Open Access Original Research Article

Closed Loop Control Circuit Design of an Automatic Fire Suppression System

Korkoren Kenneth Cheruiyot

Physical Science International Journal, Page 1-5
DOI: 10.9734/PSIJ/2017/34433

Automatic fire suppression systems control and extinguish fires in buildings without human intervention from widespread use of the techniques of measurements and control. Automatic control is achieved here by a design and implementation process. This system implements an early detection system and communicates it to the inhabitants. The system is designed with the input voltage from the smoke detector sensors, BC107B transistor used as the input, Opto-coupler circuit, an alarm and photoelectric detector. For this case we have voltage divider circuit using a Light Dependent Resistor and potentiometer. This design uses a fan instead of a pump as it uses the same principle to test its performance giving standard resistance, Opto-coupler circuit biasing voltage and resistance of the light dependent resistor. Generally the components used are cost effective and feasible.


Open Access Original Research Article

Open Access Original Research Article

Open Access Original Research Article

Theoretical Study of the Properties of Isatin (1H-indole-2,3-dione) Based Alternating Donor-acceptor Type Conjugated Oligomers

Isaiah, A. Adejoro, Ogunsola, G. Orodepo, Omolara, O. Adeboye, Fredrick, U. Akhigbe

Physical Science International Journal, Page 1-16
DOI: 10.9734/PSIJ/2017/35185

The potential of Isatin (1H-indole-2,3-dione) as a donor moiety in an alternating donor-acceptor conjugated oligomer models was studied. Eight different electron acceptor molecules investigated are: thiazole (Z),thiadiazole (D), thienopyrazine (TP), thienothiadiazole (TD), benzothiadiazole (BT), thiadiazolothienopyrazine (TPD), benzobisthiadiazole (BDD) and thienopyridine (TPY). The geometry and electronic properties of the oligomers were investigated using density functional theory (DFT) method at B3LYP/ 6-31G (d) level. Properties such as torsional angle, bond length and intramolecular charge transfer were analysed. The lowest excitation energies (Eex.) and the maximal absorption wavelength (λabs.) were studied with time-dependent density functional theory (TD-DFT) method. The HOMO-LUMO level and band gap energies were calculated for all the model oligomers. The effect of addition of another isatin moiety to isatin-acceptor type oligomers give rise to D-A-D type structures and the band gap energies was investigated. It was discovered that (ISAT-TPD-ISAT) and (ISAT-BDD-ISAT) have lower band gaps (Eg) of 1.55 and 1.93 eV respectively. This result suggests that the two oligomers could be used as active layer materials in photovoltaic devices.  


Open Access Review Article

Dumpsite Characterisation in Ekpoma from Integrated Surface Geophysical Methods

K. O. Ozegin, O. J. Ataman, S. I. Jegede

Physical Science International Journal, Page 1-11
DOI: 10.9734/PSIJ/2017/35289

Foreseeable consequences of the practice of solid waste disposal in landfills are gas and leachate generation due primarily to microbial decomposition, climatic conditions and refuse characteristics. Hence, this paper presents an assessment of the effects of waste dumpsite using Electromagnetic and electrical resistivity methods in dump located along Police Barrack Road, Ekpoma in Esan West Local Government Area of Edo State. Low Frequency - Electromagnetic (VLF-EM) field data were obtained in four traverses measuring 70 m, 70 m, 40 m and 45 m at profiles 01, 02, 03 and 04 respectively. The VLF-EM data were analysed through qualitative interpretation of the curves and analysed using Karous-Hjelt Software to delineate the conductive and non-conductive zones in the study area. Four Vertical Electrical Sounding (VES) stations were utilized, using Schlumberger configuration. Data obtained from the VES technique were processed using IP2win software. The VES curves obtained revealed simple subsurface geology with characteristic H and A curve types with low resistivities in the range of 37.21 Ωm to 44.9 Ωm indicative of leachate contamination. The VLF technique revealed lithology with high amplitudes in the region of 35 m and 40 to 45 m, 21 to 30 m and 17 to 24 m also indicative of contamination arising from leachate wastes and underground pollution in the dumpsites.