Abstract: Paper deals with the applicability of impedance spectroscopy method to testing of cement-based composites prepared from a mix of type CEM I cement and siliceous sand, as well as by substituting 25 % of sand with shredded automobile tires and by adding acrylic polymer binder (10 % w/w of the polymer mass to cement mass). The monitoring of structural changes in the thermal stress is very important, for example for determining the reliability of the whole structure. Samples were intentionally degraded by high-temperature (in a temperature range from 25 °C to 400 °C). The primary monitored magnitudes were electrical capacitance C, the relative permittivity εr and components of electric impedance |Z|.
Based on the Debye theory of dielectric the models were created, their applications and received parameters measured dielectric material is characterized and discussed the uniqueness of determining the values of model parameters. Development of electrical parameters and permittivity at each temperature areas reliably show thus structural changes and thus the structural reliability.
Abstract: The temperature distribution of hot air flow in heating zone of a rectangular duct has been investigated for drying application. The experimental set-up consists of a heater and a fan to generate the hot air flow in the range of temperature from 40 to 100°C and the range of air velocity between 1.20 and 1.57 m/s. An increase of the heater power supply increases the hot air temperature in the heating zone while an increase of air velocity forced by fan decreases the initial temperature at the same power supply provided to generate the hot air flow. The temperature distribution shows that the hot air temperature after transferring through air duct decreases with an increase of the length of the rectangular duct. These results are very important for the air flow temperature and velocity control strategy to apply for heating zone design in the drying process.
Abstract: The purpose of this paper is to study the effect of purging rate on calibration or test of the dew point sensors and estimation of measurement uncertainty. The measurement is carried out to analyze the variation on measured dew point temperatures for the sample dew point sensors (DPS) due to various durations of purge by using calibrated standard chilled mirror hygrometer. To set up measurement condition, the whole measurement system were kept in the state of purging for 3 hours, 15 hours, 65 hours, 140 hours, 200 hours. The dew point temperatures were measured in the range from-50 °C to 10 °C. In order to investigate the effect of purging rate as an uncertainty source on the measurement uncertainty, the contributions to the standard uncertainty for purging rate were also estimated due to reference dew point temperatures. The measurement was conducted according to standard calibration procedure of Korea Testing Laboratory which assures suitability and traceable results. It is also based on international standards.
Abstract: Platinum resistance sensor has the characteristics of large measuring temperature range, high accuracy and stable performance. It is an ideal temperature detecting element, and it is applied widely in industry. This paper designs two kinds of temperature measurement circuits, and expounds the working elements of each kinds of project. We contrast two projects though the follow two factors: the convenience of range regulation and linearization. We choose the better projects. They are provided with applied simply, high precision and low cost.
Abstract: The article presents the results of numerical and experimental investigations concerning contact coordinate measurements of complex ceramic parts made of Al2O3 and ZrO2 based ceramic materials in different states. The investigated parts were manufactured by using two machining processes: ultrasonic assisted grinding and conventional grinding. The results of investigations may be used in order to improve the manufacturing process of geometrically complex ceramic parts.
Abstract: Force sensor based on the six degree of freedom (6-DoF) Stewart platform is universal for wide applications. Mechanism errors are significant for its measuring accuracy. However, because of the multi-variables and the complicated forms, it is difficult to solve the expression directly. The Monte Carlo method is proposed based on the analysis of the system structure and the mathematical model. The effect of mechanism errors on the measurement accuracy was assessed. With this method, a complex accuracy expression of the sensor could be avoided. It also provided a theoretical basis for designing the sensor of the Stewart platform.
Abstract: Sun intensity and angle on efficiency of solar cell System is considered to study. Solar energy is a clean, non-polluting and renewable resource; it uses the photovoltaic effect to convert sunlight into a free and available energy source. However, solar energy output is highly affected by the temperature and intensity of sunlight. As the temperature of the solar module rises, energy output will decrease, if the intensity of sunlight is stronger, there will be more output energy. With adequate heat sink and proper ventilation, a module’s temperature will be decreased, and also increase output energy. This study uses 10 kilowatt grid-connected photovoltaic system and a solar tracker to measure the direction of the sun, to find out the relationship between solar intensity and angle effects on energy output.
Abstract: This work presents an experimental study to monitor the damage propagation of composite material by non destructive testing (NDT) method. In order to achieve this, an open hole condition of glass fiber/epoxy composite has been used as the specimen test under static tensile loading and observed using two different real-time monitoring techniques of NDT namely infra-red (IR) camera and supported by Acoustic Emission. The results show that the thermal response and acoustic emission signals give a good detection on damage appearance and damage propagation of glass fiber/epoxy composite under static tensile loading conditions.
Abstract: The paper presents the results of investigations regarding surface roughness measurements in ultrasonic assisted grinding of selected ZrO2 based ceramic material. There are different results, in the area of surface roughness measurements, presented in the literature. The entry data of hybrid machining process (e.g. grinding wheel type, feed, machining strategy or process variant) may influence these results. The analysis of literature encourages to take up the investigations of surface quality in ultrasonic assisted machining. These investigations may be performed for specific ceramic products and technological tasks which are commonly applied in ceramic machining processes. The knowledge about the machining of ceramic materials in different sintering states is very limited. Based on this finding, ultrasonic assisted and conventional machining processes of ZrO2 based ceramic material in different sintering states were investigated.
Abstract: The force-displacement curves of rat’s red blood cells (RBC) were measured by atomic force microscope (AFM) in this study, and the young’s modulus of RBC were calculated. The different speed and loads of probe on AFM was conducted to exam the effect of young’s modulus in RBC. Furthermore, the relationship between young’s modulus of RBC and different depth of indentation from force-displacement curves were investigated. The experimental results and analysis showed that when probe’s maximum load was 5 nN and the velocity was set for 1, 5, 10 and 20 μm/s, the young’s modulus of normal red blood cells for probe down measurements to AFM were 129.56 ± 42.80, 141.56 ± 31.15, 147.90 ± 24.35 and 149.69 ± 29.27 kPa, respectively. It represented that the young’s modulus of normal red blood cells depended on probe’s velocity. Then when probe’s velocity was 1 μm/s and the load was changed to 1, 5 and 10 nN, the young’s modulus of normal red blood cells were measured for 41.45 ± 22.64, 82.72 ± 53.99 and 202.40 ± 16.01 kPa, respectively. It represented that the young’s modulus of normal red blood cells depended on the probe’s load. On the other side, the results of force-displacement curves exam demonstrated that the deeper of probe indented in cells, the measured young’s modulus of normal red blood cells would be increased more.