Enhanced SO2 concentrations observed over northern India: role of long-range transport

The combustion of fossil fuels (coal and petroleum products) constitutes a source of continuous release of anthropogenic SO₂ into the atmosphere. Furthermore, natural sources such as volcanoes can inject large amounts of SO₂ directly into the troposphere and sometimes even into the stratosphere. These event-based volcanic eruptions provide solitary opportunities to study the transport and transformation of atmospheric constituents. In this study, we present an episode of high SO₂ concentration over northern India as a result of long-range transport from Africa using multiple satellite observations. Monthly averaged column SO₂ values over the Indo-Gangetic Plain (IGP) were observed in the range of 0.6–0.9 Dobson units (DU) during November 2008 using observations from the Ozone Monitoring Instrument (OMI). These concentrations were conspicuously higher than the background concentrations (<0.3 DU) observed during 2005–2010 over this region. The columnar SO₂ loadings were highest on 6 November over most of the IGP region and even exceeded 6 DU, a factor of 10–20 higher than background levels in some places. These enhanced SO₂ levels were not reciprocated in satellite-derived NO₂ or CO columns, indicating transport from a non-anthropogenic SO₂ source. As most of the local aerosols over the IGP region occur below 3 km, a well-separated layer at 4–5 km was observed from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite. Wind fields and back-trajectory analysis revealed a strong flow originating from the Dalaffilla volcanic eruption in Ethiopia during 4–6 November 2008. Although volcanic SO₂ plumes have been extensively studied over many parts of Asia, Europe, and the USA, analysis of such events for the IGP region is being reported for the first time in this study.     

Hole mobility enhancement in strained-Si p-MOSFETs under high vertical field

The growth of a high quality, step-graded lattice-relaxed SiGe buffer layer on a Si(100) substrate is investigated. p-MOSFETs were fabricated on strained-Si grown on top of the above layer. Carrier confinement at the type-II strained-Si/SiGe buffer interface is observed clearly from the device transconductance and C-V measurements. At high vertical field, compared to bulk silicon, the channel mobility of the strained-Si device with x=0.18 is found to be about 40% and 200% higher at 300 K and 77 K respectively. Measurements on transconductance enhancement are also reported. Data at 77 K provide evidence of two channels and a large enhancement of mobility at high transverse field.     

A new family of synthetic diterpenes that regulates cytokine synthesis by inhibiting IkappaBalpha phosphorylation

The synthesis and the biological evaluation of a new family diterpenes are presented. The synthetic studies were inspired by the structural framework of acanthoic acid (1) and yielded a family of compounds that were evaluated as anti-inflammatory agents. Among them, compounds 2, 10, 12, and 16 exhibited a very low nonspecific cytotoxicity and inhibited the synthesis of TNF-alpha with greater than 65 % efficacy at low micromolar concentrations. Cytokine-specificity studies revealed that these compounds also inhibited the synthesis of the proinflammatory cytokines IL-1beta and IL-6, while inhibition of IL-1ra and IL-8 synthesis was marginal and only occurred at high concentrations. Further studies, through EMSA and Western blot analyses, indicated that these compounds decreased the extent of phosphorylation of IkappaBalpha; this suggests that they exert their anti-inflammatory profile by inhibiting NF-kappaB-mediated cytokine synthesis. These findings imply that these diterpenes represent promising leads for the development of novel anti-inflammatory agents.     

Negative bias temperature instability in strain-engineered p-MOSFETs: a simulation study

Negative Bias Temperature Instability (NBTI) in p-MOSFETs is a serious reliability concern for digital and analog CMOS circuit applications. Strain in the channel region affects negative bias temperature instabilities, low frequency noise, radiation hardness, gate oxide quality and hot carrier performance. The understanding of these phenomena in strain-engineered p-MOSFETs from fundamental physics is essential. In this paper, technology CAD (TCAD) has been used to study the effects of strain on the negative bias temperature instabilities in p-MOSFETs. A quasi two dimensional (quasi-2D) physics-based Coulomb scattering mobility model for strained-Si has been developed and implemented in Synopsys Sentaurus Device tool for device simulation to understand NBTI in strain-engineered p-MOSFETs.     

Review and comparative evaluation of symbolic dynamic filtering for detection of anomaly patterns

Symbolic dynamic filtering (SDF) has been recently reported in literature as a pattern recognition tool for early detection of anomalies (i.e., deviations from the nominal behavior) in complex dynamical systems. This paper presents a review of SDF and its performance evaluation relative to other classes of pattern recognition tools, such as Bayesian Filters and Artificial Neural Networks, from the perspectives of: (i) anomaly detection capability, (ii) decision making for failure mitigation and (iii) computational efficiency. The evaluation is based on analysis of time series data generated from a nonlinear active electronic system. This work has been supported in part by the U.S. Army Research Laboratory and the U.S. Army Research Office under Grant No. W911NF-07-1-0376, by the U.S. Office of Naval Research under Grant No. N00014-08-1-380, and by NASA under Cooperative Agreement No. NNX07AK49A.     

CMOS performance enhancement in Hybrid Orientation Technologies

Possible MOSFET performance enhancement by combining the hybrid-orientation technology (HOT) and process-induced local strain engineering is predicted for sub-45-nm CMOS technology nodes via technology CAD (TCAD) simulation. Mobility enhancements are modeled for both the hybrid orientation and process-induced local strain in CMOS technologies and are used in simulation. RF performance is investigated in detail and peak cutoff frequency, f _T of 524 GHz for n-MOSFETs and 239 GHz for p-MOSFETs are predicted from simulation.     

Identification of intracranial haemorrhage (ICH) using ResNet with data augmentation using CycleGAN and ICH segmentation using SegAN

Multimedia Tools and Applications - Intracranial Haemorrhage (ICH) occurring due to any injury to the brain is a fatal condition and its timely diagnosis is critically important. In this work, we...     

A blind audio watermarking based on singular value decomposition and quantization

International Journal of Speech Technology - In this work, we have proposed a robust audio watermarking technique in which a binary image is embedded into a host audio signal for copyright...