BAMUD Features Demonstration by System View

Direct-sequence code-division multiple access (DS-CDMA) is a frequently used wireless technology in DS-CDMA communications. The conventional DS-CDMA detector follows a single-user detection strategy in which each user is detected separately without regard for the other users. The better strategy is multi-user detection (MUD), where information about multiple users is used to improve detection of each individual user. This paper presents an adaptive multi-user detector converging (for any initialization) to the minimum mean square error (MMSE) detector without requiring training sequences. This blind multi-user detector (BAMUD) requires no more knowledge than does the conventional single-user detector. The structure of adaptive blind detector is simulated by the system design tool SystemView. The aim focus is to verify theoretical knowledge of BAMUD structure using hardware-oriented PC-based model in SystemView

Study Of Decomposition Of Thermoelastic And Non-thermoelastic Martensite In Cu-Zn-Al Alloys

Cu based alloys are considerable traditional material with good shape memory effect. Reversal thermoelastic transformation from parent phase to martensite is necessary requirement for taking place of shape memory effect. The significant phase for taking place shape memory effect in CuZnAl alloy is ordered β phase with ideal ratio of valence electrons to atom e/a = 1.48. The alloys with ratio e/a lesser than 1.42 after quenching from single phase beta region undergo non-thermoelastic martensitic transformation and thereby don’t possess shap e memory effect. This can be obtained by quenching from dual phase α + β region in some alloys. The paper deals with comparison of decomposition at elevated temperatures of thermoelastic and non-thermoelastic martensite to more stable products. Influence of stabilization of martensite on decomposition at elevated temperatures is also studied. Depending up initial state of material and condition of decomposition it could be possible to obtain structure containing α and β or γ phase with miscellaneous morphology and it could be possible to used for modification of definitive structure or for modification of structure before another heat treatment. Study of differences between thermoelastic and non-thermoelastic martensities would be useful for intensification of shape memory properties of Cu based alloys. Note to the reader: On page 02035-p5, several mistakes have been corrected on September 7, 200

Zmiany mikrostruktury i właściwości mechaniczne walcowanej na zimno, dwufazowej stali C-Mn po procesie ciągłego wyżarzania w warunkach laboratoryjnych

The article deals with the influence of annealing parameters on evolution of microstructure and mechanical properties of dual phase steel. Dual phase steel was annealed in laboratory conditions according to the three chosen cycles of annealing: into intercritical region (780°C), into austenite region (920°C) and into austenite region (920°C) by subsequently cooling into intercritical region (780°C) with the hold at the temperature of 495°C. Simulation of annealing regimes by thermo-mechanical simulator Gleeble was done. The obtained microstructure consists from three phases: ferritic matrix, martensite and martensite/ bainite grains. For the microstructure identification the TEM and nanoindentation experiments were performed.Praca dotyczy wpływu parametrów wyżarzania na zmiany mikrostruktury i właściwości mechaniczne stali dwufazowej C-Mn. Stal dwufazową poddano wyżarzaniu w warunkach laboratoryjnych według trzech wybranych cykli: w zakresie między krytycznym (780°C). w obszarze austenitu (920°C) i w obszarze austenitu (920°C) ze schładzaniem do zakresu międzykrytycznego (780°C) przy temperaturze wytrzymania 495°C. Przeprowadzono symulację schematów wyżarzania przy użyciu symulatora obróbki cieplno-plastycznej Gleeble. Uzyskana mikrostruktura składa się z trzech faz: osnowy terrytycznej. martenzytu oraz ziaren martenzytu/bainitu. W celu identyfikacji mikrostruktury wykonano badania metodą TEM oraz nanoindentacji

Stabilization of martensite in α/β{\mathsf \alpha/\beta} microstructure of a Cu-Zn-AI shape-memory alloy

Direct quenching of samples of Cu22Zn4.6A1 alloy from temperatures of an $\alpha/\beta$-field to room temperature causes strong stabilization of martensite in samples with A$_{\rm s}$ (the temperature at which transformation to austenite begins) above room temperature. This can be removed by immediate heating of samples at 170°C after quenching from T$_{\rm Q}$ between 630 and 690°C. Shift of A$_{\rm s}$ to the nominal value depends on time of annealing. In samples quenched from higher temperatures over 690°C the stabilization was not removed. The observation of in situ deformation of martensite in upquenched samples supports the explanation [2] of the decreasing shape memory with increasing quenching temperature by changes in stacking fault energy

Modern methods of analytic electron microscopy in metallurgy

Translated from Czech (Proceedings of Aluminium-2001, Decin, Czech Republic, Sept 2001)SIGLEAvailable from British Library Document Supply Centre-DSC:9023.190(10403)T / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Shape Memory Effect in CuZnAl Alloys Quenched from Alfa + Beta Phase Zone

Shape memory effect (SME) is studied in dual phase α / β microstructures with changing volume fraction of martensite obtained by quenching from various temperatures in α/β field of CuZnAl alloy. It was find out that with increasing amount of martensite SME is decreasing along with composition changes, decreasing of monoclinicity in M18R martensite and decreasing mean dimensions of nearest-neighbour antiphase domains (NNAPD) and next- nearest-neighbour antiphase domains (NNNAPD)

Using electron microscopic methods in fractography and examination of phase transformations

19.00; Translated from Czech (Hutn. Listy 1987 v. 42(5) p. 343-351)Available from British Library Document Supply Centre- DSC:9023.19(VR--3462)T / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo