scholarly journals Temperature effects on chemical structure and motion in coal. Final report

1996 ◽  
Author(s):  
G.E. Maciel
Keyword(s):  
Temperature Effects ◽  
Chemical Structure ◽  
Final Report ◽  
Structure And Motion

Temperature Effects on Piezoelectric Wafer Active Sensors

2015 ◽  
Author(s):  
Linlin Ma ◽  
Xiaoyi Sun ◽  
Bin Lin ◽  
Lingyu Yu
Keyword(s):  
Analytical Model ◽  
Temperature Effects ◽  
Spent Nuclear Fuel ◽  
Pressure Vessels ◽  
Ultrasonic Waves ◽  
Final Report ◽  
Active Sensors ◽  
Sensing System ◽  
Piezoelectric Wafer Active Sensors ◽  
Piezoelectric Wafer

This paper discusses the temperature effects of using piezoelectric wafer active sensors (PWAS) technologies for structural health monitoring (SHM) in pressure vessels and piping (PVP) applications, e.g. dry cast storage system (DCSS). The research into monitoring of DCSS health has experienced a dramatic increase following the issuance of the Blue Ribbon Commission (BRC) on America’s Nuclear Future Final Report in 2012. The interim storage of spent nuclear fuel from reactor sites has gained additional importance and urgency for resolving waste-management-related technical issues. PWAS have emerged as one of the major SHM technologies developed particularly for generating and receiving acousto-ultrasonic waves for the purpose of continuous monitoring and diagnosis. Durability and survivability of PWAS under temperature effects was first tested in experiments. The analytical model of PWAS based sensor and sensing system under temperature effects was then developed. This paper compared the analytical model and experimental results of PWAS under temperature changes. Since the environmental variability of a sensing system includes changes in both the sensors and the sensing methodology including acoustic emission (AE), guided ultrasonic waves (GUW), and electro-mechanical impedance spectroscopy (EMIS), we also performed several temperature exposure with different PWAS sensing configurations under a controlled oven. The potential of PWAS for DCSS applications has been explored. The paper ends with conclusions and suggestions for further work.

Amended Final Report On the Safety Assessment of Pentaerythrityl Rosinate

1998 ◽  
Vol 17 (4_suppl) ◽  
pp. 83-94
Author(s):  
F.A. Andersen
Keyword(s):  
Chemical Structure ◽  
Safety Assessment ◽  
Additional Data ◽  
Developmental Toxicity ◽  
Toxicity Study ◽  
Final Report ◽  
Cosmetic Products ◽  
Carcinogenicity Study ◽  
Ocular Irritation ◽  
Dermal Irritation

Pentaterythrityl Rosinate (previously called Pentaerythritol Rosinate) is the ester of rosin acids with the polyol pentaerythritol. It is used as a skin conditioning agent-emollient and viscosity increasing agent-nonaqueous in a few cosmetic formulations. In a previous safety assessment, it was concluded that the available data were insufficient to support the safety of this ingredient in cosmetic products. Additional data needed included: concentration of use, source and method of manufacture, chemistry (ultraviolet [UV] spectral analysis, pH, and impurities), ocular irritation, human dermal irritation and sensitization, and photosensitization (only if Pentaerythritol Rosinate absorbs UVA or UVB light). It was also noted that the carcinogenic potential of this ingredient was still of concern because of the low concentration tested in the available carcinogenicity study. Additional data were received. This ingredient is produced by the fractional distillation of crude tall oil to form rosin, which is then esterified with monopentaerythritol. It is typically used at concentrations of 0. 5-10%. It does not significantly absorb in the UVA or UVB portion of the spectrum. Formulations with 10% Pentaerythrityl Rosinate produced only minimal ocular irritation. Likewise tests of formulations with the ingredient at concentations of 7-9.2% resulted in minimal dermal irritation. The ingredient was nonsensitizing in animal maximization tests. Clinical tests of formulations with the ingredient at concentrations of 7-9.6% resulted in neither irritation nor sensitization. No data, however, were provided on possible impurities. Absent information on the actual chemical structure, the lack of information on impurities was considered significant. On further review, a single carcinogenicity study with negative results reported in the earlier safety assessment was considered inadequate. The absence of genotoxicity data was also considered significant. The lack of impurity and chemical structure information also raised a concern about the need for reproductive and developmental toxicity data. On the basis of this further review, it was concluded that the available data are still insufficient to support the safety of this ingredient in cosmetic products. Additional data needed include: (1) two genotoxicity assays, at least one in a mammalian system; if positive, then a 2-year dermal carcinogenicity study using National Toxicology Program (NTP) methods is needed; (2) dermal absorption; if significantly absorbed, then both a 28-day dermal toxicity study and a reproductive and developmental toxicity study may be needed; and (3) chemical properties, including structure and impurities.

Inelastic Electron-Matter Interactions

1978 ◽  
Vol 36 (3) ◽  
pp. 259-267
Author(s):  
J. Silcox
Keyword(s):  
Electron Microscope ◽  
Energy Loss ◽  
Chemical Structure ◽  
Inelastic Electron ◽  
Primary Concern ◽  
Unique Probe ◽  
Introductory Paper ◽  
Elastic Processes ◽  
Experimental Level ◽  
Inelastic Processes

In this introductory paper, my primary concern will be in identifying and outlining the various types of inelastic processes resulting from the interaction of electrons with matter. Elastic processes are understood reasonably well at the present experimental level and can be regarded as giving information on spatial arrangements. We need not consider them here. Inelastic processes do contain information of considerable value which reflect the electronic and chemical structure of the sample. In combination with the spatial resolution of the electron microscope, a unique probe of materials is finally emerging (Hillier 1943, Watanabe 1955, Castaing and Henri 1962, Crewe 1966, Wittry, Ferrier and Cosslett 1969, Isaacson and Johnson 1975, Egerton, Rossouw and Whelan 1976, Kokubo and Iwatsuki 1976, Colliex, Cosslett, Leapman and Trebbia 1977). We first review some scattering terminology by way of background and to identify some of the more interesting and significant features of energy loss electrons and then go on to discuss examples of studies of the type of phenomena encountered. Finally we will comment on some of the experimental factors encountered.

Characterization of carbides in M50NiL

1991 ◽  
Vol 49 ◽  
pp. 606-607
Author(s):  
L. S. Lin ◽  
K. P. Gumz ◽  
A. V. Karg ◽  
C. C. Law
Keyword(s):  
Temperature Effects ◽  
Base Composition ◽  
Lattice Parameter ◽  
Control Surface ◽  
Carbide Formation ◽  
Particle Sizes ◽  
Low Carbon ◽  
Fee Structure ◽  
Heat Treated

Carbon and temperature effects on carbide formation in the carburized zone of M50NiL are of great importance because they can be used to control surface properties of bearings. A series of homogeneous alloys (with M50NiL as base composition) containing various levels of carbon in the range of 0.15% to 1.5% (in wt.%) and heat treated at temperatures between 650°C to 1100°C were selected for characterizations. Eleven samples were chosen for carbide characterization and chemical analysis and their identifications are listed in Table 1.Five different carbides consisting of M6C, M2C, M7C3 and M23C6 were found in all eleven samples examined as shown in Table 1. M6C carbides (with least carbon) were found to be the major carbide in low carbon alloys (<0.3% C) and their amounts decreased as the carbon content increased. In sample C (0.3% C), most particles (95%) encountered were M6C carbide with a particle sizes range between 0.05 to 0.25 um. The M6C carbide are enriched in both Mo and Fe and have a fee structure with lattice parameter a=1.105 nm (Figure 1).

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