67 research outputs found
Superhard Phases of Simple Substances and Binary Compounds of the B-C-N-O System: from Diamond to the Latest Results (a Review)
The basic known and hypothetic one- and two-element phases of the B-C-N-O
system (both superhard phases having diamond and boron structures and
precursors to synthesize them) are described. The attention has been given to
the structure, basic mechanical properties, and methods to identify and
characterize the materials. For some phases that have been recently described
in the literature the synthesis conditions at high pressures and temperatures
are indicated.Comment: Review on superhard B-C-N-O phase
Cotton in the new millennium: advances, economics, perceptions and problems
Cotton is the most significant natural fibre and has been a preferred choice of the textile industry and consumers since the industrial revolution began. The share of man-made fibres, both regenerated and synthetic fibres, has grown considerably in recent times but cotton production has also been on the rise and accounts for about half of the fibres used for apparel and textile goods. To cottonâs advantage, the premium attached to the presence of cotton fibre and the general positive consumer perception is well established, however, compared to commodity man-made fibres and high performance fibres, cotton has limitations in terms of its mechanical properties but can help to overcome moisture management issues that arise with performance apparel during active wear.
This issue of Textile Progress aims to:
i. Report on advances in cotton cultivation and processing as well as improvements to conventional cotton cultivation and ginning. The processing of cotton in the textile industry from fibre to finished fabric, cotton and its blends, and their applications in technical textiles are also covered.
ii. Explore the economic impact of cotton in different parts of the world including an overview of global cotton trade.
iii. Examine the environmental perception of cotton fibre and efforts in organic and genetically-modified (GM) cotton production. The topic of naturally-coloured cotton, post-consumer waste is covered and the environmental impacts of cotton cultivation and processing are discussed. Hazardous effects of cultivation, such as the extensive use of pesticides, insecticides and irrigation with fresh water, and consequences of the use of GM cotton and cotton fibres in general on the climate are summarised and the effects of cotton processing on workers are addressed. The potential hazards during cotton cultivation, processing and use are also included.
iv. Examine how the properties of cotton textiles can be enhanced, for example, by improving wrinkle recovery and reducing the flammability of cotton fibre
Mochras borehole revisited: a new global standard for Early Jurassic earth history
The Early Jurassic epoch was a time of extreme environmental
change: there are well-documented examples of rapid
transitions from cold, or even glacial, climates to super
greenhouse events, the latter characterized worldwide by
hugely enhanced organic carbon burial, multiple large isotopic
anomalies, global sea-level change, and mass extinction
(Price, 1999; Hesselbo et al., 2000; Jenkyns, 2010; Korte
and Hesselbo, 2011). These icehouseâgreenhouse events
not only reflect changes in the global climate system but are
also thought to have had significant influence on the evolution
of Jurassic marine biota (e.g. van de Schootbrugge et
al., 2005; Fraguas et al., 2012). Furthermore, the events may
serve as analogues for present-day and future environmental
transitions
Magnesium-induced alterations in the photosynthetic performance and resistance of rice plants infected with Bipolaris oryzae
Disponibilidade hĂdrica relacionada ao conteĂșdo de nitrogĂȘnio e Ă produtividade da alfafa (Medicago sativa L. )
- âŠ