Optical and electronic properties of cobalt-doped zinc oxide films prepared by the sputtering method

In-doped ZnO, Co-doped ZnO and Li-doped NiO are successively deposited on quartz by the sputtering method. A current versus voltage curve of the three-layer device, in which the Indoped ZnO and Li-doped NiO are used as electrodes, reveals that the In-doped ZnO is an ohmic electrode and the Li-doped NiO is a blocking electrode with respect to electron injection. In photocurrent spectra of the three-layer device, there are two distinct peaks around 410 and 640 nm. The former is ascribed to the photoionization caused by the electric-dipole transition from the ground states,⁴A₂(F), to the conduction band, and the latter to the thermal emission from electronic excited states of Co²⁺,⁴T₁(P).     

Segregation in sputtered Co-Cr films

The segregation growth process in sputtered Co-Cr films is investigated by examining the effect of substrate temperature on the segregated microstructure and magnetic properties. In sputtered Co-25at%Cr films, segregation occurs below 560°C, and both the saturation magnetization and the perpendicular anisotropy constant show a maximum around a substrate temperature of 300°C, where a specific microstructure, called a CP (chrysanthemum-like pattern) structure, is observed. The results suggest that the CP structure becomes observable in the highly segregated state and generates high perpendicular anisotropy. A new segregation growth model is derived from the results of the CP structure observations. Using this model, it is possible to explain the continuous transition of the magnetization mode between the continuous and the particulate modes.     

90-nm process-variation adaptive embedded SRAM modules with power-line-floating write technique

The power consumption of a low-power system-on-a-chip (SoC) has a large impact on the battery life of mobile appliances. General SoCs have large on-chip SRAMs, which consume a large proportion of the whole LSI power. To achieve a low-power SoC, we have developed embedded SRAM modules, which use some low-power SRAM techniques. One technique involves expanding the write margin; another is a power-line-floating write technique, which enables low-voltage write operation. The power-line-floating write technique makes it possible to lower the minimum operating supply voltage by 100 mV. The other techniques involve using a process-variation-adaptive write replica circuit and reducing leakage current. These techniques reduce active power during write operations by 18% and reduce active leakage of the word-line driver by 64%. The prototype SRAM modules achieve 0.8-V operation, and a 512-kb SRAM module achieves 48.4-/spl mu/A active leakage and 7.8-/spl mu/A standby leakage with worst-leakage devices.     

Simultaneous measurement of the resistivity and permeability of afilm sample with a double coil

A method is proposed for a simultaneous measurement of the resistivity and permeability of a film inserted between two coils facing each other. Connecting in series, the total impedance of the coils was measured in two ways, i.e., 1) the current passes through the coils in the same direction, and 2) the current passes through each coil in opposite directions to each other. The resistivity and permeability of the film were simultaneously obtained from the difference in the impedance for the two cases. It was theoretically found that the optimum frequency for high accuracy in the measurement was proportional to the resistivity and inversely proportional to a thickness of a sample film. The results of the simultaneous measurements of the resistivity and permeability of nickel films of a thickness ranging from 0.01-0.08 mm at a frequency range of 1-100 kHz are shown in this paper. The measured values of the resistivity and permeability with this method agreed with the values obtained by conventional methods, i.e., the dc four-probe method for the resistivity measurement and the toroidal coil method for the permeability measurement     

Skew simulation of a paper transferred by rubber rollers in printers

A skew of a paper transferred by rubber rollers in printers is simulated by FEM software. Effects of an imbalance of preload, an imbalance distribution of coefficient of friction and a front tension on the paper skew are investigated and how to determine the skew direction are shown. A simulation model is composed of a feed roller, a preload roller and a paper. The feed roller is rotated forcibly by a certain degree at every calculation step and a deformation, displacement and strain of the paper and rollers are calculated. A series of calculation results is shown as a motion simulation. The results show that the paper skews to the smaller preload side, to the smaller coefficient of friction side, or to the opposite side of the front tension. Further, effects of a skew prevention guide plate is simulated.     

A clinical study of respiratory infection isolating non-pathogenic Neisseria by transtracheal aspiration]

Neisseria species other than N. meningitidis and N. gonorrhoeae are generally regarded as commensal bacterial flora of the oropharynx, and little is known regarding cases of these non-pathogenic Neisseria species in the lower respiratory tract. We clinically examined respiratory tract infections from which non-pathogenic Neisseria species were isolated by transtracheal aspiration (TTA). The incidence of non-pathogenic Neisseria isolated was 54 (15.7%) out of 344 episodes of respiratory tract infections with isolated microorganisms from TTA, and was 17.6%, 15.8%, 14.3% for pneumonia, acute bronchitis, and chronic lower respiratory tract infection, respectively. All 54 episodes were isolated with other microorganisms such as alpha-Streptococcus spp. (75.9%), Haemophilus influenzae (25.9%) and anaerobics (22.2%). The isolation ratio according to the age group increased at 45 years of age or more, but did not increase with the advance of age. Predisposing factors were identified such as overt aspiration, iatrogenic procedure and heavy smoking. Cases without overt aspiration that had fevers of 38 degrees C or more or hypoxemia of less than PaO2 70 torr when detecting non-pathogenic Neisseria were observed more frequently in the aged than the non-aged. The findings suggest the detection of non-pathogenic Neisseria by TTA is influenced by the host state that the fall of microorganisms from the upper to lower respiratory tract cannot be defended or excluded by mucociliary transportation disorder due to underlying disease and smoking, or deterioration of physical status other than overt or silent aspiration.     

Measurement of serum p53 protein in patients with small cell lung cancer and results of its clinicopathological evaluation

Serum p53 protein levels were measured in 36 patients with small cell lung cancer (SCLC) and 35 patients with benign lung diseases in order to evaluate the relationship of these levels to clinicopathological features of SCLC. Serum levels of p53 protein were measured by an enzyme-linked immunosorbent assay, p53 protein level was 23.92 +/- 6.78 pg/ml in patients with SCLC, and similar to that (17.47 +/- 2.86 pg/ml) in patients with benign lung diseases. By the clinical stage of SCLC, the mean level of p53 protein was 16.68 +/- 4.62 pg/ml in 21 patients with limited disease, and lower than that in 15 patients with extensive disease (34.05 +/- 14.84 pg/ml) (P = 0.23). The levels of p53 protein were not correlated with age, smoking index, or presence of cancer history for patients with SCLC. However, immunohistochemical examination disclosed a mild correlation between the expression of p53 protein by SCLC tumor and p53 protein serum level (r = 0.45, P = 0.02). Two patients with SCLC had an elevated serum level of p53 protein (> 2 S.D. above the mean for benign lung diseases). However, measurement of p53 protein serum level was not found to be clinically useful for detection of SCLC.