Optical properties of radially-polarised twisted light

We show that, in general, any type of radially-polarised paraxial twisted optical mode carries only an axial total optical angular momentum (AM) ${\bar {\cal J}_z}=\ell{\cal L}_0$ where $\ell$ is the winding number and ${\cal L}_0$ is a constant. This mode, however, is shown to have zero spin angular momentum (SAM), so it is endowed only with orbital angular momentum (OAM) and no SAM. The helicity is found to be proportional to $\ell$, hence radially-polarised modes display chirality. When applied to a Laguerre-Gaussian (LG) mode our treatment leads to a total helicity equal to $(\ell/|\ell|){\cal Q}$, where ${\cal Q}$ is the action constant. The factor $(\ell/|\ell|)=\pm 1$, depends on the sign, not the magnitude of $\ell$ and so the result holds for any radially-polarised LG mode however large the magnitude of its winding number $\ell$ is. The magnitude of the action constant ${\cal Q}$ and hence the helicity are diminished for all such LG modes of large beam waist $w_0$.Comment: 4 figure

Two Electrons in a Quantum Dot: A Unified Approach

Low-lying energy levels of two interacting electrons confined in a two-dimensional parabolic quantum dot in the presence of an external magnetic field have been revised within the frame of a novel model. The present formalism, which gives closed algebraic solutions for the specific values of magnetic field and spatial confinement length, enables us to see explicitly individual effects of the electron correlation.Comment: 14 page

The effect of creative and critical thinking based laboratory applications on creative and logical thinking abilities of prospective teachers

The purpose of this study was to examine the effect of creative and critical thinking based laboratory method on prospective primary teachers' creative and logical thinking abilities. This research was conducted with 90 prospective elementary school teachers who were enrolled in two classes of education faculty during the spring semester of the 2004-2005 academic year. Creative and critical thinking based laboratory applications were conducted in the experimental group, and traditional laboratory applications were conducted in the control group. As a result of the investigation, it was determined that the experimental group was more successful than the control group in terms of the logical thinking ability and creativity. Implications for science education at the teacher education level were discussed. Copyright (C) 2009 HKIEd APFSLT

The effect of creative and critical thinking based laboratory applications on academic achievement and science process skills

Bu araştırmanın amacı, yaratıcı ve eleştirel düşünme temelli fen laboratuarı uygulamalarının sınıf öğretmeni adaylarının bilimsel süreç becerileri ve akademik başarı düzeylerine etkisini incelemektir. Bu araştırma, 2004-2005 akademik yılının ilkbahar döneminde, eğitim fakültesinin 2 farklı sınıfında bulunan 94 sınıf öğretmeni adayı ile gerçekleştirilmiştir. Deney grubunda, laboratuar uygulamaları, yaratıcı ve eleştirel düşünme temelli yapılırken, kontrol grubunda, geleneksel laboratuar uygulamaları gerçekleştirilmiştir. Bu çalışmanın sonucunda, deney grubundaki öğretmen adaylarının akademik başarı açısından, kontrol grubundaki öğretmen adaylarından anlamlı bir şekilde daha başarılı ve bilimsel süreç becerisi açısından da anlamlı bir şekilde daha gelişmiş oldukları belirlenmiştir. Çalışmadan elde edilen bulgular dikkate alınarak, fen eğitimi açısından, sonuçlar tartışılmıştır.The purpose of the study was to investigate the effect of creative and critical thinking based laboratory method on prospective primary teachers’ science process skills and academic achievement. This research was conducted with 94 prospective elementary teachers who were enrolled in two classes of education faculty in the spring semester of the 2004-2005 academic year. While the creative and critical thinking based laboratory applications were conducted in the experimental group, traditional laboratory applications were conducted in the control group. As a result of the investigation, it was determined that the experimental group was successful than the control group in terms of the science process skills and academic achievement. Implications for science education at the teacher education level were discussed

Köy Enstitüleri ve Lüleburgaz Kepirtepe Köy Enstitüsü tarihi

Ankara : İhsan Doğramacı Bilkent Üniversitesi İktisadi, İdari ve Sosyal Bilimler Fakültesi, Tarih Bölümü, 2014.This work is a student project of the The Department of History, Faculty of Economics, Administrative and Social Sciences, İhsan Doğramacı Bilkent University.by Yiğit, Aslı