Mental Models of Preservice Science Teachers on the Change in Day Length

anemonThis present study purposed to reveal the mentalmodels of science preservice teachers on the reason for the change in daylength that is related to many disciplines. The study was conducted with 286preservice teachers studying (at grades from 1st to 4th)in the department of science teaching of a university located in Black SeaRegion in Turkey during 2017-2018 academic year. An open-ended question wasasked to the preservice teachers. These answers were evaluated according to thedescriptive analysis and were examined in 3 different models. It was alsoobserved that the number of preservice teachers with a primitive model was thehighest in the first grade, and that the number of preservice teachers with a synthesismodel and a scientific model increased as the grade of education progressed. Onthe basis of the results of the study, it was recommended that it would bebeneficial to create the teaching activities that will enable the preserviceteachers to comprehend the shape and movements of the Earth and the eventscaused by their interaction with the Sun conceptually rather than memorization. Buçalışmada pek çok bilim dalı ile ilişkisi olan gün uzunluğunun değişiminedeniyle ilgili fen bilgisi öğretmen adaylarının zihinsel modellerini ortayaçıkarmak amaçlanmıştır. Çalışma 2017-2018 eğitim-öğretim yılında Türkiye’ninKaradeniz Bölgesi’ndeki bir üniversitenin fen bilgisi öğretmenliği bölümünde öğrenimgörmekte olan (1, 2, 3 ve 4. sınıf) 286 öğretmen adayı ile gerçekleştirilmiştir.Öğretmen adaylarına açık uçlu bir soru yöneltilmiştir. Cevaplar betimselanalize göre değerlendirilerek, 3 farklı modelde incelenmiştir. İlkel modelesahip öğretmen adayının en fazla birinci sınıfta olduğu, sınıf düzeyi artıkçasentez model ve bilimsel modele sahip öğretmen adayı sayısının arttığıgörülmüştür. Çalışma sonuçlarından yola çıkarak Dünya’nın şekli, hareketleri vebunların Güneşle olan etkileşiminin sebep olduğu olayların öğretmen adaylarınaezbere bilgi yerine kavramsal olarak anlamasını sağlayacak öğretimetkinliklerinin yapılmasının yararlı olacağı önerilmiştir. 47138

Hydrogen-bridged chelate ring-assisted pi-stacking interactions

A salicylideneaniline (SA) derivative, (6Z)-6-({[2-(hydroxymethyl)phenyl]amino}methylidene)-3,5-dimethoxycyclohexa-2,4-dien-1-one monohydrate, has an increased aromaticity within its hydrogen-bridged chelate ring owing to its NH character. In the reported crystal structure, nonconventional pi-stacking interactions, which are referred to as hybrid pi-stacking interactions, are observed between a quasiaromatic chelate ring, formed as a result of the resonance-assisted intramolecular hydrogen bond and ordinary aromatic rings. Besides, pi-stacking interactions are also seen between two hydrogen-bridged quasiaromatic chelate rings, which are referred to as pure pi-stacking interactions. A CSD search has revealed that both kinds of interactions are frequently observed in molecular crystals of SA derivatives in fully or partially NH tautomeric form, and aromaticity levels of certain fragments of SA derivatives have dramatic effects on their stacking arrangements. These interactions are distinguished from the usual pi center dot center dot center dot pi interactions by their formation character, i.e. both sigma- and pi-deficient and sigma-deficient character of pure interactions is more pronounced than that of the hybrid ones

Mesomeric effect on the structural and electronic properties of 4-(2-tert-butyl-4-methylphenoxy)phthalonitrile

The molecular and crystal structures of the title compound, C19H18N2O, were determined and characterized by single crystal X-ray diffraction and spectroscopic methods. Details of the molecular geometry imply that there is a mesomeric effect between the electron-withdrawing N atoms of nitrile substituents and electron-donating O atom. Formally, single central O-C-ar bond lengths are considerably different from each other. O-C-ar distance to phthalonitrile ring is shorter than the other O-C-ar distance due to mesomeric effect under discussion. In addition to structural and spectral evidences, possible results from mesomerism of the compound were investigated by topological analysis on the electronic properties using quantum theory of atoms in molecules (QTAIM) approach. It is inferred from topological analysis that the nitrile group in para position has slightly stronger mesomeric effect than that in meta position due to diffusive double charge separation property during meta mesomerism of the compound. Mesomeric effect revealing itself by differences in delocalization indices between certain bonded atom pairs results in considerable decrease in aromaticity of phthalonitrile ring

Conformational analysis and crystal structure of (E)-3-methyl-4-(p-tolyldiazenyl)phenol

The single crystal X-ray diffraction analysis of the title compound, C14H14N2O, reveals that an interesting intermolecular or extended structure (hydrogen-bonded polymeric zigzag chains) is formed by linking its monomer units with O-H center dot center dot center dot N type intermolecular hydrogen bonds. The compound crystallizes in the monoclinic space group P2(1)/n with a 5.8151(5) angstrom, b = 18.106(1) angstrom, c = 11.515(1) angstrom and = 96.891(7)degrees. In order to understand better its structural aspects in solid state, quantum chemical (PM3) calculations were performed on a part of the extended structure of the title compound containing ten monomers. To determine in vacuo conformational flexibility of the compound, molecular energy profile of the title compound was obtained with respect to a selected torsional degree of freedom and the pedal angle varied from -180 degrees to + 180 degrees in every 10 degrees. The results from the computational study suggest that hydrogen-bonding properties in the crystal lattice is fundamental in determining the crystallographically observed conformation of the title compound

Structural and aromatic aspects for tautomerism of (Z)-6-((4-bromophenylamino)methylene)-2,3-dihydroxycyclohexa-2,4-dienone

The molecular and crystal structure of (Z)-6-((4-bromophenylamino)methylene)-2,3-dihydroxycyclohexa- 2,4-dienone were determined by single crystal X-ray diffraction and spectroscopic methods. Molecules of the compound can be regarded as a resonance hybrid of cis-keto tautomer and zwitterionic form. Pairs of molecules of the compound generate pseudocyclic centrosymmetric R-2(2)(10) supramolecular synthons with the aid of O-H center dot center dot center dot O type intermolecular H-bonds. Stacking of R-2(2)(10) synthons along b-axis is stabilized by pi center dot center dot center dot pi interactions. Changes in both covalent topology and molecular geometry of the compound accompanying proton transfer were monitored by a relaxed PES scan with respect to hydroxyl bond length used as redundant internal coordinate. Quantum chemical studies at 6-311 + G(d,p) level reveal that bond lengths which are indicative to tautomerization process cannot reach their expected values even if proton transfer occurs in gas phase and pseudo-aromatic chelate ring formation has primary effect on the stabilization of NH tautomer. Resonance-assisted intramolecular H-bond affects the electronic state of its neighboring aromatic fragments

Synthesis, characterization, and antimicrobial activity of copper(II) complexes with N,N '-propanediyl-bis-benzenesulfonamide and N,N '-ethanediyl-bis-2-methylbenzenesulfonamide

WOS: 000316912800001Copper(II) complexes of new aryldisulfonamides (L (1) = N,N'-bis[(2-methylphenyl)sulfonyl]ethylenediamine) and L (2) = N,N'-propanediyl-bis-benzenesulfonamide with 1,10-phenanthroline have been synthesized and characterized by using elemental analyses, FT-IR, LCMS, conductivity, and magnetic susceptibility techniques. The structures of [Cu(phen)(2)]L-1 (1) and [CuL2(phen)(2)] (2) compounds have been determined. Complex (1) has also been characterized by single crystal X-ray diffraction. The complex (1) crystallizes in the triclinic system, space group P1, with cell constants a = 12.9353(8) , b = 13.8543(9) , c = 14.4513(10) , alpha = 103.593(5)A degrees, beta A = 113.713(5)A degrees, gamma A = 106.104(5)A degrees, and Z = 1. The antibacterial activities of synthesized compounds were studied against Gram-positive bacteria: Staphylococcus aureus, Bacillus subtilis, and B. cereus and Gram-negative bacteria: Escherichia coli, Pseudomonas aeruginosa, and Yersinia enterocolitica by microdilution (as MICs in mu g/mL) and disk diffusion (as diameter zone in mm) method. The biological activity screening showed that (1) has more activity than (2) against the tested bacteria.TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [TBAG 104 T 390]; Gazi University Scientific Research ProjectsGazi University [05/2008-05]The authors wish to thank TUBITAK for the financial support (No: TBAG 104 T 390) and Gazi University Scientific Research Projects (No: 05/2008-05). We would also like to thank TUBITAK for the allocation of time for the NMR, Mass Spectra, and Elemental Analyses

(E)-4-[(4-chlorophenyl)diazenyl]-2-isopropylphenol

In the title compound, C15H15ClN2O, the aromatic rings adopt a trans configuration with respect to the N = N bond, as found for other diazene derivatives. The crystal structure is stabilized by intermolecular O - H center dot center dot center dot N hydrogen bonds, forming a polymeric chain along the c axis

Opinions of Preservice Pre-School Teachers on the Nature of Science

anemonIn this study, it was purposed to determinewhether the opinions of the preservice pre-school teachers on the nature ofscience differentiate according to their grade of education in which theystudy. In the direction of this purpose, the sample of the study composed of164 pre-school preservice teachers studying in the department of pre-schooleducation of a university located in Eastern Anatolia Region. The study wasdesigned in survey model from the descriptive research methods and was cross-sectionallycarried out. Therefore, it was studied with the preservice teachers at 1st, 2nd, 3rd, and 4th grade. 128 of the preserviceteachers are female, and the rest 36 is male. The most general result acquiredform the research is that there is no significant change in the opinions ofpreservice teachers on the nature of science as the grade of educationprogresses. Considering that the pre-school period is a critical andfundamental period for the development of children, it has been recommended toadd course/courses related to the nature of science and teaching science intothe undergraduate program of pre-school education.Buçalışmada okul öncesi öğretmen adaylarının bilimin doğasına yönelikgörüşlerinin öğrenim görülen sınıf seviyesine görefarklılaşıp-farklılaşmadığını belirlemek amaçlanmıştır. Bu amaç doğrultusundaaraştırmanın örneklemini Doğu Anadolu Bölgesi’ndeki bir üniversitenin okulöncesi eğitimi anabilim dalında öğrenim gören 164 okul öncesi öğretmen adayıoluşturmaktadır. Çalışma betimsel araştırma yöntemlerinden tarama modelindetasarlanmış olup, enlemsel olarak yürütülmüştür. Bu sebeple 1, 2, 3 ve 4. sınıföğretmen adayıyla çalışılmıştır. Öğretmen adaylarının 128’i kadın 36’sıerkektir. Elde edilen en genel sonuç; sınıf seviyesi ilerledikçe öğretmenadaylarının bilimin doğasına yönelik görüşlerinde anlamlı değişiklikler meydanagelmediği şeklindedir. Okul öncesi dönemin, çocukların gelişimi için kritik veönemli bir dönem olduğu göz önüne alınarak, okul öncesi eğitimi lisansprogramına bilimin doğası ve öğretimine yönelik ders/dersler eklenmesiönerilmiştir.47141

Desynchronization of pedal motion: Crystallographic and theoretical study of (E)-4-[(4-ethylphenyl)diazenyl]-2-methylphenol

The single crystal X-ray diffraction analysis of the title compound, C15H16N2O, reveals that its molecules exhibit whole-molecule disorder at both crystal lattice sites due to pedal motion in solid state. The compound crystallizes in the monoclinic space group P 2(1)/c with a = 20.5504(14) angstrom, b = 10.8887(5) angstrom, c = 12.0191(8) angstrom and beta = 96.927(5)degrees. While major pedal conformers of the compound in solid state are stabilized by intermolecular O-H center dot center dot center dot N type hydrogen bonds leading to the formation of C(7) chains at Site 1 and C(8) chains at Site 2 along [0 1 0] axis, C-H center dot center dot center dot pi type intermolecular interactions between major and minor conformers also serve to stabilize minor pedal conformers. An interesting feature about the crystal structure is that pedal conformers at Site 1 have two different occupancy factors arising from desynchronization of pedal motion along [2 1 0] direction in crystal phase. Quantum chemical calculations at the B3LYP/6-31++G** level suggest that the desynchronization of pedal motions make more unstable pedal conformers at Site 1 than those at Site 2