Keles Güner, Eda; Ertugay, Nese; Ozdemir, Agah Oktay; Doğan, Bilge; Caglar, Bulent

The photocatalysis process, which is effective, economical, and environmentally friendly can overcome rapidly increasing environmental problems, has shown rapid development in recent years. Nontoxic, low-cost natural minerals are often used in photocatalysis processes that remove organic pollution from wastewater. In this study, a selective method for the removal of crystal violet (CV) from aqueous solutions using nanocomposite of nickel oxide/zinc oxide nanoparticles (NiO/ZnO) supported on kaolinite photocatalyst was investigated. The raw kaolinite, bare NiO, bare ZnO and nanocomposite samples were characterized by the XRD, TEM, SEM-EDX, XPS and FTIR techniques. The photocatalytic performances of kaolinite-NiOZnO (K-NiO/ZnO) nanocomposite and bare samples were also investigated and comparatively evaluated by the photodegradation of CV (cationic dye) dye under visible light irradiation. The effects of various parameters such as the dosage of photocatalysis, contact time, and initial dye concentration on the rate of removal of dye were investigated and optimized. The kinetics of decolorization by samples can be well described by the pseudo-first-order model. Finally, it can be used in advanced oxidative processes for the degradation of organic pollutants.

Koksal, E.; Afsin, B.; Tabak, A.; Caglar, B.

The acid activation process increased the specific surface area of raw Resadiye bentonite (33.5 m2/g) by ∼ 4-fold whereas the interaction with n-butylamine caused a surface area reduction of acid-activated bentonite by 40% along with the broadening of the Si-O stretching peak at 1041 cm−1 and the decrease of the d001 value from 14.5 to 13.5 Å. The thermal analysis data confirmed the stability of the mesoporous n-butylamine/acid-activated bentonite composite up to 499 °C which was followed by the cleavage of the interlayer n-butylamine species between 500 and 700 °C.

Aksoy, Canan; Kabaoğlu, Hatice; Şahin Timar, Zeynep; Binay, Eren; Aksoy, Handan; Tıraşoğlu, Engin

Purpose: The most consumed urban crops having many benefits for human health in the northeast Black Sea black cabbage (Brassica oleracea L.var.acephale) leaf and theirs own grown soils were collected from Black Sea cities and towns; Rize, Trabzon, Giresun, Ordu ve Samsun of Turkey from totally 55 stations to determine the element levels in percent of the black cabbage. It is purposed that to obtain the data for each city in terms of element distribution. This study is a very comprehensive work covering almost the entire eastern Black Sea region for elemental measurements in black cabbage and its soil and comparing them between provinces and districts. Method: The samples were analyzed by using Energy Dispersive X-Ray Fluorescence (EDXRF) technique that is a nondestructive method by giving reliable results. The obtained data were evaluated by using the ordinary cricking method and some statistical methods (Mann-Whitney- U Test, Oneway-ANOVA, Pearson and Spearman-Brown correlation test) to determine the correlations between soils, the black cabbage and both compared the element levels between the sampling points. The statistical analysis in soil and black cabbage samples were carried out for 19 and 11 elements, respectively. Results: Mg (Magnesium), K (Potassium), Ca (Calcium), Al (Aluminum), Si (Silica), P (Phosphor), S (Sulphur), Ti (Titanium), Fe (Iron), Sr (Strontium), V (Vanadium), Cr (Chromium), Mn (Manganese) for the black cabbage sample and Na (Sodium), Mg, Al, Si, P, S, K, Ca, Ti, Fe, Cu (Copper), Zn (Zinc), Sr, V, Cr, Mn, As (Arsenic), Rb (Rubidium) and Pb (Lead) for soil samples were determined. The determining elements for soils and the black cabbage samples were compared between the working provinces. Conclusions: The obtained data showed that the element distribution is similar and not showed a statistical difference for both between each station and cities. Besides, the trace elements in soils are not much affected the black cabbage however Al was found in the cabbage even it is less.

Akkuş, Tuba; Yılmaz, Demet; Şahin, Yusuf

Samarium, hafnium, and lead have great importance in making various absorbent materials. The L X-ray differential cross-sections of samarium, hafnium, and lead were measured within the range of 85° ≤ θ ≤ 135° with steps of 10° at 59.54 kiloelectron volt (keV) photon energy. In this study, angular dependence of L X-rays is explained by differential cross-section and intensity ratio calculations. The Lγ X-rays were found depend on the scattering angles weakly; therefore, we found reasonable to give the ratio to the Lγ X-rays. The anisotropy observed in the LI and Lα X-rays but is not observed in Lβ and Lγ X-rays.

Yılmaz, Demet; Güzeldir, Betül; Akkuş, Tuba; Öznülüer, Tuba

Thickness and composition of thin films can be measured with X- and gamma-rays. In this work, thickness and composition of vanadium pentoxide thin films are investigated by energy dispersive and wavelength dispersive X-ray fluorescence systems. Also, the surface analysis of vanadium pentoxide thin films irradiated with Rhodium Kα X-rays and 59.54 keV gamma-rays emitted from 100 mCi and 5 Ci Americium-241 radioactive sources is performed by scanning electron microscope. It is observed that X- and gamma-rays are destructive for vanadium pentoxide thin films. Also, the composition of vanadium pentoxide thin films changes by irradiation with X- and gamma-rays.

Porikli, Sevil; Han, Ibrahim; Yalçin, Pa̧sa; Kurucu, Yakup

It is clear that detailed studies performed under identical experimental conditions are desirable to determine the effect of the chemical environment on the value of intensity ratios. To better understand this effect, we conducted measurements on Kβ1/Kα, Kβ2/Kα Kβ2/Kβ1 and Kβ/Kα x-ray intensity ratios. The Kα and Kβ1,2 emission spectra for compounds of 4d transition metals Y, Zr, Nb, and Mo were measured using a Si(Li) solid-state detector. The samples were excited by 22.69keV x-rays emitted from a 109Cd radioisotopes source. The experimental results for pure elements are compared with the other experimental and theoretical values.

Koksal, E.; Afsin, B.; Tabak, A.; Caglar, B.

The aniline species incorporated into the acid-activated bentonite matrices leads to the decay of the skeletal stretches centered at 1041 cm-1 and the rise of new features in the phenyl ring frequency region, 1700-1400 cm-1, demonstrates clearly the influence of the acid activation on the Lewis sites necessary for coordination of aniline to bentonite. The exothermic DTA features at 507, 684, and 725°C indicate the release of both the clusters and the decomposed fragments of the aniline-clay composite, and the highly stable carbonaceous residue, respectively. The basal difference by ∼1.0 nm and the much smaller surface area (33.8 m2/g) than that of the nonintercalated bentonite (129.2 m2/g) prove the presence of the tilted aniline species between the interlamellar grooves of the bentonite framework.

Erzeneoǧlu, Salih; Içelli, Orhan; Şahin, Yusuf

Differential cross sections for coherent scattering of 59.5 keV gamma rays at 115° were measured for 12 elements in atomic range 26≤Z≤82. Experimental results were compared with theoretical values.