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Background Green plants are found to be an effective reservoir for bioactive molecules and can provide appreciable sources of antimicrobial agents. Antibacterial activity of solvent extracts of Euphorbia cotinifolia leaves was tested by agar cup diffusion and broth microdilution methods against some common human pathogenic bacteria viz., Bacillus cereus, Klebsiella pneumonia, Enterobacter aerogenes, Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Salmonella typhi. The methanol extract of Euphorbia cotinifolia was subjected to a silica gel column, leading to the isolation of a bioactive compound 1. The structure of compounds was elucidated by spectroscopic techniques and assessed for their antibacterial activity against several human pathogenic bacteria. Results The inhibition zone ranged against some common human pathogenic bacteria was 15.25–19.50 mm, 13.50–19.25 mm, 12–18.50 mm, 15–20 mm, and 13–19 mm for ECMF1, ECMF2, ECMF3, compounds 1, respectively. The MIC was found to be in the range 91–729 μg/ml for the fractions. The inhibition range was recorded between 12–19 and 10–14 mm for methanol and ethyl acetate extracts, respectively. K. pneumoniae, E. aerogenes, and B. subtilis were highly susceptible to methanol extract with the maximum inhibition zone of 19 mm. The MIC of the compound 1 against human pathogens was 78–833 μg/ml. Conclusion The present study results suggest that tested plant extracts have moderate to potent antibacterial activity due to the occurrence of phenols and flavonoids in the extracts. The defensive property of natural antibacterials is mainly due to the presence of these major groups, vitamins, phenols, flavonoids, and carotenoids. In the present study, biologically active diterpene was isolated and the structures of the new diterpenoids isolated from E. cotinifolia were closely related to an ingenol ester.

In the classical p-median problem, the objective is to find a set Y of p vertices on an undirected graph $$G=(V,E)$$ in such a way that $$ Y \subseteq V$$ and the sum of distances from all the vertices to their respective closest vertices in Y is minimized. In this paper, we have considered the weighted case where every vertex in G has either a positive or a negative weight under two different objective functions, viz. the sum of the minimum weighted distances and the sum of the weighted minimum distances. In this paper, we have proposed a hybrid artificial bee colony (ABC) algorithm for the positive/negative weighted p-median problem where each solution generated by ABC algorithm is improved by an interchange based randomized local search. In addition, an interchange based exhaustive local search is applied on some of the best solutions obtained after the execution of ABC algorithm in a bid to further improve their quality. We have compared our approach with the state-of-the-art approaches available in the literature on the standard benchmark instances. Computational results demonstrate the effectiveness of our approach.

This paper proposes a hybrid artificial bee colony algorithm for the cooperative maximum covering location problem (CMCLP) on a network. In location covering problems, it is assumed that each facility generates a signal whose strength decreases with the increase in distance and a demand point is considered to be covered if the total signal strength received by it from various facilities exceeds a certain threshold. The objective of the CMCLP is to locate the facilities in such a way that maximizes the total demands covered. The proposed hybrid approach obtained better quality solutions in comparison to the methods available in the literature.

The incumbent trend in process industry is to deploy information and communication technology (ICT), enabled wired process control systems. Distributed control system, supervisory control and data acquisition systems with wireless open loop control systems are commonly used to facilitate the same. However, wireless closed loop control system is a flexible system, which is not yet been introduced in the process industry. The major theme of this research work is to model the enablers of implementing ICT enabled control system in the process industry based on their interrelationships, with the help of industrialists in an oil refinery in central Kerala. The relationships of enablers have been established effectively by interpretive structural modeling (ISM). However, the interpretation of links is comparatively weak in ISM. Qualitative criteria are often accompanied by obscurities and vagueness. To compensate for this, ISM is further modified by total ISM (TISM). TISM is a novel qualitative modeling technique that has been used by researchers in diverse fields of investigation. For this study, TISM is used to develop the performance model for the enablers of a flexible control system for industry. The structural model developed using this methodology helps to understand the interaction between the various elements of enablers. After the model is developed, it is further subjected to assessment by a different group of domain experts so as to enhance its validity.

Groundwater availability depends on its accessibility, as well as on its quality. Factor analysis (FA) has been used to analyze quality problems and provide strategies for water resources exploitation. The present study demonstrated the use of factor analysis to evaluate temporal variations in groundwater quality and find latent sources of water pollution in coastal areas of Ramanathapuram District, Tamil Nadu, India. The data set included data of eleven water quality parameters viz., pH, electrical conductivity, salinity, total dissolved solids, total alkalinity, calcium hardness, magnesium hardness, total hardness, chloride and fluoride for two different seasons (pre- and post-monsoon) in 2012. FA of the two seasons resulted in two latent factors accounting for 80.38 % of total variance for pre-monsoon (summer) and 73.03 % for post-monsoon (winter) in the water quality data sets. The results obtained from FA prove that the groundwater quality in winter is better than that of summer. Langelier Saturation Index was used to find out scaling and corrosive tendency of the groundwater samples for the study area. Karl Pearson correlation matrix was used to study the correlation between the studied water quality parameters. Hence, the analysis suggests that FA techniques are useful tools for identification of influence of various quality parameters on overall nature of the groundwater.