Suchergebnisse

SummaryThis paper examines data on fertility levels in 33 Moslem countries between 1960 and 1980. Fertility measures include crude birth rate, total fertility rate and age-specific birth rate, and the percentage change in them between 1960 and 1980.The analysis focuses on: (1) the current status of Moslem fertility in comparison to non-Moslem countries in the same region; (2) the emerging fertility differentials among Moslem countries; (3) how much of the recent fertility declines in some Moslem countries is associated with modernization variables and with family planning efforts.The results indicate that: (1) Moslem fertility remains universally high and is generally higher than in non-Moslem countries in the same region; (2) very few Moslem countries have succeeded in bringing down their level of fertility to justify a search for the predictors of Moslem fertility levels; (3) in spite of a sufficient range of variations in the economic and social correlates of fertility, the corresponding fertility variables in these countries do not suggest that the reproductive behaviour of Moslem women has reacted to such variations; (4) efforts directed towards stronger family planning programmes are clearly related to fertility decline.

Grundzüge und -probleme der Entwicklung in den arabischen Erdölländern am Golf mit besonderer Berücksichtigung der kuwaitischen Situation: Arbeitskräfteimport, Beziehungen zu den Industrieländern, Rolle des Konsums, Sparen und Investitionen, Wohlstand und soziale Sicherung; die OPEC-Länder als Repräsentanten eines neuen Entwicklungsmodells, dessen Haupt-Inputfaktor die unbegrenzte Verfügbarkeit von Kapital ist. (DÜI-Hns)

Abstract
Background
Carbon dots (CDs) are of particular interest in numerous applications. However, their efficiency for heavy metal removal from wastewater was not yet reported. Herein, we rationally synthesized CDs from petroleum coke waste via hydrothermal treatment in the presence of ammonia.

Results
This drove the formation of outstanding photoluminescent, water-soluble, biocompatible, and high yield of monodispersed sub-5 nm CDs. The CDs are co-doped with high 10% of N and 0.2% of S. The as-prepared CDs possess unprecedented photoluminescent properties over broad pH range making these dots unique efficient pH sensor.

Conclusions
Chitosan (CH)–CDs hybrid hydrogel nanocomposite film was further prepared as a platform membrane for the removal Cd2+ metal from wastewater. The as-prepared CH–CDs membranes show relatively good mechanical properties, based on stress resistance and flexibility to facilitate handling. The equilibrium state was reached within 5 min. Intriguingly, the UV-light illuminations enhanced the Cd2+ removal efficiency of the photoluminescent CDs substantially by four times faster under. It was found that adsorption followed pseudo-second-order kinetic and Langmuir isotherm models. The maximum adsorption capacity at 25 °C was found to be 112.4 mg g−1 at pH 8. This work paves the way to new applications of CDs in water treatment.

AbstractBackgroundFatty alcohol polyoxyethylene ether-7 (AEO-7), a non-ionic surfactant, has recently been receiving extensive attention from the ocean pipeline industry for its ability to inhibit corrosion. However, the present lack of information concerning the potential environmental toxicity of AEO-7, especially towards aquatic organisms, is a major impediment to its wider application. Here, we assess potential adverse effects of AEO-7 on zebrafish embryos employing a variety of assays, including (i) a mortality/survival assay which allowed the median lethal concentration (LC50) to be calculated; (ii) a teratogenicity assay on the basis of which the no observed effect concentration (NOEC) was determined; and (iii) specific assays of cardiotoxicity, neurotoxicity (based on locomotion), hematopoietic toxicity (the level of hemoglobin as revealed byo-dianisidine staining) and hepatotoxicity (liver steatosis and yolk retention examined by staining with Oil Red O).ResultsAEO-7 caused mortality with a calculated LC50of 15.35 μg/L, which, according to the U.S. Fish and Wildlife Service (USFWS) Acute Toxicity Rating scale, should be considered "super toxic". Although at its NOEC (0.8 μg/L), there were no signs of significant teratogenicity, cardiotoxicity, or hemopoiesis toxicity, 3.2 µg/L AEO-7 exerted dramatic detrimental effects on organ development.ConclusionOn the basis of these findings, we recommend that the industrial usage and environmental impact of AEO-7 be re-evaluated and strictly monitored by environmental and public health organizations.