Sound grains

In order to gain a better understanding of granular synthesis it is necessary to comprehend the concept of sound grains and their relationship to our auditory capacity. This notion is largely based upon a sound representation method published in 1947, in a paper by the famous British physicist Dennis Gabor (1947). Until then the representation of the inner structure of sounds was chiefly based upon Fourier s analysis technique and Helmholtz s musical acoustics (Helmholtz, 1885). 

As far as the idea of sound grains is concerned, any synthesiser producing rapid sequences of short sounds may be considered as a granular synthesiser. However, there are important issues to consider when designing a granular synthesis instrument. Three general approaches to the technique are presented as follows. 

Each sound grain produced by Chaosynth is composed of several spectral components. Each component is a waveform produced by a digital oscillator which needs two parameters to function frequency (Hz) and amplitude (dB). In Chaosynth, the oscillators can produce various types of waveforms such as sinusoid, square, sawtooth, and band-limited noise. The CA control the frequency and duration values of each grain, but the amplitude values are set up by the user beforehand via Chaosynth s Oscillators panel. The system can, however, interpolate between two different amplitude settings in order to render sound morphing effects. 

Figure 5.11 Each snapshot of the cellular automaton produces a sound grain. Note that this is only a schematic representation, as the grains displayed here do not actually correspond to these particular...

Pulsar synthesis, as recently proposed by Curtis Roads (2001), shares the same fundamental principles of granular synthesis. The main difference is that the concept of sound grains is replaced by the notion of pulsars. In essence, a pulsar is a sound grain with a variable duty cycle an idea inspired by an analog synthesis effect known as pulse-width-modulation (PWM). More specifically, a pulsar consists of a waveform w (or pulsaret) of duration d followed by a silent portion s (Figure 5.12). The period p of a pulsar is therefore given by the sum of H7 + s, and d corresponds to the duration of its duty cycle. The frequency of a stream of pulsars with period p is calculated as 1/pHz. 

Describe the typical way sound grains with adequate moisture content can deteriorate throughout prolonged storage. 

Primary insect Kind of insect that has the capability of damaging sound or healthy grains. They possess a strong mouth system capable of perforating or boring into sound grains for feeding or reproduction purposes. 

Secondary insect Kind of insect that attacks damaged kernels or nulled and processed products but is not capable of damaging sound grains. 

The Fe, Co, and Ni deposits are extremely fine grained at high current density and pH. Electroless nickel, cobalt, and nickel—cobalt alloy plating from fluoroborate-containing baths yields a deposit of superior corrosion resistance, low stress, and excellent hardenabiUty (114). Lead is plated alone or ia combination with tin, iadium, and antimony (115). Sound iasulators are made as lead—plastic laminates by electrolyticaHy coating Pb from a fluoroborate bath to 0.5 mm on a copper-coated nylon or polypropylene film (116) (see Insulation, acoustic). Steel plates can be simultaneously electrocoated with lead and poly(tetrafluoroethylene) (117). Solder is plated ia solutioas containing Pb(Bp4)2 and Sn(Bp4)2 thus the lustrous solder-plated object is coated with a Pb—Sn alloy (118). 

Filter Beds. The sprinkling filter beds of sewage plants are composed of closely screened mineral aggregate of 38—64 mm or 51—76 mm that meet a severe soundness test. Much of this requirement is suppHed by dense, fine-grained, hard limestone and dolomite. 

Selenium acts as a grain refiner in lead antimony alloys (114,115). The addition of 0.02% Se to a 2.5% antimonial lead alloy yields a sound casting having a fine-grain stmcture. Battery grids produced from this alloy permit the manufacture of low maintenance and maintenance-free lead—acid batteries with an insignificant loss of electrolyte and good performance stability. 

The carbon-containing catalyst was treated by ultra-sound (US) in acetone at different conditions. The power of US treatment, and the time and regime (constant or pulsed), were varied. Even the weakest treatments made it possible to extract the nanotubules from the catalyst. With the increase of the time and the power of treatment the amount of extracted carbon increased. However, we noticed limitations of this method of purification. The quantity of carbon species separated from the substrate was no more than 10% from all deposited carbon after the most powerful treatment. Moreover, the increase of power led to the partial destruction of silica grains, which were then extracted with the tubules. As a result, even in the optimal conditions the final product was never completely free of silica (Fig. 12). 

Figure 5. Carbonyl group labeling. Application of the TAg sequence. 5A Control = TAg on sound wood. 5B silver grain deposits correspond to the carbonyl groups created by the fungus. (ML + PW = middle lamella + primary wall Si and S2 = outer and middle layers of the secondary wall, respectively.)...

Wasowicz, E., Kaminski, E., Kollmannsberger, H., Nitz, S., Berger, R.G., Drawer , F. (1988) Volatile components of sound and musty wheat grains. Chem. Mikrobiol. Techno Lebensm. 11 161-168. 

---