Thermal conductivity and phonon scattering mechanisms in La#x2212;x#x2212;x#x2212;xMxCuO4

The thermal conductivity of high density La_2–xM_xCuO₄ (M=Ba, Sr) sintered materials was measured between 15K and 150K for the various concentrations of Ba and the phonon thermal conductivity was analyzed comparing with that of Nd_2–xCe_xCuO₄. The pretty large value for pure La₂CuO₄ was drastically diminished by substituting La by a small amount of Ba atoms especially at low temperatures. It was found that a new type of the phonon scattering center such as a two-level tunneling must be taken account of in order to explain the observed reduction.     

Effect of Absolute Configuration on the Optical and NMR Properties of Oligonucleotides Containing Benzo[a]Pyrene Adducts at N 6 of Deoxyadenosine

For oligonucleotide duplexes derived from trans opening of benzo[a]pyrene diol epoxides (BaP DEs) by the exocyclic N⁶-amino group of deoxyadenosine (dA), the hydrocarbon is intercalated toward the 5′-end of the modified strand when the configuration at the site of attachment of the base to the hydrocarbon (C-10) is R, and toward the 3′-end when this configuration is S. In oligonucleotide 11-mer duplexes modified by BaP DE-1 (benzylic 7-OH and epoxide oxygen cis) and DE-2 (7-OH and epoxide oxygen trans), as well as 7,8,9,10-tetrahydro BaP 9,10-epoxide, 10R adducts had consistently higher (5–9d°C) T_m values than the corresponding 10S adducts. Dodecamer duplexes from the HPRT gene with trans opened 10S (but not those with 10R) BaP DE-2 adducts at either of two adjacent dA residues exhibited blue shifts at ～350 nm at temperatures well below the T_m. We propose that these blue shifts result from a conformation in which the hydrocarbon is not stacked with the DNA bases.     

The effect of lutein supplementation on visual fatigue: A psychophysiological analysis

We used psychophysiological technology to examine the effect of an oral supplement, a combination of lutein, zeaxanthin and blackcurrant extract (LUT), on visual fatigue, within the context of a randomized, double-blind, placebo-controlled cross-over trial. The LUT supplement and placebo samples were randomly assigned to thirteen participants, who took the samples for two LUT (and vice versa) for another 2 week. Each participant completed visual proof reading tasks for 2 h during each of four testing sessions. Saccade tests were administered before and after the proof reading task, during which the participants moved their eyes back and forth between two targets positioned in the center of two checkerboards. We recorded EEG, EOG, heart rate, and facial muscle potential/performance during the saccade tests. Blood pressure was measured and subjective fatigue and stress scores were collected before and after the proof reading task. We averaged EEG starting at saccade offset in order to analyze eye fixation related potentials (EFRP). Our results suggested that the proof reading task induced visual fatigue. An analysis of EFRP and other psychophysiological data revealed significant differences between the LUT and placebo conditions. These results suggest that supplementation with LUT could help to reduce symptoms of visual fatigue.     

Radiation-induced polymerization of ethylene in pilot plant. III. Heavy-phase recycling process

Radiation-induced polymerization of ethylene using aqueous tert-butyl alcohol as medium was carried out in a large-scale pilot plant with a 50-liter central source-type reactor at a pressure of 105 to 395 kg/cm², temperature of 30° to 80°C, mean dose rate of 4.5 × 10⁴ to 1.9 × 10⁵ rads/hr, ethylene feed rate of 5.5 to 23.5 kg/hr, and medium feed rate of 21 to 102 l./hr. The space–time yield and molecular weight of the polymer were in the range of 4.7 to 16.8 g/l.-hr and 1.3 × 10⁴ to 8.9 × 10⁴, respectively. The space–time yield and molecular weight increased with mean residence time at 30°C, whereas at 80°C they became almost independent of the time. The space–time yield increased with pressure and dose rate, slightly decreased with temperature, and was maximum at ethylene molar fraction of 0.5. The polymer molecular weight increased with pressure and ethylene molar fraction, and decreased with dose rate and temperature. The total amount of deposited polymer on the reactor wall, source case wall, and scraping blades was usually less than 1 kg, which was negligibly small for the analysis of polymerization. Continuous discharge of the polymer slurry and production of fine-powder polyethylene were successfully carried out. In the central source-type reactor, a dose rate of 1.9 × 10⁵ rads/hr was obtained with a ⁶⁰Co source of ca. 12 kCi.     

Geology and fluid chemistry of the Fushime geothermal field, Kyushu, Japan

The Fushime geothermal field is located in a depression close to the coast line. The system is characterized by very high reservoir temperature (>350°C), and a high salinity production fluid. Geological analysis shows that the main reservoir in this field occurs in a fractured zone developed around a dacite intrusion located in the center of the field. High permeability zones recognized by drilling data are found to be associated with fault zones. One of these zones is clearly associated with a NW–SE trending andesite dike swarm which was encountered in some wells.Alteration in the system can be divided into four zones, in order of increasing temperature, based on calcium–magnesium aluminosilicate mineral assemblages: i.e., the smectite, transition, chlorite and epidote zones. The feed zone is located in the chlorite and epidote zones, which can be further divided into three sub-zones according to their potassium or sodium aluminosilicate mineralogy, from the center of the discharge zone: K-feldspar–quartz, sericite–quartz, and albite–chlorite zones.Chloride concentration of the sea-water is 19,800 mg/l, and Br/Cl mole ratio is 1.55. Based on geochemical information, the reservoir chloride concentration of this field ranges from 11,600 to 22,000 mg/kg. The Clres (Cl in reservoir), Br/Cl ratios and stable isotope data indicate that the Fushime geothermal fluid originated from sea-water and is diluted by ground water during its ascent. Some fluids produced from geothermal wells show low pH (about 4). It is thought that sulfide mineral (PbS, ZnS) precipitation during production produces this acidic fluid.     

Anaerobic Biodegradation Tests of Poly(lactic acid) under Mesophilic and Thermophilic Conditions Using a New Evaluation System for Methane Fermentation in Anaerobic Sludge

Anaerobic biodegradation tests of poly(lactic acid) (PLA) powder were done at the thermophilic (55 °C) and mesophilic temperature (35 °C) under aquatic conditions [total solid concentrations of the used sludge were 2.07% (at 55 °C) and 2.24% (at 35 °C)] using a newly developed evaluation system. With this system, the evolved biogas is collected in a gas sampling bag at atmospheric pressure. This method is more convenient than using a pressure transducer or inverted graduated cylinder submerged in water. PLA was degraded about 60% in 30 days, about 80% in 40 days and about 90% in 60 days at 55 °C. On the other hand, the PLA degradation started in 55 days at 35 °C and degradation rate was much slower than at 55 °C.     

Distractor devaluation effect in the attentional blink: Direct evidence for distractor inhibition.

When two targets (T1 and T2) are embedded in rapid serial visual presentation (RSVP), T2 is often missed (attentional blink, AB) if T2 follows T1 by less than 500 ms. Some have proposed that inhibition of a distractor following T1 contributes to the AB, but no direct evidence supports this proposal. This study examined distractor inhibition by assessing a distractor devaluation effect where inhibited items were evaluated less positively than controls. Experiments 1 and 2 showed that a distractor presented just after T1 was evaluated less favorably when T2 was misidentified, independently of stimulus characteristics. Experiment 3 produced distractor devaluation in T2 incorrect trials when the evaluated distractor was the second item after T1. In contrast, a distractor presented before T1 was not devaluated (Experiment 4). Experiment 5 demonstrated that participants could not recognize presented distractors after an RSVP task, rejecting the possibility that memorized distractors were devalued. Results show a relationship between the devaluation of distractors following T1 and the AB, providing the first direct evidence of the distractor inhibition during the AB. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Kink and power saturation of 660-nm AlGaInP laser diodes

We analyze kink and power saturation phenomena of high power 660-nm laser diodes for DVD-R/RW experimentally. Power-current (P-I) and voltage-current (V-I) characteristics of laser diodes with different cavity lengths were measured. Using these results and thermal resistances, temperature rises caused by self-heating (/spl Delta/T) and the dependence of slope efficiencies on the temperature rise (Se-/spl Delta/T) were calculated. The slope efficiencies decreased linearly with /spl Delta/T and their gradients showed the same value regardless of the cavity length, while they had no systematic dependence on the current. The kinks occurred at the same /spl Delta/T of 30/spl deg/C regardless of the cavity length, while they occurred at different currents. These results indicate that the temperature rise caused by the self-heating is a key parameter for the kink and the saturation power. A method is proposed to calculate the kink and the saturation power using the gradient (Se-/spl Delta/T) and the kink temperature.     

Broadband four-wave mixing generation in short optical fibres

Several advantages of using a short length of fibre to generate broadband four-wave mixing are proposed and verified using wavelength conversion experiments for different lengths of a previously developed high-nonlinearity fibre with a nonlinear coefficient of 13.8 W^-1 km^-1. Consequently, 91.3 nm broadband simultaneous wavelength conversion is demonstrated using a 100 m long section of the developed fibre     

Long-term evaluation of combined antihypertensive therapy with lisinopril and a thiazide diuretic in patients with essential hypertension

For the treatment of hypertension, the combination of an angiotensin-converting enzyme (ACE) inhibitor and a thiazide diuretic is supported by multiple lines of evidence, because these drugs have synergistic action and are expected to cancel out each other's adverse side effects. However, the long-term outcome of this combination antihypertensive therapy is not entirely clear. In the present multicenter open trial, we investigated the long-term efficacy and safety of combined antihypertensive therapy with an ACE inhibitor, lisinopril, and a thiazide diuretic, trichlormethiazide. A total of 466 patients with essential hypertension were treated with lisinopril alone (monotherapy group, n = 360) or with a combination of lisinopril with trichlormethiazide (combination therapy group, n = 106) for 1 year. The average blood pressure was effectively lowered to below 150/90 mmHg in both the monotherapy and the combination therapy groups throughout the study period. The average maintenance dose of lisinopril was lower when combined with thiazide than when given alone (9.8 vs. 11.5 mg/day, p < 0.001). Dry cough was the major side effect of lisinopril; no severe adverse effects were observed. The incidence of cough was not significantly different between the monotherapy group (13.1%) and the combination therapy group (11.3%). The increase in serum potassium observed in the monotherapy group was reversed by the concurrent use of the thiazide diuretic in the combination therapy group. Fasting blood glucose was significantly reduced in the monotherapy group; the reduction observed in the combination therapy group was not significant. Thus, the present results provide useful information as to the effectiveness and safety of combined antihypertensive therapy with lisinopril and a thiazide in comparison with monotherapy with lisinopril.