Scale natural

B. Bhushan, J. N. Israelachvili, U. Landman. Nanotribology friction, wear and lubrication at the atomic scale. Nature (London) 374 607-616, 1995. 

Depending upon the corrosive or scaling nature of the liquid in the pipe, it may be necessary to take this condi-... 

When an iron is exposed to an oxidising atmosphere, it develops a scale which consists of a series of layers of oxides of varying composition. The thickness of the scale naturally depends on the temperature and the duration of oxidation (/). The scale does not, however, thicken at a uniform rate with time since its very presence reduces the accessibility of the metal surface to the oxidising gases. Ideally, the thickness of the scale should increase as /t, but in practice cracks develop in the scale, and these allow the gases to reach the metal surface somewhat more readily than is postulated by this relationship. Cracking will always tend to occur as the film... 

In 1929 Pfeil" published a most interesting account of the way layered structures form and the manner in which they influence oxidation rates. From detailed studies of the growth and composition of scales he was able to show clearly how the formation of barrier layers reduced scale formation by hindering outward diffusion of iron through the scale. Naturally, this work had to be largely based on the study of scales of sufficient thickness so that the mechanism of the early stages of oxidation could not be studied in this way. Pfeil analysed the outer, middle and inner layers of scales formed... 

As a practice-based subject, the formation and development of tribology have always been associated with the requirement from society and technology development. Tribology experienced several different stages in its history. Its developing process indicates an obvious trend of integration and combination of multi-scientific subjects in a multi-scale nature from macroscopic dimension to nanometre. 

Cowley, L. and Prichard, M. 1990. Large-Scale Natural Gas and LPC jet Fires and Thermal Impact on Structures. CASTECH 90 Conference. Amsterdam. 

Table 2.1 gives an estimate for global-scale natural and anthropogenic emissions of NOx as well as of CO, CH4, and VOC (Muller, 1992). It is seen that biomass burning and biogenic emissions of NO are comparable and together equal to about half of the anthropogenic emissions. 

In an aftermath of large scale natural or man-made disasters there is likely to be lack of donor sites for SSG harvest to treat extensive bums. Use of isolated keratinocytes which can be actively propagated in vitro [24] and applied in vivo along with dermal substitutes may potentially solve the problem of epithelial deficiency and scarring complications, thus reducing the rates of morbidity and mortality in bums critical care. 

Aunan, B. Thermodynamic analysis of small and medium scale natural gas liquefaction cycles . Public lecture for the degree of doctor ingenior, The Norwegian University for Science and Technology, 1999... 

Wurm, J. Kountz, K.K. Liss, W.E. Small-Scale Natural Gas Liquefier Development , HR Cryogenics 2002, Prague, April 23-26 2002... 

Combining with its small size 3S installation can be used for cooling purposes in LNG technological schemes and has at least the perspective for the problem of small scale natural gas separation and liquefaction. 

Rabi I loud, T. (2003) Membrane proteins ride shotgun - a new mass spectrometry-based approach identifies and characterizes membrane proteins on a large scale. Nature Biotechnology 21, 508-510. 

Secondly, the description of the general procedures given below, as distinct from the specific experimental procedures of the preparations described in earlier chapters, provides an excellent opportunity for the student to explore on the small scale the optimum reaction conditions, the chromatographic monitoring of the reaction, the methods of isolation and purification procedures (solvent extraction, recrystallisation, etc.) for the successful completion of the preparation. The small-scale nature of the experiments is of particular importance in providing experience of those techniques of reaction work-up in which mechanical loss is frequently the reason for failure. Such experience is vital to the synthetic chemist since many of the new chemo-, regio- and stereo-specific reagents are expensive and used in small-scale reactions. 

Ecological/planet Sensitivity to world-scale nature and ecology... 

Climate changes manifest themselves both on global and regional scales. Natural catastrophes are one manifestation of these changes. Their intensity and number increased year on year. A serious increase in the number of great natural catastrophes was observed between 1960 and 2005. The frequency of these events more than doubled during this period. Subsequent years were characterized by various... 

Coal via reforming Small-scale natural gas Electrolysis using nuclear electricity Electrolysis using photovoltaic electricity Electrolysis using wind electricity Wood reforming... 

Populations and communities integrate the effects of environmental conditions over different temporal and spatial scales. Natural communities are characterized as being spatially heterogeneous and temporally dynamic systems (Connell and Sousa 1983 Sousa 1984), and populations may show a high degree of stochastic... 

The development of chemical industry has provided us with the means to produce, on an ecologically significant scale, chemicals that interfere with the natural cycles of synthesis and breakdown either because they accelerate or slow down large-scale natural processes (e.g., the fluoro chloro hydrocarbons which accelerate the breakdown of ozone by sunlight) or, more commonly, because they resist breakdown themselves (e.g., certain synthetic polymers). This has become a matter of grave and widespread concern and has resulted in regulations and voluntary measures to restrict or prohibit the manufacture and use of materials that interfere with the natural cycles. This concern is particularly acute in those cases where this interference has direct or indirect adverse effects upon human health (as in the case of the fluoro chloro hydrocarbons), but it exists also where massive accumulation occurs without known health hazards (as in the case of the too-stable synthetic polymers). 

On a global scale, natural emissions of reduced sulfur compounds account for about 50% of the total sulfur flux into the atmosphere (1-3). Hence, it is important to understand the natural sulfur cycle in order to establish a "base line" for assessing the significance of anthropogenic perturbations (primarily SO2 emissions). Dimethylsul-fide (DMS) is the predominant reduced sulfur compound entering the atmosphere from the oceans (4-9), and DMS oxidation represents a major global source of S(VI). The atmospheric oxidation of DMS can be initiated by reaction with either OH or NO3. In marine environments, however, NO3 levels are typically very low and DMS is destroyed primarily by OH ... 

---