Nowadays, the necessity of designing proper differentiated tasks for mathematically gifted students is a remarkable subject in international literature and practice. In this design-based study, it was aimed to analyze and construct characteristics for designing differentiated tasks of mathematically gifted students. Through this design process, preliminary and prototyping phases were used as a general framework to reveal these characteristics as design principles of the study. Literature reviews, experiences of practitioners and needs analysis studies about suggestions and key points reflecting the characteristics of differentiated tasks were conducted in preliminary research phase. After this phase, initial form of differentiated tasks with draft design principles were applied in classrooms in try-outs and field test with 12 mathematically gifted students and 4 mathematics teachers of these classrooms. The data obtained through qualitative methods lead to three categories; initial design principles as characteristics obtained through preliminary phase, modifications for tasks, and final design principles as characteristics obtained through prototyping phase.

La 2 (Ni 1-x Co x ) 7 (x = 0.05, 0.1, 0.2) alloys were synthesized directly from sintered mixture of La 2 O 3 + NiO + CoO in the molten CaCl 2 electrolyte by the electro-deoxidation method at 850 • C and the electrochemical hydrogen storage characteristics of the synthesized alloys were observed. Sintering (at 1200 • C for 3 h) converted the hygroscopic La 2 O 3 (by the reaction with NiO) into the non-hygroscopic LaNiO 3 , La 3 Ni 2 O 6.5 and La 4 Ni 3 O 9 depending on the Co content of the oxide mixture. The X-ray diffraction peaks indicated that La 2 NiO 4 was the main La-Ni-O phase formed as a result of partial reduction or dissociation reaction to initiate the LaNi 5 phase formation. The target La 2 Ni 7 phase formed much later than LaNi 5 phase probably due to the sluggish reduction of LaOCl. It was observed that La 2 (Ni 1-x Co x ) 7 (x = 0.05, 0.1, 0.2) alloys had promising discharge capacities changed between 227 mA h g −1 (La 2 (Ni 0.95 Co 0.05 ) 7 ) and 332 mA h g −1 (La 2 (Ni 0.8 Co 0.2 ) 7 ) depending on the alloy Co content. This work clearly indicated that the electro-deoxidation was very effective method in the synthesis of the hydrogen storage materials.The extensive developments in the portable electronic devices and the requirement for the environmental friendly transportation industry withdraw the attention of many researchers on the nickel metal hydride batteries. 1-3 The big portion of the works is conducted on the development of the high performance electrode alloy with the proper synthesis methods for these secondary batteries. 4-9 Recently a novel technique called electro-deoxidation, which is also known as Fray-Farthing-Chen (FFC) Cambridge process, 10,11 is reported as very promising for the economical synthesis of the hydrogen storage alloys. [12][13][14] One of the well-known commercial alloy groups for the nickel metal hydride batteries is lanthanum-nickel based alloys and they are generally synthesized by the melting and casting under the protective atmosphere. [15][16][17][18][19] Of course the individual elements (La, Ni and other additive elements) must be already extracted and refined for the melting and casting processes. The cast products need annealing for several hours to get the structural homogeneity. 20 Obviously this production pathway for the La-Ni based hydrogen storage alloys is not very encouraging especially for the large scale applications like battery systems of the electrical vehicles. The electro-deoxidation method looks more cost-effective since it provides direct synthesis of the alloy with the final stoichiometry from the raw materials (oxides). 21 In this work, as the continuation of our previous work, 22 La 2 (Ni 1-x Co x ) 7 (x = 0.05, 0.1, 0.2) hydrogen storage alloy was synthesized by the molten salt electro-deoxidation method for the first time in the literature. In our previous work we presented the alloy development stages of La 2 Ni 7 during electro-deoxidation. 22 In this work part of Ni was replaced by Co systematically and then the alloy developmen...

The pathogenic gram-positive bacterium Clavibacter michiganensis subsp. michiganensis (Smith) Davis et al. is the most harmful bacterium to tomatoes in many countries with a cooler climate. Multilocus sequence analysis was performed on five housekeeping genes (bipA, gyrB, kdpA, ligA, and sdhA) and three virulence-related genes (ppaA, chpC, and tomA) to determine evolutionary relationships and population structure of 108 C. michiganensis subsp. michiganensis strains collected from Turkey between 1996 and 2012. Based on these analyses, we concluded that C. michiganensis subsp. michiganensis in Turkey is highly uniform. However, at least four novel C. michiganensis subsp. michiganensis strains were recently introduced, possibly at the beginning of the 1990s. The singletons might point to additional sources or to strains that have evolved locally in Turkey.

No abstract

In the scope of the study, augmented reality activities for the fifth-grade mathematics were designed and administrated with students during mathematics lesson. Sixty, fifth grade, students from a middle school in Marmaris -Muğla participated to this study. This study was designed as pretest -posttest experimental research method without control group. An achievement test about fractions was applied as pre-test and post-test to students. In addition, Mathematics attitude scale developed by Aşkar (1986) was also administrated as pre-test and post-test to observe the change in attitudes of students towards mathematics. As a result of the study, it was found that there was a significant difference between the scores of the pre-test and the post-test application of the achievement test. The students' attitudes towards mathematics were also found to be significantly different between pre-test and post-test applications. Moreover, it was also observed that there was no significant difference in gender-based attitudes after the study while the positive attitudes of male students were more favorable than that of girls before the study, and that positive attitudes were balanced among male and female students during this study.