Browsing Chemistry & Earth Sciences by Title
Now showing items 290-309 of 560
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l-Proline-Catalyzed Three-Component Reaction of 4-Chloro-3-formylcoumarin, Sodium Sulfide, and α-Halo Ketones: A Direct Approach to Thieno[3,2- c ]coumarins
( Georg Thieme Verlag KG , 2023 , Other)A new protocol for the synthesis of thieno[3,2-c]coumarins is disclosed. In this method, a 3-formyl-2-oxo-2H-chromene-4-thiolate anion is generated in situ by treatment of 4-chloro-3-formylcoumarin with sodium sulfide. ... -
Laser Induced Periodic Surface Structures on Nano Metal Oxide filled Polyvinylidene Fluoride Nanocomposites
( Elsevier , 2018 , Article)The ability of polarized pulsed laser in surface modification of substrate surfaces without thermally destroying them is a well-established concept of scientific procedure. In this work, we report the laser induced surface ... -
Lignin and lignocellulosic materials: A glance on the current opportunities for energy and sustainability
( Springer International Publishing , 2021 , Book chapter)Fossil fuels are running out fast. The energy demand is one of the largest challenges humankind has ever faced. Applications targeting renewable resources that are nonpetroleum based are booming. The scientific community ... -
Liquid and poly (vinyl chloride) matrix membrane electrodes for the selective determination of cocaine in illicit powders
( Elsevier , 1992 , Article)The construction of liquid membrane and PVC matrix-type cocainium ion selective electrodes and their use for direct potentiometry and potentiometric titration of cocaine are described. The ion-pair complexes of cocaine ... -
Liquid membrane electrodes for the selective determination of nicotine in cigarette smoke
( The Royal Society of Chemistry , 1989 , Article)Five liquid membrane electrode systems responsive to the nicotinium cation are described. These electrodes are based on the use of the ion-association complexes of the nicotinium cation with tetraphenylborate, 5-nitrobarbiturate, ... -
Loading Rates of Dust and Metals in Residential Houses of Arid and Dry Climatic Regions
( Taiwan Association for Aerosol Research , 2016 , Article)Dust samples were collected from 38 naturally ventilated houses for 12 weeks. Effects of three variables in two groups each were evaluated: proximity to traffic density (main- and side-roads), cigarettes smoking (smoking ... -
Low-Temperature CO Oxidation Over CuO-TiO2 Nanocatalysts
( Hamad bin Khalifa University Press (HBKU Press) , 2016 , Conference Paper)Among the diverse catalytic processes, the heterogeneous catalytic CO oxidation is an important reaction for removal of small amounts of poisoning CO in fuel cell applications and environmental remediation. Therefore, there ... -
Magnetic solid phase extraction (MSPE) for chromatographic separation of carbamates.
( Wiley , 2018 , Article)Magnetic solid phase extraction particles (MSPE) were produced using magnetite nanoparticles with diameters between 9 and 13 nm as nucleating agent. The produced particles with magnetite cores were smaller, and more irregular ... -
Major sterol composition of some algae from Qatar
( Elsevier Science Ltd. , 1995 , Article)Thirteen macroscopic algae belonging to the three main divisions Chlorophyceae, Rhodophyceae and Phaeophyceae from the coast of Qatar (Arabian Gulf) were investigated for their sterol composition by using GC-MS coupling ... -
Mangrove-bearing limestone from the Eocene Dammam Formation, Arabian Gulf: Implications for the mangrove dispersal controversy
( springer link , 2012 , Article)Fossil mangrove remains are found within the shallow carbonate strata of the Middle Eocene Dammam Formation of the Arabian Gulf. This formation is of wide distribution across most eastern parts of the Arabian Platform and ... -
Mechanism and kinetics of electrochemical degradation of uric acid using conductive-diamond anodes
( Taylor & Francis , 2016 , Article)Uric acid (UA) is one of the principal effluents of urine wastewaters, widely used in agriculture as fertilizer, which is potentially dangerous and biorefractory. Hence, the degradation of UA (2,6,8-trihydroxy purine) in ... -
Mechanistic and kinetic studies of the degradation of diethyl phthalate (DEP) by homogeneous and heterogeneous Fenton oxidation
( Elsevier B.V. , 2019 , Article)In this work, the degradation of diethyl Phthalate (DEP) by homogeneous and heterogeneous Fenton oxidation was investigated. The influence of several parameters was determined such as the initial pH, the catalyst concentration, ... -
Mechanistic study of polyepoxy succinic acid (PESA) as green corrosion inhibitor on carbon steel in aerated NaCl Solution
( Elsevier Ltd , 2021 , Article)The inhibition mechanism of mild steel corrosion in aerated aqueous 3% NaCl medium was studied using Polyepoxy succinic acid (PESA) as a green inhibitor. The study utilized electrochemical, thermodynamic, and surface ... -
Mechanochemical arylative detrifluoromethylation of trifluoromethylarenes
( Royal Society of Chemistry , 2023 , Article)The stoichiometric defluorinative functionalization of ArCF3 is a conceptually appealing research target. It enables the challenging late-stage functionalization of CF3-containing aromatic molecules and contributes to the ... -
Mechanochemical Conversion of Aromatic Amines to Aryl Trifluoromethyl Ethers
( American Chemical Society , 2022 , Article)Increased interest in the trifluoromethoxy group in organic synthesis and medicinal chemistry has induced a demand for new, selective, general, and faster methods applicable to natural products and highly functionalized ... -
Mechanochemical Defluorinative Arylation of Trifluoroacetamides: An Entry to Aromatic Amides
( American Chemical Society , 2022 , Article)The amide bond is prominent in natural and synthetic organic molecules endowed with activity in various fields. Among a wide array of amide synthetic methods, substitution on a pre-existing (O)C-N moiety is an underexplored ... -
Mechanochemical Synthesis of Orthorhombic Nickel Niobate (NiNb2O6) as a Robust and Fast Charging Anode Material for Lithium-Ion Batteries
( American Chemical Society , 2022 , Article)A generation of lithium-ion batteries that can deliver high energy and fast charging rates without compromising safety is in high demand. Despite extensive research efforts, the current Li-ion technology cannot match the ... -
Mechanochemical Transformation of CF3 Group: Synthesis of Amides and Schiff Bases
( Wiley , 2021 , Article)We communicate two mild, solvent-free mechanochemical coupling transformations of CF3 group with nitro compounds into amides or Schiff bases employing Ytterbia as a catalyst. This process proceeds via C−F bond activation, ... -
Mercurimetric potentiometric determination of barbiturates using a solid-state iodide ion-selective electrode
( Taylor and Francis Inc. , 1997 , Article)A simple potentiometric method is described for mercurimetric titration of barbiturates using a solid-state iodide ion-selective electrode. The optimum titration conditions involve the use of a borate buffer of pH 9-10 as ... -
Mercury pollution in doha (Qatar) coastal environment
( Wiley Periodicals, Inc. , 1994 , Article)Surface water and sediment samples were collected from the Doha coastal area and analyzed for content of physico-chemical forms of mercury. Dissolved reactive Hg (2.9 ng L?1) represented 81.0% of the total dissolved Hg ...