Model representation of secondary organic aerosol in CMAQv4.7

Numerous scientific upgrades to the representation of secondary organic aerosol (SOA) are incorporated into the Community Multiscale Air Quality (CMAQ) modeling system. Additions include several recently identified SOA precursors: benzene, isoprene, and sesquiterpenes; and pathways: in-cloud oxidation of glyoxal and methylglyoxal, particle-phase oligomerization, and acid enhancement of isoprene SOA. NO(x)-dependent aromatic SOA yields are also added along with new empirical measurements of the enthalpies of vaporization and organic mass-to-carbon ratios. For the first time, these SOA precursors, pathways and empirical parameters are included simultaneously in an air quality model for an annual simulation spanning the continental U.S. Comparisons of CMAQ-modeled secondary organic carbon (OC(sec)) with semiempirical estimates screened from 165 routine monitoring sites across the U.S. indicate the new SOA module substantially improves model performance. The most notable improvement occurs in the central and southeastern U.S. where the regionally averaged temporal correlations (r) between modeled and semiempirical OC(sec) increase from 0.5 to 0.8 and 0.3 to 0.8, respectively, when the new SOA module is employed. Wintertime OC(sec) results improve in all regions of the continental U.S. and the seasonal and regional patterns of biogenic SOA are better represented.     

Physico‐chemical characterization of date varieties using multivariate analysis

BACKGROUND: The fruit of date palm is consumed as an ideal high‐energy food. It is also used for the treatment of colds, fever, liver and abdominal troubles. Its nutritional composition strongly depends upon variety and ripening stage. A number of varieties are available in Pakistan but little is known about their composition and nutritional characteristics. Inherent moisture, volatile matter, ash, fixed carbon, sugar and mineral metals of seven commercial date varieties (Aseel, Basra, Begun, Janshoor, Mazoee, Rabee and Zaidi) were investigated. The physical and chemical compositions with respect to maturation were also monitored for the Aseel variety. RESULTS: The results showed significant varietal differences in moisture, ash and mineral metal composition when analysis of means was conducted at an alpha level of 0.05. The difference between means was insignificant (P > 0.05) for volatile matter, glucose, fructose and total reducing sugars. All varieties were found to be an excellent source of total reducing sugar (78%), potassium (403–632 mg per 100 g) and calcium (27.41–81.47 mg per 100 g). A gradual increase in total reducing sugar and minerals, especially potassium and copper, was observed with maturation. Variety Aseel was grouped on the basis of maturation using principal component analysis. Local date varieties were separated with 48.63% level of similarity from Iranian variety (29.17%) using Cluster analysis. CONCLUSION: This study provides an overview of the physico‐chemical properties of date varieties. The sample varieties showed significant differences except for sugar and volatile matter. Multivariate analysis was found to be an important statistical tool for the separation of samples on the basis of geographical origin and maturations. Copyright © 2008 Society of Chemical Industry     

Parallel query execution over encrypted data in database-as-a-service (DaaS)

The Journal of Supercomputing - The main challenge in database-as-a-service is the security and privacy of data because service providers are not usually considered as trustworthy. So, the data...     

Amine-terminated aromatic and semi-aromatic hyperbranched polyamides: synthesis and characterization

A facile synthetic approach to aromatic and semiaromatic amine-terminated hyperbranched polyamides via direct polymerization of triamine (B₃) with different diacid chlorides (A₂) was explored. An aromatic triamine, 1,3,5-tris(4′-aminophenylcarbamoyl)benzene (TAPCB), was synthesized and monomers were characterized by elemental analysis, FTIR, ¹H and ¹³C NMR spectroscopy. Finally, the polycondensation reaction of TAPCB with terephthaloyl chloride (TPC), isophthaloyl chloride (IPC), sebacoyl chloride (SC) and adipoyl chloride (AC) resulted in the preparation of four hyperbranched polyamides i.e., HBPA 1, 2, 3 and 4, respectively. FTIR and ¹H NMR analyses confirmed the structures of the ensuing polymers and DB was found between 0.51–0.55. These thermally stable amorphous HBPAs were soluble in polar aprotic solvents at room temperature having glass transition temperatures (T_g) between 138–198 °C. Inherent viscosities (η_inh) and weight average molecular weights (M_w) were in the range of 0.27–0.35 dL/g and 1.3 × 10⁴–2.7 × 10⁴, respectively. Future prospects are envisaged.     

Enrichment,in vitro,and quantification study of antidiabetic compounds from neglected weed Mimosa pudica using supercritical CO2 and CO2-Soxhlet

Supercritical fluid extraction (SFE) using carbon dioxide (CO₂) and liquid CO₂ using Soxhlet (CO₂-Soxhlet) extraction were employed to extract three (3) antidiabetic compounds viz. stigmasterol, quercetin, and avicularin from Mimosa pudica. Various extraction parameters were studied. Extracts were analyzed pharmacologically, qualitatively and quantitatively to ascertain enrichment levels. All three antidiabetic compounds were effectively enriched under optimized conditions of temperature 60°C, pressure 40 MPa, co-solvent ratio 30%, and CO₂ flow rate of 5 ml min^?1. SFE was found to be the better method for enrichment of the antidiabetic compounds than the CO₂-Soxhlet method. Extraction conditions were seen to affect the enrichment of desired compounds.     

Improvement of Furfural Production from Concentrated PreHydrolysis Liquor (PHL) of a Kraft-Based Hardwood Dissolving Pulp Production Process

Hemicelluloses present in the prehydrolysis liquor (PHL) of the hardwood kraft-based dissolving pulp production process can be utilized in the production of furfural, which is an important renewable, non-petroleum-based platform chemical. A lower furfural yield was observed from the concentrated sugars in PHL in acetic-acid-catalyzed systems. The reaction rate of sugar consumption and furfural destruction in PHL was higher than those of model xylan and xylose systems, which may be due to the side-reactions of lignin with sugars and carbonization of oligomeric sugars. In order to minimize these side-reactions, a steam-stripping method of generated furfural was adopted. The results showed that the method was effective in increasing the furfural yield (41.5%) from the concentrated PHL.     

Influence of sources of dietary oils on the life span of stroke-prone spontaneously hypertensive rats

In recent studies, the life span of stroke-prone spontaneously hypertensive (SHRSP) rats was altered by a variety of dietary fats. It was relatively shorter in rats fed canola oil as the sole source of fat. The present study was performed to find out whether the fatty acid profile and the high content of sulfur compounds in canola oil could modulate the life span of SHRSP rats. SHRSP rats (47 d old, n=23/group) were matched by body weight and systolic blood pressure and fed semipurified diets containing 10% canola oil, high-palmitic canola oil, low-sulfur canola oil, soybean oil, high-oleic safflower oil, a fat blend that mimicked the fatty acid composition of canola oil, or a fat blend high in saturated fatty acids. A 1% sodium chloride solution was used as drinking water to induce hypertension. After consuming the diets for 37 d, five rats from each dietary group were killed for collection of blood and tissue samples for biochemical analysis. The 18 remaining animals from each group were used for determining their life span. The mean survival time of SHRSP rats fed canola oil (87.4±4.0 d) was not significantly different (P>0.05) from those fed low-sulfur canola oil (89.7±8.5 d), suggesting that content of sulfur in canola oil has no effect on the life span of SHRSP rats. The SHRSP rats fed the noncanola oil-based diets lived longer (mean survival time difference was 6–13 d, P<0.05) than those fed canola and low-sulfur canola oils. No marked differences in the survival times were observed among the noncanola oil-based groups. The fatty acid composition of the dietary oils and of red blood cells and liver of SHRSP rats killed after 37 d of treatment showed no relationship with the survival times. These results suggest that the fatty acid profile of vegetable oils plays no important role on the life span of SHRSP rat. However, phytosterols in the dietary oils and in liver and brain were inversely correlated with the mean survival times, indicating that the differential effects of vegetable oils might be ascribed, at least partly, to their different phytosterol contents.     

E7766, a Macrocycle-Bridged Stimulator of Interferon Genes (STING) Agonist with Potent Pan-Genotypic Activity

A strategy for creating potent and pan-genotypic stimulator of interferon genes (STING) agonists is described. Locking a bioactive U-shaped conformation of cyclic dinucleotides by introducing a transannular macrocyclic bridge between the nucleic acid bases leads to a topologically novel macrocycle-bridged STING agonist (MBSA). In addition to substantially enhanced potency, the newly designed MBSAs, exemplified by clinical candidate E7766 , exhibit broad pan-genotypic activity in all major human STING variants. E7766 is shown to have potent antitumor activity with long lasting immune memory response in a mouse liver metastatic tumor model. Two complementary stereoselective synthetic routes to E7766 are also described.     

Water-Lubricated Ni-Based Composite(Ni-Al_2O_3,Ni-SiC and Ni-ZrO_2)Thin Film Coatings for Industrial Applications

In this work,pure nickel and Ni-based nanocomposite coatings(N1-Al_2O_3,Ni-SiC and Ni-ZrO_2) were produced on steel substrate by using pulse electrodeposition technique.The industrial performance tests were conducted to evaluate the wear resistance,corrosion resistance,adhesion strength and wettability behaviour of newly developed coatings.Rolling contact ball-on-disc tribometer was used to assess anti-wear behaviour of these coatings under waterlubricated contacts.The results showed that the wear- and corrosion resistance properties of nickel alumina and Ni-SiC composite coatings significantly improved than that of pure Ni and Ni-ZrO_2 coatings.The adhesion and wettability results of Ni-Al_2O_3 composite showed better performance when compared to the rest of the coatings.The effects of incorporating nanoparticles on the surface microstructure,interface adhesion and distribution of the particles were also investigated.The coatings were characterized by using scanning electron microscopy,X-ray diffraction analysis and 3D white light interferometry.The wear failure behaviour of these coatings was further examined by post-test surface observation under optical microscope.