A Raman spectroscopic method to find binder distribution in electrodes during drying

Lithium ion batteries are used extensively in electronic devices as well as hybrid and electric vehicles. The anode electrode layer in the battery can be fabricated by coating an aqueous dispersion of carbon, binder, and additives, and then drying. During manufacturing, the distribution of the binder through the coating thickness can become nonuniform, which compromises the properties and performance of the battery. In this study, a quantitative method to analyze the binder distribution in the electrode during drying was established. A drying apparatus with an integrated analytic balance and surface-temperature measurement was used to prepare specimens. At specific time points during drying, specimens were removed from the apparatus, quickly frozen, and then freeze-dried. Raman spectroscopy was then used to measure the binder concentration at different points through the cross section of the freeze-dried electrode coating. Scanning electron microscopy was also used to explore the changing microstructure qualitatively. Using a model electrode formulation, the method demonstrated different binder distributions for electrodes dried at 150°C under airflow and room temperature, 20°C, with no airflow. The results also showed continued changes in distribution in the interior of the coating as drying continued.     

Interface Stress Response of Laminated Plates Subjected to Static and Impact Loads

This paper deals with the stress analysis of laminated sandwich beams subjected to static loads and impact loads. When the laminated sandwich beams are subjected to static loads, stress distribution at the interfaces is analyzed, by using two-dimensional theory of elasticity, as a contact problem. When the laminated sandwich beams are subjected to impact loads, the interface stress response is analyzed using FEM (DYNA3D). Experiments were conducted. A fairly good agreement is seen between the analytical and the experimental results. The effects of the ratios of Young's moduli for each beam on the interface stress response are clarified.     

Mechanical properties of poly(ε-caprolactone) composites with electrospun cellulose nanofibers surface modified by 3-aminopropyltriethoxysilane

To enhance the reinforcement effects of regenerated cellulose nanofibers (RC-NF) in poly(ε-caprolactone) (PCL), we synthesized RC-NF-3-aminopropyltriethoxysilane (APS), the surface-modified RC-NF by APS. The RC-NF were fabricated by the saponification of electrospun cellulose–acetate nanofibers. The surface modification by APS was confirmed by the X-ray photoelectron spectroscopy (XPS). To enhance the mechanical property of PCL, the RC-NF and the RC-NF-APS were separately compounded into PCL by compression molding. It was found that, when the fiber concentration of RC-NF-APS was 17 wt %, the Young's modulus at room temperature increased from 698.0 to 744.7 MPa, whereas the storage modulus at 55 °C almost increased from 180 to 220 MPa. The micrographs of the fracture surface of the composites revealed that the surface modification prevented the pull-out of RC-NF from PCL. It was concluded that the mechanical properties of the composites were enhanced due to the improvement of the compatibility between RC-NF and PCL by the surface modification with APS. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48599.     

Transgenic expression of VpreB-3 under the control of the immunoglobulin heavy chain enhancer and SV40 promoter

Recently we isolated a novel gene, VpreB-3 gene from the cDNA library of a pre-B cell clone. This gene is selectively expressed in pre-B and bone marrow-derived B cell lines. Its products are associated with the immunoglobulin heavy (IgH) chain in pre-B cell line. In the present study, to address the role of VpreB-3 on B cell development, transgenic mice carrying the VpreB-3 gene under the control of the IgH enhancer and SV40 promoter were produced. The transgenic mice expressed the VpreB-3 gene in bone marrow and spleen at a high level compared with control mice. In the thymus, the expression of the transgene was also detected, although its level was low. Flow cytometry analysis revealed that the frequency of CD45R+ and mu+ B cells were reduced in the bone marrow of 2 of the 11 transgenic mice and also reduced in the spleen of 1 of the transgenic mice. Furthermore, the results of a stromal cell-dependent B cell culture assay suggested that early B cell development, the differentiation from CD45R- B progenitor cells to CD45R+ pro-B cells, was delayed in the bone marrow cultures of 3 of the 5 transgenic mice compared with the control mice. These results suggested that VpreB-3 products may play some role in early B cell development at the stage of CD45R- B progenitor cells before the expression of surface mu chains.     

Inhibitory effects of phenolic compounds on development of naturally occurring preneoplastic hepatocytic foci in long-term feeding studies using male F344 rats

Five phenolic compounds, namely caffeic acid, sesamol, hydroquinone, catechol, and 4-methoxyphenol, were fed to groups of 30 male F344 rats at dietary levels of 2, 2, 0.3, 0.8, and 2%, respectively, for 2 years. Retardation of body weight and elevated relative liver weights were noted for all groups. Formalin-fixed and paraffin-embedded liver tissues from rats killed terminally were cut and stained for glutathione S-transferase placental form (GST-P) and tumor growth factor alpha (TGF alpha) immunohistochemically. Numbers and areas of GST-P-positive (GST-P+) foci per unit area of liver section were measured, and the respective treated/control proportional values were calculated to be 58 and 57% for caffeic acid. 58 and 54% for sesamol, 71 and 71% for hydroquinone. 58 and 133% for catechol, and 49 and 39% for 4-methoxyphenol. These data were comparable with results obtained with medium-term liver bioassays (Ito test). However, no intergroup differences were detected with regard to quantitative findings for TGF alpha foci, which were relatively rare. Long-term inhibitory effects of phenolic compounds on liver carcinogenesis, predicted from the Ito test, were thus confirmed in the present feeding studies using quantitative analysis of immunohistochemically demonstrable GST-P+ foci as end point marker lesions.     

Position and Rotation Estimation for Mobile Robots in Outside of Recording Path Using Ego‐Motion

In this research, estimating the position and rotation of a mobile robot outside of a recording path is realized by applying ego‐motion to view‐based navigation. The ego‐motion is calculated based on the differences in 3D positions of SURF feature points between recording and current images obtained by a Kinect sensor. In conventional view‐based navigation, it is difficult to plan another path when people and objects are found in the recording path. By using the authors’ proposed estimation method, it is possible to realize flexible path planning in actual environments that include people and objects. Based on the results of experiments performed in actual indoor environments, the authors evaluated measurement accuracy for the robot's position and rotation estimated under their method, and confirmed the viability of their method for actual environments including people and objects.     

Effects of grain refinement on surface enhancement of thin-film chlorine-doped crystalline selenium

In this study, the surface enhancement of thin-film crystalline selenium (c-Se) is successfully demonstrated through grain refinement using chlorine (Cl) doping. We fabricated c-Se films via doping with various halogens, such as Cl, bromine (Br), and iodine (I). In particular, for Cl, we prepared c-Se films with different doping concentrations of 0, 50, and 500 ppm on glass substrates to investigate the details of concentration effects on surface enhancement. The long helical chains of Se atoms that comprise a large molecule in hexagonal Se, which is the most stable form of Se, are terminated via halogen doping into Se, leading to a marked reduction in the size of polycrystalline grains. In addition, the grain size of c-Se sharply decreases as the Cl doping concentration is increased. The mean surface roughness of a 500-ppm-Cl-doped c-Se film measured via atomic force microscopy decreased to approximately one-fourth that of the equivalent undoped c-Se film. This is a promising technology that could bring great benefits to c-Se-based imaging devices.     

On H/sub /spl infin// model reduction using LMIs

In this note, we deal with the problem of approximating a given nth-order linear time-invariant system G by an rth-order system G/sub r/ where r相似文献   

Simultaneous pole assignment by multi-structured multirate sampled-data controllers—orthogonality consideration

A new method of simultaneous pole assignment and simultaneous stabilization of h plant models P_j (j = 1, …, h) by multirate sampled-data controllers is presented. The method is based upon two key ideas. The first is the introduction of the ‘perturbation structure’ assumption on the plant models; i.e., it is assumed that a part of P_j is fixed for all j and the rest is changed completely. This assumption seems fairly feasible if P_js are the models of a single object under different conditions or the models of many objects which perform the same function. The second key idea is the use of multi-structured multirate sampled-data controllers, which might offer a new horizon for a wide class of control problems other than simultaneous stabilization. The significance and feature of the proposed method in contrast with a previous method are clarified from the viewpoint of ‘controller-plant orthogonality’. Namely, we show that the resulting controller can be regarded as consisting of h subcontrollers each of which controls its target plant model but causes no feedback effect at sampling instants on other h—1 plant models.