Determination of heavy metals and volatile aromatic compounds in used engine oils and sludges

Assessment of contaminant releases during utilization of used oils is essential for the determination of environmental acceptability. These paper reports the results of the study examining a toxic metal leachability from used engine oil and sludge samples employing leaching test (TCLP). The leaching test indicated that lead in oil samples exceeded 5-ppm concentration level what qualified them as a toxic waste. The samples of contaminated sludge were found to contain high concentration of total lead, barium and chromium, but the leaching test showed concentration below regulatory limit. The total content of benzene, ethylbenzene, toluene, and xylenes (BETX), and naphthalene in used oil and sludge samples was also determined and was found not to be a significant factor to contamination.     

Non-Isothermal crystallization of isotactic polypropylene in dotriacontane. I: Effects of dilution,cooling rate,and nucleating agent addition on overall crystallization kinetics

The overall non-isothermal crystallization kinetics for nucleated and non-nucleated isotactic polypropylene (iPP) in dotriacontane systems was investigated. Adipic acid was used as the nucleating agent. Crystallization peak temperature was determined via differential scanning calorimetry as a function of the experimentally controlled variables iPP concentration, cooling rate, and nucleating agent concentration. The influence of these variables on crystallization mechanism and spherulitic structure as implied by the Ozawa and Ziabicki analyses was determined. The non-isothermal crystallization kinetics presented here are the first for iPP-diluent systems with and without nucleating agent.     

Synthesis and characterization of maltose fatty acid monoesters as biosurfactants

Maltose long-chain fatty acid esters (MFAE), esterified at the 6 and 6′ position, were synthesized with stearic, palmitic, myristic, and oleic groups. Synthesis yields were 15–20% based on initial maltose present, and structural confirmation was obtained using plasma desorption mass spectrometry and nuclear magnetic resonance spectroscopy. These surfactants have surface tensions in the range of 34–36 dyn/cm at their critical micelle concentrations (CMC) of approximately 10⁻⁵–10⁻⁶ mol/L. The increased chain lengths have a marked effect, reducing CMC values for MFAE by approximately three orders of magnitude over similar carbohydrate-based dodecyl chain sources. Within chain lengths between 14 and 18 carbons, the rate of change in CMC is significant and decreases with increasing chain length for MFAE. The melting points of MFAE are approximately 40°C, and the heat capacities range from 1.6 to 1.9 J/g·K. These numbers are comparable to those of sucrose esters, indicating their applicability in similar uses. However, because MFAE, unlike sucrose, possess an anomeric carbohydrate carbon position, these surfactants maintain their reducing nature and are susceptible to further derivatization. They are also synthesized from renewable, economical carbohydrates and lipids and may provide an excellent alternative to pertrochemical-derived products.     

Replacement of dietary fish oil with increasing levels of linseed oil: Modification of flesh fatty acid compositions in Atlantic salmon (<Emphasis Type="Italic">Salmo salar</Emphasis>) using a fish oil finishing diet

Five groups of salmon, of initial mean weight 127±3 g, were fed increasing levels of dietary linseed oil (LO) in a regression design. The control diet contained capelin oil (FO) only, and the same oil was blended with LO to provide the experimental diets. After an initial period of 40 wk, all groups were switched to a finishing diet containing only FO for a further 24 wk. Growth and flesh lipid contents were not affected by dietary treatment. The FA compositions of flesh total lipids were linearly correlated with dietary FA compositions (r ²=0.88–1.00, P<0.0001). LO included at 50% of added dietary lipids reduced flesh DHA and EPA (20∶5n−3) concentrations to 65 and 58%, respectively, of the concentrations in fish fed FO. Feeding 100% LO reduced flesh DHA and EPA concentrations to 38 and 30%, respectively, of the values in fish fed FO. Differences between diet and flesh FA concentrations showed that 16∶0, 18∶1n−9, and especially DHA were preferentially retained in flesh, whereas 18∶2n−6, 18∶3n−3, and 22∶1n−11 were selected against and presumably utilized for energy. In fish previously fed 50 and 100% LO, feeding a finishing diet containing FO for 16 wk restored flesh DHA and EPA concentrations, to ≈80% of the values in fish fed FO throughout. Flesh DHA and EPA concentrations in fish fed up to 50% LO were above recommended intake values for humans for these EFA. This study suggests that LO can be used as a substitute for FO in seawater salmon feeds and that any reductions in DHA and EPA can be largely overcome with a finishing diethigh in FO before harvest.     

Kinetics of droplet growth in liquid—liquid phase separation of polymer—diluent systems: experimental results

Liquid—liquid thermally induced phase separation of the polymer—diluent system isotactic poly(propylene)—diphenyl ether was studied under an optical microscope. It was found that as the system phase separated, droplets of a diluent-rich phase formed within a polymer-rich matrix. These droplets grew in size and decreased in number by a process known as coarsening. The scaling exponent relating droplet diameter and time was determined. The scaling exponent was found to be a strong function of the droplet phase volume fraction, and this strong dependence on volume fraction was relatively insensitive to temperature. The influence of the ratio of interfacial tension between the phases and the viscosity of the matrix phase was less significant on the growth rate of the droplets.     

A generalist herbivore in a specialist mode Metabolic,sequestrative, and defensive consequences

Adults of a generalist herbivore, the lubber grasshopper,Romalea guttata, can be converted to functional specialists by feeding them exclusively on catnip,Nepeta cataria. No obvious adverse effects on adult development resulted from this enforced monophagy. Notwithstanding the fact thatR. guttata has had no coevolutionary relationship with this Eurasian mint, it readily sequesters compounds that are identical to or derived from the terpenoid lactones that are characteristic ofN. cataria. R. guttata appears to both biomagnify minor allelochemicals and to sequester metabolites of theNepeta terpenes in its paired defensive glands. The levels of autogenously produced phenolics are not affected by feeding onN. cataria and the defensive secretions of catnip-fed grasshoppers are more repellent to ants than those of wild-fed acridids. Metabolites of theN. cataria monoterpenes are sequestered in the defensive glands when catnip is added to the natural diet ofR. guttata. The ability of a generalist,R. guttata, to facilely bioaccumulate a potpourri of foreign allelochemicals when feeding in a specialist mode is analyzed in terms of its biochemical, physiological, and functional significance. Sequestration is examined as a response to the enteric effronteries represented by the phytochemicals that can be characteristic of the overload in a monophagous diet.     

Surface Tension of Calcium Aluminosilicate Glass Using Computerized Drop Shape Analysis

Numerical analysis is used in this study to derive surface tension from the shape of a liquid silicate sessile drop. The speed afforded by the drop shape analysis package facilitates analysis of experimentally derived drop profiles. Drop symmetry, contact angles, and local shape variations can be readily determined, thereby permitting the detection of experimental errors. The experimental and analytical technique was first validated by determining the surface tension of high-purity gallium and aluminum under carefully controlled furnace atmospheres. Results for a calcium aluminosilicate melt are compared to pendant drop and maximum-bubble pressure measurements reported in the literature. The use of an internal scaling factor and the effect of substrate interactions are discussed.     

Carbonization and liquid-crystal (mesophase) development. 12. Mechanisms of the co-carbonization of coals with organic additives

In industrial situations, coals interact with solvents or additives to produce liquid fuels, solvent-refined coal, coal extract and metallurgical coke. In these processes there occurs a wide variation in effects or modifications of the coal by these additives. This paper describes the modifications which can occur, using a wide range of rank of coal, when these coals interact and are co-carbonized with a wide range of additives of different chemical properties. The optical texture of the resultant cokes is given special attention. The objective of the paper is to summarize the current state of knowledge of the mechanisms of these interactions. Possible mechanisms of interactions are summarized, kinetic and chemical structural aspects of reactions are outlined, the importance is mentioned of the formation of liquid phases enabling anisotropic optical textures in modified cokes to be created, and the industrial relevance of its possible development is discussed.     

Baseballs and arguments from fairness

This paper applies two argumentation schemes, argument from fairness and argument from lack of knowledge (along with other schemes of lesser prominence) to model the reasoning given by Judge McCarthy supporting his decision to divide the proceeds of a homerun baseball in the case of Popov v. Hayashi. Several versions of both schemes are explained and discussed, and then applied to the argumentation given by Judge McCarthy as the basis of the reasoning used to arrive at his decision. The scheme for argument from fairness is shown to be based on a special principle in Perelman’s theory of justice.     

Ketone bodies,glucose and glutamine as lipogenic precursors in human diploid fibroblasts

Incorporation of [¹⁴C] from acetoacetate, D(-)- and L(+)-3-hydroxybutyrate, glucose, glutamine, acetate and palmitate in cellular lipids were studied in cultures in human diploid fibroblasts (HDF). The results showed that acetoacetate was 2–10 times more effective as a lipogenic precursor than was either D- or L-3-hydroxybutyrate. Its extent of incorporation into lipids was 2- to 8-fold more than the other precursors examined under conditions when the overall rates of nonsaponifiable and saponi-fiable lipogenesis as measured by³H₂O incorporation were essentially unchanged. Acetoacetate supported both saponifiable and nonsaponifiable lipid syntheses with half-saturation values (K_m app.) of 185 μM and 30 μM, respectively. Glucose stimulated acetoacetate incorporation into lipids whereas, conversely, acetoacetate inhibited [¹⁴C] glucose incorporation into lipids. The presence of low density lipoproteins (LDL) cholesterol (@40 μg cholesterol/mL) inhibited the incorporation of [¹⁴C] from acetoacetate 56% into nonsaponifiable lipids; the inhibition was consistently higher (75%) when [¹⁴C] glucose or glutamine were the precrusors. The loss of 3-hydroxy-3-methyl-glutaryl CoA (HMG CoA) reductase activity upon addition of LDL-cholesterol was greater than the suppression of [¹⁴C] incorporation from acetoacetate or glucose into nonsaponifiable lipids. In the presence of glucose, [¹⁴C] acetoacetate was incorporated into 3-βOH sterols (digitonin precipitable). 7.7±1.1 times more effectively than was [¹⁴C] glucose. The results suggest that HDF would be a suitable model to investigate the effects of various precrusors of HMG CoA on the rate of cholesterol biosynthesis.