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41.
Swelling studies of copolymeric acrylamide/crotonic acid hydrogels as carriers for agricultural uses
In this study, highly swollen acrylamide/crotonic acid hydrogels (in a rod form) containing some inorganic salts such as ammonium nitrate, potassium nitrate and ammonium sulphate used as fertilizer, an agricultural drug such as Dalapon (sodium 2,2‐dichloropropionate) and two crosslinkers such as ethylene glycol dimethacrylate and 1,4‐butandiol dimethacrylate were prepared by copolymerization of acrylamide and crotonic acid with γ‐radiation. As a result of swelling tests, the influence of γ‐ray dose and relative content of crotonic acid on the swelling properties, the diffusional behavior of water, diffusion coefficients and network properties of the hydrogel systems were examined. Acrylamide/crotonic acid hydrogels containing these salts and agricultural drug were swollen in the range 2045–400% in water, while polyacrylamide hydrogels swelled in the range 660–700%. Water intake of hydrogels followed a nonFickian‐type diffusion. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
42.
Yasemin Ö. Çiftci Kemal Çolakoğlu Sefa Kazanç SonerÖzgen 《Central European Journal of Physics》2006,4(4):472-480
This paper describes the effect of pressure on some the mechanical properties of transition metals Cu, Ag, and Au, such as
elastic constants and bulk modulus. Using molecular dynamics (MD) simulation, the present study was carried out using the
modified many-body Morse potential function expression in the framework of the Embedded Atom Method (EAM). The effect of pressure
on equilibrium volume, elastic constants, and bulk modulus were determined, and found to be in agreement with other theoretical
calculations and experimental data. 相似文献
43.
Effect of indium incorporation on the optical properties of spray pyrolyzed Cd0.22Zn0.78S thin films
Mujdat Caglar Muhsin Zor Saliha Ilican Yasemin Caglar 《Czechoslovak Journal of Physics》2006,56(3):277-287
In this study, effect of indium incorporation on the optical properties is investigated for the spray pyrolyzed onto glass
substrates at 275°C substrate temperature undoped and indium doped Cd0.22Zn0.78S thin films. The average optical transmittance of all the films was over 77% in the wavelength range between 450 and 800
nm. The optical band gap energies of the thin films have been investigated by the measurement of the optical absorbance as
a function of wavelength. The optical absorption studies reveal that the transitions are direct band gaps of 3.02 and 3.05
eV for undoped and doped indium Cd0.22Zn0.78S thin films, respectively. The Urbach tail parameter and optical constants such as refractive index, extinction coefficient,
and dielectric constants were calculated for these films. The dispersion parameters such as single-oscillator energy and dispersive
energy were discussed in terms oft he single-oscillator Wemple—DiDomenico model. 相似文献
44.
Yasemin Serin 《Operations Research Letters》2007,35(1):83-94
Consider two newsvendors: (i) they compete satisfying substitutable demands searching Nash equilibrium or (ii) one is the leader deciding first, the other responds optimally playing a Stackelberg game. The leader profits more than she does in (i). We present conditions under which the leader's profit does not improve from (i) to (ii). 相似文献
45.
Elif Gungor Mustafa Burak Coban Hulya Kara Yasemin Acar 《Journal of Cluster Science》2018,29(3):533-540
A new open-cubane MnIII, [{(H2O)MnIIIL}{MnIIIL}]2·2(CH3OH).2(CH3CH2OH)·2Cl, 1 where H 2 L=[N-(2-hydroxyethyl)-3-methoxysalicylaldimine] has been synthesized and characterized by element analysis, FT-IR, solid UV–Vis spectroscopy and single crystal X-ray diffraction. The crystal structure determination shows an open-cubane tetranuclear complex. The Mn1 (Mn1i) ions is hexacoordinate by NO5 donor sets while the Mn2 (Mn2i) is pentacoordinate by NO4 donor sets. The solid state photoluminescence properties of complex 1 and its ligand H 2 L have been investigated under UV light at 349 nm in the visible region. H 2 L exhibits blue emission while complex 1 shows orange-red emission at room temperature. Variable-temperature magnetic susceptibility measurements on the complex 1 in the range 2–300 K indicate an antiferromagnetic interaction. 相似文献
46.
In this study, a syringe-connected minicolumn resin was used for the separation and enrichment of cadmium, copper, nickel and zinc prior to their determination by flame atomic absorption spectrometry. The proposed technique was compared with classical batch and column techniques in terms of rapidness, simplicity, enrichment and risk of contamination. The minicolumn was filled with Chromosorb-103 resin and connected to a syringe. If the samples were treated with ammonium pyrrolidine dithiocarbamate or 8-hydroxyquinoline, the analytes were quantitatively retained at pH2 and pH5 on the resin, respectively. On the other hand, if no chelating agent was added, the analytes were quantitatively retained at pH10. The analytes retained by the resin were quantitatively eluted by drawing and discharging nitric acid in acetone. The analytes in spiked river-water samples and in certified standard reference Bovine-Liver (NIST SRM 1577 b) were quantitatively (94%) recovered. The relative standard deviations for the determinations were found to be 1.0–10%. 相似文献
47.
48.
In this paper, the homotopy perturbation method (HPM) is developed to obtain approximate analytical solutions of a fractional Boussinesq equation with initial condition. The fractional derivatives are described in the Caputo sense. Some examples are given and comparisons are made, the comparisons show that the HPM is very effective and convenient and overcomes the difficulty of traditional methods. The numerical results show that the approaches are easy to implement and accurate when applied to space‐ and time‐fractional equations. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
49.
H. Yasemin Yenilmez Belkıs Ustamehmetoğlu Esma Sezer Zehra Altuntaş Bayır 《Journal of Solid State Electrochemistry》2018,22(2):505-517
The syntheses of new cobalt and zinc phthalocyanine complexes containing carbazole (Cz) substituents at the peripheral positions are reported (CzCoPc and CzZnPc). The reaction of Cz with 4-iodophthalonitrile in the presence of a catalytic amount of copper(I) oxide and potassium carbonate led to the formation of 4-(9H-carbazol-9-yl) phthalonitrile. Furthermore, by heating the dinitrile and anhydrous metal salts (CoCl2, Zn(CH3COO)2) at 160 °C in n-hexanol in the presence of DBU, the phthalocyanines were obtained. They were characterised by 1H NMR, FT-IR, UV-Vis and MS spectroscopic data. Aggregation behaviours of Pcs were investigated in THF. Electrochemical redox behaviour of CzCoPc was investigated by cyclic voltammetry depending on the potential range, and the oxidation and reduction products were followed by UV-Visible absorption measurements. Polymerisation of CzCoPc was carried out by potentiodynamic methods on glassy carbon electrode, and the catalytic activity of resulting polymer (P[CzCoPc]) was tested comparatively with polycarbazole (PCz)-coated electrode for dopamine and better response was obtained for P[CzCoPc] modified electrode. 相似文献
50.
In situ electrochemical synthesis of an organic-inorganic hybrid material composed of poly(3,4-ethylenedioxythiophene) (PEDOT) and nickel-based Keggin type polyoxometalate, K7[NiIIINiII(H2O)W11O39].15H2O(NiPOM), has been proposed here. The remarkable optical and electrical properties of the PEDOT and the unique redox properties of NiPOM have synergistically combined to make the hybrid structure highly desired multi-functional materials for a myriad of applications. The driving force for the formation of hybrid structure is thought to be electrostatic interactions between POM anions and cationic polaron/bipolaron structures that in the PEDOT. PEDOT/NiPOM based hybrid composite modified graphite electrode has been used for non-enzymatic glucose sensor platform as a sample of applications. Furthermore, PEDOT/NiPOM based sensor platform was successfully utilized for detection of glucose content with the lowest detection limit in real samples like honey and milk. These results suggest that PEDOT/NiPOM metal-organic hybrid composite could be utilized as multi-functional material for a myriad of applications. 相似文献