Wyniki wyszukiwania - BazTech

1

Solid-state welding of ultrafine grained copper rods

Morawiński Łukasz, Jasiński Cezary, Ciemiorek Marta, Chmielewski Tomasz, Olejnik Lech, Lewandowska Małgorzata

Archives of Civil and Mechanical Engineering

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2021

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Vol. 21, no. 3

31--43

EN

The article focuses on the Direct Drive Rotary Friction Welding of ultrafine-grained copper rods, which feature increased mechanical properties and good electrical properties, yet are limited in size. The use of UFG metals is often limited by the too small dimensions of semi-finished elements produced by SPD methods. Therefore, the production of finished machine parts from UFG metals is currently economically unjustified. Dismissal of dimensional limitations can be done by introducing joining to technological processes. The proposed joining method does not lead to a melting of the material in the joining zone or excessive degradation of the UFG microstructure. To obtain the best results, the research used the method of low-energy welding of two kinds of specimens: with a flat or a conical contact surface. In the article, the authors present, by means of metallographic microsections and microhardness measurements, the influence of rotational speed, welding pressure and conical shape contact surface on the quality of the obtained joints. The conducted research made it possible to obtain good quality joints whose microhardness is reduced only by about 10% in comparison with the base material and the tensile strength dropped from only 397–358 MPa.

2

Interpretation of Gamma Index for Quality Assurance of Simultaneously Integrated Boost (SIB) IMRT Plans for Head and Neck Carcinoma

Atiq M., Atiq A., Iqbal K., Shamsi Q., Andleeb F., Buzdar S. A.

Polish Journal of Medical Physics and Engineering

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2017

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Vol. 23, Iss. 4

93--97

EN

Objective: The Gamma Index is prerequisite to estimate point-by-point difference between measured and calculated dose distribution in terms of both Distance to Agreement (DTA) and Dose Difference (DD). This study aims to inquire what percentage of pixels passing a certain criteria assure a good quality plan and suggest gamma index as efficient mechanism for dose verification of Simultaneous Integrated Boost Intensity Modulated Radiotherapy plans. Method: In this study, dose was calculated for 14 head and neck patients and IMRT Quality Assurance was performed with portal dosimetry using the Eclipse treatment planning system. Eclipse software has a Gamma analysis function to compare measured and calculated dose distribution. Plans of this study were deemed acceptable when passing rate was 95% using tolerance for Distance to agreement (DTA) as 3mm and Dose Difference (DD) as 5%. Result and Conclusion: Thirteen cases pass tolerance criteria of 95% set by our institution. Confidence Limit for DD is 9.3% and for gamma criteria our local CL came out to be 2.0% (i.e., 98.0% passing). Lack of correlation was found between DD and γ passing rate with R2 of 0.0509. Our findings underline the importance of gamma analysis method to predict the quality of dose calculation. Passing rate of 95% is achieved in 93% of cases which is adequate level of accuracy for analyzed plans thus assuring the robustness of SIB IMRT treatment technique. This study can be extended to investigate gamma criteria of 5%/3mm for different tumor localities and to explore confidence limit on target volumes of small extent and simple geometry.

3

Diagnostic systems for the nuclear fusion and plasma research in the PF-24 plasma focus laboratory at the IFJ PAN

Marciniak Ł., Wójcik-Gargula A., Kulińska A., Bielecki J., Wiącek U.

Nukleonika

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2016

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Vol. 61, No. 4

413--418

EN

This paper presents a set of diagnostics dedicated to PF-24 – new medium size – plasma focus (PF) device built and operated at the Institute of Nuclear Physics Polish Academy of Sciences (IFJ PAN). The PF-24 can operate at energy level up to 93 kJ and charging voltage up to 40 kV. Each condenser is connected with a specially designed spark gap with a very small jitter, which ensures a high efficiency and a low current rise time. The working parameters of PF-24 generator make it a suitable tool for testing new detection systems to be used in fusion research. Four types of such detection systems are presented in this article: three diagnostic systems used to measure electric quantities (Rogowski coil, magnetic probe, capacitance probe), neutron counter based on beryllium activation, fast neutron pinhole camera based on small-area BCF-12 plastic scintillation detectors and high-speed four-frame soft X-ray camera with microchannel plate.

4

Automatic epilepsy detection using wavelet-based nonlinear analysis and optimized SVM

Li M., Chen W., Zhang T.

Biocybernetics and Biomedical Engineering

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2016

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Vol. 36, no. 4

708--718

EN

Aiming at the problems of low accuracy, poor universality and functional singleness for seizure detection, an effective approach using wavelet-based non-linear analysis and genetic algorithm optimized support vector machine (GA-SVM) is proposed to deal with five challenging classification problems in this study. Instead of the traditional discrete wavelet transform (DWT), we attempt to explore the ability of double-density discrete wavelet transform (DD-DWT) to decompose the original EEG into specific sub-bands. The Hurst exponent (HE) and fuzzy entropy (FuzzyEn) are extracted as input features and then fed into two classifiers. On using these ranking non-linear features, the GA-SVM configured with fewer features is found to achieve the prominent classification performance for various combinations such as AB-CD-E, A-D-E, ABCD-E, C-E and D-E, achieving accuracies of 99.36%, 99.60%, 99.40%, 100% and 100%, respectively. The results have indicated that our scheme is not only appropriate in solving problems with multiple classes but also of lower complexity and better expansibility. These characteristics would make this method become an attractive alternative for actual clinical diagnosis.

5

Analiza wydajności ruterów SoHo z alternatywnym oprogramowaniem

Aleksieva V., Valchanov H., Długosz T., Wróbel R.

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

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2014

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nr 1

10--12

PL

Oprogramowanie rozszerzające funkcjonalność działania ruterów SoHo jest bardzo popularne. Wpływa na to ma tylko wspomniana funkcjonalność, ale także skalowalność, jak i możliwość instalacji niektórych wersji na pamięci flash. Przedstawiono wyniki prac nad oprogramowaniem otwartego źródła (w tym przypadku DD-WRT) i jego wpływ na pasmo.

EN

The software, extending the functionality of SoHo routers is very popular. This affects not only the mentioned functionality, but also scalability and the ability to install few versions on a flash memory. This article presents the results of work on open source software (in this case DD-WRT) and its impact on the band.

6

Diagnostyka uszkodzeń w systemach SoC oparta na monitorowaniu średniej wartości prądu /DD

Dziurdzia P.

Elektronika : konstrukcje, technologie, zastosowania

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2006

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Vol. 47, nr 11

23-25

PL

Przedstawiono możliwości wykorzystania monitorowania średniej wartości prądu /DD do śledzenia poprawnego funkcjonowania systemów SoC. Zaprezentowano zalety monitorowania prądu /DD do wykrywania błędów dynamicznych związanych z naruszeniem szybkości narastania i opadania sygnałów zegarowych, skutkujących następnie zwiększonymi czasami propagacji. Przedstawiono również wpływ uszkodzeń trwałych, objawiających się zwiększonymi pojemnościami pasożytniczymi lub zmniejszonymi rezystancjami pomiędzy węzłami układu na przebieg sygnałów napięciowych i odpowiadających im wartościom średniego prądu /DD.

EN

In the work possible applications of monitoring of mean value of lt current to following up SoC operation is shown. Benefits of /DD rent monitoring in detecting timing constraints violations connected with transition times of clock signals manifested next in increased propagation delays are presented. Also effects of permanent defects resulting from increased parasitic capacitances and decreased parasitic resistances between nodes of the SoC cells are considered, their influence on voltage signals and corresponding mean values of /DD current is shown. At the end results of simulations for selected defects implemented in 0.35 µm technology are discussed.

7

Nowa generacja autobusów lokalnych i miejskich koncernu NeoMAN. Cz. 2

Rusak Z.

Autobusy : technika, eksploatacja, systemy transportowe

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2004

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R. 5, nr 9

16-19

PL

Mimo, że niskopodłogowe autobusy miejskie trzeciej generacji sprzedają się bardzo dobrze MAN podjął decyzję o ich modernizacji. Celem zmian w stylistyce nadwozia jest jednoznaczna identyfikacja produktu z pozostałymi autobusami produkowanymi przez MAN-a. W artykule omówiono zmiany stylistyczne nadwozia i stanowiska kierowcy, a także poprawki techniczne w układzie napędowym takich modeli jak: MAN Lion's City, MAN Lion's City DD, MAN Lion's City T, Neoplan N 4516 T.

8

Microwave harmonic generation in fiber-optical links

Hilt A.

Journal of Telecommunications and Information Technology

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2002

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nr 1

22-28

EN

Optical transmission of microwave (MW) and millimeter-wave (MMW) signals has become an intensive research area in the last decade. There is a growing interest in optical processing of MW signals [1,2], phased array applications [3] and wireless distribution of broadband data in fiber-fed MMW subscriber access systems [4 - 10]. This paper extends the existing models of MW/MMW optical links that are based on optical intensity [10, 11]. The model is suitable for estimating harmonic levels of the MW modulation signal generated in the optical path. Considering a MW fiber-optic link both the optical transmitter and the receiver are responsible for harmonic generation. Furthermore, the optical fiber itself inserted between the transmitter and receiver induces harmincs due to dispersion. Exact modelling of harmonic generation requires a calculation based on the optical field instead of on a purely intensity basis [12 -14].