MEASUREMENT METHODS | Structural and Chemical Properties: Transmission Electron Microscopy

2009 ◽  
pp. 769-789 ◽  
Author(s):  
R. Marassi ◽  
F. Nobili
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chemical Properties ◽  
Measurement Methods ◽  
Transmission Electron ◽  
And Chemical Properties

Structural and Chemical Properties of MBE Grown Niobium Overlayers on (110) Rutile

1996 ◽  
Vol 441 ◽  
Author(s):  
J. Marien ◽  
T. Wagner ◽  
M. Rühle
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Defect Structure ◽  
Chemical Properties ◽  
High Energy ◽  
Initial Growth ◽  
High Energy Electron ◽  
Transmission Electron ◽  
Different Temperatures ◽  
And Chemical Properties

AbstractThin Nb films were grown by MBE in a UHV chamber at two different temperatures (50°C and 950°C) on the (110) surface of TiO2 (rutile).At a growth temperature of 50°C, reflection high energy electron diffraction (RHEED) revealed epitaxial growth of Nb on rutile: (110)[001] TiO2 ¦¦ (100)[001] Nb. In addition, investigations with Auger electron spectroscopy (AES) revealed that a chemical reaction took place between the Nb overlayer and the TiO2 substrate at the initial growth stage. A 2 nm thick reaction layer at the Nb/TiO2 interface has been identified by means of conventional transmission electron microscopy (CTEM) and high-resolution transmission electron microscopy (HRTEM).At a substrate temperature of 950°C, during growth, the Nb film was oxidized completely, and NbO2 grew epitaxially on TiO2. The structure and the chemical composition of the overlayers have been investigated by RHEED, AES, CTEM and HRTEM. Furthermore, it was determined that the reaction of Nb with TiO2 is governed by the defect structure of the TiO2 and the relative oxygen affinities of Nb and TiO2.

Ultrastructural Morphology of two Sensilla Placodea on the Antenna of a Parasitic Wasp

1976 ◽  
Vol 34 ◽  
pp. 190-191
Author(s):  
Margaret R. Barlin
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Parasitic Wasp ◽  
Chemical Properties ◽  
Behavioral Sequence ◽  
Female Antenna ◽  
Egg Deposition ◽  
Transmission Electron ◽  
Egg Case ◽  
And Chemical Properties

Females of the wasp Tetrastichus hagenowii (Hymenoptera: Chalcidoidea) lay their eggs in cockroach egg cases, the young hatch and feed on the cockroach eggs. Prior to egg deposition the parasites follow a complex behavioral sequence, including tapping their antennal tips on the eggcase, thus enabling them to detect various mechanical and chemical properties of the cockroach egg case and determine its suitability for oviposition (unpublished data).Sensory sensilla occur along the entire length of the female antenna (Fig. 1). Two of the more prominent sensilla were studied by scanning and transmission electron microscopy, these are both sensilla placodea (PI and P2 in Figs. 1 and 2) which are chemoreceptors (1). Numerous hair-like sensilla (H) and a few bulb-like sensilla (B) are also present (Figs. 1 and 2). Sensilla placodea occur frequently on hymenopteran antennae (1), but the occurrence of two types on the same insect has not been reported previously.

(Zn,Mn)Te-Based Nanowires for Spintronic Applications: A TEM Study of Structural and Chemical Properties

2010 ◽  
Vol 638-642 ◽  
pp. 2154-2159 ◽  
Author(s):  
Holm Kirmse ◽  
Wolfgang Neumann ◽  
Slawomir Kret ◽  
Elzbieta Janik ◽  
Wojciech Zaleszczyk ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Stacking Faults ◽  
Chemical Properties ◽  
Structural Perfection ◽  
Vapor Liquid Solid ◽  
Cover Layer ◽  
Transmission Electron ◽  
High Structural Perfection ◽  
And Chemical Properties

(Zn,Mn)Te nanowires were grown via vapor-liquid-solid mode as test structures for spintronic applications. The structural and chemical properties of the nanowires were inspected by transmission electron microscopy. The nanowires contain much less stacking faults compared to ZnTe nanowires. This high structural perfection can be attributed to a rough liquid-solid interface as found by high-resolution transmission electron microscopy. The composition of the nanowires and, in particular, the Mn distribution is homogeneous. A ZnO cover layer forms after the growth of the nanowires.

scholarly journals Optimization of Innovative Three-Dimensionally-Structured Hybrid Vesicles to Improve the Cutaneous Delivery of Clotrimazole for the Treatment of Topical Candidiasis

Pharmaceutics ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 263 ◽  
Author(s):  
Maria Letizia Manca ◽  
Iris Usach ◽  
José Esteban Peris ◽  
Antonella Ibba ◽  
Germano Orrù ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chemical Properties ◽  
Chemical Characterization ◽  
Yeast Cells ◽  
Unilamellar Vesicles ◽  
Transmission Electron ◽  
Physico Chemical

New three-dimensionally-structured hybrid phospholipid vesicles, able to load clotrimazole in a high amount (10 mg/mL), were obtained for the first time in this work by significantly reducing the amount of water (≤10%), which was replaced with a mixture of glycerol and ethanol (≈90%). A pre-formulation study was carried out to evaluate the effect of both the composition of the hydrating medium and the concentration of the phospholipid on the physico-chemical properties of hybrid vesicles. Four different three-dimensionally-structured hybrid vesicles were selected as ideal systems for the topical application of clotrimazole. An extensive physico-chemical characterization performed using transmission electron microscopy (TEM), cryogenic transmission electron microscopy (cryo-TEM), 31P-NMR, and small-angle X-ray scattering (SAXS) displayed the formation of small, multi-, and unilamellar vesicles very close to each other, and was capable of forming a three-dimensional network, which stabilized the dispersion. Additionally, the dilution of the dispersion with water reduced the interactions between vesicles, leading to the formation of single unilamellar vesicles. The evaluation of the in vitro percutaneous delivery of clotrimazole showed an improved drug deposition in the skin strata provided by the three-dimensionally-structured vesicles with respect to the commercial cream (Canesten®) used as a reference. Hybrid vesicles were highly biocompatible and showed a significant antifungal activity in vitro, greater than the commercial cream Canesten®. The antimycotic efficacy of formulations was confirmed by the reduced proliferation of the yeast cells at the site of infection in vivo. In light of these results, clotrimazole-loaded, three-dimensionally-structured hybrid vesicles appear to be one of the most innovative and promising formulations for the treatment of candidiasis infections.

A unique pathway of PtNi nanoparticle formation observed with liquid cell transmission electron microscopy

Nanoscale ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 1414-1418
Author(s):  
Liyun Zheng ◽  
Lixin Zhao ◽  
Songhao Zhao ◽  
Xiaowei Zhang ◽  
Karen C. Bustillo ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Chemical Properties ◽  
Controlled Synthesis ◽  
Physical And Chemical Properties ◽  
Nanoparticle Growth ◽  
Transmission Electron ◽  
Liquid Cell ◽  
Physical And Chemical ◽  
Synthesis Of Nanomaterials ◽  
And Chemical Properties

An understanding of nanoparticle growth is significant for controlled synthesis of nanomaterials with desired physical and chemical properties.

Mineralogy of volcanically derived alluvial soils at Moshi, Tanzania

Soil Research ◽  
2016 ◽  
Vol 54 (8) ◽  
pp. 926
Author(s):  
T. S. Taylor ◽  
J. C. Hughes ◽  
L. W. Titshall
Keyword(s):  
Electron Microscopy ◽  
Clay Fraction ◽  
Chemical Properties ◽  
Volcanic Glass ◽  
X Ray Diffraction ◽  
Surface Areas ◽  
Transmission Electron ◽  
Physical And Chemical ◽  
Extractable Iron ◽  
And Chemical Properties

Despite intensive commercial agriculture in the rift zone of Tanzania, mineralogical studies on the soils influenced by volcanic parent materials are scarce. A mineralogical investigation of the soils and two buried ash layers from an irrigated sugar estate was undertaken using X-ray diffraction, transmission electron microscopy and measurements of extractable iron, aluminium and silicon and the specific surface area (SSA) of the clay fraction. The dominant mineral in the sand and silt fractions was sanidine. The clay fractions contained mainly high-defect kaolin, illite and K-feldspar, with small amounts of calcite, talc and gibbsite in some samples. Electron microscopy revealed the presence of tubular and spheroidal halloysite and <0.5µm kaolinite crystals, as well as nanocrystalline material, probably allophane, and volcanic glass. The amounts of ferrihydrite (0.34–1.84%) and allophane (0.52–6.84%) were low in the soils but higher in the buried ash layers. The surface areas of the clay fractions were high (up to 145m2g–1) and it was calculated that 5% allophane constituted 22% of the total SSA. Although all soils were dominated by halloysite and small kaolinite particles, it is likely that the small amounts of allophane with high SSA has a strong effect on their physical and chemical properties.

Characterization of Y/TiO2 Nanoparticles and their Reactivity for CO2 Photoreduction

2011 ◽  
Vol 55-57 ◽  
pp. 1506-1510 ◽  
Author(s):  
Jing Wei ◽  
Xin Tan ◽  
Tao Yu ◽  
Lin Zhao
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Chemical Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uv Illumination ◽  
Transmission Electron ◽  
And Chemical Properties

A series of Y/TiO2nanoparticles (NPs) were synthesized via sol-gel method. The crystal structures, morphologies and chemical properties were characterized using X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM) and X-ray photoelectron spectroscopy (XPS). We investigated the effects of different doping amounts of Y on the reaction of CO2photoreduction. The results shown that 0.1 wt.%Y/TiO2(0.1YT) performed the highest photocatalytic activity, which yielded 384.62 µmol/g∙cat. formaldehyde after 6 h of UV illumination.

scholarly journals Nanostructured Materials for Food Applications: Spectroscopy, Microscopy and Physical Properties

2019 ◽  
Vol 6 (1) ◽  
pp. 26 ◽  
Author(s):  
Shubham Sharma ◽  
Swarna Jaiswal ◽  
Brendan Duffy ◽  
Amit Jaiswal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Nanostructured Materials ◽  
Photoelectron Spectroscopy ◽  
Chemical Properties ◽  
Nanostructured Material ◽  
Correlation Spectroscopy ◽  
Spectroscopic Techniques ◽  
X Ray ◽  
Transmission Electron

Nanotechnology deals with matter of atomic or molecular scale. Other factors that define the character of a nanoparticle are its physical and chemical properties, such as surface area, surface charge, hydrophobicity of the surface, thermal stability of the nanoparticle and its antimicrobial activity. A nanoparticle is usually characterized by using microscopic and spectroscopic techniques. Microscopic techniques are used to characterise the size, shape and location of the nanoparticle by producing an image of the individual nanoparticle. Several techniques, such as scanning electron microscopy (SEM), transmission electron microscopy/high resolution transmission electron microscopy (TEM/HRTEM), atomic force microscopy (AFM) and scanning tunnelling microscopy (STM) have been developed to observe and characterise the surface and structural properties of nanostructured material. Spectroscopic techniques are used to study the interaction of a nanoparticle with electromagnetic radiations as the function of wavelength, such as Raman spectroscopy, UV–Visible spectroscopy, attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), dynamic light scattering spectroscopy (DLS), Zeta potential spectroscopy, X-ray photoelectron spectroscopy (XPS) and X-ray photon correlation spectroscopy. Nanostructured materials have a wide application in the food industry as nanofood, nano-encapsulated probiotics, edible nano-coatings and in active and smart packaging.

scholarly journals Hydrogenation of chlorate ions by commercial carbon supported palladium catalysts—a comparative study

2020 ◽  
Vol 131 (1) ◽  
pp. 129-137
Author(s):  
Emőke Sikora ◽  
Gábor Karacs ◽  
István Kocserha ◽  
Gábor Muránszky ◽  
Béla Fiser ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Palladium Catalysts ◽  
Chemical Properties ◽  
X Ray ◽  
Heterogeneous Catalytic ◽  
Physical Chemical ◽  
Transmission Electron ◽  
Commercial Carbon ◽  
Supported Palladium

Abstract The chlorate elimination potential of three commercial activated carbon supported 10 wt% palladium catalysts (Cat-I, Cat-II and Cat-III) have been compared in heterogeneous catalytic hydrogenation. The physical–chemical properties of the catalysts were characterized by using high-resolution transmission electron microscopy, X-ray diffractometry, Fourier-transform infrared spectroscopy and ζ potential measurements. Chlorate reduction tests have been carried out by applying the same procedure and conditions in each case. The studied catalysts were active, but Cat-I and Cat-III showed higher activity, and eliminated 93% and 91% of chlorate, respectively. Reuse tests have also been carried out to compare the catalysts. Although Cat-I and Cat-III were shown almost equally high activity in the first cycle, the reuse tests showed that Cat-III could have a better applicability.

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