- Eklemek veya çıkarmak istediğiniz kriterleriniz için 'Dahil' / 'Hariç' seçeneğini kullanabilirsiniz. Sorgu satırları birbirine 'VE' bağlacı ile bağlıdır. - İptal tuşuna basarak normal aramaya dönebilirsiniz.
A series of novel orthopedic calcium phosphate (CaP+CaCO3) cements have been developed. The common point in these cements was that they all utilized single-phase CaCO3 (calcite or vaterite) in their powder components. The major phase in the end-product of these cements was carbonated, Ca-deficient, apatitic calcium phosphate, together with some varying amounts of unreacted CaCO3. Calcite powders used were needle-like or acicular in shape, whereas the vaterite powders were monodisperse, and spherical or ellipsoidal in shape. A new method for synthesizing spheroidal vaterite powders has also been developed. Setting solutions for calci . . .te-based cement scaffolds were prepared by acid-base neutralization of concentrated H3PO 4 and NaOH. 0.5 M phosphate buffer solution was used to transform precipitated vaterite powders into CaP at 37° to 70°C. Setting solutions possessed pH values ranging from 3 to 7.4 at room temperature. Resultant cements were micro- (5 to 50 micron pores) and macroporous (200 to 700 micron pores). In the macroporous cements, total porosity was variable from 20 to 45%. Setting times of those cements were adjustable over the range of 12 to 25 minutes. Compressive strengths of these cements varied from 2 to 3 MPa, depending on their porosity. CaP+CaCO3 cements thus obtained had relatively high surface areas (30 to 85 m2/g) whose surfaces were covered with nanocrystallites similar in size to the nanoplatelets found in biological collagen-calcium phosphate composites. Cement scaffolds were characterized by XRD, FTIR, SEM, ICP-AES, surface area and compressive strength measurements
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The main goal of this thesis is to investigate the effect of two vocabulary learning approaches: 1) Computer-assisted Language Learning (CALL) with a computer-based flashcards program, Quizlet, 2) Keeping vocabulary notebooks on high school EFL learners' vocabulary learning. The vocabulary targeted for the study is determined from three sequential units of the textbook. The units are determined randomly considering the starting date of the study. Eighty-nine students in four beginner EFL classes were randomly assigned as control or treatment groups. A computer-based flashcard program (Quizlet) and a vocabulary notebook program was i . . .mplemented in two different classes over a 3 week period. The remaining two classes acting as control groups followed the same curriculum with the same materials without using Quizlet or keeping vocabulary notebooks. Vocabulary acquisition was measured by pre, post and delayed post-tests of unannounced vocabulary tests including orthography, grammatical accuracy and use adapted from [1] Laufer & Goldstein (2004) and, meaning and form, adapted from [2] Webb (2009). Pre, post and delayed post-test scores of students were analyzed to evaluate the effectiveness of the learning process. Learners' perceptions about the training are also investigated by means of interviews. The results show that participants who learned the target words through Quizlet Flashcard Software Program outperformed those who completed the tasks by means of vocabulary notebook and control group. The analysis of the differences between the two tasks (receptive and productive) for each aspect (orthography, meaning and form, grammar) shows that the tasks measuring receptive knowledge led to significantly higher gains than tasks measuring productive knowledge of all three groups
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The effectiveness of instructional design for developing listening comprehension in English as a second language (L2) is of prime concern to language teachers. Several technology based instructional designs with the emphasis on distinct presentation of listening tasks are highlighted in literature. However, there are a lack of empirical studies to clarify issues concerning modality differences for foreign language (FL) learners and their effect on comprehension. Moreover, learners' listening performance may be affected by the modality in which the tasks are presented (extraneous cognitive load) or the amount of cognitive resources t . . .hat learners invest in schema construction and automation (germane cognitive load). Based on cognitive load theory, this study examines whether the subjects' listening performance varied when the instructional formats of listening tasks were presented in three different modalities. Listening with auditory materials only (LO), narrow listening (NL), listening with a full written script (LFS) were employed to evaluate the subjects' listening performance. This study employs a mixed method design utilizing qualitative and quantitative tools including semi-structured interviews with test takers to assess the best facilitating modality for listening comprehension as well as post test scores to determine student performance. Two hundred and eight, intermediate and advanced level pre-service teacher candidates of English whose L1 was Turkish completed four tests through different representations that required them to listen to dialogues and to complete a number of multiple choice comprehension questions
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The aim of this study is to investigate the eye movement and pencil usage differences between symbolic representation of a question and context design in a passage. For this purpose, an experimental study in which forty-one students' eye movements were recorded by an eye-tracker and their answers to fourteen GRE (Graduate Record Examination) questions were collected via an online assessment tool. Questions were asked through the browser and participants' digital pen usage (mouse click counts) was recorded by graphic tablet via the software. Twenty-one participants took the Test-1 (four symbolic, three text passages) and the remainin . . .g twenty took the Test-2 (four symbolic, three text passages) which consisted of the same questions asked in a different presentation modality. Which participants would take the tests first was determined randomly. Tests were used in a counterbalanced design and the sequence of the questions were randomly aligned in order to eliminate the primary effect. Paired sample t-tests and Wilcoxon signed rank tests were applied on eye-metrics for the comparison of the presentation modalities. The results showed that designing a question without any context (using the equations) caused a decrease on eye movements and pencil usage. However, it caused an increase on the fixation duration. On the contrary, using symbols in a question context did not effect on students' fixation duration and pencil usage. Asking a logical reasoning question in a different context with the same number of words does not effect on students' pencil usage and eye movements
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6698 sayılı Kişisel Verilerin Korunması Kanunu kapsamında yükümlülüklerimiz ve çerez politikamız hakkında bilgi sahibi olmak için alttaki bağlantıyı kullanabilirsiniz.
