Considered as a less hazardous piezoelectric material, potassium sodium niobate (KNN) has been in the fore of the search for replacement of lead (Pb) zirconate titanate for piezoelectrics applications. Here, we challenge the environmental credentials of KNN due to the presence of ~60 wt% Nb2O5, a substance much less toxic to humans than Pb oxide, but whose mining and extraction cause significant environmental damage.

A total of 245 patients with confirmed 2009 H1N1 influenza were admitted to the intensive-care units of 28 hospitals (South Korea). Their mean age was 55·3 years with 68·6% aged >50 years, and 54·7% male. Nine were obese and three were pregnant. One or more comorbidities were present in 83·7%, and nosocomial acquisition occurred in 14·3%. In total, 107 (43·7%) patients received corticosteroids and 66·1% required mechanical ventilation. Eighty (32·7%) patients died within 30 days after onset of symptoms and 99 (40·4%) within 90 days. Multivariate logistic regression analysis showed that the clinician's decision to prescribe corticosteroids, older age, Sequential Organ Failure Assessment score and nosocomial bacterial pneumonia were independent risk factors for 90-day mortality. In contrast with Western countries, critical illness in Korea in relation to 2009 H1N1 was most common in older patients with chronic comorbidities; nosocomial acquisition occurred occasionally but disease in obese or pregnant patients was uncommon.

We investigated the effects of V/III flux ratios on the Curie temperature, T C , in Ga1−x Mnx As layers with various Mn mole fractions of x = 0.03 and 0.05. A 75 nm thick GaMnAs layer was grown at the temperature of 250 °C with various V/III flux ratios of 25∼34. The low temperature molecular beam epitaxy (LT-MBE) method for growth of GaMnAs layer caused the defects related by excess As and Mn interstitial, and these leaded the formation of deep level. We investigated that formation of deep level was established with various Mn mole fraction for V/III flux ratio 34. The changes of T C are observed by varying V/III flux ratio with a fixed Mn mole fraction. The T C in the sample grown with a lower V/III flux ratio of 25 is found to be higher comparing to that with higher V/III flux ratio of 34 at a fixed high Mn concentration (x = 0.05). Although the Mn concentration increases, the T C is not much changed when the V/III flux ratio is high of 34. The changes of T C with various V/III flux ratios are explained by the existence of low temperature grown defects, which are clarified by the deep level transient spectroscopy measurement. The prime species of defects are found to be AsGa and MnI etc.

With respect to the operation of a Phase-change Random Access Memory (PRAM or PcRAM), we studied the effect of the contact between the electrode metal and the chalcogenide glass, N2 doped Ge2Sb2Te5 in this report. We investigated a change of the resistance-programming current pulse (R-I) curve varying the contact size and the electrode material. Also we tested the surface oxidation of the electrode. We found that the programming current, the resistance of the programmed state (“RESET”) and the erased state (“SET”) were highly dependent on the above parameters. These results are presented and a more effective way to the high density PRAM will be proposed.

Real time spectroscopic ellipsometry (RTSE) has been applied to identify optimal conditions for the nucleation and growth of 120 Å microcrystalline silicon (μc-Si:H) p-layers by rf plasma-enhanced chemical vapor deposition (PECVD) at 200°C on amorphous silicon (a-Si:H) i-layers in the n-i-p solar cell configuration. Analysis of the RTSE data provide the bulk p-layer dielectric function (2.5-4.3 eV), whose amplitude and shape yield insights into the structural quality and crystallinity of the p-layer. Among the deposition parameters varied include the underlying i-layer surface treatment, the p-layer plasma power flux, and the p-layer dopant source gas and flow ratio. Here we focus on the differences between p-layer deposition using trimethyl boron, B(CH3)3, and boron trifluoride, BF3, source gases. We find significant differences attributed to the differing effects of F and CH3radicals in the plasma on silicon crystallite growth.

X-ray pulsars are the only accreting magnetic stars where rotation torques induced by accretion are large enough to be measured on short timescales ~ days. They are thus unique laboratories for studying the interaction between an accretion disk and a stellar magnetosphere. We describe 5 years of continuous pulsar timing observations by the BATSE instrument on GRO which paint a strikingly different picture of pulsar spin behavior than understood from the previous 20 years of sparse observations. In particular, we find that more than half of the persistent pulsars we observe undergo dramatic torque reversals, switching suddenly between extended periods of steady spin-up and steady spin-down. Moreover, variations in pulsed flux are anticorrelated with torque in at least one system undergoing secular spin-down, GX1+4. This behavior contradicts standard accretion torque theory (Ghosh and Lamb 1979). A simple – albeit unconventional – hypothesis which naturally explains these observations is that the disks in these systems somehow alternate between epochs of prograde and retrograde rotation.

Ar ions with 1 keV energy was irradiated on aluminum nitride in an O2 environment to increase the bonding strength with Cu and also on alumina in an N2 environment to increase the bending strength. Cu(1000 Å) films were deposited by ion-beam sputter on Ar+ irradiated/unirradiated A1N surfaces and the change of the bond strength was investigated by a scratch test. For the study of chemical structural change on the Ar+ irradiated A1N surface, Cu(50Å) were deposited on an A1N substrate and XPS depth profile analysis was performed. Cu films deposited on Ar+ irradiated A1N under an O2 environment showed the bond strength of 30 Newton by a scratch test. On the basis of Cu3p, A12p near core levels and OI s, N1 s core level spectra, it was found that the improvement of bond strength of Cu films on the AlN surface resulted from the formation of intermediate layers such as copper oxide and aluminum oxynitride. The bending strength of polycrystalline alumina irradiated by Ar ions in an N2 environment was also increased.