Size Effect on MRI/MFH Relaxations by a High Anisotropic CoFe2O4-Chitosan Conjugate and Imaging/Angiography Efficacy

Journal of Inorganic and Organometallic Polymers and Materials - We outlined cobalt ferrite (CFO) nanoparticles synthesized by chemical co-precipitation which we analyzed the structure by X-ray...     

Characterization of a chelating resin functionalized via azo spacer and its analytical applicability for the determination of trace metal ions in real matrices

A selective flame atomic absorption spectrometric method has been developed for the determination of trace amount of metal ions after preconcentration on salicylic acid (SA) loaded Amberlite XAD‐4 resin (AXAD‐4) at suitable pH. The chelating resin AXAD‐4‐SA was characterized based on FTIR, thermal and chemical stability, and hydrogen ion capacity. The sorption capacity was found to be 245.0, 156.2, 155.0, 145.0, 125.0, 122.5, and 70 μmol g^?1 for Cu(II), Cr(III), Zn(II), Cd(II), Mn(II), Ni(II), and Co(II), respectively with t_1/2 <15 min. All the metals could be eluted by 5 mL of 4 mol L^?1 HCl/HNO₃ resulting in high preconcentration factor of 200–360 up to a low preconcentration limit of 5.5–10 μg L^?1. The accuracy and precision of the developed method was checked by analyzing standard reference materials. The experimental values were not statistically significant from the certified values with <5% RSD. The detection limits were found to be 0.42, 0.57, 0.63, 0.77, 0.94, 0.96, and 1.41 μg L^?1, respectively. The analytical utility of the AXAD‐4‐SA for preconcentration and determination of metal ions was explored by analyzing river, canal, sewage, and tap water by direct as well as standard addition method. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

ORGANIC FACIES VARIATIONS AND HYDROCARBON GENERATION POTENTIAL OF PERMIAN GONDWANA GROUP COALS AND ASSOCIATED SEDIMENTS,BARAPUKURIA AND DIGHIPARA BASINS,NW BANGLADESH

In the Barapukuria and Dighipara coal basins, NW Bangladesh, the Basement Complex is overlain by the coal‐bearing Permian Gondwana Group. In the present study, 36 core samples collected from five boreholes in these two basins were analysed using organic geochemical and organic petrological methods. Based on the results of biomarker analyses (TIC, m/z 191 and m/z 217 fragmentograms) and maceral composition (proportions of vitrinite, liptinite, inertinite), three organic facies were identified: coals, carbargillites and mudstones. Together with other evidence, cross‐plots of HI versus T_max and Pr/nC₁₇ versus Ph/nC₁₈ indicate that the coals, as expected, were dominated by terrestrial organic matter (OM). The carbargillites contained a mixture of terrestrial and probable Type II aquatic OM, and the mudstones contained mostly terrestrial OM. Accordingly the coals, carbargillites and mudstones are interpreted to have been deposited in swamp‐dominated environments in a delta‐plain setting which was subject, in the case of carbargillites, to periodic flooding. Suboxic conditions were indicated by very high Pr/Ph ratios and a high content of inertinite macerals. All the samples analysed were immature or early mature for hydrocarbon generation, as indicated by mean vitrinite reflectance (%R_o) of 0.60–0.81%, Rock‐Eval T_max of 430–439°C, and biomarker ratios (hopane C₃₂ 22S/(22S+22R)) of 0.57–0.60. Carbargillites showed potential for both liquid and gaseous hydrocarbon generation; coals were mainly gas‐prone with minor liquid hydrocarbon potential; and mudstones were dominantly gas‐prone. The oil‐prone nature of the samples was attributed to the presence of resinite, cutinite, bituminite and fluorescent vitrinite. The presence of exsudatinite within crack networks, solid bitumen and oil droplets as well as bituminite at early oil‐window maturities suggests that the organic matter may have expelled some hydrocarbons.     

Comparative analysis of AlGaN/GaN high electron mobility transistor with sapphire and 4H-SiC substrate

Microsystem Technologies - This paper aims to characterize two high electron mobility transistors analyzed with sapphire and 4H-SiC substrate. Comparison of the two structures are carried out in...     

Characterization of single-ended 9T SRAM cell

We present a circuit-level technique of designing a lower write-power along with variability-resistant 9-MOFTET static random-access memory cell. Our proposed bitcell exhibits lower write-power consumption owing to reduction of activity factor and breakup of feedback path between the cross-coupled inverters during write operation. It exhibits higher read static noise margin (by 3.09 ×) compared with standard 6T SRAM cell @ minimum-area. LP9T shows higher static margin for write operation (by 41%) compared with 8T (S6T) @ iso-area (minimum-area). These improvements are achieved due to breakup of feedback path during the process of writing a bit on to the storage node. The paper investigates in detail the influence of variation in process related parameters, environmental parameters such as supply voltage and temperature on most of the important design parameters of the bitcell and compares the obtained simulation results with conventional 6-MOSFET (6T) and 8-MOSFET (8T) bitcells. It demonstrates its invariableness by showing 1.5 × tighter disperse in read time variability with a cost of 1.41 × higher read time compared with S6T @ minimum-area. It also exhibits 39% narrower disperse in read time variability in comparison to 8T @ iso-area. It draws lower power (2.06 ×) from supply voltage while flipping of stored data during write mode compared with standard 8T SRAM cell @ iso-area. It also compares key design metrics of LP9T with those of few other 9T SRAM cells found in the literature. This work also realizes the proposed design using CNFET. The CNFET-based design outperforms its CMOS counterpart in all respect.

     

Compact design of an MTJ-based non-volatile CAM cell with read/write operations

Microsystem Technologies - This paper presents a novel design of a magnetic tunnel junction (MTJ) based content addressable memory (CAM) cell with low power dissipation and small-time delay....     

Torque–speed relationship in a concrete rheometer with vane geometry

Derivation of mathematical relationship between torque and speed during shearing in concrete rheometer with vane geometry has been presented in this paper. Resistance offered by concrete below and above the vane as well as effect of concrete resistance from the annulus were taken into consideration to represent actual flow condition of concrete during shearing. An expression for total shear stress has been derived from where shear stress versus torque and shear strain rate versus rotational frequency relationships have been established for the vane geometry of a concrete rheometer.     

A 2.4 GHz double balanced downconversion mixer with improved conversion gain in 180-nm technology

In this paper a 2.4-GHz non-return to zero (abbreviated as NRZ) active downconversion mixer for transceiver system is demonstrated. It features with the double- balanced topology, NRZ mechanism, an effecting biasing technique and a current mirror technique are used to achieve the requirements. Downconversion mixer is realized on 180 nm CMOS technology. Despite of trade-off between conversion gain and linearity we can achieve very high conversion gain with moderate linearity. Simulations using cadence tool exhibits a conversion gain of 24.61 dB, a third order intercept point of 6.17 dB, a 1-dB compression point of − 5.86 dB and a second order intercept point of + 87.66 dB at 1.8 V supply.