πSynthesis and evaluation of a series of α-hydroxy ethers derived from isopropyl oleate

Several fatty derivatives with bulky moieties were prepared by treatment of epoxidized isopropyl oleate with a number of alcohols in the presence of sulfuric acid catalyst to provide a series of α-hydroxy ethers in good yield. The materials were analyzed for cold flow performance through cloud point and pour point determinations. The most promising α-hydroxy ether produced in this study, with respect to both low temperature behavior and economic criteria, was isopropyl 9(10)-(2-ethylhexoxy) 10(9)-hydroxystearate, which has a cloud point of −23°C and pour point of −24°C.     

Determination of residual organic matter in extracted oil sands using a low temperature ashing method

The application of a low temperature ashing method for estimating total residual organic matter (toluene insolubles) in oil sands is described. A linear correlation exists between organic carbon content and loss on ignition at 400 ± 10 °C of solvent extracted oil sands. The ratio between total organic carbon and the weight loss on ignition (CT/LOl) owing to the removal of residual organic matter is much lower than that obtained for toluene soluble bitumen fractions, indicating very different chemical composition for the residual organic matter. The measured carbon content of the residual organic matter in oil sands suggests that this material could be a mixture of various fractions contained in resins, asphaltenes, asphaltic acids and humic acids.     

Radical styrene polymerization in the presence of trace levels of sulfonic acids

The bulk polymerization of styrene in the presence of the vinyl functional sulfonic acid 2‐sulfoethylmethacrylate (SEM) was found to have utility for making polystyrenes with narrow polydispersity, bimodal polydispersity, and ultrahigh molecular weight at fast polymerization rates. Narrow polydispersity polymers were made by the addition of SEM to nitroxide‐mediated polymerizations. Bimodal polydispersity polymers were made by the ultrahigh molecular weight component being made in the presence of SEM in the absence of an initiator and the low molecular weight component being made in the presence of an initiator and/or chain‐transfer agent. Ultrahigh molecular weight monomodal polystyrenes were prepared at much faster polymerization rates than possible via spontaneous polymerization in the absence of SEM. SEM was found to be more effective, by an order of magnitude, than camphor sulfonic acid on a weight basis and, because it is copolymerized into the polymer chain, should not lead to corrosion problems during fabrication of the polymer. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 869–875, 2003     

Chemical Defense in the Plant Bug Lopidea robiniae (Uhler)

Secretions from the metathoracic glands (MTG) of the black locust bug, Lopidea robiniae (Uhler) (Heteroptera: Miridae) contained six major compounds, including (E)-2-hexenal, (E)-2-hexen-1-ol, (E)-2-octenal, (E)-2-octen-1-ol (E)-2-heptenal, and (Z)-3-octen-1-ol. Males and females did not differ significantly in the relative compositions of identified compounds. In feeding trials, six bird species [robin (Turdus migratorious), blue jay (Cyanocitta cristata), brown thrasher (Toxostoma rufum), killdeer (Charadrius vociferus), starling (Sturnus vulgaris), and house wren (Troglodytes aedon)] demonstrated feeding aversions towards L. robiniae, implying that black locust bugs are chemically defended. Bugs discharged the liquid contents of their MTG when attacked, thereby producing a strong and distinct odor. Some birds immediately ejected bugs out of their mouth after biting them, suggesting that the MTG secretion was a deterrent.     

Production of Industrially Useful and Renewable p-Cymene by Catalytic Dehydration and Isomerization of Perillyl Alcohol

We report the dehydration and isomerization of renewable perillyl alcohol to industrially useful p-cymene in 91% yield utilizing 2.0 mol% para-toluenesulfonic acid (pTsOH) catalyst at 110 °C as a 3.0 M solution in toluene. Lower reaction temperatures, catalyst loadings, and/or starting concentrations resulted in lower yields of p-cymene as well as longer reaction times. Conversion of perillyl alcohol to p-cymene yielded atom and carbon economies of 88.1% and 100% as well as an E-factor of 2.7, thereby indicating that the process was both green and sustainable. A lower yield of 86% was observed when the reaction was performed neat, but a lower E-factor of 0.4 indicated that neat conditions were more desirable from an environmental perspective. Application of the optimized parameters to 3.0 M solutions of dl-limonene led predominantly to oligomerization (92%) as opposed to dehydroisomerization (5%), which was attributed to the strong Brønsted acidity of pTsOH. In addition, camphene (44%), terpinene isomers (15%), and limonene (14%) were obtained when dehydroisomerization was attempted on 3.0 M solutions of α- and β-pinene, which was once again attributed to the acidity of the catalyst. Oligomerization was strongly favored when dehydroisomerization of dl-limonene, α- and β-pinene was attempted neat. In summary, synthesis of renewable p-cymene was readily achieved from perillyl alcohol with catalytic pTsOH but competing side reactions suppressed yield when dehydroisomerization of dl-limonene, α- and β-pinene was attempted due to the strong Brønsted acidity of the catalyst.     

Using k-nn and discriminant analyses to classify rain forest types in a Landsat TM image over northern Costa Rica

Conservation and land use planning in humid tropical lowland forests urgently need accurate remote sensing techniques to distinguish among floristically different forest types. We investigated the degree to which floristically and structurally defined Costa Rican lowland rain forest types can be accurately discriminated by a non-parametric k nearest neighbors (k-nn) classifier or linear discriminant analysis. Pixel values of Landsat Thematic Mapper (TM) image and Shuttle Radar Topography Mission (SRTM) elevation model extracted from segments or from 5 × 5 pixel windows were employed in the classifications. 104 field plots were classified into three floristic and one structural type of forest (regrowth forest). Three floristically defined forest types were formed through clustering the old-growth forest plots (n = 52) by their species specific importance values. An error assessment of the image classification was conducted via cross-validation and error matrices, and overall percent accuracy and Kappa scores were used as measures of accuracy. Image classification of the four forest types did not adequately distinguish two old-growth forest classes, so they were merged into a single forest class. The resulting three forest classes were most accurately classified by the k-nn classifier using segmented image data (overall accuracy 91%). The second best method, with respect to accuracy, was the k-nn with 5 × 5 pixel windows data (89% accuracy), followed by the canonical discriminant analysis using the 5 × 5 pixel window data (86%) and the segment data (82%). We conclude the k-nn classifier can accurately distinguish floristically and structurally different rain forest types. The classification accuracies were higher for the k-nn classifier than for the canonical discriminant analysis, but the differences in Kappa scores were not statistically significant. The segmentation did not increase classification accuracy in this study.     

Runtime support for scalable programming in Java

The paper research is concerned with enabling parallel, high-performance computation—in particular development of scientific software in the network-aware programming language, Java. Traditionally, this kind of computing was done in Fortran. Arguably, Fortran is becoming a marginalized language, with limited economic incentive for vendors to produce modern development environments, optimizing compilers for new hardware, or other kinds of associated software expected of by today’s programmers. Hence, Java looks like a very promising alternative for the future. The paper will discuss in detail a particular environment called HPJava. HPJava is the environment for parallel programming—especially data-parallel scientific programming—in Java. Our HPJava is based around a small set of language extensions designed to support parallel computation with distributed arrays, plus a set of communication libraries. A high-level communication API, Adlib, is developed as an application level communication library suitable for our HPJava. This communication library supports collective operations on distributed arrays. We include Java Object as one of the Adlib communication data types. So we fully support communication of intrinsic Java types, including primitive types, and Java object types.     

Managing supply systems with partial information on shipment locations

This paper studies a supply system for a retailer who orders a single product from one manufacturer. Orders filled by the manufacturer pass through multiple transportation stages before reaching the retailer. Each stage represents either a physical location or a step in the delivery process. The lead time for a new order depends on the location of shipments against prior orders in transit. Shipments are not allowed to cross over in time. Thus, the movement of each shipment depends on the movements of shipments ahead of it and the resulting congestion. The retailer is able to track shipments as they move through the transportation channel. The retailer adopts an ordering policy that minimises the sum of his one-period holding and shortage costs, using available status information of shipments already in transit. The case where practical constraints prevent the retailer from obtaining a complete status of shipments at all stages in the transportation channel is considered. The methodology developed evaluates the value of partial shipment tracking information, and uses it to determine the optimal placement of a limited number of tracking devices. The methodology can also be used to evaluate the cost–benefit of placing additional tracking devices in the supply system.