Effects of Alkali on Water Soluble Hexavalent Chromium in Ordinary Portland Cement.

Due to the toxicity and mobility of chromium, the disposal of chromium-containing waste is a pressing issue. Co-processing of chromium-containing waste in a cement kiln is currently one of the most effective methods. However, the presence of water-soluble hexavalent chromium (Cr(VI)) in cement limits the use of this method. In this study, Na2CO3 was used to simulate alkali in industrial raw materials to investigate the pattern of influence of alkali content on water-soluble hexavalent chromium. The mechanisms associated with the oxidation and dissolution of chromium were investigated using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma emission spectrometry (ICP-OES). The proportion of Cr(VI) in the clinker detected by XPS increased rapidly with increasing alkali content. In the cement slurry system, alkali promotes more hexavalent chromium leaching by influencing pH and other ion concentrations (Ca2+, SO42-). Therefore, the addition of alkali to either the raw meal or to the cement slurry system will favour an increase in the water-soluble Cr(VI) content. This study may provide theoretical guidance for the preparation and use of clinkers containing chromium.

cis-4-(Tosyl-oxymeth-yl)cyclo-hexa-ne-carboxylic acid.

The title compound, C(15)H(20)O(5)S, is an inter-mediate in the synthesis of novel amino-carboxylic acid derivatives. The cyclo-hexane ring exhibits a chair conformation. In the crystal structure, adjacent mol-ecules form dimers via O-H⋯O hydrogen bonds.

[Preparation of contraceptive pill microcapsule and its anti-fertility effect].

The main component of this pill is 2-Octadecanoic acid-4-Palmitic acid-2, 4-Pentanediyl ester separated from chloroform extract of neem oil. The microcapsules coated by the re-curdle method were fabricated with an average particle size of 100-180 microm. The morphological characteristics, incorporation efficiency, carrier reclamation efficiency of the microcapsule were investigated. Kunming mice were used in the experiment, and the anti-fertility effect of the microcapsule on the histology and apoptosis was studied by light and electron microscopy and the flow cytometry. The data obtained clearly indicated that the microcapsule could lead to the payload of medicine, the incorporation efficiency being 90%. After the microcapsules were given to the male mice orally, its anti-fertility effect came into being and could keep the mice in a state of reversible infertility for a long time. The results of histological study and flow cytometry indicate that the mechanism of its anti-fertility effect involves mainly the inhibition of sperm motility and the arrest of spermatogenic process.