Performance improvements in temperature reconstructions of 2-D tunable diode laser absorption spectroscopy (TDLAS)

Performance improvement was attained in data reconstructions of 2-dimensional tunable diode laser absorption spectroscopy(TDLAS). Multiplicative Algebraic Reconstruction Technique(MART) algorithm was adopted for data reconstruction. The data obtained in an experiment for the measurement of temperature and concentration fields of gas flows were used. The measurement theory is based upon the Beer-Lambert law, and the measurement system consists of a tunable laser, collimators, detectors, and an analyzer. Methane was used as a fuel for combustion with air in the Bunsen-type burner. The data used for the reconstruction are from the optical signals of 8-laser beams passed on a cross-section of the methane flame. The performances of MART algorithm in data reconstruction were validated and compared with those obtained by Algebraic Reconstruction Technique(ART) algorithm.     

Postural variation of hand precision grips by object size

Our two-fold purpose was (i) to quantitatively identify characteristic vectors, i.e., specific combinations of joint angles of fingers, that dominate the posture variation of precision grips in the configuration space (the space with joint variables of the fingers in the hand), and (ii) to investigate linear correlations between the postural variation and the object size using the parameters of the characteristic vectors. Experiments involving 14 participants measured the grip postures of the participants who were asked to grasp eight cylindrical objects of different diameters using six designated precision grips (spherical, tripod, pinch, quad-pinch, tri-pinch, and mini-pinch). Regression analysis showed that within each precision grip, the postures changed gradually in a unique linear direction in the configuration space with an increasing object size relative to the hand size. Quantitative models of the precision grips were established that could be used to reproduce the precision grip postures for grasping various object sizes by adults of various hand sizes.     

A Specific Groove Pattern Can Effectively Induce Osteoblast Differentiation

Little is known about the principles of surface structure design for orthopedic and dental implants. To find topographical groove patterns that could enhance osteoblast differentiation according to cell type, groove patterns are fabricated with ridges (0.35?7 µm) and grooves (0.65?6 µm) of various widths and explored their mechanisms in improving osteoblast differentiation. This study finds that a groove pattern enhancing osteoblast differentiation is associated with the ability of the cell to extend its length and that it is able to overcome the inhibition of osteoblast differentiation that takes place under inflammatory conditions. The groove pattern suppresses the generation of reactive oxygen species, a reaction that is increased in inflammatory conditions. It also modulates the expression of osteogenic factors according to differentiation time. Importantly, specific groove patterns AZ‐2 and AZ‐4, with ridge width of 2 µm and groove width of 2 or 4 µm, respectively, effectively promote bone regeneration in critical‐sized calvarial defects without additional factors. This knowledge of groove patterns can be applied to the development of orthopedic and dental devices.     

Effect of ash fraction and particle size on ash deposition during pulverized coal combustion

Coal is an important energy source to increase consumption continuously. However, the ash residues from coal combustion have produced ash deposition that causes slagging and fouling in boilers. The goal of this study is to examine the characteristics of ash deposits (i.e., the effects of the ash fraction and particle size) in pulverized coal combustion. For this study, five coals (Suek, Macqurie, Berau, Lanna and Vitol) are used, which have similar chemical components in the ash but differences in the ash fraction. A Thermomechanical analysis technique (TMA) and Drop tube furnace (DTF) are used to analyze the tendencies in the ash fusibility and deposition with temperature, respectively. Moreover, the size and morphology of the fly ash are analyzed for physical changes by using a particle-sizedistribution analyzer and Scanning electron microscopy (SEM), respectively. In the TMA results, all coal types have a similar fusibility because of the similar chemical components in the ash. The order of the deposited mass is Suek, Macqurie, Berau, Vitol and Lanna in accordance with the ash fraction in the DTF. The ash fraction in coal is a major factor in the ash deposit according to these results. The size of the fly ash changed compared to that of the raw coal according to the results of a particle-size analysis and SEM owing to physical processes such as fragmentation, shedding and coalescence during coal burning. On this basis, a deposition model is developed with the ash fraction and particle size. The model results are in good agreement with the measurements. The results demonstrate that the particle size and ash fraction influence the deposit.

     

Generation of Monodisperse,Shape‐Controlled Single and Hybrid Core–Shell Nanoparticles via a Simple One‐Step Process

In nano‐biotechnology, optoelectronics, and energy research areas, various fabrication methods have been developed for hybrid nanoparticles. A method is developed here for fabricating highly monodisperse three‐dimensional hybrid nanoparticles using a unique top‐down method based on secondary sputtering lithography. Nanostructures that have been formed on a PEDOT sacrificial layer are transferred from the substrate to an aqueous solution in a process that could be used to successfully disperse a variety of nanoparticle shapes and hybrid nanoparticles. By this method, a fluorescent dye could be encapsulated within the fabricated hybrid nanoparticles for use in bio‐sensing and drug‐delivery applications