تصفح Chemistry & Earth Sciences حسب العنوان
السجلات المعروضة 344 -- 363 من 545
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Optical biosensor based on ultrathin SOI waveguides
( Optica Publishing Group (formerly OSA) , 2020 , Conference Paper)We introduce an optical biosensor utilizing the MMI configuration and based on the ultrathin SOI platform. The biosensor was optimized using finite difference time domain simulations. A sensitivity of 420 nm/RIU was achieved. -
Optical modulator based on silicon nanowires racetrack resonator
( SPIE , 2018 , Conference Paper)An optical modulator based on the racetrack resonator configuration is introduced.The structure of the resonator modulator is built from silicon nanowires on silica.The cladding and voids between the silicon nanowires are ... -
Optimization Of The Electronic And Optical Properties Of Tio2 For Clean Fuel Production
( Hamad bin Khalifa University Press (HBKU Press) , 2014 , Conference Paper)Among different crystal structures and morphologies of TiO2, vertically oriented anatase nanotube arrays show the highest activity for solar energy conversion. However, the long-standing bottleneck is the fact that TiO2 ... -
Organoboronic acids/esters as effective drug and prodrug candidates in cancer treatments: challenge and hope
( Taylor and Francis Ltd. , 2023 , Article Review)Boronic acids/esters have recently emerged in the field of medicinal and pharmaceutical research due to their exceptional oxophilicity, low toxicity, and unique structure. They are known as potent enzyme inhibitors, cancer ... -
Oxidative degradation of tannic acid in aqueous solution by UV/S2O8 2- and UV/H2O2/Fe2+ processes: A comparative study
( MDPI AG , 2019 , Article)Tannic acid (TA) is a major pollutant present in the wastewater generated from vegetable tanneries process and food processing. This work studied TA degradation by two advanced oxidation processes (APOs): UV irradiation ... -
(−)-Paniculatol, a new ent-labdane bromoditerpene from Laurencia paniculata
( Elsevier Science Ltd. , 1997 , Article)(−)-Paniculatol, 1, an unusual tricyclic bromoditerpene belonging to the ent-labdane series has been identified in the red alga Laurencia paniculata collected on Qatari coasts, Arabian Gulf. The structure displays an unusual ... -
Performance and computational studies of two soluble pyran derivatives as corrosion inhibitors for mild steel in HCl
( Elsevier B.V. , 2019 , Article)The present study is aiming to explore the effect of 4-Hydroxy-6-methyl-3-(3-quinolin-8-yl-acryloyl)-pyran-2-one (HMQP) and 3-[3-(4-Dimethylamino-phenyl)-acryloyl]-4-hydroxy-6-methyl-pyran-2-one (DMPHP) on mild steel (MS) ... -
Performance of Pristine versus Magnetized Orange Peels Biochar Adapted to Adsorptive Removal of Daunorubicin: Eco-Structuring, Kinetics and Equilibrium Studies
( Multidisciplinary Digital Publishing Institute (MDPI) , 2023 , Article)Drugs and pharmaceuticals are an emergent class of aquatic contaminants. The existence of these pollutants in aquatic bodies is currently raising escalating concerns because of their negative impact on the ecosystem. This ... -
Phospholipid fatty acid composition of nine marine sponges from Qatar
( IFREMER , 1998 , Conference Paper)Phospholipid fatty acid composition was studied in sponge from Qatar including eight Demospongia and one Calcarea. More than 60 fatty acids were identified in each species as methyl esters and N-acyl pyrrolidides by gas ... -
Phospholipid Fatty Acids Compositions of Sponges from Qatar I- Haplosclerida
( Qatar University , 2006 , Article)The phospholipid fatty acid contents of six Haplosclerida sponges collected along Qatari ;ts, Arabian Gulf, were identified by coupling GC-MS experiments. More than hundred of rated and unsaturated fatty acids have been ... -
Phosphonated Polyetheramine-Coated Superparamagnetic Iron Oxide Nanoparticles for Inhibition of Oilfield Scale
( American Chemical Society , 2023 , Article)Oilfield scale is one of the significant problems in hydrocarbon production in the oil and gas industry. Many research groups have attempted to develop greener chemicals to meet environmental regulations. Magnetic nanoparticles ... -
Photocatalytic degradation of methyl orange as a model compound
( Elsevier , 2002 , Article)Titanium dioxide (TiO2) was used as a photocatalyst for the detoxification of water containing methyl orange (MO), which was used as a model compound. Solar radiation was used as an irradiation source. It was found that ... -
Photodynamic therapy for hair removal
( Hamad bin Khalifa University Press (HBKU Press) , 2013 , Article)Background: Unwanted hair is one of the most common medical problems affecting women of reproductive age inducing a lot of psychological stress and threatening their femininity and self-esteem. Old methods of removing ... -
Photoelectrocatalytic hydrogen production on ternary Co-Pi/Ag/TiON nanotube array photocatalysts
( John Wiley and Sons Ltd , 2021 , Article)Ternary Co-Pi-Ag/TiON photocatalysts were designed and fabricated by a facile precipitation and electrochemical strategy. The results showed the superiority of the Co-Pi-Ag/TiON as a promising photoanode for photoelectrochemical ... -
Photoinduced electron transfer interaction of anthraquinones with aniline quenchers: Influence of methyl substitution in aniline donors
( Elsevier , 2017 , Article)© 2016 Elsevier B.V. Photoinduced electron transfer between triplet state of 9,10-anthraquinone (AQ) and its two derivatives: 2-chloro-9,10-anthraquinone (CAQ) and sodium anthraquinone-2-sulfonate (AQS) and ground state ... -
Physical functionalization of multi-walled carbon nanotubes for enhanced dispersibility in aqueous medium
( Springer Nature , 2020 , Article)Noncovalent functionalization of multi-walled carbon nanotubes (MWCNTs) by anionic surfactants (sodium dodecylbenzene sulfonate; SDBS and sodium cholate; SC) results in stable aqueous dispersions. SDBS showed better ... -
Physicochemical Properties of Derivatives of N,N-Dimethylamino–cyclic–chalcones: Experimental and Theoretical Study
( Wiley-Blackwell , 2016 , Article)A series of three N,N-dimethyl-amino-cyclic-chalcones chromophores of the D-π-A type (1-3) where, (Donor= N,N-dimethyl-aniline) and Acceptor= indan-1-one (1), 3,4-dihydro-2H-naphthalen-1-one (2) and 3,4,5-tetrahydro-benz ... -
Phytochemical Analysis of Acacia ehrenbergiana (Hayne) Grown in Qatar: Identification of Active Ingredients and Their Biological Activities
( MDPI , 2022 , Article)Acacia ehrenbergiana (Hayne), also known as Salam, is a highly drought resistant shrub distributed in North and East Africa, and the Arabian Peninsula. The plant is gathered for its gum and fiber, and is an important legume ... -
Phytochemical Analysis of Anastatica hierochuntica and Aerva javanica Grown in Qatar: Their Biological Activities and Identification of Some Active Ingredients
( MDPI , 2023 , Article)Plant-derived compounds and their extracts are known to exhibit chemo preventive (antimicrobial, antioxidant and other) activities. The levels of such chemo preventive compounds vary depending on environmental factors, ... -
Piezoelectric properties of zinc oxide/iron oxide filled polyvinylidene fluoride nanocomposite fibers
( Springer , 2021 , Article)Piezoelectric nanogenerators (PENG) with flexible and simple design have pronounced significance in fabricating sustainable devices for self-powering electronics. This study demonstrates the fabrication of electrospun ...