The timely detection of human immunodeficiency virus (HIV) at the point of care (POC) can lead to timely medical measures, appropriate treatment, and reducing the growth rate and spread of the disease. In the paper, two HIV-1 biosensors based on a perfect 1-D photonic crystal and a 1-D PC containing a defect layer are proposed to detect the HIV, and the main characteristic parameters of the biosensors, including sensitivity and Q factor, are investigated. Also, the irradiation angle's effect on these two sensors' performance is evaluated. The results declare that the sensitivity of the HIV-1 biosensor based on the perfect photonic crystal is independent of the radiation angle. At the same time, the Q factor of this sensor increases with the increase of the radiation angle, and the value of this quantity under the irradiation angle of 85 degrees is almost 14 times greater than the normal irradiation. On the other hand, the sensitivity and Q factor of the biosensor containing the defect layer is dependent on the irradiation angle, and the maximum values of these quantities, which occur at the radiation angles of 65 and 47 degrees, are equal to 1056 nm/RIU and 12683, respectively. Therefore, this biosensor is suggested as a suitable candidate for HIV detection.

Passive detection and tracking is one of the most important tools in the positioning of hidden targets and controlling their performance and this technology is rapidly expanding. Passive sensors, such as cameras, usually provide azimuth-elevation angle-only data that is not enough to find the target distance and its tracking. Satellite positioning algorithms usually use 3 consecutive angular observations by one sensor or two simultaneous angular observations by two sensors and then predict satellite position by performing an initial estimation of its range. The inaccuracy and presence of noise in the recording of sensor’s angular observations can cause errors in the satellite distance estimating, positioning and tracking. For this purpose, a new method based on least squares estimation technique is proposed in this paper which can provide more accurate satellite ranging and positioning than existing methods using angular azimuth-elevation data from two passive sensors. Simulation results show the applicability of the proposed algorithm in determining the hidden position of the satellites.

One of the key subsystems in satellites is the attitude determination and the sun sensor is one of the most common sensors in this field. Today, due to the increasing development of satellites, the need to increase the accuracy of satellite subsystems seems very necessary. In this paper, the design of a sun sensor made with an optimized slit in the entire field of view are examined. In this sensor, two orthogonal linear detectors are used, on top of each of the detectors, an optimal gap perpendicular to the detectors is required at an optimal distance according to the field of view. Due to the light passing through the optimized slits and its effect on the detectors and the slit, a peak can be seen in the output of the detectors, which according to the location of the peak, the angle of the incoming light can be calculated with high accuracy. The sun sensor made in Shiraz Mechanics Research Institute has an absolute error (2 sigma) of 0.14 in the 50 degrees of field of view.

The purpose of this article is to estimate the position of sound sources. The proposed method uses two acoustic vector sensors in such a way that the intersection of the rays of each acoustic vector sensor (AVS) obtained from their azimuth angle shows the position of a source. Since in practice the sound sources are non-point, then the estimation of the position using this method indicates the area where there is a possibility of the presence of the sound source. In this article, the effect of different parameters on the estimation error of the sound source position is investigated. One of the most important parameters is the rotation angle of the sound source. The obtained results show how the position estimation error changes under what conditions and parameters. This helps to provide the best conditions for estimating the position of the sound source with the least error. The error in position estimation depends on the size of the sound source, the distance of the source to the AVS, the distance of the two sensors from each other, and the angle of the source to the sensors. The proposed method is used in identifying sound sources, especially in military industries and estimating the position of moving sound sources such as road vehicles.

In grain yield monitoring system، the amount of clean grain mass flow rate to the storage bin is the most important yield property. In this research، an impact-plate type grain mass flow sensor was designed، developed and evaluated. After construction of the impact sensor، it was calibrated by loading the impact plate with static weights ranging from 0. 5 to 4. 5 kg every 0. 5 kg and its linear response to the applied loads was proved with a correlation coefficient of 0. 99. Then، grain mass flow measurement tests and data collection were conducted according to the ASABE standard S587، developed for grain mass flow sensors. The tests were conducted in three phases: 1- constant and steady state flow، 2- linear variation of flow، 3- oscillating flow. The results showed that the output of impact plate sensor varies proportionally and linearly with increasing wheat grain (Rowshan cultivar) mass flow rate. The error in prediction of actual flow rate was decreased by increasing the mass flow rate such that the calculated errors at 25%، 50%، 75% and 100% of flow capacity (4. 25 kg s-1) were 8. 3%، 6. 3%، 5. 2% and 4. 9%، respectively. The high coefficient of determination (R2 = 0. 9975) between accumulated mass flow data of impact plate sensor and the reference scale data indicated high accuracy and sensitivity of impact plate sensor in prediction of mass flow variations. The average percent error of impact sensor in variable flow rate in “ramp-up-ramp-down”، “ramp-down-ramp-up” and oscillating flows were 7. 4%، 8. 6% and 8. 3%، respectively.

The purpose of this numerical analysis is to deduce the temperature difference between the two heated wires of the sensor due to an imposed particle velocity. In this research, the effects of sensor geometric parameters such as changing the dimensions of the wires, the distance between the wires and How wires are placed over the sound direction. The sensitivity of sensors is investigated numerically. Numerical studies show that sensitivity is a function of frequency. With frequency increase from 100 to 1000 Hz, it is sharply reduced and then monotonic to zero. Also, been observed that the sensitivity is related to the position of the wires relative to each other and the dimensions of the cross-section of the wires, and sensitivity decreases by increasing the distance between the wires and the height of the cross section of the wires. Further, the sensitivity angle dependence has been investigated, and the observed sensitivity is related to how the wires are placed over the sound wave propagation and in parallel mode by increasing angle from zero to 90 degree, the sensitivity decreases.

This paper presents a study concerning active vibration control of a smart, flexible spacecraft during attitude maneuver using thrusters/ a reaction wheel and piezoelectric patches. The large-angle maneuver and residual vibration of the spacecraft are controlled utilizing an extended Lyapunov-based design (ELD) and strain rate feedback (SRF) theory. The single-axis fully coupled rigid-flexible dynamic of the system is derived applying a Lagrangian approach and Assumed Mode Method (AMM). The system's overall stability, including energetic terms covering a hub, two flexible appendages, PZT sensor/actuator, RW dynamics, and torsional spring, has been proved, and the control law has been derived accordingly. A pulse-width pulse-frequency (PWPF) modulation is used to alleviate the excitations of high-frequency flexible modes. However, due to the fast maneuver, there are still residual vibrations in the system. Hence, the SRF algorithm using PZT is applied to prepare further vibration suppression. The performance of the proposed extended controller is compared to the conventional Lyapunov and pole placement control algorithms. The numerical results for simultaneously large angle attitude and vibration control of a flexible spacecraft through a comparative study verify the merits of the proposed approach.

This paper presents a study concerning active vibration control of a smart flexible spacecraft during attitude maneuver using thrusters and reaction wheels (RW) in combination and piezoelectric (PZT) sensor/actuator patches. The large-angle maneuver and residual vibration of the spacecraft are controlled using an extended Lyapunov-based design (ELD) and strain rate feedback (SRF) theory for a two-mode mission. The single-axis fully coupled nolinear rigid-flexible dynamic of the system is derived applying a Lagrangian approach and Finite Element Method (FEM). The overall stability of the system including energetic terms covering a hub and two flexible appendages, torsional spring, RW, and PZT dynamics, has been proved and the control law has been derived accordingly. A pulse-width pulse-frequency (PWPF) modulation is used to alleviate the excitations of high-frequency flexible modes. However, due to the fast maneuver, there are still residual vibrations in the system. Hence, the SRF algorithm using PZT is applied to prepare further vibration suppression. A great feature of the proposed hybrid actuator system is the switching time of the thrusters and RW, which is based on total system energy. The numerical results for a flexible spacecraft with large-angle, agile, and precise maneuver requirements through a comparative study verify the merits of the proposed approach.

Oil analysis is one of the main methods for monitoring the status of internal combustion engines and oils to ensure the lubricant's protective performance and engine health. This paper investigate oil condition monitoring in gasoline engine using oil dielectric coefficient measurement. At first capacitive sensor pectinate type is designed and manufactured that engine oil can pass through the sensor with high resolution and accuracy for engine monitoring application. Results show that up to 1.5% water pollution in oil, dielectric coefficient and θ is increased linearly. More water pollution increase dielectric coefficient exponentially. Due to investigate oil oxidation in controllable real condition, this sensor and another industrial quality sensor is evaluated in engine durability test. Although oil dielectric coefficient is increased with oil oxidation but also θ is constant permanently. Monitoring the result of dielectric behavior of engine oil in new design sensor is similar to industrial quality sensor. In addition interaction effect of water pollution and oil oxidation is studied. Results indicate that this sensor is capable of detecting water pollution and oxidation in engine oil.

Using proper dimensionless coefficients that are insensitive to various operating conditions is a crucial issue during the utilization of a yawmeter probe. These dimensionless coefficients produce the deviation angle of flow, stagnation and static pressures. In the current study, these coefficients are analyzed using SPM analytical and experimental methods. A comparison of experimental and analytical results shows that SPM analytical method predicts the flow deviation coefficients satisfactorily at the operational angle range of three-hole probe. This method also calculates the stagnation pressure coefficient precisely at the deviation angle range of ±10 degrees. The experimental results show that due to the assumption of constant speed on the probe, the analytical method cannot calculate the static pressure accurately. Experimental observations also demonstrate that velocity is increased and pressure is decreased over the probe. This is due to the suction region at the downstream of probe. Unlike analytical results, experimental observations depict that at zero degrees, the flow static pressure is equal to the average of pressure at the left and the right side of probe. Due to sensitivity of dimensionless coefficients of flow static pressure to variation of Reynolds number, various values are reported at different kinds of literature for these coefficients. These coefficients change with Reynolds number variations and their accuracies are decreased. In the current study, a new proper dimensionless coefficient is introduced which represents minimum sensitivity to Reynolds number.