scholarly journals Long-Term Stable Structures Formed by Ion-Beam Modification of Silver Film for SERS Applications

2021 ◽  
Vol 2015 (1) ◽  
pp. 012099
Author(s):  
S. M. Novikov ◽  
O. A. Streletskiy ◽  
N.V. Doroshina ◽  
D. I. Yakubovsky ◽  
M. S. Mironov ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Silver Film ◽  
Amplification Factor ◽  
Ion Beam ◽  
Ambient Atmosphere ◽  
Nanostructured Surfaces ◽  
Ion Beam Modification ◽  
Silver Nps ◽  
Stable Structures

Abstract Ensembles of silver nanoparticles (NPs) with size ~45 nm formed from the silver film using an ion beam modification are studied. The optical spectroscopy demonstrated that the fabricated ensembles of silver NPs keep stable their plasmonic properties in an ambient atmosphere for at least 39 days due to their monocrystalline nature. We use the scanning Raman microscope to map the SERS from Crystal Violet homogeneously adsorbed on these ensembles. It was found that the manufactured ensembles have a strong amplification factor, and this factor is preserved for these ensembles even after more than one month of storage in the surrounding atmosphere. Hereby, by ion beam modification of silver film, it is possible to fabricate the NPs with stable plasmonic properties and form nanostructured surfaces to be applied in sensor technologies and SERS.

scholarly journals Developmental Exposure to Silver Nanoparticles Leads to Long Term Gut Dysbiosis and Neurobehavioral Alterations

2020 ◽  
Author(s):  
Zhen Lyu ◽  
Shreya Ghoshdastidar ◽  
Karamkolly Rekha ◽  
Dhananjay Suresh ◽  
Jiude Mao ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Body Fat ◽  
Repetitive Behaviors ◽  
Developmental Exposure ◽  
Male And Female ◽  
Female Mice ◽  
Gut Dysbiosis ◽  
Study Results ◽  
Silver Nps

Abstract Due to their antimicrobial properties, silver nanoparticles (NPs) are used in a wide range of consumer products that includes topical wound dressings, coatings for biomedical devices, and food-packaging to extend the shelf-life. Despite their beneficial antimicrobial effects, developmental exposure to such NPs may lead to gut dysbiosis and long-term health consequences in exposed offspring. Silver NPs can cross the placenta and blood-brain-barrier to translocate in the brain of offspring. The underlying hypothesis tested in the current study was that developmental exposure of male and female mice to silver NPs disrupts the microbiome-gut-brain axis. To examine for such effects, C57BL6 female mice were exposed orally to silver NPs at a dose of 3 mg/kg BW or vehicle control two weeks prior to breeding and throughout gestation. Male and female offspring were tested in various mazes that measure different behavioral domains, and the gut microbial profiles were surveyed from 30 through 120 days of age. Our study results suggest that developmental exposure results in increased likelihood of engaging in repetitive behaviors and reductions in resident microglial cells. Echo-MRI results indicate increased body fat in offspring exposed to NP exhibit. Coprobacillus spp., Mucispirillum spp., and Bifidobacterium spp. were reduced, while Prevotella spp., Bacillus spp., Planococcaceae, Staphylococcus spp., Enterococcus spp., and Ruminococcus spp. were increased in those developmentally exposed to NPs. These bacterial changes were linked to behavioral and metabolic alterations. In conclusion, developmental exposure of silver NPs results in long term gut dysbiosis, body fat increase and neurobehavioral alterations in offspring.

Fluorocarbon Precursor for High Aspect Ratio via Milling in Focused Ion Beam Modification of Integrated Circuits

2004 ◽  
Author(s):  
Valery Ray
Keyword(s):  
Side Effects ◽  
Aspect Ratio ◽  
Integrated Circuits ◽  
High Aspect Ratio ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Enabling Technology ◽  
Si Substrate ◽  
Ion Beam Modification ◽  
The Past

Abstract Gas Assisted Etching (GAE) is the enabling technology for High Aspect Ratio (HAR) circuit access via milling in Focused Ion Beam (FIB) circuit modification. Metal interconnect layers of microelectronic Integrated Circuits (ICs) are separated by Inter-Layer Dielectric (ILD) materials, therefore HAR vias are typically milled in dielectrics. Most of the etching precursor gases presently available for GAE of dielectrics on commercial FIB systems, such as XeF2, Cl2, etc., are also effective etch enhancers for either Si, or/and some of the metals used in ICs. Therefore use of these precursors for via milling in dielectrics may lead to unwanted side effects, especially in a backside circuit edit approach. Making contacts to the polysilicon lines with traditional GAE precursors could also be difficult, if not impossible. Some of these precursors have a tendency to produce isotropic vias, especially in Si. It has been proposed in the past to use fluorocarbon gases as precursors for the FIB milling of dielectrics. Preliminary experimental evaluation of Trifluoroacetic (Perfluoroacetic) Acid (TFA, CF3COOH) as a possible etching precursor for the HAR via milling in the application to FIB modification of ICs demonstrated that highly enhanced anisotropic milling of SiO2 in HAR vias is possible. A via with 9:1 aspect ratio was milled with accurate endpoint on Si and without apparent damage to the underlying Si substrate.

Green and Simple Synthesis of Silver Nanoparticles by Aqueous Extract of Perovskia abrotanoides: Characterization, Optimization and Antimicrobial Activity

2020 ◽  
Vol 21 (11) ◽  
pp. 1129-1137 ◽  
Author(s):  
Somayeh Mirsadeghi ◽  
Masoumeh F. Koudehi ◽  
Hamid R. Rajabi ◽  
Seied M. Pourmortazavi
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Minimum Inhibitory Concentration ◽  
Plant Extract ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
Extraction Temperature ◽  
Silver Particles ◽  
Silver Nps ◽  
Perovskia Abrotanoides

Background: Herein, we report the biosynthesis procedure to prepare silver nanoparticles as reduction and capping agents with the aqueous plant extract of Perovskia abrotanoides. Methods: The therapeutic application of silver nanoparticles entirely depends on the size and shape of the nanoparticles therefore, their control during the synthesis procedure is so important. The effects of synthesis factors, for example, silver ion concentration, the mass of plant extract, reaction time and extraction temperature, on the size of silver particles were considered and optimized. Several analytical methods were used for the characterization of silver NPs including FT-IR and UV–Vis spectrophotometer, XRD and SEM. Results: The results showed that the mean size of the silver particles was about 51 nm. Moreover, the antibacterial properties of biosynthesized silver NPs were investigated by the minimum inhibitory concentration, minimum bactericidal concentration, and Well-diffusion tests. The minimum inhibitory concentration/ minimum bactericidal concentration values of silver NPs and aqueous plant extract versus Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus) and Gram-negative bacteria (E. coli) were 3.03/0.00, 1.20/0.01, 3.06/0.00, 0.98/1.04, 1.00/0.05 and 1.30/0.03 (mg/mL), respectively. Conclusion: The antimicrobial activity study displayed that the synthesized silver nanoparticles by plant extract have better antimicrobial properties compared to aqueous plant extract of Perovskia abrotanoides.

Ion beam-treated space polymers: long-term stability in GEO-simulated environments

2021 ◽  
Author(s):  
Jacob Kleiman ◽  
Zelina Iskanderova ◽  
Leonid Krishtein ◽  
J. R. Dennison ◽  
Brian Wood ◽  
...  
Keyword(s):  
Ion Beam ◽  
Term Stability ◽  
Long Term Stability ◽  
Simulated Environments

scholarly journals Microstructure Evolution in a Solid Oxide Fuel Cell Stack Quantified with Interfacial Free Energy

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3476
Author(s):  
Tomasz A. Prokop ◽  
Grzegorz Brus ◽  
Janusz S. Szmyd
Keyword(s):  
Free Energy ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Microstructure Evolution ◽  
Ion Beam ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Long Term Performance ◽  
Term Performance

Degradation of electrode microstructure is one of the key factors affecting long term performance of Solid Oxide Fuel Cell systems. Evolution of a multiphase system can be described quantitatively by the change in its interfacial energy. In this paper, we discuss free energy of a microstructure to showcase the anisotropy of its evolution during a long-term performance experiment involving an SOFC stack. Ginzburg Landau type functional is used to compute the free energy, using diffuse phase distributions based on Focused Ion Beam Scanning Electron Microscopy images of samples taken from nine different sites within the stack. It is shown that the rate of microstructure evolution differs depending on the position within the stack, similar to phase anisotropy. However, the computed spatial relation does not correlate with the observed distribution of temperature.

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