progress of several groups of young Australians as they move from school into post-secondary education and work. This technical paper contains the questionnaire for the LSAY 2003 cohort Wave 7 (2009) data set. [For the related frequency tables, see ED512163.

Making the Good Even Better: Feedback from easyCBM Focus Groups, School Year 2009/2010. Technical Report # 1001

ERIC Educational Resources Information Center

Alonzo, Julie; Tindal, Gerald; Lai, Cheng-Fei

2010-01-01

This technical report provides a summary of feedback from teachers, administrators, and support personnel who used the easyCBM progress monitoring and benchmark assessment system during school year 2009/2010. Data were gathered from semi-structured focus groups conducted during the 2010 easyCBM August Institute at the University of Oregon. Results…

Longitudinal Surveys of Australian Youth (LSAY): 2006 Cohort Wave 4 (2009)--Frequency Tables. Technical Report 56B

ERIC Educational Resources Information Center

National Centre for Vocational Education Research (NCVER), 2010

2010-01-01

The Longitudinal Surveys of Australian Youth (LSAY) program studies the progress of several groups of young Australians as they move from school into post-secondary education and work. This technical paper contains the frequency tables for the LSAY 2006 cohort Wave 4 (2009) data set. [For the "Longitudinal Surveys of Australian Youth (LSAY):…

Longitudinal Surveys of Australian Youth (LSAY): 2006 Cohort Wave 4 (2009)--Questionnaire. Technical Report 56A

ERIC Educational Resources Information Center

National Centre for Vocational Education Research (NCVER), 2010

2010-01-01

The Longitudinal Surveys of Australian Youth (LSAY) program studies the progress of several groups of young Australians as they move from school into post-secondary education and work. This technical paper contains the questionnaire for the LSAY 2006 cohort Wave 4 (2009) data set. [For the "Longitudinal Surveys of Australian Youth (LSAY):…

Establishment of the Center for Advanced Separation Technologies

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

Christopher E. Hull

2006-09-30

This Final Technical Report covers the eight sub-projects awarded in the first year and the five projects awarded in the second year of Cooperative Agreement DE-FC26-01NT41091: Establishment of the Center for Advanced Separation Technologies. This work is summarized in the body of the main report: the individual sub-project Technical Progress Reports are attached as Appendices.

A Historical Introduction to Library Education: Problems and Progress to 1951.

ERIC Educational Resources Information Center

White, Carl M.

The growth of libraries and of technical education in the middle of the 19th century led to the organization of Melvil Dewey's School of Library Economy in 1887. The School offered a technical course to replace the apprenticeships then in favor. Its curriculum persisted as the model for library education through 1920. A break with the early form…

Progress Report on Reactivity Analyses (October-December Test Data). Beginning Teacher Evaluation Study. Technical Note Series. Technical Note III-5.

ERIC Educational Resources Information Center

Filby, Nikola N.

The development and refinement of the measures of student achievement in reading and mathematics for the Beginning Teacher Evaluation Study are described. The concept of reactivity to instruction is introduced: the tests used to evaluate instructional processes must be sensitive indicators of classroom learning overtime. Data collection activities…

First results of ground-based LWIR hyperspectral imaging remote gas detection

NASA Astrophysics Data System (ADS)

Zheng, Wei-jian; Lei, Zheng-gang; Yu, Chun-chao; Wang, Hai-yang; Fu, Yan-peng; Liao, Ning-fang; Su, Jun-hong

2014-11-01

The new progress of ground-based long-wave infrared remote sensing is presented. The LWIR hyperspectral imaging by using the windowing spatial and temporal modulation Fourier spectroscopy, and the results of outdoor ether gas detection, verify the features of LWIR hyperspectral imaging remote sensing and technical approach. It provides a new technical means for ground-based gas remote sensing.

Review of Web-Based Technical Documentation Processes. FY07 NAEP-QA Special Study Report. TR-08-17

ERIC Educational Resources Information Center

Gribben, Monica; Wise, Lauress; Becker, D. E.

2008-01-01

Beginning with the 2000 and 2001 National Assessment of Educational Progress (NAEP) assessments, the National Center for Education Statistics (NCES) has made technical documentation available on the worldwide web at http://nces.ed.gov/nationsreportcard/tdw/. The web-based documentation is designed to be less dense and more accessible than prior…

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.

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.

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.

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

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

Professional technical standards in colleges and schools of pharmacy.

PubMed

Berry, Tricia M; Chichester, Clinton O; Lundquist, Lisa M; Sanoski, Cynthia A; Woodward, Donald A; Worley, Marcia M; Early, Johnnie L

2011-04-11

To determine the prevalence, characteristics, and use of professional technical standards among colleges and schools of pharmacy accredited by the Accreditation Council for Pharmacy Education (ACPE). The Web site of every college and school of pharmacy accredited by ACPE was searched to identify information regarding the availability, content, and use of technical standards and to obtain demographic information. Information was obtained from all of the 114 colleges and schools of pharmacy and 67 (59%) had technical standards in place. Common themes for technical standards were: observation; communication; motor; intellectual, conceptual, integrative and quantitative abilities; and behavioral and social attributes. Of those colleges and schools with technical standards, 61 (91%) had standards that addressed all 5 of these themes and 34 (51%) specified that the technical standards were used in their admission, progression, and graduation procedures. More than half of the colleges and schools of pharmacy examined in this study have technical standards; however, 41% have yet to develop and implement them. Colleges and schools of pharmacy looking for guidance in technical standards development could use the technical standards themes identified in this study.

Professional Technical Standards in Colleges and Schools of Pharmacy

PubMed Central

Berry, Tricia M.; Chichester, Clinton O.; Sanoski, Cynthia A.; Woodward, Donald A.; Worley, Marcia M.; Early, Johnnie L.

2011-01-01

Objective To determine the prevalence, characteristics, and use of professional technical standards among colleges and schools of pharmacy accredited by the Accreditation Council for Pharmacy Education (ACPE). Methods The Web site of every college and school of pharmacy accredited by ACPE was searched to identify information regarding the availability, content, and use of technical standards and to obtain demographic information. Results Information was obtained from all of the 114 colleges and schools of pharmacy and 67 (59%) had technical standards in place. Common themes for technical standards were: observation; communication; motor; intellectual, conceptual, integrative and quantitative abilities; and behavioral and social attributes. Of those colleges and schools with technical standards, 61 (91%) had standards that addressed all 5 of these themes and 34 (51%) specified that the technical standards were used in their admission, progression, and graduation procedures. Conclusion More than half of the colleges and schools of pharmacy examined in this study have technical standards; however, 41% have yet to develop and implement them. Colleges and schools of pharmacy looking for guidance in technical standards development could use the technical standards themes identified in this study. PMID:21655404

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…

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…

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.

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.

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.

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.

Economic growth and decline in mortality in developing countries: an analysis of the World Bank development datasets.

PubMed

Renton, A; Wall, M; Lintott, J

2012-07-01

The 1999 World Bank report claimed that growth in gross domestic product (GDP) between 1960 and 1990 only accounted for 15% of concomitant growth in life expectancy in developing countries. These findings were used repeatedly by the World Health Organization (WHO) to support a policy shift away from promoting social and economic development, towards vertical technology-driven programmes. This paper updates the 1999 World Bank report using the World Bank's 2005 dataset, providing a new assessment of the relative contribution of economic growth. Time-series analysis. Cross-sectional time-series regression analysis using a random effect model of associations between GDP, education and technical progress and improved health outcomes. The proportion of improvement in health indicators between 1970 and 2000 associated with changes in GDP, education and technical progress was estimated. In 1970, a 1% difference in GDP between countries was associated with 6% difference in female (LEBF) and 5% male (LEBM) life expectancy at birth. By 2000, these values had increased to 14% and 12%, explaining most of the observed health gain. Excluding Europe and Central Asia, the proportion of the increase in LEBF and LEBM attributable to increased GDP was 31% and 33% in the present analysis, vs. 17% and 14%, respectively, estimated by the World Bank. In the poorest countries, higher GDPs were required in 2000 than in 1970 to achieve the same health outcomes. In the poorest countries, socio-economic change is likely to be a more important source of health improvement than technical progress. Technical progress, operating by increasing the size of the effect of a unit of GDP on health, is likely to benefit richer countries more than poorer countries, thereby increasing global health inequalities. Copyright © 2012 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Critical Review of Technical Questions Facing Low Impact Development and Green Infrastructure: A Perspective from the Great Plains.

PubMed

Vogel, Jason R; Moore, Trisha L; Coffman, Reid R; Rodie, Steven N; Hutchinson, Stacy L; McDonough, Kelsey R; McLemore, Alex J; McMaine, John T

2015-09-01

Since its inception, Low Impact Development (LID) has become part of urban stormwater management across the United States, marking progress in the gradual transition from centralized to distributed runoff management infrastructure. The ultimate goal of LID is full, cost-effective implementation to maximize watershed-scale ecosystem services and enhance resilience. To reach that goal in the Great Plains, the multi-disciplinary author team presents this critical review based on thirteen technical questions within the context of regional climate and socioeconomics across increasing complexities in scale and function. Although some progress has been made, much remains to be done including continued basic and applied research, development of local LID design specifications, local demonstrations, and identifying funding mechanisms for these solutions. Within the Great Plains and beyond, by addressing these technical questions within a local context, the goal of widespread acceptance of LID can be achieved, resulting in more effective and resilient stormwater management.

Do failures in non-technical skills contribute to fatal medical accidents in Japan? A review of the 2010-2013 national accident reports.

PubMed

Uramatsu, Masashi; Fujisawa, Yoshikazu; Mizuno, Shinya; Souma, Takahiro; Komatsubara, Akinori; Miki, Tamotsu

2017-02-16

We sought to clarify how large a proportion of fatal medical accidents can be considered to be caused by poor non-technical skills, and to support development of a policy to reduce number of such accidents by making recommendations about possible training requirements. Summaries of reports of fatal medical accidents, published by the Japan Medical Safety Research Organization, were reviewed individually. Three experienced clinicians and one patient safety expert conducted the reviews to determine the cause of death. Views of the patient safety expert were given additional weight in the overall determination. A total of 73 summary reports of fatal medical accidents were reviewed. These reports had been submitted by healthcare organisations across Japan to the Japan Medical Safety Research Organization between April 2010 and March 2013. The cause of death in fatal medical accidents, categorised into technical skills, non-technical skills and inevitable progress of disease were evaluated. Non-technical skills were further subdivided into situation awareness, decision making, communication, team working, leadership, managing stress and coping with fatigue. Overall, the cause of death was identified as non-technical skills in 34 cases (46.6%), disease progression in 33 cases (45.2%) and technical skills in two cases (5.5%). In two cases, no consensual determination could be achieved. Further categorisation of cases of non-technical skills were identified as 14 cases (41.2%) of problems with situation awareness, eight (23.5%) with team working and three (8.8%) with decision making. These three subcategories, or combinations of them, were identified as the cause of death in 33 cases (97.1%). Poor non-technical skills were considered to be a significant cause of adverse events in nearly half of the fatal medical accidents examined. Improving non-technical skills may be effective for reducing accidents, and training in particular subcategories of non-technical skills may be especially relevant. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

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).

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.

Next Generation Attenuation Relationships for the Eastern United States (NGA-East)

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

Mahin, Stephen; Bozorgnia, Yousef

2016-04-11

This is a progress report to DOE for project Next Generation Attenuation for Central & Eastern US (NGA-East).This progress report consists of numerous monthly progress segments starting June 1, 2010 until December 31, 2015. Please note: the December 2015 progress report was issued in January 2016 due to the final university financial reporting at the end of this project. For each month, there is a technical progress list, and an update on the financial progress of the project. As you know, this project is jointly funded by the DOE, US Nuclear Regulatory Commission (NRC) and Electric Power Research Institute (EPRI).more » Thus, each segment includes financial progress for these three funding agencies.« less

Technical Feasibility Aspects of the Geothermal Resource Reporting Methodology (GRRM)

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

Badgett, Alex; Young, Katherine R; Dobson, Patrick F.

This paper reviews the technical assessment of the Geothermal Research Reporting Methodology (GRRM, http://en.openei.org/wiki/GRRM) being developed for reporting geothermal resources and project progress. The goal of the methodology is to provide the U.S. Department of Energy's Geothermal Technologies Office (GTO) with a consistent and comprehensible means of evaluating the impacts of its funding programs. The GRRM is designed to provide uniform assessment criteria for geothermal resource grades and developmental phases of geothermal resource exploration and development. This resource grade system provides information on twelve attributes of geothermal resource locations (e.g., temperature, permeability, land access) to indicate potential for geothermal development.more » The GTO plans to use these Protocols to help quantitatively identify the greatest barriers to geothermal development, develop measureable program goals that will have the greatest impact to geothermal deployment, objectively evaluate proposals based (in part) on a project's ability to contribute to program goals, monitor project progress, and report on GTO portfolio performance. The GRRM assesses three areas of geothermal potential: geological, socio-economic, and technical. Previous work and publications have discussed the work done on the geological aspects of this methodology (Young et al. 2015c); this paper details the development of the technical assessment of the GRRM. Technical development attributes considered include: reservoir management, drilling, logistics, and power conversion.« less

Systemic Problems: A perspective on stem cell aging and rejuvenation.

PubMed

Conboy, Irina M; Conboy, Michael J; Rebo, Justin

2015-10-01

This review provides balanced analysis of the advances in systemic regulation of young and old tissue stem cells and suggests strategies for accelerating development of therapies to broadly combat age-related tissue degenerative pathologies. Many highlighted recent reports on systemic tissue rejuvenation combine parabiosis with a "silver bullet" putatively responsible for the positive effects. Attempts to unify these papers reflect the excitement about this experimental approach and add value in reproducing previous work. At the same time, defined molecular approaches, which are "beyond parabiosis" for the rejuvenation of multiple old organs represent progress toward attenuating or even reversing human tissue aging.

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.

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.

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.

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.

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.

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.

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.

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

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

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

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.

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

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.

Preliminary Investigations of the Application of the Early Communication Indicator (ECI) for Infants and Toddlers

ERIC Educational Resources Information Center

Greenwood, Charles R.; Carta, Judith J.; Walker, Dale; Hughes, Kere; Weathers, Mary

2006-01-01

Early interventionists are accountable for the progress of children receiving their services. Technically adequate measures of the progress of individual children are needed. While the Early Communication Indicator (ECI) for infants and toddlers is one such measure, data to support its use are limited to a single research report. In this…

Curriculum-Based Measurement in Science Learning: Vocabulary-Matching as an Indicator of Performance and Progress

ERIC Educational Resources Information Center

Espin, Christine A.; Busch, Todd W.; Lembke, Erica S.; Hampton, David D.; Seo, Kyounghee; Zukowski, Beth A.

2013-01-01

The technical adequacy of curriculum-based measures in the form of short and simple vocabulary-matching probes to predict students' performance and progress in science at the secondary level was investigated. Participants were 198 seventh-grade students from 10 science classrooms. Curriculum-based measurements (CBM) were 5-min vocabulary-matching…

Technical Adequacy of Early Numeracy Curriculum-Based Progress Monitoring Measures for Kindergarten and First-Grade Students

ERIC Educational Resources Information Center

Hampton, David D.; Lembke, Erica S.; Lee, Young-Sun; Pappas, Sandra; Chiong, Cynthia; Ginsburg, Herbert P.

2012-01-01

The purpose of this study was to examine six early numeracy measures used to monitor the mathematics progress of kindergarten and first-grade students. Seventy-one kindergarten students and 75 first-grade students were administered the measures each week. Delayed-alternate form reliability was adequate for instructional decision making on some…

Jet Crackle

DTIC Science & Technology

2015-06-23

DISTRIBUTION/AVAILABILITY STATEMENT DISTRIBUTION A 13. SUPPLEMENTARY NOTES 14. ABSTRACT Fighter jets and other aircraft with high specific thrust engines...interim, memorandum, master’s thesis , progress, quarterly, research, special, group study, etc. 3. DATES COVERED. Indicate the time during which the...State the type of report, such as final, technical, interim, memorandum, master’s thesis , progress, quarterly, research, special, group study, etc

Reading Achievement in Disadvantaged Children as a Consequence of Non Verbal Perceptual Training. Final Technical Progress Report.

ERIC Educational Resources Information Center

Elkind, David; Deblinger, Jo Ann

The theoretical orientation based on perceptual development, proposed by Piaget in 1961, is the starting point of this investigation. According to Piaget, the perception of the young child is "centered" on dominant aspects of the field. With maturity, perception becomes "decentered" and progressively freed from the field. The…

Curriculum-Based Measurement of Reading Progress Monitoring: The Importance of Growth Magnitude and Goal Setting in Decision Making

ERIC Educational Resources Information Center

Van Norman, Ethan R.; Christ, Theodore J.; Newell, Kirsten W.

2017-01-01

Research regarding the technical adequacy of growth estimates from curriculum-based measurement of reading progress monitoring data suggests that current decision-making frameworks are likely to yield inaccurate recommendations unless data are collected for extensive periods of time. Instances where data may not need to be collected for long…

Monitoring Student Progress and Publicising the Results. Information Bank Number 1270.

ERIC Educational Resources Information Center

Jones, D. T. L.

Arguing that assessments of student progress describe the consequences of the interaction of the multitude of elements that make up the educational system, this paper examines the three-tiered assessment system used at Redhill Technical College (RTC), in Surrey, England, to fulfill diagnostic and motivational functions for the college as a whole.…

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.)

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...

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.

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.

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.

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.

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.

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.

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.

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 ...

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.

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.

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.

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.

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

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.

Magnetic Earth Ionosphere Resonant Frequencies

NASA Technical Reports Server (NTRS)

Spaniol, Craig

1994-01-01

The Community College Division is pleased to report progress of NASA funded research at West Virginia State College. During this reporting period, the project research group has continued with activities to develop instrumentation capability designed to monitor resonant cavity frequencies in the atmospheric region between the Earth's surface and the ionosphere. In addition, the project's principal investigator, Dr. Craig Spaniol, and NASA technical officer, Dr. John Sutton, have written and published technical papers intended to expand the scientific and technical framework needed for project research. This research continues to provide an excellent example of government and education working together to provide significant research in the college environment. This cooperative effort has provided many students with technical project work which compliments their education.

48 CFR 742.1170-1 - General.

Code of Federal Regulations, 2013 CFR

2013-10-01

... MANAGEMENT CONTRACT ADMINISTRATION Production, Surveillance, and Reporting 742.1170-1 General. Performance... cognizant technical officer, to maintain adequate knowledge of the contractor's activities and progress in...

48 CFR 742.1170-1 - General.

Code of Federal Regulations, 2012 CFR

2012-10-01

... MANAGEMENT CONTRACT ADMINISTRATION Production, Surveillance, and Reporting 742.1170-1 General. Performance... cognizant technical officer, to maintain adequate knowledge of the contractor's activities and progress in...

48 CFR 742.1170-1 - General.

Code of Federal Regulations, 2014 CFR

2014-10-01

... MANAGEMENT CONTRACT ADMINISTRATION Production, Surveillance, and Reporting 742.1170-1 General. Performance... cognizant technical officer, to maintain adequate knowledge of the contractor's activities and progress in...

48 CFR 742.1170-1 - General.

Code of Federal Regulations, 2010 CFR

2010-10-01

... MANAGEMENT CONTRACT ADMINISTRATION Production, Surveillance, and Reporting 742.1170-1 General. Performance... cognizant technical officer, to maintain adequate knowledge of the contractor's activities and progress in...

Access and Success for System Goals for People of Color in Washington Community and Technical Colleges: Progress Report. Research Report No. 05-3

ERIC Educational Resources Information Center

Washington State Board for Community and Technical Colleges, 2005

2005-01-01

This report is designed to provide information for readers, promote discussion, and set the stage for future initiatives to address outcomes for people of color. The data provided speaks to the success that Washington's community and technical colleges have achieved in increasing higher education access and participation for students of color. It…

Internal Consistency of General Outcome Measures in Grades 1-8. Technical Report # 0915

ERIC Educational Resources Information Center

Anderson, Daniel; Tindal, Gerald; Alonzo, Julie

2009-01-01

We developed alternate forms of a math test for use in both screening students at risk of failure and monitoring their progress over time. In this technical report, we present results of the screener, used in the fall of 2009. The 48-item test was aligned to the National Council of Teachers of Mathematics (NCTM) Curriculum Focal Point Standards…

Career and Technical Education: States Aligning Programs to Meet Workforce Needs. The Progress of Education Reform. Volume 15, Number 2

ERIC Educational Resources Information Center

Zinth, Jennifer Dounay

2014-01-01

Across the 50 states, career and technical education (CTE) programs at the K-12 and postsecondary levels have seen enormous policy action - 2013 alone saw at least 78 substantive policy changes via legislation, state board rules and executive orders specific to CTE and workforce development. What are the drivers behind this sudden policymaker…

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...

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...

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...

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...

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...

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

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.

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.

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.

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.

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.

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.