Second-Phase Induction for Teacher Educators: Challenges and Possibilities

2009 ◽  
pp. 103-113 ◽  
Author(s):  
Åsa Morberg ◽  
Eve Eisenschmidt
Keyword(s):  
Teacher Educators ◽  
Second Phase

Preservice Teachers’ Introduction to Computing

2016 ◽  
Vol 54 (7) ◽  
pp. 997-1021 ◽  
Author(s):  
Ibrahim Cetin
Keyword(s):  
Preservice Teachers ◽  
Teacher Educators ◽  
Attitude Scale ◽  
Visual Programming ◽  
Academic Community ◽  
Second Phase ◽  
Semistructured Interview ◽  
Based Instruction ◽  
K 12 ◽  
Introductory Computing

Computational thinking has been gaining new impetus in the academic community and in K-12 level education. Scratch is a visual programming environment that can be utilized to teach and learn introductory computing concepts. There are some studies investigating the effectiveness of Scratch for K-12 level education. However, studies that have been conducted at the collegiate level, especially in the context of preservice computing teacher education, are very rare. The present study aimed to investigate the effect of Scratch-based instruction on preservice teachers’ understanding of basic programming concepts and their attitudes toward programming. In the present study, a mixed method design was utilized. In the first phase of the study, the data were collected using an achievement test, a practice test, and a computer programming attitude scale. In the second phase of the study, data were collected through a semistructured interview. The results of the study indicated that preservice teachers in Scratch-based instruction had significantly better understanding of basic computing concepts. Qualitative data indicated that Scratch-based instruction was useful in constructing a more meaningful learning environment for preservice teachers. The results of this study have implications for researchers and preservice computing teacher educators when designing an introductory computing course.

scholarly journals Learner Autonomy of Pre-Service Teachers and its Associations with Academic Motivation and Self-Efficacy

2019 ◽  
Vol 16 (Number 2) ◽  
pp. 75-96
Author(s):  
Muhammet Fatih Alkan ◽  
Mehmet Arslan
Keyword(s):  
Self Efficacy ◽  
Academic Motivation ◽  
Teacher Educators ◽  
Learner Autonomy ◽  
Autonomous Learning ◽  
Survey Method ◽  
Second Phase ◽  
School Type ◽  
And Gender ◽  
Academic Self Efficacy

Purpose - Learner autonomy enables an individual to learn how to cope with novelties without getting any help from others. Considering the rapid changes and transformations of the 21st century, it has become essential for teachers to possess this characteristic. Moreover, measuring learner autonomy is required to determine their levels. Thus, the purpose of this two-phased study was to adapt the Autonomous Learning Scale into Turkish and to investigate academic motivation and self-efficacy as the predictors of autonomous learning. Methodology - In the first phase, the Autonomous Learning Scale was adapted into Turkish with the participation of 335 pre-service teachers. In the second phase of the study, the autonomous learning of pre-service teachers was investigated in terms of a number of demographic variables along with academic self-efficacy and academic motivation using the data obtained from 776 pre-service teachers with a survey method. Findings - For the first phase, the confirmatory factor analysis showed that Autonomous Learning Scale was a valid and reliable tool to be used in Turkish samples. For the second phase, the regression analysis revealed that academic self-efficacy and academic motivation were significant predictors of autonomous learning of pre-service teachers. Additionally, their autonomous learning significantly differed in terms of department, high school type, and gender. Furthermore, the GPAs of the pre-service teachers were significantly correlated with their autonomous learning levels. Significance - The Turkish version of the Autonomous Learning Scale was presented to researchers. The relationships between autonomous learning and self-efficacy along with motivation have been asserted in a number of studies. However, the present study not only confirmed the correlations among these variables, but also revealed the predictive powers of these variables on autonomous learning. Therefore, teacher educators and policy makers can gain insights from these findings.

scholarly journals PROMOTING REFLECTIVE PRACTICE VIA THE USE OF 5-STEP COPORA REFLECTIVE MODEL: A CASE STUDY OF EAST MALAYSIAN ESL PRE-SERVICE TEACHERS

2021 ◽  
Vol 32 (1) ◽  
pp. 72
Author(s):  
Wei Ann Ong ◽  
Suyansah Swanto ◽  
Asmaa AlSaqqaf ◽  
Jia Wei Ong
Keyword(s):  
Reflective Practice ◽  
Teacher Educators ◽  
Teaching Practice ◽  
Second Phase ◽  
Focus Group Interviews ◽  
Esl Teachers ◽  
Case Study Design ◽  
Group Interviews ◽  
Structured Approach

Teachers who are reflective are found to be more able to develop themselves professionally. However, pre-service teachers were found to be in need of explicit instructions on reflective practice. This paper presents the results of an investigation on the use of the 5-step Cognition Practice Observation Reflection Action (CoPORA) reflective model among a group of Malaysian ESL pre-service teachers enrolled in an Institute of Teacher Education. A qualitative case study design was utilised, where the model was taught to a group of 13 pre-service ESL teachers who later completed the second phase of their teaching practice. The data for this study comprised the respondents’ entries in their practicum reflection forms, reflective video blogs and focus group interviews. Results showed that respondents have moved from engaging in the lower levels of reflection to a higher pedagogical reflection. They also responded favourably to the use of the 5-step CoPORA reflective model for its structured approach. Nevertheless, the respondents lamented their struggles in rationalising issues faced and in suggesting suitable solutions. It is proposed that the pre-service teachers were shown exemplars of critical reflection to help them see the level at which they ought to reflect. Alternatively, teacher educators can explore a dialogic or collaborative approach to reflection so pre-service teachers can work with one another to further develop their reflective practice.

Grain Refinement in Titanium-Erbium Alloys

1974 ◽  
Vol 32 ◽  
pp. 522-523
Author(s):  
B. B. Rath ◽  
J. E. O'Neal ◽  
R. J. Lederich
Keyword(s):  
Electron Microscopy ◽  
Size Distribution ◽  
Grain Refinement ◽  
Grain Growth ◽  
Volume Fraction ◽  
Pure Titanium ◽  
Systematic Investigation ◽  
Second Phase ◽  
Titanium Matrix ◽  
Average Size

Addition of small amounts of erbium has a profound effect on recrystallization and grain growth in titanium. Erbium, because of its negligible solubility in titanium, precipitates in the titanium matrix as a finely dispersed second phase. The presence of this phase, depending on its average size, distribution, and volume fraction in titanium, strongly inhibits the migration of grain boundaries during recrystallization and grain growth, and thus produces ultimate grains of sub-micrometer dimensions. A systematic investigation has been conducted to study the isothermal grain growth in electrolytically pure titanium and titanium-erbium alloys (Er concentration ranging from 0-0.3 at.%) over the temperature range of 450 to 850°C by electron microscopy.

TEM Studies of Grain Boundary Films in Si3N4 Ceramics

1991 ◽  
Vol 49 ◽  
pp. 930-931
Author(s):  
H.-J. Kleebe ◽  
J.S. Vetrano ◽  
J. Bruley ◽  
M. Rühle
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Silicon Nitride ◽  
Hot Isostatic Pressing ◽  
Amorphous Film ◽  
Liquid Phase Sintering ◽  
Second Phase ◽  
High Temperature Mechanical Properties ◽  
Triple Points ◽  
Boundary Films

It is expected that silicon nitride based ceramics will be used as high-temperature structural components. Though much progress has been made in both processing techniques and microstructural control, the mechanical properties required have not yet been achieved. It is thought that the high-temperature mechanical properties of Si3N4 are limited largely by the secondary glassy phases present at triple points. These are due to various oxide additives used to promote liquid-phase sintering. Therefore, many attempts have been performed to crystallize these second phase glassy pockets in order to improve high temperature properties. In addition to the glassy or crystallized second phases at triple points a thin amorphous film exists at two-grain junctions. This thin film is found even in silicon nitride formed by hot isostatic pressing (HIPing) without additives. It has been proposed by Clarke that an amorphous film can exist at two-grain junctions with an equilibrium thickness.

Polishing process effect on the image of dispersed precipitates

1984 ◽  
Vol 42 ◽  
pp. 534-535
Author(s):  
C.T. Hu ◽  
C.W. Allen
Keyword(s):  
Matrix Material ◽  
Specimen Preparation ◽  
Second Phase ◽  
Precipitate Particle ◽  
Polishing Process ◽  
Second Phase Particles ◽  
The Matrix ◽  
Surface Profiles ◽  
Thinning Process

One important problem in determination of precipitate particle size is the effect of preferential thinning during TEM specimen preparation. Figure 1a schematically represents the original polydispersed Ni3Al precipitates in the Ni rich matrix. The three possible type surface profiles of TEM specimens, which result after electrolytic thinning process are illustrated in Figure 1b. c. & d. These various surface profiles could be produced by using different polishing electrolytes and conditions (i.e. temperature and electric current). The matrix-preferential-etching process causes the matrix material to be attacked much more rapidly than the second phase particles. Figure 1b indicated the result. The nonpreferential and precipitate-preferential-etching results are shown in Figures 1c and 1d respectively.

Structure of second phases in TiAl alloys containing Cr and B

1991 ◽  
Vol 49 ◽  
pp. 576-577
Author(s):  
Ernest L. Hall ◽  
Shyh-Chin Huang
Keyword(s):  
Grain Size ◽  
Second Phase ◽  
Structure And Properties ◽  
Tial Alloys ◽  
Second Phases ◽  
Interstitial Elements

Addition of interstitial elements to γ-TiAl alloys is currently being explored as a method for improving the properties of these alloys. Previous work in which a number of interstitial elements were studied showed that boron was particularly effective in refining the grain size in castings, and led to enhanced strength while maintaining reasonable ductility. Other investigators have shown that B in γ-TiAl alloys tends to promote the formation of TiB2 as a second phase. In this study, the microstructure of Bcontaining TiAl alloys was examined in detail in order to describe the mechanism by which B alters the structure and properties of these alloys.

Microstructural characterization of a rapidly solidified Al-Fe-V-Si alloy for elevated temperature applications

1988 ◽  
Vol 46 ◽  
pp. 550-551
Author(s):  
R. E. Franck ◽  
J. A. Hawk ◽  
G. J. Shiflet
Keyword(s):  
High Temperature ◽  
Elevated Temperature ◽  
Grain Growth ◽  
Volume Fraction ◽  
Microstructural Characterization ◽  
Second Phase ◽  
Microstructural Stability ◽  
Elevated Temperature Strength ◽  
Temperature Applications

Rapid solidification processing (RSP) is one method of producing high strength aluminum alloys for elevated temperature applications. Allied-Signal, Inc. has produced an Al-12.4 Fe-1.2 V-2.3 Si (composition in wt pct) alloy which possesses good microstructural stability up to 425°C. This alloy contains a high volume fraction (37 v/o) of fine nearly spherical, α-Al12(Fe, V)3Si dispersoids. The improved elevated temperature strength and stability of this alloy is due to the slower dispersoid coarsening rate of the silicide particles. Additionally, the high v/o of second phase particles should inhibit recrystallization and grain growth, and thus reduce any loss in strength due to long term, high temperature annealing.The focus of this research is to investigate microstructural changes induced by long term, high temperature static annealing heat-treatments. Annealing treatments for up to 1000 hours were carried out on this alloy at 500°C, 550°C and 600°C. Particle coarsening and/or recrystallization and grain growth would be accelerated in these temperature regimes.

Atomic structure of interface of intermetallic compound TiAl and nitride Ti2AIN using HREM and image processing

1991 ◽  
Vol 49 ◽  
pp. 570-571
Author(s):  
E. Sukedai ◽  
H. Mabuchi ◽  
H. Hashimoto ◽  
Y. Nakayama
Keyword(s):  
Mechanical Properties ◽  
Image Processing ◽  
Composite Material ◽  
Intermetallic Compound ◽  
Side Surface ◽  
High Resolution Electron Microscopy ◽  
Hexagonal Structure ◽  
Second Phase ◽  
Resolution Electron ◽  
Compound Tial

In order to improve the mechanical properties of an intermetal1ic compound TiAl, a composite material of TiAl involving a second phase Ti2AIN was prepared by a new combustion reaction method. It is found that Ti2AIN (hexagonal structure) is a rod shape as shown in Fig.1 and its side surface is almost parallel to the basal plane, and this composite material has distinguished strength at elevated temperature and considerable toughness at room temperature comparing with TiAl single phase material. Since the property of the interface of composite materials has strong influences to their mechanical properties, the structure of the interface of intermetallic compound and nitride on the areas corresponding to 2, 3 and 4 as shown in Fig.1 was investigated using high resolution electron microscopy and image processing.

In Situ microscopy of the anodic etching of silicon

1995 ◽  
Vol 53 ◽  
pp. 232-233
Author(s):  
Frances M. Ross ◽  
Peter C. Searson
Keyword(s):  
Composite Structures ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Selective Etching ◽  
Silicon On Insulator ◽  
Second Phase ◽  
Porous Layers ◽  
New Class ◽  
Porous Semiconductors

Porous semiconductors represent a relatively new class of materials formed by the selective etching of a single or polycrystalline substrate. Although porous silicon has received considerable attention due to its novel optical properties1, porous layers can be formed in other semiconductors such as GaAs and GaP. These materials are characterised by very high surface area and by electrical, optical and chemical properties that may differ considerably from bulk. The properties depend on the pore morphology, which can be controlled by adjusting the processing conditions and the dopant concentration. A number of novel structures can be fabricated using selective etching. For example, self-supporting membranes can be made by growing pores through a wafer, films with modulated pore structure can be fabricated by varying the applied potential during growth, composite structures can be prepared by depositing a second phase into the pores and silicon-on-insulator structures can be formed by oxidising a buried porous layer. In all these applications the ability to grow nanostructures controllably is critical.

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