Polychlorinated biphenyls (PCBs) are important class of persist organic pollutants that were used as a component of paints especially in printings, as plastificator of plastics and insulating materials in transformers and capacitors, heat transfer fluids, additives in hydraulic fluids in vacuum and turbine pumps. There is always a need to establish reliable procedures for predicting the bioconcentration potential of chemicals from the knowledge of their molecular structure, or from readily measurable properties of the substance. Hence, correlation and prediction of biococentration factors (BCFs) based on λ_max and vibration frequencies of various bonds viz υ(C-H) and υ(C=C) of biphenyl and its fifty-seven derivatives have been made. For the study, the molecular modeling and geometry optimization of the PCBs have been performed on workspace program of CAChe Pro 5.04 software of Fujitsu using DFT method. UV-visible spectra for each compound were created by electron transition between molecular orbitals as electromagnetic radiation in the visible and ultraviolet (UV-visible) region is absorbed by the molecule. The energies of excited electronic states were computed quantum mechanically. IR spectra of transitions for each compound were created by coordinated motions of the atoms as electromagnetic radiation in the infrared region is absorbed by the molecule. The force necessary to distort the molecule was computed quantum mechanically from its equilibrium geometry and thus frequency of vibrational transitions was predicted. Project Leader Program associated with CAChe has been used for multiple linear regression (MLR) analysis using above spectroscopic data as independent variables and BCFs of PCBs as dependent variables. The reliability of correlation and predicting ability of the MLR equations (models) are judged by R², R²_adj, se, q²_L10O and F values. This study reflected clearly that UV and IR spectroscopic data can be used to predict BCFs of a large number of related compounds within limited time without any difficulty.

This research work is about the propagation of electromagnetic waves on coaxial cables such that its resistive losses are minimized, and signal quality is improved. The resistive loss of a coaxial cable is caused by several things; impedance of the conductor, and the type of dielectric material used and the skin effect and causes the signal to be attenuated. In this research, various comparison was made on different coaxial cables in other to test their resistivity per length of the conductor and measure the losses per meter of the coaxial cables. The various properties of the conductor, the impedance, capacitance, and the velocity of propagations was taken into consideration. Measurements were carried out to derive our data, and MATLAB was used in analyzing the results and the behaviour of the LMR series, RG8, RG6A, Davis RF, and CQ110 coaxial cables. Based on the findings, it is concluded that for a better and improved signal quality and to reduce resistive losses in coaxial cables, the characteristic impedance of the cable should be 80 ohms as this will reduce the coaxial cable resistive losses.