Plastic deformation in a multifunctional Ti-Nb-Ta-Zr-O alloy

Mechanisms for plastic deformation in the newly developed Ti-24 at. pct (Ta + Nb + V)-(Zr,Hf)-O alloys (Gum Metal) were investigated in relation to their unique properties. Transmission electron microscopy revealed that the microstructure after deformation was characterized by highly distorted crystal images, which are accompanied by numerous “giant faults.” Such plastic behavior implies that a large amount of elastic stain energy was stored discretely and hierarchically during cold working. Calculated elastic constants of the Ti-X (Nb,Ta,Mo,V) binary systems predicted that Young’s modulus in 〈001〉 and shear moduli along some directions including slip systems in a bcc crystal were extraordinary small. The low modulus not only well explains the highly distorted microstructure observed in the cold-worked specimens, but also signifies that ideal shear strength of the developed alloys is a very small value, which is close to the practical strength required for plastic deformation in the alloy. This implies that the giant faults observed in the deformed specimen were formed without the aid of dislocation glide.     

Evaluation of hydrological processes in a mountainous small basin using a quinone biomarker.

An applicability of quinone biomarker to the analysis of hillslope runoff was investigated. At first, quinone profiles of three streams as well as a hillslope runoff in a forested headwater catchment were compared. The quinone composition of hillslope runoff differed from others. Moreover, there were remarkable differences in quinone profile of hillslope runoff under different rainfall conditions. Then, the behavior of quinone biomarker during the increase and decrease of hillslope runoff after a rainfall event was examined. The fractional changes in Q-9 (H2), Q-10 (H2), Q-11, MK-6 and MK-10 suggested the effect of interflow.     

Testing interconnections to static RAMs

A method for testing the interconnections of ordinary static RAMs with a processor that has a boundary-scan register and an IEEE 1149.1 test-access port is described. The method uses an enhanced boundary-scan-register design that manipulates the test-access-port controller states to meet the static RAM's timing constraints. The implementation is more economical than a boundary-scan register that strictly conforms to IEEE 1149.1. Test operation is more efficient, requiring a third of the number of scan operations. A test-pattern set and a method for detecting and diagnosing the interconnection faults on RAMs are also described. The test-pattern set can be enhanced as necessary to increase coverage and diagnosing ability and to handle any RAM configuration. The implementation of the proposed boundary-scan register is independent of the test algorithm used. It is believed that the methodology is extendable to RAMs that use an access protocol different from the one described, for example dynamic RAMs and synchronous RAMs     

Monolithic integration of a 5.3 GHz regenerative frequency divider using a standard bipolar technology

A monolithic microwave frequency divider IC with an operating range of 1.4?5.3 GHz was developed and fabricated in a standard bipolar technology. The circuit operates on the principle of `regenerative frequency division?. Compared to the most popular divider concepts based on a master-slave D-flip-flop, an almost twice as high input frequency can be divided, provided that the same technology is used. A further advantage is the low power consumption.     

Low temperature and strain rate dependence of fracture stress and fracture toughness on thin Fe40Ni40B20 amorphous ribbon

The fracture stress and the critical stress intensity factor of the Fe₄₀Ni₄₀B₂₀ amorphous metallic ribbons 20 μm thick were measured in the temperature range 4.2–300 K and at deformation rates from 3.3×10⁻⁶ to 1.25×10⁻³ m⁻¹ with the aim to obtain more information on the condition for the onset and development of the inhomogeneous plastic deformation and fracture.     

Simple approach to analysis of switched-capacitor circuits with nonideal op-amps

A possible method for the simulation of nonideal op-amps with a finite gain and bandwidth by means of an equivalent SC circuit, containing ideal components, is presented. The approach is extended by the case of an op-amp with non-switched input SC building blocks.     

Copper(II) removal from aqueous solutions by fly ash

The removal of Cu(II) by adsorption on fly ash has been found to be concentration, pH and temperature dependent. The kinetics of adsorption indicates the process to be diffusion controlled. The Langmuir constants have been calculated at different temperatures, and the adsorption has been found to be endothermic (ΔH = 15.652 kcal mol^?1). The maximum removal is observed at pH 8.0, and variation in adsorption with pH has been explained on the basis of surface ionisation and complexation.     

A 4.5-GHz 130-nm 32-KB L0 cache with a leakage-tolerant self reverse-bias bitline scheme

This paper describes a 32-KB two-read, one-write ported L0 cache for 4.5-GHz operation in 1.2-V 130-nm dual-V/sub TH/ CMOS technology. The local bitline uses a leakage-tolerant self reverse-bias (SRB) scheme with nMOS source-follower pullup access transistors, while preserving robust full-swing operation. Gate-source underdrive of -220 mV on the bitline read-select transistors is established without external bias voltages or gate-oxide overstress. Device-level measurements in the 130-nm technology show 72/spl times/ bitline active leakage reduction, enabling low-V/sub TH/ usage, 40% bitline keeper downsizing, and 16 bitcells/bitline. 11% faster read delay and 2/spl times/ higher dc noise robustness are achieved compared with high-performance dual-V/sub TH/ bitline scheme. Sustained performance and robustness benefits of the SRB technique against conventional dynamic bitline with scaling to 100- and 70-nm technology is also presented.     

On certain classes of exact solutions of Einstein equations for rotating fields in conventional and nonconventional form

Using the symmetry reduction approach we have herein examined, under continuous groups of transformations, the invariance of Einstein exterior equations for stationary axisymmetric and rotating case, in conventional and nonconventional forms, that is a coupled system of nonlinear partial differential equations of second order. More specifically, the said technique yields the invariant transformation that reduces the given system of partial differential equations to a system of nonlinear ordinary differential equations (nlodes) which, in the case of conventional form, is reduced to a single nlode of second order. The first integral of the resulting nlode has been obtained via invariant-variational principle and Noether’s theorem and involves an integration constant. Depending upon the choice of the arbitrary constant two different forms of the exact solutions are indicated. The generalized forms of Weyl and Schwarzschild solutions for the case of no spin have also been deduced as particular cases. Investigation of nonconventional form of Einstein exterior equations has not only led to the recovery of solutions obtained through conventional form but it also yields physically important asymptotically flat solutions. In a particular case, a single third order nlode has been derived which evidently opens up the possibility of finding many further interesting solutions of the exterior field equations.     

Compact wideband bandpass filter

Designing wideband bandpass filters (BPF) with parallel-coupled microstrip lines requires tight coupling resulting in close separation between the lines and difficulty of fabrication. Here, it is shown that the etched slots in the ground plane of the parallel coupled lines can significantly increase the coupling. This technique has been extended to realize ultra-wideband BPFs having 3-dB fractional bandwidth greater than 100% and low insertion loss in the passband.