Toward A Collective Approach to Course Evaluation in Curriculum Development, Acontemporary Perspective

The purpose of this article was to explore on how course evaluation, decision making process, the methodology of evaluation and various roles of evaluation interact in the process of curriculum development. In the process of this exploration, the characteristics the types of evaluation, purposes of course evaluation, methodology of evaluation, designing of course evaluation instruments and common uses for course evaluation data were highlighted. Finally a critique for course evaluation was done where various researches done on the same were discussed. Keywords: Course Evaluation, Curriculum Developmen

Assessing the influence of the PTTC Principal’s competency in ICT on the teachers’ integration of ICT in teaching Science in PTTCs in Nyanza Region, Kenya.

The study was conducted to assess the influence of Primary Teacher Training College (PTTC) principal’s competency in ICT on the teacher’s integration of ICT in teaching science in PTTC’s in Nyanza region in Kenya. The one research question and one research hypothesis guided the study. The population comprised of 21 principals and 159 tutors. Data from the college principals and tutors was collected by use of interview schedule and a questionnaire. Cronbach alpha reliability computation was done to determine the overall reliability of the instrument. Cronbach alpha coefficient of 0.90 and higher was considered as reliable. The mean, standard deviation and Pearson correlation coefficient was used to analyze the data collected and the hypothesis tested at 0.01 alpha level. The results from the data indicated that the Principal who is competent in Information Communication Technology (ICT) favored the tutor’s ICT integration in teaching science. Results of the hypothesis testing further revealed that there was a significant liner relationship between the principal’s competency in ICT and teacher’s integration of ICT in the teaching of science in PTTC’s. Based on the findings of the study it was recommended that the Kenya government should make it a priority to develop a policy to guide leaders in ICT integration, in teaching science, and Teacher’s Service Commission, Kenya Institute of Curriculum Development, Kenya Education Staff Institute and Ministry of Education and Science Technology should develop packages in ICT integration in teaching science for in servicing Principals prior to appointment. Key words: Competency, ICT Integration, Principal, Information Communication Technolog

Thermally induced diffusion phenomena and compound interlayer structural changes in EUV multilayers

Nanoscale multilayered structures are employed as reflective coatings for short wavelengths in a wide range of analytical and imaging technologies. Thermal stability is vital for their functionality. This thesis addresses the thermally induced internal structural changes in Mo/Si-based and La/B-based multilayers, designed for the extreme ultraviolet wavelength range. The focus of the work is to study the diffusion phenomena and the interactions between nanoscale layers, with particular emphasis on the formation of compound interlayers during thermal loading

Chemical interaction of B4C diffusion barriers with Mo/Si layered nanostructures

B4C barrier layers are added to Mo/Si multilayer structures for EUV optics to enhance thermal stability. However, detailed knowledge about the chemical interaction between B4C and Mo or Si is lacking. The chemical processes during annealing up to 600 °C of a Mo/B4C/Si layered structure were investigated with in-situ hard X-ray XPS and ex-situ depth profiling soft X-ray XPS. A two-stage chemically steered diffusion process was identified. If the diffusion barrier consists of C or B4C, relatively stable intermediate compounds form at the initial stage. The results show that the diffusion barrier functionality of the B4C interlayers is caused by the stability of these compounds

Enhanced thermal stability of extreme ultraviolet multilayers by balancing diffusion-induced structural changes

A multilayer design that compensates period thickness compaction at elevated temperatures is presented. The design is based on a reference multilayer that exhibits compaction upon thermal loading and includes an additional sub-structure, which expands upon thermal loading to compensate for the basic compaction. Using extreme ultraviolet reflecting multilayers as an example, the optimization of the ratio of the number of the expanding Mo/B4C periods to that of compacting B4C-barriered Mo/Si periods is demonstrated. Both the average periodicity and the centroid wavelength of the composite multilayer were preserved during annealing at 250 °C for 60 h

Thermally induced interface chemistry in Mo/B 4C/Si/B 4C multilayered films

B4C diffusion barrier layers are often introduced into Mo/Si multilayered films for enhancement of thermal stability. We observe that such multilayered films exhibit both period expansion and period compaction upon annealing at temperatures below 300 °C, depending on the annealing temperature and time. Using in-situ grazing incidence x-ray reflection measurements during sequential annealing, we resolved picometer periodicity changes in Mo/B4C/Si/B4C, Si/B4C, and Mo/B4C multilayer films, and show that the two opposite period-change effects are a result of interaction of Si with B4C layers, leading to expansion, and MoxSiy formation, leading to compaction. The study of Si/B and Si/C multilayer sub-systems suggests that the cause of expansion is the formation of relatively low density SixBy compounds at the Si-B4C interface. Although the Mo-B4C interface seems to be stable based on reflectometry data, other techniques such as depth profiling x-ray photoelectron spectroscopy and wide angle x-ray diffraction measurements show that Mo and B4C actually intermix

Thermally induced interface chemistry in Mo/B4C/Si/B4C multilayered films

B4C diffusion barrier layers are often introduced into Mo/Si multilayered films for enhancement of thermal stability. We observe that such multilayered films exhibit both period expansion and period compaction upon annealing at temperatures below 300 degrees C, depending on the annealing temperature and time. Using in-situ grazing incidence x-ray reflection measurements during sequential annealing, we resolved picometer periodicity changes in Mo/B4C/Si/B4C, Si/B4C, and Mo/B4C multilayer films, and show that the two opposite period-change effects are a result of interaction of Si with B4C layers, leading to expansion, and MoxSiy formation, leading to compaction. The study of Si/B and Si/C multilayer sub-systems suggests that the cause of expansion is the formation of relatively low density SixBy compounds at the Si-B4C interface. Although the Mo-B4C interface seems to be stable based on reflectometry data, other techniques such as depth profiling x-ray photoelectron spectroscopy and wide angle x-ray diffraction measurements show that Mo and B4C actually intermix. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4751029

Enhanced thermal stability of extreme ultraviolet multilayers by balancing diffusion-induced structural changes

A multilayer design that compensates period thickness compaction at elevated temperatures is presented. The design is based on a reference multilayer that exhibits compaction upon thermal loading and includes an additional sub-structure, which expands upon thermal loading to compensate for the basic compaction. Using extreme ultraviolet reflecting multilayers as an example, the optimization of the ratio of the number of the expanding Mo/B4C periods to that of compacting B4C-barriered Mo/Si periods is demonstrated. Both the average periodicity and the centroid wavelength of the composite multilayer were preserved during annealing at 250 °C for 60 h

Chemical interactions at the interfaces of Mo/B4C/Si/B4C multilayers upon low-temperature annealing

Interactions at interfaces in thin films and multilayers play an important role for present day nano-scaled devices. For example, reducing thermally induced interdiffusion between Mo and Si layers is a key challenge in developing Mo/Si multilayers as reflective coatings for projection lithography and free electron lasers. The introduction of thin B4C barrier layers, intended to reduce thermal damage, results in complex behavior under thermal loads. Using in-situ grazing incidence X-ray reflection measurements during sequential annealing, we resolve picometer changes in the multilayer structure, and link these changes to interactions of Mo and Si with the B4C layers, combined with molybdenum silicide formation with reduced formation rates