PENERAPAN PEMBELAJARAN KOOPERATIF MODEL GROUP INVESTIGATION (GI) UNTUK MENINGKATKAN MOTIVASI DAN HASIL BELAJAR BIOLOGI

Model pembelajaran mempengaruhi motivasi dan hasil belajar Biologi siswa sekolah menengah atas. Berdasarkan observasi awal, diketahui bahwa pembelajaran Biologi di kelas X-1 SMA Negeri 7 Malang memiliki beberapa ciri, yaitu (1) motivasi belajar siswa cenderung kurang, (2) dalam menyelesaikan suatu tugas, siswa dengan karakteristik yang sama cenderung mengelompok sehingga terbentuk kelompok homogen yang tidak seimbang di kelas, dan (3) metode ceramah yang diterapkan oleh guru tidak menarik minat siswa sehingga mempengaruhi hasil belajarnya. Berdasarkan kondisi tersebut maka dilakukan penelitian dengan menggunakan pembelajaran kooperatif model Group Investigation (GI) untuk meningkatkan motivasi dan hasil belajar Biologi siswa. Jenis penelitian ini adalah penelitian tindakan kelas dengan menggunakan pendekatan kualitatif dan dirancang dalam dua siklus. Hasil penelitian menunjukkan penerapan pembelajaran kooperatif model GI dapat meningkatkan motivasi dan hasil belajar Biologi siswa. Motivasi belajar siswa meningkat sebesar 31, 48% yaitu dari 46, 15% dengan kategori cukup pada siklus I menjadi 77, 63% dengan kategori baik pada siklus II. Hasil belajar siswa juga mengalami peningkatan, terlihat dari nilai rata-rata siswa sebesar 81, 94% pada siklus I menjadi 89, 18% pada siklus II dan siswa yang tuntas belajar juga mengalami peningkatan dari 79, 49% pada siklus I menjadi 97, 44 % pada siklus II. Hasil angket juga menunjukkan bahwa siswa menyukai dan lebih termotivasi untuk belajar Biologi setelah mengikuti pembelajaran dengan pembelajaran kooperatif model GI.

Numerical Study of a Few Problems for Steady and Incompressible Flows of Micropolar Fluids

The present research work is the numerical study of some problems in micropolar fluids flow. The micropolar fluids are viscous fluids having five additional coefficients of viscosity as compared to usual Newtonian fluids. In the micropolar fluid theory, in addition to the usual classical field of velocity, there are two supplementary field variables, the micro-rotation ν (or spin) and the gyration parameter j which have been introduced to elucidate the kinematics of micro-motions. A micropolar fluid contains rotating micro-constituents that cause the fluid to exhibit non-Newtonian behavior. Micropolar fluid model has been found useful in the study of flows of exotic lubricants, colloidal suspensions, polymeric fluids, liquid crystals, additive suspensions, body fluids, turbulent shear flows and flows in capillaries and micro channels. The study investigates the numerical solution of a few problems for steady, laminar and incompressible flow of both the micropolar fluids and Newtonian fluids. The body couples are neglected in case of micropolar fluids flow. The similarity transformations have been used to reduce the governing partial differential equations of motion in to ordinary differential equations. The resulting boundary value problems have been solved by using appropriate numerical techniques. The central differences are applied to these differential equations. The difference equations thus obtained are solved by using Successive Over Relaxation (SOR) method and Simpson’s (1/3) rule. The numerical results have been shown both in tabular as well as in graphical forms. To obtain accuracy of the present numerical results, the computation has been carried out on three different grid sizes. The purpose of this study is to present the numerical solution of different types of flow problems in micropolar fluids as well as in computational fluid dynamics by using appropriate numerical techniques which are straightforward, easy to program and economical. It has been concluded that our numerical scheme works well to solve various flow problems of Newtonian and micropolar fluids. Moreover, the present results of both Newtonian and micropolar fluids are calculated up to six decimal place. The corresponding results of Newtonian fluids for each problem considered have been obtained and presented for comparison purposes.