Sign In

 2015 CENT Affiliated Published Papers


​97"Weatherability of conventional and nanocomposites of LDPE and Zinc Oxide", Redhwi HH, Siddiqui MN, Andrady AL, Muhammad Y, Syed H, Polymer Composites, 2017 (38) 341-8.
96"Evaluation of mechanical and thermal properties of microwave irradiated poly (styrene-co-methyl methacrylate)/graphene nanocomposites", Zubair M, Jose J, Al-Harthi MA, Composite Interfaces, 2015 (22) 595-610.
95"Synthesis, characterization and reaction kinetics of PMMA/silver nanocomposites prepared via in situ radical polymerization", Siddiqui MN, Redhwi HH, Vakalopoulou E, Tsagkalias I, Ioannidou MD, Achilias DS, European Polymer Journal, 2015 (72) 256-69.
94"Preparation and properties of polypropylene-asphaltene composites", Siddiqui MN, Polymer Composites, 2015.
93"Studies of Different Properties of Polystyrene‐Asphaltene Composites", Siddiqui MN, Macromolecular Symposia, 2015 (354) 184-90.
92"Visible-light-induced photodegradation enhancement of methyl orange over bismuth oxybromide through a semiconductor mediated process", Shi H, Gondal MA, Al-Saadi AA, Chang X, Journal of Advanced Oxidation Technologies, 2015 (18) 78-84.
91"The Efficient Photocatalytic Degradation of Methyl Tert-butyl Ether Under Pd/ZnO and Visible Light Irradiation", Seddigi ZS, Ahmed SA, Bumajdad A, Danish EY, Shawky AM, Gondal MA, et al., Photochemistry and Photobiology, 2015 (91) 265-71.
90"Role of crystal growth modifiers in the synthesis of ZSM-12 zeolite", Sanhoob MA, Muraza O, Al-Mutairi EM, Ullah N, Advanced Powder Technology, 2015 (26) 188-92.
89"Characterization of mechanically milled and spark plasma sintered Al2124-CNT nanocomposites", Saheb N, Science of Sintering, 2015 (47) 119-29.
88"Hierarchical ZnO/zeolite nanostructures: synthesis, growth mechanism and hydrogen detection", Qurashi A, Alhaffar M, Yamani ZH, RSC Adv, 2015 (5) 22570-7.
87"Facile catalyst-free straightforward thermal evaporation of ultra-long antimony oxide microwires: Synthesis and characterization", Qurashi A, Superlattices and Microstructures, 2015 (81) 161-6.
86"Highly Efficient and Selective Oxidation of Aromatic Alcohols Photocatalyzed by Nanoporous Hierarchical Pt/Bi2WO6 in Organic Solvent-Free Environment", Qamar M, Elsayed RB, Alhooshani KR, Ahmed MI, Bahnemann DW, ACS applied materials & interfaces, 2015 (7) 1257-69.
85"Chemoselective and highly efficient conversion of aromatic alcohols into aldehydes photo-catalyzed by Ag3PO4 in aqueous suspension under simulated sunlight", Qamar M, Elsayed RB, Alhooshani KR, Ahmed MI, Bahnemann DW, Catalysis Communications, 2015 (58) 34-9.
84"Enhanced photoelectrochemical and photocatalytic activity of WO3-surface modified TiO2 thin film", Qamar M, Drmosh Q, Ahmed MI, Qamaruddin M, Yamani ZH, Nanoscale Research Letters, 2015 (10) 54.
83"Amelioration in the visible-light-driven photocatalysis by <002> faceted WO3 nanocuboids", Qamar M, Alhooshani K, Ahmed MI, Azad AM, Merzougui B, Catalysis Communications, 2015 (70) 21-5.
82"Single-Pot Synthesis of 001-Faceted N-Doped Nb2O5/Reduced Graphene Oxide Nanocomposite for Efficient Photoelectrochemical Water Splitting", Qamar M, Abdalwadoud M, Ahmed MI, Azad AM, Merzougui B, Bukola S, et al., ACS Appl Mater Interfaces, 2015 (7) 17954-62.
81"Estimation of surface tension of methyl esters biodiesels using computational intelligence technique", Owolabi TO, Gondal MA, Applied Soft Computing, 2015 (37) 227-33.
80"Synthesis, characterization and anticancer activity of gold(III) complexes with (1R,2R)-(−)-1,2-diaminocyclohexane", Omer KH, Seliman AA, Altaf M, Casagrande N, Aldinucci D, Altuwaijri S, et al., Polyhedron, 2015 (102) 773-81.
79"Fiber-Embedded Metallic Materials: From Sensing towards Nervous Behavior", Saheb N, Mekid S, Materials, 2015 (8) 7938-61.
78"Effect of Processing on Mechanically Alloyed and Spark Plasma Sintered Al-Al2O3Nanocomposites", Saheb N, Shahzeb Khan M, Hakeem AS, Journal of Nanomaterials, 2015 (2015) 1-13.
77"Tetrakis(thione)platinum(II) complexes: synthesis, spectroscopic characterization, crystal structures, andin vitrocytotoxicity", Mustafa AZA, Monim-ul-Mehboob M, Jomaa MY, Altaf M, Fettouhi M, Isab AA, et al., Journal of Coordination Chemistry, 2015 (68) 3511-24.
76"Aquathermolysis of heavy oil: A review and perspective on catalyst development", Muraza O, Galadima A, Fuel, 2015 (157) 219-31.
75"A review on coke management during dry reforming of methane", Muraza O, Galadima A, International Journal of Energy Research, 2015 (39) 1196-216.
74"Microwave-assisted hydrothermal synthesis of submicron ZSM-22 zeolites and their applications in light olefin production", Muraza O, Abdul-lateef A, Tago T, Nandiyanto ABD, Konno H, Nakasaka Y, et al., Microporous and Mesoporous Materials, 2015 (206) 136-43.
73"Hydrous pyrolysis of heavy oil using solid acid minerals for viscosity reduction", Muraza O, Journal of Analytical and Applied Pyrolysis, 2015 (114) 1-10.
72"Maximizing Diesel Production through Oligomerization: A Landmark Opportunity for Zeolite Research", Muraza O, Industrial & Engineering Chemistry Research, 2015 (54) 781-9.
71"Flow-assisted automated solid-phase microextraction for the determination of chloroethers in aqueous matrices", Mousa A, Basheer C, Abdulnaser A, Alhooshani K, Al-Arfaj A, International Journal of Environmental Analytical Chemistry, 2015 (95) 744-53.
70"Development of an improved ligand mimetic calibration system for the analysis of iron(III) in seawater using the iron(III) chalcogenide glass ion selective electrode: A combined mechanistic and analytical study", Maric M, Sohail M, Veder J-P, De Marco R, Sensors and Actuators B: Chemical, 2015 (207) 907-17.
69"A fluorescent chemosensor for sequential recognition of gallium and hydrogen sulfate ions based on a new phenylthiazole derivative", Kim B-Y, Kim H-S, Helal A, Sensors and Actuators B: Chemical, 2015 (206) 430-4.
68"A facile fabrication of platinum nanoparticle-modified graphite pencil electrode for highly sensitive detection of hydrogen peroxide", Kawde A-N, Aziz M, Baig N, Temerk Y, Journal of Electroanalytical Chemistry, 2015 (740) 68-74.
67"Compatibilizing role of carbon nanotubes in poly(vinyl alcohol)/starch blend", Jose J, De SK, AlMa'adeed MA-A, Dakua JB, Sreekumar PA, Sougrat R, et al., Starch - Stärke, 2015 (67) 147-53.
66"Effect of graphene loading on thermomechanical properties of poly(vinyl alcohol)/starch blend", Jose J, Al-Harthi MA, AlMa'adeed MA, Dakua JB, De SK, Journal of Applied Polymer Science, 2015 (132) n/a-n/a.
65"Schiff Base Ligand Coated Gold Nanoparticles for the Chemical Sensing of Fe(III) Ions", Jimoh AA, Helal A, Shaikh MN, Abdul Aziz M, Yamani ZH, Al-Ahmed A, et al., Journal of Nanomaterials, 2015 (2015) 1-7.
64"The role of alcohols and diols as co-solvents in fabrication of TON zeolite", Jamil AK, Muraza O, Al-Amer AM, Journal of Industrial and Engineering Chemistry, 2015 (29) 112–9.
63"Synthesis, crystal structure and electrochemical and DNA binding studies of oxygen bridged-copper(II) carboxylate", Iqbal M, Ali S, Tahir MN, Muhammad N, Shah NA, Sohail M, et al., Journal of Molecular Structure, 2015 (1093) 135-43.
62"Synthesis of Nitrogen-Doped Carbon Nanotubes Using Injection-Vertical Chemical Vapor Deposition: Effects of Synthesis Parameters on the Nitrogen Content", Hachimi A, Merzougui B, Hakeem A, Laoui T, Swain GM, Chang Q, et al., Journal of Nanomaterials, 2015 (2015) 1-9.
61"Photo-catalytic deactivation of sulfate reducing bacteria – a comparative study with different catalysts and the preeminence of Pd-loaded WO3nanoparticles", Gondal MA, Dastageer MA, Khalil AB, Rashid SG, Baig U, RSC Adv, 2015 (5) 51399-406.
60"Synthesis, characterization and visible light photocatalytic activity of Cr3+, Ce3+and N co-doped TiO2for the degradation of humic acid", Rashid SG, Gondal MA, Hameed A, Aslam M, Dastageer MA, Yamani ZH, et al., RSC Adv, 2015 (5) 32323-32.
59"Hydroisomerization of sustainable feedstock in biomass-to-fuel conversion: a critical review", Galadima A, Muraza O, International Journal of Energy Research, 2015 (39) 741-59.
58"Zeolite catalysts in upgrading of bioethanol to fuels range hydrocarbons: A review", Galadima A, Muraza O, Journal of Industrial and Engineering Chemistry, 2015 (31) 1-14.
57"Role of zeolite catalysts for benzene removal from gasoline via alkylation: A review", Galadima A, Muraza O, Microporous and Mesoporous Materials, 2015 (213) 169-80.
56"Waste to liquid fuels: potency, progress and challenges", Galadima A, Muraza O, International Journal of Energy Research, 2015 (39) 1451-78.
55"From synthesis gas production to methanol synthesis and potential upgrade to gasoline range hydrocarbons: A review", Galadima A, Muraza O, Journal of Natural Gas Science and Engineering, 2015 (25) 303-16.
54"Catalytic Upgrading of Bioethanol to Fuel Grade Biobutanol: A Review", Galadima A, Muraza O, Industrial & Engineering Chemistry Research, 2015 (54) 7181-94.
53"In situ fast pyrolysis of biomass with zeolite catalysts for bioaromatics/gasoline production: A review", Galadima A, Muraza O, Energy Conversion and Management, 2015 (105) 338-54.
52"Recent Developments on Silicoaluminates and Silicoaluminophosphates in the Methanol-to-Propylene Reaction: A Mini Review", Galadima A, Muraza O, Industrial & Engineering Chemistry Research, 2015 (54) 4891-905.
51"Catalytic upgrading of vegetable oils into jet fuels range hydrocarbons using heterogeneous catalysts: A review", Galadima A, Muraza O, Journal of Industrial and Engineering Chemistry, 2015 (29) 12-23.
50"Enhanced oxidative desulfurization in a film-shear reactor", Fox BR, Brinich BL, Male JL, Hubbard RL, Siddiqui MN, Saleh TA, et al., Fuel, 2015 (156) 142-7.
49"Synthesis, crystal structure, theoretical calculations, and electrochemical and biological studies of polymeric (N,N,N′,N′-tetramethylethylenediamine)bis(thiocyanato-κN)copper(II), [Cu(tmeda)(NCS)2]n", Espinosa A, Sohail M, Habib M, Naveed K, Saleem M, Rehman H-u, et al., Polyhedron, 2015 (90) 252-7.
48"Microwave assisted growth of SAPO-34 on β-SiC foams for methanol dehydration to dimethyl ether", Elamin MM, Muraza O, Malaibari Z, Ba H, Nhut J-M, Pham-Huu C, Chemical Engineering Journal, 2015 (274) 113-22.
47"Fabrication of CuO-1.5ZrO2 composite thin film, from heteronuclear molecular complex and its electrocatalytic activity towards methanol oxidation", Ehsan MA, Hakeem AS, Khaledi H, Mazhar M, Shahid MM, Pandikumar A, et al., RSC Advances, 2015 (5) 103852-62.
46"Evolution of ppm amount of Ru(III) complexes for effective living radical polymerization of MMA", Chen X, Nguyen TTD, Khan MY, Xia L, He D, Lee SW, et al., Journal of Polymer Science Part A: Polymer Chemistry, 2015 (53) 1961-5.
45"Constrained growth of ultrasmall BiOCl nanodiscs with a low percentage of exposed {001} facets and their enhanced photoreactivity under visible light irradiation", Chang X, Wang S, Qi Q, Gondal MA, Rashid SG, Yang D, et al., Applied Catalysis B: Environmental, 2015 (176-177) 201-11.
44"Insights into the growth of bismuth nanoparticles on 2D structured BiOCl photocatalysts: an in situ TEM investigation", Chang X, Wang S, Qi Q, Gondal MA, Rashid SG, Gao S, et al., Dalton Trans, 2015 (44) 15888-96.
43"Compatibility of poly(acrylic acid)/starch blends", Bin-Dahman OA, Jose J, Al-Harthi MA, Starch - Stärke, 2015 (67) 1061-9.
42"Gd-Complexes of New Arylpiperazinyl Conjugates of DTPA-Bis (amides): Synthesis, Characterization and Magnetic Relaxation Properties", Ba-Salem AO, Ullah N, Shaikh MN, Faiz M, Ul-Haq Z, Molecules, 2015 (20) 7807-19.
41"Synthesis and magnetic relaxation properties of new Gd(III) complexes derived from DTPA-bis(amide) conjugates of arylpiperazinyl amines", Ba-Salem AO, Shaikh MN, Ullah N, Faiz M, Inorganic Chemistry Communications, 2015 (56) 5-7.
40"Synthesis and properties of polyethylene/TiO2nanocomposites using a vanadium catalyst", Bakather OY, Al-harthi MA, The Canadian Journal of Chemical Engineering, 2015 (93) 2184-9.
39"Steam-assisted catalytic cracking of n-hexane over La-Modified MTT zeolite for selective propylene production", Bakare IA, Muraza O, Taniguchi T, Tago T, Nasser G, Yamani ZH, et al., Journal of Analytical and Applied Pyrolysis, 2015 (116) 272-80.
38"The effect of non-ionic surfactant in the microwave-assisted synthesis of MTT zeolite optimized by Taguchi method", Bakare IA, Muraza O, Al-Amer AM, Yamani ZH, Journal of the Taiwan Institute of Chemical Engineers, 2015 (50) 314-21.
37"Fluidized bed ODH of ethane to ethylene over VOx–MoOx/γ-Al2O3 catalyst: Desorption kinetics and catalytic activity", Bakare IA, Mohamed SA, Al-Ghamdi S, Razzak SA, Hossain MM, de Lasa HI, Chemical Engineering Journal, 2015 (278) 207-16.
36"Enzyme immobilization and molecular modeling studies on an organic–inorganic polypyrrole–titanium(iv)phosphate nanocomposite", Baig U, Gondal MA, Alam MF, Laskar AA, Alam M, Younus H, New J Chem, 2015 (39) 6976-86.
35"In-situ aging microwave heating synthesis of LTA zeolite layer on mesoporous TiO2 coated porous alumina support", Baig MA, Patel F, Alhooshani K, Muraza O, Wang EN, Laoui T, Journal of Crystal Growth, 2015 (432) 123-8.
34"Size-controlled preparation of fluorescent gold nanoparticles using pamoic acid", Aziz MA, Kim J-P, Shaikh MN, Oyama M, Bakare FO, Yamani ZH, Gold Bull, 2015 (48) 85-92.
33"Electrochemical Investigation of Metal Oxide Conducting Electrodes for Direct Detection of Sulfide", Aziz MA, Sohail M, Oyama M, Mahfoz W, Electroanalysis, 2015 (27) 1268-75.
32"Room-temperature synthesis of TiO2 nanospheres and their solar driven photoelectrochemical hydrogen production", Avasare V, Zhang Z, Avasare D, Khan I, Qurashi A, International Journal of Energy Research, 2015 (39) 1714-9.
31"Structural and optical properties of hydrothermally synthesized mesoporous Si/TiO2 nanowire composites", Asiah MN, Mamat MH, Khusaimi Z, Abdullah S, Rusop M, Qurashi A, Microelectronic Engineering, 2015 (136) 31-5.
30"Surfactant-free seed-mediated large-scale synthesis of mesoporous TiO2 nanowires", Asiah MN, Mamat MH, Khusaimi Z, Abdullah S, Rusop M, Qurashi A, Ceramics International, 2015 (41) 4260-6.
29"Characterization of Ball Milled Ni–Al2O3 Nanocomposite Powders", Arif TM, Saheb N, Powder Metallurgy and Metal Ceramics, 2015 (53) 541-8.
28"Membrane Assisted Simultaneous Extraction and Derivatization with Triphenylphosphine of Elemental Sulfur in Arabian Crude Samples by Gas Chromatography/Mass Spectrometry", Al-Zahrani I, Aneel Mohammed MH, Basheer C, Siddiqui MN, Al-Arfaj A, Journal of Chemistry, 2015 (2015) 1-5.
27"Synthesis, characterization and anticancer activity of gold(I) complexes that contain tri-tert-butylphosphine and dialkyl dithiocarbamate ligands", Altaf M, Monim-ul-Mehboob M, Seliman AA, Sohail M, Wazeer MI, Isab AA, et al., Eur J Med Chem, 2015 (95) 464-72.
26"Synthesis, characterization and in vitro cytotoxicity of gold(iii) dialkyl/diaryldithiocarbamato complexes", Altaf M, Isab AA, Vančo J, Dvořák Z, Trávníček Z, Stoeckli-Evans H, RSC Adv, 2015 (5) 81599-607.
25"Single-step microwave assisted headspace liquid-phase microextraction of trihalomethanes and haloketones in biological samples", Alsharaa A, Basheer C, Sajid M, Journal of chromatography B, Analytical technologies in the biomedical and life sciences, 2015 (1007) 43-8.
24"Synthesis, characterization and theoretical calculations of (1,2-diaminocyclohexane)(1,3-diaminopropane)gold(III) chloride complexes: in vitro cytotoxic evaluations against human cancer cell lines", Al-Jaroudi SS, Altaf M, Al-Saadi AA, Kawde AN, Altuwaijri S, Ahmad S, et al., Biometals, 2015 (28) 827-44.
23"Microstructure and Properties of Spark Plasma Sintered Aluminum Containing 1 wt.% SiC Nanoparticles", Aliyu I, Saheb N, Hassan S, Al-Aqeeli N, Metals, 2015 (5) 70-83.
22"Co@Pt core–shell nanoparticles supported on carbon nanotubes as promising catalyst for methanol electro-oxidation", Ali S, Ahmed R, Sohail M, Khan SA, Ansari MS, Journal of Industrial and Engineering Chemistry, 2015 (28) 344-50.
21"Development of hierarchical EU-1 zeolite by sequential alkaline and acid treatments for selective dimethyl ether to propylene (DTP)", Ahmed MHM, Muraza O, Al-Amer AM, Miyake K, Nishiyama N, Applied Catalysis A: General, 2015 (497) 127-34.
20"Development of desilicated EU-1 zeolite and its application in conversion of dimethyl ether to olefins", Ahmed MHM, Muraza O, Al Amer AM, Sugiura Y, Nishiyama N, Microporous and Mesoporous Materials, 2015 (207) 9-16.
19"Synthesis, theoretical calculations and antimicrobial studies of copper(I) complexes of cysteamine, cysteine and 2-mercaptonicotinic acid", Ahmad S, Espinosa A, Ahmad T, Sohail M, Isab AA, Saleem M, et al., Polyhedron, 2015 (85) 239-45.
18"The rhodium complex of bis (diphenylphosphinomethyl) dopamine-coated magnetic nanoparticles as an efficient and reusable catalyst for hydroformylation of olefins", Shaikh MN, Bououdina M, Jimoh AA, Aziz MA, Helal A, Hakeem AS, et al., New Journal of Chemistry, 2015 (39) 7293-9.
17"Template-less surfactant-free hydrothermal synthesis NiO nanoflowers and their photoelectrochemical hydrogen production", Qurashi A, Zhang Z, Asif M, Yamazaki T, International Journal of Hydrogen Energy, 2015 (40) 15801-5.
16"Nanofiller graphene–ZnO hybrid nanoarchitecture: optical, electrical and optoelectronic investigation", Qurashi A, Subrahmanyam K, Kumar P, Journal of Materials Chemistry C, 2015 (3) 11959-64.
15"Swift electrochemical detection of paraben an endocrine disruptor by In2O3 nanobricks", Qurashi A, Rather JA, Yamazaki T, Sohail M, De Wael K, Merzougui B, et al., Sensors and Actuators B: Chemical, 2015 (221) 167-71.
14"Synthesis of Gd2O3:Eu nanoplatelets for MRI and fluorescence imaging", Maalej NM, Qurashi A, Assadi AA, Maalej R, Shaikh MN, Ilyas M, et al., Nanoscale Res Lett, 2015 (10) 215.
13"The nature and kinetics of the adsorption of dibenzothiophene in model diesel fuel on carbonaceous materials loaded with aluminum oxide particles", Nazal MK, Khaled M, Atieh MA, Aljundi IH, Oweimreen GA, Abulkibash AM, Arabian Journal of Chemistry, 2015.
12"Cadmium removal by activated carbon, carbon nanotubes, carbon nanofibers, and carbon fly ash: a comparative study", Al-Khaldi FA, Abu-Sharkh B, Abulkibash AM, Atieh MA, Desalination and Water Treatment, 2015 (53) 1417-29.
11"Visible light-induced photodegradation of rhodamine dyes over BiOCl, and the vital importance of the frontier orbital energy of the dye molecules in the reaction kinetics", Shen K, Gondal MA, Al-Saadi AA, Li L, Chang X, Xu Q, Research on Chemical Intermediates, 2015 (41) 2753-66.
10"Morphological, structural and optical properties of silver treated zinc oxide thin film", Drmosh QA, Hossain MK, Alharbi FH, Tabet N, J Mater Sci: Mater Electron, 2015 (26) 139-48.
9"Preparation of WO3/g-C3N4 composites and their enhanced photodegradation of contaminants in aqueous solution under visible light irradiation", Gondal MA, Adesida AA, Rashid SG, Shi S, Khan R, Yamani ZH, et al., Reaction Kinetics, Mechanisms and Catalysis, 2015 (114) 357-67.
8"Wetting and non-wetting behavior of abrasive paper for oil water separation and oil spill cleanup", Shi S, Sadullah MS, Gondal MA, Sui Y, Liu S, Yamani ZH, et al., Research on Chemical Intermediates, 2015 (41) 8019-29.
7"Towards sensor array materials: can failure be delayed?", Samir M, Nouari S, Shafique MAK, Khurram KQ, Science and Technology of Advanced Materials, 2015 (16) 034607.
6"Synthesis, morphology and antifungal activity of nano-particulated amphotericin-B, ketoconazole and thymoquinone against Candida albicans yeasts and Candida biofilm", Randhawa MA, Gondal MA, Al-Zahrani A-HJ, Rashid SG, Ali A, Journal of Environmental Science and Health, Part A, 2015 (50) 119-24.
5"Mechanical, Rheological and Thermal Properties of Polystyrene/1-Octadecanol Modified Carbon Nanotubes Nanocomposites", Amr IT, Al-Amer A, Thomas SP, Sougrat R, Atieh MA, Fullerenes, Nanotubes and Carbon Nanostructures, 2015 (23) 209-17.
4"A Pt-free Electrocatalyst Based on Pyrolized Vinazene-Carbon Composite for Oxygen Reduction Reaction", Akinpelu A, Merzougui B, Bukola S, Azad A-M, Basheer RA, Swain GM, et al., Electrochimica Acta, 2015 (161) 305-11.
3"Immobilization of yeast alcohol dehydrogenase on polyaniline coated silver nanoparticles formed by green synthesis", Alam MF, Laskar AA, Zubair M, Baig U, Younus H, Journal of Molecular Catalysis B: Enzymatic, 2015 (119) 78-84.
2"Photocatalytic conversion of CO2 into value-added hydrocarbon (methanol) with high selectivity over ZnS nanoparticles driven by 355-nm pulsed laser", Chang X, Zheng J, Gondal MA, Ji G, Research on Chemical Intermediates, 2015 (41) 739-47.
1"Removal of carcinogenic hexavalent chromium from aqueous solutions using newly synthesized and characterized polypyrrole–titanium(IV)phosphate nanocomposite", Baig U, Rao RAK, Khan AA, Sanagi MM, Gondal MA, Chemical Engineering Journal, 2015 (280) 494-504.