Marine Oil spills have become a serious environmental problem, and contribute to severe impacts and economic losses. Fast and efficient cleanup of oil from marine environment is vital. The use of sorbents is one of the most efficient techniques in removing oil from water. In this work, pure polypropylene (PP) ultrafine fibers with 2 μm diameter were prepared by air assisted melt electrospinning device to be used as oil sorbent. Two fiber samples were used in this study, fluffy, cotton like appearance and oriented, cloth like appearance with different porosities. The influence of temperature change on oil/water mixture was studied. Fluffy fibers showed a better performance in sorption capacity. Results indicated that change in temperature was an important factor in determining the sorption capacity of the fibers. Additionally, in contrast to solution electrospinning, melt electrospinning is safer, cost effective and …

Six Hakea species varying greatly in seed size were selected for cotyledon damage experiments. The

growth of seedlings with cotyledons partially or completely removed was monitored over 90 days. All

seedlings perished by the fifth week when both cotyledons were removed irrespective of seed size.

Partial removal of cotyledons caused a significant delay in the emergence of the first leaf, and reduction

in root and shoot growth of the large-seeded species. The growth of seedlings of small-seeded species

was less impacted by cotyledon damage. The rate of survival, root and shoot lengths and dry biomass

of the seedlings were determined after 90 days. When seedlings were treated with balanced nutrient

solutions following removal of the cotyledons, survival was 95–98%, but 0% when supplied with

nutrient solutions lacking N or P or with water only. The addition of a balanced nutrient solution failed

to restore complete growth of any species, but the rate of root elongation for the small-seeded species

was maintained. Cotyledons provide nutrients to support early growth of Hakea seedlings, but other

physiological roles for the cotyledons are also implicated. In conclusion, small-seeded Hakea species can

tolerate cotyledons loss better than large-seeded species..

Seed size is a key functional trait that affects plant fitness at the seedling stage and may vary greatly with species fruit size, growth form and fecundity. Using structural equation modelling (SEM) and correlated trait evolution analysis, we investigated the interaction network between seed size and fecundity, postfire regeneration strategy, fruit size, plant height and serotiny (on-plant seed storage) among 82 species of the woody shrub genus, Hakea, with a wide spectrum of seed sizes (2–500 mg). Seed size is negatively correlated with fecundity, while fire-killed species (nonsprouters) produce more seeds than resprouters though they are of similar size. Seed size is unrelated to plant height and level of serotiny while it scales allometrically with fruit size. A strong phylogenetic signal in seed size revealed phylogenetic constraints on seed size variation in Hakea. Our analyses suggest a causal relationship between seed size, fecundity and postfire regeneration strategy in Hakea. These results demonstrate that fruit size, fecundity and evolutionary history have had most control over seed size variation among Hakea species

New composite polyvinyl alcohol (PVA)/polypropylene (PP) membranes were prepared by combining both solution electrospinning and melt electrospinning methods. Self‐designed and made needleless melt electrospinning device was used to fabricate PP membranes which acted as the support layer. PVA membrane on the surface was fabricated via solution electrospinning. The electrospun PVA/PP composite membranes were characterized by the pore size distribution, pure water flux, and rejection ratio, then compared with general composite membranes. Characterizations revealed that the fiber diameter of solution electrospun PVA membrane and melt electrospun PP membrane were 0.171 ± 0.027 and 2.24 ± 0.33 μm, respectively, and the average pore size was 0.832 μm and 27.29 μm, which was much smaller than the nonwoven membrane. The rejection ratio to the 500 nm particles of the PVA/PP …

Solventless melt electrospinning which allows mass production is substantially safe. It can produce fibres of hundreds of nanometres, one order of magnitude lower than that of conventional melt-blown spinning. In this paper, a comparison between different technologies producing ultra-fine fibre reveals the advancement of melt electrospinning method using umbellate spinneret for ultra-fine fibre mass production. Some typical industrial polymer materials was also spun using melt electrospinng method, including biodegradable materials like polylactic acid and polycaprolactone (PCL), which may contribute to some interesting applications. In addition, a machine for mass production is also proposed. Finally, proposition of the industrialisation of ultra-fine fibre by melt electrospinning is discussed.

Ultrafine polypropylene (PP) fibers as oil sorbents were fabricated via a needleless melt‐electrospinning device and were characterized by scanning electron microscopy and contact‐angle analysis. PP fibers of various diameters and porosities were obtained by the manipulation of the applied electrical field. The effects of the fiber diameter and porosity on the oil‐sorption capacity and oil‐retention behavior were investigated. The experimental results demonstrate that for fiber diameter on the microscale, the porosity played a paramount role in determining the oil‐sorption capacities. The maximum oil‐sorption capacity of the resulting PP fibers with regard to motor oil and peanut oil were 129 and 80 g/g, respectively; these values were approximately six to seven times that of commercial PP nonwoven fabricated through the melt‐blown method. In addition, even after seven sorption/desorption cycles, the oil‐sorption 

In this study, polypropylene was mixed with three different pore-forming agents (nanometer cal-cium carbonate, paraffin and inorganic hybrid salts) to form three blended systems which were used to pro-duce composite fibers by self-made melt differential electrospinning device. Polypropylene fibers withrough surface and microporous were prepared after removing above-mentioned pore-forming agents. Thesurface morphological structures of these polypropylene fibers were characterized. Results showed that theaverage diameter of polypropylene-nanometer calcium carbonate composite fibers (8.22 μm), polypropylene-paraffin composite fibers (8.67 μm) and polypropylene-inorganic hybrid salts composites fiber (6.08 μm) wasless than pure polypropylene fibers (12.10 μm); the diameter of composite fibers was not reduced with theincreasing of melt index; polypropylene fibers without nanometer calcium carbonate comprised microporoushaving different sizes and uneven distribution, polypropylene fibers without paraffin had rough surface andstrip or bulk dents, polypropylene fibers without inorganic hybrid salts comprised microporous having rela-tively small sizes and even distribution. These three polypropylene fibers were all able to increase the hydro-philicity or hydrophobicity of materials. Furthermore, the number of Taylor cone was increased by using as-sistant air flow. Taylor cone contributed to the stability of jet flow and the refining of composite fibers whenTaylor cone increased to a certain number.

        Three plant species are new recored form Libya

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