Solubility parameters of hydrocarbons

Information available in the literature on vapor pressures, saturated vapor and liquid densities, and critical constants, for different hydrocarbons, has permitted the calculation of δ, the solubility parameter advanced by Hildebrand, at temperatures up to and including the critical point. For these hydrocarbons, the residual quantity, δ-δ_c was found to depend on 1-T_R according to the relationship, where k appears to be a constant within different classes of hydrocarbons. Values of δ calculated with this equation were compared with the corresponding values used to develop it, and produced an average deviation of 0.85% for 153 values considered which represented 17 hydrocarbons.     

Effect of polymerization conditions on the melt rheological properties of vinyl chloride–vinyl acetate copolymers

Mathematical models have been developed which predict the composition, molecular weight, and melt rheological properties for vinyl chloride/vinyl acetate copolymers of inherent viscosity range 0.4–0.7 dL/g and bound vinyl acetate levels of 3.8–17.4%. The effect of polymer long chain branching on the viscous/elastic moduli ratio is discussed as well as the comparison of Tinius–Olsen melt index measurements vs. mechanical spectrometer results. The reactivity ratio for vinyl chloride/vinyl acetate comonomer pairs was remeasured and found to be significantly different from literature values.     

Chemical characterization of the mutagenic neutral aromatic polar fractions of petroleum substitutes

The constituents of the neutral aromatic polar subfractions of two coal-derived oils, a shale-derived oil and a petroleum oil were analysed and compared. Chemical ionization mass spectra, using methanol and ammonia as reagent gases, were used to characterize the oxygen-and nitrogen-containing constituents, respectively. The compositions of the petroleum substitutes were found to differ from those of petroleum in containing primary polycyclic aromatic amines, azaarenes, polycyclic hydroxyaromatics and, in one case, aromatic ketones.     

Molecular mass calibration in size-exclusion chromatography of coal derivatives

A number of procedures have been investigated for the calibration of a size-exclusion chromatography (s.e.c.) column in the determination of molecular mass (MM) distributions of coal derivatives. The behaviour of narrow fractions of coal extracts in the MM range 200–3000 was compared with a variety of the more generally available calibration standards. Calibration with preparative s.e.c. subfractions of materials similar to those under study has been recommended. Polystyrene standards are satisfactory, however, for MM < 1000, but above this range other polymer standards should be sought. Universal and molar volume calibration do not apply to coal-derived materials.     

Lack of enantioselective microbial degradation of chlordane in Long Island Sound sediment

Numerous studies have examined the enantiomeric compositions of trans- and cis-chlordane in soils (agricultural, background, and house foundation soils) and in the atmosphere. In contrast, little is known aboutthe enantiomeric compositions of chlordane in sediment. In this work, surficial sediments and sediment cores were collected at various sites in Long Island Sound (LIS) previously surveyed by the National Oceanic and Atmospheric Administration's (NOAA) National Status and Trends (NS&T) Program. Archived surficial sediments at selected sites were acquired from the NS&T Specimen Bank. The chlordanes were racemic or nearly racemic in most archived and recently collected sediments, indicating thatthe enantiomeric compositions of the sources of chlordane to LIS sediment did not change in the past two decades, and that house foundation soils are likely the major source of chlordanes to LIS. Invariant enantiomeric compositions temporally in surficial sediments and at different depths in sediment cores clearly indicate the lack of enantioselective biodegradation in LIS sediment, in striking contrast to the widely observed enantioselective biodegradation of chlordanes in soils.     

Influence of feeding Mediterranean food industry by-products and forages to Awassi sheep on physicochemical properties of milk, yoghurt and cheese

Feeding agro-industrial by-products and unconventional forages, rich in potentially anti-nutritional factors, may influence the quality of the raw milk and the dairy products prepared therefrom. The aim of the present study was to determine side-effects on physicochemical properties of milk, yoghurt and cheese of feeding diets where one third were feeds either rich in lipids (tomato pomace and olive cake) or phenols (olive leaves and lentil straw) or electrolytes (Atriplex leaves). The diets, including a control diet, were designed to be isoenergetic and isonitrogenous. They were fed in amounts of 25 kg dry matter/day per head during 50 days to 6×10 multiparous fat-tailed Awassi ewes. Milk samples were analysed for various physicochemical traits and fatty acid composition on days 0, 24, 36 and 48. Three times, milk pooled by group was processed to yoghurt and non-aged farmer-type cheese, which were analysed for their gross and fatty acid composition and texture, and were subjected to sensory evaluation. Feeding olive cake and tomato pomace reduced milk casein, but increased proportions of monounsaturated fatty acids. There were some variations in minerals among test diets but, contrary to expectations, Atriplex did not increase milk sodium. The nutritional composition of yoghurt and cheese was not varied much by the test feeds, except for some changes in fatty acid profile similar to the milk. Yoghurt firmness declined with all test diets, but texture score tended to be lower only for olive cake and leaf diets relative to control. Cheese firmness was increased by feeding the Atriplex leaf and olive cake diets which was also reflected in the texture scores. No off-flavours were reported. Possible reasons for effects on the dairy products are discussed. In conclusion, the feeds investigated had certain effects on the physicochemical properties of dairy products, but these were neither very systematic nor large thus not prohibiting their use in Mediterranean sheep milk production systems.     

Recovery of phenanthrene-degrading bacteria after simulated in situ persulfate oxidation in contaminated soil

A continuous-flow column study was conducted to investigate the long-term effects of persulfate oxidation on the abundance and activity of the indigenous microbial community and phenanthrene-degrading bacteria in contaminated soil from a former manufactured gas plant (MGP) site. Approximately six pore volumes of a 20 g/L persulfate solution were introduced into the column, followed by simulated groundwater for 500 days. Soil samples were collected from the surface of the soil bed and along the column length immediately before and after persulfate injection and up to 500 days following injection. Exposure to persulfate led to a 2- to 3-log reduction in total bacterial 16S rRNA genes, severe inhibition of (14)C-acetate mineralization (as a measure of general microbial activity), and a decrease in community diversity. However, relatively rapid recovery of both bacterial gene abundance and activity was observed within 30 days after persulfate exposure. Mineralization of (14)C-phenanthrene was also inhibited but did not recover until 100 days postoxidation. Known phenanthrene-degrading bacterial groups decreased to below detection limits throughout the column, with recovery times from 100 to 500 days after persulfate injection. These findings suggest that coupling biological processes with persulfate oxidation is possible, although recovery of specific contaminant degraders may occur much later than the general microbial community recovers. Furthermore, the use of total bacterial quantity or nonspecific measures of activity as a surrogate for the recovery of contaminant degraders may be inappropriate for evaluating the compatibility of chemical treatment with subsequent bioremediation.     

c9t11‐Conjugated linoleic acid‐rich oil fails to attenuate wasting in colon‐26 tumor‐induced late‐stage cancer cachexia in male CD2F1 mice

Scope: Cancer cachexia is characterized by muscle and adipose tissue wasting caused partly by chronic, systemic inflammation. Conjugated linoleic acids (CLAs) are a group of fatty acids with various properties including anti‐inflammatory cis9, trans11 (c9t11)‐CLA and lipid‐mobilizing trans10, cis12 (t10c12)‐CLA. The purpose of this study was to test whether dietary supplementation of a c9t11‐CLA‐rich oil (6:1 c9t11:t10c12) could attenuate wasting of muscle and adipose tissue in colon‐26 adenocarcinoma‐induced cachexia in mice. Methods and results: Loss of body weight, muscle and adipose tissue mass caused by tumors were not rescued by supplementation with the c9t11‐CLA‐rich oil. In quadriceps muscle, c9t11‐CLA‐rich oil exacerbated tumor‐induced gene expression of inflammatory markers tumor necrosis factor‐α, IL‐6 receptor and the E3 ligase MuRF‐1 involved in muscle proteolysis. In epididymal adipose tissue, tumor‐driven delipidation and atrophy was aggravated by the c9,t11‐CLA‐rich oil, demonstrated by further reduced adipocyte size and lower adiponectin expression. However, expression of inflammatory cytokines and macrophage markers were not altered by tumors, or CLA supplementation. Conclusion: These data suggest that addition of c9t11‐CLA‐rich oil (0.6% c9t11, 0.1% t10c12) in diet did not ameliorate wasting in mice with cancer cachexia. Instead, it increased expression of inflammatory markers in the muscle and increased adipose delipidation.     

On the role of 2,3-dihydro-3,5-dihydroxy-6-methyl-(4<Emphasis Type="Italic">H</Emphasis>)-pyran-4-one in antioxidant capacity of prunes

Despite available reports on phenolic composition and antioxidant capacity (AOC) of fresh plums and prunes, there is a scarcity of published knowledge on the antioxidants formed and/or released during the drying process in the literature. To evaluate the compounds participating in reducing capacity of prunes, we compared aqueous and methanol extracts of fresh plums, commercial prunes and home-made prunes prepared at different drying temperatures using an HPLC method with amperometric detection (HPLC-ECD). The prunes dried at high temperature (90 °C, 18 h) in kitchen or laboratory oven with restricted ventilation gave up to 3.3 times higher electrochemical capacity (EC) than fresh plums (dry matter; P. domestica cv. Domestica) in dependence on production protocol. Drying at 60 °C (low-temperature drying) for 18 h did not change the EC significantly. Yet, lower EC was found in commercial tenderized prunes with sorbate; they were by a factor of 1.1–8.2 lower in EC than the prepared low-temperature prunes. The principle responsible for the increase in EC in the prunes prepared at high temperatures is 2,3-dihydro-3,5-dihydroxy-6-methyl-(4H)-pyran-4-one (DDMP). It was not detected until 74 °C was set during isothermal 18 h drying or until 6 h of drying passed at 90oC drying. The ultimate acceptable dwell-time for the preparation of conveniently eatable prunes dried at 90oC under the conditions used was assessed to 12 h. The EC of plums and prunes as well as the role of DDMP was confirmed by the use of several methods for the assessment of AOC-DPPH^• assay, β-carotene bleaching method, Oxipres test and Schaal oven test.