A multi-sensor data-driven methodology for all-sky passive microwave inundation retrieval

We present a multi-sensor Bayesian passive microwave retrieval algorithm for flood inundation mapping at high spatial and temporal resolutions. The algorithm takes advantage of observations from multiple sensors in optical, short-infrared, and microwave bands, thereby allowing for detection and mapping of the sub-pixel fraction of inundated areas under almost all-sky conditions. The method relies on a nearest-neighbor search and a modern sparsity-promoting inversion method that make use of an a priori dataset in the form of two joint dictionaries. These dictionaries contain almost overlapping observations by the Special Sensor Microwave Imager and Sounder (SSMIS) on board the Defense Meteorological Satellite Program (DMSP) F17 satellite and the Moderate Resolution Imaging Spectroradiometer (MODIS) on board the Aqua and Terra satellites. Evaluation of the retrieval algorithm over the Mekong Delta shows that it is capable of capturing to a good degree the inundation diurnal variability due to localized convective precipitation. At longer timescales, the results demonstrate consistency with the ground-based water level observations, denoting that the method is properly capturing inundation seasonal patterns in response to regional monsoonal rain. The calculated Euclidean distance, rank-correlation, and also copula quantile analysis demonstrate a good agreement between the outputs of the algorithm and the observed water levels at monthly and daily timescales. The current inundation products are at a resolution of 12.5 km and taken twice per day, but a higher resolution (order of 5 km and every 3 h) can be achieved using the same algorithm with the dictionary populated by the Global Precipitation Mission (GPM) Microwave Imager (GMI) products.Comment: 12 pages, 9 Figure

Studies of Reaction Mechanisms in Organic Chemistry Using Radiochemical Techniques

An investigation of the mechanism of dehydrogenation of a hydroaromatic compound, 1:4,dihydronaphthalene, by a quinone, tetrachloro-1:4,benzoquinone, has been made. The reaction has been studied by kinetic measurements, spectroscopic measurements and by the determination of tritium isotope effects. The measurements were carried out at 80 C and phenetole was used as the solvent for the reaction mixture. In previous work in these types of systems second order kinetics are generally observed and the bulk of the experimental evidence suggests that the reaction proceeds by an ionic rather than a free radical mechanism. Transfer of a hydride ion has been postulated as the rate determining step. The present work does not entirely support this viewpoint; second order kinetics were only observed in the later stages of the reaction and in the initial reaction period the kinetic data suggest the mechanism is more complex than has previously been supposed. In addition, during the time over which the reaction was normally followed, i. e. 120 minutes, the amount of naphthalene formed is equivalent to approximately half of the 1:4,dihydronaphthalene consumed. The isotope effect measurements, using partially tritiated 1.4,dihydronaphthalene, have given a value of kT/k. =1.16+/-0.16. This result does not support the view that fission of the carbon-hydrogen bond is the rate-determining step, i. e. hydride ion transfer. The result is interpreted in terms of the first step in the reaction being the establishment of an equilibrium involving the formation of a charge-transfer complex and the value of k T/k greater than unity results from an inverse secondary isotope effect. The spectroscopic measurements prove the existence of charge-transfer complexes in the reaction mixture and indicate that the formation of these complexes is the initial step in the reaction. The extra consumption of 1:4,dihydronaphthalene in the reaction is ascribed to the formation of a chloro-substituted quinone in which a chlorine is replaced by monohydronaphthalene group. This byreaction would lead to the production of hydrogen chloride and the latter has been detected among the reaction products. It has been observed that significant amounts of hydrogen chloride do have a small catalytic effect on the reaction. The present work suggests that the reaction proceeds by an ionic mechanism but modifications in the earlier schemes are required. The following scheme is suggested for the reaction of the hydroaromatic compound (RH2) with the tetrachloroquinone (QCL4): RH2 + QCL4 ↔ charge-transfer complex (1) CT complex → RH+ + QCL4H- (2) RH+ + QCL4H-→ R + QCL4H2 (3) or CT complex → RHQCL3 + HCl (4) In systems where the quinone has a low redox potential, or where there is substantial steric hindrance, the formation of the charge transfer complex, step (1), can be rate determining, while with quinones of high redox potential step (1) is relatively rapid and step (2) is the rate determining step

Kinematics of Persistent Random Walkers with Distinct Modes of Motion

We study the stochastic motion of active particles that undergo spontaneous transitions between distinct modes of motion. Each mode is characterized by a speed distribution and an arbitrary (anti-)persistence. We develop an analytical framework to provide a quantitative link between the particle dynamics properties and macroscopically observable transport quantities of interest. For exponentially distributed residence times in each state, we derive analytical expressions for the initial anomalous exponent, the characteristic crossover time to the asymptotic diffusive dynamics, and the long-term diffusion constant. We also obtain exact expressions for the time evolution of the arbitrary moments of displacement -- particularly the mean square displacement -- over all time scales. Our approach enables us to disentangle the combined effects of speed, directional persistence, and switching probabilities between the states on the kinematics of particles in a wide range of multistate stochastic active/passive processes and to optimize the transport quantities of interest with respect to any of the particle dynamics properties.Comment: 8 pages, 5 figures. arXiv admin note: text overlap with arXiv:1909.0503

Study of GPCR levels in Iraqi diabetic and diabetic nephropathy

Abstract Aim of the study is to determined  G-protein coupled receptor levels in diabetic and diabetic nephropathy patients and compare the results with control group. Study also, aimed   to find relationship  of GPCR with HbA1c , cholesterol and Triglyceride  in these patients ,in order to  that GPCR could be used as a marker combat diabetes and its complication . One hundred fifty subjects were involved  in this study that divided into three groups as follows:- Control group (G1) consists of 50 healthy individuals. Diabetic group (G2) consists of 50 patients and diabetic Nephropathy group (G3) consists of 50 patients . levels of HbA1c % , urea , createnine , albumin , TC, TG, HDL-c, LDL-c , VLDL-c and GPCR were determined in all subjects. Conclusion could be drawn from study that the difference between GPCR levels among  groups indicate GPCR may be used as a marker in development of diabetic nephropathy as well as their  are a significant relation for GPCR with TC and TG . Keywords: GPCR , diabetic and diabetic nephropath

Characteristics of Vehicular Traffic Flow at a Roundabout

We construct a stochastic cellular automata model for the description of vehicular traffic at a roundabout designed at the intersection of two perpendicular streets. The vehicular traffic is controlled by a self-organized scheme in which traffic lights are absent. This controlling method incorporates a yield-at-entry strategy for the approaching vehicles to the circulating traffic flow in the roundabout. Vehicular dynamics is simulated within the framework of the probabilistic cellular automata and the delay experienced by the traffic at each individual street is evaluated for specified time intervals. We discuss the impact of the geometrical properties of the roundabout on the total delay. We compare our results with traffic-light signalisation schemes, and obtain the critical traffic volume over which the intersection is optimally controlled through traffic light signalisation schemes.Comment: 10 pages, 17 eps figures. arXiv admin note: text overlap with arXiv:cond-mat/040107