scholarly journals Bimetallic Nanoparticles as a Model System for an Industrial NiMo Catalyst

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3727
Author(s):  
Sara Blomberg ◽  
Niclas Johansson ◽  
Esko Kokkonen ◽  
Jenny Rissler ◽  
Linnéa Kollberg ◽  
...  
Keyword(s):  
Bimetallic Nanoparticles ◽  
Model System ◽  
Native Oxide ◽  
Oxide Shell ◽  
Industrial System ◽  
Narrow Size Distribution ◽  
Nimo Catalysts ◽  
Further Development ◽  
Industrial Relevance

An in-depth understanding of the reaction mechanism is required for the further development of Mo-based catalysts for biobased feedstocks. However, fundamental studies of industrial catalysts are challenging, and simplified systems are often used without direct comparison to their industrial counterparts. Here, we report on size-selected bimetallic NiMo nanoparticles as a candidate for a model catalyst that is directly compared to the industrial system to evaluate their industrial relevance. Both the nanoparticles and industrial supported NiMo catalysts were characterized using surface- and bulk-sensitive techniques. We found that the active Ni and Mo metals in the industrial catalyst are well dispersed and well mixed on the support, and that the interaction between Ni and Mo promotes the reduction of the Mo oxide. We successfully produced 25 nm NiMo alloyed nanoparticles with a narrow size distribution. Characterization of the nanoparticles showed that they have a metallic core with a native oxide shell with a high potential for use as a model system for fundamental studies of hydrotreating catalysts for biobased feedstocks.

TEM characterization of silicon epitaxial layer grown on Si-TaS2, eutectic composites

1991 ◽  
Vol 49 ◽  
pp. 802-803
Author(s):  
C.M. Sung ◽  
M. Levinson ◽  
M. Tabasky ◽  
K. Ostreicher ◽  
B.M. Ditchek
Keyword(s):  
Substrate Surface ◽  
Bulk Sample ◽  
Surface Cleaning ◽  
Native Oxide ◽  
Czochralski Growth ◽  
Ion Milling ◽  
Cross Sectional ◽  
Cleaning Methods ◽  
Field Emission Cathodes

Directionally solidified Si/TaSi2 eutectic composites for the development of electronic devices (e.g. photodiodes and field-emission cathodes) were made using a Czochralski growth technique. High quality epitaxial growth of silicon on the eutectic composite substrates requires a clean silicon substrate surface prior to the growth process. Hence a preepitaxial surface cleaning step is highly desirable. The purpose of this paper is to investigate the effect of surface cleaning methods on the epilayer/substrate interface and the characterization of silicon epilayers grown on Si/TaSi2 substrates by TEM.Wafers were cut normal to the <111> growth axis of the silicon matrix from an approximately 1 cm diameter Si/TaSi2 composite boule. Four pre-treatments were employed to remove native oxide and other contaminants: 1) No treatment, 2) HF only; 3) HC1 only; and 4) both HF and HCl. The cross-sectional specimens for TEM study were prepared by cutting the bulk sample into sheets perpendicular to the TaSi2 fiber axes. The material was then prepared in the usual manner to produce samples having a thickness of 10μm. The final step was ion milling in Ar+ until breakthrough occurred. The TEM samples were then analyzed at 120 keV using the Philips EM400T.

Synthesis of Bimetallic AuPt Nanoparticles in Aqueous Solution and Electrocatalytic Activity

2005 ◽  
Vol 900 ◽  
Author(s):  
Peter N. Njoki ◽  
Jin Luo ◽  
Aisley Jacob ◽  
Rizwan Munawar ◽  
Bilal Khan ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Electrocatalytic Activity ◽  
Bimetallic Nanoparticles ◽  
Rotating Disk ◽  
Reduction Reaction ◽  
Rotating Disk Electrode ◽  
Morphological Properties ◽  
Nanoparticle Catalysts ◽  
Bimetallic Nanoparticle

ABSTRACTThe ability to control composition and size in the synthesis of bimetallic nanoparticles is important for the exploitation of the bimetallic catalytic properties. This paper reports recent findings of an investigation of the synthesis of gold-platinum (AuPt) bimetallic nanoparticles in aqueous solution via reduction of AuCl4− and PtCl42− using a combination of reducing and capping agents. In addition to characterization of the morphological properties of the AuPt nanoparticles using TEM and XRD, the electrocatalytic activity of the carbon-supported AuPt nanoparticle catalysts was also examined for oxygen reduction reaction (ORR) using the rotating disk electrode (RDE) technique. The findings have implications to the design of bimetallic nanoparticle catalysts for fuel cell reactions.

scholarly journals Characterization of a Murine Model System to Study MicroRNA-147 During Inflammatory Organ Injury

Inflammation ◽  
2021 ◽  
Author(s):  
Boyun Kim ◽  
Victor Guaregua ◽  
Xuebo Chen ◽  
Chad Zhao ◽  
Wanyi Yeow ◽  
...  
Keyword(s):  
Murine Model ◽  
Model System ◽  
Organ Injury

scholarly journals Drosophila Heart as a Model for Cardiac Development and Diseases

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3078
Author(s):  
Anissa Souidi ◽  
Krzysztof Jagla
Keyword(s):  
Cardiac Dysfunction ◽  
Congenital Heart ◽  
Cardiac Development ◽  
Heart Diseases ◽  
Heart Defects ◽  
Fruit Fly ◽  
Model System ◽  
Fast Imaging

The Drosophila heart, also referred to as the dorsal vessel, pumps the insect blood, the hemolymph. The bilateral heart primordia develop from the most dorsally located mesodermal cells, migrate coordinately, and fuse to form the cardiac tube. Though much simpler, the fruit fly heart displays several developmental and functional similarities to the vertebrate heart and, as we discuss here, represents an attractive model system for dissecting mechanisms of cardiac aging and heart failure and identifying genes causing congenital heart diseases. Fast imaging technologies allow for the characterization of heartbeat parameters in the adult fly and there is growing evidence that cardiac dysfunction in human diseases could be reproduced and analyzed in Drosophila, as discussed here for heart defects associated with the myotonic dystrophy type 1. Overall, the power of genetics and unsuspected conservation of genes and pathways puts Drosophila at the heart of fundamental and applied cardiac research.

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.

Characterization of native oxide film on amorphous Co66Si16B12Fe4Mo2 by X-ray photoelectron spectroscopy

2010 ◽  
Vol 490 (1-2) ◽  
pp. 613-617 ◽  
Author(s):  
Rohit Jain ◽  
Deepika Bhandari ◽  
Anil Dhawan ◽  
S.K. Sharma
Keyword(s):  
Oxide Film ◽  
Photoelectron Spectroscopy ◽  
Native Oxide ◽  
X Ray

A new model system for endometritis: Basic concepts and characterization of phenotypic and functional properties of bovine uterine neutrophils

1996 ◽  
Vol 46 (8) ◽  
pp. 1339-1356 ◽  
Author(s):  
H. Zerbe ◽  
H.-J. Schuberth ◽  
M. Hoedemaker ◽  
E. Grunert ◽  
W. Leibold
Keyword(s):  
Functional Properties ◽  
Model System ◽  
New Model ◽  
Basic Concepts
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