Analysis of investments in technology development and resource conservation

A methodology is presented for the economic analysis of investments in research, technology development and water resources conservation. The role of technology development and resource conservation is directly related to the availability of resources. Mathematically speaking, we are dealing with a problem in which part of the control variables are investments on technologies related to the manufacturing of diverse products. The methodology enables the decision maker to distribute efficiently restricted amounts of capital and resources to the different manufacturing systems so as to achieve the most profitable combination of production levels.Using the so called ‘technology function’, the solution procedure consists of a combination of decomposition and dynamic programming. Two specific technology functions are considered as examples and it is shown how analytical consideration can be incorporated in the solution procedure so as to reduce computational requirements.Possible extensions of the problem are also discussed.     

Climate of the last 53,000 Years in the eastern Mediterranean, based on soil-sequence Stratigraphy in the coastal plain of Israel

In this paper we present a detailed record of proxy-climatic events in the coastal belt of the eastern Mediterranean during the past 53,000 years. A sequence of alternating palaeosols, aeolianites, and dune sands, which have been dated by luminescence and by ¹⁴C, was studied by the magnetic susceptibility, particle-size distribution, clay mineralogy and soil micromorphology. Thirteen proxy-climatic events, demonstrating fluctuations of relatively dry and wet episodes, were recognized. The soil parent materials, as well as the different soil types, were rated in a semi-quantitative “dry” to “wet” scale. The palaeosol sequence is compared to a proxy-climatic record of oxygen and carbon isotopes in speleothems from a karstic cave in central Israel and to a record of lake levels of Lake Lisan and its successor, which is known as the Dead Sea. A genuine red Mediterranean Soil (Rhodoxeralfs), localy designated as “Hamra Soil” developed during the Last Glacial Stage, from 40 to 12.5 thousand calendar years BP. Climatic fluctuations that were recorded in speleothems and in changing lake levels were not preserved in this soil. During the cold and dry Younger Dryas, ca 12.5 to 11.5 calendar ka BP, a thick bed of loess material, deriving from atmospheric dust of the Sahara and Arabian deserts, covered the entire coastal belt. During this phase Lake Lisan was desiccated and turned into the modern, smaller Dead Sea. During the early Holocene, some 10–7.5 calendar ka BP, a second Red Hamra soil developed in warm and wet environments, associated with a relatively high stand of the Dead Sea level. A depletion of δ¹⁸O and a significant enrichment of δ¹³C in the speleothems were recorded during this episode. This event was in phase with the widespread distribution of freshwater lakes in the Sahara Desert and the accumulation of the S1 Sapropel in the eastern Mediterranean. Several small-scale dry and somewhat wet fluctuations of the Late Holocene, from 7.5 calendar ka BP to the present, were recorded in the coastal belt. Changes in human history, as reflected in archaeological records, are associated with proxy-climatic fluctuations. Periods of desertification and deterioration are coupled with dry episodes; periods of relative human prosperity are coupled with wetter episodes.     

Residual displacements and strains due to faulting in real Earth models

Static displacements and strain fields are computed at the free surface of a gravitating radially-heterogeneous earth model. The numerical results indicate that the fields corresponding to a real earth model differ meaningly with comparison to a homogeneous non-gravitating model.The theory is applied to the Alaskan earthquake of March 28, 1964. The strains recorded at Isabella agree with the calculated values; but those at Kippapa and Green Observatory are larger than the theoretical values. In all cases the observed and calculated values are of the same order of magnitude.     

The pathway of trace elements during oil shale combustion—A clue to their availability for leaching processes

A model for the pathway of some trace elements during fluidized-bed combustion of israeli oil shale is suggested, based both on pilot plant and laboratory tests. This model demonstrates the role of carbonate matrix in suppressing the volatilization of trace elements due to fixation of most elements in new-formed silicates. The quality of leachates derived from oil shale combustion wastes can be predicted on the basis of the proposed model.     

The origin of the Dead Sea rift

The Dead Sea rift is considered to be a plate boundary of the transform type. Several key questions regarding its structure and evolution are: Does sea floor spreading activity propagate from the Red Sea into the Dead Sea rift? Did rifting activity start simultaneously along the entire length of the Dead Sea rift, or did it propagate from several centres? Why did the initial propagation of the Red Sea into the Gulf of Suez stop and an opening of the Gulf of Elat start?

Using crustal structure data from north Africa and the eastern Mediterranean and approximating the deformation of the lithosphere by a deformation of a multilayer thin sheet that overlies an inviscid half-space, the regional stress field in this region was calculated. Using this approach it is possible to take into account variations of lithospheric thickness and the transition from a continental to an oceanic crust. By application of a strain-dependent visco-elastic model of a solid with damage it is possible to describe the process of creation and evolution of narrow zones of strain rate localization, corresponding to the high value of the damage parameter i.e. fault zones.

Mathematical simulation of the plate motion and faulting process suggests that the Dead Sea rift was created as a result of a simultaneous propagation of two different transforms. One propagated from the Red Sea through the Gulf of Elat to the north. The other transform started at the collision zone in Turkey and propagated to the south.     

Relativistic heavy cosmic rays

During three balloon flights of a 1 m² sr ionizationchamber erenkov counter detector system, we have measured the atmospheric attenuation, flux, and charge composition of cosmic-ray nuclei with 16Z30 and rigidity greater than 4.5 GV.The attenuation mean-free-path in air of VH (20Z30) nuclei is found to be 19.7±1.6 g cm^–2, a value somewhat greater than the best previous measurement. The attenuation mean-free-path of iron is found to be 15.6±2.2 g cm^–2, consistent with predictions of geometric cross-section formulae.We measure an absolute flux of VH nuclei 10 to 20% higher than earlier experiments at similar geomagnetic cutoff and level of solar activity. The relative abundances of evencharged nuclei are found to be in good agreement with results of other recent high-resolution counter experiments.We calculate that our observed cosmic ray chemical composition implies relative abundances at the cosmic-ray source of Ca/Fe=0.12±0.04 and S/Fe=0.14±0.05. The results are consistent with all other elements of charge between 16 and 26 being absent at the source and being produced by cosmic-ray fragmentation in interstellar hydrogen. The results show the ratios A/Fe and S/Fe to be significantly lower in the cosmic-ray source than in the solar system.     

Soil parent materials and the pottery of Roman Galilee: A comparative study

The paper presents a comparative micromorphological analysis of the range of soil materials used to make the pottery of the hilly Galilee during the Roman period, and the ceramic products made from these materials. The four soil units that served as raw material for most of the pottery made in this period and region are examined along with pottery derived from each of them. For each soil unit, the soil characteristics and processes are described, followed by a presentation of the micromorphological characteristics of the soil material and those of the pottery made from that material. The contribution of the aeolian dust component to the soil materials is discussed as well as the identification of the tempering materials (nonplastics or other soil materials) added to the pottery paste. The study demonstrates the close correlation in microfabric between the pottery and original soil materials, sheds light on the raw material selection and modification practices of the potters of Roman Galilee, and has significant implications for provenance studies, using chemical analysis, on the pottery of this period and region. © 2002 Wiley Periodicals, Inc.     

Sources of Salinity Variation in a Coastal Lagoon in a Karst Landscape

Bahia de la Ascension (BA) is a shallow, mangrove-fringed coastal bay connected to the Caribbean through two inlets, outlined by the Mesoamerican Barrier Reef System. This work represents an initial investigation of the relative contribution of hydrometeorological and hydrodynamic forcing on salinity variation in this lagoon. Our objective is to assess the sensitivity of the salinity in BA to fluctuations in freshwater inflow and coastal oceanography. Two field trips were undertaken during rainy and dry seasons in 2007. Surface salinity was mapped across the system and CTD deployments carried out within BA and in the sea end-member to characterize temperature, conductivity, and water level. Also, cross-sectional CTD profiles were implemented to examine vertical stratification. The water balance indicated that 16 % of rainfall over the drainage basin (DB) becomes groundwater discharge plus surface runoff into BA during dry season, while 68 % of the precipitation input to the DB is supplied through groundwater–surface runoff to the bay during rainfalls. This combined inflow showed larger fluctuations than direct rainfall and, thus, has a greater potential to alter the seasonal salinity variations within BA. The tidal signal is selectively attenuated within BA, as diurnal frequencies are more readily filtered out than semidiurnal frequencies. Mesohaline conditions in the southwest bay are associated with freshwater sources, while saline water masses in the inlet are influenced by prevalent SE winds in the region and tidal phase, establishing a strong horizontal SW-NE estuarine salinity gradient.