Effect of Surface Treatment and Fiber Orientation on the Tensile and Morphological Properties of Banana Stem Fiber Reinforced Natural Rubber Composite

A mixture of NaOH and Na2SO3 was used in modification of banana stem fibers (BSF). Unidirectional BSF reinforced natural rubber (NR) lamina composites were made using compression moulding method. The results of the tensile loading in 0°, 45° and 90° to the fiber directions of the composite with fiber mass fraction of 30% were studied. Surface modification of the BSF with a mixture of 4% NaOH and 2% Na2SO3 increased the tensile strength and elastic modulus of the composite to 4.03 MPa and 147.34 MPa respectively from 3.12 MPa and 84.30 MPa of the untreated. Variation in properties due to fiber orintations was observed indicating a higher value of properties in the 0° fiber orientation than in 45° and 90° directions. The result of scanning electron microscope (SEM) micrographs of the surfaces of the fibers indicted an improvement in bonding of the fiber bundles prior to lamination with natural rubber as a result of surface treatment which resulted in its higher tensile strength.

Lipid enhancement in microalgae by temporal phase separation:Use of indigenous sources of nutrients

Microalgae have been recommended as superior candidate for fuel production because of their advantages of higher photosynthetic efficiency, biomass & lipid productivity, and faster growth rate as compared to other energy crops. To meet up all these criteria, we have developed a continuous outdoor micro-algal raceway pond reactor(RPR) and a lab scale indoor tubular photo bioreactor(PBR) for biofuel production. An attempt to utilise indigenous sources of nutrients to improve the economics also revealed that micro-algal culturing can also be used as a mode of nutrient removal and water treatment. The photosynthetic rate and lipid production were enhanced by arresting daytime cell division and promoting night-time cell division. A 50% lipid improvement was observed for the particular algal consortia. Microscopic studies revealed that temporal phase separation could be achieved by adjusting nutrient distribution pattern. To monitor temporal phase separation, it is required to know DNA multiplication model. Quantification of g DNA in RPR confirmed that cell division happens during the night which positively affects the photosynthetic efficiency and lipid productivity of microalgae.

Significance of Impurity Mineral Identification in the Value Addition of Kaolin – A Case Study with Reference to an Acidic Kaolin from India

Kaolin or china clay is a versatile industrial mineral with wide technological applications and is abundantly available in India. The major mineral in kaolin is kaolinite (Al2O3.2SiO2.2H2O). The common ancillary / impurity minerals occurring with kaolin include parent rocks like feldspar and mica, quartz, ferruginous, titanoferrous and carbonaceous materials. The most deleterious impurities in kaolin are iron minerals which imparts colour to the white kaolin. Iron exists as oxides, hydroxides, oxy hydroxides, sulphides and carbonates along with iron stained quartz/anatase and mica in kaolin. Kaolin finds extensive applications in paper, paint, rubber, ceramics, plastics etc. One of the highest value additions for kaolin is as pigment in paper and paint industries. The optical properties are important for pigment applications and removal of the iron impurity is very important to improve this property. Extensive research has been carried out on the nature of iron impurities present in kaolin, which leads to the conclusion that iron is present as a part of the kaolinite or ancillary mineral (mica or titania) structure, which can be termed as “structural iron” or as independent iron minerals such as oxides, hydroxides, oxyhydroxides, sulphides and carbonates, which can be termed as “free iron” [1]. The present paper discusses the iron speciation studies carried out on a typical china clay sample collected from Koraput district of Orissa State in the Union of India. Studies have shown that the major impurity mineral species is in “pyritic” (Iron sulphide) form along with other hydroxides, oxyhydoxides and oxides of Iron. Presence of limonite is also observed in the sample. The identification/quantification of the impurity minerals have played a crucial role in the selection / modification and sequentialisation of beneficiation processes and subsequent processing studies have shown that the sample can be value added to ceramic grade.

Statistical optimization and formulation of microalga cultivation medium for improved omega 3 fatty acid production

Microalgae are considered a rich source of high-value metabolites with an array of nutraceutical and pharmaceutical applications.Diferent strategies have been developed for cultivating microalgae at large-scale photobioreactors but high cost and low productivity are the major hurdles.Optimizing the composition of media for the cultivation of microalgae to induce biomass production and high-value metabolite accumulation has been considered as an important factor for sustainable product development.In this study,the efect of plant growth regulators together with basal microalgal cultivation medium on biomass,total lipid,and EPA production was studied using the Plackett–Burman model and Response surface methodology.The traditional one-factor-at-a-time optimization approach is laborious,time-consuming,and requires more experiments which makes the process and analysis more difcult.The Designed PB model was found to be signifcant for biomass(396 mg/L),lipid(254 mg/L),and EPA(5.6%)production with a P value<0.05.The major objective of this study is to formulate a medium for EPA production without compromising the growth properties.Further,we had formulated a new media using RSM to achieve the goal and the signifcant variables selected were NaNO_(3),NaH_(2)PO_(4),and IAA and was found to be signifcant with 16.72%EPA production with a biomass production of 893 mg/L with a P value<0.05.The formulated medium can be used in large-scale cultivation systems which can enhance biomass production as well as the omega 3 fatty acid production in marine microalgae Nannochloropsis oceanica.