Rational descriptive classification of duricrusts

The term duricrust appears to be extending itself to include calcareous, gypseous, and saline crusts, in addition to crusts composed dominantly of silica and/or of sesquioxides of iron and aluminium, with or without significant contents of dioxides of manganese or titanium. This latter group can be distinguished as duricrusts proper. Its nomenclature is highly confused, and its classification, in writings in the English language, defective. The relevant problems can be resolved, at least in considerable part, by the introduction, adaptation, and extension of modern terms current in tropical pedology, to give a descriptive classification free of genetic implications. When content of SiO₂, Al₂O₃, and Fe₂O₃ is used as a primary basis for the classification of duricrusts proper, plots on a ternary diagram justify the recognition of seven named types in the fersiallitic range

Asymmetric Labour Markets in a Converging Europe: Do differences matter? ENEPRI Working Paper No. 2, January 2001

Asymmetric economic structures across Europe may result in common shocks having asymmetric effects. In this paper we investigate whether the differences in the structure and dynamics that we observe in the European economies matter for policy design. In particular it is widely believed that labour market responses are different, with the structure of labour demand and the nature of the bargain over wages differing between countries. In addition the European economies move at different speeds in response to common shocks. In this paper we construct three different models of Europe, one where the labour market relationships are separately estimated and assumed to be different, one where the most statistically acceptable commonalties are imposed and one where common labour market relationships are imposed across all member countries. We use panel estimation techniques to test for the imposition of commonalties among countries. We find that it is possible to divide Europe into sub-groups, but it is not possible to have one model of European labour markets. We use stochastic simulation techniques on these different models of Europe and find that the preferred rule for the ECB is a combined nominal aggregate and inflation-targeting rule. We find that while this rule is dominant in all our models, the more inertia that is introduced into the labour markets, the more a nominal aggregate-targeting rule alone may be preferred. However, we conclude, that differences in the labour market transmission mechanisms across the European countries appear to have little influence on the setting of monetary policy for the ECB, although this depends on the relative importance of the different components in the welfare loss function

Competition of mixing and segregation in rotating cylinders

Using discrete element methods, we study numerically the dynamics of the size segregation process of binary particle mixtures in three-dimensional rotating drums, operated in the continuous flow regime. Particle rotations are included and we focus on different volume filling fractions of the drum to study the interplay between the competing phenomena of mixing and segregation. It is found that segregation is best for a more than half-filled drum due to the non-zero width of the fluidized layer. For different particle size ratios, it is found that radial segregation occurs for any arbitrary small particle size difference and the final amount of segregation shows a linear dependence on the size ratio of the two particle species. To quantify the interplay between segregation and mixing, we investigate the dynamics of the center of mass positions for each particle component. Starting with initially separated particle groups we find that no mixing of the component is necessary in order to obtain a radially segregated core.Comment: 9 pages, 12 figures (EPIC/EEPIC & EPS, macros included), submitted to Physics of Fluid

Do urban African dwellers pay a premium for food quality and, if so, how much? An investigation of the Malian fonio grain market

Very little data is available concerning the valuation of quality on existing food markets in Sub-Saharan Africa. Using data collected from a survey of fonio (a cereal) retail markets conducted in Bamako, Mali, Africa and a hedonic price Partial Least Square regression method, this study shows that most quality attributes declared as important by consumers have a specific hedonic price that is different from zero. This is interpreted as a result of the efficient performance of so-called traditional informal markets. Among the valued attributes, some are physical (colour, degree of milling) and thus relatively easy to assess, while the assessment of others (category or country of origin) are more complicated for both parties to the transaction. These attributes, however, also have specific hedonic prices. Informal norms and a certain amount of trust are thus present in these markets and should not be underestimated. The inclusion of buyer characteristics in the model is justified by the differences in bargaining power, which are essentially linked with different levels of experience buying or using the product. We showed that women were getting better prices for the same product quality. The premiums paid for quality varied from 1 to 14% of the price. These estimates have confirmed the other few estimates done in African food markets.fonio, cereal, quality, hedonic prices, PLS method, empirical investigation

Energy markets and the macroeconomy

The article looks at the energy markets from a macroeconomic perspective. It first describes the main trends in the production and consumption of energy. Belgium is characterised by a high degree of energy dependency, since it no longer has any fossil fuel resources and renewable energy is not yet well developed in the country. Moreover, its economy has a high energy intensity, due to specialisation in energy-intensive sectors and high consumption of energy products by Belgian households. The operation of the energy markets and the implications for the pricing of energy products is examined in a second part. The pass-through of fluctuations in the price of crude oil onto consumer prices of petrol, diesel and heating oil is both fast and full, in Belgium as well as in the neighbouring countries. However, because of the low level of excise duty on diesel and particularly on heating oil, consumer prices charged for these energy products in Belgium are more sensitive to fluctuations in the crude oil price. Also, the Belgian consumer price of gas and electricity reacts much faster than in neighbouring countries to fluctuations in prices on the international markets, since in other euro area countries, prices are adjusted less frequently than in Belgium and in some cases they are still subject to some form of regulation. More generally, despite liberalisation, the effective degree of competition on the gas and electricity markets is still very low, both in Belgium and in the other euro area countries. Finally, the impact of fluctuations in crude oil prices on inflation and economic activity is discussed. In addition to its high energy intensity and strong reactions of its energy consumer prices to oil price fluctuations, the Belgian economy’s sensitivity to oil shocks is heightened by the indexation mechanism it applies, even though the use of the health index partly neutralises the initial shock. However, that additional negative impact can be curbed by constant monitoring of Belgian competitiveness, as prescribed by a 1996 law on the promotion of employment and the safeguarding of competitiveness.energy markets, oil, inflation, pass-through, Belgium