BER Performance of Frequency Domain Differential Demodulation OFDM in Flat Fading Channel

A closed form expression for the bit error rate (BER) performance of frequency domaindifferential demodulation(FDDD) for orthogonal frequency division multiplexing system in flat fadingchannel is derived.The performance is evaluated by computer simulation and compared with the timedomain differential demodulation(TDDD).The results indicate that the performance of FDDD is betterthan that of TDDD,and the lower band of BER in the former is lower than that of the latter.     

Processing of nanolitre liquid plugs for microfluidic cell-based assays

Plugs, i.e. droplets formed in a microchannel, may revolutionize microfluidic cell-based assays. This study describes a microdevice that handles nanolitre-scale liquid plugs for the preparation of various culture setups and subsequent cellular assays. An important feature of this mode of liquid operation is that the recirculation flow generated inside the plug promotes the rapid mixing of different solutions after plugs are merged, and it keeps cell suspensions homogeneous. Thus, serial dilutions of reagents and cell suspensions with different cell densities and cell types were rapidly performed using nanolitres of solution. Cells seeded through the plug processing grew well in the microdevice, and subsequent plug processing was used to detect the glucose consumption of cells and cellular responses to anticancer agents. The plug-based microdevice may provide a useful platform for cell-based assay systems in various fields, including fundamental cell biology and drug screening applications.     

Effect of Water on Extractive Desulfurization of Simulated FCC Gasoline Using Ionic Liquid NMP-FeCl_3-H_2O

A series of novel aqueous ionic liquids(NMP-FeCl_3-nH_2O) were prepared and the effects of water in the aqueous ionic liquids on desulfurization rate and selectivity of simulated FCC gasoline were investigated. The results showed that adding a small amount of water into the ionic liquid NMP-FeCl3 could effectively improve the desulfurization rate and selectivity, and the optimal amount of water was equal to 5%―10% of NMP. Finally, the possible desulfurization mechanism activated by a small amount of water was proposed.     

Secure optical data storage with random phase key codes by use of a configuration of a joint transform correlator

A secure optical storage based on a configuration of a joint transform correlator by use of a photorefractive material is presented. A key code designed through the use of an optimized algorithm so that its Fourier transform has a uniform amplitude distribution and a uniformly random phase distribution is introduced. Original two-dimensional data and the key code are placed side-by-side at the input plane. Both of them are stored in a photorefractive material as a joint power spectrum. The retrieval of the original data can be achieved with the same key code. We can record multiple two-dimensional data in the same crystal by angular multiplexing and/or key code multiplexing.     

Formation and emission of volatile polonium compound by microbial activity and polonium methylation with methylcobalamin

We observed biologically mediated emission of Po from culture solution inoculated sea sediment extract and incubated under natural light/dark cycle condition or dark condition the emitted Po compound would be lipophilic because of effective collection in organic solvent. Sterilization of the culture medium with antibiotics or CuSO4 completely suppressed growth of microorganisms and resulted in no emission of Po, indicating biological activity of microorganisms is responsible for formation and emission of volatile Po compound. Po emission also occurred when seawater was used as a culture medium. Our finding indicates a possibility of biotic source for atmospheric Po in the environment, which has been believed to be originated from abiotic sources. We compared emission behavior of Po and S in the culture experiments, the elements belong to XVI group in the Periodical Table, and consider that their emission mechanisms involved would be different though the emission of both elements is supported by biological activity of microorganisms. One of the chemical forms of S emitted was confirmed to be dimethyl sulfide (DMS) but that of Po is not known. Methylation experiments of Po with methylcobalamin demonstrated a formation and emission of volatile Po compound. The methylation of Po with methylcobalamin might be related to the observed Po emission in the culture experiments.     

Fabrication of Nanocomposite Ceramics by Crystallization of Rapidly Solidified Eutectic Melts

Eutectic melt solidification is shown to avoid cracking during solidification by quenching an amorphous phase. Subsequent annealing results in micro/nanostructure ceramics. This strategy has been applied to HfO₂–Al₂O₃–GdAlO₃ and Y₂O₃–CaO–Al₂O₃ ternary systems that have deep eutectics. In most cases, ceramic materials cracks when they are solidified from melt due to the thermal stress accumulated on the grain boundaries, the large specific volume difference between the melt and the crystalline solid, etc. The main reason why this strategy works is that a eutectic composition yields an amorphous phase from the melts by rapid cooling and the amorphous phase enables to design crystallization without cracking by postannealing. Appropriate postannealing for the quenched amorphous enables to control the crystallization behavior from the amorphous phase, which yields nanostructured composites without cracking. For the HfO₂–Al₂O₃–GdAlO₃ case, the melt solidification and postannealing yields a nanocomposite with high transparency due to reduced scattering of 5–10 nm crystallites. For the Y₂O₃–CaO–Al₂O₃ case, a plate-shaped bulk composite is obtained without cracking by molding the melt and postannealing.     

Smoking prevalence of female nurses in the national hospitals of Japan

OBJECTIVE: To estimate the prevalence of smoking and the attitudes towards the restriction of smoking at work among female nurses in the national hospitals in Japan. DESIGN: Questionnaires mailed to 14 randomly selected national hospitals and sanitariums in Japan in 1993. SUBJECTS: 2207 female nurses. MAIN OUTCOME MEASURES: Smoking status and history, and attitudes towards the restriction of smoking at work. RESULTS: The prevalence of smoking among female nurses was 18.6%, which was higher than the age-adjusted prevalence of the general female population using this study's subjects as a standardised population. Banning smoking in the hospital in which they worked was supported by 15.0%, whereas 81.6% supported the restriction of smoking. CONCLUSIONS: The results showed that smoking is more common among female nurses than among the general female adult population. The survey suggested that nurses favour restriction, but not banning, of smoking.