Evaporation-induced pattern formation in polymer films via secondary phase separation

The ordered necklace-like or cellular pattern formation has been investigated for ternary polymer solutions in which primary and secondary phase separations were induced by the solvent evaporation. The patterns consisted of regular droplet arrays of various diameters, which arose in the pre-existing polymer phases via the secondary phase separation. The pattern formation was enhanced with increasing air velocity and ambient humidity, while it was suppressed with decreasing initial film thickness. The regular pattern was independent of surface wettability of the solid substrate. We ascribe the morphology change to the evaporation-induced surface tension driven convection, which re-arranged the droplet distributions from disordered to flow-induced ordered patterns.     

A Scheduling Protocol for Continuous Media Data Broadcasting With Large-Scale Data Segmentation

Due to the recent popularization of mobile multimedia broadcasting, broadcasting continuous media data such as audio and video has attracted great deal of attention. In general continuous media data broadcasting, since clients have to wait to receive data before playing it, various schemes to reduce waiting time have been studied. Some reduce the waiting time by dividing the data into several segments and broadcasting preceding segments frequently with a single channel. However, by dividing the data into numerous segments and producing an effective broadcast schedule, the waiting time can be further reduced. In this paper, we propose a scheduling protocol to reduce waiting time with large-scale data segmentation.     

Effect of vacuum annealing on field emission from heavily phosphorus doped homoepitaxial (111) diamond

Vacuum anneal treatments effects on field emission properties of phosphorus doped diamond are discussed. The C1s core level of diamond is characterized by X-ray photoelectron spectroscopy (XPS). With increasing annealing temperature, firstly oxygen desorption takes place from surface, which induce surface reconstruction followed by graphitization of surface. Field emission properties, therefore, strongly depend on vacuum anneal temperature. The threshold voltage of diamond annealed at 900 °C is the lowest. Fowler–Nordheim plots indicate that diamond annealed at 900 °C has the lowest barrier height, which is in good agreement with electron affinities as measured on carbon reconstructed surface. Further increased annealing temperature induces surface graphitization, which causes a threshold voltage increase of field emission.     

A resilient mutual exclusion algorithm for computer networks

The authors present an extension to the work of I. Suzuki and T. Kasami (see Proc. 3rd Int. Conf. Distributed Compact Syst., p.365-70 (1982)), where a mutual exclusion algorithm uses a message called a token to transfer the privilege of entering a critical region among the participating sites. The proposed algorithm checks whether the token is lost during network failure, and regenerates it if necessary. The mutual exclusion requirement is satisfied by guaranteeing regeneration of only one token in the network. Failures in a computer network are classified into three types: processor failure, communication controller failure, and communication link failure. To detect failures, a time-out mechanism based on message delay is used. The execution of the algorithm is described for each type of failure; each site follows a rather simple execution procedure. Each site is not required to observe the failure of other sites or communication links     

Parameter estimation for packed cooling tower operation using a heat input-response technique

A method is proposed for predicting the variations of air and water temperatures and of air humidity in a packed bed counterflow type of cooling tower subjected to a thermal disturbance. Heat input-response measurements are carried out by imposing thermal disturbances on inlet water and inlet air. The air-film and water-film heat transfer coefficients are estimated by fitting in the time domain the measured output temperature/humidity variations to those predicted.     

Family M42 aminopeptidase from the syntrophic bacterium Symbiobacterium thermophilum: characterization using recombinant protein

The chromosomal DNA of the syntrophic thermophile Symbiobacterium thermophilum contains open reading frames of the genes encoding family M42 aminopeptidases, Pep1079, Pep1080, and Pep1081. To characterize these peptidases, the genes were cloned into Escherichia coli and overexpressed. Our experiments using the recombinant proteins confirmed that Pep1079, Pep1080, and Pep1081 are components of arginyl or lysinyl aminopeptidases that require Co2+ for enzymatic activity. Coexistence of Pep1079 and Pep1080 is necessary for expressing high peptidase activity. Pep1081 enhances the activity of Pep1079 and Pep1080.     

Compensation algorithm for the phase-shift error of polarization-based parallel two-step phase-shifting digital holography

We propose an algorithm for compensating the phase-shift error of polarization-based parallel two-step phase-shifting digital holography, which is a technique for recording a spatial two-step phase-shifted hologram. Although a polarization-based system of the technique has been experimentally demonstrated, there had been the problem that the phase difference of two phase-shifted holograms had been changed by the extinction ratio of the micropolarizer array attached to the image sensor used in the system. To improve the performance of the system, we established and formulated an algorithm for compensating the phase-shift error. Accurate spatial phase-shifting interferometry in the system can be conducted by the algorithm regardless of phase-shift error due to the extinction ratio. By the numerical simulation, the proposed algorithm was capable of reducing the root mean square errors of the reconstructed image by 1/4 and 1/5 in amplitude and phase, respectively. Also, the algorithm was experimentally demonstrated, and the experimental results showed that the system employing the proposed algorithm suppressed the conjugate image, which slightly appeared in the image reconstructed by the system not employing the algorithm, even when the extinction ratio was 10:1. Thus, the effectiveness of the proposed algorithm was numerically and experimentally verified.     

Fabrication of dense β-calcium orthophosphate with submicrometer-sized grains and its high-temperature superplastic deformation

High-density β-calcium orthophosphate (β-Ca₃(PO₄)₂, also called β-tricalcium phosphate: β-TCP) ceramics with submicrometer-sized grains were fabricated using a pulse-current pressure firing route. The maximum relative density of the β-TCP compacts was 98.7% at 1050 °C and this was accompanied by a translucent appearance. The mean grain size of the β-TCP compacts increased slightly with temperature to reach 0.78 μm at 1000 °C. However, upon further increasing the firing temperature to 1050 °C the mean grain size increased significantly to 1.6 μm. The extent of plastic deformation during tensile testing was examined at temperatures between 900 and 1100 °C using a strain rate in the range 9.26 × 10⁻⁵ to 4.44 × 10⁻⁴ s⁻¹. The maximum tensile strain achieved was 145% for a test temperature of 1000 °C and strain rate of 1.48 × 10⁻⁴ s⁻¹ and this was attributed to the relatively high density and small grain size.     

Effect of gas flow rate on surface morphology and crystal quality of ZnTe epilayers grown on GaAs substrates

The effect of gas flow rate on surface morphology and crystal quality of ZnTe layers grown on the (1 0 0) GaAs substrates by atmospheric pressure metalorganic vapor phase epitaxy with dimethylzinc and diethyltelluride as the source materials was investigated. The surface morphology of the ZnTe epilayers is significantly improved with increasing the total gas flow rate. X-ray rocking curve and photoluminescence measurements indicate that the total gas flow rate plays a vital role in the growth characteristics of the ZnTe epilayers, and the ZnTe epilayer with best crystal quality is obtained at the total gas flow rate around 300 standard cubic centimeters per minute (sccm) in this work.     

Denopamine, a beta1-adrenergic agonist, prolongs survival in a murine model of congestive heart failure induced by viral myocarditis: suppression of tumor necrosis factor-alpha production in the heart

OBJECTIVES: This study was designed to examine the effects of denopamine, a selective beta1-adrenergic agonist, in a murine model of congestive heart failure (CHF) due to viral myocarditis. BACKGROUND: Positive inotropic agents are used to treat severe heart failure due to myocarditis. However, sympathomimetic agents have not been found beneficial in animal models of myocarditis. METHODS: In vitro: The effects of denopamine on lipopolysaccharide-induced tumor necrosis factor-alpha (TNF-alpha) production was studied in murine spleen cells. In vivo: Four-week-old DBA/2 mice were inoculated with the encephalomyocarditis virus (day 0). Denopamine (14 micromol/kg), denopamine (14 micromol/kg) with a selective beta1-blocker metoprolol (42 micromol/kg), or denopamine (14 micromol/kg) with metoprolol (84 micromol/kg) was given daily, and control mice received the vehicle only. Survival and myocardial histology on day 14 and TNF-alpha levels in the heart on day 6 were examined. RESULTS: In the in vitro study, TNF-alpha levels in treated cells were significantly lower than in controls (p < 0.05). In the in vivo study treatment with denopamine significantly improved the survival of the animals (14 of 25 (56%) treated, vs 5 of 25 (20%) control mice), attenuated myocardial lesions, and suppressed TNF-alpha production (66.5+/-7.5 pg/mg of heart in treated mice vs 113.5+/-15.1 pg/mg of heart in control mice, mean+/-SE). There was a strong linear relationship between mortality and TNF-alpha levels (r=0.98, n=4, p < 0.05). These in vitro and in vivo effects of denopamine were significantly inhibited by metoprolol. CONCLUSIONS: These results suggest that denopamine may exert its beneficial effects, in part, by suppressing the production of TNF-alpha via beta1-adrenoceptors.