Search

Bu çalışmanın temel amacı, kavram karikatürleri ve eğitsel drama tekniğinin 7. Sınıf öğrencilerinin karışımlar ve saf madde konusundaki başarılarına etkisini incelemektir. Bu araştırmanın çalışma grubunu Diyarbakır'ın Eğil ilçesine bağlı Akalan Köyünde bulunan bir devlet ortaokulunun 7. Sınıfına devam eden 43 öğrenci oluşturmaktadır. Bu araştırmada zayıf deneysel desenlerden biri olan eşitlenmemiş ön test-son test kontrol gruplu desen kullanıldı. Deney grubunda dersler kavram karikatürleriyle zenginleştirilmiş eğitsel drama tekniğiyle işlenirken kontrol grubunda mevcut fen bilimleri öğretim programına göre işlendi. Veri toplama aracı olarak "Saf madde ve karışımlar" konularını içeren 23 soruluk çoktan seçmeli bir başarı testi ön test- son test olarak öğrencilere uygulandı. Ayrıca, deney grubunda yer alan öğrencilerin uygulanan yönteme yönelik görüşlerini belirlemek için öğrenci görüşme formu uygulandı. Çalışmadan elde edilen nicel veriler SPSS paket programı kullanılarak analiz edildi. Öğrenci görüşme formundan elde edilen nitel veriler ise temalar şeklinde çözümlenerek frekans ve yüzdeler şeklinde ifade edildi. Çalışma verilerinin analizi sonucunda, kavram karikatürleriyle zenginleştirilmiş eğitsel drama tekniğine dayalı öğretimin 7. Sınıf öğrencilerinin "saf madde ve karışımlar" konularını anlamalarına katkısı olduğu belirlendi. Ayrıca, öğrencilere uygulanan görüşme formundan elde edilen sonuca göre öğrencilerin bu teknikleri kullanmaktan hoşnut oldukları ve diğer derslerde de kullanmak istedikleri belirlendi. The main purpose of this study is to examine the effects of concept cartoons and educational drama technique on the achievement of 7th grade students in pure substances and mixtures. The study group of this research consists of 43 students attending the 7th grade of a state secondary school in Akalan Village of Eğil district of Diyarbakır. In this study, unequaled pretest-posttest control group design, which is one of the weak experimental designs, was used. While the lessons in the experimental group were taught with the educational drama technique enriched with concept cartoons, the control group was taught according to the existing science curriculum. As a data collection tool a 23-question multiple-choice achievement test covering the subjects of "pure substances and mixtures" was administered to the students as a pre-test and post-test. In addition, a student interview form was used to determine the opinions of the students in the experimental group about the applied method. Quantitative data obtained from the study were analyzed using the SPSS package program. The qualitative data obtained from the student interview form were analyzed as themes and expressed as frequencies and percentages. As a result of the analysis of the study data, it was determined that instruction based on educational drama technique enriched with concept cartoons contributed to the 7th grade students' understanding of "pure substances and mixtures". In addition, according to the results obtained from the interview form applied to the students, it was determined that the students were satisfied with using these techniques and they wanted to use them in other lessons.

Ultra-low-radioactive titanium is the main perspective material for cryostat fabrication in dark matter search experiments. The pathways of the uranium and thorium contamination of Ti sponges produced by the Kroll process were analyzed. The general role of Mg in Ti sponge contamination by U and Th was established. It was found that when transformed to MgCl2 in the Kroll process, Mg was purified from U and Th, and further MgCl2 reduction and sublimation makes it possible to produce low-radioactive Ti sponges.

Special techniques for deep purification of ZnO and WO3 have been developed in this work. A ZnWO4 single crystal has been grown by the Czochralski method using purified ZnO and WO3 chemicals, along with the ZnWO4 crystal-etalon, which has been grown at the same conditions using commercially available 5N ZnO and WO3 chemicals. The actual accidental impurities compositions of both the initial chemicals and the grown crystals have been measured by inductively coupled plasma mass-spectrometry. A complex of comparative spectroscopic studies of the crystals has been performed, including optical absorption spectra, photo-, X-ray-, and cathodoluminescence spectra and decay kinetics, as well as the photoluminescence excitation spectra. The revealed differences in the measured properties of the crystals have been analyzed in terms of influence of the accidental impurities on these properties.

A simple method of synthesis of high pure tris(8-hydroxyquinoline)aluminum (Alq3) from commercial available 5N Al2O3 and 8-hydroxyquinolinol has been developed. One-step exchange chemical reaction has been conducted under controlled 8-hydrixyquinoline vapor at a temperature of 190–240 °C with water removal by phosphorus anhydride. According to analysis of inductively coupled plasma mass-spectrometry, the chemical purity of synthesized Alq3 was 99.998 wt%. Photoluminescence of the synthesized Alq3 has been measured and slightly differed from those of Alq3 obtained by traditional organic synthesis.

Submitted by Pâmela CTC/E (pamela.flegr@uerj.br) on 2021-10-21T17:53:04Z No. of bitstreams: 1 Dissertação - Tania Maria Galo - 2020 - Completa.pdf: 1356335 bytes, checksum: 08cc3ca061f1d345637d21e270b81a19 (MD5) Made available in DSpace on 2021-10-21T17:53:04Z (GMT). No. of bitstreams: 1 Dissertação - Tania Maria Galo - 2020 - Completa.pdf: 1356335 bytes, checksum: 08cc3ca061f1d345637d21e270b81a19 (MD5) Previous issue date: 2020-01-16 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES The description of the precise behavior of thermodynamic properties of pure substances is of great relevance for the evaluation of an Equation of State (EOS) in order to classify to rank with regard to accuracy, predictive power and computational cost. Mota (2019) proposed modifications to the existing parameters in the Patel-Teja equation of state to increase the predictive power of thermodynamic properties of this equation, thus increasing the confidence of this EOS along the saturation region. For this purpose, the accuracy of the modifications of the thermodynamic parameters of the Patel-Teja equation of state proposed by Mota with respect to the modifications made by Forero-Vel ́asquez, the original proposed by Patel-Teja and some results available in the literature are evaluated. The thermodynamic properties investigated are: saturated liquid and vapor volumes, enthalpy, entropy and internal vaporization energy, heat capacity at constant pressure and vapor, velocity of sound and Joule-Thomson coefficient of liquid and vapor of 22 pure polar substances and nonpolar. Based on the results, we can confirm the validity of the new parameters proposed by Mota (2019) for the prediction of thermodynamic properties along the studied region. A descrição do comportamento preciso de propriedades termodinâmicas de substâncias puras é de grande relevância para a avaliação de uma equação de estado (Equation of State, EOS) de maneira a classificá-la quanto a acurácia, poder preditivo e custo computacional. Mota (2019) propôs modificações nos parâmetros existentes na equação de estado de Patel-Teja a fim de aumentar o poder preditivo de propriedades termodinâmicas dessa equação, assim, aumentando a confiança do emprego dessa EOS ao longo da região de saturação. Com esse objetivo, é avaliada aqui a acurácia das modificações dos parâmetros termodinâmicos da equação de estado de Patel-Teja propostas por Mota (2019) com relação as modificações feitas por Forero-Velásquez, a original proposta por Patel-Teja e alguns resultados disponíveis na literatura. As propriedades termodinâmicas investigadas são: volumes de líquido e de vapor saturado, entalpia, entropia e energia interna de vaporização, capacidade calorífica a pressão e vapor constantes, velocidade do som e coeficiente de Joule-Thomson do líquido e do vapor de 22 substâncias puras polares e apolares. Com base nos resultados, pode-se confirmar a validade dos novos parâmetros proposto por Mota (2019) para a predição de propriedades termodinâmicas ao longo da região estudada.

An opportunity to use the laws and mechanisms of preparative gas chromatography to release of monofractions of complex mixtures is shown in the article. Scientific principles and practical development are given for manufacturing nozzle of preparative column, consisting of the stationary phase type Polyethylene glycol adipate-6000 deposited in batches on the solid support section of Chromosorb A. Nozzle is heterogeneous in nature and divided into sections with different dispersion of solid support and a different number of stationary phase on it. Selectivity factor of the column is 1,26±0,04 for this decision. The number of theoretical trays is 482±4.0. Productivity of carvone release is 8,67...9,05 cm3, cariofilen release – 3,46...3,51 cm3 per hour. Purity of released monofractions is 0,94...0,99. The proposed technological solutions preserve native connection, fully meet the requirements of natural products and can be used in any area of production.

An additive method by Le Bas has been adopted to predict the liquid molar volumes at normal boiling points vb for pure substances. Its calculation procedure is reviewed in detail and results obtained are compared with the experimental vb data. It is acknowledged that the additive method can be applied with good performances to predict vb of various substances except small molecules such as acetone, methanol, ethanol and water.

An opportunity to use the laws and mechanisms of preparative gas chromatography to release of monofractions of complex mixtures is shown in the article. Scientific principles and practical development are given for manufacturing nozzle of preparative column, consisting of the stationary phase type Polyethylene glycol adipate-6000 deposited in batches on the solid support section of Chromosorb A.Nozzle is heterogeneous in nature and divided into sections with different dispersion of solid support and a different number of stationary phase on it. Selectivity factor of the column is 1,26±0,04 for this decision. The number of theoretical trays is 482±4.0. Productivity of carvone release is 8,67...9,05 cm3, cariofilen release – 3,46...3,51 cm3 per hour. Purity of released monofractions is 0,94...0,99. The proposed technological solutions preserve native connection, fully meet the requirements of natural products and can be used in any area of production., Для выделения монофракций из смесей сложного состава разработана эффективная насадка препаративной колонки, которая состоит из неподвижной фазы ПЭГ 6000, нанесенной отдельными порциями на секции твердого носителя Хромосорба А. Для минимизации потерь монофракций усовершенствована система улавливания. Оптимизированы параметры препаративной системы, рассчитана производительность и другие технологические показатели., Для виділення монофракцій складних сумішей розроблено ефективну насадку препаративної колонки, яка складається з нерухомої фази ПЕГ 6000, нанесеної окремими порціями на секції твердого носія Хромосорб А. Для мінімізації втрат монофракцій удосконалено систему вловлювання. Оптимізовано параметри препаративної системи, розрахована продуктивність і інші технологічні показники.

具象物をAとし，巨視的概念（自然科学で使われる物質，金属，純物質，混合物，酸，塩基など）をBとする。BはAを包含するが，科学教育では，Bの理解は抽象的だから難しいといわれている。ここで「AならばBである」「AはBではない」などを「記述」とよぶ。本稿では，生徒・学生が一群の「記述」を学習して巨視的概念を形成する方法を明らかにする。授業実践における調査結果は，科学教育における「記述論理」の重要性を強く示唆している。, Let A be an "object" in the real world; and B be a macroscopic concept such as matter, metal, pure substance, mixture, acid, and base in natural science. A implies B, but it is well-known that understanding B is difficult in science education, because B is abstract. Here "A is B", "A is not B" etc are called "descriptions". The present paper deals with a method, by which a class of students learns a list of descriptions to form macroscopic concepts. The examination in an introductory science course suggests that "descriptive logic" plays a very important role in science education.

El presente trabajo centra sus bases en la realidad educativa del país y las dificultades en el aprendizaje de las ciencias naturales que muestran los estudiantes de grado noveno. Se fundamenta conceptualmente en tres marcos; el epistemológico que abarca la construcción histórica que han sufrido los conceptos de sustancia pura y mezcla a lo largo de la historia, el disciplinar donde se presenta el marco teórico actual de los conceptos objeto de esta propuesta y el pedagógico en el cual se presenta el marco referencial del Aprendizaje Cooperativo (AC) como herramienta para la implementación y desarrollo de competencias científicas, así como lo que se entiende en esta propuesta por competencias científicas acorde con los Estándares básicos de competencias en ciencias naturales y ciencias sociales. Finalmente, como anexo se presenta una estrategia didáctica de fácil manejo para cualquier docente interesado en aplicarla. Se incluye: un instrumento diagnóstico, instrucciones, objetivos para cada actividad y finalmente las actividades. Abstract: This paper focuses its bases in the educational reality of the country and the difficulties in learning natural science showing students of 9°. It is based on three conceptual frameworksof concepts in this proposal and teaching, in which the framework is presented of Cooperative Learning (AC) as a tool for the implementation and development of scientific competence and what is meant by this proposal for scientific competence commensurate with the basic standards of competence in natural sciences and social sciences. Finally is annexed a teaching strategy easy to use for any teacher interested in applying. It includes: a diagnostic tool, instructions, objectives for each activity and finally the activities. Maestría

Enthalpy method is commonly used in the simulation of melting and solidification owing to its ease of implementation. It however has a few shortcomings. When it is used to simulate melting)solidification on a coarse grid, the temperature time history of a point close to the interface shows waviness. While simulating melting with natural convection, in order to impose no-slip and impermeability boundary conditions, momentum sink terms are used with some arbitrary constants called mushy zone constants. The values of these are very large and have no physical basis. Further, the chosen values affect the predictions and hence have to be tuned for satisfactory comparison with experimental data. To overcome these deficiencies, a new cell splitting method under the framework of the enthalpy method has been proposed. This method does not produce waviness nor requires mushy zone constants for simulating melting with natural convection. The method is then demonstrated for a simple one-dimensional melting problem and the results are compared with analytical solutions. The method is then demonstrated to work in two-dimensions and comparisons are shown with analytical solutions for problems with planar and curvilinear interfaces. To further benchmark the present method, simulations are performed for melting in a rectangular cavity with natural convection in the liquid melt. The solid-liquid interface obtained is compared satisfactorily with the experimental results available in literature.

In this paper I present an ordered selection of citations from František Wald's publications and correspondence to give some idea of how he fitted in his times, how his views were received by contemporaries, and to illustrate his epistemological views. I highlight the originality of Wald's aim to develop a theory of chemistry on the basis of the concept of 'phase', instead of the concepts of compound and element. In chemistry (including the material sciences) there has been a vast increase in substances that are phases (and not pure compounds), which makes Wald's work still relevant. © 2013 by HYLE and Jaap van Brakel. ispartof: Hyle: An International Journal for the Philosophy of Chemistry vol:19 issue:2 pages:161-183 status: published