Papers by Keyword: Passive

Abstract: The rail irregularities and wheel-rail interactions in a train running at high speeds may result in large-amplitude vibration in the train's car body and affect passengers by reducing ride comfort. The train suspension systems have a vital role in reducing the vibration and improving ride comfort to an acceptable level. The existing passive viscous dampers have limited scope of achieving this objective. In this paper Magnetorheological (MR) dampers as semi-active control devices for secondary suspension in a railway wagon are used for achieving better ride performance parameters. Compared the ride comfort parameters of the wagon with MR dampers against the conventional passive viscous dampers. The sprung mass acceleration, displacement and suspension travel are assessed for three different control strategies, skyhook, ground hook and hybrid. Matlab/Simulink software is used for simulation of the wagon suspension system.

Abstract: This paper presents a passive wireless multi-parameter sensor system, which is suitable for monitoring the environment in hermetic space like industrial painting room, coal mine, and so on. The system consists of two subsystems: the primary system and the secondary system. The primary system transmits power and receives modulated data through a coupled transformer composed of primary and secondary inductors printed in their subsystems, respectively. The secondary system comprises micro capacitive temperature, pressure and relative humidity sensors and uses a relaxation oscillator to convert capacitance to frequency. Using time division multiplexing unit, it can simultaneously measure multiple sensors. The converted frequency signal is used to vary the amplitude of the waveforms on the coupling inductors. The modulating signal is recovered from the carrier using the envelope detection unit. The measurement results indicate that the pressure, temperature, and relative humidity sensitivities of the passive wireless multi-parameter sensor system are 5.6 fF/hPa, 250fF/°C and 71.4 fF/%RH, respectively. Three sensors linearly response to the change of the environment and the system has good consistency.

Abstract: The need to develop empirical model equations that describe the changes in the nutritional compositions of stored tomatoes under different environmental conditionsA study was carried out to predict and determine the weight and lycopene contents of stored tomatoes. Three sets of four different types of passive evaporative cooling structures made of clay and aluminium were designed and constructed as part of the study. One set consists of four separate cooling chambers. Two cooling chambers were made with aluminium container (cylindrical and square shapes) and the other two were made of clay container (cylindrical and square). These four containers were separately inserted inside a bigger clay pot inter-spaced with clay soil of 5 cm (to form tin-in-pot, pot-in-pot, tin-in-wall and wall-in wall) with the outside structure wrapped with jute sack. The other two sets followed the same pattern with interspacing of 7 cm and 10 cm, respectively. The set with 7 cm interspace served as the control in which the interspace soil and the jute sacks were constantly wetted at intervals of between 2 to 4 hours depending on the rate of evaporation with water at room temperature. The 5 cm and 10 cm interspaced soil were constantly wetted with salt solution (sodium chloride) at the same interval to keep the soil in moist condition. Freshly harvested matured tomatoes (globe variety) were used for the experiments and the temperature and relative humidity inside the cooling chambers were monitored daily . The weight, lycopene contents, bacterial and fungal counts of these produce were determined at intervals of three days for a period of sixteen days. Mathematical models (using essential regression software package) were developed to predict the weight and lycopene contents of the stored produce at various conditions considered in the study. By substituting different values of predictor variables into the model equations, the expected values of weight and lycopene contents of stored tomatoes were predicted. Further analysis was done using a paired sample t-test using SPSS 16.0 computer software package to show the level of significance between the mean of observed and the predicted values for all the models developed. The mathematical models developed are reasonably accurate to predict the storability of fruits and vegetables in passive evaporative cooling structures.

Abstract: The intraocular pressure (IOP) is an indicator for the diagnosis and treatment of glaucoma. The traditional measurement of IOP cannot provide a continuous measurement within 24 hours with compromised functionality in glaucoma diagnosis. This paper presents a wireless, passive and non-invasive contact lens sensor (CLS) for continuous monitoring of IOP based on the flexible substrate. This curvature-sensitive sensor includes an inductor and two capacitors to form a C-L-C resonant circuit, which were embedded in parylene C using PDMS as the intermediate medium layer. The C-L-C resonant circuit is used for passive and wireless sensing and simplifying the wireless bonding step. Compared to parylene C, PDMS has a much lower Young Modulus, enabling the quantification of the sensor curvatures, as an indicator of IOP. To fit human eyeballs, the size of the sensor was designed as follows: the outer diameter: 12 mm, the radius of curvature: 8.5 mm. The sensor was characterized in vitro to obtain the frequency response, and the results show that the sensor has a linearity R>0.97 and a sensitivity>9.7 kHz/kPa. This sensor can be used to monitor IOP together with the reading circuit continuously, enabling the diagnosis of glaucoma without impacting the daily life of users.

Abstract: Building claddings still contains some technologically complicated details. The paper deals with modern diagnostics methods and possible solutions to eliminate energy leak.

Abstract: Collaborative Robots or Cobots are passively assisted devices that are intended to work directly with human operators. We describe a Resizable Cobot that specially designed to expand or retract itself while moving along a specified path. In this paper, we propose and implement a 4-DOF path planning using a path length parameter. The computer simulation using Cobot Kinematic and the experiment result of the Resizable Cobot are provided.

Abstract: Aimed at the disadvantage of traditional magnetic detection such as susceptible to magnetic interference and positioning not accurate, the paper presents an algorithm of passive route detection and localization of armored optical fiber cable based on the pulse induction. By injecting changing current to the detection coil, the algorithm used induction technology to incentive out the induction voltage in metallic materials of the detected armored optical fiber cable and established the model about the distance between them. Then derived that the impact of the armored optical fiber cable on the coil voltage was in reverse proportion to the distance six powers of exponent. In addition , the algorithm used coil array to detect and localize the cable to determine the position of the armored optical fiber cable. The results of the simulation indicates the effectiveness of the presented algorithm and passive route detection system and provides feasible ideas to make the technology of passive route detection of armored optical fiber cable practical on the next step.

Abstract: Wind turbines typically run in harsh environments region, but the general requirements in the case of work unattended. Therefore, the brake system is a key component to protect the safe operation of wind turbines. When the wind turbine over speed occurs, overload or other abnormal conditions, the brake system needs to start immediately, so that the whole unit into the shutdown state to ensure crew safety. This article describes the role of wind turbine brake system, composition, operation principle, comparing the advantages and disadvantages of the most commonly used active and passive spindle brake doubly-fed wind turbine. Completion of a wind turbine import passive brake design, manufacturing localization, combined with wind turbine machine operating parameters, developed analytical test program brakes and the test results, and for the test questions are designed to improve.

Abstract: Energy efficiency must first be a good envelope, then consider saving technology from the device. From the perspective of building life-cycle perspective, the eco-design of energy-efficient throughout, so that the building has good ventilation and shade integrated structure, building envelope insulation effect good, reasonable equipment systems, these measures will be building energy efficiency has played a active role. According to these principles, the program selection, save energy, to obtain better results.

Abstract: This article takes the example of the architectural skin of Wuhan Construction Plaza with the curtain wall reconstructed. By actual thermal performance measurement of architectural skin of the building, datas such as surface temperature of inner and outer skin component, temperature and wind speed between air spaces are obtained for collating and analyzing, the effect of double-skin on thermal performance of building envelope in actual engineering application is studied, and heat insulation of the applied double-skin in the passive energy-efficient design is therefore verified. This article is to provide a reference to the double-skin energy-efficient design in the hot summer area as well as to provide ideas for research and application of passive building energy saving.