			Home About us Contact

Low Magnification (low + magnification)

Distribution by Scientific Domains

Polymers and Materials Science	50%
Medical Sciences	50%

Selected Abstracts

Thermal Barrier Coatings Design with Increased Reflectivity and Lower Thermal Conductivity for High-Temperature Turbine Applications

INTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 2 2006
Matthew J. Kelly
High reflectance thermal barrier coatings consisting of 7% Yittria-Stabilized Zirconia (7YSZ) and Al2O3 were deposited by co-evaporation using electron beam physical vapor deposition (EB-PVD). Multilayer 7YSZ and Al2O3 coatings with fixed layer spacing showed a 73% infrared reflectance maxima at 1.85 ,m wavelength. The variable 7YSZ and Al2O3 multilayer coatings showed an increase in reflection spectrum from 1 to 2.75 ,m. Preliminary results suggest that coating reflectance can be tailored to achieve increased reflectance over a desired wavelength range by controlling the thickness of the individual layers. In addition, microstructural enhancements were also used to produce low thermal conductive and high hemispherical reflective thermal barrier coatings (TBCs) in which the coating flux was periodically interrupted creating modulated strain fields within the TBC. TBC showed no macrostructural differences in the grain size or faceted surface morphology at low magnification as compared with standard TBC. The residual stress state was determined to be compressive in all of the TBC samples, and was found to decrease with increasing number of modulations. The average thermal conductivity was shown to decrease approximately 30% from 1.8 to 1.2 W/m-K for the 20-layer monolithic TBC after 2 h of testing at 1316°C. Monolithic modulated TBC also resulted in a 28% increase in the hemispherical reflectance, and increased with increasing total number of modulations. [source]

Extramammary Paget's disease mimicking acantholytic squamous cell carcinoma in situ: a case report

JOURNAL OF CUTANEOUS PATHOLOGY, Issue 6 2010
Xufeng Du
Background: Extramammary Paget's disease (EMPD) is an uncommon skin neoplasm characterized by Paget's cells with pale-staining cytoplasm in the epidermis, and cases with distinguished acantholysis but lacking characteristic Paget's cells were rarely reported in the literature. Methods: An 80-year-old male with lesion on scrotum was screened histologically and immunohistologically for the diagnosis of his tumor. Results: Histological examination showed acanthosis with cellular atypia and focal acantholysis, consistent with acantholytic squamous cell carcinoma in situ (SCCIS). No characteristic Paget's cells were observed in low magnification. Immunohistochemical staining showed carcinoembryonic antigen (CEA), cytokeratin 7 (CK7) and cytokeratin 8 (CK8) to be strongly expressed in the nests and singly arranged large tumor cells, and the surrounding epidermis was positive for CK5/6 and negative for CEA. Sporadic periodic acid-schiff (PAS)-positive cells could be seen in some areas. Conclusions: These findings strongly indicated the diagnosis of EMPD mimicking acantholytic SCCIS. Du X, Yin X, Zhou N, Zhang G, Shi H, Cao S. Extramammary Paget's disease mimicking acantholytic squamous cell carcinoma in situ: a case report. [source]

Morphology Change of Undoped and Sulfate-Ion-Doped Yttria Powders during Firing

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 3 2004
Ikegami Takayasu
Morphologic changes that occurred during firing in undoped and sulfate-ion-doped yttria powders were examined in the present study. Clear scanning electron microscopy (SEM) images of uncoated insulators were achieved and charging of electrons was avoided by observing small samples, throughout which most of the electrons of the incident beam penetrated. SEM observation and firing of the samples were repeated several times. Searching the observed areas or particles started at low magnification, with the aid of photographs taken earlier. The sulfate-ion dopant inhibited volume diffusion and/or grain-boundary diffusion, and then particle growth of the sulfate-ion-doped yttria proceeded by surface diffusion or evaporation,condensation along with pore growth, which resulted in collapse of the agglomerates of primary particles. Although most of the other particles exhibited slight pore growth along with particle growth at temperatures as low as 800°C, a hardening of the agglomerated particles, because of pore elimination by volume diffusion and/or grain-boundary diffusion, occurred at temperatures >850°C. [source]

Instrument-, age- and site-dependent variations of dermoscopic patterns of congenital melanocytic naevi: a multicentre study

BRITISH JOURNAL OF DERMATOLOGY, Issue 1 2006
S. Seidenari
Summary Background, Recently, we identified and described dermoscopic aspects, present with a higher frequency in congenital melanocytic lesions with respect to acquired naevi. We also classified small- and medium-sized congenital naevi (CN) into nine subtypes according to their macroscopic and dermoscopic aspects. Objectives, Because the recognition of dermoscopic features may be instrument dependent, in this study, we wanted to check whether dermoscopic patterns specific for CN can be identified in digital images acquired by means of different instruments. We also wanted to check the validity of our previously proposed classification and assess possible age- and site-dependent variations of dermoscopic patterns and naevus subtypes. Patients/methods, Images corresponding to 384 small- or medium-sized CN were collected in eight different centres employing four different instruments. Lesion images were evaluated and checked for the presence of specific dermoscopic criteria, classified, and compared with a database of 350 acquired naevi. Results, Specific and unspecific dermoscopic features were identifiable in images acquired by means of all four instrument types. The mean number of identified features per lesion did not vary according to the instrument employed for the acquisition of the images; however, it was lower for lesions recorded employing low magnifications. The previously proposed classification was easily applied to the whole image database. The variegated naevus type was identified as a highly specific clinical/dermoscopic pattern. Dermoscopic features varied according to age and location. The globular type prevailed in subjects under 11 years of age and on the trunk, whereas the majority of reticular lesions were located on the limbs. Conclusions, Because definite clinical and histological criteria for the diagnosis of the congenital nature of naevi are lacking, the use of dermoscopy can be of great help in identifying those lesions where the presence of specific dermoscopic features makes the diagnosis of CN more likely. Moreover, dermoscopy can be useful both for the classification of lesions already identified as congenital according to definite clinical and anamnestic data and for a possible correlation of naevus phenotype and dermoscopic patterns to the risk of developing a malignant melanoma in prospective studies. [source]