Zekeriya Doğan

Dr. Zekeriya Doğan

orcid

Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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20 April 2012 in Dalton Transactions
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AŞAbdurrahman Şengül
Abdurrahman Şengül
ZDZekeriya Doğan
Zekeriya Doğan
AAAhmet Altındal
Ahmet Altındal
AÖAli Rıza Özkaya
Ali Rıza Özkaya
BSBekir Salih
Bekir Salih
ÖBÖzer Bekaroğlu
Özer Bekaroğlu
The phthalodinitrile derivative (3) was prepared by the reaction of 4,4′-(octahydro-4,7-methano-5H-inden-5-ylidene)bisphenol (1) and 4-nitrophthalonitrile (2) with dry DMF as the solvent in the presence of the base K2CO3 by the method of nucleophilic substitution of an activated nitro group in an aromatic ring. The template reaction of 3 with the corresponding metal salts gave the novel bi-nuclear ball-type metallophthalocyanines, MPcs {M = Co (4), Cu (5), Zn (6)}. Newly synthesized compounds were characterized by elemental analysis, UV-vis, FT-IR (ATR), MALDI-TOF mass and 1H-NMR spectroscopy techniques. The electronic spectra exhibit an intense π → π* transition of characteristic Q and B bands of the Pc core. The dielectric properties and interface between the spin coated films of 4–6 and a p-type silicon substrate have been studied by fabricating metal–insulator–semiconductor capacitors. The results indicated that the frequency dependence of the dielectric permittivity, ε′(ω), exhibits non-Debye type relaxation for all the temperatures investigated. The ac conductivity results indicated that the conduction mechanism can be explained by a hopping model at low temperatures (<430 K) and a free band conduction mechanism at high temperatures (≥430 K). The density of interface state calculations on these novel compounds showed that the combination of Au/4/p-Si is a promising structure with a high dielectric constant and a low interface trap density suitable for metal-oxide-semiconductor devices. The electrochemical properties of the Pc complexes were examined by cyclic voltammetry, differential voltammetry and controlled potential coulometry on platinum in non-aqueous media. The complexes showed ring-based and/or metal-based mixed-valence behaviours as a result of the remarkable interaction between the two Pc rings and/or metal centres. The mixed-valence splitting values for the complexes suggested that the mixed valence species are considerably stable. The Vulcan XC-72(VC)/Nafion(Nf)/4 modified glassy carbon electrode showed much a higher catalytic performance towards oxygen reduction than those of VC/Nf/5 and VC/Nf/6 modified ones.

30 January 2023 in Processes
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NANergizhan ANAÇ
Nergizhan ANAÇ
ZDZekeriya Doğan
Zekeriya Doğan
The most important advantages of adding additives to adhesives are increasing the bonding strength and reducing the adhesive cost. The desire to reduce costs as well as the need for environmentally friendly and health-friendly products have paved the way for the recycling of waste materials and the use of cheaper natural materials as additives. In this study, mussel, olive pomace, and walnut powders in different ratios (5%, 15%, and 30% by weight) and in different sizes (38 and 45 µm) were added to an epoxy adhesive. The steel materials were joined in the form of single-lap joints by using the obtained adhesives with additives. These joints were subjected to the tensile test and the strengths of these joints were examined. SEM images of the bonding interface were taken, and the distribution of the powders was examined. When the powder size was 45 µm, bond strengths increased in all additive ratios compared to the pure adhesive, while for 38 µm powders, the strength value increased only at the 5% additive ratio. In joints with 45 µm powder additives, the strength increased by up to 38% compared to the pure adhesive, while this rate was determined as 31% for 38 µm.

26 June 2023 in Processes
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NANergizhan ANAÇ
Nergizhan ANAÇ
ZDZekeriya Doğan
Zekeriya Doğan
Abrasive blasting, sometimes known as sandblasting, is a method used to change the surface condition of materials, clean surfaces, and prepare surfaces for applications such as paint, bonding, coating, etc. The abrasive materials used in abrasive blasting are applied to the surface with compressed air or water and vary according to the purpose of application. The abrasive materials used have negative effects on the environment and human health. So far, organic materials have been used in limited applications in abrasive blasting. However, these materials have a high potential of usage since they are environmentally friendly, safe for human health, and have non-toxic and sustainable properties. In this study, the usability of three different organic wastes (walnut shell, olive pomace and mussel shell) recovered by recycling in abrasive blasting was investigated. In addition, the effect of blasting distance (5, 10 and 15 mm), blasting time (10, 20 and 30 s), powder type (mussel shell, olive pomace and walnut shell) and grain size (38, 45 and 63 µm) on surface roughness have been investigated using the Taguchi L9 experimental design. Regression models were built using ANOVA (Analysis of Variance). Moreover, the surface condition after abrasive blasting was examined using an Al2O3 abrasive and compared with other samples. As a result, 5 mm, 30 s, mussel shell and 45 µm test sets were recommended for “larger is better” and it was determined that the blasting time had the greatest effect on the surface roughness by 50.19%. On the other hand, 10 mm, 20 s, walnut shell and 63 µm test sets were recommended for “smaller is better”, and it was determined that blasting time had the greatest effect on the surface roughness by 39.02%. While there was an increase compared to the surface roughness values before abrasive blasting in the first set of experiments, it was determined that the organic material had a polishing rather than an abrasion effect in the second set of experiments.

28 September 2020 in Forensic Science, Medicine and Pathology
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STSadik Toprak
Sadik Toprak
FKFatih Kahrıman
Fatih Kahrıman
ZDZekeriya Doğan
Zekeriya Doğan
GEGokhan Ersoy
Gokhan Ersoy
ECEmine Yilmaz Can
Emine Yilmaz Can
MCMurat Can
Murat Can

5 November 2020 in Forensic Sciences Research
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Journal Article
Open access
STSadik Toprak
Sadik Toprak
ECEmine Yilmaz Can
Emine Yilmaz Can
BABulent Altinsoy
Bulent Altinsoy
JHJohn Hart
John Hart
ZDZekeriya Doğan
Zekeriya Doğan
MÖMustafa Özçetin
Mustafa Özçetin
As social media becomes increasingly ubiquitous, many events are recorded and released on social media platforms, including chemical weapon attacks. We develop an objective tool in order to evaluate brief and unstructured social media videos for analysing sarin exposure from a civilian medical pathology perspective. We developed and validated this new questionnaire using a standardized procedure that includes content domain specification, item pool generation, content validity evaluation, a pilot study, and assessment of reliability and validity. In total, 51 sarin attacks and 48 matched videos were analysed. Cronbach’s α for all 20 items was 0.75, which indicates adequate internal reliability. The test–retest reliability was 0.96, which indicates good internal reliability. The inter-observer intraclass correlation coefficient was 0.97. After verifying sampling adequacy with the Kaiser–Meyer–Olkin measure and the factorability of the items with Barlett’s test of sphericity, a factor analysis was performed. According to the principal axis factoring, a six-factor solution explained 51.86% of the total variance. The receiver-operating characteristic curve analysis showed that the Video Score Questionnaire has a sensitivity of 0.817, a specificity of 0.478, and an efficiency of 65.3. Therefore, the Video Score Questionnaire is reliable and valid for evaluating sarin attacks from brief and unstructured social media videos.

7 May 2011 in Acta Crystallographica Section E Crystallographic Communications
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ZDZekeriya Doğan
Zekeriya Doğan
ASAbdurrahman Sengul
Abdurrahman Sengul
SCSimon Coles
Simon Coles
In the title compound, C(14)H(12)N(2)O(2), the asymmetric unit comprises one half-mol-ecule with an inversion center between the pyridine rings. The rings are trans coplanar with the acetyl groups deviating slightly from the mean planes, making a dihedral angle of 4.63 (4)°. In the crystal, mol-ecules are linked by weak inter-molecular C-H⋯O hydrogen bonds, forming a supra-molecular sheet parallel to (100).