Ultrasound-assisted photocatalytic decomposition of rifadin with biochar and CNT-based NiCr layered double hydroxides

Mehmet KOBYA

Modification of layered double hydroxides (LDHs) is known to be beneficial for boosting the consistent formation of reactive oxygen species (ROSs) and enhancing the photocatalytic process. Herein, a facile synthesis method for preparing carbon nanotube (CNT) and biochar (BC)-based NiCr LDH (NC) nanocomposites as a sonophotocatalyst for the efficient degradation of rifadin (RA) was provided. The formation of thin nanosheet structures of NC along with porous and nanotube structures of BC and CNT was well approved by scanning electron microscope (SEM) and high-resolution transmission electron mic ...Более

A techno-economical assessment of treatment by coagulation-flocculation with aluminum and iron-bases coagulants of landfill leachate membrane concentrates

Mehmet KOBYA

Landfill leachate treatment involved with the membrane bioreactor (MBR) combined with membrane treatment via nanofiltration (NF) and/or reverse osmosis (RO) is widely used in Turkey. This treatment produces landfill leachate membrane concentrates (LLMCs) with an undesirably high concentration of contaminants. In the study, two different nanofiltration concentrates of leachate were coagulated. Coagulant dosages from 0.10 to 5.0 g of Me3/L (Me3: Al3 or Fe3), and the pH values ranged from 4.0 to 8.0 and 3.0-9.0 for Al-based and Fe-based coagulants, respectively. The most efficient pH values were ...Более

Perfluorooctanoic acid (PFOA) removal from real landfill leachate wastewater and simulated soil leachate by electrochemical oxidation process

Mehmet KOBYA

Poly and perfluoroalkyl compounds (PFASs) are a group of chemicals that are widely used and are difficult to purify. Within this group, perfluorooctanoic acid (PFOA), known for its highly polar and strong carbon-fluorine bonds, is a frequently encountered species in surface water, drinking water, and groundwater. In this study, we investigated the efficiency of electrooxidation (EO) in PFOA removal, optimization of EO parameters, and groundwater simulation in a realistic scenario. The EO optimization experiments were performed with a boron-doped diamond (BDD) anode for different values of pH, ...Более

Broadband, Stable, and Noniterative Dielectric Constant Measurement of Low-Loss Dielectric Slabs Using a Frequency-Domain Free-Space Method

Mehmet ERTUĞRUL

A broadband, stable, and noniterative free-space method is proposed for dielectric constant ε′r determination of low-loss dielectric slabs from reflection-only measurements through simple calibration standards (reflect and air). It is applicable for dispersive samples and does not require thickness information. Simulations of nondisperive and dispersive samples are performed to validate our method. Dielectric constant measurements of polyethylene and polyoxymethylene samples (9–11 GHz) are carried out to examine the accuracy of our method.

Synergistic effect of Fe and Co metals for the enhanced activation of hydrogen peroxide in the heterogeneous electro-Fenton process by Co-doped ZnFe layered double hydroxide

Mehmet KOBYA

Heterogeneous electro-Fenton (EF) is a powerful technology for the removal of emerging organic pollutants from wastewater. However, the development of catalysts with high activity towards the production of •OH by decomposing H2O2 remains a challenge. Herein, Co-doped ZnFe LDH as a heterogeneous catalyst with 2D plate-like morphology was produced by a co-precipitation method. Co-doping increased the pore volume of ZnFe LDH from 0.188 cm3/g to 0.2711 cm3/g and pore diameter from 5.305 nm and 9.39 nm. EF process consisted of a hydrothermally activated graphite felt cathode and a platinum plate an ...Более

Waveform Correlation Based Harmonic Voltage Contribution Determination of Iron and Steel Plants Supplied From PCC

Özgül SALOR-DURNA

In this research work, a new method which determines the individual harmonic voltage contributions of the EAF plants supplied from a point of common coupling (PCC) to the PCC voltage is presented. EAFs are one of the most significant sources of the harmonics, especially the uncharacteristic ones, therefore it is important to be able to discriminate the amount of individual contributions from the feeders of a PCC supplying multiple EAFs. The proposed method uses the relationship derived between the correlation coefficient of the PCC voltage and the feeder current waveforms and the harmonic volt ...Более

A novel carbohydrate antigen 125 electrochemical sensor based on sweet almond oil organo-hydrogels

Nahit AKTAŞ

Ovarian cancer is a gynecological disease causing many deaths among women around the world. Carbohydrate antigen 125 (CA-125) is a single biomarker known to be a tumor marker of ovarian cancer. CA-125 is widely used to monitor the treatment process, recurrences, and for the detection of ovarian cancer. Herein, organo-hydrogels were prepared in order to detect CA-125 sensitively in serum medium with electrochemical methods. Organo-hydrogels were obtained by the free radical polymerization reaction using agar and glycerol with varying proportions of sweet almond oil using methylene bisacrylamide ...Более

Identifying Geogenic and Anthropogenic Aluminum Pollution on Different Spatial Distributions and Removal of Natural Waters and Soil in Canakkale, Turkey

Mehmet KOBYA

The Çanakkale–Kirazlı region (Turkey) is enriched with minerals, especially aluminum (Al), which dangerously get transported into aquatic media due to several mining and geological activities in recent years. In this study, Al and other potentially toxic metals (PTMs) including B, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Si, and Zn, in both water and soil samples, were measured for quality determination. Selected metals were also analyzed by the enrichment factor (EF), the geoaccumulation index (Igeo), the contamination factor (CF), and the pollution load index (PLI) to evaluate both water and soil ...Более

Tuned CuCr layered double hydroxide/carbon-based nanocomposites inducing sonophotocatalytic degradation of dimethyl phthalate

Mehmet KOBYA

This study is the first to explore the possibility of utilizing CuCr LDH decorated on reduced graphene oxide (rGO) and graphene oxide (GO) as sonophotocatalysts for the degradation of dimethyl phthalate (DMP). CuCr LDH and its nanocomposites were successfully fabricated and characterized. Scanning electron microscopy (SEM) along with high-resolution transmission electron microscope (HRTEM) both evidenced the formation of randomly oriented nanosheet structures of CuCr LDH coupled with thin and folded sheets of GO and rGO. The impact of diverse processes on the degradation efficiency of DMP in t ...Более

Carbon Nanotube Supported CdM(S, Se)/CdTe Anode Catalysts for Electrooxidation of Glucose in Alkaline Media

Hilal DEMİR KIVRAK | Nahit AKTAŞ

The sequential sodium borohydride (SBH, NaBH4) reduction method was utilized to prepare the 0.1 CdSe/CNT, 0.1 CdS/CNT, 0.1 (CdS-CNT)/CdTe, and 0.1 (CdSe-CNT)/CdTe catalysts. The XRD, SEM-EDS, TEM, and XPS analyses were used to characterize the catalysts. The electrochemical measurements were examined by cyclic voltammetry (CV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) analyses for glucose electrooxidation. The characterization analyses revealed that the desired structure was formed on the support material. The electrochemical analysis results indicated that the ...Более

No Evidence of an Elevation Effect Caused by Temperature Differences on Soil Microbial Properties in a Walnut Fruit Forest in Kyrgyzstan

Cıldız ÖSKÖNBAEVA

This study is to investigate the effect of differences in annual average temperature on soil microbial communities as caused by elevation in walnut-fruit forests in Kyrgyzstan with similar vegetation. Soil samples (n 10 per site) were collected from top- and subsoil at three elevation levels (1000, 1300 and 1600 m above sea level) with an average temperature difference of 1.3 °C between sites and analysed for soil chemical and biological properties. All soil properties showed high variability within, but most revealed no differences between elevation levels. Microbial biomass, activity and com ...Более

How social media affecting the mental health of Gen-Z: A mixed method study

The goal of this study was to examine how social media affecting the mental health of Gen-Z. This study uses a systematic search method to identify the effects of social media on mental health. We use previous research articles for this study, the relevant effect of social media on mental health has been discussed and highlights how excessive use of social media is damaging our generation. Social media like Facebook, twitter, Instagram, YouTube etc. were considered for this study. From the studies and analysis, we find that the use of social media has the following effect on mental health on t ...Более