scholarly journals Erratum: Corrigendum: Efficient design, accurate fabrication and effective characterization of plasmonic quasicrystalline arrays of nano-spherical particles

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Farhad A. Namin ◽  
Yu A. Yuwen ◽  
Liu Liu ◽  
Anastasios H. Panaretos ◽  
Douglas H. Werner ◽  
...  
Keyword(s):  
Spherical Particles ◽  
Efficient Design

scholarly journals Efficient design, accurate fabrication and effective characterization of plasmonic quasicrystalline arrays of nano-spherical particles

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Farhad A. Namin ◽  
Yu A. Yuwen ◽  
Liu Liu ◽  
Anastasios H. Panaretos ◽  
Douglas H. Werner ◽  
...  
Keyword(s):  
Periodic Structures ◽  
Mie Theory ◽  
Quantitative Model ◽  
Spherical Particles ◽  
Two Dimensional ◽  
Efficient Design ◽  
Spherical Nanoparticles ◽  
Quantitative Results ◽  
Spherical Arrays

Abstract In this paper, the scattering properties of two-dimensional quasicrystalline plasmonic lattices are investigated. We combine a newly developed synthesis technique, which allows for accurate fabrication of spherical nanoparticles, with a recently published variation of generalized multiparticle Mie theory to develop the first quantitative model for plasmonic nano-spherical arrays based on quasicrystalline morphologies. In particular, we study the scattering properties of Penrose and Ammann- Beenker gold spherical nanoparticle array lattices. We demonstrate that by using quasicrystalline lattices, one can obtain multi-band or broadband plasmonic resonances which are not possible in periodic structures. Unlike previously published works, our technique provides quantitative results which show excellent agreement with experimental measurements.

scholarly journals Deep Learning Based Instance Segmentation of Titanium Dioxide Particles in the Form of Agglomerates in Scanning Electron Microscopy

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 968
Author(s):  
Paul Monchot ◽  
Loïc Coquelin ◽  
Khaled Guerroudj ◽  
Nicolas Feltin ◽  
Alexandra Delvallée ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Titanium Dioxide ◽  
Learning Community ◽  
Spherical Particles ◽  
Average Value ◽  
Size Characterization ◽  
Scanning Electron

The size characterization of particles present in the form of agglomerates in images measured by scanning electron microscopy (SEM) requires a powerful image segmentation tool in order to properly define the boundaries of each particle. In this work, we propose to use an algorithm from the deep statistical learning community, the Mask-RCNN, coupled with transfer learning to overcome the problem of generalization of the commonly used image processing methods such as watershed or active contour. Indeed, the adjustment of the parameters of these algorithms is almost systematically necessary and slows down the automation of the processing chain. The Mask-RCNN is adapted here to the case study and we present results obtained on titanium dioxide samples (non-spherical particles) with a level of performance evaluated by different metrics such as the DICE coefficient, which reaches an average value of 0.95 on the test images.

Preparation and characterization of uniform submicrometer metal niobate particles: Part II. Magnesium niobate and potassium niobate

1992 ◽  
Vol 7 (4) ◽  
pp. 912-918 ◽  
Author(s):  
Myung Jin Kim ◽  
Egon Matijević
Keyword(s):  
Colloidal Particles ◽  
Spherical Particles ◽  
Potassium Niobate ◽  
Homogeneous Precipitation ◽  
Potassium Salts ◽  
Chemical Mechanisms ◽  
Magnesium Niobate

Amorphous spherical particles of magnesium and potassium niobates were produced by homogeneous precipitation in solutions of magnesium and potassium salts, respectively, in the presence of polymeric niobium oxo-hydroxide ions. At pH 9 solids of definitive compositions were achieved and converted to crystalline powders of MgNb2O6 and KNbO3 on calcination. Chemical mechanisms for the formation and transformation of such colloidal particles are offered.

scholarly journals Application of Dynamic and Static Light Scattering for Size and Shape Characterization of Small Extracellular Nanoparticles in Plasma and Ascites of Ovarian Cancer Patients

2021 ◽  
Vol 22 (23) ◽  
pp. 12946
Author(s):  
Ksenija Kogej ◽  
Darja Božič ◽  
Borut Kobal ◽  
Maruša Herzog ◽  
Katarina Černe
Keyword(s):  
Ovarian Cancer ◽  
Light Scattering ◽  
Spherical Particles ◽  
Radius Of Gyration ◽  
Non Invasive ◽  
Peritoneal Washing ◽  
Angular Dependency ◽  
Shape Characterization ◽  
Further Development

In parallel to medical treatment of ovarian cancer, methods for the early detection of cancer tumors are being sought. In this contribution, the use of non-invasive static (SLS) and dynamic light scattering (DLS) for the characterization of extracellular nanoparticles (ENPs) in body fluids of advanced serous ovarian cancer (OC) and benign gynecological pathology (BP) patients is demonstrated and critically evaluated. Samples of plasma and ascites (OC patients) or plasma, peritoneal fluid, and peritoneal washing (BP patients) were analyzed. The hydrodynamic radius (Rh) and the radius of gyration (Rg) of ENPs were calculated from the angular dependency of LS intensity for two ENP subpopulations. Rh and Rg of the predominant ENP population of OC patients were in the range 20–30 nm (diameter 40–60 nm). In thawed samples, larger particles (Rh mostly above 100 nm) were detected as well. The shape parameter ρ of both particle populations was around 1, which is typical for spherical particles with mass concentrated on the rim, as in vesicles. The Rh and Rg of ENPs in BP patients were larger than in OC patients, with ρ ≈ 1.1–2, implying a more elongated/distorted shape. These results show that SLS and DLS are promising methods for the analysis of morphological features of ENPs and have the potential to discriminate between OC and BP patients. However, further development of the methodology is required.

scholarly journals The Synthesis and Effect of Silver Nanoparticles on the Adsorption of Cu2+ from Aqueous Solutions

2020 ◽  
Vol 10 (14) ◽  
pp. 4840
Author(s):  
Ghadah M. Al-Senani ◽  
Nada Al-Kadhi
Keyword(s):  
Aqueous Solution ◽  
Freundlich Isotherm ◽  
Spherical Particles ◽  
Convolvulus Arvensis ◽  
X Ray ◽  
Nanoparticle Surface ◽  
Before And After ◽  
Adsorption Processes ◽  
Sem Analyses

The adsorption of Cu2+ ions from an aqueous solution using AgNPs synthesized from Convolvulus arvensis leaf extract was investigated. The characterization of AgNPs was investigated before and after the adsorption of Cu2+ ions via Fourier-transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDS), and scanning electron microscopy (SEM) analyses. The adsorbent contained various functional groups in addition to the AgNPs, which contributed to the Cu2+ ions adsorption. The silver nanoparticle surface consisted of spherical particles and deep pores, which adsorbed numerous Cu2+ ions. The influences of dosage, pH, and contact time on adsorption of 10 and 50 mg/L Cu2+ at 298 K, and initial Cu2+ concentrations at 298 and 323 K were studied. It was found that the highest percentage of Cu2+ ions adsorbed from an aqueous solution was 98.99%; the aqueous solution had 10 mg/L of Cu2+ ions and 0.2 g of AgNPs, at pH 12 and 298 K. A pseudo-second kinetics model offered the most accurate description of the process of adsorption. The process of Cu2+ adsorption more resembled a Langmuir rather than a Freundlich isotherm model, including chemical and physical mixed adsorption (mixed adsorption) processes, and was exothermic and spontaneous.

Preparation and characterization of sub-micron spherical particles of Al2O3, SiO2 and mullite

1998 ◽  
Vol 53 (3) ◽  
pp. 247-251 ◽  
Author(s):  
P. Murugavel ◽  
M. Kalaiselvam ◽  
M.K. Renganathan ◽  
A.R. Raju
Keyword(s):  
Spherical Particles

scholarly journals SIMULATION OF THE POLY- AND MONODISPERSED GRANULAR MATERIAL. PART II: THE STABILITY STATE CHARACTERIZATION / DAUGIADISPERSIO IR VIENDISPERSIO DALELIŲ MIŠINIO ELGSENOS TYRIMAS. II DALIS: STABILUMO BŪSENŲ CHARAKTERIZAVIMAS

2012 ◽  
Vol 4 (2) ◽  
pp. 59-66 ◽  
Author(s):  
Gvidas Pocius ◽  
Robertas Balevičius
Keyword(s):  
Volume Fraction ◽  
Particle Surface ◽  
Spherical Particles ◽  
Time Step ◽  
Resonant Effect ◽  
The Stability ◽  
Gravity Acceleration ◽  
Granular Aggregate ◽  
Radius Size

In the Part I of the paper, structure of granular aggregates obtained after compaction of poly- and mono-dispersed spherical particles was characterized in terms of the coordination number, particles contacting forces and volume fraction distributions. This part of investigation deals with characterization of the state of stability under quasistatic conditions of the formed granular aggregate structure. The proposed method is based on visualization of the plane of the particle radius size plotted normally to the particle velocity vector. At the beginning of the compacting process, when the discrete particle drops down under the gravity acceleration (almost free of contact with other particles), the planes plotted the cylinder-like pattern at each time step. At the quasistatic state, when the acceleration of the settled particles tends to negligible values, the plot of these planes represents a certain texture appearing on the particle surface. For the interpretation of these textures, Shilnikov's homoclinic bifurcation theory was discussed and applied. In particular, it was found that textures specifying the quasistatic state mainly resulted from the resonant effect depending on the degree of freedom of the analyzed particles. Santrauka Šioje straipsnio dalyje pagrindinis dėmesys skiriamas viendispersinio ir daugiadispersio sferinių dalelių mišinio mikrobūsenai charakterizuoti, analizuojant atskirų mišinio dalelių stabilumą esant kvazistatiniam būviui. Tiriamos ir vizualizuojamos atskirų dalelių greičio vektorių normalinių plokštumų formuojamos tekstūros, kurios esant kvazistatiniam būviui interpretuojamos kaip tam tikri rezonansinio poveikio dariniai, gaubiantys dalelių paviršių.

scholarly journals Numerical Modeling for Engineering Analysis and Designing of Optimum Support Systems for Headrace Tunnel

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Sajjad Hussain ◽  
Zahid Ur Rehman ◽  
Noor Mohammad ◽  
Muhammad Tahir ◽  
Khan Shahzada ◽  
...  
Keyword(s):  
Rock Mass ◽  
Support Systems ◽  
Research Work ◽  
Strength Properties ◽  
Efficient Design ◽  
Headrace Tunnel ◽  
And Performance ◽  
Selection Of

The empirical and numerical design approaches are considered very important in the viable and efficient design of support systems, stability analysis for tunnel, and underground excavations. In the present research work, the rock mass rating (RMR) and tunneling quality index (Q-system) were used as empirical methods for characterization of rock mass based on real-time geological and site geotechnical data and physical and strength properties of rock samples collected from the alignment of tunnel. The rock mass along the tunnel axis was classified into three geotechnical units (GU-1, GU-2, and GU-3). The support systems for each geotechnical unit were designed. The 2D elastoplastic finite-element method (FEM) was used for the analysis of rock mass behavior, in situ and redistribution stresses, plastic thickness around the tunnel, and performance of the design supports for the selection of optimum support system among RMR and Q supports for each geotechnical unit of tunnel. Based on results, Q support systems were found more effective for GU-1 and GU-2 as compared to RMR support systems and RMR support systems for GU-3 as compared to Q support systems.

Preparation and Characterization of A Composite Obtained through Ti (IV) and Phosphoric Acid

2014 ◽  
Vol 775-776 ◽  
pp. 97-101
Author(s):  
Loanda Raquel Cumba ◽  
U.O. Bicalho ◽  
D.R. Carmo
Keyword(s):  
Phosphoric Acid ◽  
Titanium Isopropoxide ◽  
Deionized Water ◽  
Spherical Particles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electron Microscopies ◽  
Prepared Material ◽  
Scanning Electron

This paper describes the preparation and complementary characterization of a composite formed from the activation of titanium isopropoxide by phosphoric acid and deionized water (TiP).Techniques such as, X-ray diffraction (XRD), Raman , electronic (UV-vis) and Scanning electron microscopies (SEM) were used for characterization of this new composite formed. In the X-ray diffractogram of TIP was observed four intense peaks. A strong absorption was observed in the region 362-445 nm. The scanning electron microscopy of TiP, shows that the prepared material consists mostly of a cluster of spherical particles with diameters ranging from 2.35 to 2.60 μm.

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