The two most important environmental hazards faced by humankind today are air pollution and global warming. Both have a direct link with our current overdependence on fossil fuels. Pollutants produced from combustion of hydrocarbons now cause even more health problems due to the urbanization of world population
DMFC (Direct Methanol Fuel Cell) – pin nhiên liệu dùng methanol trực tiếp Dù công nghệ vẫn mới chỉ chập chững ở những bước ban đầu nhưng đã thể hiện được một số thành công trong những ứng dụng như điện thoại di động và máy tính xách tay (laptop), đem lại triển vọng đầy tiềm năng cho tương lai. DMFC tương tự như PEMFC ở chỗ chất điệnphân là polymer và điện tích vận chuyển là ion hydrogen (proton)....
This is a book about coal gasification and its related technologies. The relationship
between these technologies is shown in Figure 0.1. The gasification process begins with
a viable feedstock. In this book, we focus on one of those feedstocks that must go
through the gasification process, coal.
The creation of Trichet bonds will result in various advantages both in comparison to the present
unstable situation and other proposed solutions. First, the long duration of Trichet bonds will
eliminate the immediate crisis caused by short term expiration of significant amounts of debt
which is looming over Greece, Ireland, Portugal, Spain and possibly other EU countries. Second,
the guarantee of the principal with the zero-coupon ECB bond collateral increases the quality of
the Trichet Bonds compared to existing sovereign debt.
This could be fortuitous at modest scales because oxygen is relatively costly (Consonni
and Larson 1994a). However, for the production of methanol from biomass,
the use of air increases the volume of inert (N
) gas that would have to be carried
through all the downstream reactors. Therefore, the use of oxygen thus improves
the economics of synthesis gas processing. Air-fired, directly heated gasifiers are
considered not to be suitable before methanol production.
This gasifier produces a CO
The presence of chlorine in alternative fuels (e.g., sewage sludge, municipal solid waste
or incineration ash, chlorinated biomass,) has both direct and indirect implications on
cement kiln emissions and performance. Methods have been developed to properly
manage chlorine and its potential implications – but it is important that these implications
be recognized and managed. Trace levels of chlorine in feed materials can lead to the
formation of acidic gases such as hydrogen chloride (HCl) and hydrogen fluoride (HF)
The activity of the digestiveb-glycosidase fromSpodoptera
frugiperda (Sfbgly50, pH optimum 6.2) depends on E399
(pKa¼4.9; catalytic nucleophile) and E187 (pKa¼7.5;
catalytic proton donor). Homology modelling of the
Sfbgly50 active site confirms that R97 and Y331 form
hydrogen bonds with E399. Site-directed mutagenesis
showed that the substitution of R97 bymethionine or lysine
increased the E399 pKa
by 0.6 or 0.8 units, respectively,
shifting the pH optima of these mutants to 6.5.