Impact index

The EPS system was initially developed to be used within the product development process as a tool to help assess the environmental performance of products. The system is based on LCA (Life Cycle Assessment) methodology and uses inventory data (kg of substance A), characterization factors (impact/kg of substance X) and weighting factors (cost/impacts) to calculate the external costs or values of a product. By multiplying the characterization factor with the weighting factor, an impact index is obtained (cost/kg of substance X) which describe the cost/values related to the emission per use of a kg of a certain substance. 

At the same time, the current impact index of U.S. technology—as measured by citations of U.S. patents by other patents—has strengthened in all areas, including the chemical sciences. A closer look at the data for chemical sciences shows that the U.S. impact is increasing, while Germany s is flat and Japan s is decreasing significantly. 

Sparks Companies Inc., The Rendering Industry Economic Impact of Future Feeding Regulations, report prepared for the National Renderers Association (2001). Available http //www.renderers.org/economic impact/index.htm. 

For comparison purposes, a simple impact index can be calculated for each process or parameter measured ... 

FIGURE 15.12 Schematic showing the concept of impact index as a function of distance from inflow (or impact). (Reddy et al., 1999.)... 

Impact Index Values for Select Biogeochemical Indicators Measured in Detritus and Soil Layers at the Impacted Site and Interior Reference Site... 

FIGURE 15.13 Impact index values for a range of biogeochemical indicators and processes measured in detrital/floc layer of the Everglades. 

Zhao et al. describe the concepts and mathematical foundations for PARIS II software that designs solvent mixtures based on optimal solvent properties. The solvent property categories include performance requirements and environmental requirements (a VOC index and an environmental impacts index), and are based on general, dynamic, and equilibrium properties. The chapter by Nelson contains... 

MFCA objective function can be considered as an environmental impact index. While environmental negative impact reduces, green productivity increases. Designing of a measurement system that represents the relationships between green productivity and MFCA initiatives could be new area for researching. 

Citation Searching. In the scholarly Hterature, authors cite earHer pubHcations that relate to the work being reported, thus a subject relationship exists between the citing and cited Hterature. This relationship has formed the basis for the Science Citation Index and related products, developed by the Institute for Scientific Information. Known as Scisearch in its on-line version, the Science Citation Index has become an important information retrieval tool in the second half of the twentieth century. It has been used for straightforward subject searching, in which mode it complements traditional indexed databases and indexes. It has also become a popular tool for hihliometric studies of various sorts, such as attempts to measure the relative impact of research carried out by different individuals or organizations, or the relative impact of pubHcations in different journals. 

DMPPO—polystyrene blends, because of the inherent flame resistance of the DMPPO component (oxygen index ca 29.5), can be made flame retardant without the use of halogenated additives that tend to lower impact strength and melt stabiUty in other polymers. Approximately one-half of total Noryl sales volume is in flame-retarded grades, ie, VO or VI in a 1.6-mm section (UL-94). 

Besides appHcation as heat-resistant molding powders for electronic and other appHcations, DAIP copolymers have been proposed for optical apphcations. Lenses of high impact resistance contain 50% DAIP, 20% benzyl methacrylate, and larger amounts of CR-39 (59). A lens of refractive index 71- = 1.569 andlow dispersion can be cast from phenyl methacrylate, DAIP, and isopropyl peroxide (60). Lenses of better impact properties can be obtained by modifying DAIP with aHyl benzoate (61). 

Hplc techniques are used to routinely separate and quantify less volatile compounds. The hplc columns used to affect this separation are selected based on the constituents of interest. They are typically reverse phase or anion exchange in nature. The constituents routinely assayed in this type of analysis are those high in molecular weight or low in volatility. Specific compounds of interest include wood sugars, vanillin, and tannin complexes. The most common types of hplc detectors employed in the analysis of distilled spirits are the refractive index detector and the ultraviolet detector. Additionally, the recent introduction of the photodiode array detector is making a significant impact in the analysis of distilled spirits. 

The effects of rank on both compressive and impact strength have been studied, and usual minima were found at 20—25% dry, ash-free volatile matter (88—90 wt % carbon). Accordingly, the Hardgrove grindabiUty index exhibits maximum values in this area. 

The drop shatter test indicates the resistance of a coal or coke to breakage on impact (see D440). A sample is dropped in a standard way a number of times from a specified height. Eor the tumbler test or abrasion index (ASTM D441), the coal or coke is rotated in a dmm to determine the resistance to breakage by abrasion (18). 

T and are the glass-transition temperatures in K of the homopolymers and are the weight fractions of the comonomers (49). Because the glass-transition temperature is directly related to many other material properties, changes in T by copolymerization cause changes in other properties too. Polymer properties that depend on the glass-transition temperature include physical state, rate of thermal expansion, thermal properties, torsional modulus, refractive index, dissipation factor, brittle impact resistance, flow and heat distortion properties, and minimum film-forming temperature of polymer latex... 

Gideon, D.N. Belton, W.L., and Stein, R.A., Hypervelocity-Impact Data Index Part I—Bibliography, Battelle Memorial Institute Report No. BAT-197-21-2, Columbus, OH, 60 pp., March 1964. 

Table 9.1 Some collected values for Relative Temperature Index (RTI) (Unless otherwise stated, data are for mechanical without impact and for unreinforced grades)...

Figure II.4. Variation of impact strength with melt flow index (lOkg at I90°C) and isotactic index.

NB The data compares a syndiotactic material with a melt index of 30 and an isotaclic material with an index of 0.3. This should however not invalidate the large differences seen in such properties as modulus, impact strength and opacity.)... 

The gel content (toluene insoluble per cent) of the rubber and the swelling index of the gel (the ratio of the volume of a swollen gel to its unswollen volume). The former is a measure of the amount of cross-linked material and the second a measure of the intensity of cross-linking. It has been found that a sample of medium gel content (5-20%) and a medium swelling index (10-20) gives the best impact strength in the blend. 

As mentioned earlier, unmodified polystyrene first found application where rigidity and low cost were important prerequisites. Other useful properties were the transparency and high refractive index, freedom from taste, odour and toxicity, good electrical insulation characteristics, low water absorption and comparatively easy processability. Carefully designed and well-made articles from polystyrene were often found to be perfectly suitable for the end-use intended. On the other hand the extensive use of the polymers in badly designed and badly made products which broke only too easily caused a reaction away from the homopolymer. This resulted, first of all, in the development of the high-impact polystyrene and today this is more important than the unmodified polymer (60% of Western European market). 

In the absence of fire retardants the material has a limiting oxygen index of 27.5 and may bum slowly. Only some grades will achieve a UL 94 V-1 rating. The Underwriters Laboratories continuous use temperature index is also somewhat low and similar to the polyarylates with ratings of 135-140°C (electrical) and 105°C (mechanical with impact). Initial marketing has emphasised comparisons with the aliphatic nylons for the reasons given in the previous... 

A high UL Temperature Index of 170°C (for mechanical with impact). 

---