Papers by Keyword: Particle

Abstract: The application of a neuron network to a bio/micro-sensor has potential as a drug screening device. In this study, micro-structures of surface-modified particles were applied to a scaffold for selective cell adhesion and growth. Silica particles were covered with a specific protein (fibronectin) or multi-walled carbon nanotubes (CNT) by electrostatic adsorption or transfer printing, respectively. They formed spatial patterns in a line-and-space structure tens of micrometers wide on a glass substrate. This paper investigates the effect of the coated material on the selectivity and adhesiveness of PC12 phenochromocytoma cells. An incubation process causes PC12 cells to autonomously align with selective adhesion on the micro-structures of both particles. The cells are minimally adhered to the glass surface around the particles. The structure of the fibronectin-coated particles enables a straight and uniform alignment of adhered cells, while that of bare silica particles causes randomly distributed cells. It was also found that the structure of CNT-adsorbed particles enhances cell adhesiveness to grow pseudopods of adhered cells.

Abstract: A legume straw-1-butyl-3-methylimidazolium chloride ([C₄mim]Cl)-water solution (dissolved lignocelluloses content: 1.5 wt%) was firstly prepared at 150 °C for 2 h. Lignocellulosic microparticles formation was investigated by adding the reconstitution agent (water, ethanol or acetone) at different reconstitution agent/solution ratio (0.1~0.3 ml/ml). The results indicate that lignocellulosic microparticles (< 17 µm) can be produced in this reconstitution process. The size distribution of obtained microparticles shows normal distribution. The average size of particles increases with an increase of reconstitution agent/solution ratio. The addition of ethanol or acetone promotes the particles aggregation and results in larger particles formation than that of water.

Abstract: Ventilation is important for controlling the airborne transmission of infectious respiratory diseases, particularly in crowed and enclosed spaces, where exist higher risks of cross-infection. This paper studies the spatial concentration distribution and particle tracks of students talking continuously in a classroom with two air distribution methods, including mixing ventilation (MV) and displacement ventilation (DV) using CFD simulations. The classroom is occupied by 10 students with a seating arrangement of 5 rows and 2 columns. The objective of this study is to find out which ventilation mode is more effective in removing respiratory aerosols. The simulation results indicated that the displacement ventilation with the low air supply velocity magnitude and low turbulence could remove the respiratory aerosol droplets and minimize the risk of infectious effectively compared with mixing ventilation.

Abstract: Using a two-dimensional Discrete Element Method (DEM) computer simulation, dense granular flows with the particle size range of 2-3 mm were studied between two vertical waved plates. The hydrodynamic characteristics, such as flow pattern, distribution of stress, velocity and trajectory of particles were analyzed in the process of granular flow. The results were compared to those of the flows between two vertical flat plates. The results indicated that the transient stress between waved plates was heterogeneous; the zigzag-like pressure profiles on the waved pate increased. Conclusions could be drawn that the formation of dense particle clusters disturbed spatial homogeneity and resulted in collisional anisotropy which was propitious to enhance the process of momentum, heat and mass transmission.

Abstract: To prepare ultra-fine particles and offer correlative applications such as the micronization of drugs with rapid expansion of supercritical solution (RESS), the first work in measuring the solubility of risocaine has been carried out at different operation conditions in this paper. The trend of solubility due to changes in specific operational parameters has been examined. The results of pressure (9-30 MPa) and temperature (308-328K) effecting on solubility show that the solubility increases mainly along with the increasing density. With applying different models to correlate the solubility data, we found Chrastil models had better correlation effects than the Peng Robinson EOS model, Mendez-Santiago and Teja equation model, with providing a nearly perfect average absolute relative deviation (AARD) of 0.0596. In the second part of work, RESS was applied to prepare risocaine particles at five different process conditions, including extraction temperature (308-328K), extraction pressure (9-30MPa), nozzle temperature (100-120°C), nozzle diameter (0.1-0.4nm) and spray distance (2-4cm).The size and morphology were determined by scanning electron microscopy (SEM). On the basis of the different experimental operation conditions, granular, filmily and threadlike particles with diameter (1-100nm) were obtained, it was also demonstrated that a successful size reduction of risocaine particles.

Abstract: In this paper, design problems on rotating cone reactor have been studied and dynamics problems have been analyzed in detail, kinematics differential equation of mixture in rotating cone reactor and simulation model has been established. Rotating cone reactor prototype which was established preliminarily has been optimized with simulation software. Dynamics analysis and simulation is of great significance in raising the efficiency of BIO-FUEL-OIL flash pyrolysis rotating cone reactor, control production process reliably, and even optimizing design value and physical dimension which is reasonable in design and reducing the cost of product development process.

Abstract: Self-assembled particles have a wide surface area and thus can improve the sensitivity of biochemical sensors that utilize surface reaction. This paper discusses the self-assembly on a convex lens and condensing characteristic of the fluorescence light emitted from the particles. Silica particles of 1 μm in diameter were assembled on a convex lens and then an immunoassay (antigen-antibody reaction) was carried out on it. It was confirmed that the fluorescence emitted from the particles were condensed at the focal point just the same as in traditional optics. This result can be applied to the improvement of sensitivity and simplification of the system by eliminating fluorescence microscopy.

Abstract: This paper introduces new equipment for injection liquid inspection. The Intelligent Inspection Machine is based on linear CCD. The inspection platform, holding device and rotating and abruptly stopping station of this equipment are introduced, and the operating principle is illustrated. Image preprocessing is demonstrated in details, including filtering, segmentation and the calculated of particles. The experiments demonstrated that the intelligent inspection machine for injection liquid inspection based on linear CCD is feasible.

Abstract: The application of process tomography (PT) technologies, i.e. Electrostatic Tomography (EST) and Electrical Capacitance Tomography (ECT) to investigate complex industrial processes has obtained wide popularity in recent years. This study focuses on the characterization of non-uniformly distributed electrostatic effects across the cross-section of a pneumatic transportpipe. A digital electrometer was used to measure the electrostatics current and an ECT was used to observe the particle distribution in a vertical pipe. Due to non-uniform particle-wall collisions, the electrostatics generated was observed to be non-uniformly distributed across the pipe cross-section, especially at pipe bends and in a vertical pipe. Large electrostatic effects were associated with high particle concentration in the pipe. There was a good correspondence between the electrostatic effects measured and particle concentration distributions obtained using ECT. Based on ECT measurements at the vertical pipe section, it was observed that particles tended to concentrate at sections where generation of electrostatic charges was high. Thus, it is clear that electrostatic effects should be the key factor giving rise to non-uniform particle concentration distribution in pneumatic transport lines.

Abstract: The effect of second-phase particles on the deformation and annealing behaviour of metals is re-assessed in the light of some new techniques. Using an EBSD method which provides much improved angular resolution, the effect of small non-deformable particles on the homogeneity of the deformation microstructure has been quantified. The presence of micron sized second-phase particles alters the deformation microstructure adjacent to particles, and a 3-d investigation of the deformation structures associated with large (>1μm) second-phase particles in cold rolled aluminium alloys has been carried out using 3-d FIB sectioning combined with EBSD, and the microstructures compared with the predictions of 3-d CPFEM modelling. The effects of grain orientation, strain and particle size have been investigated, and the results compared with earlier TEM investigations of such microstructures.