Mapping and modeling groundnut growth and productivity in rainfed areas of Tamil Nadu

A research study was conducted at Tamil Nadu Agricultural University, Coimbatore during kharif and rabi 2015 to estimate groundnut area, model growth and productivity and assess the vulnerability of groundnut to drought using remote sensing techniques. Multi temporal Sentinel 1A satellite data at VV and VH polarization with 20 m spatial resolution was acquired from May, 2015 to January, 2016 at 12 days interval and processed using MAPscape-RICE software. Continuous monitoring was done for ground truth on crop parameters in twenty monitoring sites and validation exercise was done for accuracy assessment. Input files on soil, weather and management practices were generated and crop coefficients pertaining to varieties were developed to assess growth and productivity of groundnut using DSSAT CROPGRO-Peanut model. Outputs from remote sensing and DSSAT model were assimilated to generate LAI thereby groundnut yield spatially and validated against observed yields. Being a rainfed crop, vulnerability of groundnut to drought was assessed integrating different meteorological and spectral indices viz., Standardized Precipitation Index (SPI), Normalized Difference Vegetation Index (NDVI) and Water Requirement Satisfaction Index (WRSI).Spectral dB curve of groundnut was generated using temporal multi date Sentinel 1A data. A detailed analysis of temporal signatures of groundnut showed a minimum at sowing and a peak at pod development stage and decreasing thereafter towards maturity. Groundnut crop expressed a significant temporal behaviour and large dynamic range (-11.74 to -5.31 in VV polarization and -20.04 to -13.05 in VH polarization) during its growth period. Groundnut area map was generated using maximum likelihood classifier integrating multi temporal features with a classification accuracy of 87.2 per cent and a kappa score of 0.74. The total classified groundnut area in the study districts was 88023 ha covering 17817 and 22582 ha in Salem and Namakkal districts during kharif 2015 while Villupuram and Tiruvannamalai districts accounted for 22722 and 24903 ha respectively during rabi 2015. Blockwise statistics on groundnut area during both seasons were also generated. To model growth and productivity of groundnut in DSSAT, weather and soil input files were generated using weatherman and ‘S’ build respectively besides deriving genetic coefficients for CO 6, TMV 7 and VRI 2 varieties of groundnut. Growth and development variables of groundnut were simulated using CROPGROPeanut model i.e., days to emergence (7-9 days) and anthesis (25-32 days), canopy height (63 to 70 cm), maximum LAI (1.12 to 3.07) and biomass (4176 to 9576 kg ha-1 across twenty monitoring locations spatially. The resultant pod yield was simulated to be 1796 to 3060 kg ha-1 with a harvest index of 0.28 to 0.43. On comparison of LAI between observed (2.01 to 4.05) and simulated values (1.12 to 3.07) the CROPGRO-Peanut model was found to under estimate the values with R2, RMSE and NRMSE of 0.82, 1.10 and 34 per cent. However, the model predicted the biomass of groundnut with an agreement of 89 per cent through the simulated values of 4176 to9576 kg ha-1 as against the observed biomass to 4620 to 9959 kg ha-1. The simulated pod yields of groundnut in the study area were 1796 to 3060 kg ha-1 as compared to the observed yields of 2115 to 2750 kg ha-1. The overall agreement between simulated and observed yields was 84 per cent with the average errors of 0.81, 342 kg ha-1 and 16 percent for R2, RMSE and NRMSE respectively. LAI values of groundnut, generated spatially through suitable regression models using dB from satellite images and LAI from DSSAT, ranged from 1.31 to 3.23 with R2, RMSE and NRMSE of 0.86, 0.78 and 24 per cent respectively on comparison with observed values. Remote sensing based spatial estimation resulted in groundnut pod yields of 1570 to 3102 kg ha-1 across the study districts of Salem, Namakkal, Tiruvannamalai and Villupuram. In the 20 monitoring locations, the pod yields were estimated to be 1912 to 2975 kg ha-1 as against the observed pod yields of 1450 to 2750 kg ha-1 with a fairly good agreement of 80 per cent. The vulnerability of groundnut was assessed using different drought indices viz., SPI, NDVI and WRSI. Considering SPI, out of the total groundnut area of 88023 ha, an area of 86607 ha was found to be under near normal condition based on deviation of rainfall received during cropping season from historical precipitation. Similarly NDVI, an indicator of vegetation condition during the cropping season, showed that 14272 ha of groundnut area were under stressed condition during 2015. An area of 40981 ha in Villupuram and Tiruvannamalai districts was found to be under chances of crop failure based on Water Requirement Satisfaction index (WRSI). Major groundnut areas of Salem district (14188 ha) was under medium risk zone. Considering overall vulnerability, whole district of Villupuram was adjudged as highly vulnerable to drought with regard to groundnut cultivation whereas four blocks of Salem, eight blocks of Namakkal and all the blocks of Tiruvannamalai were found to be moderately vulnerable to drought

Evaluation of turbulence/radiation effects using LES combustion simulation data

This paper describes the evaluation of turbulence/radiation effects on a swirl flame. The data obtained from a LES calculation in this case provides time-varying temperature field and species concentrations contributing to radiation fluctuations. In the radiation calculations demonstrated here, time varying data obtained from the LES calculations are post processed using the Discrete Transfer method incorporating a radiative property calculation algorithm to obtain radiation fluctuation statistics. The study provides an insight into how radiation fluxes, absorption coefficients and radiation intensities fluctuate in a highly turbulent complex practical flame. Simulation results show that temperature self correlation can be as high as 4 times and turbulence fluctuations has a very significant effect on source term calculations

On the Derivation of Vector Radiative Transfer Equation for Polarized Radiative Transport in Graded Index Media

Light transport in graded index media follows a curved trajectory determined by the Fermat's principle. Besides the effect of variation of the refractive index on the transport of radiative intensity, the curved ray trajectory will induce geometrical effects on the transport of polarization ellipse. This paper presents a complete derivation of vector radiative transfer equation for polarized radiation transport in absorption, emission and scattering graded index media. The derivation is based on the analysis of the conserved quantities for polarized light transport along curved trajectory and a novel approach. The obtained transfer equation can be considered as a generalization of the classic vector radiative transfer equation that is only valid for uniform refractive index media. Several variant forms of the transport equation are also presented, which include the form for Stokes parameters defined with a fixed reference and the Eulerian forms in the ray coordinate and in several common orthogonal coordinate systems.Comment: This paper has been submitted to JQSR

Spectral Element Method for Vector Radiative Transfer Equation

A spectral element method (SEM) is developed to solve polarized radiative transfer in multidimensional participating medium. The angular discretization is based on the discrete-ordinates approach, and the spatial discretization is conducted by spectral element approach. Chebyshev polynomial is used to build basis function on each element. Four various test problems are taken as examples to verify the performance of the SEM. The effectiveness of the SEM is demonstrated. The h and the p convergence characteristics of the SEM are studied. The convergence rate of p-refinement follows the exponential decay trend and is superior to that of h-refinement. The accuracy and efficiency of the higher order approximation in the SEM is well demonstrated for the solution of the VRTE. The predicted angular distribution of brightness temperature and Stokes vector by the SEM agree very well with the benchmark solutions in references. Numerical results show that the SEM is accurate, flexible and effective to solve multidimensional polarized radiative transfer problems.Comment: The paper have bee published in JQSR

Case Report - Vertex extradural hematoma in association with Paget's disease of the skull

Paget′s disease of skull usually causes neurological complications such as basilar invagination, cranial neuropathies, etc. Occurrence of extradural hematoma in association with Paget′s disease of skull is rare. A 48 year old man presented with headache and right upper limb weakness, two days after a fall from scooter. CT Scan of brain showed a large extradural hematoma at the vertex with the cranial vault showing features of Paget′s disease. At surgery, no skull fracture or injury to the superior sagittal sinus was evident. There was diffuse oozing from the inner table of the skull, which showed features of Paget′s disease. The extradural hematoma was evacuated and the patient made good recovery.He deteriorated a few hours after surgery. Follow up CT Scan showed diffuse brain swelling with minimal recollection of hematoma. Re-exploration showed a small recollection which was evacuated and the part of the oozing diseased skull was excised. The patient recovered completely. This is the first reported case of vertex extradural hematoma in association with the Paget′s disease of skull. The unusual features are the absence of skull fracture and injury to the superior sagittal sinus. The increased vascularity of the skull due to Paget′s disease has caused the hematoma by diffuse oozing from the inner table

A STUDY OF METALLO BETA-LACTAMASES AMONG IMIPENEM RESISTANT PSEUDOMONAS AERUGINOSA IN A TERTIARY CARE HOSPITAL, TRICHY: STUDY OF METALLO BETA-LACTAMASES AMONG IMIPENEM RESISTANT PSEUDOMONAS AERUGINOSA

Pseudomonas aeruginosa is an important opportunistic pathogen associated with nosocomial infections. The Metallo beta-lactamases are an important class of Carbapenemases which are predominantly produced by Pseudomonas aeruginosa. Objective:The study aimed to study and investigate the prevalaence of Metallo-betalactamases among imipenem resistant Pseudomonas aeruginosa and to evaluate three different methods of screening and detecting Metallo beta-lactamases produced by Pseudomonas aeruginosa. Methods:100 isolates of Pseudomonas aeruginosa were obtained from various clinical specimens, including pus, wound, sputum, urine, body fluids and ET tips received at the laboratory from July 2021 to December 2021. Screening for MBL production among imipenem resistant Pseudomonas aeruginosa was done by double-disc synergy test and combined disc test. Confirmation of MBL production was done by  E-test. Results: Of the 100 Pseudomonas aeruginosa isolates, 16 were Imipenem resistant, of which 16 are MBL producers. Most of the samples are obtained from 50-60 years followed by 40-50 and 60-70 are pus (50%) followed by sputum (20%), urine (15%), body fluids (5%). Of the 100 isolates ,66 strains are isolated from females and 34 Males. Pus samples showed most MBL-producing isolates, accounting for 60.5%. Metallo-beta-lactamases producers accounted for 90% of imipenem resistant cases using combined disc method and 100 % using MBL E strip test. By comparison, DDST retrieved 45% of Pseudomonas MBL producers. Conclusion: The study found moderate prevalence of Pseudomonas MBL producers (16/100). The study supports use of CDDT and DDST for the screening and confirming MBL producers of Pseudomonas aeruginosa by E test where PCR is not available

Optimization method for identifying the source term in an inverse wave equation

In this work, we investigate the inverse problem of identifying a space-wise dependent source term of wave equation from the measurement on the boundary. On the basis of the optimal control framework, the inverse problem is transformed into an optimization problem. The existence and necessary condition of the minimizer for the cost functional are obtained. The projected gradient method and two-parameter model function method are applied to the minimization problem and numerical results are illustrated