Toxicity of individual and mixture of organic compounds to P. Phosphoreum and S. Capricornutum using interpretable simple structural parameters.

Human and environmental ecosystem beings are exposed to multicomponent compound mixtures but the toxicity nature of compound mixtures is not alike to the individual chemicals. This work introduces four models for the prediction of the negative logarithm of median effective concentration (pEC) of individual chemicals to marine bacteria Photobacterium Phosphoreum (P. Phosphoreum) and algal test species Selenastrum Capricornutum (S.

The use of simple structural parameters of organic compounds to assess their PUF-air partition coefficients.

A novel approach is introduced for the reliable prediction of PUF-air partition coefficients of organic compounds, which can determine the environmental fate of organic compounds during interactions with air, soil, and water. The biggest accessible measured data of PUF-air partition coefficients for 170 chemicals are used to develop and test the novel model. In comparison to available quantitative structure-property relationship (QSPR) methods for the prediction of PUF-air partition coefficients that need complex descriptors, the here used descriptors are simpler.

A novel approach for assessment of antitrypanosomal activity of sesquiterpene lactones through additive and non-additive molecular structure parameters.

Human African trypanosomiasis (HAT) or sleeping sickness is a protozoan neglected tropical disease, which is the main health worry in more than 20 countries in Africa. A novel approach is presented to predict the antitrypanosomal activity of sesquiterpene lactones (STLs) in terms of biological activity (pIC). The largest reported data set of pIC for Trypanosoma brucei rhodesiense (Tbr) as one form of HAT are used to derive and test the new model.

Simple method for assessment of activities of thrombin inhibitors through their molecular structure parameters.

Thrombi (blood clots) form in blood vessels in thromboembolic disorders, which are among the main reasons for death in the world. A novel approach is presented to predict thrombin inhibitory activities ((log(10/K) (nM)) of some classes of non-peptidic thrombin inhibitors. The largest reported data set of log(10/K) for 260 thrombin inhibitors are used to derive and test the new model where it can be easily applied through a computer code.

A novel model for prediction of stability constants of the thiosemicarbazone ligands with different types of toxic heavy metal ions using structural parameters and multivariate linear regression method.

A novel model is presented for reliable estimation of the stability constants of the thiosemicarbazone ligands with different types of toxic heavy metal ions (log β) in an aqueous solution, which has wide usage in environmental safety and ecotoxicology applications. The biggest reported data of log β for 120 metalthiosemicarbazone complexes are used for deriving and testing the novel model. In contrast to available methods where they need the two-dimensional (2D) and three-dimensional (3D) complex molecular descriptors as well as expert users and computer codes, the novel correlation uses four additive and two non-additive structural parameters of thiosemicarbazone ligands.

A simple method for assessing chemical toxicity of ionic liquids on Vibrio fischeri through the structure of cations with specific anions.

Both water and non-water soluble ionic liquids (ILs) may be toxic where ILs soluble in water can be released into aquatic ecosystems. Toxicity of ILs can be determined as effective nominal concentration EC because it is important to assess the toxicity of ILs by an inhibition assay, which can evaluate the toxicological danger of ILs. A novel model is introduced for desk calculations of chemical toxicity of ILs based on Vibrio fischeri with more reliance on their answers as one could attach to the more complex outputs.

Application of laser-induced breakdown spectroscopy to assess palladium catalyst deactivation.

This work introduces a new method for the investigation of palladium (Pd) catalyst deactivation by laser-induced breakdown spectroscopy (LIBS). For this purpose, deactivation of Pd/(OH)/C catalyst for synthesis of hexanitrohexaazaisowurtzitane (HNIW or CL-20) as a high-performance energetic compound was studied. The LIBS spectrum of fresh catalyst (Pd/(OH)/C) with 10% Pd was compared to spent catalyst (Pd/C) containing 7% Pd.

Energetic materials identification by laser-induced breakdown spectroscopy combined with artificial neural network.

In this study, for the first time to the best of our knowledge, a combination of the laser-induced breakdown spectroscopy (LIBS) technique and artificial neural network (ANN) analysis has been implemented for the identification of energetic materials, including TNT, RDX, black powder, and propellant. Also, aluminum, copper, inconel, and graphite have been used for more accurate investigation and comparison. After the LIBS test and spectrum acquisition on all samples in both air and argon ambient, optimized neural networks were designed by LIBS data.

Relationship between the results of laser-induced breakdown spectroscopy and dynamical mechanical analysis in composite solid propellants during their aging.

Laser-induced breakdown spectroscopy (LIBS) has been used to analyze thermal aging in AP/HTPB composite solid propellants, where AP and HTPB are ammonium perchlorate and hydroxyl-terminated polybutadiene, respectively. The method of accelerated aging was used to obtain samples of different ages. Dynamical mechanical analysis results have been provided in order to validate the LIBS results.

Approach for determination of detonation performance and aluminum percentage of aluminized-based explosives by laser-induced breakdown spectroscopy.

Energetic materials containing aluminum powder are hazardous compounds, which have wide applications as propellants, explosives, and pyrotechnics. This work introduces a new method on the basis of the laser-induced breakdown spectroscopy technique in air and argon atmospheres to investigate determination of aluminum content and detonation performance of 1,3,5-trinitro-1,3,5-triazine (RDX)-based aluminized explosives. Plasma emission of aluminized RDX explosives are recorded where atomic lines of Al, C, H, N, and O, as well as molecular bands of AlO and CN are identified.

Stereochemistry and spectroscopic analysis of bis-Betti base derivatives of 2,3-dihydroxynaphthalene.

Density functional theory (DFT) was used to study the stereochemistry, thermodynamic stability, and spectra of recently synthesized bis-Betti base derivatives of 2,3-dihydroxynaphthalene obtained through multicomponent reactions of 2,3-dihydroxynaphthalene with aminoisoxazole and benzaldehyde derivatives. The stereochemistry of the products was investigated by theoretically calculating the infrared (IR) and proton nuclear magnetic resonance ((1)H NMR) spectra of the diastereomers and comparing them to the corresponding experimental data. The thermochemical properties of the reactions, including the enthalpy, internal energy, entropy, and Gibbs free energy, were also calculated.

Accurate prediction of the toxicity of benzoic acid compounds in mice via oral without using any computer codes.

Most of benzoic acid derivatives are toxic, which may cause serious public health and environmental problems. Two novel simple and reliable models are introduced for desk calculations of the toxicity of benzoic acid compounds in mice via oral LD(50) with more reliance on their answers as one could attach to the more complex outputs. They require only elemental composition and molecular fragments without using any computer codes.

Simple method for reliable predicting flash points of unsaturated hydrocarbons.

This work introduces a simple method for prediction of the flash point of different classes of unsaturated hydrocarbons including alkenes, alkynes and aromatics. Elemental composition is used as a core function that can be revised for some compounds by a correcting function. The predicted flash points for a data set of 173 unsaturated hydrocarbons are in good agreement with the measured values such that the root mean square (rms) error is 9 K.

Prediction of the condensed phase heat of formation of energetic compounds.

A new reliable simple model is presented for estimating the condensed phase heat of formation of important classes of energetic compounds including polynitro arene, polynitro heteroarene, acyclic and cyclic nitramine, nitrate ester and nitroaliphatic compounds. For CHNO energetic compounds, elemental compositions as well as increasing and decreasing energy content parameters are used in the new method. The novel correlation is tested for 192 organic compounds containing complex molecular structures with at least one nitro, nitramine or nitrate energetic functional groups.

A new approach to predict the strength of high energy materials.

This paper presents a new approach to predict the strength of energetic compounds in which there are important classes of high explosives including nitroaromatics, acyclic and cyclic nitramines, nitrate esters and nitroaliphatics. For C(a)H(b)N(c)O(d) compounds, the ratio of carbon to oxygen atoms and the predicted heat of detonation on the basis of the H(2)O-CO(2) arbitrary have been used to calculate the strength of an explosive. The new model can give good predictions for mentioned energetic compounds as determined by the Trauzl test.

A new method for predicting the heats of combustion of polynitro arene, polynitro heteroarene, acyclic and cyclic nitramine, nitrate ester and nitroaliphatic compounds.

A new method is presented for estimating the gross and net heats of combustion of important classes of energetic compounds including polynitro arene, polynitro heteroarene, acyclic and cyclic nitramine, nitrate ester and nitroaliphatic compounds. Elemental compositions as well as the presence of some specific polar groups and molecular fragments are important parameters in the new model. The novel method can be easily used for any complex organic compounds with at least one nitro, nitramine or nitrate functional groups by which the predictions of their heats of combustion by the available methods are inaccurate or difficult.

Using molecular structure for reliable predicting enthalpy of melting of nitroaromatic energetic compounds.

In this work, a reliable simple method has been introduced for predicting enthalpy of melting of nitroaromatic energetic compounds through their molecular structures. This method can be used for a wide range of nitroaromatics including halogenated nitroaromatic compounds. The contribution of hydrogen bonding and polar groups as well as structural parameters can be used to improve the predicted values on the basis of the number of carbon, nitrogen and oxygen atoms.

Improved prediction of heats of sublimation of energetic compounds using their molecular structure.

A simple method is used to predict heats of sublimation of energetic compounds, which include nitroaromatics, nitramines, nitroaliphatics and nitrate esters. Molecular weight, some specific functional groups and structural parameters are fundamental factors in the new model. The root-mean-square deviation (rms) from experiment has been calculated for the predicted results of 92 different compounds.

A new computer code to evaluate detonation performance of high explosives and their thermochemical properties, part I.

In this paper a new simple user-friendly computer code, in Visual Basic, has been introduced to evaluate detonation performance of high explosives and their thermochemical properties. The code is based on recently developed methods to obtain thermochemical and performance parameters of energetic materials, which can complement the computer outputs of the other thermodynamic chemical equilibrium codes. It can predict various important properties of high explosive including velocity of detonation, detonation pressure, heat of detonation, detonation temperature, Gurney velocity, adiabatic exponent and specific impulse of high explosives.

New method for predicting melting points of polynitro arene and polynitro heteroarene compounds.

This work introduces a new method for prediction of melting points of nitroaromatic compounds, including polynitro arenes and polynitro heteroarenes, through their molecular structures. The new model extends earlier work, which was used for carbocyclic nitroaromatic compounds, to estimate melting points of heterocyclic aromatic compounds. Some specific functional groups and structural parameters can be used to improve the predicted values on the basis of the number of carbon, hydrogen and nitrogen atoms.

A new approach to predict the condensed phase heat of formation in acyclic and cyclic nitramines, nitrate esters and nitroaliphatic energetic compounds.

This paper presents a new approach to predict the condensed phase heat of formation in important classes of energetic compounds including acyclic and cyclic nitramines, nitrate esters and nitroaliphatics. The condensed phase heat of formation has been expressed by a combination of a core heat of formation, which is a function of elemental composition of the energetic compound, and correction functions. The correction functions for some energetic compounds can have decreasing or increasing effects on the basis of thermodynamic stability.

Predicting condensed phase heat of formation of nitroaromatic compounds.

A new approach has been introduced to predict condensed phase heats of formation of nitroaromatic compounds with the general formula C(a)H(b)N(c)O(d). Elemental composition, some specific functional groups or structural parameters as well as the number of aromatic rings under certain conditions can be used here. The present method has been used for 82 nitroaromatics and predicted results were compared to the latest available experimental data.

A reliable simple method to estimate density of nitroaliphatics, nitrate esters and nitramines.

In this work, a new simple method is presented to estimate crystal density of three important classes of explosives including nitroalphatics, nitrate esters and nitramines. This method allows reliable prediction of detonation performance for the above compounds. It uses a new general correlation containing important explosive parameters such as the number of carbon, hydrogen, nitrogen and two other structural parameters.

Reliable prediction of electric spark sensitivity of nitramines: a general correlation with detonation pressure.

For nitramines, a general correlation has been introduced to predict electric spark sensitivity through detonation pressure. New method uses maximum obtainable detonation pressure as a fundamental relation so that it can be corrected for some nitramines which have some specific molecular structure. There is no need to use crystal density and heat of formation of nitramine explosives for predicting detonation pressure and electric spark sensitivity.

Prediction of detonation performance of CHNO and CHNOAl explosives through molecular structure.

A new pathway has been introduced to predict detonation pressure of CHNO and CHNOAl explosives. Although aluminized explosives can have Chapman-Jouguet detonation performance significantly different from those expected from existing thermodynamic computer codes for equilibrium and steady state calculations, new correlation can also be used here. Molecular structures of CHNO and CHNOAl explosives are the only necessary parameters that would be needed in this new scheme.