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Cardiovascular diseases (CVDs) have been the leading threat to human life. An effective way for sensitive and accurate CVD diagnosis is to measure the biochemical markers released from the damaged myocardial cells in the bloodstream. Here, a multi-analyte, fluorophore mediated, fiber-optic immuno-biosensing system is being developed to simultaneously and rapidly quantify four clinically important cardiac markers, myoglobin, C-reactive protein, cardiac troponin I, and B-type natriuretic peptide. To quantify these markers at a pico-molar level, novel nanoparticle reagents enhancing fluorescence were used and signal enhancement was obtained as high as approximately 230%. Micro-electro-mechanical system (MEMS) was integrated to this system to ensure a reliable and fully-automated sensing performance. A point-of-care, automatic microfluidic sensing system for four cardiac marker quantification was developed with the properties of 3 cm sensor size, 300 microL sample volume, 9-minute assay time, and an average signal-to-noise ratio of 35.

The storage and reduction features of a family of Pt/Rh/BaO/CeO2/Al2O3 washcoated monolith catalysts are compared in terms of NO x conversion and product selectivity using H2 as the reductant. The catalyst composition, monolith temperature, regeneration time, and presence of H2O and CO2 in the feed were systematically varied to identify trends and to elucidate effects. In addition to cycling, experiments involving the reduction of a fixed amount of prestored NO x help to isolate differences in the regeneration features of the catalysts. The addition of both CeO2 and Rh to Pt/BaO increases the cycle-averaged NO x conversion and selectivity to N2, but oxygen storage on the ceria expectedly leads to the consumption of additional reductant during the regeneration. CeO2 is shown to be an inferior NO x storage component, but as a supplement to BaO, CeO2 provides the role of promoting the oxidation of NH3 to N2. The same stored oxygen is the likely cause for the enhanced NH3 oxidation. On the other hand, Pt/BaO is shown to be the most effective catalyst for converting NO x to NH3. Fixed NO x storage experiments show the existence of at least three rate-controlling regimes: one that is reductant-feed-rate-limited, another that is limited by NO x storage phase diffusion, and a third that has a chemical or textural origin. On Pt/BaO, the first two regimes are clearly distinguishable, whereas a more complex picture emerges for Pt/CeO2, with which a fraction of the stored NO x is kinetically inaccessible to reduction. Water inhibits the oxidation of NO on each catalyst, but the cycle-averaged NO x conversion is largely unaffected. In contrast, CO2 has only a minor effect on the conversion during steady state NO oxidation but significantly inhibits the NO x conversion during cyclic storage and reduction. This effect is attributed to the known higher stability of BaCO3 compared with BaO/Ba(OH)2. The conversion of H2 to the less effective reductant CO via reverse water gas shift chemistry is a contributing factor based on steady-state activity tests. This pathway is shown to be most important for the catalysts, containing Rh/CeO2, a known effective water gas shift catalyst. Building on the existing literature, most of the observed trends are interpreted in terms of the likely reaction pathways and transport processes. The findings are assessed in terms of identifying the catalyst best suited to the specific NO x trap application, be it a stand-alone reactor or one coupled with downstream NH3-based selective catalytic reduction.

A system composed of laser sensor and 6-DOF industrial robot is proposed to obtain complete three-dimensional (3-D) information of the object surface. Suitable for the different combining ways of laser sensor and robot, a new method to calibrate the position and pose between sensor and robot is presented. By using a standard sphere with known radius as a reference tool, the rotation and translation matrices between the laser sensor and robot are computed, respectively in two steps, so that many unstable factors introduced in conventional optimization methods can be avoided. The experimental results show that the accuracy of the proposed calibration method can be achieved up to 0.062 mm. The calibration method is also implemented into the automated robot scanning system to reconstruct a car door panel.

A vision-based robot self-calibration method is proposed in this paper to evaluate the kinematic parameter errors of a robot using a visual sensor mounted on its end-effector. This approach could be performed in the industrial field without external, expensive apparatus or an elaborate setup. A robot Tool Center Point (TCP) is defined in the structural model of a line-structured laser sensor, and aligned to a reference point fixed in the robot workspace. A mathematical model is established to formulate the misalignment errors with kinematic parameter errors and TCP position errors. Based on the fixed point constraints, the kinematic parameter errors and TCP position errors are identified with an iterative algorithm. Compared to the conventional methods, this proposed method eliminates the need for a robot-based-frame and hand-to-eye calibrations, shortens the error propagation chain, and makes the calibration process more accurate and convenient. A validation experiment is performed on an ABB IRB2400 robot. An optimal configuration on the number and distribution of fixed points in the robot workspace is obtained based on the experimental results. Comparative experiments reveal that there is a significant improvement of the measuring accuracy of the robotic visual inspection system.

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A prototype of a fiber-optic, multi-analyte, immunobiosensing system was developed to simultaneously quantify disease-representing biomarkers in blood plasma. This system was for simultaneous quantification of two different groups of multi-biomarkers related to cardiovascular diseases (CVD): anticoagulants (protein C, protein S, antithrombin III, and plasminogen) for deficiency diagnosis; and cardiac markers (B-type natriuretic peptide, cardiac troponin I, myoglobin, and C-reactive protein) for coronary heart disease diagnosis. As an initial effort towards the development of a disposable and easy-to-use sensing cartridge as a rapid diagnostic tool for CVD related diseases, a prototype of a flow control system was also developed to automatically perform simultaneous four-analyte quantification. Currently, the system is capable of quantifying the multiple anticoagulants in their clinically significant sensing ranges within 5 minutes, at an average signal-to-noise (S/N) ratio of 25. A simultaneous assay of the four cardiac markers can be performed within 10 min, at an average S/N ratio of 20. When this highly portable multi-analyte sensing system is completed and successfully tested for CVD patient's plasma, it can provide rapid (<10 min) and reliable diagnostic and prognostic information at a patient's bedside.

A laboratory test was conducted to investigate the effect of the freeze-thaw action of liquid nitrogen on the pore structure and permeability of coal rock. First, coal rock samples with similar sound velocities and permeabilities were selected. These samples were prepared in different water saturation levels and subjected to nuclear magnetic resonance (NMR) test before and after the freeze-thaw action. Furthermore, the freeze-thaw cycle of liquid nitrogen, freezing time, and water saturation of coal rocks were controlled in permeability test. Results showed that the pore diameter, porosity, and permeability of the coal rocks increase after the freeze-thaw action of liquid nitrogen. These characteristics increase further with the increase of water saturation. The fracturing mechanisms of the freeze-thaw action of liquid nitrogen were summarized in two aspects, phase change of pore water and cold shock, and cold shock was mainly discussed. The results indicate that the effect of cold shock is still crucial at low water saturation, but it is limited by the degree of temperature drop. In general, freeze-thaw action of liquid nitrogen can cause damage to pore structure, promote the formation of fracture networks, and consequently improve the permeability of coal rock.