Investigations of the 500mb level in relation to the general circulation

Summary The redistribution of kinetic energy in the 500mbar level is studied for 1966 as well as for 1967. The total kinetic energy is split up in three parts: a) the energy due to the mean flow, b) the energy due to eddies with a period of time longer than a month and c) the energy due to eddies with a period of time less than a month but longer than one day.The transport of these energies takes place in formally three different ways, namely by the mean flow, by longperiod and shortperiod eddies (or monthly and daily eddies).Both the transports in zonal and meridional direction are studied. As will be shown in section 2, this yields 16 transportterms. It turns out that for the 500mbar level in the region from 100°W to 30°E and from 30°N to 65°N and based on geostrophic approximated winds: a) the longperiod eddies are important, b) the role of the longperiod eddies as well as the role of the shortperiod eddies decreases with increasing latitude and c) the zonal transports and the divergence of those transports are mostly larger than the meridional transports, and the divergence of the meridional transports.

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Untersuchungen der 500 mbar-Fläche in bezug auf die allgemeine Zirkulation,

Zusammenfassung Die Verteilung der kinetischen Energie im 500mb-Niveau wird für die Jahre 1966 und 1967 untersucht. Die gesamte kinetische Energie wird dabei in drei Teile zergliedert: a) die kinetische Energie der mittleren Strömung, b) die Energie aus länger als einen Monat andauernden Wirbeln und c) die Energie aus kürzer als einen Monat, aber länger als einen Tag andauernden Wirbelelementen.Der Transport dieser Energien erfolgt formal auf drei verschiedenen Wegen, nämlich durch die mittlere Strömung, durch lang- und kurzperiodige Wirbelelemente (Turbulenzelemente von Monatsdauer bzw. von Tagesdauer). Es werden die Transporte in zonaler und in meridionaler Richtung untersucht; daraus ergeben sich 16 Transportterme. Für die Region von 100°W bis 30°E und 30°N bis 65°N erweist sich unter Zugrundelegung geostrophisch approximierter Winde, a) daß langperiodige Wirbel von Bedeutung sind, b) daß die Bedeutung langperiodiger wie auch kurzperiodiger Wirbelelemente mit zunehmender geographischer Breite abnimmt und c) daß die zonalen Transporte und ihre Divergenz meistens größer sind als die meridionalen Transporte und die Divergenz meridionaler Transporte.

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With 25 Figures     

Scandium in rocks,minerals and sediments and its relations to iron and aluminium

Scandium, aluminium and iron contents of a considerable number of rocks, minerals and sediments for various origin are given. They have been obtained by instrumental neutron activation analysis.The concentrations of these elements in rocks and minerals are very variable. However the Fe/Sc and Al/Sc ratios for the finer particles of sediments from different origins are fairly constant. At a spec. surf. of 100 m²/g is found 0.2 to 0.3 × 10⁴ for Fe/Sc and 0.60 to 0.95 × 10⁴ for Al/Sc (mol).In the coarser sediments there is a considerable influence of particle size. Consequently when Sc-contents of sediments are compared for classification purposes, their spec. surf. or granulometric composition should be determined as well.     

O-H stretching vibrations in kaolinite,and related minerals

The grades of ordering as represented by I.R. and X-ray spectra for platy kaolinite, fire clay mineral, ball clay, dickite, nacrite and tubular dehydrated halloysite samples of various origin, are related.Well ordered kaolinite, has four bands 3,693, 3,668, 3,652 and 3,620 cm^–1. In less ordered kaolinite, fire clay mineral and ball clay these bands have shifted a little or of the middle two, which are the weakest, only one band may be left (between brackets): less ordered kaolinite: 3,695, 3,667, 3,652 (3,653) and 3,620 cm^–1; fire clay mineral 3,696, 3,668, 3,653 (3,653) and 3,621 cm^–1; ball clay 3,697, 3,652 and 3,621 cm^–1.Dehydrated halloysite has 3,693–3,698, 3,668, 3,650–3,654 and 3,620–3,626 cm^–1 bands. In the most disordered dehydrated halloysite samples (Martinsberg and Baia Mare) only two bands are left at 3,696 and 3,624 cm^–1.Dickite has four bands: 3,708, 3,656, 3,627 and 3,622 cm^–1. For the lesser ordered Mexico sample it is 3,701, 3,652, 3,627 and 3,621 cm^–1. Nacrite also has four bands i.e.: 3,700, 3,650, 3,627 and 3,620 cm^–1.There is, apart from orientation effects, a wide variation in the absolute and especially in the relative intensities of the I.R. bands and X-ray reflections for each of the mineral groups investigated here, but of various origin. The need of a nomenclature adapted to the level of our knowledge about this matter to day and comprising all these variations included those in morphology is emphasized.Quantitative analyses, the adjective meant in the sense of an accuracy of minimal 5%, constitute a difficult problem which is perhaps even wholly impossible to solve with the conventional methods of today.     

The efficiency of the conversion of solar energy into wind energy by means of Hadley cells

Summary In the present paper, we apply endoreversible thermodynamics in order to calculate the upper bound for the fraction of solar energy absorbed by the Earth, that can be converted into the mechanical energy present in the atmosphere. We assume the presence of six Hadley cells in the Earth's wind system and find an upper limit of 1.17%. For Mars we assume a single Hadley cell and find an upper limit of 0.87%.With 10 Figures     

25 years of mineral exploration and discovery in Indonesia

This paper traces the history of mineral exploration in Indonesia between 1967 and 1992, and discusses various technical aspects, such as area selection, exploration and discovery methods, and significant geologic features of the more important new discoveries.Exploration activity over the past 25 years can be divided into four main phases. Phase 1 (1967–1976) mostly involved investigations of mineral prospects and districts previously identified by the Dutch. These investigations resulted in many discoveries, including: a major copper-gold district (skarn-porphyry copper) in Irian Jaya, where exploration is still in progress (resources identified to date: 28 Mt Cu and 2,700 t Au); large nickel resources in Eastern Indonesia (13 Mt Ni); significant onshore and offshore tin resources in the Sumateran tin belt (0.13 Mt Sn); and large but low grade bauxite deposits in West Kalimantan (300 Mt Al₂O₃). Of the eight Contracts of Work signed between 1967 and 1972, six reached the mining stage. Phase 2 (1970–1975) consisted of an extensive porphyry copper search in the Sunda arc, the western arc of Sulawesi and the central belt of Irian Jaya. Best results were obtained from northern Sulawesi, where follow-up between 1976 and 1982 identified three potentially economic copper-gold deposits (1.7 Mt Cu and 140 t Au) and one subeconomic molybdenum porphyry system (0.8 Mt Mo). During Phase 3 (1981–1988) extensive coal exploration in South and East Kalimantan delineated over 5,000 Mt of coal of varying rank and quality, including 1,500 Mt as measured reserves in 17 deposits, eight of which have been developed to date. Phase 4 (1984–1990) involved a major gold rush, focused primarily on the Cenozoic magmatic belts of Kalimantan, Sulawesi, Moluccas and the Sunda arc. Over 80 primary and alluvial gold prospects were drill tested. Five of these were brought into production (two alluvial deposits, two new hard rock discoveries and one Dutch mine), containing approximately 135 tonnes of mineable gold, and several other projects are under development or undergoing feasibility studies. Total geological resources identified to date are estimated to contain about 700 tonnes of gold. Exploration during phase 4 also resulted in several gold-rich porphyry copper discoveries, including a major deposit in Sumbawa (2.7 Mt Cu and 250 t Au). Intermittent exploration for uranium, diamonds and lead/zinc since 1969 has been largely unsuccessful.Exploration is now passing to the next phase, which is likely to be multi-commodity in nature with a strong focus on gold, copper and coal. A number of deposits outlined during earlier phases will be developed.The unprecedented high level of mineral exploration activity over the past 25 years can be attributed to Indonesia's mineral prospectivity and favourable investment climate. Given a continued competitive commercial environment and sustained commodity prices, the next 25 years should see further strong development of the country's mineral resources.     

Groundwater contaminant transport including adsorption and first order decay

This study deals with the transport of a contaminant in groundwater. The contaminant is subject to first order decay or linear adsorption. Its displacement can be modeled by a random walk process in which particles are killed at exponentially distributed times. Dirichlet problems are derived for the rate and mean time at which contaminated particles reach a particular part of the boundary of a certain domain. These Dirichlet problems are solved asymptotically for two types of 2D-flow patterns: flow parallel to the boundary of a domain and arbitrary flow towards a well in an aquifer.