SPEKTRA Volume 7 issue 2 contains five papers: 1) Biofilter Manufacture of Azadirachta Indica Leaf Powder and its Effectiveness in Capturing Free Radicals of Cigarette Smoke, 2) Smart Seal Base on Wifi using Web Service PHP, 3) Implementation of TRS-398 Protocol in Routine Calibration of Linac by Determination of Slab Phantom on Water Phantom Correction Factor, 4) Intravenous Infusion Dosing System for Volume Control Based on Signal Periodic Measurement, and 5) Role of Isovector-Isoscalar Coupling on Charge Radius of Heavy and Superheavy Nuclei.