Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 6
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

In the article we described the evolution of optical technology from lens-type microscopes working in far-field to SNOM (Scanning

Near-Field Optical Microscopy) constructions. We considered two systems elaborated in our laboratory, namely PSTM system (Photon Scanning Tunelling Microscope) and SNOM system. In both systems we obtained subwavelength resolution. Some details about optical point probe technology in both systems are given and experimental results presented.

Go to article

Authors and Affiliations

J. Radojewski
Download PDF Download RIS Download Bibtex

Abstract

The paper presents the microscopic and mechanoacoustic study of degradation processes of the porcelain material C 130 type.

This kind of material is used in the production of the most durable and reliable electrotechnical elements. Raw material composition of the studied porcelain was modified. This had an impact on the inner properties, cohesion and – in consequence – on operational properties of the material.

Using mechanical-acoustic and microscopic methods of testing of small-size samples that were subjected to compression, it was possible to distinguish successive stages of degradation of the porcelain structure. These stages were generally typical of the porcelain materials. In the authors’ opinion, they are connected to the ageing process happening over many years of work under operating conditions.

Optimization of composition and technological properties – important during technological processes – resulted in a slight decrease in inner cohesion of the porcelain. When compared to the reference material – typical domestic C 130 material, mechanical strength was somewhat lower. Carried out investigations proved that resistance of the investigated material to the ageing degradation process – during long term operation – also decreased. The improvement of technological parameters and the reduction in the number of defective elements occurred simultaneously with some decrease in the operational parameters of the material. To restore their initial high level, further work is needed to optimize the raw material composition of the porcelain.

Go to article

Authors and Affiliations

P. Ranachowski
Z. Ranachowski
K. Wieczorek
M. Jaroszewski
S. Kudela Jr
Download PDF Download RIS Download Bibtex

Abstract

In this paper the authors propose a decision support system for automatic blood smear analysis based on microscopic images. The images are pre-processed in order to remove irrelevant elements and to enhance the most important ones – the healthy blood cells (erythrocytes) and the pathologic ones (echinocytes). The separated blood cells are analysed in terms of their most important features by the eigenfaces method. The features are the basis for designing the neural network classifier, learned to distinguish between erythrocytes and echinocytes. As the result, the proposed system is able to analyse the smear blood images in a fully automatic way and to deliver information on the number and statistics of the red blood cells, both healthy and pathologic. The system was examined in two case studies, involving the canine and human blood, and then consulted with the experienced medicine specialists. The accuracy of classification of red blood cells into erythrocytes and echinocytes reaches 96%.

Go to article

Authors and Affiliations

Michał Grochowski
Michał Wąsowicz
Agnieszka Mikołajczyk
Mateusz Ficek
Marek Kulka
Download PDF Download RIS Download Bibtex

Abstract

The objective of the investigation was to identify surface roughness after turning with wedges of coated sintered carbide. The investigation included predicting the average surface roughness in the dry machining of Duplex Stainless Steel (DSS) and the determination of load curves together with roughness profiles for various cutting conditions. The load curves and roughness profiles for various cutting wedges and variable cutting parameters were compared. It has been shown that dry cutting leads to a decrease in friction for lubricated surfaces, providing a small initial contact area where the surface is contacted. The study has been performed within a production facility during the production of electric motor parts and deep-well pumps.

Go to article

Authors and Affiliations

Grzegorz M. Królczyk
Stanisław Legutko
Download PDF Download RIS Download Bibtex

Abstract

Automotive industry is constantly interested in building cars made of light and high strength parts in order to reduce the emission levels, the fuel consumption and minimize the effects of a car crash. Some parts may be made of lighter materials, but the steel ones must compensate the strength needed for the car body. Research is made for finding new materials showing high strength combined with high ductility. Among them, transformation – induced – plasticity steels are of great interest, efforts being made to improve their characteristics. A new composition of such a steel is presented, its features being compared with those of three other steels of the same class and category. Optical microscopy at different magnifications is performed, together with Vickers hardness test. Structural particularities are found for each tested steel, justified by their own chemical compositions. The new steel reveals important characteristics: besides the mainly bainitic structure, it has both larger ferritic areas and amounts of retained austenite, making him proper for further study.
Go to article

Authors and Affiliations

M.C. Pantilimon
1
ORCID: ORCID
A.C. Berbecaru
1
ORCID: ORCID
G. Coman
1
ORCID: ORCID
M.G. Sohaciu
1
ORCID: ORCID
R.E. Dumitrescu
1
ORCID: ORCID
S. Ciucă
1
ORCID: ORCID
I.A. Gherghescu
1
ORCID: ORCID
C. Predescu
1
ORCID: ORCID

  1. Politehnica University of Bucharest, Faculty of Materials Science and Engineering, Splaiul Independenței No. 313, Bucharest 060042, Romania
Download PDF Download RIS Download Bibtex

Abstract

Metal nanoshells are a type of nanoparticle composed by a dielectric core and a metallic coating. These nanoparticles have stimulated interest due to their remarkable optical properties. In common with metal colloids, they show distinctive absorption peaks at specific wavelengths due to surface plasmon resonance. However, unlike bare metal colloids, the wavelengths at which resonance occurs can be tuned by changing the core radius and coating thickness. One basic application of such property is in medicine, where it is hoped that nanoshells with absorption peaks in the near−infrared can be attached to cancerous cells. In this paper, we study the changes of optical response in visible and near infrared wavelengths from single to randomly distributed clusters of nanoshells. The results were obtained using a novel formulation of Mie theory in evanescent wave conditions, with a finite−difference time−domain (FDTD) simulation and experimentally on BaTiO3−gold nanoshells using a scanning near−optical microscope. The results show that the optical signal of a randomly distributed cluster of nanoshells can be supplementary tuned with respect to the case of single nanoshell depending by the geometric configuration of the clusters.

Go to article

Authors and Affiliations

A. Cricenti
M. Luce
D. Moroni
O. Salvetti
M. D’Acunto

This page uses 'cookies'. Learn more