Degradation of cellulose with high voltage electrons

1978 ◽  
Vol 36 (1) ◽  
pp. 494-495
Author(s):  
P. A. Tucker ◽  
S. P. Hersh ◽  
G. M. Berry ◽  
N. Kerr ◽  
D. M. Mcelwain
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Chemical Properties ◽  
Cotton Fabrics ◽  
Radiation Doses ◽  
Diffraction Patterns ◽  
Engineering Corporation ◽  
High Voltage Engineering ◽  
Initial Results ◽  
And Chemical Properties

As part of a larger study of the degradation of polymers, cotton cellulose is being intentionally degraded with high voltage electrons. The initial results were reported earlier (1). Because of the implications of this study to the electron microscopy of beam sensitive materials, special attention is being given to relating these studies to electron microscopy.Generally, the microscopist's main, and perhaps only, information on specimen degradation is that provided by diminution of the electron diffraction pattern. It will be shown in this paper that even though specimen diffraction patterns are only slightly altered, the mechanical and chemical properties are vastly changed.To produce degraded fabrics having strength losses of 75% or more, cotton fabrics were exposed to radiation doses of 50 and 100 Mrad at 550 kV in an electron accelerator manufactured by High Voltage Engineering Corporation. Properties of such cotton fabrics before (i.e., control) and after exposure to 50 and 100 Mrad dosages are presented in Table I.

scholarly journals PHYSICAL AND CHEMICAL STUDIES OF OVERROOF ROCKS OF CLAY SHALES OF THE DZHERDANAK DEPOSIT

2021 ◽  
pp. 16-21
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Chemical Properties ◽  
Mineralogical Composition ◽  
Physical And Chemical Properties ◽  
X Ray ◽  
Clay Shales ◽  
Chemical Studies ◽  
Physical And Chemical ◽  
And Chemical Properties

The purpose of this study is study of the physical and chemical properties of the overburden of the Dzherdanak deposit. The chemical and mineralogical composition of the overburden of the Djerdanak deposit has been studied by the methods of X-ray and thermography, electron microscopy and infrared spectroscopy. The main phases are quartz, kaolinite and muscovite. The study of the fine structure of the rock under an electron microscope showed the homogeneity of the rock with pronounced uniform inclusions, which is preserved even after firing. Changes in the rock after firing at 1050 °C have been determined. The formation of mullite at this temperature has been established.

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.

Failure Analysis of High Pressure Container using Fractography and Material Morphology

2018 ◽  
Vol 773 ◽  
pp. 287-291
Author(s):  
Eui Soo Kim
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Pressure ◽  
Failure Analysis ◽  
Large Scale ◽  
Chemical Properties ◽  
Accurate Analysis ◽  
Internal Pressures ◽  
Scanning Electron ◽  
And Chemical Properties

High-pressure gas containers must be able to withstand high internal pressures because they store compressed gases. Otherwise, cracks or defects may lead to an explosion, which may in turn lead to a large-scale disaster. Therefore, accurate analysis of the causes of cracks or defects and various techniques for detecting cracks or defects are needed. In this research, we analyzed the failure mechanism of a high-pressure gas container through fractography using scanning electron microscopy and optical microscopy and through measurements of their mechanical and chemical properties.

scholarly journals Biogenic Formation of As-S Nanotubes by Diverse Shewanella Strains

2009 ◽  
Vol 75 (21) ◽  
pp. 6896-6899 ◽  
Author(s):  
Shenghua Jiang ◽  
Ji-Hoon Lee ◽  
Min-Gyu Kim ◽  
Nosang V. Myung ◽  
James K. Fredrickson ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Reduction Rate ◽  
Shewanella Oneidensis ◽  
Chemical Properties ◽  
Anaerobic Conditions ◽  
X Ray ◽  
Shewanella Alga ◽  
X Ray Absorption ◽  
And Chemical Properties

ABSTRACT Shewanella sp. strain HN-41 was previously shown to produce novel, photoactive, As-S nanotubes via the reduction of As(V) and S2O3 2− under anaerobic conditions. To determine if this ability was unique to this bacterium, 10 different Shewanella strains, including Shewanella sp. strain HN-41, Shewanella sp. strain PV-4, Shewanella alga BrY, Shewanella amazonensis SB2B, Shewanella denitrificans OS217, Shewanella oneidensis MR-1, Shewanella putrefaciens CN-32, S. putrefaciens IR-1, S. putrefaciens SP200, and S. putrefaciens W3-6-1, were examined for production of As-S nanotubes under standardized conditions. Of the 10 strains examined, three formed As-S nanotubes like those of strain HN-41. While Shewanella sp. strain HN-41 and S. putrefaciens CN-32 rapidly formed As-S precipitates in 7 days, strains S. alga BrY and S. oneidensis MR-1 reduced As(V) at a much lower rate and formed yellow As-S after 30 days. Electron microscopy, energy-dispersive X-ray spectroscopy, and extended X-ray absorption fine-structure spectroscopy analyses showed that the morphological and chemical properties of As-S formed by strains S. putrefaciens CN-32, S. alga BrY, and S. oneidensis MR-1 were similar to those previously determined for Shewanella sp. strain HN-41 As-S nanotubes. These studies indicated that the formation of As-S nanotubes is widespread among Shewanella strains and is closely related to bacterial growth and the reduction rate of As(V) and thiosulfate.

scholarly journals A Review of Morphological and Chemical Properties of Porous Asphalt

CONSTRUCTION ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 45-49
Author(s):  
N.E. Jasni ◽  
Khairil Azman Masri ◽  
R.P. Jaya
Keyword(s):  
Electron Microscopy ◽  
Chemical Composition ◽  
Asphalt Mixture ◽  
Chemical Properties ◽  
Fine Aggregate ◽  
Air Voids ◽  
Porous Asphalt ◽  
X Ray ◽  
Scanning Electron ◽  
And Chemical Properties

Porous asphalt mixture is also known as gap graded mixture with less amount of fine aggregate has led the mixture contains high air voids, tends to make the mixture less durable and high porousity. Hence, past researchers has investigate on how to increase the strength of porous asphalt mixture by the addition of additive such as fiber and  nanomaterials. The chemical and physical properties of porous asphalt mixture was highlighted in this paper to compare its structure, the bonding between the materials and its chemical composition that exist. This paper reviews on how additive affect the asphalt mixture in terms of Scanning Electron Microscopy (SEM), X-Ray Diffractions (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). These tests are selected to improve the asphalt mixture according to the morphological and chemical properties of porous asphalt. This study is expected to identify the morphological and chemical composition of the materials in asphalt mixture.

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.

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