摘要:

In the present investigation the effects of carbonization conditions (temperature and heating rate) on the mechanical properties (such as crushing and impact strengths and shatter index) of acacia and eucalyptus wood chars have been determined. The crushing and impact strengths of both the acacia and eucalyptus wood chars (made by slow carbonization) decreased with increase of preparation temperature up to 600 degrees C, followed by an increase thereafter. These wood chars showed a continuous increase in shatter index values with carbonization temperature. In contrast to slow carbonization (heating rate 4 degrees C min -1), rapid carbonization (heating rate 30 degrees C min -1) yielded chars of lower crushing strengths. Slowly carbonized eucalyptus wood gave chars of superior crushing and impact strengths than those produced from acacia wood under the same carbonization conditions. The crushing and impact strengths of these wood chars, in general, have shown an increase with increase in their apparent density. The crushing strength of cubic-shaped wood char decreased with increase in size.

ISSN:0090-8312    

DOI:10.1080/00908319950014425

出版商:Informa UK Ltd    

年代:1999

数据来源: Taylor

摘要:

This article presents a new approach to developing proper strategies for multicriteria medium- and long-term power generation expansion planning. The desired strategies present a predetermined number of appropriate planning alternatives, which should be selected from a vast initial set in accordance with the given multiple criteria. These multiple criteria, caused by considering environmental criteria (such as SO2, NOx, and particulate emissions minimization) together with economic and other criteria, make multicriteria analysis a cornerstone of the proposed approach. The proposed multicriteria analysis includes determining a criteria assessment vector for each initial alternative and multicriteria optimization of a set of such initial criteria assessment vectors. The basic issue of this article is to reflect development of calculation models for the environmental criteria (to create the criteria assessment vectors) together with appropriate environmental investigations. Suitable solution methodology and software, applied to the conditions prevailing in Israel, have been developed for the proposed approach.

ISSN:0090-8312    

DOI:10.1080/00908319950014434

出版商:Informa UK Ltd    

年代:1999

数据来源: Taylor

摘要:

In Turkey illegal cutting takes place, which cannot be controlled. Legal cuttings have also been done by several state forest enterprises. As a result, the amount of wood raw material produced by forest enterprises legally and by forest villagers illegally has exceeded the potential capacity of the forest. According to the research related to Macka and other Turkish state forests, the state forests have been decreasing day by day. This is because the amount of wood raw material taken from the forests has exceeded the production potential of the forest. That study concluded that the Macka and other Turkish forests will be exhausted after 64 and 67 years, respectively. This study also examined both establishing and exploiting energy forests near the forest villages and producing fuel briquettes manufactured using the residues of agriculture, forestry, and stock breeding to diminish the demand for illegal fuel wood cutting from the state forests.

ISSN:0090-8312    

DOI:10.1080/00908319950014443

出版商:Informa UK Ltd    

年代:1999

数据来源: Taylor

摘要:

Approximately 58,000 indoor radon measurements are available for homes in Maryland. A comparative study between compilations of activated-charcoal and alpha-track measurements of indoor radon in zip-code-size geographic areas indi cated that both of these methods are useful and are equally able to estimate regional indoor radon. Indoor radon measurements compiled according to zip code areas can be used to create state-size radon hazard maps. In Maryland the area with the highest indoor radon (mostly composed of zip code areas that average over 8 pCi/L) is the western half of the Piedmont Province and the eastern side of the Coastal Plain Province. The eastern half of the Piedmont and the eastern half of the Valley and Ridge mostly have intermediate and high indoor radon levels (4-8 and > 8 pCi/L). The Blue Ridge, western side of the Valley and Ridge, and Plateau Province each has relatively few zip code areas, but the data suggest a range from low to high indoor radon levels. The western side of the Coastal Plain has the lowest indoor radon (most of the zip code areas average less than 4 pCi/L).

ISSN:0090-8312    

DOI:10.1080/00908319950014452

出版商:Informa UK Ltd    

年代:1999

数据来源: Taylor

摘要:

Several thousand indoor radon measurements have been obtained for homes in northern Virginia. Compilations of these data according to the geologic units under the homes show that some units have relatively high or relatively low median indoor radon levels, and that these differences persist through all four seasons. An attempt to determine if soil radon and soil permeabilitycould yield similar results, in terms of relative indoor radon, was not successful. Care should be taken in using such measurements to characterize the potential for radon problems in established communities and in areas of as-yet undeveloped property.

ISSN:0090-8312    

DOI:10.1080/00908319950014461

出版商:Informa UK Ltd    

年代:1999

数据来源: Taylor

摘要:

This article examines those chemicals that are listed in either environmental laws or regulations. Its objective is to help readers determine which laws regulate what types of chemicals and which types of chemicals are regulated by what laws. It is multimedia in scope, describing the various chemicals that are regulated in the different media (i.e., air, water, or land).

ISSN:0090-8312    

DOI:10.1080/00908319950014470

出版商:Informa UK Ltd    

年代:1999

数据来源: Taylor

摘要:

With rising energy costs and an increasing demand for renewable energy sources, thermal energy storage (TES) systems are becoming an interesting option. TES is a key component of any successful thermal system and a good TES should allow minimum thermal energy losses. In this study, various ways of thermal conservation are outlined and discussed, both theoretical and experimental. In this respect, the TES systems and their practical applications and some selection criteria have also been given.

ISSN:0090-8312    

DOI:10.1080/00908319950014489

出版商:Informa UK Ltd    

年代:1999

数据来源: Taylor

摘要:

The relationship between energy and the use of conservation tillage is of special importance in addressing concerns about the impact of agricultural production on the environment in the United States. It is the subject of this paper. After establishing that a relationship exists between the price of energy and the use of conservation tillage via Granger causality, the relationship is quantified. It is shown that while the real price of crude oil, the proxy used for the price of energy, does not affect the rate of adoption of conservation tillage, it does impact the extent to which it is used. Finally, there is no structural instability in the relationship between the relative use of conservation tillage and the real price of crude oil over the period 1963 to 1997.

ISSN:0090-8312    

DOI:10.1080/00908319950014498

出版商:Informa UK Ltd    

年代:1999

数据来源: Taylor