Lithium Ion Secondary Cell Prepared by a Printing Procedure,and Its Application to All-Solid-State Inorganic Lithium Ion Cells

We have developed a straightforward printing method for preparation of a lithium secondary cell. LiCo_1/3Ni_1/3Mn_1/3O₂ and Li₄Ti₅O₁₂ viscous printable pastes were used for the cathode and anode, respectively. Electrochemical measurement was used to characterize the capacitance of each cell, and field-emission scanning electron microscopy and particle size measurements were used to characterize particle size and morphology. These film electrodes functioned stably both in a standard liquid electrolyte and in an Li₂SiO₃ solid electrolyte, although the capacitance of the all-solid-state cell was significantly lower than that of the cell containing liquid electrolyte. When liquid electrolyte was used, the capacity decreased by 36% after 50 cycles. However, the capacity of 0.2 mA h/g remained almost the same even after 50 charge–discharge cycles, demonstrating the stability and strength of the all-solid-state lithium ion cell. It was also found that the cell resistance mostly arose from the electrode/electrolyte interface and not from the bulk electrolyte. Addition of a sol–gel to the solid electrolyte printable paste improved cell performance.     

MR imaging of the central nervous system in divers

BACKGROUND: Magnetic resonanse imaging (MRI) frequently reveals asymptomatic cerebral infarctions in the general population. HYPOTHESIS: The central nervous system (CNS) of divers is affected by a hyperbaric environment even if they are asymptomatic. METHODS: We examined 25 uniformed service divers by MRI and compared them with normal controls. RESULTS: Of 25 divers, 9 had CNS lesions vs. 2 of 25 controls (p = 0.02). There was a significant relationship between the CNS lesions, age, and smoking. CONCLUSION: The divers had a risk of accumulating CNS lesions. These results suggested that divers should undergo periodic medical evaluations and MRI brain scanning.     

Endoscopic stone disintegration using the Lithoclast

We present our experience with a new and unique device for performing intracorporeal lithotripsy known as the Swiss Lithoclast. This simple device uses compressed air to activate a solid probe in a manner of a jackhammer. This device was used to treat 20 patients with stones in the ureter (11), bladder (5) or a Kock pouch (4). The Lithoclast successfully fragmented 90% of the calculi independent of the composition and salvaged 2 failed ESWL treatments. At one month after the procedure, either alone or in combination of with ESWL, 17 of 20 patients became free of stones. There were no complications related to use of the device. We have found the Swiss Lithoclast to be a safe and effective means of performing intracorporeal lithotripsy for urinary calculi.     

Microstructure of carbonaceous mesophase spherule

Carbonaceous spherules of mesophase were examined by transmission electron microscopy (TEM) and X-ray diffraction to precisely clarify its structure. A series of thin sections were cut from a single spherule with a microtome, and the three-dimensional lamellar structure of the spherule investigated. From 002 dark-field images and selected area electron diffractions (SAD), it was observed that the spherule was of the Brooks-Taylor type, with the lamellae being parallel even at the poles of the spherule. Structural changes within the spherule was studied following carbonization and graphitization. The structure of the resultant coke was essentially that of spherule of mesophase. Size of the lamellae increased as well as. The number of stacking lamellae also increased, but a rapid increase was not seen. The spherules of mesophase show a high degree of homogeneity and an excellent degree of graphitization.     

High-temperature deformation and fracture behaviour of Cu-SiO2 bicrystals

Bicrystals of CU-SiO₂ dispersion-hardened alloys and of pure copper were tensile tested at various temperatures between 450 and 1050 K at a strain rate of 1.5 x 10^–4 sec^–1. In the case of pure copper bicrystals, elongation to fracture did not depend significantly on temperature and the fracture mode was invariably transgranular up to 850 K. On the other hand, the ductility of CU-SiO₂ bicrystals decreased with increase in temperature and the transition in the fracture mode from transgranular to intergranular occurred at around 450 K. SiO₂ particles on grain boundaries play an important role on intergranular fracture by suppressing grain-boundary sliding and also on the retardation of recrystallization during deformation. Two types of Cu-SiO₂ bicrystals having different crystal orientation relationships show quite different deformation and fracture behaviour. This can be explained in terms of the contribution of lattice dislocations to the grain-boundary sliding.