A Novel 2.5–3.1 GHz Wide-Band Low-Noise Amplifier in 0.18 \upmu \hbox {m} CMOS

Aiming for the simultaneous realization of constant gain, accurate input and output impedance matching and minimum noise figure (NF) over a wide frequency range, the circuit topology and detailed design of wide broadband low noise amplifier (LNA) are presented in this paper. A novel 2.5–3.1 GHz wide-band LNA with unique characteristics has been presented. Its design and layout are done by TSMC 0.18  \(\upmu \hbox {m}\) technology. Common gate stage has been used to improve input matching. In order to enhance output matching and reduce the noise as well, a buffer stage is utilized. Mid-stages which tend to improve the gain and reverse isolation are exploited. The proposed LNA achieves a power gain of 15.9 dB, a NF of 3.5 dB with an input return loss less than \(-\) 11.6, output return loss of \(-\) 19.2 to \(-\) 19 and reverse isolation of \(-\) 38 dB. The LNA consumes 54.6 mW under a supply voltage of 2 V while having some acceptable characteristics.     

Finite element analysis of deformation and fracture of an exploded gas cylinder

This paper presents the finite element simulations of deformation and fracture of a gas cylinder which catastrophically failed as a result of an accidental explosion. The results of a previous detailed investigation of this incident indicated that detonation of a low-pressure oxygen-rich mixture of hydrogen and oxygen was the cause of the cylinder failure. In the current study, the finite element method was used to provide a more realistic modeling of geometry, material behavior, and boundary conditions of the cylinder. The overall transient dynamic response of the cylinder to gaseous detonation loading was studied using the ANSYS/LS-DYNA V10 package and the crack growth simulations were performed using the WARP3D-R15 research code. The crack growth analyses were performed using interface cohesive elements. The finite element results were validated using analytical solutions and data collected from the remains of the cylinder. The simulations clearly showed that the stresses caused by the assumed loading profile were indeed capable of creating local ruptures at the actual crack initiation sites. It was also shown that the self-similar growth of the initial axial crack in the main body of the cylinder was a fatigue-type incremental growth governed by the structural waves. The subsequent cyclic bulging of the crack flaps and the resultant crack curving and branching were also simulated.     

Recycling of aluminium alloy turning scrap via cold pressing and melting with salt flux

Among the various steps of aluminium production from liquid metal, a lot of scrap is generated due to machining operations. Therefore, recycling of aluminium scrap is an interesting subject because of the broad applications of this metal and low efficiency of processes used to recycle metal scrap. In this paper, the recyclability of aluminium alloy AA 336 turnings with different cold compacting pressures and a protective salt flux (NaCl–KCl–KF) has been experimentally studied. Various categories of compacted samples were melted at 750 °C in molten aluminium alloy AA 336 and also in the protective salt flux to recover aluminium alloy. In order to understand the amount of recycling of different samples, weight loss measurement was applied. From recyclability stand point it is shown that using protective salt flux is the best route, from the point of view of recyclability. Mechanical properties and chemical analysis of samples were approximately the same as the primary material produced by conventional casting process.     

Computer simulation of the effect of post annealing parameters on the microstructure inhomogeneity of the non-uniformly deformed copper

A computer simulation on the basis of the Finite Element Method and Monte Carlo Model is developed to simulate the microstructure of the non-uniformly deformed copper workpiece after annealing. Using the computer simulation, the effects of annealing time and temperature on the microstructure inhomogeneity of the workpiece are simulated and investigated quantitatively, by defining an Inhomogeneity Factor, to design an annealing program for reducing the microstructure inhomogeneity. The results show that with increasing the parameters of annealing time and temperature, the inhomogeneity is decreased when one of the parameters is constant. Also, at high annealing temperature, the annealing time changes the inhomogeneity slowly compared with which occurs at low annealing temperature. The simulation results agree well with the experimental values.     

EBIC-guidelines for management of severe head injury in adults. European Brain Injury Consortium

Guidelines for the management of severe head injury in adults as evolved by the European Brain Injury Consortium are presented and discussed. The importance of preventing and treating secondary insults is emphasized and the principles on which treatment is based are reviewed. Guidelines presented are of a pragmatic nature, based on consensus and expert opinion, covering the treatment from accident site to intensive care unit. Specific aspects pertaining to the conduct of clinical trials in head injury are highlighted. The adopted approach is further discussed in relation to other approaches to the development of guidelines, such as evidence based analysis.     

An efficient and regioselective thiocyanation of aromatic and heteroaromatic compounds using cross-linked poly (4-vinylpyridine)-supported thiocyanate as a versatile reagent and potassium peroxydisulfate as a strong oxidizing agent

A green and regioselective thiocyanation of aromatic and heteroaromatic compounds has been achieved via a simple protocol using cross-linked poly (4-vinylpyridine)-supported thiocyanate ion, [P₄-VP]SCN, as a versatile polymeric reagent and potassium persulfate as a strong oxidizing agent, under heterogeneous conditions.

Various indoles, phenol and aniline derivatives, and pyrroles were transformed into their corresponding aryl thiocyanates in high to excellent yields. This procedure offers advantages such as short reaction time, simple reaction work-up, and the polymeric reagents can be regenerated and reused for several times without significant loss of their activity.     

Synthesis of aluminium nanoparticles by arc evaporation of an aluminium cathode surface

Aluminium nanoparticles (Al Nps) are synthesized using arc discharge method by applying direct current between aluminium electrodes in liquid environment without any use of vacuum equipment, heat exchangers, high temperatures furnaces and inert gases. After synthesis of Al Nps, in situ coating process on the nanoparticles was performed immediately. The effects of media on the yield and morphology of aluminium nanoparticles were investigated. Analysis result of the samples indicated that particle size was less than 30 nm, when 120 A/cm² arc current was used. In addition, coating agent can affect arc velocity, arc stability, morphology and composition of the nanoparticles. Resultant nanoparticles were identified using X-ray powder diffraction (XRD), also their surface morphology was studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) and finally the accuracy of coating was assessed with infrared (IR) spectroscopy.     

Characterization of Al2O3 thin films fabricated through atomic layer deposition on polymeric substrates

This paper reports on the fabrication of good quality Al₂O₃ thin films on flexible substrates including polyethylene naphthalate (PEN), polyethylene terephthalate (PET) and Polyamide at different temperatures down to 50 °C under very short water purging steps of 10 s. Al₂O₃ films with appreciable growth rates having good morphological, chemical, electrical and optical characteristics have been produced. Growth rates of 1.16, 1.14 and 1.15 Å/cycle have been observed at 50 °C for PET, PEN and polyamide substrates respectively. The surface morphology has been improved with the increase in deposition temperature. Low average arithmetic roughness of 0.88 and 0.78 nm have been recorded for the Al₂O₃ films deposited at 150 °C on PEN and polyamide respectively. The XPS analysis confirmed the fabrication of Al₂O₃ films without any carbon contamination and Al 2p, Al 2s and O 1s peaks were appeared at binding energies of 74, 119 and 531 eV, respectively. Excellent insulating properties were observed for the Al₂O₃ films and optical transmittance of more than 85 % was recorded in the visible region. The experimental results suggest that polymeric materials are excellent candidates to be used as substrates in the fabrication of Al₂O₃ thin films through atomic layer deposition.     

The Electrochemical Behavior of Au/AuNPs/PNA/ZnSe-QD/ACA Electrode Towards CySH Oxidation

Nano-Micro Letters - This work describes the electrochemical behavior of azodicarboxamide (ACA) film immobilized on the surface of penicillamine (PNA)/ZnSe-quantum dot (ZnSe-QD) gold nanoparticle...