Ag-ZnO catalysts for UV-photodegradation of methylene blue

High surface area Ag-ZnO catalysts have been made by flame spray pyrolysis (FSP) and characterized by X-ray diffraction (XRD), nitrogen adsorption, UV–vis spectroscopy and electron microscopy (SEM and transmission electron microscopy (TEM)) combined with energy dispersive X-ray spectroscopy (EDXS) for elemental mapping. Silver metal clusters deposited directly on ZnO nanocrystals were obtained from this process. The Ag loading (1–5 at.%) controlled the Ag cluster size from 5 to 25 nm but did not influence the ZnO crystal size. Photodegradation of 10 ppm methylene blue (MB) solution was used to evaluate the performance of these FSP-made Ag-ZnO and was compared to wet-made Ag-ZnO and reference titania photocatalysts. The rate of photodegradation was optimal for Ag loading around 3 at.%. The best photocatalytic performance was exhibited by flame-made Ag-ZnO produced at the longest high-temperature residence times having high crystallinity as determined by XRD and UV–vis.     

The roles of nitrogen,phosphorus and Potassium in the production of sugarcane in South Africa

The amounts of N and K fertilizers used in the South African sugar industry have increased dramatically in the past four decades, due partly to an increase in the area under sugarcane but also to large increases in the amounts of N and K fertilizers applied per hectare. There has also been an increase in the amount of P fertilizer used but this has been more gradual. The main fertilizer carriers for cane and their relative efficiency are discussed. During this period there has been considerable research into the nutrient requirements of sugarcane. Correlations established between soil and leaf analysis and crop responses to N, P and K fertilizers, and their effects on cane quality, are reviewed. While fertilizer recommendations based on soil and leaf analysis have provided a useful guide for determining the nutrient requirements of cane, they are continually being modified in the light of current research.     

Role of metal ion impurities in generation of oxygen gas within anodic alumina

The generation of oxygen gas within an amorphous anodic alumina film is reported. The film was formed by anodizing aluminum, which was first electropolished and then chemically polished in CrO₃-H₃PO₄ solution, in sodium tungstate electrolyte. The procedure results in incorporation of mobile Cr³⁺ species, from the chemical polishing film, and mobile W⁶⁺ species, from the electrolyte, into the amorphous structure. The tungsten species are present in the outer 27% of the film thickness, while Cr⁶⁺ species occupy a thin layer within the tungsten-containing region. Above the Cr³⁺ containing layer, a band develops that contains oxygen bubbles of a few nanometres size. The oxygen is generated by oxidation of O²⁻ ions of the alumina. A mechanism of oxygen generation within the alumina is proposed based on the electronic band structure of the oxide, modified by the Cr³⁺ and W⁶⁺ species, and on the ionic transport processes during oxide growth.     

Diterpene resin acids: Major active principles in tall oil against Variegated cutworm,Peridroma saucia (Lepidoptera: Noctuidae)

Tall oil, a by-product of the kraft process for pulping softwood, has been shown to have insecticidal properties. In the present study, the active principles in tall oil against the variegated cutworm,Peridroma saucia Hübner, were investigated. GC-MS analysis showed that abietic, dehydroabietic, and isopimaric acids were major resin acid components of crude tall oil and depitched tall oil. When crude tall oil samples of differing resin acid composition were incorporated into artificial diet at a concentration of 2.0% fresh weight, they suppressed larval growth by 45–60% compared to controls. This suppression was significantly (P0.05) correlated with the equivalent contents of abietic, dehydroabietic, isopimaric, and total resin acids. These results were also evident from a diet choice test, showing that the second-instar larvae obviously selected diets with low levels of resin acids when different diets were randomly arranged in a Petri dish. Bioassays with pure resin acids (abietic, dehydroabietic, and isopimaric acids) demonstrated that all individual chemicals have similar bioactivity against this insect. Comparison of the bioactivities of depitched tall oil and an equivalent mixture of pure resin acids in thePeridroma chronic growth bioassay indicated that pure resin acids and depitched tall oil share a common mode of action to this insect. This study confirms that resin acids are major active principles in tall oil against the variegated cutworm, but other chemicals likely also contribute to the bioactivity of tall oil.     

Analysis of the Insect OS-D-Like Gene Family

Insect OS-D-like proteins, also known as chemosensory (CSP) or sensory appendage proteins (SAP), are broadly expressed in various insect tissues, where they are thought to bind short to medium chain length fatty acids and their derivatives. Although their specific function remains uncertain, OS-D-like members have been isolated from sensory organs (including the sensillum lymph in some cases), and a role in olfaction similar to that of the insect odorant binding proteins (OBP) has been suggested for some. We have identified 15 new OS-D-like sequences: four from cDNA clones described herein and 11 from sequence databases. The os-d-like genes from the Anopheles gambiae, Apis mellifera, Drosophila melanogaster, and Drosophila pseudoobscura genomes typically have single, small introns with a conserved splice site. Together with all family members entered on GenBank, a total of 70 OS-D-like proteins, representing the insect orders Diptera, Dictyoptera, Hymenoptera, Lepidoptera, Orthoptera, and Phasmatodea, were analyzed. A neighbor joining distance phenogram identified several protein similarity classes that were characterized by highly conserved sequence motifs, including (A) N-terminal YTTKYDN(V/I)(N/D)(L/V)DEIL, (B) central DGKELKXX(I/L)PDAL, and (C) C-terminal KYDP. In contrast, three similarity classes were characterized by their diversion from these conserved motifs. The functional importance of conserved amino acid residues is discussed in relation to the crystal and NMR structures of MbraCSPA6.     

Terminal composition control of a binary distillation column

Terminal composition control of a pilot scale binary distillation column operated under the control of an IBM 1800 digital computer has been studied for disturbances in feed flow rate. Conventional two point control, whereby the overhead composition is controlled by reflux flow rate and bottom composition by means of steam rate, was demonstrated to be unsatisfactory. Two alternate control systems, namely a noninteracting control system and a ratio control system were evaluated. The noninteracting control system was constructed from a transfer function representation of the distillation column dynamics, determined from a series of on-line pulse tests. The results show that a very significant improvement in the control of both compositions is achieved by using noninteracting control or the ratio control scheme suggested by Rijnsdorp compared to the behavior that results using conventional two point feedback control. However, the control performance obtained using noninteracting control was only marginally better than that using the ratio control scheme.     

A comparison of lipids from liver and hepatoma subcellular membranes

Subcellular fractions of nuclei, mitochondria, endoplasmic reticulum, plasma membrane and cytosol were prepared from liver and hepatoma 72288CTC. Marker enzyme activities, biochemical compositions and electron microscopy were used to establish purity. Hepatoma NADH: cytochrome C reductase and 5′-nucleotidase exhibited abnormal subcellular distributions. The lipids from the subcellular fractions were examined in detail. Mitochondria and plasma membranes were characterized by elevated percentages of diphosphatidylglycrerol and sphingomyelin, respectively, in both tissues. All hepatoma subcellular fractions contained dramatically elevated levels of sphingomyelin and cholesterol, two components that form preferential strong complexes in vitro. The fatty acid composition of hepatoma sphingomyelin differed markedlg from liver and, unlike liver, did not exhibit organelle specific compositions. Some hepatoma lipid classes contained reduced percentages of palmitate while others contained higher levels. Hepatoma phosphatidylcholine and phosphatidylethanolamine from organelles contained lower percentages of long chain polyunsaturated fatty acids than liver. Generally, unique fatty acid profiles exhibited by individual phospholipid classes of liver subcellular fractions were absent or much reduced in the hepatoma. The ratios of oleate to vaccenate were near one for most of the phospholipid classes of most liver fractions, but all hepatoma classes, with few exceptions, contained a much higher percentage of oleate in all subcellular fractions. The hypothesis is proposed that the origin of some acyl moieties for the biosynthesis of various hepatome lipid classes differs from liver sources. The possible changes in acyl pools, sources and compartments for complex lipid biosynthesis could result in change in the quantities of molecular species that could contribute to the abnormal properties of the hepatoma membranes.     

Hedgerow species and environmental conditions effects on soil total C and N and C and N mineralization patterns of soils amended with their prunings

An important criterium in selecting species for alley cropping is themineralization pattern of their prunings. This study determined effects of 5years of hedgerow pruning applications on soil organic C and total N at threelocations in Haiti and mineralization patterns from soil amended with theprunings during an incubation using micro-lysimeters. Soils (0–5cm) under 5 hedgerows were collected at each site and analyzed fororganic C and total N. In the laboratory, ground leaves and stems (<1cm diameter) of the hedgerow species were mixed with soil at ratesof 3 and 1.5 Mg ha^–1, respectively, andaerobically incubated in the dark at 25 °C. A non-amended soilwas used as control. Soils were leached to determine mineral N at 1, 3, 7, 14,28, 42, 84 and 120 days of incubation. Evolved CO₂ was measuredfollowing each leaching procedure. At the calcareous site, application ofprunings from Leucaena leucocephala (Lam.) De Wit andDelonix regia (Boj. ex Hook. Raf.) resulted in 23 and 13%higher soil N than the control, respectively, after 5 years. There were nodifferences in total N at the other sites but soil N was highest underLeucaena hybrid and Acaciaangustissima (Mill.) Kuntze, respectively at the basaltic and highelevation sites. Soils under D. regia (calcareous) andA. angustissima and Leucaena hybrid(high elevation) had higher organic C than the respective controls. Carbon andNmineralization and C turnover were highest when soils were amended with leavesof Leucaena diversifolia (Schlecht.) Benth (calcareous andbasaltic soils) and A. angustissima (high elevation) andlowest in non-amended control soils. Stem-amended soils showed differences in Cmineralization for calcareous and high elevation soils whereas N mineralizationwas similar among treatments within sites. Carbon and N mineralization (highelevation soil) correlated positively with N concentrations of leaf prunings.Amendments with leaf prunings increased soil C and N mineralization andturnoverrates, suggesting greater nutrient availability for the crop during a shortperiod than in non-amended control soils.     

The role of fats and oils in cosmetics

The earliest emollients in the history of cosmetics were the naturally occurring animal fats and vegetable oils. These provided soothing and smoothing action on the skin and grooming effects on head and beard hair. For the most part, odor problems limited the interest in oils derived from fish. With the increasing sophistication of users and increasing understanding of the technology of these materials, the short-comings of natural fats and oils were overcome in several ways: (a) increased stability through use of antioxidants; (b) reduced odor through improved processing; (c) improved stability and diversification through chemical modification; (d) increased diversity through preparation of derivatives, and (e) substitution of mineral oil. Today the most important single cosmetic use of an unmodified natural fat or oil is that of castor oil as the base for lipsticks. Other unmodified oils have largely minor specialty uses, particularly in higher-priced cosmetics. These include almond oil, apricot kernel oil, sesame oil, safflower oil, wheat germ oil, avocado oil, turtle oil and mink oil. Cocoa butter is used to some extent in suntan products. Reconstituted fractionated coconut oil is widely used. Polyglycerol esters of fatty acids are increasing in importance. Hydrogenation has produced stable oils useful in cosmetics. Alkyl esters and monoglycerol esters of fatty acids offer a wider range of properties than the original oils. Improvements in the naturally occurring fats and oils have made it possible for them to compete in some characteristics, and current interest in “natural” cosmetics may turn the attention of the cosmetic chemist back to improved versions of the classical raw materials. One of five papers in the symposium “Fats and Oils in Cosmetics and Pharmaceuticals,” presented at the AOCS Meeting, Atlantic City, October 1971.     

Intercorrelations among plasma high density lipoprotein,obesity and triglycerides in a normal population

The interrelationships among fatness measures, plasma triglycerides and high density lipoproteins (HDL) were examined in 131 normal adult subjects: 38 men aged 27–46, 40 men aged 47–66, 29 women aged 27–46 and 24 women aged 47–66. None of the women were taking estrogens or oral contraceptive medication. The HDL concentration was subdivided into HDL_2b, HDL_2a and HDL₃ by a computerized fitting of the total schlieren pattern to reference schlieren patterns. Anthropometric measures employed included skinfolds at 3 sites, 2 weight/height indices and 2 girth measurements. A high correlation was found among the various fatness measures. These measures were negatively correlated with total HDL, reflecting the negative correlation between fatness measures and HDL₂ (as the sum of HDL_2a and_2b). Fatness measures showed no relationship to HDL₃. There was also an inverse correlation between triglyceride concentration and HDL₂. No particular fatness measure was better than any other for demonstrating the inverse correlation with HDL but multiple correlations using all of the measures of obesity improved the correlations. Partial correlations controlling for fatness did not reduce any of the significant correlations between triglycerides and HDL₂ to insignificance. The weak correlation between fatness and triglycerides was reduced to insignificance when controlled for HDL₂. Presented (in part) at the Annual Meeting of the Oil Chemists' Society in St. Louis, MO, May 1978.