Subtraction Performances of Primary School Prospective Mathematics Teachers Having Different Cognitive Styles *

Abstract Cognitive styles defined as the way by which individuals prefer to use in order to obtain, edit, utilize, remember the information are discussed as the indication of individual differences in many studies. The study aims to investigate behavioral data of mathematics teacher candidates categorized according to their cognitive styles while they perform subtraction operations with small and big numbers. Participants of the study were 30 teacher candidates, 15 of whom have field-dependent cognitive style while 15 of whom have field-independent cognitive style. Obtained data was analyzed in terms of accuracy and reaction time according to the cognitive style. When it was investigated in terms of accuracy, it was found that there was a significant difference between groups according to only small numbers. In terms of reaction type, however, two groups did not differ in terms of both small and big numbers. Moreover, it is seen that field-dependent participants spent more time while they solve subtraction operations with big numbers

1-Amino-2-hydroxy-4-naphthalenesulfonic acid based Schiff bases or naphtho[1,2-d]oxazoles: Selective synthesis and photophysical properties

durmus, sefa/0000-0001-6974-513XWOS: 000352668100008PubMed: 25748593A series of Schiff base and naphtho[1,2-d]oxazole derivatives were selectively synthesized via condensation reaction of 1-amino-2-hydroxy-4-naphthalenesulfonic acid and benzaldehyde derivatives at same conditions. The synthesized compounds were then characterized by using (HNMR)-H-1,(CNMR)-C-13, FTIR spectroscopies and elemental analyses. It was seen that the Schiff bases generated in the presence of OH group at ortho position of benzaldehyde derivatives. However, the products were naphtho[1,2-d]oxazoles in other cases. Then, the synthesized compounds were photophysically investigated by UV absorption and fluorescence emission spectroscopies. As a result, these Schiff bases have shown long wavelength absorption (lambda(max): 386 nm) and emission (lambda(max): 429-437 nm) effect while synthesized naphtho[1,2-d]oxazole derivatives have a set of absorption (lambda(max): about 296, 308, 320 nm) and emission maxima (lambda(max): 378-395 nm) at lower wavelength. (C) 2015 Elsevier B.V. All rights reserved.Duzce University Scientific Research FundDuzce University [2010.05.03.053]This study was financially supported by Duzce University Scientific Research Fund (Project No: 2010.05.03.053). We are grateful to Gaziosmanpasa University Department of Chemistry (Bilal Meral and Huseyin Aksit) for NMR spectra

Ballistic strength of aerated concrete

In regional studies conducted by the Law Enforcement Agency and the Armed Forces within the scope of counter-terrorism activities, to ensure peace and security throughout the country and for the police and military personnel to provide security services, the need to produce different solutions has arisen in the face of attacks on the security points established at many important points, especially at the entrance and exit points of the cities. In this context, by changing the direction and angle of the wall types made of aerated concrete used in construction techniques, 7 variations were tested on these wall types with materials formed with adhesive mortar+plaster, monolithic elastomer polyurea, and non-Newtonian fluid, and the strength of these materials were tested with BR6 and BR7 bullets. The main purpose of this study was to determine the most suitable material in terms of security parameters in the shortest time and at a low cost and to create a reliable structure for security cabins. At the end of the study, the best results were obtained with the shots made on the narrow surface of the aerated concrete and the shots made on the platform formed with non-Newtonian fluid

Synthesis, characterization and electrochemical behavior of some Ni(II), Cu(II), Co(II) and Cd(II) complexes of ONS type tridentate Schiff base ligand

durmus, sefa/0000-0001-6974-513XWOS: 000297450400001PubMed: 21982158Tridentate Schiff base (H2L) ligand was synthesized via condensation of o-hydroxybenzaldehyde and 2-aminothiophenol. The metal complexes were prepared from reaction of the ligand with corresponding metal salts presence of substituted pyridine in two different solvents (MeOH or MeCN). The ligand and metal complexes were then characterized by using FTIR, TGA, H-1 NMR and C-13 NMR spectroscopies. The FTIR spectra showed that H2L was coordinated to the metal ions in tridentate manner with ONS donor sites of the azomethine N, deprotonated phenolic-OH and phenolic-SH. Furthermore, substituted pyridine was coordinated to the central metal atoms. The thermal behavior of the complexes was investigated by using TGA method and dissociations indicated that substituted pyridine and ligand were leaved from coordination. This coordination of the metal complexes was correlated by H-1 NMR and C-13 NMR. Finally, electrochemical behavior of the ligand and a Ni(II) complex were investigated. (C) 2011 Elsevier B.V. All rights reserved.Duzce UniversityDuzce University [2010.05.03.053]The authors wish to thank Duzce University Scientific Research Fund (Project No: 2010.05.03.053) for their support. We are grateful to Ankara University and Sakarya University Department of Chemistry for spectroscopic measurements

Manyetik Spinel-Tipi CoFe2O4 Nanopartiküllerinin Sentezi, Yapısal ve Morfolojik Özelliklerinin İncelenmesi

Spinel-type metal oxide nanoparticles were synthesized via co-precipitation approach. Mono ethylene glycol (MEG) was used as a capping agent to stabilize the particles and prevent them from agglomeration. The structural, morphological and thermal properties of the calcined sample were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), raman spectroscopy and thermal analysis. Energy-dispersive X-ray analysis (EDX) has also proved that the element composition was composed of pure single phase and contained Co, Fe and O elements. The mean crystallite size of the prepared ferrite nanoparticles was determined to be in the range of 30-345 nm based on the SEM images. The magnetic measurements of the CoFe2O4 nanoparticles were examined with a vibrating sample magnetometer (VSM) at room temperature to determine their magnetic behavior and the magnetic parameters were found.Spinel-tipi metal oksit nanopartikülleri birlikte çöktürme yaklaşımı ile sentezlenmiştir. Monoetilen glikol (MEG) parçacıkları stabilize etmek ve aglomerasyonu önlemek için kaplama maddesi olarak kullanılmıştır. Kalsine edilmiş numunenin yapısal, morfolojik ve termal özellikleri, X-ışını kırınımı (XRD), taramalı elektron mikroskobu (SEM), raman spektroskopisi ve termal analiz ile karakterize edilmiştir. Enerji dağılımlı Xışını analizi (EDX), aynı zamanda element bileşiminin, saf tek bir fazdan oluştuğunu ve Co, Fe ve O elementlerini içerdiğini kanıtlamıştır. Hazırlanan ferrit nanoparçacıklarının ortalama parçacık boyutunun, SEM görüntülerine dayanılarak 30-345 nm aralığında olduğu belirlenmiştir. CoFe2O4 nanopartiküllerinin manyetik ölçümleri, manyetik davranışını belirlemek amacıyla oda sıcaklığında titreşimli örnek manyetometre (VSM) ile incelendi ve manyetik parametreleri bulundu

Synthesis of Nano Poly(2-thiophenecarboxaldehyde) and Characterization of Structure

This article describes a chemical oxidative polymerization for the preparation of nano polymeric thiopheneby using FeCl3 as oxidant. 2-thiophenecarboxaldehyde (2-THCA) compound was used as a monomer atthis polymerization process. The structure of synthesized nano polymeric thiophene was confirmed byscanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), thermogravimetricanalysis (TGA), raman spectroscopy, and elemental analysis of C, H, O and S. SEM images showed thatthe poly(2-thiophenecarboxaldehyde) (PTHCA) was synthesized in nanoscale and had a homogeneous andsmooth structure. The size of the synthesized nano particles was not more than 35 nm. Thermal analysis ofnano polymeric thiophene showed that the polymer is thermally stable up to 450-460 oC. When elementalanalysis results of PTHCA were examined, it was seen that the obtained data after the synthesis of nanopolymeric thiophene and the theoretically determined data were agree with each other

Synthesis and Characterization of Dimeric Thio-Schiff Bases by Nano Cerium Oxide and Examination of Their Antimicrobial Activities

In this work, firstly, CeO2 nanoparticles, which can be used as catalysts in many reactions, weresynthesized by preparing aqueous solution of cerium(III) nitrate hexahydrate in basic medium.In the second step, the synthesis of dimeric thio Schiff bases was carried out using two differentmethods. Effect of catalyst on some parameters such as reaction time and yield of product wereinvestigated. The antimicrobial activities of the ligands have been screened in vitro against theorganisms Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae (Gram negativebacteria), Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Bacilluscereus (Gram positive bacteria) and Candida albicans, C. tropicalis, C. guilliermondii, C.glabrata by Disc Diffusion and Microdilution methods. At the same time, antimicrobialactivities of ligands were compared to standard antibiotics (Cefotaxime, Amoxicillin/clavulanicacid, Posacanazole, Nystatin and Gentamicin). Generally, the results obtained in this researchshowed that all tested ligands exhibited more effect towards Gram positive bacteria andCandida species as compared to standard antibiotics

Preparation of Cerium Oxide Nanoparticles: An Efficient Catalyst to the Synthesis of Dimeric Disulphide Schiff Bases

Dimeric disulphide Schiff bases were synthesized via reactions of 2,2’-diaminodiphenyl disulphide with various aromatic aldehydes under reflux and prepared nano?sized cerium oxide as catalyst. It was observed that, when nanocatalyst was used, the catalyst could be reduced the reaction time and increased yields compared with the none-catalyst conditions. Moreover, the CeO2 nanocatalyst was easy preparation, non-hazardous, ecofriendliness and low cost. The morphological features of CeO2 nanocatalyst were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX). The structures of ligands were illuminated some techniques such as fourier transform infrared (FT-IR), nuclear magnetic resonance (NMR) spectroscopy and thermogravimetric analysis (TGA) / differential thermal analysis (DTA

Synthesis and Characterization of Disulfide-Schiff Base Derivatives and in vitro Investigation of Their Antibacterial Activity Against Multidrug-Resistant Acinetobacter baumannii Isolates: A New Study

WOS: 000427630200018In this study two different methods without a catalyst and with a CeO2 nano catalyst were used for the synthesis of dimeric disulfide-Schiff bases. The dimeric disulfide-Schiff base derivatives were characterized by FT-IR, NMR, and MS spectra, and elemental analysis. The disulfide-Schiff bases and their derivatives 2-5c were screened for in vitro antibacterial activity against 40 multidrug-resistant strains of Acinetobacter baumannii, and their minimum inhibitory concentrations were determined. Most of products exhibited high antibacterial activity against Acinetobacter baumannii.Duzce University Scientific Research Fund (BAP) [2014-05-03-259, 2015-05-03-354]This work was supported by the Duzce University Scientific Research Fund (BAP) (projects nos. 2014-05-03-259 and 2015-05-03-354)

Agaricus bisporus Ekstraktı Kullanılarak ZnO Nanopartiküllerinin Yeşil Sentezi: Yapısal Karakterizasyonu ve Biyolojik Aktivitelerinin İncelenmesi

Nanoteknolojinin ilginç yönlerini keşfetmek adına son yıllarda birbirinden farklı birçok çalışma yapılmaktadır. Nanomalzeme üretiminin hızlı gelişimi, çok çeşitli alanlarda metal oksit (ZnO) uygulamalarını da beraberinde getirmiştir. Çinko oksit nanopartikülleri (ZnO NP), ticari kullanım için mekanik veya kimyasal olarak elde edilebilir. Ancak, bu tekniklerin ortaya çıkardığı çevre sorunları bir hayli dikkat çekmiştir. Günümüzde, ZnO NP’nin yeşil sentezi, çevre sorunlarını azaltmayı amaçlayan araştırma alanında özellikle ilgi görmektedir. Bu yeşil yaklaşımda, bitki özü, mikroorganizma, mantar ve alg gibi doğal bazlı malzemeler, biyoaktif fitokimyasallardaki zenginleşmeleri nedeniyle biyo-indirgeyici ve biyo-stabilizatör olarak kullanılmaktadır. Bu çalışmada, ZnO NP farklı çinko tuzları ile doğal bir ürün olan mantar ekstraktı (Agaricus bisporus) kullanılarak sentezlenmiştir. Elde edilen ZnO NP X-ışını kırınımı (XRD), Fourier dönüşümü kızılötesi spektroskopisi (FT-IR), Taramalı elektron mikroskobu (SEM) analizi, Enerji dağılımlı X-ışını analizi (EDX) ile karakterize edildi. Son olarak ZnO NP’nin bakteri ve funguslara karşı antimikrobiyal aktiviteleri kuyu difüzyon yöntemi ile ölçülerek sonuçlar kaydedildi