Background: Gas Sensor Array system is a device that mimics the work of how the nose smells using the gas Sensors that could give response toward specific odors. It is used for characterizing the different blended gas that is suited with the biological working nose principle. Thus, it could be used to detect the dental and oral diseases. Periodontitis is one of the diseases caused by the damage on the teeth due to the chronic infection on the gingival structure marked with bacterial plaque and calculus. This study aims to develop an electric nose for odor detection application on the periodontal bacterial biofilm as early detection device for dental and oral disease. Methods: This device is designed as a portable device to ease the data acquisition. The measured data were stored at a database system connected to a real‑ time computer. A gas Array Sensor system with six gas Sensors (TGS 826, TGS 2602, TGS 2600, TGS 2611, TGS 2612, and TGS 2620) has been assembled for the early detection application for dental and oral disease excreted by the bacterial biofilm that caused dental and oral disease, including Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Streptococcus mutans, and Enterococcus faecalis. Results: TGS 826 and TGS 2602 Sensor had the best response showed by the high ADC delta value. Conclusion: GS 826 and TGS 2602 Sensor could be used as a candidate for early detection device for dental and oral disease.

Presently, the conventional methods in, Direction- Finding (DF) are substituted by new Array process-finding algorithms. The new ones are applied on many applications such as, DF, RADAR, SONAR and atc. Although these are able to remove the failures of conventional algorithms, their abilities are affected by some factors such as, noise, unknown parameters of received signals, coupling effects of Array Sensors and many others. On the other hand, Cramer-Rao Bound (CRB) is the minimum obtainable variance of the detection or resolution error. In this paper, it is intended we are intending to extract the positions of Sensors from the CRB so that it goes to minimum value. Also, the results are applied on some Arrays with different shapes (Sensor positions).

In this research a vertical ZnO nanowire Array films synthesized by a low temperature aqueous method. Sensitivity of synthesized films to CO2 and O2 gases in room temperature was considered. XRD and SEM studies show that the film is one dimensional, having harmonized and perpendicular structure. High surface area / volume ratio of vertical ZnO nanowire Array film reveals high sensitivity even in room temperature.

Tomato is the second most important crop in the world, which is often consumed freshly. One of the most importance tomato products is paste that considered being the stuffing ingredient in Iranian foods. Therefore, the safety of tomato paste is so important. The aim of this study was diagnosis adulteration in tomato paste. For this purpose, olfactory machine system based on five gas Sensors (TGS2600, TGS2620, MQ3, TGS880, TGS2610) was constructed and its potential was evaluated in determining the different levels of pumpkin adulteration in tomato paste (0, 5, 10, 15 and 20%). Pure tomato paste detection from adulteration samples was based on the samples smell in the head space and the receipt of smell by Sensors. The principal component analysis (PCA), linear discriminant analysis (LDA), support vector machine (SVM) and partial least squares (PLS) were used to classify and analyze the extracted features of the Sensor response. Results of PCA and PLS indicated that 99 and 94 percent of data variance was covered by two main components. TGS2610 and MQ-3 Sensors and TGS880 Sensor had the highest and lowest application in detection of tomato paste adulteration. The accuracy of the classification by the LDA method was 79. 7%. The polynomial function with accuracy of 77. 78% of the training and 76. 66% validation in the C-SVM method and the radial base function with a precision of 98. 8% of the training and 88. 14% of Validation in the Nu-SVM method had the highest classification accuracy. In total, the olfactory machine system had acceptable performance in separation of different levels of adulteration.

The boundary-layer control authority of a DBD plasma actuator using surface mounted hot-film Sensors is evaluated. Wind tunnel experiments on a wind-turbine blade section were established at a Reynolds number of 0. 27 × 106. Aerodynamic performance of the wind-turbine blade section for both plasma-ON and plasma-OFF modes are evaluated using measurements made by both surface pressure and wake survey behind the model. Two distinct boundary-layer states are recognized. A state which occurs at the onset and in proximity of the deep stall, which is affected by the low-frequency instabilities of the separated flow. In this case, the steady actuation of plasma imparts local momentum on the nearby flow, eliminating the instabilities, hence, reattaching the detached flow. The other state happens beyond the static stall angle of attack of the airfoil where the flow over the suction side of the airfoil is fully separated and coexistence of both the leading edge and the trailing edge shear-layer instabilities and natural trailing edge vortex shedding is the underlying mechanism. In this case, although the plasma actuator eliminates the instabilities, to some extent, but the corresponding momentum injection is not efficient to stabilize and reattach the flow.