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21.
The sulfur dioxide adsorption on clinoptilolite-rich tuff from Bigadiç region of Western of Turkey and its modified forms (Na+, K+, Ca2+ and Mg2+) have been studied at 273 K and 293 K up to 100 kPa. The structural properties of clinoptilolites were studied by X-ray diffraction (XRD) and Fourier transform infrared (FT-IR). The quantitative XRD analysis demonstrated that the Natural-B sample is mainly constituted by clinoptilolite (80–85%) with minor contents of quartz (7–8%), feldspar (5–6%) and mica-illit (4–5%). It was found out that the adsorption capacity and the affinity of SO2 with clinoptilolite samples depended mainly on the type of exchanged cations and decreased as Na-B > K-B > Mg-B > Natural-B > Ca-B for both temperature. These results show that clinoptilolite-rich zeolites are considered potentially good adsorbents for SO2 removal. 相似文献
22.
Harrison N Alver U Goodrich RG Vekhter I Sarrao JL Pagliuso PG Moreno NO Balicas L Fisk Z Hall D Macaluso RT Chan JY 《Physical review letters》2004,93(18):186405
de Haas-van Alphen measurements on Ce(x)La(1-x)MIn(5) yield contrasting types of behavior that depend on whether M=Co and Ir or M=Rh. A stronger x-dependent scattering in the case of M=Co and Ir is suggestive of a stronger relative coupling, J/W, of the conduction electrons to the 4f electrons, which would then account for the development of a heavy composite Fermi-liquid state as x-->1. The failure of a composite Fermi-liquid state to form for any x in the case of M= Rh is shown to be inconsistent with theoretical models that propose antiferromagnetism to result from spin-density-wave formation. 相似文献
23.
B. Egrdoğan Alver M. Sakici E. Yörükoğullari Y. Yilmaz M. Güven 《Journal of Thermal Analysis and Calorimetry》2008,94(3):835-840
The water adsorption properties of sepiolite having dolomite supplied from Eskisehir region and their exchanged forms (K+, Na+, Mg2+ and Ca2+) were investigated. The sepiolite samples were characterized using XRD, TG-DTA, DSC and nitrogen adsorption methods. The
temperature ranges were determined for the dehydrations of hydroscopic and zeolitic water as 30–200°C, for the dehydration
of the bound water as 250–750°C and for the dehydroxylation of hydroxyls as 810–850°C in the sample. It was observed that
the value of percent mass loss for natural and modified samples varied in the range from 36.70 to 39.05%. Two mass loss steps
for all samples were observed using a differential scanning calorimetry (DSC) in the range of 30–550°C. Adsorption isotherms
for water on natural and modified forms were obtained at pressures up to 2.39 kPa. Uptake of water increased as K-SEP.<Na-SEP.<Mg-SEP.<Ca-SEP.
for sepiolite samples at 293 K. 相似文献
24.
Mehmet Aydın Ülkü Alver Şahin 《International journal of environmental analytical chemistry》2017,97(4):368-382
This study details the metal and metalloid accumulation profiles of three species of sea cucumbers (Holothuriamammata, Holothuriapolii and Holothuriatubulosa) native to Alia?a and Ild?r (?zmir, Turkey), two regions that are representative of industrial and residential districts, respectively. A total of 11 elements were analysed (Fe, Cu, Mn, Zn, Cr, Co, V, Ni, Cd, Pb and As) from gut and body wall tissues of holothurians and in sediment samples. The Mann–Whitney U analysis revealed statistical difference between locations and tissues. Accumulations of Alia?a samples were significantly higher than Ild?r samples with respect to Zn, V, Mn, Cr, Fe and Co while accumulations were significantly higher in the gut than body wall regardless of the region for all elements tested. The correlation analysis showed more and stronger correlations in the gut than in the body wall. In addition, metal(loid) concentrations in the sediment were found to correlate strongly with these in the sea cucumber gut. The cluster analysis displayed totally different element accumulation pattern for Alia?a and Ild?r in the both tissues which indicate that anthropogenic effects start to alter the bioaccumulation of metal(loids). Biota-sediment accumulation factors (BSAF) and metal contamination index were calculated to determine the extent of metal(loid) uptake and to compare total elemental accumulation at each region. Gut tissue elemental BSAF is higher than body wall for all elements at both areas. Cd has the highest value with 5.582 (gut tissue) and the lowest are Ni, V and Cr with 0.001 (body wall tissue). In addition, sediment results were compared with previous studies and sediment quality guidelines and found to exceed the lowest effect level (LEL) values for As and Ni. 相似文献
25.
Cemal Parlak Gürkan Keşan Nadide Kazancı Lydia Rhyman Özgür Alver 《Physics and Chemistry of Liquids》2017,55(4):532-540
Conformers of N-methacryloyl-(L)-glutamic acid (MAGA, C9H13NO5) in the gas phase, benzene or methanol environment were searched by the density functional theory (DFT) and time-dependent DFT. Selected conformational isomers based on potential energy surface analysis were studied by considering the structural and electronic properties. B3LYP functional, and HF and MP2 levels were used with the 6-31+G(d,p), 6-311+G(3df,p) and aug-cc-pVDZ basis sets. We explored the effect of medium on the conformational preferences, UV spectra and frontier molecular orbitals of the conformers. The outcomes of this research will be useful for future studies including moieties analogous to MAGA. 相似文献
26.
Parlak C Alver O Senyel M 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2008,69(4):1252-1256
(1)H, (13)C, DEPT, COSY, NOESY and HETCOR NMR spectra of 4-(3-cyclohexen-1-yl)pyridine (4-Chpy) have been reported for the first time. (1)H and (13)C NMR chemical shifts of 4-Chpy (C(11)H(13)N) have been calculated by means of the Hartree-Fock (HF) and Becke-3-Lee-Yang-Parr (B3LYP) density functional methods with 6-311++G(d,p) basis set. Comparison between the experimental and the theoretical results indicate that density functional B3LYP method is superior to the scaled HF approach for predicting NMR properties. 相似文献
27.
Özgür Alver 《Magnetic resonance in chemistry : MRC》2010,48(1):53-60
The possible stable forms and molecular structures of 1‐cyclohexylpiperazine (1‐chpp) and 1‐(4‐pyridyl)piperazine (1‐4pypp) molecules have been studied experimentally and theoretically using nuclear magnetic resonance(NMR) spectroscopy. 13C, 15N cross‐polarization magic‐angle spinning NMR and liquid phase1H, 13C, DEPT, COSY, HETCOR and INADEQUATE NMR spectra of 1‐chpp (C10H20N2) and 1‐4pypp (C9H13N2) have been reported. Solvent effects on nuclear magnetic shielding tensors have been investigated using CDCl3, CD3 OD, dimethylsulfoxide (DMSO)‐d6, (CD3)2CO, D2O and CD2Cl2. 1H and 13C NMR chemical shifts have been calculated for the most stable two conformers, equatorial–equatorial (e–e) and axial–equatorial (a–e) forms of 1‐chpp and 1‐4pypp using B3LYP/6‐311++G(d,p)//6‐31G(d) level of theory. Results from experimental and theoretical data showed that the molecular geometry and the mole fractions of stable conformers of both molecules are solvent dependent. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
28.
B. Alver B. B. Back M. D. Baker M. Ballintijn D. S. Barton R. R. Betts A. A. Bickley R. Bindel W. Busza A. Carroll Z. Chai V. Chetluru M. P. Decowski E. García T. Gburek N. George K. Gulbrandsen C. Halliwell J. Hamblen I. Harnarine M. Hauer C. Henderson D. J. Hofman R. S. Hollis R. Holyński B. Holzman A. Iordanova E. Johnson J. L. Kane N. Khan P. Kulinich C. M. Kuo W. Li W. T. Lin C. Loizides S. Manly A. C. Mignerey R. Nouicer A. Olszewski R. Pak C. Reed E. Richardson C. Roland G. Roland J. Sagerer H. Seals I. Sedykh C. E. Smith M. A. Stankiewicz P. Steinberg G. S. F. Stephans A. Sukhanov A. Szostak M. B. Tonjes A. Trzupek C. Vale G. J. van Nieuwenhuizen S. S. Vaurynovich R. Verdier G. I. Veres P. Walters E. Wenger D. Willhelm F. L. H. Wolfs B. Wosiek K. Wo?niak S. Wyngaardt B. Wys?ouch 《The European Physical Journal C - Particles and Fields》2009,61(4):575-582
A selection of experimental results from the PHOBOS Collaboration relevant for probing high-energy nuclear collisions with
high transverse momentum particles is presented. The inclusive yields of charged particles and comparisons between nuclear
and elementary collisions already reveal a large amount of parton energy loss in the hot and dense medium created in heavy
ion collisions. Remarkable scaling and factorization features are observed, unifying the data taken at various collision energies,
centralities and nuclear sizes. To further analyze the nature of the energy loss, a measurement of pseudorapidity (Δη) and azimuthal angle (Δφ) correlations between high transverse momentum charged hadrons (p
T
>2.5 GeV/c) and all associated charged particles is presented at both short-range (small Δη) and long-range (large Δη) over a continuous detector acceptance covering −4<Δη<2. Various near- and away-side features of the correlation structure are discussed as a function of centrality in Au + Au
collisions at
GeV. The results provide new information about the longitudinal (Δη) extent of the near-side ‘ridge’ structure, first observed by the STAR Collaboration over a narrower η range. In central Au + Au collisions the ridge structure extends to at least Δη=4, and its strength completely diminishes as collisions become more peripheral.
Presenter of the paper on the 3rd International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions,
8–14 June 2008, Illa da Toxa (Galicia-Spain). 相似文献