Assessment and validation of evapotranspiration using SEBAL algorithm and Lysimeter data of IARI agricultural farm,India

Evapotranspiration (ET) is a vital process in land surface atmosphere research. In this study, Surface Energy Balance Algorithm for Land (SEBAL) for the assessment of ET (for 23 December 2010, 8 January 2011, 24 January 2011, 9 February 2011, 25 February 2011, 29 March 2011 and 14 April 2011) from LANDSAT7-ETM+ and validation with Lysimeter data set is illustrated. It is based on the evaporative fraction concept, and it has been applied to LANDSAT7-ETM + (30 m resolution) data acquired over the Indian Agricultural Research Institute’s agricultural farm land. The ET from SEBAL was compared with Lysimeter ET using four statistical tests (root-mean-square error (RMSE), relative root-mean-square error (R-RMSE), mean absolute error (MAE), and normalized root-mean square error (NRMSE)), and each test showed a good correlation between the predicted and observed ET values. Results from this study revealed that the RMSE of crop-growing period was 0.51 mm d^?1 for ET_SEBAL, i.e. ET_SEBAL having good accuracy with respect to observed ET_Lysimeter. Results were also validated using R-RMSE test, which also proved that ET_SEBAL data are having good accuracy with respect to observed ET_Lysimeter as R-RMSE of crop-growing period is 0.19 mm d^?1. MAE (0.19), NRMSE (0.21) and r² (0.91) tests indicated that model prediction is significant, and model can be effectively used for the estimation of ET from SEBAL as input of remote sensing data sets. Finally, the SEBAL has been useful for remote agricultural land where ground-based data (Lysimeter data) are not available for daily ET (ET_24 h) estimation. The temporal study of the ET_24 h values analysed has revealed that the highest ET_24 h values are owing to the higher development (high greenness) of crops, whereas the lower values are related to the lower development (low greenness) or null crop.     

Insights on social learning and collaborative action plan development for disaster risk reduction: practicing Yonmenkaigi System Method (YSM) in flood-prone Mumbai

Natural Hazards - Recent decades have seen an increasing recognition and consensus among researchers and planners in disaster management in the need to foster social learning...     

Formation of cyanoallene （buta-2, 3-dienenitrile） in theinterstellar medium： a quantum chemical and spectroscopicstudy

The interstellar medium, filling the vast space between stars, is a rich reser-voir of molecular material ranging from simple diatomic molecules to more com-plex, astrobiologically important molecules such as vinylcyanide, methylcyanodiac-cetylene, cyanoaUene, etc. Interstellar molecular cyanoallene is one of the most stableisomers of methylcynoacetylene. An attempt has been made to explore the possibilityof forming cyanoallene in interstellar space by radical-radical and radical-moleculeinteraction schemes in the gaseous phase. The formation of cyanoallene starting fromsome simple, neutral interstellar molecules and radicals has been studied using densityfunctional theory. The reaction energies and structures of the reactants and productsshow that the formation of cyanoallene is possible in the gaseous phase. Both of theconsidered reaction paths are totally exothermic and barrierless, thus giving rise to ahigh probability of occurrence. Rate constants for each step in the formation processof cyanoallene in both the reaction paths are estimated. A full vibrational analysishas been attempted for cyanoallene in the harmonic and anharmonic approximations.Anharmonic spectroscopic parameters such as rotational constants, rotation-vibrationcoupling constants and centrifugal distortion constants have been calculated.     

Interacting system NGC 7805/6 (Arp 112) and its tidal dwarf galaxy candidate

We present results from our Giant Metrewave Radio Telescope(GMRT)HⅠ,Himalayan Chandra Telescope(HCT)Hα,1 m Sampurnanand Telescope(ST)and 1.3 m Devasthal Fast Optical Telescope(DFOT)deep optical observations of the NGC 7805/6(Arp 112)system to test KUG 2359+311’s tidal dwarf galaxy(TDG)candidacy and explore the properties of the interacting system.Our GMRT HⅠmap shows no HⅠdetection associated with KUG 2359+311,nor any HⅠtail or bridge-like structure connecting KUG 2359+311 to the NGC 7805/6 system.Our HCT Hαimage,on the other hand,displays strong detections in KUG 2359+311,with net SFR0.035±0.009 M_⊙yr^-1.The Hαdata constrain the redshift of KUG 2359+311 to 0.00≤z≤0.043,compared to the redshift of NGC 7806 of0.015.TDGs detected to date have all been HⅠrich,and displayed HⅠ,ionised gas and stellar tidal debris trails(bridges or tails)linking them to their parent systems.However,neither our HⅠdata nor our optical imaging,while three magnitudes deeper than SDSS,reveals a tidal trail connecting KUG 2359+311 to NGC 7805/6.Lack of HⅠ,presence of an old stellar population,ongoing star formation and reasonably high SFR compared to normal dwarf galaxies suggest that KUG 2359+311 may not be an Arp 112 TDG.It is most likely a case of a regular gas-rich dwarf galaxy undergoing a morphological transformation after having lost its entire gas content to an interaction with the Arp 112 system.Redshift and metallicity from future spectroscopic observations of KUG 2359+311 would help clarify the nature of this enigmatic structure.     

AstroSat observation of GX 5–1: spectral and timing evolution

We report on the first analysis of an AstroSat observation of the Z-source GX 5–1 on 2017 February 26-27. The hardness-intensity plot reveals that the source traced out the horizontal and normal branches. The 0.8-20 keV spectra from simultaneous SXT and LAXPC data at different locations of the hardness-intensity plot can be described well by disk emission and a thermal Comptonized component. The ratio of the disk flux to the total flux, i.e., the disk flux ratio, increases monotonically along the horizontal branch to the normal one. Thus, the difference between the normal and horizontal branches is that in the normal branch, the disk dominates the flux while in the horizontal one it is the Comptonized component which dominates. The disk flux scales with the inner disk temperature as T_(in)~(5.5 ) and not as T_(in)~4 , suggesting that either the inner radius changes dramatically or that the disk is irradiated by the thermal component changing its hardness factor. The power spectra reveal a quasi-periodic oscillation(QPO) whose frequency changes from ~30 Hz to 50 Hz. The frequency is found to correlate well with the disk flux ratio. In the 3-20 keV LAXPC band, the r.m.s. of the QPO increases with energy(r.m.s. ∝ E~(0.8)), while the harder X-rays seem to lag the soft ones with a time-delay of milliseconds. The results suggest that the spectral properties of the source are characterized by the disk flux ratio and that the QPO has its origin in the corona producing the thermal Comptonized component.     

Deformation analysis of sands in cubical and hollow cylinder devices

For discrete materials like sands, the continuum field variables, stress and strain, are defined in terms of micro-level quantities by considering the deformation mechanism of granular soils from a microscopic point of view. Under the application of load, soil is considered to deform due to the movement relative to each other of clusters of particles. Based on this deformation mechanism, the kinematics of soils are developed and a strain tensor for granular soils, in terms of local displacements and geometric measures, is introduced. A local constitutive law relating local displacements and local tractions is defined. Using the local constitutive law, the relationships between stress and strain for the media are developed. The developed model incorporates the influence of strain hardening and material anisotropy on the deformation behaviour of the media. Comparisons of the model predictions and experimental results from tests conducted in cubical and hollow cylinder devices are presented.     

Hydrodynamical winds from two-temperature plasma in X-ray binaries

Hydrodynamical winds from a spherical two-temperature plasma surrounding a compact object are constructed. The mass-loss rate is computed as a function of electron temperature, optical depth and luminosity of the sphere, the values of which can be constrained by the fitting of the spectral energy distributions for known X-ray binary systems. The sensitive dependence of the mass-loss rate with these parameters leads to the identification of two distinct regions in the parameter space separating wind-dominated from non-wind-dominated systems. A critical optical depth ( τ _c) is defined as a function of luminosity and electron temperature, which differentiates these two regions. Systems with optical depths significantly smaller than τ _c are wind-dominated.
The results are applied to black hole candidate X-ray binary systems in the hard spectral state (Cyg X-1, GX 339−4 and Nova Muscae), and it is found that the inferred optical depth ( τ ) is similar to τ _c, suggesting that they are wind-regulated systems. On the other hand, for X-ray binary systems containing a neutron star (e.g., Cyg X-2) τ is much larger than τ _c indicating the absence of significant hydrodynamical winds.     

The microconstituents of Godavari coals,South India

The present paper deals in detail with the coal typology, rank and correlation of some Indian coal seams. Petrological evaluation of several known coal seams reveals that there are two main seams, the King (lower) seam and Queen (upper) seam, with distinctly different characteristics. All the other seams, locally known by different names elsewhere in the field, are correlatable with either the King or Queen seams.The coals are of inferior quality because of the predominance of mixed coals types associated with dispersed mineral matter. However, some seams show characteristics which are amenable to quality improvement with suitable preparation methods. The coals appear to have been formed rapidly in a fluctuating environment (aerobic to anaerobic) under relatively cold to gradually warming conditions.     

Concentration of Utah tar sands by an ambient temperature flotation process

Physical separation of bitumen from low-grade Utah tar sand deposits containing a relatively high viscosity bitumen phase (Sunnyside and Tar Sand Triangle deposits) has been accomplished by traditional size reduction and froth flotation techniques. At appropriate experimental conditions more than 90% of the bitumen can be recovered in a concentrate, containing more than 20 wt. % bitumen, which should be a suitable feed material for subsequent hot water or thermal processing. The efficiency of bitumen recovery depends on the extent of size reduction, as well as promoter and dispersant addition. Rejection of greater than 60% of the sand at ambient temperature and ease of water removal from the concentrate make such a process strategy both energy and cost effective. The energy required to achieve effective separation by the ambient temperature process is significantly less than the energy required for the recently developed hot water process which is being evaluated in a 100-tpd pilot plant this year.The flotation behaviour of the tar sand in this ambient temperature process has been correlated with contact angle measurements and the apparent point-of-zero-charge of the bitumen. The best flotation response at pH 7.8 to 9.0 occurs when the contact angle between the air bubble and bitumen surface is a maximum, corresponding to the apparent point-of-zero-charge of the bitumen as determined by titration.