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1.
Composite of polyacrylamide-bentonite (PAA-B) was prepared by direct polymerisation of PAA in a suspension of bentonite (B). Adsorption and thermodynamic features of phytic acid (Phy) adsorption onto B, PAA and PAA-B, and those of Fe3+, Zn2+, UO2
2+ adsorption onto PAA-B and its modification by Phy (PAA-B-Phy) have been investigated. The reusability, storagability, ion selectivity and recoverability of sorbed ions with 1 M HCl have also been considered.The chemical and physical structure of adsorbents has been characterised by means of FT-IR and XRD. All adsorption isotherms for Phy and the ions were L-type of the Giles classification except, the one which is S type for adsorption of Phy onto PAA. The maximum adsorption capacities for the ions adsorbed were in order of UO2
2+ > Fe3+ > Zn2+ for PAA-B and Zn2+ > Fe3+ > UO2
2+ for PAA-B-Phy. Langmuir equilibrium constants for the adsorption of ions onto PAA-B-Phy were significantly higher than those found for PAA-B; the magnitude of increase for UO2
2+ was about 100. The thermodynamic parameters indicated that adsorption reactions are spontaneous in terms of adsorption free enthalpy.The chemical structure of PAA-B-Phy was not changed at the end of the studies of reusability and storagability. The composite was selective for UO2
2+ of the ions of interest.The composite of PAA-B and its modification by Phy have been used for the first time in this investigation. It is proposed that the composites can be practically used in the investigations and applications of adsorption. 相似文献
2.
Nuray Ulusoy Muammer Kiraz Ömer Küçükbasmacı 《Monatshefte für Chemie / Chemical Monthly》2002,133(10):1305-1315
Summary. New 4-alkyl/aryl-1-((6-(4-bromophenyl)-imidazo[2,1-b]thiazol-3-yl)-acetyl)-3-thiosemicarbazides and 3-alkyl/aryl-2-(((6-(4-bromophenyl)-imidazo[2,1-b]thiazol-3-yl)-acetyl)-hydrazono)-4-thiazolidinones were synthesized from 6-(4-bromophenyl)-imidazo[2,1-b]thiazole-3-acetic acid hydrazide. Their structures were elucidated by elemental analyses and spectroscopic data. All compounds
were tested for antibacterial and antifungal activities. The antimicrobial activities of the compounds were assessed by the
microbroth dilution technique. The compounds were also evaluated for antituberculosis activity against Mycobacterium tuberculosis H37Rv (ATCC 27294); they exhibited varying degrees of inhibition in the in vitro primary screening at 6.25 μg · cm−3. The most active compound was 3-(4-nitrophenyl)-2-(((6-(4-bromophenyl)-imidazo[2,1-b]thiazol-3-yl)-acetyl)-hydrazono)-4-thiazolidinone.
Corresponding author. E-mail: nurayulusoy@yahoo.com
Received December 10, 2001. Accepted (revised) March 1, 2002 相似文献
3.
Gizem Kaleli‐Can Busra Ozlu Hatice Ferda
zgüzar Baran Onal‐Ulusoy Gzde Kabay Taesik Eom Bong Sup Shim Mehmet Mutlu 《Electroanalysis》2020,32(8):1696-1706
A biosensor was prepared with natural melanin nanoparticles (MNP) decorated on a screen‐printed carbon electrode (SPCE). Hexavalent chromium was selected as a well‐known heavy metal ion to be detected for testing the performance of novel biosensor. Natural MNP was extracted from cuttlefish (Sepia officinalis) ink. Surface decoration of SPCEs with MNP was performed by two different methods. The first one was layer‐by‐layer assembly (LBL‐A) for different cycle times(n). In the second one, plasma treatment of SPCE incorporated with evaporation‐induced self‐assembly (EI‐SA) techniques including different incubation times in MNP solutions. The performance of both modified SPCEs were tested for amperometric detection of Cr(VI) in various water samples, and peak reduction of Cr(VI) was determined at 0.33 V. Amperometric results showed wide linear ranges of 0.1–2 μM and 0.1–5 μM of Cr(VI) for SPCEs modified with 14n‐LBL‐A and 12h‐EI‐SA, respectively. The sensitivities of SPCEs modified with 14n‐LBL‐A and 12h‐EI‐SA techniques were 0.27 μA μM?1 and 0.52 μA μM?1, respectively. In addition, both modified SPCEs selectively detected Cr(VI) in a model aqueous system composed of certain other heavy metals and minerals, and tap and lake water samples. The LOD and LOQ values for 12h‐EI‐SA were 0.03 μM and 0.1 μM, respectively. This showed that MNP‐modified‐SPCEs generated via EI‐SA techniques have the potential to be an alternative to conventional detection methods such as ICP‐MS. 相似文献
4.
This paper considers multiprocessor task scheduling in a multistage hybrid flow-shop environment. The objective is to minimize the make-span, that is, the completion time of all the tasks in the last stage. This problem is of practical interest in the textile and process industries. A genetic algorithm (GA) is developed to solve the problem. The GA is tested against a lower bound from the literature as well as against heuristic rules on a test bed comprising 400 problems with up to 100 jobs, 10 stages, and with up to five processors on each stage. For small problems, solutions found by the GA are compared to optimal solutions, which are obtained by total enumeration. For larger problems, optimum solutions are estimated by a statistical prediction technique. Computational results show that the GA is both effective and efficient for the current problem. Test problems are provided in a web site at www.benchmark.ibu.edu.tr/mpt-hfsp. 相似文献
5.
T. Gamze Ulusoy Ghobadi Amir Ghobadi Merve Demirtas Muhammed Buyuktemiz Kubra N. Ozvural Elif Akhuseyin Yildiz Prof. Emre Erdem Prof. H. Gul Yaglioglu Prof. Engin Durgun Prof. Yavuz Dede Prof. Ekmel Ozbay Prof. Ferdi Karadas 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(35):8966-8976
The replacement of traditional ruthenium-based photosensitizers with low-cost and abundant iron analogs is a key step for the advancement of scalable and sustainable dye-sensitized water splitting cells. In this proof-of-concept study, a pyridinium ligand coordinated pentacyanoferrate(II) chromophore is used to construct a cyanide-based CoFe extended bulk framework, in which the iron photosensitizer units are connected to cobalt water oxidation catalytic sites through cyanide linkers. The iron-sensitized photoanode exhibits exceptional stability for at least 5 h at pH 7 and features its photosensitizing ability with an incident photon-to-current conversion capacity up to 500 nm with nanosecond scale excited state lifetime. Ultrafast transient absorption and computational studies reveal that iron and cobalt sites mutually support each other for charge separation via short bridging cyanide groups and for injection to the semiconductor in our proof-of-concept photoelectrochemical device. The reorganization of the excited states due to the mixing of electronic states of metal-based orbitals subsequently tailor the electron transfer cascade during the photoelectrochemical process. This breakthrough in chromophore-catalyst assemblies will spark interest in dye-sensitization with robust bulk systems for photoconversion applications. 相似文献
6.
Cationic diimine Ru(II) complexes were synthesized and tested as catalysts for the formation of cyclic organic carbonates from CO2 and liquid epoxides (propylene oxide, epichlorohydrine, 1,2‐epoxybutane and styrene oxide) which served as both reactant and solvent. The reaction rates not only depended on the type of ligand, but also on reaction conditions such as temperature, pressure, base, the epoxide substrates and the use of an additional solvent. Reaction rates in terms of turnover frequencies up to 4050 molproduct molcat.?1 h?1 at 99% selectivity were achieved by optimizing the diimine ligand as well as the reaction temperature and CO2 pressure. Consistent with CV measurements, the electron donating group on the p‐position of the aryl ring accelerated the reaction rate. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
7.
8.
Ulvi Yurtsever 《Foundations of Physics》1983,13(5):529-537
Among the problems C. D. Bailey has questioned in a recent paper (Ref. 1) are a precise and general formulation of Hamilton's variational principle and the establishment of a sufficiency criterion for this to be a minimum principle. In this paper, we will try to answer these questions using the geometric theory of classical mechanics. 相似文献
9.
Sterically hindered salicylaldimine functionalized imidazolium salts 2 have been prepared. The structures of the synthesized compounds were determined by spectroscopic techniques. The reaction of these salts containing arylmethyl-N chain (aryl: phenyl (2a), 2,4,6-trimethylphenyl (2b), 2,3,4,5,6-pentamethylphenyl (2c)) with Pd(OAc)2 in boiling toluene afforded Pd(II) complexes 3 in high yields. The X-ray structure of 1-[3-(3,5-di-tert-butyl-2-oxophenyl)propyliminato]-3-(2,4,6-trimethylbenzyl)imidazol-2-ylidenebromopalladium(II) (3b) has been determined. The Suzuki-Miyaura reaction was used to investigate their activity as catalysts either prepared in situ or from well-defined complexes. They are efficient when activated arylbromides are used as substrates. 相似文献
10.
Mahmut Ulusoy Hasan Karabıyık Rafet Kılınçarslan Muhittin Aygün Bekir Çetinkaya Santiago García-Granda 《Structural chemistry》2008,19(5):749-755
Copper(II) and cobalt(II) complexes of salicylaldimine obtained by the condensation of N,N-diethyl-2-methyl-1,4-phenylenediamine with 3,5-di-tert-butyl-2-hydroxybenzaldehyde have been synthesized and characterized by elemental analyses, magnetic susceptibility measurements,
cyclic voltammetry, and FT-IR and UV–Vis spectroscopy. The molecular structure of the title copper(II) complex was determined
by the single crystal X-ray diffraction technique. The Cu(II) center is coordinated by four atoms of the donor set in a compressed
tetrahedral trans-[N2O2] environment, which can be essentially ascribed to the presence of bulky fragments of the ligand. The computed bond valences
of the copper verify +2 oxidation state and indicate that the copper bonds, in particular Cu–N bonds, are elongated due to
steric effects from bulky substituents in the ligands, N-(4-diethylamino-2-methylphenyl). Intermolecular C–H···π interactions leading to centrosymmetric synthons serve to stabilize
periodic organization of the molecules. 相似文献