Relevant Material Properties

As described in Volume 2IB, Hydrogenated Amorphous Silicon Optical Properties, the absorption coefficient of undoped a-Si H is strongly influenced by the deposition conditions. For example, the optical gap usually increases as the substrate temperature decreases, and this effect has been attributed to an increase in the hydrogen content (Zanzucchi et al., 

Another approach is to alloy the doped layers with nitrogen since it also increases the optical gap (Kurata et al., 1981), but a-Si N H layers have not yet led to high-performance devices. The optical absorption in the doped layers can also be reduced by using microcrystalline Si H layers (Carlson and Smith, 1982). 

For stacked junction solar cells, one would like to tailor the optical properties so that the active material in the first junction has a wide band gap, and the active layers in other junctions have progressively narrower band gaps (see Section 8). As mentioned earlier, either carbon or nitrogen alloying can be used to open the optical gap, while alloying with tin or germanium can reduce the optical gap. Representative optical data for undoped a-Si C H and a-Si Ge H films are shown in Fig. 2. 

In most a-Si H solar cells, a built-in electric field (F) assists in the collection of photogenerated carriers, and efficient collection occurs as long as the drift length (/itF) is significantly larger than the film thickness. Crandall (1982) has shown that the transport in p-i-n cells can be charac- 

Hall effect measurements indicate mobilities of— 10-1 cm2 V-Isec-1 for both electrons (Dresner, 1980) and holes (E resner, 1983). Tiedje et al. (1981) have measured drift mobilities of 1 cm2 V-1 for electrons and 10-3 cm2 V-1 sec-1 for holes. However, Silver et al. (1982) have estimated that the electron mobility is s 100 cm2 V-1 sec-1 by using the reverse recovery technique. 

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Obtain and review the relevant material properties such as flammability and toxicity... 

Whether the product is a new model of an established commodity or a completely new development, a list can be made of the properties the material or group of materials to be employed must possess, and of those that are also most desirable. By reference to the relevant material properties and prices, an analysis can be made to determine the plastic most likely to be suitable from all requirements. 

Relevant material properties as well as process and equipment-specific parameters are completely known for the examples and the solutions proposed. However, the parameters are of a strong abstract nature and are only detailed to the extent needed for the examples. Required calculations were done in accordance with the literature given in the guideline. 

Figure 5.4 Schematic of the geometrical configuration for hydrogen-air flame and sofid fuel. The geometry corresponds to the experimental setup. The initial shape of the HED fuel was a circular arc segment as shown above. The relevant material properties air density = 1.91 kg/m , hydrogen density = 0.0898 kg/m . For the turbulent quantities at the inlet k = (O.OSf/miet) = 9.59 (m/s), = C fc / /(0.03Liniet) = 6360 m /s , jjkt = Cfe = 0.00248 kg/ms. For the fuel sample, m.p. is 450 K, latent heat of fusion is 72.7 J/g. Dimensions in mm. Air inlet velocity 103.3 m/s, hydrogen injection velocity 800 m/s...

We interrupt the procedure to ask some important questions concerning (1) the determination of the characteristic geometric parameter, (2) the setting of all relevant material properties, and (3) the taking into account the gravitational acceleration. 

Setting of all relevant material properties In the preceding relevance list, only the density and the viscosity of the liquid were introduced. The material properties of the gas are of no importance as compared with the physical properties of the liquid. It was also ascertained by measurements that the interfacial tension cr does not effect the stirrer power. Furthennore, measurements [7] revealed that the coalescence behavior of the material system is not affected if aqueous glycerol or cane syrup mixtures are used to increase viscosity in model experiments. 

Here we have conducted experiments to develop an understanding of how the commercial size interacts with the matrix in the glass fiber-matrix interphase. Careful characterization of the mechanical response of the fiber-matrix interphase (interfacial shear strength and failure mode) with measurements of the relevant materials properties (tensile modulus, tensile strength, Poisson s ratio, and toughness) of size/matrix compositions typical of expected interphases has been used to develop a materials perspective of the fiber-sizing-matrix interphase which can be used to explain composite mechanical behavior and which can aid in the formulation of new sizing systems. 

B becomes, at constant g, a pure material number which combines all the relevant material properties at the reference temperature T0. B = idem will therefore define all the appropriate relevant model material properties. 

The more surface- and bulk-related properties of solid materials and their relevance to catalysis are incorporated into an expert system for assisting in catalyst design, the more effective such a system will be. Results and experience may be preserved in the knowledge base. Since such information may be applicable to other reaction types, if some reaction steps or relevant material properties arc common, knowledge bases describing particular fields of interest may even be licensed to third parties, and so become tradable items. 

Figure 26 shows the life-time at 3 temperatures (—10, 20 and 60 °C) for Polymethylmethacrylate (PMMA). As many physical properties of bulk polymers, the life-time may be shifted along the time axis to get one single master curve shown in Fig. 27. It should be noted that none of the other craze properties (Ki(Vj), craze length, craze thickness) can be shifted like the life-time to obtain a master curve. This fact tends to prove that the life-time is a more relevant material property than craze length or craze thickness alone.

The speed and attenuation of sound in a food material are of no practical value in themselves but only as they relate to other relevant material properties. Fundamentally, wavenumber is related to material properties via the Wood equation (5) ... 

This entry gives a brief historical overview and discussion of relevant material properties, followed by a survey of the methods currently used to produce solar cell materials, with an emphasis on silicon. 

The Chow equations, which constitute a large set that is too long and complex to reproduce here, are sometimes more accurate. Both of these sets of general-purpose equations (Halpin-Tsai and Chow) are applicable to many types of multiphase systems including composites, blends, immiscible block copolymers, and semicrystalline polymers. Their application to such systems requires the morphology to be described adequately and reasonable values to be available as input parameters for the relevant material properties of the individual phases. 

R. Blum Design process of a membrane structure and the relevant material properties, in Tensinet-Symposium Designing Tensile Architecture, Brussels, 2003... 

To evaluate the experimental behaviour, relevant material properties should be obtained from suitable specimens cut from lightly stressed parts of the component. Failing this, representative elements may be used for PYamnie untested units made bv the same nrnress and usinn the... 

To evaluate the experimental behaviour of the connection, relevant material properties should be obtained from suitable specimens, cut from parts of the component well away from the connection. Failing this, representative elements such as untested units, made by the same process and using the same materials, may be used. Finally, relevant data may be provided by the manufacturer when there is sufficient experience of the materials and manufacturing process. Where standard components are Joined by the connections, the third option is likely to give the most realistic values. 

Type of analysis Design parameter Relevant material properties... 

The particle concentration of the eluent is normally measured by means of infrared or ultraviolet photometers. Additionally, fluorescence photometer, interferometric measurements (for the refractive index), or mass-spectroscopic methods (e.g. induced coupled plasma mass spectroscopy—ICP-MS, Plathe et al. 2010) are employed. The combination of different detection systems offers an opportunity for a detailed characterisation of multi-component particle systems. Note that the classification by FFF is not ideal and the relevant material properties are not always known moreover, the calibration of FFF is rather difficult. The attribution of particle size to residence time, thus, bears some degree of uncertainty. Recent developments of FFF instrumentation, therefore, include a particle-sizing technique additional to the flow channel and the quantity measurement (usually static and dynamic light scattering, Wyatt 1998 Cho and Hackley 2010). 

Scattering is the dispersal of radiation at an object (particle) that differs in the relevant material properties from its environment (continuous phase). Static scattering experiments record the scattering signal as a function of the angle of observation 0 or—more generally— as function of the scattering vector q ... 

Two basic modes of failure are assumed for the design of pressure vessels. These are (a) elastic failure, governed by the theory of elasticity and (b) plastic failure, governed by the theory of plasticity. Except for thick-walled pressure vessels, elastic failure is assumed. When the material is stretched beyond the elastic limit, excessive plastic deformation or rupture is expected. The relevant material properties are the yield strength and ultimate strength. In real vessels we have a multiaxial stress situation, where the failure is not governed by the individual components of stress but by some combination of all stress components. 

In order to validate the nonlinear viscoelastic model, three uniaxial test cases are analyzed. The results are compared with the laboratory tests conducted on similar specimens by Peretz and Weitsman.(27) The material properties used in the verification analysis are those reported by Becker et The creep data, together with other relevant material properties, are given in Table 3. 

Light is an electromagnetic wave and all its features relevant for ellipsometry can be described within the framework of Maxwell s theory [1]. The relevant material properties are described by the complex dielectric function e or alternatively by the corresponding refractive index n. 

The relevant material property information on the solder composition close to that recommended by dSTEMI (Sn3.9AgO.6Cu) is listed in Table 59.2. 

As standard media, deionized plain water is used. Furthermore, polyvinylpyrrolidone solutions of varying solids concentration and polymer chain lengths are sprayed. The polymer types used for the following experiment are Luvitec K30 (Mw = 4.5 X 10" -5.5 X 10" Da, short chains) and Luvitec K90 (1.2 x 10 -2.0 x 10 Da, long chains). In Table 16.3, relevant material properties are shown. 

Probes are generally made from Si or Si3N4. Some of the relevant materials properties are listed in Table 5. 

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