Studies on solvent extraction of La(III) using [A336][NO3–] and modeling by statistical analysis and neural network

Solvent extraction of La(III) from acidic nitrate medium has been studied with [A336][NO₃^–] in kerosene. The factors affecting the extraction of La(III) like equilibration time, nitrate ion, extractant and La(III) concentrations, aqueous acidity, O/A ratio variation, nature of diluent, and temperature have been investigated. McCabe-Thiele diagram has been plotted to find out the actual number of theoretical stages needed for complete extraction of lanthanum. The solvent has been successfully regenerated for further use after stripping of the metal. IR studies of [A336][NO₃^–] and La(III) loaded [A336][NO₃^–] have been carried out. Modeling of extraction data has been done using Multiple linear regression analysis and Artificial Neural Network, and the performances have been compared. Error in each case was evaluated in terms of R² and Root mean squared error (RMSE). Maximum extraction of La(III) was 82% when 0.6 M [A336][NO₃^–] was used for extraction. About 98% of the metal has been recovered using 0.2 M HNO₃ as stripping agent. Extractive separation of La(III) and Sm(III) was maximum (β = 65.2) using 0.1 M [A336][NO₃^–]. IR studies revealed formation of lanthanum complex in the extraction process. Artificial Neural Network proved to be better over Multiple linear regression in data prediction.     

A coupled photocatalytic-biological process for degradation of 1-amino-8-naphthol-3, 6-disulfonic acid (H-acid)

 There has been growing emphasis on the development of coupled treatment systems (e.g., advanced oxidation–biological) for treating poorly biodegradable wastewater. An attempt has been made in the present study to couple photocatalytic (TiO₂/UV) pretreatment with conventional activated sludge process to achieve improvement in the biodegradation of H-acid. The combination of titanium dioxide and UV light has been known to generate strong oxidants that degrade several organic pollutants into carbon dioxide via the formation of some intermediates. The intermediates formed may undergo biodegradation readily. Accordingly, photodegradation experiments were carried out initially at an optimized TiO₂ dose and the minimum pretreatment time required for transforming H-acid was identified. For this purpose, UV–vis spectrophotometry and high-performance liquid chromatography (HPLC) were extensively used. Subsequently, it was attempted to biodegrade untreated and pretreated H-acid using activated sludge from the textile industry acclimatized to H-acid. It was found that photocatalytic pretreatment of H-acid for 30 min, during which period approximately 8–10% chemical oxygen demand (COD) removal occurred, can be coupled to second-stage biological treatment for achieving enhanced biodegradation of H-acid.     

Comparison of the phenolic-dependent antioxidant properties of coconut oil extracted under cold and hot conditions

The antioxidant activities of coconut oil extracted under hot and cold conditions were compared. The coconut oil extracted under hot conditions (HECO) contained more phenolic substances than the coconut oil extracted under cold conditions (CECO). The antioxidant potential of HECO was higher than that of CECO as demonstrated by DPPH assay, deoxyribose assay and in vivo assay of serum antioxidant capacity. It is the common belief that virgin coconut oil extracted under cold conditions preserves several thermally unstable antioxidants and, as a result, better beneficial qualities can be expected for virgin coconut oil. However, high temperatures used in the hot extraction of coconut oil favour the incorporation of more thermally stable phenolic antioxidants into coconut oil. Therefore, the consumption of HECO may result in the better improvement of antioxidant related health benefits compared with the consumption of CECO.     

Effect of elevated carbon dioxide and nitrogen management on rice milling qualities

Elevated atmospheric carbon dioxide (CO₂) concentration has a potential impact on the growth and yield of rice (Oryza sativa L.), but little is known on grain milling quality. A field experiment in open-top chamber (OTC) was conducted to assess the effect of elevated CO₂ under varying N management on brown rice, milled rice and head rice yield. The experiment was conducted during wet season (June–November) of the year 2011 and 2012 at Kharagpur, India, using a long-duration, high-yielding cultivar ‘Swarna Sub1,’ which was grown in open field and in OTCs of ambient and elevated CO₂ environment (25 % higher than ambient) with five different N management levels. The elevated CO₂ reduced the brown rice, milled rice and head rice percentage by 1.2, 1.4 and 14 %, respectively, as compared to ambient environment in OTC. Due to elevated CO₂, the reduction in processed yields were 9 and 4 % in brown/milled rice and 21 and 15 % in head rice under sole application of chemical fertilizer and integration of chemical and organic sources, respectively. The decrease in rice milling quality was associated with increasing canopy temperature (+0.8 °C) during grain-filling stage under elevated CO₂ environment. The elevated CO₂ has a substantial adverse impact on grain milling quality, and to some extent, this can be compensated through proper N management.     

GIS-Based Estimation of Soil Loss from Hilly Urban Area Incorporating Hill Cut Factor into RUSLE

Unplanned residential development in hilly areas leads to steep cuts in natural hillslopes, which in turn, results in excessive soil loss. GIS-based Revised Universal Soil Loss Equation (RUSLE), applied in such a case, underestimates soil loss since such near vertical surfaces are not completely projected in orthorectified satellite images. This paper introduces a "hill cut factor (H_f)", which is input into the cover management factor of RUSLE model. Model is validated with observed soil loss data of a mini hilly urban watershed located in Japorigog hill of Guwahati city. GIS-based soil loss estimation has been carried out for two scenarios: with and without consideration of H_f. Results reveal that consideration of H_f in GIS-based RUSLE replicates the picture of erosion more accurately and gives a similar result with observed soil loss data. Without consideration of H_f, RUSLE underestimates annual soil loss from the studied watershed by almost 28% than the observed value. Adequate design of drainage system by using more accurate soil loss information, derived in this way, can lower the urban flood problem caused due to blockage of drains and culverts with sediments brought down from the inhabited hills in a city.     

Tropolone-Conjugated DNA: A Fluorescent Thymidine Analogue Exhibits Solvatochromism,Enzymatic Incorporation into DNA and HeLa Cell Internalization

Tropolone is a non-benzenoid aromatic scaffold with unique photophysical and metal-chelating properties. Recently, it has been conjugated with DNA, and the photophysical properties of this conjugate have been explored. Tropolonyl-deoxyuridine (tr-dU) is a synthetic fluorescent DNA nucleoside analogue that exhibits pH-dependent emissions. However, its solvent-dependent fluorescence properties are unexplored owing to its poor solubility in most organic solvents. It would be interesting to incorporate it into DNA primer enzymatically. This report describes the solvent-dependent fluorescence properties of the silyl-derivative, and enzymatic incorporation of its triphosphate analogue. For practical use, its cell-internalization and cytotoxicity are also explored. tr-dU nucleoside was found to be a potential analogue to design DNA probes and can be explored for various therapeutic applications in the future.