Development of real-time reference evapotranspiration at the regional scale using satellite-based observations

Real-time data of reference evapotranspiration (ET₀) at different space-time scales are essential to regional agricultural drought assessment, water accounting at the watershed to basin scale, and provide irrigation advisory to farmers. Here, we present a data-fusion approach that integrates satellite-based insolation product (8 km) from an Indian geostationary satellite (Kalpana-1) sensor (VHRR; Very High Resolution Radiometer) and high-resolution (~ 5 km) short-range weather forecast into an FAO56 model based on the classical Penman–Monteith (P-M) formulation. Five year (2009–2013) mean monthly estimates from the daily ET₀ product over the Indian landmass were found to vary between 10 and 350 mm. It increased from January to May (70–350 mm), followed by a decrease to reach the lowest in November (10–140 mm), thus typically showing unimodal distribution. The comparison of daily space-based and station-based estimates (at six ground stations) produced a root mean square deviation (RMSD) ranging from 21% to 38% for 977 paired data sets with the correlation coefficient (r) varying from 0.32 to 0.82. The error was reduced from 25% to 10% with an increase in ‘r’ from 0.43 to 0.98 for daily to 10 day summation period. Spatial grid-to-grid comparison of monthly ET₀ estimates with Global Data Assimilation System (GDAS) potential evapotranspiration (PET) showed RMSD within a range of 1.4–18.4% for most of the months, except for two. Further ET₀ analysis over normal and drought years showed that it could be used for comprehensive drought assessment with other existing indicators.     

Effect of toothless stator design on the dynamic performancecharacteristics of high speed permanent magnet generator-load systems

The results of a study on the effect of toothless stator design on the dynamic performance characteristics of high speed permanent magnet generator-load systems are presented. This study is based on the use of magnetic field solutions and state space models which account for saturation due to magnetic material nonlinearities and space harmonics due to machine geometry. Two particular stator designs, a toothless stator and a conventional type stator (with iron teeth), are considered in this study when feeding AC and DC rectified loads. Based on this study, it is demonstrated that the toothless design for this class of PM generators could result in lower levels of harmonics in the various machine voltages and currents waveforms as well as the power delivered to the loads. In addition, some design modifications are discussed to boost the output power level of the toothless machine which are inherently lower than the conventional machine due to the larger effective airgap that exists in the toothless design     

Liver damage preferentially results from CD8(+) T cells triggered by high affinity peptide antigens

Little is understood of the anatomical fate of activated T lymphocytes and the consequences they have on the tissues into which they migrate. Previous work has suggested that damaged lymphocytes migrate to the liver. This study compares class I versus class II major histocompatibility complex (MHC)-restricted ovalbumin-specific T cell antigen receptor (TCR) transgenic mice to demonstrate that after in vivo activation with antigen the emergence of CD4(-)CD8(-)B220(+) T cells occurs more frequently from a CD8(+) precursor than from CD4(+) T cells. Furthermore, this change in phenotype is conferred only by the high affinity native peptide antigen and not by lower affinity peptide variants. After activation of CD8(+) cells with only the high affinity peptide, there is also a dramatically increased number of liver lymphocytes with accompanying extensive hepatocyte damage and elevation of serum aspartate transaminase. This was not observed in mice bearing a class II MHC-restricted TCR. The findings show that CD4(-)CD8(-)B220(+) T cells preferentially derive from a CD8(+) precursor after a high intensity TCR signal. After activation, T cells can migrate to the liver and induce hepatocyte damage, and thereby serve as a model of autoimmune hepatitis.     

Photothermal lensing detection: theory and experiment

Photothermal lensing signal shapes are experimentally investigated and compared with those predicted theoretically in our earlier paper. The investigation included flowing and stationary media and pulsed and cw excitations. Good qualitative agreement between theory and experiment is found. Since the lensing signal is almost always accompanied by a deflection signal, the influence of the deflection signal on the detection of lensing signal is investigated. For a perfectly aligned detection geometry the influence of the deflection signal on the lensing signal is negligible, but in the presence of misalignments a significant amount of deflection signal could be superimposed on the lensing signal. The effect of lensing on the deflection signal is also been considered. The effect of the finite size of the probe beam on the lensing signals is also investigated.     

Enhanced near-infrared periocular recognition through collaborative rendering of hand crafted and deep features

Periocular recognition leverage from larger feature region and lesser user cooperation, when compared against the traditional iris recognition. Moreover, in the current scenario of Covid-19, where majority of people cover their faces with masks, potential of recognizing faces gets reduced by a large extent, calling for wide applicability of periocular recognition. In view of these facts, this paper targets towards enhanced representation of near-infrared periocular images, by combined use of hand-crafted and deep features. The hand-crafted features are extracted through partitioning of periocular image followed by obtaining the local statistical properties pertaining to each partition. Whereas, deep features are extracted through the popular convolutional neural network (CNN) ResNet-101 model. The extensive set of experiments performed with a benchmark periocular database validates the promising performance of the proposed method. Additionally, investigation of cross-spectral matching framework and comparison with state-of-the-art, reveal that combination of both types of features employed could prove to be extremely effective.

     

Insider attack mitigation in a smart metering infrastructure using reputation score and blockchain technology

International Journal of Information Security - The increasing use of smart metering infrastructure invites security threats through trusted insiders in spite of the devices’ authentication...     

Rooted-tree network for optimal non-local gate implementation

Quantum Information Processing - A general quantum network for implementing non-local control-unitary gates, between remote parties at minimal entanglement cost, is shown to be a rooted-tree...     

Characterization of some organic poly(aminiumphosphate)s

Summary Metachromatic reactions of MB and AO are studied with poly(aminium phosphate)s. The main band() at 665 m and 492 m for MB and AO are shifted to 580 m and 455 m respectively (-bands). The metachromatic values at different concentrations of poly(aminium phosphate)s are also reported. The dye association for MB with these polymer derivatives is investigated conductometrically as well. It is observed that MB can be at the most bind with the phosphate residue of polymer upto 11 molar ratio. The polymeric nature was further established by paper chromatographic technique in Terry's, Ebel's & Pfrengle's solvents.     

Elimination of current non-uniformity in carbon nanotube field emitters

Activation of abnormal emitting sites in Carbon Nano Tube (CNT) field emitters and their elimination is reported. CVD grown, patterned CNT was used as cathode for field emission studies. We encountered the problem of current non-uniformity in CNT cathode. This non-uniformity was attributed to abnormally active emitting sites during voltage ramp-up. The sudden increase in current resulted in region of positive slope in F–N curve, which can’t be explained by conventional F–N theory. Also the grown CNTs can be a mixture of metallic and semi conducting nature, which may cause deviation from the conventional F–N theory. We could eliminate abnormally active sites by electric field treatment, thereby increasing current uniformity and stability. The work is underway to understand the deviation in FN curve at high fields.