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451.
Md. Ahsan Habib Iqbal Mohmmad Ibrahim Ismail Abu Jafar Mahmood Md. Rafique Ullah 《Journal of Saudi Chemical Society》2012,16(4):423-429
Photocatalytic decolorization of BGY, an anionic dye, has been investigated in TiO2 and ZnO aqueous dispersions under UV-light irradiation. Spectrum of the dye has been found unaffected in the pH range 4.21–11.30. Adsorption is a prerequisite for the metal oxide-mediated photodegradation/photodecolorization and the extent of decolorization has been discussed in terms of the Langmuir–Hinshelwood model. Complete decolorization was achieved in case of UV irradiation whereas degradation of BGY was found to be about ca.75%. ZnO-mediated decolorization has appeared to be better and faster. The effects of various parameters, such as catalyst loading, pH and initial concentration of the dye on decolorization have been investigated. 相似文献
452.
The single-wing extension of the bowl-shaped tribenzotriquinacene (TBTQ) framework with polycondensed aromatic hydrocarbon units has been reported. In the course of a Scholl reaction, one of the three-dimensional bays of the TBTQ core has been bridged by a PAH unit to generate a seven-membered ring within the merged TBTQ-(hexa-peri-hexabenzocoronene) scaffold. 相似文献
453.
Tanveer Hussain Bokhari A. Mushtaq Islam Ullah Khan 《Journal of Radioanalytical and Nuclear Chemistry》2010,284(2):265-271
Production of radioactive scandium by irradiating natural titanium metal in Pakistan Research Reactor-1 was evaluated. The
production rate of 47Sc and other radioactive scandium was estimated. High specific activity 47Sc can be produced by irradiating enriched 47Ti in sufficient quantities needed for therapeutic applications. A new separation technique based on column chromatography
was developed. Neutron irradiated titanium was dissolved in hydrofluoric acid, which was evaporated and taken in distilled
water. The resulting solution was loaded on silica gel column. The radioactive scandium comes out first and the inactive titanium
is removed with 2 M HCl. More than 95% radioactive scandium was recovered, while chemical impurity of titanium determined
by optical emission spectroscopy was less than 0.01 μg/mL in final product. 相似文献
454.
455.
Irfan Ullah Musa Kaleem Baloch Gulrez Fatima Durrani 《Journal of solution chemistry》2012,41(2):215-222
The solubility of an anesthetic drug, LIDOCAINE, in water was investigated in the presence of ionic, nonionic and zwitterionic
surfactants at 25 °C, and the solubility was found to increase linearly with the surfactant concentration. The molar solubilization
ratio, R
m,s, and Gibbs free energy, DGso\Delta G_{\mathrm{s}}^{\mathrm{o}} values for nonionic surfactants fall in the order DDAO > Brij 35 > Brij 30, whereas for ionic and zwitterionic surfactants
the order is DDAPS > DTAB > SDS. The high negative values of the Gibbs energies in the cases of DDAO and DDAPS prove them
to be better surfactants for solubilizing this drug as compared to the other surfactants. 相似文献
456.
Hussain J Begum N Hussain H Khan FU Rehman NU Al-Harrasi A Ali L 《Natural product communications》2012,7(5):615-616
Phytochemical investigation of Ajuga bracteosa Wall ex Benth. (Labiatae) resulted in the isolation of a new phenolic compound, ajuganane (1) and three known compounds, 3,4'-dihydroxy-3,6,7-trimethoxyflavone, 7-hydroxy-3,6,3',4'-tetramethoxyflavone and ursolic acid. The structure of the new compound was elucidated by detailed spectroscopic (1H, 13C NMR, COSY, HMQC, HMBC), and HR-EI-MS analysis. 相似文献
457.
Faheem Ullah Abbas Khan Hazizan Md Akil 《Journal of Dispersion Science and Technology》2013,34(12):1777-1785
Recent development in dispersion science and technology demands block copolymers with a variable block length and composition. To highlight that purpose, the surface active, associative, colloidal, and thermodynamic behavior of three diblock copolymers having different hydrophilic to hydrophobic ratio is reported here. Using surface tension and light scattering measurements, the micellization and adsorption behavior of polyoxyethylene and polyoxybutylene diblock copolymers of the type EmBn have been analyzed. Critical micelle concentration (CMC) and related thermodynamic parameters like free energy (ΔGmic), enthalpy (ΔHmic), and entropy (ΔSmic) of micellization were calculated from CMC value using the closed association model. Likewise, the surface active parameters, like surface excess concentration (Γ2), area per molecule (A2), and thermodynamic parameters such as free energy (ΔGads), enthalpy (ΔHads), and entropy (ΔSads) of adsorption of polymer at the air/water interface, were also calculated at various temperatures. Static and dynamic light scattering techniques were employed for the determination of the weight-average molar (Mw), association number (Nw), polymer–water interaction (A2), and micellar size in terms of hydrodynamic radii (Rh) of copolymer micelles. The effect of block length and solution temperature on the surface and micellar properties of these copolymers was also investigated. 相似文献
458.
The hydrogen adsorption (storage) studies upon Ni/A1203 nano-composite prepared by metal organic chemical vapor deposition technique (MOCVD) exploiting single source molec ular precursor (SSP) approach were carried out. The Ni/A1203 nano-composite is prepared in cold walled MOCVD reactor by the decomposition of SSP, [H2AI(OtBu)]2, on a substrate holding Ni(acac)2 powder. The SSP is a reducing agent which reduces Ni+2 to Ni0 and works as source for Al203 matrix in which the Ni0 is dispersed. The resulting Ni/A1203 nano-composite is characterized by XRD, SEM, TEM, and EDX. The hydrogen adsorption (storage) studies are performed using home-made Sievert's type apparatus. The hydrogen storage studies reveal that approximately 2.9% (mass ratio) hydrogen can be stored in the Ni/A1203 nano-composite. The results show that Ni/A1203 nano-composite can be a po- tential candidate for hydrogen storage which can be used for onboard fuel purposes. 相似文献
459.
PARK ChongYeon GHOSH Trisha MENG ZeDa KEFAYAT Ullah VIKRAM Nikam OH WonChun 《催化学报》2013,34(4):711-717
CuS-graphene oxide/TiO2 composites were prepared using a sol-gel method to improve the photocatalytic performance of the photocatalyst. The composites were characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray analysis, and transmission electron microscopy. The photocatalytic activities were examined by the degradation of methylene blue (MB) under visible-light irradiation. The photodegradation of MB under visible-light irradiation reached 90.1% after 120 min. The kinetics of MB degradation was plotted alongside the values calculated from the Langmuir-Hinshelwood equation. The CuS-graphene oxide/TiO2 sample prepared using 0.2 mol of TiO2 showed the best photocatalytic activity. This was attributed to a cooperative reaction as a result of increased photoabsorption by graphene oxide and an increased photocatalytic effect by CuS. 相似文献
460.
Syed Raza Shah Zarbad Shah Najeeb Ullah Javid Hussain Rashid Al-Harrasi Ajmal Khan Jeremy M. Rawson Ahmed Al-Harrasi Muhammad U. Anwar 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(3):294-303
Reactions of 1,10‐phenanthroline (phen) and 2‐(3,4‐dichlorophenyl)acetic acid (dcaH) with Mn(CO3) (M = LiI, NaI and MgII; n = 1 and 2) in MeOH yield the mononuclear lithium complex aqua[2‐(3,4‐dichlorophenyl)acetato‐κO](1,10‐phenanthroline‐κ2N,N′)lithium(I), [Li(C8H5Cl2O2)(C12H8N2)(H2O)] or [Li(dca)(phen)(H2O)] ( 1 ), the dinuclear sodium complex di‐μ‐aqua‐bis{[2‐(3,4‐dichlorophenyl)acetato‐κO](1,10‐phenanthroline‐κ2N,N′)sodium(I)}, [Na2(C8H5Cl2O2)2(C12H8N2)2(H2O)2] or [Na2(dca)2(phen)2(H2O)2] ( 2 ), and the one‐dimensional chain magnesium complex catena‐poly[[[diaqua(1,10‐phenanthroline‐κ2N,N′)magnesium]‐μ‐2‐(3,4‐dichlorophenyl)acetato‐κ2O:O′] 2‐(3,4‐dichlorophenyl)acetate monohydrate], {[Mg(C8H5Cl2O2)(C12H8N2)(H2O)2](C8H5Cl2O2)·H2O}n or {[Mg(dca)(phen)(H2O)2](dca)·H2O}n ( 3 ). In these complexes, phen binds via an N,N′‐chelate pocket, while the deprotonated dca? ligands coordinate either in a monodentate (in 1 and 2 ) or bidentate (in 3 ) fashion. The remaining coordination sites around the metal ions are occupied by water molecules in all three complexes. Complex 1 crystallizes in the triclinic space group P with one molecule in the asymmetric unit. The Li+ ion adopts a four‐coordinated distorted seesaw geometry comprising an [N2O2] donor set. Complex 2 crystallizes in the triclinic space group P with half a molecule in the asymmetric unit, in which the Na+ ion adopts a five‐coordinated distorted spherical square‐pyramidal geometry, with an [N2O3] donor set. Complex 3 crystallizes in the orthorhombic space group P212121, with one Mg2+ ion, one phen ligand, two dca? ligands and three water molecules in the asymmetric unit. Both dcaH ligands are deprotonated, however, one dca? anion is not coordinated, whereas the second dca? anion coordinates in a bidentate fashion bridging two Mg2+ ions, resulting in a one‐dimensional chain structure for 3 . The Mg2+ ion adopts a distorted octahedral geometry, with an [N2O4] donor set. Complexes 1 – 3 were evaluated against urease and α‐glucosidase enzymes for their inhibition potential and were found to be inactive. 相似文献