Stable negative ions containing up to sixteen silicon atoms have been measured by mass spectromettry in RF power-modulated silane plasmas for amorphous silicon deposition. These hydrogenated silicon cluster ions reach much higher masses than the positive ions, which have no more than six silicon atoms. This supports the view that negative ions are the precursors to particulate formation in silane plasmas. The time-dependent fluxes d positive and negative ions from the plasma are shown with a 5 p s time resolution. Possible cluster reaction sequences are discussed and the effect of visible light on the negative ion signal i s commented upon.

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The physicochemical properties of liquid biofuels of different types (bioalcohols, biodiesel, etc.) in comparison to the same characteristics of petroleum fuels were examined. The advantages and disadvantages of biofuels with respect to these characteristics were demonstrated.

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A theoretical estimate is made of the thermal combustion of a proposed liquid biofuel on the basis of extracted substances obtained from wooden wastes. The authors have performed the most complete qualitative and quantitative composition, where they have calculated the lower heat of combustion for components. A comparison has been put for burning doing with traditional petroleum fuels.The reserves of fossil fuels, namely oils and natural gases, are restricted, and they confirm confutes for millions of years [5]. In this connection, interest attaches to alternative forms of liquid and gaseous fuels [1-21] derived from plant biomasses: renewed sources of organic raw material [1][2][3][4], and considerable stores of this contain liquid of nature [5]. Various forms of biofuel are proposed: alcohols (biomethanol and bioethanol) [6-10], plant oils (biodiesel) [9][10][11][12][13][14][15][16][17], and sources of these provided by maize, beetroots, sugar canes, wheat, rice, rapes, soya, and so on. However, fuel problems result in other direct contests: direct competition with the use of nutrition products, and also foods for agricultural animals. The outlet from such situation is to obtain liquid and gaseous fuels from nonfood plant raw materials.In Russia, they prepare every week about 150 million tonnes of wooden material [18][19][20][21]. When this is processed, there is a considerable amount of forming wastes [22], which can be subject in waste-free extract processing to obtain low-molecular organic substances, in particular wooden liquid suitable for use as motor fuel, and also as octane-raising additives to gasoline (previously such additives have been used in aviation [20]). The most important feature of extractive processing is of nondestructive character. In the process of such alteration of the structure and composition of the cellular walls of wood there are no major changes, where the products are processed to obtain thorough procedures, and also evidence from natural wood [21]. It is possible to extract valuable products and work with numerous wastes, such as pines, tree barks, crown branches, leaves, pines, and so on [18][19][20][21].The heat of combustion [23-28] is one of the basic parameters governing the suitability of any product as a fuel for internal combustion engines. The purpose of this work is to provide a theoretical estimate of the heat of 444 Table 1 Extracted substance Gross formulaContent in fuel mixture, wt.%

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