Uncertainty evaluation of the spectral UV irradiance evaluated by using the UVSPEC radiative transfer model

The radiative transfer models allow calculating the spectral UV irradiance from some set of measured input quantities linked with the surface reflectivity, the solar zenith angle, the ozone column and the characteristics of clouds and aerosols. The spectral irradiance yielded by a model is influenced by errors in the measurement of the input quantities. In this paper, the influences of these errors are characterized and compared with other systematic effects through an uncertainty analysis. We evaluated the uncertainty of the spectral UV irradiance rendered by the UVSPEC model, under cloudless sky conditions. In order to express the uncertainty of the output quantities (the global, direct and diffuse irradiances) in terms of the standard uncertainties of the input quantities, we used a Monte Carlo-based uncertainty propagation technique. We found that the uncertainty of the irradiance in the UV-B part of the spectrum was strongly influenced by the uncertainty attributed to the ozone column datum. Moreover, the uncertainities associated with the aerosol parameters accounted for most of the UV-A global irradiance uncertainty; the latter increased from about 4% under low aerosol conditions, up to about 14% in case of polluted air. We conclude that the UV irradiance evaluation through radiative transfer models requires paying special attention to the assessment of the aerosols properties.     

Cerium(IV) ammonium nitrate catalyzed synthesis of α-dehydro-β-amino esters

α-Dehydro-β-amino esters have been synthesized regioselectively from acetates of Baylis-Hillman adducts with amines in the presence of a catalytic amount of ceric ammonium nitrate (CAN) in good yield. The regioselectivity does not differ with respect to the polarity of the solvent.     

The signal/noise of an HMBC spectrum can depend dramatically upon the choice of acquisition and processing parameters

The effect of various acquisition and processing parameters on the sensitivity of HMBC spectra for typical organic molecules has been systematically investigated. For molecules in the 200–600 molecular weight range, an acquisition time of 0.2 to 0.4 s, a recycle time of no more than 1.0 s, optimization for ⁿJ_CH = 8 Hz and 512 time increments (with two‐ to fourfold linear prediction) are recommended. Some form of sine bell weighting along f₂ and either Gaussian or sine bell weighting along f₁ is suggested. The use of a 0.1‐s acquisition time and/or Gaussian or exponential weighting along f₂ can result in dramatic sensitivity loss, particularly for correlation peaks involving protons with complex splitting patterns, and should be avoided. Copyright © 2009 John Wiley & Sons, Ltd.     

A facile and versatile protocol for the one-pot PhI(OAc)2 mediated divergent synthesis of quinazolines from 2-aminobenzylamine

In this present work iodobenzenediacetate (PIDA) has been found to be the key reagent in absence or presence of catalytic amount of molecular iodine (I₂)/zinc chloride (ZnCl₂) to construct quinazoline scaffold from 2-aminobenzylamine and a variety of easily available aldehydes, aryl and aliphatic amines, aliphatic and aryl alcohols and nitriles. This protocol provides mild and robust conditions along with great versatility to synthesize 2-substituted quinazolines from diverse starting materials in good to excellent yields. The developed protocol is also well applicable to reactants containing ease to oxidation prone functional groups.     

Production of Cellulolytic Enzymes by Fungi Acrophialophora nainiana and Ceratocystis paradoxa Using Different Carbon Sources

Although a number of filamentous fungi, such as Trichoderma and Aspergillus, are well known as producers of cellulases, xylanases, and accessory cellulolytic enzymes, the search for new strains and new enzymes has become a priority with the increase in diversity of biomass sources. Moreover, according to the type of pretreatment applied, biomass of the same type may require different enzyme blends to be efficiently hydrolyzed. This study evaluated cellulases, xylanases, and β-glucosidases produced by two fungi, the thermotolerant Acrophialophora nainiana and Ceratocystis paradoxa. Cells were grown in submerged culture on three carbon sources: lactose, wheat bran, or steam-pretreated sugarcane bagasse, a commonly used cattle feed in Brazil. Xylanase and endo-1-4-β-glucanase (CMCase) highest production were found in A. nainiana growing on lactose and reached levels of 2,200 and 2,016 IU/L, respectively. C. paradoxa showed highest activity for xylanase when grown on wheat bran and for β-glucosidase when grown on steam-treated bagasse, at levels of 12,728 and 1,068 IU/mL, respectively.     

The 3-connected binary matroids with circumference 6 or 7

In this paper, we construct all 3-connected binary matroids with circumference equal to 6 or 7 having large rank.     

Nanocrystals,Nanorods and other Nanostructures of Nickel,Ruthenium, Rhodium and Iridium prepared by a Simple Solvothermal Procedure

The solvothermal decomposition of nickel acetate in n-octylamine medium at 250 °C gives rise to nickel nanostructures while in a hydrocarbon medium NiO nanostructures are obtained. It has been possible to obtain nickel nanorods of 12–15 nm diameter by this means. By carrying out the reaction at a slightly higher temperature, ultra-thin single-crystalline sheets of nickel are obtained. The nanorods and the thin sheets, with the FCC structure, are both ferromagnetic at room temperature, with the nanorods exhibiting high coercivities. It has been possible to obtain ruthenium, rhodium and iridium nanostructures by carrying out the decomposition of the respective metal acetylacetonates in a hydrocarbon (decalin or toluene) or an amine (n-octylamine or oleylamine) around 300 °C. Nanorod formation is favored by linear long-chain amines. The method described by us to prepare the nanostructures of nickel, ruthenium, rhodium and iridium is simple and straightforward compared to the literature procedures, the preparation of single-crystalline thin sheets of nickel by such a solution route being noteworthy. The nanostructures prepared in the amine media could be readily dispersed in hydrocarbon solvents. Dedicated to Professor Dr. Günther Schmid