A closed loop inductorless equalizer with a modified analysis of power comparator behaviour

Inductorless circuits are gaining advantage in radio frequency (RF) and high-speed serial link circuits due to the reduced silicon area. This paper presents an inductorless adaptive analog equalizer using an adaptive hybrid filter comprising integrated low pass and high pass filter. The equalizer, designed and fabricated in 180-nm CMOS technology, is able to adjust the high-frequency boost (HFB) and cutoff frequency of the internal filters depending on the data rate and the channel loss. The presented equalizer operates at data rates more than 4 Gbps in post-layout simulation without electrostatic discharge (ESD) and package parasitics. For the test purposes, the equalizer has been packaged in QFN 64 pin package and hence the measurement results are up to 3.125 Gbps. The measurement results show that the equalizer is able to adapt the HFB for the channel losses as high as 5 dB. Average dissipated power of the equalizer at 3.125 Gbps is 18 mW with 1.8-V supply. After reading this chapter you should be able to understand the merits of the proposed hybrid filter compared with the conventional RC filters in the adaptive equalizer using spectrum balancing technique; theoretical analysis and the impact of short channel effects on the performance of the power comparator; and test results of the adaptive equalizer using the proposed hybrid filter in the spectrum balancing technique.     

Three-dimensional neural network tracking control of a moving target by underactuated autonomous underwater vehicles

Neural Computing and Applications - This paper investigates three-dimensional target tracking control problem of underactuated autonomous underwater vehicles (AUVs) by using coordinates...     

Blind three dimensional deconvolution via convex optimization

Multidimensional Systems and Signal Processing - In this paper we discuss recovering two signals from their convolution in 3 dimensions. One of the signals is assumed to lie in a known subspace and...     

Experimental and Comparative Investigations of New Self-Expanded Steel Pile Behavior via Physical Modelling

Soil Mechanics and Foundation Engineering - Engineers have used several types of piles as the foundation system in the range of conventional or unconventional ones in onshore or offshore...     

Measurement of the uniaxial mechanical properties of healthy and atherosclerotic human coronary arteries

Atherosclerosis is a common arterial disease which alters the stiffness of arterial wall. Arterial stiffness is related to many cardiovascular diseases. In this investigation, maximum stress and strain as well as physiological and maximum elastic modulus of 22 human coronary arteries are measured. In addition, the force-displacement diagram of human coronary artery is obtained to discern the alterations between the healthy and atherosclerotic arterial wall stiffness. The age of each specimen and its effect on the elastic modulus of human coronary arteries is also considered. Twenty-two human coronary arteries, including eight atherosclerotic and fourteen healthy arteries are excised within 5 hours post-mortem. Samples are mounted on a tensile-testing machine and force is applied until breakage occurs. Elastic modulus coefficient of each specimen is calculated to compare the stiffness of healthy and atherosclerotic coronary arteries. The results show that the atherosclerotic arteries bear 44.55% more stress and 34.61% less strain compared to the healthy ones. The physiological and maximum elastic moduli of healthy arteries are 2.53 and 2.91 times higher than that of atherosclerotic arteries, respectively. The age of specimens show no correlation with the arterial wall stiffness. A combination of biomechanics and mathematics is used to characterize the mechanical properties of human coronary arteries. These results could be utilized to understand the extension and rupture mechanism of coronary arteries and has implications for interventions and surgeries, including balloon-angioplasty, bypass, and stenting.     

Mechanical performance of styrene-butadiene-rubber filled with carbon nanoparticles prepared by mechanical mixing

Reinforcement of styrene-butadiene-rubber (SBR) was investigated using two different carbon blacks (CBs) with similar particle sizes, including highly structured CB and conventional CB, as well as multi-walled carbon nanotube (MWCNT) prepared by mechanical mixing. The attempts were made to examine reinforcing mechanism of these two different classes of carbon nanoparticles. Scanning electron microscopy and electrical conductivity measurement were used to investigate morphology. Tensile, cyclic tensile and stress relaxation analyses were performed. A modified Halpin-Tsai model based on the concept of an equivalent composite particle, consisting of rubber bound, occluded rubber and nanoparticle, was proposed. It was found that properties of CB filled SBR are significantly dominated by rubber shell and occluded rubber in which molecular mobility is strictly restricted. At low strains, these rubber constituents can contribute in hydrodynamic effects, leading to higher elastic modulus. However, at higher strains, they contribute in stress hardening resulting in higher elongation at break and higher tensile strength. These elastomeric regions can also influence stress relaxation behaviors of CB filled rubber. For SBR/MWCNT, the extremely great inherent mechanical properties of nanotube along with its big aspect ratio were postulated to be responsible for the reinforcement while their interfacial interaction was not so efficient.     

Effect of carbon‐based nanoparticles on the cure characteristics and network structure of styrene–butadiene rubber vulcanizate

The network structure of styrene–butadiene rubber (SBR) in the presence of carbon black (CB) with two different structures and multi‐walled carbon nanotubes (MWCNTs) was investigated. Swelling behaviour, tensile properties at various strain rates and cure kinetics were characterized. Experimental data were analysed using the Flory–Rehner model as well as the tube model theory. It is found that the network structure of CB‐filled SBR follows a three‐phase composite model including rigid particles, semi‐rigid bound rubber and matrix rubber. This bound rubber is postulated to be critical for the mechanical and deformational properties, development of crosslinking density in matrix rubber and polymer–filler interaction. For MWCNT‐filled SBR, the bound rubber does not show a substantial contribution to the network structure and mechanical performance, and these properties are greatly dominated by the higher aspect ratio and polymer–filler interaction. Additionally it is deduced that the crosslinking density of matrix rubber increases on incorporation of the fillers compared to unfilled matrix rubber. Copyright © 2012 Society of Chemical Industry     

Morphological and mechanical properties of polyamide 6/nanodiamond composites prepared by melt mixing: effect of surface functionality of nanodiamond

Surface chemistry of as‐received nanodiamond (ND) was first tailored by dry thermal oxidation to obtain carboxylated ND (ND‐COOH) and by wet chemistry to obtain ethylenediamine‐functionalized ND (ND‐EDA). Then, the surface‐functionalized ND particles were dispersed in polyamide 6 (PA6) using the melt‐mixing method. Transmission optical and scanning electron microscopies indicated a fine dispersion at low nanodiamond concentrations, e.g. 0.25 wt%, particularly with ND‐EDA. Differential scanning calorimetry revealed that ND‐EDA favoured the α‐phase crystal and enhanced the degree of crystallinity of PA6. Experimental data indicated that ND‐EDA had considerably improved tensile properties at low concentration of 0.25 wt% compared to ND‐COOH, which was correlated to the fine dispersion and stronger and thicker interphase in the case of ND‐EDA. It was also found that the toughness of PA6 was improved on incorporation of ND‐EDA due to development of microcracking and crazing. © 2016 Society of Chemical Industry     

Crystal and morphology development in immiscible nonpolar polymer blend nanocomposite based on low-density polyethylene and linear low-density polyethylene in presence of clay and compatibilizer

In this work, polyolefin-blend/clay nanocomposites based on low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and organically modified clay (OC) were prepared by melt extrusion. Various grades of maleic anhydride (MA) grafted polyethylene (PE-g-MA) were used and examined as compatibilizers in these nanocomposites. Differential scanning calorimetry analysis showed that OC and compatibilizer affect the crystallization behavior of LDPE/LLDPE with different mechanisms. Thermodynamic calculations of wetting coefficient based on interfacial energy between OC, LD, and LL, Morphological characterization based on field emission scanning electron microscopy, X-ray diffraction, small angles X-ray scattering, and dynamic rheology measurements revealed that the compatibilizer and OC were localized at the interface of LDPE and LLDPE phases with a preferred tendency toward one phase. Results demonstrated that at a specific amount of OC, there is an optimum compatibilizer concentration to achieve nanodispersed OC and beyond that the compatibilizer causes a structural change in the polymer crystalline morphology. It was also found that the tensile property enhancement of LDPE/LLDPE/OC nanocomposites is closely related to the crystalline structure development made by incorporation of both OC and compatibilizer.     

A novel architecture for improving slew rate in FinFET-based op-amps and OTAs

A new architecture for improvement of slew rate (SR) of an op-amp or an operational transconductance amplifier (OTA) in FinFET technology is proposed. The principle of operation of the proposed architecture is based on a set of additional current sources which are switched on, only when OTA should provide a high current, usually for charge or discharge of large load capacitor. Therefore, the power overhead is less compared to conventional high SR designs. The commonly used two-stage Miller-compensated op-amp, designed and optimized in sub 45 nm FinFET technology with 1 V single supply voltage, is used as an example for demonstration of the proposed method. For the same FinFET technology and with optimal design, it is shown that the slew rate of the op-amp is significantly improved. The slew rate is improved from 273 to $5590\mathrm{V}/\mathrm{\mu }\mathrm{s}$ for an input signal with a rise time of 100 ps. The other performance measures such as gain and phase margin remain unchanged with the additional circuitry used for slew rate enhancement.