The carboxylative cyclization of o-hydroxy- and o-acetamidoacetophenone with carbon dioxide promoted by the organic base 1,8-diazabicycloundec-7-ene (DBU) is reported. This reaction provides convenient access to the biologically important compounds 4-hydroxy-2H-chromen-2-one and 4-hydroxy-2(1H)-quinolinone in moderate to good yields using carbon dioxide as the carboxylation reagent. An acyl mig...

A novel heat-sealing performance is achieved by polyethylene (PE) nanocomposites reinforced by ethylene vinyl acetate (EVA) and montmorillonite (MMT). Appropriate nanocomposite design leads to hermetic seals with a general peelable/easy-open character across the broadest possible sealing temperature range. Observations of the fracture seal surfaces by infrared spectroscopy and electron microsco...

 All electricity generation technologies emit greenhouse gases at some point in their life cycle and hence have a carbon footprint.  Fossil-fuelled generation has a high carbon footprint, with most emissions produced during plant operation. “Carbon capture and storage” could reduce these significantly, though this is unproven at full scale.  Nuclear and renewable generation generally have a ...

Sources and sinks of carbon associated with forests depend strongly on the management regime and spatial patterns in potential productivity. Satellite remote sensing can provide spatially explicit information on land cover, standage class, and harvesting. Carbon-cycle process models coupled to regional climate databases can provide information on potential rates of production and related rates ...

Alkenylboranes R-CH=CH-B(C6F5)2 undergo carbon-carbon coupling by means of 1,1-alkenylboration with diarylphosphino-enynes to give substituted conjugated hexatriene derivatives that bear a vicinal pair of B(C6F5)2 Lewis acid and PAr2 Lewis base functionalities at their central carbon portions. A series of six examples was prepared and all compounds were characterized by X-ray diffraction. Conse...

The Henderson-Hasselbalch equation and the base excess have been used traditionally to describe the acid-base balance of the blood. In 1981, Stewart proposed a new model of acid-base balance based upon three variables, the "strong ion difference" (SID), the total weak acids (ATot), and the partial pressure of carbon dioxide (Pco2). Over 20 years later, Stewart's physiochemical model still remai...

BACKGROUND To examine the potential improvement in treatment planning for patients with skull base meningioma using IMRT compared to carbon ion or proton beams with and without a gantry. METHODS Five patients originally treated with photon IMRT were selected for the study. Ion beams were chosen using a horizontal beam or an ion gantry. Intensity controlled raster scanning and the intensity mo...

The preparation of nanofluids is very important to their thermophysical properties. Nanofluids with the same nanoparticles and base fluids can behave differently due to different nanofluid preparation methods. The agglomerate sizes in nanofluids can significantly impact the thermal conductivity and viscosity of nanofluids and lead to a different heat transfer performance. Ultrasonication is a c...

abstract porous materials are commonly found in nature and as industrial materials such as wood, carbon, foams, ceramics and bricks. in order to use them effectively, their mechanical properties must be understood in relation to their micro-structures. foam made from non-flammable metal will remain non-flammable and the foam is generally recyclable back to its base material. this research work ...

One of the most critical quality attributes of orodispersible films (ODFs) is related to the development of dosage forms with tensile properties suitable for the packaging and patient's handling. Aiming to develop a strategy to reinforce the tensile properties, the current work reported the feasibility to improve the tensile strength of maltodextrins (MDX) based ODFs by adding an amorphous wate...