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Multiyear measurements of spectral properties of aerosol absorption are examined over four geographically distinct locations of northeastern India. Results indicated significant spatiotemporal variation in aerosol absorption coefficients (σabs) with highest values in winter and lowest in monsoon. The western parts of the region, close to the outflow of Indo‐Gangetic Plains, showed higher values of σabs and black carbon (BC) concentration—mostly associated with fossil fuel combustion. But, the eastern parts showed higher contributions from biomass‐burning aerosols, as much as 20–25% to the total aerosol absorption, conspicuously during premonsoon season. This is attributed to a large number of burning activities over the Southeast Asian region, as depicted from Moderate Resolution Imaging Spectroradiometer fire count maps, whose spatial extent and magnitude peaks during March/April. The nearly consistent high values of aerosol index (AI) and layer height from Ozone Monitoring Instrument indicate the presence of absorbing aerosols in the upper atmosphere. The observed seasonality has been captured fairly well by Goddard Chemistry Aerosol Radiation and Transport (GOCART) as well as Weather Research and Forecasting–Chemistry (WRF‐Chem) model simulations. The ratio of column‐integrated optical depths due to particulate organic matter and BC from GOCART showed good coincidence with satellite‐based observations, indicating the increased vertical dispersion of absorbing aerosols, probably by the additional local convection due to higher fire radiative power caused by the intense biomass‐burning activities. In the WRF‐Chem though underperformed by different magnitude in winter, the values are closer or overestimated near the burnt areas. Atmospheric forcing due to BC was highest (~30 Wm−2) over the western part associated with the fossil fuel combustion.

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A GC-MS based analytical approach was undertaken to understand the metabolomic responses of seedlings of 2 salt sensitive (Sujala and MTU 7029) and 2 tolerant varieties (Bhutnath, and Nonabokra) of indica rice (Oryza sativa L.) to NaCl induced stress. The 4 varieties responded differently to NaCl treatment with respect to the conserved primary metabolites (sugars, polyols, amino acids, organic acids and certain purine derivatives) of the leaf of rice seedlings. However, there were significant differences in salt induced production of chorismic acid derivatives. Serotonin level was increased in both the salt tolerant varieties in response to NaCl induced stress. In both the salt tolerant varieties, increased production of the signaling molecule gentisic acid in response to NaCl treatment was noticed. Salt tolerant varieties also produced increased level of ferulic acid and vanillic acid. In the salt sensitive varieties, cinnamic acid derivatives, 4-hydroxycinnamic acid (in Sujala) and 4-hydroxybenzoic acid (in MTU 7029), were elevated in the leaves. So increased production of the 2 signaling molecules serotonin and gentisic acid may be considered as 2 important biomarker compounds produced in tolerant varieties contributing toward NaCl tolerance.

[1] Changes in equatorial D-region electron density are studied using subionospherically propagating VLF signal at 18.2 kHz over a distance of 2200 km during the total solar eclipse of 22 July 2009. There are very few studies about the eclipse's effects on the equatorial lower ionosphere in the scientific literature. In the light of that, the objective of the present work is to study the effects of the eclipse on the dynamics of the equatorial lower ionosphere during ionospheric sunrise transition period. In the present case, great circle path between VLF transmitter and receiver falls totally in partial eclipse zone, having a maximum solar obscuration of 90% and an average obscuration of 74%. Results show an average decrease of 3.2 dB in signal strength compared to control days during peak solar obscuration over the path. A comparison with previous studies shows an increase both in lower ionosphere virtual reflection height (H′) and Wait inverse scale height parameter , respectively. During maximum eclipse over the path, the model profile shows an average 80% drop in electron density at a height of 71 km at equatorial lower ionosphere. A nonlinear variation of lower ionosphere electron density with solar radiation is found as opposed to the model study proposed by previous workers.Citation: Guha, A., B. K. De, R. Roy, and A. Choudhury (2010), Response of the equatorial lower ionosphere to the total solar eclipse of 22 July 2009 during sunrise transition period studied using VLF signal,

Physical refining of rice bran oil (RBO) with acidity between 4.0 and 12.4% has been investigated in relation to degumming and dewaxing pretreatments. It appears that physical refining after combined low-temperature (10°C) degumming-dewaxing produces good-quality RBO with respect to color, free fatty acid, oryzanol, and tocopherol content. JAOCS 75, 1683JAOCS 75, -1686JAOCS 75, (1998. KEY WORDS:Degumming, dewaxing, physical refining, rice bran oil.Rice bran oil (RBO) of edible grade contains 2.0-20.0% free fatty acids (FFA), depending on the quality of bran. It is difficult to refine RBO because of its high FFA, unsaponifiable matter (UM), and color.Among the various approaches for refining high-as well as low-FFA RBO, the most widely used steps are degumming, dewaxing, neutralization of FFA, bleaching, and deodorization. However, the major problems of chemical refining are production of large quantities of soap stock, high refining losses, and environmental pollution (1).Bhattacharyya et al.(2) proposed a process for obtaining edible-quality oil from high-FFA RBO by a combination of miscella dewaxing and miscella refining. Deacidification of high-FFA RBO (15-30%) by re-esterification with glycerol and alkali neutralization also has been proposed (3,4). This combined process, followed by bleaching and deodorization, yields good-quality oil.Biorefining, i.e., removal of FFA by esterification with added glycerol and specific lipases, is a newer approach. Bhattacharyya et al. (5) have successfully developed a process to bring down the FFA from 30 to 3.6% for RBO, and subsequent alkali refining, bleaching, and deodorization produced excellent-quality RBO. The main barrier of this process is the cost of the enzyme.There has been growing interest in physical refining of RBO. The process is attractive because of its simplicity, lack of environmental impact, low oil losses, and good-quality product (6). Physical refining removes the FFA, thereby eliminating soap stock and reducing neutral oil losses to minimal levels. Prabhakar et al. (7) have reported that the higher refining loss of RBO and darkening of color is due to the existence of wax, oryzanol, and phosphatides. Practical experience has shown that acceptable results may be obtained during physical refining if good-quality raw material is used. Incomplete removal of undesirable components during pretreatments also affects the quality of the final product.The removal of lipid and nonlipid components during degumming, dewaxing, and bleaching is therefore of prime importance. This investigation has focused on the removal of gummy materials and waxes under various conditions prior to physical refining, so that the quality of RBO as a final product is not impaired. MATERIALS AND METHODSCrude RBO of varying acidity were supplied by local oil mills.FFA, peroxide value (PV) and UM in crude and refined oils were determined according to standard AOCS methods (8). Color of the crude and refined oils was determined with a Lovibond Tintometer (8).Total gum and wax content w...