CLARINET

Many policies and practices have been adopted by European countries for the management of contaminated sites. Information about the various national polices, the technical approaches for risk assessment, and the progress of rehabilitation activities in Europe has been compiled in the framework of two European networks—CARACS (Concerted Action for Risk Assessment for Contaminated Sites) and CLARINET (Contaminated Land Rehabilitation Network for Environmental Technologies)—which were funded by the European Commission. A detailed description of European national policies can be found in relevant publications2 3 and in the CLARINET website (http //www.clarinet.at). 

Vic, E.A. and Bardos, P., Remediation of Contaminated Land. Technology Implementation in Europe, Federal Environmental Agency, Austria. CLARINET Report, available at www.clarinet.at, 2002. With permission. 

As musicians know, it is the relative intensities of the various members of the overtone series that determine the timbre or tone quality of sound. It is easy to distinguish the sound of a flute from that of the clarinet, although the listener may not know why. The sound of the flute has a relatively intense first overtone, while the boundary conditions imposed on the vibrating air column in the clarinet result in the suppression of all odd overtones. Such phenomena are of course much easier to visualize on a stringed instrument Ask a violinist for a demonstration of the natural harmonics of a given string. 

Obataya, E. (1999). Suitability of acetylated woods for clarinet reed. Journal of Wood Science, 45(2), 106-112. 

This signal representation with only odd harmonics is an approximate model for a clarinet as with a uniform tube closed at one end and open at the other. In order to capture the time-varying envelope and bandwidth, one applies a A(n ) with a fast attack and slow release, and also makes the modulation index I(n ) inversely proportional to this envelope, thus emulating the decreasing bandwidth as a function of time. 

The theory of the single reed is described in [McIntyre et al., 1983]. In the digital waveguide clarinet model described below [Smith, 1986a], the reed is modeled as... 

A simplified diagram of the clarinet mouthpiece is shown in Fig. 10.18. The pressure in the mouth is assumed to be a constant value pm, and the bore pressure pb is defined located at the mouthpiece. Any pressure drop p = pm - Pb across the mouthpiece causes a flow um into the mouthpiece through the reed-aperture impedance Rm(pa ) which changes as a function of pa since the reed position is affected by p. ... 

Another approach is to replace the table-lookup contents by a piecewise polynomial approximation. While less general, good results have been obtained in practice [Cook, 1992, Cook, 1996], For example, one of the SynthBuilder clarinet patches employs this technique using a cubic polynomial [Porcaro et al., 1995],... 

Practical Details. To finish off the clarinet example, the remaining details of the SynthBuilder clarinet patch Clarinet2.sb are described. 

CDC 6000, 210 COPAS, 217 Caruso, 134 Cepstral distance, 30 Chaos measure, 61 Characteristic impedance, 433 Chipmunk effect, 322 Cholesky decomposition, 148 Chorusing, 298, 303 Circulant matrix, 126 Clarinet synthesis, 455 Clarity index, 98 Clicks (See Restoration)... 

Simple, qualitatively chosen reed table for the digital waveguide clarinet.461... 

Today musicians take for granted that their instruments are polyphonic. Early analog instruments were monophonic, that is, they only could produce one note a time like a clarinet, which can only produce one note at a time. Musicians used to pianos expected to have arbitrary polyphony available since with a piano, a player could conceivably press up to all 88 keys simultaneously. 

If the bore is cylindrical, as in the clarinet, it can be modeled quite simply using a bidirectional delay line [Smith, 1986a, Hirschman, 1991], If the bore is conical, such as in a saxophone, it can still be modeled as a bidirectional delay line, but interfacing to it is slightly more complex, especially at the mouthpiece [Benade, 1988, Gilbert et al., 1990, Smith, 1991, Valimaki and Karjalainen, 1994a, Scavone, 1997] Because the main control variable for the instrument is air pressure in the mouth at the reed, it is convenient to choose pressure wave variables. 

Figure 10.17 Waveguide model of a single-reed, cylindrical-bore woodwind, such as a clarinet.

A diagram of the basic clarinet model is shown in Fig. 10.17. The delay-lines carry left-going and right-going pressure samples p and (respectively) which sample the traveling pressure-wave components within the bore. 

Smith and Scavone, 1997] Smith, J. O. and Scavone, G. (1997). The One-Filter Keefe Clarinet Tonehole. In Proc. IEEE Workshop Appl. of Signal Processing to Audio and Acoustics, Mohonk Mountain House, New Paltz, NY. 

Colour Index International, Third Edition, 1999, CD-Rom, Clarinet Systems Ltd., SDC and AATCC, 1999. 

African blackwood is another hard black wood that is commonly used in musical instruments. This wood has a higher natural sheen than ebony, and is the preferred choice for making the tubes for oboes, clarinets, and other woodwinds. 

International harmonization of soil quality standards (SQSs) has been discussed in the CARACAS (Concerted Action on Risk Assessment for Contaminated Sites in the European Union, 1995 to 1998) and CLARINET (Contaminated Land Rehabilitation Network for Environmental Technologies, 1998 to 2001) concerted actions (Vegter et al. 2003), and a form of the Soil Framework Directive is still under review by member states in the European Union, so the present guidance is both timely and relevant. 

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