Scintillation prediction models compared to measurements on a timebase of several days

The prediction models for scintillation variance of ITU-R and Karasawa et al. (1988) are compared to measurements on a time base which is much shorter than originally considered for these models. It is shown that even after averaging over just three days, a good correlation with the measured variance is found. Both models predict higher scintillation variance than is measured at 19.8 GHz on a 12.7° elevation path in Kirkkonummi, Finland     

Some elements in domestic and imported fresh fruits marketed in the Netherlands

Summary Sodium, potassium, arsenic, selenium and tin have been determined in 38 different types of domestic and imported fresh fruits. All samples (n=242) were analysed for Na und K whereas a limited number of samples (n=85) of each fruit type was selected for the determination of As, Se and Sn. The median contents, in mass fractions of the edible portion, found for fresh fruits are: Na<0.001%; K 0.17%; As 4 g/kg; Se 2 g/kg and Sn< 0.05 mg/kg. The corresponding 90th percentile values are: Na 0,002%, K 0.34%; As 12 g/kg; Se 10 g/kg and Sn 0.10 mg/kg. Results for selenium reported here differ substantially from those given for a number of fresh fruits in the German Food Composition Tables 1986/1987. The average consumption of 129 g fresh fruit by Dutch citizens in the age category of 22–75 years contributes, in general, marginally to the total daily dietary intake of sodium, arsenic, selenium and tin. Fresh fruit can contribute substantially, up to 23%, to the average oral daily intake of potassium.

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Einige Mineralstoffe im einheimischen und importierten Frischobst vom niederländischen Markt

Zusammenfassung Natrium, Kalium, Arsen, Selen und Zinn wurden in 38 verschiedenen Sorten von in- und ausländischem Frischobst bestimmt. Alle Proben (n=242) wurden auf Na und K untersucht; während nur eine beschränkte Zahl von Proben (n=85) für die Bestimmung von As, Se und Sn ausgewählt wurde. Die Medianwerte, in Massenanteilen der eßbaren Portionen, betrugen für frisches Obst: Na<0,001%; K 0,17% As 4 g/kg; Se 2 g/kg und Sn<0,05 mg/kg. Die dazugehörigen Werte für den 90 Perzentil sind: Na 0,002%; K 0,34%; As 12 g/kg; Se 10 g/kg und Sn 0,10 mg/kg. Für einige Obstsorten wurden Selenwerte erhalten, die erheblich von denen der Deutschen Nährwert-Tabellen 1986/1987 abweichen. Frischobst, dessen Verzehr für Einwohner der Niederlande in der Altersklasse von 22–75 Jahre im Schnitt 129 g/Tag beträgt, liefert einen vernachlässigbaren Beitrag zur täglichen Einnahme von Natrium, Arsen, Selen und Zinn; für Kalium hingegen kann dieser Beitrag, mit bis zu 23%, erheblich sein.

     

Chosen postures during specific sitting activities

This research study analysed the interaction between people's postures and activities while in semi-public/leisure situations and during transportation (journey by train). In addition, the use of small electronic devices received particular emphasis. Video recordings in German trains and photographs in Dutch semi-public spaces were analysed using a variation of Branton and Grayson's (An evaluation of train seats by observation of sitting behaviour. Ergonomics, 10 (1), (1967), 35-51) postural targeting forms and photos. The analysis suggests a significant relationship between most activities and the position of the head, trunk and arms during transportation situations. The relationship during public situations is less straightforward. Watching, talking/discussing and reading were the most observed activities for the transportation and leisure situations combined. Surprisingly, differences in head, trunk, arm and leg postures were not significant when using small electronic devices. Important issues not considered in this study include the duration of the activities, the gender and age of observed subjects and the influence of the time of day. These are interesting issues to consider and include for future research. STATEMENT OF RELEVANCE: This study shows what activities people choose to carry out and their related postures when not forced to a specific task (e.g. driving). The results of this study can be used for designing comfortable seating in the transportation industry (car passenger, train, bus and aircraft seats) and semi-public/leisure spaces.     

Deterministic extractors for small-space sources

We give polynomial-time, deterministic randomness extractors for sources generated in small space, where we model space s sources on ${\{0,1\}}^n$ as sources generated by width $2^s$ branching programs. Specifically, there is a constant $\eta >0$ such that for any $\zeta >n^{?\eta }$, our algorithm extracts $m=(\delta ?\zeta )n$ bits that are exponentially close to uniform (in variation distance) from space s sources with min-entropy δn, where $s=\Omega ({\zeta }^{3}n)$. Previously, nothing was known for $\delta ?1/2$, even for space 0. Our results are obtained by a reduction to the class of total-entropy independent sources. This model generalizes both the well-studied models of independent sources and symbol-fixing sources. These sources consist of a set of r independent smaller sources over ${\{0,1\}}^{?}$, where the total min-entropy over all the smaller sources is k. We give deterministic extractors for such sources when k is as small as $\mathsf{polylog}(r)$, for small enough ?.     

Parametric toeplitz systems

This paper investigates the properties of the two-variable polynomialu (, z) built on the first column of the adjoint matrix ofI -C, whereC is a given Hermitian Toeplitz matrix. In particular, the stability properties ofu (,z) are discussed and are shown to depend essentially on the location of X with respect to the eigenvalues ofC. The eigenvectors ofC, which have recently found some applications in signal processing and estimation theory, are obtained from the polynomialu(,z) when tends to the eigenvalues ofC. This allows one to derive several results concerning the eigenpolynomials, including those for the case of multiple eigenvalues.     

Correlating the effects of ash elements and their association in the fuel matrix with the ash release during pulverized fuel combustion

During pulverized fuel combustion, inorganic elements such as alkalis, sulfur, chlorine, calcium and magnesium, as well as a range of minor elements are partly released into the gas phase. These gas-borne species can nucleate, coagulate and condense to form either aerosol particles or sticky layers on ash particles, leading to ash deposition and corrosion problems in power utilities. Furthermore, the fine aerosols can lead to harmful gaseous and particulate emissions. It is well documented that the mode of occurrence and the chemical speciation of ash forming elements in the coal/biomass structure are important for the release behavior of mineral components. In the presented work, this is investigated by performing quantitative elemental investigations of ash releases for two different coals (a Polish and a UK coal) and six diverse biomass fuels (Wood bark, Wood chips, Waste wood, Olive residue, Saw dust and Straw). The tests are performed within the Lab-scale Combustion Simulator (LCS) of the Energy Research Centre of the Netherlands (ECN). The operating conditions applied were that of a typical pulverized fuel (PF) fired boiler i.e. atmospheric pressure, high temperatures of 1400-1650 °C, and high heating rate of 10⁵ K/s. Gas phase elemental release of alkalis, sulfur, chlorine, calcium and magnesium has been quantified at relevant high carbon conversion levels. With the performed set of experiments several of the past observations from the literature are reconfirmed. In addition to this, based on the extensive data pool at hand, a simple but reliable (R² > 0.95) set of linear correlations have been proposed to predict the elemental release of potassium, sodium, chlorine and sulfur. It is also concluded that such linear expressions can be particularly effective for the prediction of elemental release from the fuels of similar characteristics, such as woody biomass.     

Maternal and fetal plasma concentrations of endothelin, lipidhydroperoxides, glutathione peroxidase and fibronectin in relation to abnormal umbilical artery velocimetry

The topoisomerase II alpha (topo II alpha) enzyme is the target for several chemotherapeutic agents, including etoposide, teniposide, mitoxantrone, and doxorubicin (topo II poisons). The enzyme also is a marker of cell proliferation. Most cases of Hodgkin's disease (HD) are responsive to combination chemotherapy regimes that include topo II poisons such as doxorubicin. Immunoperoxidase methods for detection of the topo II alpha isoenzyme are now available for use in formalin-fixed, paraffin-embedded tissues, which may provide information about the proliferative capacity and possible sensitivity of tumors to drugs that target topo II. We used a specific antibody to analyze subsets of HD for topo II alpha staining patterns. Formalin-fixed blocks from 49 cases of HD, including 20 nodular sclerosis (NS), 14 mixed-cellularity (MC), and 15 lymphocyte-predominant (LP) subtypes, were analyzed by dual staining for topo II in combination with monoclonal antibodies against Reed-Sternberg (RS) cells consisting of CD15 for the NS and MC subtypes and CD20 for LP lymphocytic and histiocytic (L & H) cells. The number of morphologically appropriate cells coexpressing the RS or L & H marker and topo II alpha was quantitated. Positive nuclear staining for topo II alpha in RS or L & H cells was seen in 100% of cases, irrespective of subtype. Coexpression of CD15 and topo II alpha was seen in 58.4% of the RS cells or mononuclear variants in NSHD cases and 68.4% in MCHD cases. No significant difference in the percentage of neoplastic cells expressing topo II alpha was found between NS and MC subtypes. Cases of LPHD showed coexpression of CD20 and topo II alpha in 84.4% of the L & H cells, a significant increase over the level of tumor cell coexpression seen in NSHD and MCHD (P < .001). Only one case was found to have a low (< 25% of tumor cell coexpression) level of topo II alpha expression. Immunohistochemical detection of a high level of topo II alpha expression in HD, irrespective of subtype, suggests a molecular explanation for the excellent response of most HD to standard combination chemotherapy, which can include topo II poisons. The LP subtype has a higher expression of topo II alpha in the neoplastic cell population than do NS or MC subtypes, perhaps indicating increased sensitivity of these tumors to topo II poisons. It may be possible to identify subsets of HD that are more or less sensitive to conventional chemotherapeutic regimes, which would help in the selection of appropriate treatment.     

Characterization theorems for bounded and positive two-variable functions

The aim of this paper is a two-variable extension of some classical results by Carathéodory and Schur, characterizing the classes of positive and bounded analytic functions. It is shown how these functions can be approximated by a convergent sequence of polynomials of the same class. The particular case where bounded two-variable functions reduce to rational inner functions is described. As an application, the integral representation of positive functions is used to generate the complete family of two-variable reactances of the first degree.