
Volume : 27 Issue : 3 Year : 2019


Med J Islamic World Acad Sci: 10 (3)Volume: 10 Issue: 3  1997 

Hide Abstracts  << Back  ORIGINAL ARTICLE 
1.  Effect of Cadmium and Kinetin on Transpiration Rate, Stomatal Opening and Leaf Relative Water Content in Safflower Plants Suzan A. Sayed Pages 73  80
The effects of cadmium and kinetin on transpiration rate, stomatal opening and leaf relative water content were studied in safflower (Carthamus tinctorius) plants. Pollution of the root environment with concentration of cadmium ranging from 3 to 30 M, supplied as CdCI2, reduced leaf area, transpiration rate, stomatal opening and leaf relative water content. Transpiration rates were reduced to 59, 60, 55 and 48% of those in the control plants at 3, 10, 20 and 30 M Cd, respectively. Reduction in transpiration due to higher cadmium contaminators is quite large at noon unlike that in the early morning or late afternoon. Kinetin greatly reduced or reversed the inhibitory effect of cadmium. Kinetintreated plants generally showed a significantly higher transpiration rate, larger stomatal aperture and higher leaf turgidity than those untreated plants. Kinetin also increased leaf area significantly at higher Cd concentration. The highest kinetin concentration used was most effective in this respect. The results proved that cadmium mediated reduction in transpiration rate, stomatal opening and leaf turgidity are effectively reversed by kinetin. 

2.  A Study of The Shielding Properties of Poly Ethylene GlycolLead Oxide Composite Rizwan Hussain, Zea Ul Haq, Din Mohammad Pages 81  84
Finely ground powdered poly ethylene glycol and lead oxide were blended together by physical mixing. Discs of polymermetal oxide composites were prepared using hydraulic press at 200 kN pressure. The gamma ray shielding properties of these materials were determined using a 60Co ray source. The changes in attenuation coefficient (), half value layer (HVL), tenth value layer (TVL) and relaxation length ( ) as a function of lead oxide concentration have been discussed. The results revealed that the shielding properties of poly ethylene glycol increased with the addition of lead oxide. 

3.  Energy Based Method for Determination of Geometrically Non Linear Finite Element K. Ben Amara Pages 85  92
An energy based method is used for the construction of geometrically non linear finite element. A parabolic finite element is constructed as an example to approach continuous arches, mixed structures and semicircle continuous arches. These examples show the advantage of geometrically non linear elements in terms of reducing the number of finite elements for structural analysis. 

4.  Educating Mathematics Teachers Adnan Baki Pages 93  102
In our current teacher education programmes, teachers are being prepared in ways that develop "procedural knowledge of mathematics" which assumes that the teacher is the possessor of ready made mathematical knowledge o be conveyed to the student. On the other hand, "conceptual knowledge of mathematics" challenges the assumption that teachers transmit knowledge to students and argues that teacher's conceptualizations can not be given directly to the learner and that conceptual understanding in mathematics must be constructed by the learner. As a result, much of the constructivist educators in the last decade attempted to provide teachers with ways to organize learning environments, manage instruction, and teach conceptually rather than procedurally and investigated the question of what teachers need to know to teach conceptually, where and how teachers can best acquire and develop that knowledge. This paper addresses each of these questions for Turkish mathematics education and considers some viewpoints which mentioned in the literature. The first section of the paper starts by explaining what is meant by the term "conceptual knowledge of mathematics" which will be used throughout the paper. The second section deals with the current pattern of teacher education and problems in training secondary school mathematics teachers. In the last section, some possible solutions for the shortcomings of the Turkish mathematics education are discussed from a constructive perspective. Finally, the paper will have implications that the effort of teacher education programmes in mathematics should center on a view that the teacher is to enable students to be actively involved in the process of doing mathematics. In particular, teacher's knowledge of mathematics should be promoted and evaluated in terms of mathematics values and concepts not specific skills and symbol manipulations. 



