Rupenaguntla Sambasiva Rao, Professor Retired Andhra University, School of Chemistry | Andhra University (original) (raw)
Papers by Rupenaguntla Sambasiva Rao, Professor Retired Andhra University, School of Chemistry
Analytica Chimica Acta, 1973
The computational quantum chemistry of isonicotinic acid hydrazide (INH), an antitubercular drug,... more The computational quantum chemistry of isonicotinic acid hydrazide (INH), an antitubercular drug, is studied at SEMO level of theory. AMPAC 6.7 package is employed to invoke six hamiltonians, viz., MNDO, MNDO3, MNDO/C, AM1, PM3 and SAM1, to arrive at the optimized geometries in the gaseous phase. Picolinic acid hydrazide (PAH), a valence isomer of INH, and benzoic acid hydrazide (BAH) without a hetero atom in the aromatic ring and their isopropyl derivatives are also investigated. PAH and INH are found to be more stable as compared to BAH, based on electronic and total energies. However, heat of formation is positive (endothermic) and increases in the order: BAH < INH < PAH. The HOMO concentrates on the hydrazide fragment, while LUMO extends over the ring. The orbital-based interactions are more probable with isopropyl derivatives as FMOs spread on either side. Isopropyl derivatives have higher. (ELUMO - EHOMO) and electron affinity values, while ionization potential and hardn...
Annali di chimica, 2002
Computer readable databases have become an integral part of chemical research right from planning... more Computer readable databases have become an integral part of chemical research right from planning data acquisition to interpretation of the information generated. The databases available today are numerical, spectral and bibliographic. Data representation by different schemes--relational, hierarchical and objects--is demonstrated. Quality index (QI) throws light on the quality of data. The objective, prospects and impact of database activity on expert systems are discussed. The number and size of corporate databases available on international networks crossed manageable number leading to databases about their contents. Subsets of corporate or small databases have been developed by groups of chemists. The features and role of knowledge-based or intelligent databases are described.
The Journal of Physical Chemistry
ABSTRACT
Analytica Chimica Acta
Page 1. ANALYTICAL LETTERS, 22(4), 853-860 (1989) DETERMINATION OF ISONICOTINIC ACID HYDRAZIDE US... more Page 1. ANALYTICAL LETTERS, 22(4), 853-860 (1989) DETERMINATION OF ISONICOTINIC ACID HYDRAZIDE USING N-BROMOSUCCINIMIDE KEYWORDS Isonicotinic acid hydrazide, 1-Bromosuccinimide Titrimetric determination. ...
Annali di Chimica
ABSTRACT
Journal of Inorganic and Nuclear Chemistry, 1977
Talanta, 1998
BAQOR is a computer readable database for equilibrium constants in presence of different percenta... more BAQOR is a computer readable database for equilibrium constants in presence of different percentages of water miscible cosolvents. The present version with user friendly software in dBase III+ contains 740 records and runs on any IBM compatible PC. The physico-chemical properties of binary and ternary water-cosolvent mixtures, the equilibrium constants of proton- and metal-ligand complexes are retrievable through pop-up menus. Specific searches by metal-, ligand-, solvent-, and stoichiometry-wise and their combinations is possible. Several display modes-monitor, file and hard copy-are available for the numerical fields as well as for literature citation.
Annali di chimica
Computer readable databases have become an integral part of chemical research right from planning... more Computer readable databases have become an integral part of chemical research right from planning data acquisition to interpretation of the information generated. The databases available today are numerical, spectral and bibliographic. Data representation by different schemes--relational, hierarchical and objects--is demonstrated. Quality index (QI) throws light on the quality of data. The objective, prospects and impact of database activity on expert systems are discussed. The number and size of corporate databases available on international networks crossed manageable number leading to databases about their contents. Subsets of corporate or small databases have been developed by groups of chemists. The features and role of knowledge-based or intelligent databases are described.
Annali di Chimica, 2005
Multivariate data driven calibration models with neural networks (NNs) are developed for binary (... more Multivariate data driven calibration models with neural networks (NNs) are developed for binary (Cu++ and Ca++) and quaternary (K+, Ca++, NO3- and Cl-) ion-selective electrode (ISE) data. The response profiles of ISEs with concentrations are non-linear and sub-Nernstian. This task represents function approximation of multi-variate, multi-response, correlated, non-linear data with unknown noise structure i.e. multi-component calibration/prediction in chemometric parlance. Radial distribution function (RBF) and Fuzzy-ARTMAP-NN models implemented in the software packages, TRAJAN and Professional II, are employed for the calibration. The optimum NN models reported are based on residuals in concentration space. Being a data driven information technology, NN does not require a model, prior- or posterior- distribution of data or noise structure. Missing information, spikes or newer trends in different concentration ranges can be modeled through novelty detection. Two simulated data sets generated from mathematical functions are modeled as a function of number of data points and network parameters like number of neurons and nearest neighbors. The success of RBF and Fuzzy-ARTMAP-NNs to develop adequate calibration models for experimental data and function approximation models for more complex simulated data sets ensures AI2 (artificial intelligence, 2nd generation) as a promising technology in quantitation.
Reactive and Functional Polymers, 1998
The statistical probability of state of a solution containing a reacting receptor M, a ligand A (... more The statistical probability of state of a solution containing a reacting receptor M, a ligand A (and eventually proton H) is described by a molar partition function Z M = exp(-AGIRT) referred to M, or ZA or Zu, respectively. The partition function for one class of sites can be expressed as the function of site constants kj and cooperativity functions yj.i = exp{bj(i -1)). Binding in a single class can be represented by a vector Jpctj whose elements correspond to single species. For more classes of sites, the joined probability is obtained as tensor product of single class vectors giving rise to complexation matrices Mpqr. There is one partition function for each component of the system. If the complexes are of type HPMQAR there are three partition functions Z u, Z, and ZA. The relationships between partition functions and total analytical amounts Tu, TM, T,, respectively are given. The experimental data obtained in a potentiometric titration with electrode reversible to [H] or other free component can be reproduced as the function of site constants kj and cooperativity functions exp{bj(i -l)} for each class j. The best values of kj and bj, can be calculated following a nonlinear least squares procedure by means of a computer program that is here presented. 0 1998 Elsevier Science B.V. All rights reserved.
Talanta, 1998
An algorithm is proposed for the estimation of binding parameters for the interaction of biologic... more An algorithm is proposed for the estimation of binding parameters for the interaction of biologically important macromolecules with smaller ones from electrometric titration data. The mathematical model is based on the representation of equilibria in terms of probability concepts of statistical molecular thermodynamics. The refinement of equilibrium concentrations of the components and estimation of binding parameters (log site constant and cooperativity factor) is performed using singular value decomposition, a chemometric technique which overcomes the general obstacles due to near singularity. The present software is validated with a number of biochemical systems of varying number of sites and cooperativity factors. The effect of random errors of realistic magnitude in experimental data is studied using the simulated primary data for some typical systems. The safe area within which approximate binding parameters ensure convergence has been reported for the non-self starting optimization algorithms.
Polyhedron, 1990
... KMM Krishna Prasad, A. Satyanarayana and C. Kamala Sastry, unpublished work. 19. C. Rambabu, ... more ... KMM Krishna Prasad, A. Satyanarayana and C. Kamala Sastry, unpublished work. 19. C. Rambabu, R. Sambasiva Rao, A. Satyanaryana and PV Krishna Rao. Chim. Acta Turc. 14 (1986), p. 75. 20. R. Sambasiva Rao, A. Satyanarayana and G. Nageswara Rao, unpublished ...
Mikrochimica Acta, 1975
Summary A spot test using 2,3,5-triphenyl tetrazolium chloride for the detection of benzoic acid ... more Summary A spot test using 2,3,5-triphenyl tetrazolium chloride for the detection of benzoic acid hydrazide, and itsm- andp-nitro derivatives, isonicotinic acid hydrazide, salicylic acid hydrazide and phenylacetic acid hydrazide is described. The method consists of treating 0.1 to 0.2 ml of 0.001 % hydrazide (for benzoic acid hydrazide a 0.0001 %) solution with 0.2 to 0.4 ml of 0.02M sodium hydroxide, 0.2 ml of 1% 2,3,5-triphenyl tetrazolium chloride and 0.2 ml of nitrobenzene oriso-butyl methyl ketone in a micro test tube. A reddish-brown colour in the organic phase confirms the presence of an aromatic hydrazide. The identification limits for benzoic acid hydrazide, itsm- andp-nitro derivatives, isonicotinic acid hydrazide, salicylic acid hydrazide, phenylacetic acid hydrazide respectively are: 0.2, 1.0, 1.0, 3.5, 3.0, 2.0µg in 1 ml in nitrobenzene and 0.2, 0.2, 0.1, 3.0, 0.2, 1.5µg in 1 ml iniso- butyl methyl ketone. The interference of various substances and anions has been studied.
Journal of Chemical & Engineering Data, 1992
Fisheries Research, 2008
Piscimetrics deals with software implementation of experimental design, second-generation artific... more Piscimetrics deals with software implementation of experimental design, second-generation artificial intelligence tools, viz. Neural Nets (NNs), genetic algorithms, Fuzzy Logic, Expert Systems, Wavelets and Image analysis in the field of fisheries. A brief sketch of NNs is followed by a review of their applications in forecasting, classification, distribution and fisheries management since 1978. Forecasting in fisheries covers distribution of eggs, recruitment, fish growth/age, biomass and fish catch. Other major areas are identification, abundance and food products, environmental factors and collapse of fishery industry. The data structures are given in tensorial notation. The need for the paradigm shift from classical to multi-level hybrid NNs is emphasized.
Analytica Chimica Acta, 1973
The computational quantum chemistry of isonicotinic acid hydrazide (INH), an antitubercular drug,... more The computational quantum chemistry of isonicotinic acid hydrazide (INH), an antitubercular drug, is studied at SEMO level of theory. AMPAC 6.7 package is employed to invoke six hamiltonians, viz., MNDO, MNDO3, MNDO/C, AM1, PM3 and SAM1, to arrive at the optimized geometries in the gaseous phase. Picolinic acid hydrazide (PAH), a valence isomer of INH, and benzoic acid hydrazide (BAH) without a hetero atom in the aromatic ring and their isopropyl derivatives are also investigated. PAH and INH are found to be more stable as compared to BAH, based on electronic and total energies. However, heat of formation is positive (endothermic) and increases in the order: BAH < INH < PAH. The HOMO concentrates on the hydrazide fragment, while LUMO extends over the ring. The orbital-based interactions are more probable with isopropyl derivatives as FMOs spread on either side. Isopropyl derivatives have higher. (ELUMO - EHOMO) and electron affinity values, while ionization potential and hardn...
Annali di chimica, 2002
Computer readable databases have become an integral part of chemical research right from planning... more Computer readable databases have become an integral part of chemical research right from planning data acquisition to interpretation of the information generated. The databases available today are numerical, spectral and bibliographic. Data representation by different schemes--relational, hierarchical and objects--is demonstrated. Quality index (QI) throws light on the quality of data. The objective, prospects and impact of database activity on expert systems are discussed. The number and size of corporate databases available on international networks crossed manageable number leading to databases about their contents. Subsets of corporate or small databases have been developed by groups of chemists. The features and role of knowledge-based or intelligent databases are described.
The Journal of Physical Chemistry
ABSTRACT
Analytica Chimica Acta
Page 1. ANALYTICAL LETTERS, 22(4), 853-860 (1989) DETERMINATION OF ISONICOTINIC ACID HYDRAZIDE US... more Page 1. ANALYTICAL LETTERS, 22(4), 853-860 (1989) DETERMINATION OF ISONICOTINIC ACID HYDRAZIDE USING N-BROMOSUCCINIMIDE KEYWORDS Isonicotinic acid hydrazide, 1-Bromosuccinimide Titrimetric determination. ...
Annali di Chimica
ABSTRACT
Journal of Inorganic and Nuclear Chemistry, 1977
Talanta, 1998
BAQOR is a computer readable database for equilibrium constants in presence of different percenta... more BAQOR is a computer readable database for equilibrium constants in presence of different percentages of water miscible cosolvents. The present version with user friendly software in dBase III+ contains 740 records and runs on any IBM compatible PC. The physico-chemical properties of binary and ternary water-cosolvent mixtures, the equilibrium constants of proton- and metal-ligand complexes are retrievable through pop-up menus. Specific searches by metal-, ligand-, solvent-, and stoichiometry-wise and their combinations is possible. Several display modes-monitor, file and hard copy-are available for the numerical fields as well as for literature citation.
Annali di chimica
Computer readable databases have become an integral part of chemical research right from planning... more Computer readable databases have become an integral part of chemical research right from planning data acquisition to interpretation of the information generated. The databases available today are numerical, spectral and bibliographic. Data representation by different schemes--relational, hierarchical and objects--is demonstrated. Quality index (QI) throws light on the quality of data. The objective, prospects and impact of database activity on expert systems are discussed. The number and size of corporate databases available on international networks crossed manageable number leading to databases about their contents. Subsets of corporate or small databases have been developed by groups of chemists. The features and role of knowledge-based or intelligent databases are described.
Annali di Chimica, 2005
Multivariate data driven calibration models with neural networks (NNs) are developed for binary (... more Multivariate data driven calibration models with neural networks (NNs) are developed for binary (Cu++ and Ca++) and quaternary (K+, Ca++, NO3- and Cl-) ion-selective electrode (ISE) data. The response profiles of ISEs with concentrations are non-linear and sub-Nernstian. This task represents function approximation of multi-variate, multi-response, correlated, non-linear data with unknown noise structure i.e. multi-component calibration/prediction in chemometric parlance. Radial distribution function (RBF) and Fuzzy-ARTMAP-NN models implemented in the software packages, TRAJAN and Professional II, are employed for the calibration. The optimum NN models reported are based on residuals in concentration space. Being a data driven information technology, NN does not require a model, prior- or posterior- distribution of data or noise structure. Missing information, spikes or newer trends in different concentration ranges can be modeled through novelty detection. Two simulated data sets generated from mathematical functions are modeled as a function of number of data points and network parameters like number of neurons and nearest neighbors. The success of RBF and Fuzzy-ARTMAP-NNs to develop adequate calibration models for experimental data and function approximation models for more complex simulated data sets ensures AI2 (artificial intelligence, 2nd generation) as a promising technology in quantitation.
Reactive and Functional Polymers, 1998
The statistical probability of state of a solution containing a reacting receptor M, a ligand A (... more The statistical probability of state of a solution containing a reacting receptor M, a ligand A (and eventually proton H) is described by a molar partition function Z M = exp(-AGIRT) referred to M, or ZA or Zu, respectively. The partition function for one class of sites can be expressed as the function of site constants kj and cooperativity functions yj.i = exp{bj(i -1)). Binding in a single class can be represented by a vector Jpctj whose elements correspond to single species. For more classes of sites, the joined probability is obtained as tensor product of single class vectors giving rise to complexation matrices Mpqr. There is one partition function for each component of the system. If the complexes are of type HPMQAR there are three partition functions Z u, Z, and ZA. The relationships between partition functions and total analytical amounts Tu, TM, T,, respectively are given. The experimental data obtained in a potentiometric titration with electrode reversible to [H] or other free component can be reproduced as the function of site constants kj and cooperativity functions exp{bj(i -l)} for each class j. The best values of kj and bj, can be calculated following a nonlinear least squares procedure by means of a computer program that is here presented. 0 1998 Elsevier Science B.V. All rights reserved.
Talanta, 1998
An algorithm is proposed for the estimation of binding parameters for the interaction of biologic... more An algorithm is proposed for the estimation of binding parameters for the interaction of biologically important macromolecules with smaller ones from electrometric titration data. The mathematical model is based on the representation of equilibria in terms of probability concepts of statistical molecular thermodynamics. The refinement of equilibrium concentrations of the components and estimation of binding parameters (log site constant and cooperativity factor) is performed using singular value decomposition, a chemometric technique which overcomes the general obstacles due to near singularity. The present software is validated with a number of biochemical systems of varying number of sites and cooperativity factors. The effect of random errors of realistic magnitude in experimental data is studied using the simulated primary data for some typical systems. The safe area within which approximate binding parameters ensure convergence has been reported for the non-self starting optimization algorithms.
Polyhedron, 1990
... KMM Krishna Prasad, A. Satyanarayana and C. Kamala Sastry, unpublished work. 19. C. Rambabu, ... more ... KMM Krishna Prasad, A. Satyanarayana and C. Kamala Sastry, unpublished work. 19. C. Rambabu, R. Sambasiva Rao, A. Satyanaryana and PV Krishna Rao. Chim. Acta Turc. 14 (1986), p. 75. 20. R. Sambasiva Rao, A. Satyanarayana and G. Nageswara Rao, unpublished ...
Mikrochimica Acta, 1975
Summary A spot test using 2,3,5-triphenyl tetrazolium chloride for the detection of benzoic acid ... more Summary A spot test using 2,3,5-triphenyl tetrazolium chloride for the detection of benzoic acid hydrazide, and itsm- andp-nitro derivatives, isonicotinic acid hydrazide, salicylic acid hydrazide and phenylacetic acid hydrazide is described. The method consists of treating 0.1 to 0.2 ml of 0.001 % hydrazide (for benzoic acid hydrazide a 0.0001 %) solution with 0.2 to 0.4 ml of 0.02M sodium hydroxide, 0.2 ml of 1% 2,3,5-triphenyl tetrazolium chloride and 0.2 ml of nitrobenzene oriso-butyl methyl ketone in a micro test tube. A reddish-brown colour in the organic phase confirms the presence of an aromatic hydrazide. The identification limits for benzoic acid hydrazide, itsm- andp-nitro derivatives, isonicotinic acid hydrazide, salicylic acid hydrazide, phenylacetic acid hydrazide respectively are: 0.2, 1.0, 1.0, 3.5, 3.0, 2.0µg in 1 ml in nitrobenzene and 0.2, 0.2, 0.1, 3.0, 0.2, 1.5µg in 1 ml iniso- butyl methyl ketone. The interference of various substances and anions has been studied.
Journal of Chemical & Engineering Data, 1992
Fisheries Research, 2008
Piscimetrics deals with software implementation of experimental design, second-generation artific... more Piscimetrics deals with software implementation of experimental design, second-generation artificial intelligence tools, viz. Neural Nets (NNs), genetic algorithms, Fuzzy Logic, Expert Systems, Wavelets and Image analysis in the field of fisheries. A brief sketch of NNs is followed by a review of their applications in forecasting, classification, distribution and fisheries management since 1978. Forecasting in fisheries covers distribution of eggs, recruitment, fish growth/age, biomass and fish catch. Other major areas are identification, abundance and food products, environmental factors and collapse of fishery industry. The data structures are given in tensorial notation. The need for the paradigm shift from classical to multi-level hybrid NNs is emphasized.