Forests, depletion

There has been an increasing awareness of the deleterious environmental impacts associated with the presence of sulphur dioxide and the nitrogen oxides in power station and factory stack emissions. This resulting acid rain has been responsible for the quite dramatic forest depletion and the... 

As much as 6000 years ago, charcoal was the preferred fuel for smelting copper. After the invention of the blast furnace around 1400 AD, charcoal was used extensively throughout Europe for iron smelting. By the eighteenth century, forest depletion led to a preference for coke (a coal-based form of charcoal) as an alternative fuel. 

Plastics are also energy-efficient compared with traditional materials [1]. It takes twice the weight of paper to effectively protect goods than in the case of polyethylene and if all the plastics currently used in packaging were to be replaced by paper, the effect on the environment would be catastrophic in terms of forest depletion, increased energy utilisation and damage to the environment [2,3]. This ecologically important characteristic of the polyolefins will be discussed in more detail in Section 4. 

With rising tuition costs, depleted forests, and students aching backs, the answer is obvious. The cartoon on this page illustrates one of our reasons. We remained steadfast in our belief that it should be possible to cover a text completely (or at least almost completely) in a two-semester course. The students justifiably ask why they have to pay for 1000-page books with stuff that is never covered in the course. We still do not have a good reason, so a 600-plus-page book was the aim for the sixth edition. 

Plastic papers have been developed as substitutes for these cellulose papers, but the economics are poor since the plastics are more costly. Also plastics weigh tend to be more than the cellulose paper. So it is possible to save the forests (does it really need it since it is easy to replenish as the past century proved). Did you know when America was discovered and up until the end of the 19th century there were literally no trees when compared to those in USA now and any depletion can be replaced and even expanded (as one knows who is learned in this field). Another factor related to this tree myth is that when the world started its Computerized World it was said by many that much less paper would be required. Of course much more is used and required. 

Assessment of the regional extent of forest ecosystems sensitive to calcium depletion will be possible using a combination of data obtained from watershed studies,... 

Thirgood, J. V. 1981. Man and the Mediterranean Forest A History of Resource Depletion. Academic Press, London, New York, 194 p. 

The effects of acid rain can be seen in lakes and streams, in forests, and on all kinds of structures. The lowered pH kills fish eggs, fish, and many other organisms that live in lakes and streams. In forests, the acid can kill the leaves and needles of trees. It damages the soil by depleting it of nutrients, which stunts plant growth. Acid rain also eats away at the surfaces of buildings and other structures. Structures made of marble and other calcium-containing stone are particularly sensitive to acid rain. 

Hydrochloric acid is used in numerous applications, but it is generally obtained indirectly as a by-product in other chemical processes. The first large-scale production of hydrochloric acid resulted from the mass production of alkalis such as sodium carbonate (Na C ) and potassium carbonate (potash, K2C03). The depletion of European forests and international disputes made the availability of alkali salts increasingly uncertain during the latter part of the 18th century. This prompted the French Academy of Science to offer a reward to anyone who could find a method to produce soda ash from common salt (NaCl). Nicholas LeBlanc (1743—1806) was credited with solving the problem. LeBlanc proposed a procedure in 1783 and a plant based on LeBlanc s method was opened in 1791. LeBlanc s method uses sulfuric acid and common salt... 

Evidence of the importance of as yet unanticipated information on naturally occurring agents, the U.S. Department of Agriculture in late 1991 granted Bristol-Myers Squibb Company the authority to harvest the bark of Pacific yew trees in federal forests for the chemical taxol, a potential anticancer drug. Soon after other natural and synthetic precursors were developed so that the natural sources would not be depleted. 

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