Applied Mechanics and Materials Vols. 789-790

Abstract: With the rapid development of the national economy, the use of low-temperature heat in thermal power plant boiler can not be ignored.Although low temperature economizer is widely used in low-temperature waste heat recovery of thermal power plant boiler, the problems of corrosion and fouling are very significant.New type PTFE heat exchanger filled with high thermal conductivity properties can replace the existing metal heat exchanger, fundamentally solve the problems of corrosion and fouling, meet the future development of the thermal power plant, and realize the energy recycling to maximize the benefit of energy.

Abstract: In this paper, a W-band dual-mode substrate integrated cavity fourth-order band-pass filter is presented, which utilizes LTCC technology. The filter is composed of two dual-mode resonators which are constructed by rows of via arrays in the substrate layer. Two coupling vias near particular diagonal corners are set to perturb the two degenerate modes in each cavity and thus to generate an intra-cavity coupling. The filter exhibits 3dB bandwidth about 2.4GHz, return loss better than 19dB and out of band rejection better than 30dB. The filter occupies the area of 3.752mm4.064mm (including the two feeding lines) in the LTCC substrate.

Abstract: This paper presents a novel structure of millimeter-wave amplitude equalization based on low temperature co-fired ceramic (LTCC) technology, which is implemented by substrate integrated waveguide (SIW) resonator, thin film resistor, microstrip-line and metallic via hole probe. It has advantages of compact, easy for integration, low cost, low loss, and mass-producible. The effects of each component for equalizer performance have been analyzed by simulation. In order to validate the new proposed topology, a millimeter-wave gain equalizer is developed and verified by full-wave simulation using 9-layers Ferro A6 substrates. The designed equalizer exhibits excellent performances.

Abstract: The purpose of this paper is to analyze the effect of tube length in calibration instrumentation on dew point measurement of dew point sensors (DPS) and evaluation of measurement uncertainty. When measuring dew point temperature, various tube lengths between dew point generator and dew point sensor (DPS) cause a significant error due to moisture absorption of inner tube. The measurement is carried out to analyze the variation on measured dew point temperature for four cases of tube lengths with 300 mm, 1200 mm, 2500 mm and 5000 mm. The dew point temperature measurements were performed in the range from-60 °C to 10 °C by using calibrated standard chilled mirror hygrometer as reference standard. In order to investigate contribution to the standard uncertainty for the tube length variation as an uncertainty source, expanded uncertainties were evaluated for the cases including the effect of tube length variation as an uncertainty source and excluding it at each measurement point. 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: One of the most common external corrosion failures in petroleum and power industry is due to corrosion under insulation (CUI). The difficulty in corrosion monitoring has contributed to the scarcity of corrosion rate data to be used in Risk-Based Inspection (RBI) analysis for degradation mechanism due to CUI. Limited data for CUI presented in American Petroleum Institute standard, (API 581) reflected some uncertainty for both stainless steels and carbon steels which limits the use of the data for quantitative RBI analysis. The objective of this paper is to present an adaptive neural based fuzzy model to estimate CUI corrosion rate of carbon steel based on the API data. The simulation reveals that the model successfully predict the corrosion rates against the values given by API 581 with a mean absolute deviation ( MAD ) value of 0.0005, within that the model is also providing its outcomes for those values even for which API 581 has not given its results. The results from this model would provide the engineers to do necessary inferences in a more quantitative approach.

Abstract: Automatic programming and process diagnosis are the essential function to drive the Numerical Control (NC) machine tool with probes to measure the products and evaluate the quality of process in every inspection procedure based on on-machine measurement (OMM), especially in the complex parts measuring, which can avoid the products unqualified and promote the efficiency of manufacture and inspection. In this paper, the method of automatic programming, the data exchange of measurement and the principle of process diagnosis are discussed. With a practical case based on FANUC, the effectiveness and efficiency of the method raised in this paper is validated.

Abstract: Infrared earth sensor is one of the key components of satellite attitude measurement system. During the research, infrared earth wave tests signal source to provide power source (hereinafter referred to as Earth-wave signal source. That is involved in the experiment of control system, which contains open, closed, veneer and the whole system to complete the ground testing and calibration of infrared earth sensor. According to the testing requirements of infrared earth sensor, a new test system based on PXI bus is designed. This new test system consists of hardware and software systems, which controls the generation of earth wave signal, completes data acquisition and analysis, and achieves the ground testing calibration. It has advantages including high precision, full function and strong compatibility, which completes calibration of infrared earth sensor ground testing and improves the precision and efficiency.

Abstract: The paper presents the total pressure experimental measurements carried out at the Romanian Research and Development Institute for Gas Turbines COMOTI in order to determine the total pressure losses in the Inter - Turbine Duct of a two spools gas turbine, as a function of the gas turbine operating regime (mass flow rate) and rotational speed. The Inter - Turbine Duct experimental assembly has been designed, manufactured and tested at COMOTI. The total pressures were measured as a function of the pre-swirling angle, which simulates the influence of the high pressure turbine rotational speed located upstream of the Inter turbine duct in the real gas turbine, as well as for three operational regimes, without the pre-swirlers modules. The results indicate that the total pressure loss along the Inter - Turbine Duct is of maximum 0.9 %. The lowest overall total pressure loss occurs at 0o pre-swirling angle, around 0.8%, while along the ITD struts, the lowest pressure loss is obtained for a 15o pre-swirling, below 0.1%. The influence of the operating regime on the total pressure loss was found to be linearly, the pressure loss increasing with the reduced mass flow rate, between 1% and 1.9% overall, and between about 0.1% and 0.4 % along the struts.

Abstract: Recently, the need arises for new machining inprocess techniques to monitor and/or control machining systems. Due to the introduction of digital thermal noncontact cameras, it becomes possible to assess the chip temperature hence, to evaluate the possible relation between edge performance and variation within such temperature. A noncontact infrared thermal camera is mounted on a turning lathe carriage to record the cutting temperatures as cutting speed and feed vary using both coated and uncoated carbide inserts. Temperatures gradient, along with the relevant SEM micrographs, are analyzed for possible correlation with both regular and irregular cutting edge deformation. While cutting speed proved not to be an influential parameter on the depicted temperatures, feed increase tends to lower cutting temperatures. Generally, it is observed that lower heat and temperatures are generated when coated inserts are employed. It is found that cutting temperatures are gradually increased as edge wear and deformation develop.

Abstract: An array of chemiresistors based on conducting polymers was assembled for the differentiation of VCO. The chemiresistor sensors were fabricated through the potentiostatic electrodeposition of polyaniline, polypyrrole and poly (3-methylthiophene) on the gap separating two planar gold electrodes set on a Teflon substrate. The electrical resistance of the sensors were measured and observed to change when exposed to the headspace of oil samples. The sensor response was rapid and exhibited good reversibility and reproducibility. Different signals were obtained for each coconut oil sample and pattern recognition techniques were employed for the analysis of the data. The developed E-nose system was able to discriminate VCO from refined, bleached and deodorized coconut oil (RBDCO) and rancid VCO.