Flax (Linum usitatissimum L.) is an important oil seed crop that is mostly cultivated in temperate climates. In addition to many commercial applications, flax is also used as a fibrous species or for livestock feed (animal fodder). For the last 40 years, flax has been used as a phytoremediation tool for the remediation of different heavy metals, particularly for phytoextraction when cultivated on metal contaminated soils. Among different fibrous crops (hemp, jute, ramie, and kenaf), flax represents the most economically important species and the majority of studies on metal contaminated soil for the phytoextraction of heavy metals have been conducted using flax. Therefore, a comprehensive review is needed for a better understanding of the phytoremediation potential of flax when grown in metal contaminated soil. This review describes the existing studies related to the phytoremediation potential of flax in different mediums such as soil and water. After phytoremediation, flax has the potential to be used for additional purposes such as linseed oil, fiber, and important livestock feed. This review also describes the phytoremediation potential of flax when grown in metal contaminated soil. Furthermore, techniques and methods to increase plant growth and biomass are also discussed in this work. However, future research is needed for a better understanding of the physiology, biochemistry, anatomy, and molecular biology of flax for increasing its pollutant removal efficiency.

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The spherical curvature induced by pentagons in corannulenes and hexagonal sheets is shown to be the basic constituent that controls the growth of fullerenes and single-walled carbon nanotubes (SWNTs) in soot forming and carbon vapour environments. Formation of the initial ring of five or six atoms is the essential step which with the addition of further pentagons and hexagons determines whether a spinning fullerene is to be formed or the cap that lifts up and leads to the formation of an SWNT. A continuum elastic model is developed to determine the criteria for the growth of these structures. The observed dominance of the growth of 14 Å diameter armchair SWNTs in sooting and carbonaceous environments is explained by using the nanoelastic model of C shells.

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Laboratory formation of large carbon clusters C m (m ≤ 10 4 ) in carbonaceous plasmas has been studied by using an especially designed ion source. Carbon is introduced into the glow discharge plasma by sputtering of the graphite electrode. Soot dominated plasma is created whose constituents are carbon clusters. It produces and recycles cluster containing plasma. Regenerative sooting plasma creates the environment in which the entire spectrum of clusters that contain the linear chains, rings and fullerenes. Velocity spectra of the extracted clusters have been measured with an ExB filter. These spectra indicate and identify the mechanisms operating in the soot.During Experiments with regenerative sooting plasmas [1] we have observed that carbon cluster C m synthesis is the most prominent carbon accretion mechanism in the glow discharge of a graphite hollow cathode. We have attempted to create conditions similar to those found in typical carbon stars [2,3] leading to C synthesis into structures ascribed to be spherical graphite grains.In most cool stars pressures of the order of 10

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