Titanium Dioxide (TiO2) nanofibers have been prepared using the electrospinning method. This study aims to determine the morphology and crystal structure of the TiO2 nanofibers and to determine the effect of viscosity on the morphology and crystal structure formed. This study used titanium tetraisopropoxide as a precursor, ethanol as a solvent, acetic acid as a solution stabilizer and controlled the hydrolysis reaction of the precursor, and PVP as a fiber-making material. The amount of variations of acetic acid is 2; 2.5; 3; 3.5; and 4 ml respectively. The results of the viscosity test showed that the greater the acetic acid used, the smaller the viscosity. The electrospinning process was carried out at a high voltage of 13 kV with a flow rate of 1.5 ml/hour. The fiber obtained was then calcined at 450 o C for 3 hours. The calcined sample was then analyzed using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). SEM characterization results on samples B, C, and D showed that the sample diameters were 313 ± 28 nm, 275 ± 57 nm, and 242 ± 59 nm, respectively. The results of XRD characterization on sample D showed that the resulting sample had a tetragonal crystal structure with a mixed phase between anatase and rutile. The results of TEM characterization in sample D showed the fiber diameter with a size of 68.05 nm.

This study aims to increase the interest and learning outcomes of class III students through a joint head-numbered learning model on mathematics subjects at North Bekasi Second Elementary School. This type of research uses Classroom Action Research which consists of 2 cycles. Backpack subject 23 students. Data collection techniques consist of observation sheets and essay tests.Based on research, interest in the first cycle obtained an average value of 76.45 with a percentage of 73.91% and the second cycle obtained an average of 86.96 with a percentage of 86.96%. Then, the learning outcomes in the first cycle obtained an average value of 74.18 with a percentage of completeness of 69.57% and the second cycle obtained an average value of 86.96 with a percentage of completeness of 82.61%. This shows that the Numbered Heads Together model can increase the interest and learning outcomes of class III students in Mathematics at North Bekasi Second Elementary School. AbstrakPenelitian ini bertujuan untuk meningkatkan minat dan hasil belajar siswa kelas III melalui model pembelajaran kepala bersama nomor pada mata pelajaran matematika di SDN 2 Bekasi Utara. Jenis penelitian ini menggunakan Penelitian Tindakan Kelas yang terdiri dari 2 siklus. Subjek ransel 23 siswa. Teknik pengumpulan data terdiri dari lembar observasi dan tes esai. Berdasarkan penelitian, minat pada siklus pertama memperoleh nilai rata-rata 76,45 dengan persentase 73,91% dan siklus kedua diperoleh rata-rata 86,96 dengan persentase 86,96%. Kemudian, hasil belajar pada siklus pertama diperoleh nilai rata-rata 74,18 dengan persentase ketuntasan 69,57% dan siklus kedua diperoleh nilai rata-rata 86,96 dengan persentase ketuntasan 82,61%. Ini menunjukkan bahwa model Numbered Heads Together dapat meningkatkan minat dan hasil belajar siswa kelas III Matematika di SD Bekasi Utara II.Kata kunci: minat, hasil belajar matematika, model numbered head together