The potential of nitrogen-fixing (NF) bacteria to form a symbiotic relationship with leguminous plants and fix atmospheric nitrogen has been exploited in the field to meet the nitrogen requirement of the latter. This phenomenon provides an alternative to the use of the nitrogenous fertiliser whose excessive and imbalanced use over the decades has contributed to green house emission (N2O) and underground water leaching. Recently, it was observed that non-leguminous plants like rice, sugarcane, wheat and maize form an extended niche for various species of NF bacteria. These bacteria thrive within the plant, successfully colonizing roots, stems and leaves. During the association, the invading bacteria benefit the acquired host with a marked increase in plant growth, vigor and yield. With increasing population, the demand of non-leguminous plant products is growing. In this regard, the richness of NF flora within non-leguminous plants and extent of their interaction with the host definitely shows a ray of hope in developing an ecofriendly alternative to the nitrogenous fertilisers. In this review, we have discussed the association of NF bacteria with various non-leguminous plants emphasizing on their potential to promote host plant growth and yield. In addition, plant growth-promoting traits observed in these NF bacteria and their mode of interaction with the host plant have been described briefly.

Empirical models for the density and the viscosity of squalane (C30H62; 2,6,10,15,19,23-hexamethyltetracosane) have been developed based on an exhaustive review of the data available in the literature and new experimental density and viscosity measurements carried out as a part of this work. The literature review showed there was a substantial lack of density and viscosity data at high temperature (373 to 473) K and high pressure conditions (pressures up to 200 MPa). These gaps were addressed with new experimental measurements carried out at temperatures of (338 to 473) K and at pressures of (1 to 202.1) MPa. The new data were utilized in the model development to improve the density and viscosity calculation of squalane at all conditions including high temperatures and high pressures.The model presented in this work reproduces the best squalane density and viscosity data available based on a new combined outlier and regression algorithm. The combination of the empirical models and the regression approach resulted in models which could reproduce the experimental density data with average absolute percent deviation of 0.04%, bias of 0.000%, standard deviation of 0.05%, and maximum absolute percent deviation of 0.14% and reproduce the experimental viscosity data with average absolute percent deviation of 1.4%, bias of 0.02%, standard deviation of 1.8% and maximum absolute percent deviation of 4.9% over a wide range of temperatures and pressures. Based on the data set used in the model regression (without outliers), the density model is limited to the pressure and temperature ranges of (0.1 to 202.1) MPa and (273 to 525) K, while the viscosity model is limited to the pressure and temperature ranges of (0.1 to 467.0) MPa and (273 to 473) K. These models can be used to calibrate laboratory densitometers and viscometers at relevant hightemperature, high-pressure conditions.

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The genotypic diversity of indigenous bacterial endophytes within stem of tropical maize (Zea mays L.) was determined in field and greenhouse experiments. Strains were isolated from stem tissues of a tropical maize cultivar (PEHM-1) by trituration and surface disinfestation and their population dynamics was determined. Endophytes were found in most of the growing season at populations ranging from 1.

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The demand for fresh spring water recently increased due to intensive domestic, industrial irrigation practices which typically caused depletion of water resources and deterioration of water quality. The spring water quality was analyzed for its major hydrochemistry and hydrochemical evolution of the spring water in the study area. A total of 60 spring water samples were collected from the three kinds of terrain (mountainous, hilly and plain) and analyzed for pH, electrical conductivity (EC), total dissolved solids (TDS), total hardness (TH), calcium (Ca 2þ), magnesium (Mg 2þ), sodium (Na þ), potassium (K þ), bicarbonate (HCO 3 À), sulphate (SO 4 2À), chloride (Cl À), nitrate (NO 3 À), and fluoride (F À). The water quality of drinking purposes was plotted in the Piper trilinear diagram which reveals that spring hydrochemistry is dominated by the alkaline earth and weak acids. Gibbs diagram reveals that the spring water chemistry is primarily controlled by rock-water interaction in the investigated region. The water quality index (WQI), 45% of samples fall in the excellent category, 50% of spring samples fall in good categories for drinking purposes. The pH and TDS are within the permissible limit ranges from 7 to 8.4 and 123to 793 respectively. Based on chemical analysis of the various parameters such as non-carbonate hardness, sodium percentage sodium absorption ratio, residual sodium carbonate were calculated to define the quality of spring water for irrigation purposes. The discharge of spring water was also calculated during the pre-monsoon season and found that 70% of samples have discharge more than 20 L per second (Lps).

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