Chemical Composition of the Stem Oil of Aristolochia indica L.

Essential oil from dry matured stem of Aristolochia indica Linn. family Aristolochiaceae was investigated by GC and GC/MS. A total of 15 compounds were identified, representing 91.2% of the total oil. The major constituents of oil were trans-pinocarveol (24.2%), a-pinene (16.4%) and pinocarvone (14.2%)

Sulphate behaviour from dissolution of gypsum in organic acids

The solubility of gypsum in organic acids namely acetic, oxalic, tartaric and succinic acids at low temperature (3

Distribution and nature of organic/mineral bound elements in Assam coals, India

This study focuses on the determination and concentration of twelve elements (Na, K, Ca, Mg, Cr, Mn, Fe, Co, Ni, Cu, Zn and Cd) occurring in sub-bituminous Assam coals and their geochemical association. Distribution of these elements between organic and mineral matters was studied. Comparison of the results of three coals has shown that three elements (Mg, Ca and Mn) are significantly organic bound, while five elements (Fe, Co, Ni, Cu and Zn) are significantly mineral bound; Cd is 50% bound to either organic or mineral matter. FTIR and XRD studies reveal qualitative information about the bonding pattern and nature of components of the mineral matters. The results obtained in this study have considerable geochemical and technological interest

Geotechnical properties of the bank sediments along the Dhansiri River channel,Assam

The bank sediments along the extremely meandered Dhansiri River channel, a south bank tributary of the mighty Brahmaputra River, with erosion potentiality have been investigated to evaluate its certain geotechnical characteristics. The study has shown that the bank sediments are basically composed of CL and ML types of soil. These types of sediments are very much prone to liquefaction which in turn related to erosion susceptibility. The bank stability analysis has differentiated the studied stretch into unstable, at risk and stable zones. Most of the erosion affected zones along the channel reach under study are located within the unstable or at risk zones. The field study around Butalikhowa, Barguriagaon, Golaghat and Duchmuagaon areas along the channel with active erosion activity has supported our contention and practical utility of the present study. It is expected that such type of study will help in providing certain inevitable baseline information for various channel management practices for this extremely flood prone areas of Northeast India

EXTENT OF LEAD IN HIGH-SULFUR ASSAM COALS

This study has been undertaken to understand the precise nature of association of lead in high sulphur Assam coal. Sequential extraction of lead with ammonium acetate, HCl and RuCl 3 solutions havebeen carriedout. RuCl3 hasbeenusedasasuitable reagent fortheextractionoflead.Itisfound thattreatment ofsamplewithCCl 4increasestheextractionofleadbyRuCl 3solution. Theamountof leadinthecoalstudiedvariesbetween43.2and50.4ppm.Ithasbeenfoundthatleadispredominantly occurring in coals in association with organic matter and needs concerted attention to understand its bio-availability. The chemical principles involved therein are also discussed. D 2004 Elsevier B.V. All rights reserved

Cleaning of Indian coals by agglomeration with xylene and hexane

A laboratory scale agglomeration process has been undertaken for cleaning Indian coals using oils namely, xylene and hexane. Maximum organic matter recovery for xylene has been found to be 91.9% whereas with hexane, the value is 54.7% on a dry basis. The highest ash rejection values with xylene (90.7%) and with hexane (89.7%) are almost same. Promising results for rejection of metals (Fe, Mg and Zn) have been observed. It has been found that xylene is more selective than hexane for the agglomeration process. Knowledge gained from this study will be helpful for technological advancement of this kind of work

Production potential of Plumbago zeylanica L. under different harvest schedules and crop geometry

A field experiment on Plumbago zeylanica with three plant densities, namely, 4.9 m-2, 2.7 m-2 and 1.2 m-2 and three harvesting schedules, namely, after first year, second year and third year, was conducted during 1999-2001 at Jorhat (Assam). Plant density significantly influenced number of branches plant-1, shoot and root biomass plant-1 and total yield of roots ha-1. Plant height was found to reduce with the age of the plant. The total dry'root yield was maximum in the plant density 2.7 m-' (5.2 t ha-1). The yield attributing characters, namely, number of branches plant-1 (25.6), shoot biomass plant-1 (408.2 g), root biomass plant-1 (607.4 g) and total root yield (7.1 t ha-1) were maximum when harvested at third year. Maximum phenol, carbohydrate and protein contents were recorded in roots (5.06%, 31.70% and 13.04%, respectively) and leaves (3.40%, 10.60% and 7.84 %, respectively) of plants harvested during the third year. &nbsp