On the sedimentary occurrence of chlorophyllone a

The 13(2),17(3)-cyclopheophorbide a enol (CPP) is shown to convert mainly to a approximately 1:1 mixture of (13(2)R/S) chlorophyllones a (Chlone), when chromatographed over silica gel or alumina supports. 15(1)-hydroxychlorophyllonelactone a and some other chlorophyll a related compounds are also tentatively identified as minor transformation products of CPP. This raises the possibility that the chlorophyllones reported in recent sediments may be analytical artifacts from CPP. However, data for the surface sediments from Lake Motte as well as literature data for other contemporary sediments show that, (i) they are not artifacts, (ii) considering that CPP is the intermediate compound in the formation of chlorophyllones from chlorophyll a, the hydroxylation of CPP in the sedimentary environment involves an enzymatic process leading preferentially to 13(2)S chlorophyllone a.     

Maximum ground level concentration for Gaussian plume formula using standard and Briggs methods

This work aims to determine the maximum concentration and downwind distance at the earth's surface in two methods Briggs and standard for two conditions are slightly unstable and neutral by using the Gaussian equation at different effective heights and wind seeped at (8.9, 8.5 and 8 m/s) under lateral and vertical dispersion coefficient measurement.     

Ameliorative potential of manganese nanoparticles with low-level ionizing radiation against experimentally induced hepatocarcinogenesis

Environmental Science and Pollution Research - Nanotechnology is a rich field with infinite possibilities of drug designs for cancer treatment. We aimed to biosynthesize manganese nanoparticles (Mn...     

Effect of Museum Conditions on Historical Dyed Silk Fabric with Madder Dye

Historical textiles suffer from deterioration as a result of exposure to uncontrolled environmental conditions in museums. To establish standard conditions for display of undyed and dyed silk fabrics in Egyptian museums, different artificial aging procedures (thermal, light and chemical) were applied to examine their effects on the physical, mechanical and chemical structure of the silk fiber. Samples of undyed silk and silk dyed with madder with different mordants, iron II sulphate; iron III chloride and copper sulphate were used for this purpose. These aged samples were examined for their surface morphology, color parameters (CIE Lab), mechanical properties, degree of crystallinity, secondary structure analysis and amino acids content.     

Hydrophobic and Flame-Retardant Foam Based on Cellulose

Journal of Polymers and the Environment - A study aimed to prepare cellulose-based hydrophobic, lightweight, and flame retardant foam composites. Cellulose was activated by phosphoric acid followed...     

Monitoring of linear alkyl benzenes (LABs) in riverine and estuarine sediments in Malaysia

Environmental Geochemistry and Health - The aim of this a pioneering research is to investigate linear alkylbenzenes (LABs) as biomarkers of sewage pollution in sediments collected from four rivers...