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A general model for pressure drop calculations in siphons and riser tubes has been developed. The model takes into account different physical flow phenomena such as inlet pressure drop and pressure drop in the tube. For each phenomenon, we applied theory and established correlations to calculate the separate accelerational, frictional, gravitational, and centrifugal pressure drops. Model results a
This chapter describes the utilization of recent extraction techniques such as supercritical fluid extraction, pressurized liquid extraction and microwave-assisted extraction for the determination of persistent organic pollutants in food and feed samples. These techniques have been developed because the extraction step can severely limit the entire analytical procedure. Several food crises, for ex
After the initial reports of free-floating cultures of neural stem cells termed neurospheres (1,2), a wide array of studies using this promising culture system emerged. In theory, this was a near-perfect system for large-scale production of neural cells for use in cell replacement therapies and to assay for and characterize neural stem cells. More than a decade later, after rigorous scrutiny and a
Fifty years after the foundation of the Combustion Institute and almost 150 years after Michael Faraday's famous lectures on the combustion of a candle, combustion diagnostics have come a long way from visual inspection of a flame to detailed analysis of a combustion process with a multitude of sophisticated techniques, often using lasers. The extended knowledge on combustion phenomena gained by a
[1] Vigorous debate still surrounds the cloud electrification process and unexplained regional variations in lightning activity. Here, we show that climatological maxima in lightning activity are associated with small effective diameter D-e of ice crystals near cumulonimbus cloud tops. This relationship, unlike lightning's more well-known relationship with cloud top height, is consistent over land
The lanthanide elements (Z=57?71) are characterized by the filling of the 4f electronic subshell, which lies close in energy to the 5d and 6s subshells. As a result, the lanthanide spectra can be quite complicated in terms of the number of optical spectral lines, and in some cases their hyperfine structure and isotopic shifts are extremely large. These characteristics have great implications for a
The hygroscopic growth and activation of two HULIS (HUmic LIke Substance) and one Aerosol-Water-Extract sample, prepared from urban-type aerosol, were investigated. All samples were extracted from filters, redissolved in water and atomized for the investigations presented here. The hygroscopic growth measurements were done using LACIS (Leipzig Aerosol Cloud Interaction Simulator) together with a H
The recent development of rapid single sand-sized grain analyses in luminescence dating has necessitated the accurate interpretation of D-e distributions to recover a representative D-e acquired since the last bleaching event. Beta heterogeneity may adversely affect the variance and symmetry of D-e distributions and it is important to characterise this effect, both to ensure that dose distribution
This paper reviews Olof Thorin's contributions to mathematical analysis, actuarial mathematics, and probability theory, though in reversed order. In probability theory he is known for his path-breaking work on infinite divisibility. In actuarial mathematics he contributed significantly to the ruin problem. However, his international fame very much relies on his work in mathematical analysis and hi
Throughout the Cold War Sweden pursued a declared policy of nonalignment. Sweden nevertheless established security links with a number of Western powers, first of all Britain and the US. The most extensive links were developed in two areas - military technology and intelligence. Intelligence liaison was of crucial importance for the security of non-aligned Sweden, but also significant for the majo
The potential of measuring temperature and multiple species concentrations (N-2, O-2, CO) by use of combined vibrational coherent anti-Stokes Raman spectroscopy (CARS) and pure rotational CARS has been investigated. This was achieved with only one Nd:YAG laser and one dye laser together with a single spectrograph and CCD camera. From measurements in premixed sooting C2H4-air flames it was possible
LiBH4 is one of the promising candidates for hydrogen storage materials because of its high gravimetric and volumetric hydrogen capacity. However, its high dehydrogenation temperature and limited reversibility has been a hurdle for its use in real applications. In an effort to overcome this barrier and to adjust the thermal stability, we make a composite system LiBH4-Ca(BH4)(2). In order to fully
Event-related potentials (ERPs) were recorded from 13 scalp sites during the performance of an associative recall task. At study, subjects were presented with a series of word pairs and were required to incorporate the two members of each pair into a sentence. At test, the first members of each pair were presented intermixed with an equal number of unstudied items. Subjects were required to discri
This paper re-examines the validity of the monetary exchange rate model during the post-Bretton Woods era for 18 OECD countries. Our analysis simultaneously considers the presence of both cross-sectional dependence and multiple structural breaks, which have not received much attention in previous studies of the monetary model. The empirical results indicate that the monetary model emerges only whe
Purpose The aim of this study was to evaluate the feasibility of using 1-[C-11]-acetate positron emission tomography (ACE-PET) to detect and delineate the gross tumour volume of head and neck cancer before radiotherapy, and to compare the results with those obtained using F-18-fluoro-2-deoxy-D-glucose (FDG) PET. Methods Ten patients with histologically verified squamous cell carcinoma were investi
The new prominence given to science for economic growth and industry comes with an increased policy focus on the promotion of commodification and commercialization of academic science. This paper posits that this increased interest in commodification is a new steering mechanism for governing science. This is achieved by first outlining what is meant by the commodification of scientific knowledge t
1 In an asexually reproducing plant (Potamogeton pectinatus L.) the competitive advantage of a larger propagule over a smaller one was determined by a single parameter (alpha, the competitive asymmetry coefficient), independent of sowing density or average propagule size. Competitive advantage was determined by the relative size difference between propagules instead of their absolute difference. 2
The polygyny threshold model was introduced in the 1960s in order to explain why females in some species choose to mate vith already mated males. Since then, a number of complementary or alternative hypotheses have been suggested. By using a hierarchical testing approach Searcy and Yasukawa (1989) organised the models that proposed to explain the maintenance of territorial polygyny. Here, I point
