Hydrogen production by combining two types of photosynthetic bacteria with different characteristics

The double-layer photobioreactor using two types of photosynthetic bacteria, Rhodobacter sphaeroides RV and its reduced-pigment mutant, MTP4, was developed for efficient hydrogen production. The two types of bacteria had different characteristics on light energy, hydrogen production rate and conversion efficiency. MTP4 produced hydrogen more efficiently under high light conditions and RV did so under low light conditions. Illuminated light toward the surface of a photobioreactor quasi-exponentially declines as it penetrates into the reactor. When two types of bacteria were placed using the developed reactor according to this light distribution, the hydrogen production rate reached 3.64 l/m²/h at a light intensity of 500 W/m² in 24 h and the conversion efficiency of light energy to hydrogen was 2.18%. These values were 33% higher than those of only using RV. The low light in the deep part of the reactor was utilized efficiently, resulting in a higher hydrogen production rate.     

Neutronic and thermodynamic feasibility of UF6-NpF6 fueled transmutation reactor

Transmutation of neptunium, which is contained in radioactive wastes discharged from nuclear reactors, was investigated as a substitutional method for geologic disposal. We proposed a transmutation reactor fueled with a mixture of gaseous ²³³UF₆ and ²³⁷NpF₆. Neutronic and thermodynamic analysis of the reactor revealed the feasibility of the concept. The reactor has two principal advantages: (1) use of the fuel gas enables on-line reprocessing, (2) ²³⁷Np can be transmuted by a high neutron flux. Our calculation indicated that the transmutation rate of ²³⁷Np was 335 g/year/MW_th, which is much larger than the annual yield of ²³²Np in PWR (6.19 g/year/MW_th).     

Monte Carlo uncertainty quantification of the effective delayed neutron fraction

The applicability of Monte Carlo techniques, namely the Monte Carlo sensitivity method and the random-sampling method, for uncertainty quantification of the effective delayed neutron fraction β_eff is investigated using the continuous-energy Monte Carlo transport code, MCNP, from the perspective of statistical convergence issues. This study focuses on the nuclear data as one of the major sources of β_eff uncertainty. For validation of the calculated β_eff, a critical configuration of the VENUS-F zero-power reactor was used. It is demonstrated that Chiba's modified k-ratio method is superior to Bretscher's prompt k-ratio method in terms of reducing the statistical uncertainty in calculating not only β_eff but also its sensitivities and the uncertainty due to nuclear data. From this result and a comparison of uncertainties obtained by the Monte Carlo sensitivity method and the random-sampling method, it is shown that the Monte Carlo sensitivity method using Chiba's modified k-ratio method is the most practical for uncertainty quantification of β_eff. Finally, total β_eff uncertainty due to nuclear data for the VENUS-F critical configuration is determined to be approximately 2.7% with JENDL-4.0u, which is dominated by the delayed neutron yield of ²³⁵U.     

Characterization of the Key Aroma Compounds of Citrus flaviculpus Hort. ex Tanaka by Aroma Extraction Dilution Analysis

ABSTRACT: The key aroma compounds were identified in Citrus flaviculpus Hort. ex Tanaka (ki-mikan) by using aroma extraction dilution analysis (AEDA) and the sniff test. Ki-mikan peel oil was extracted by cold-pressing. The highest flavor dilution (FD) factor was found for limonene. β-Phellandrene, carvacrol, spathulenol, camphene, elemol, (+)- trans -limonene oxide, and tetradecane showed higher relative flavor activity. Results of the sniff test of the original essential oil and its oxygenated fraction revealed that tetradecane, linalool, and α-terpineol were regarded as the key aroma compounds of ki-mikan peel oil. A diluted solution of linalool and α-terpineol of 3 ppm gave a ki-mikan-like flavor, while a higher concentration near 100 ppm of tetradecane tended to produce a fresh and fruity aroma note similar to ki-mikan flavor.     

Advanced Method for Measuring Proteinase A in Beer and Application to Brewing*

Proteinase A, excreted from yeast cells into beer during fermentation in the brewing process, has been shown to degrade foam-active proteins and to decrease foam stability. In order to improve the measurement of this enzyme in beer, a new fluorescent peptide, MOCAc-Ala-Pro-Ala-Lys-Phe-Phe-Arg-Leu-Lys (Dnp)-NH₂, was synthesised and applied to the accurate and rapid estimation of proteinase A in commercial beer and fermenting wort. This novel substrate is several hundred times more sensitive to proteinase A than other previously reported synthetic substrates or native protein substrates. The concentration of proteinase A in beer is closely related to foam stability and proteinase A activity was found to increase gradually during fermentation. The concentration of proteinase A excreted from yeast cells is also closely related to the vitality of pitching yeast cells. This new method was successfully applied to the evaluation of yeast vitality and the development of optimum yeast handling procedures.     

Performance Evaluation of Magnetostrictive Small Wind Turbines Using Fe–Co Alloy–Based Clad Sheets

In this study, the Fe–Co alloy is combined with cobalt ferrite (CoFe₂O₄) and nickel (Ni) to form Fe–Co/CoFe₂O₄ and Fe–Co/Ni clad sheets and their energy-harvesting performance is evaluated. The Fe–Co/CoFe₂O₄ clad sheet exhibits an output voltage of 4.229 mV and an output power of 6.89 nW at a wind speed of 10 m s⁻¹. The energy-harvesting performance of both these clad sheets cannot be quantitatively compared owing to their different thicknesses, which result in varying volume and distance from the neutral plane. Nevertheless, the values of output voltage and power for Fe–Co/CoFe₂O₄ are higher than those for Fe–Co/Ni (2.107 mV and 0.294 nW).     

Structure-activity relationships of non-peptide vasopressin V1a antagonists: 1-(1-multi-substituted benzoyl 4-piperidyl)-3,4-dihydro-2(1H)-quinolinones

During our systematic studies on the arginine vasopressin receptor V1a-antagonistic activity of 1-(1-benzoyl substituted 4-piperidyl)-3,4-dihydro-2(1H)-quinolinones, we found a general substituent effect on the benzene ring. Hydrogen-bonding ability at the ortho position was especially important for enhancement of the affinity of multi-substituted analogs. Details of the syntheses and structure-activity relationships for this series are presented.     

A 78-year-old man with young onset parkinsonism and sudden death

We report a right-handed 78-year-old man with early onset parkinsonism. The patient had an onset of micrographia at 23 years of the age in 1939. Seven years later he started to drag his right foot, and at 38 years of age, he walked with small steps with festination. Tremor was also present in his right hand. His daily life was independent as a otorhinolaryngologist. He visited our clinic on March 24, 1977 when he was mentally sound and showed mild parkinsonism consisting of masked face, stooped posture, small step gait, bradykinesia, and right side dominant rigidity and tremor. He showed good response to trihexyphenidyl and amantadine HCl. Two month later, he developed dyskinesia and some worsening of parkinsonism, and was admitted to our hospital for the first time. He was treated with 400 to 600 mg/day of levodopa/ carbidopa. He showed marked improvement, however, dyskinesia remained in his mouth. He was doing well until 77 years of age (June of 1993) when he developed hallucination and motor fluctuations. He was admitted again to our hospital on June 22, 1993. On admission, he was alert and appeared mentally sound. However, Hasegawa dementia scale was 18/30. Upward gaze was slightly restricted (3/5). Voice was somewhat small but no masking was noted. His posture was stooped and the gait was of small step. Dyskinesia was noted during walk. No rigidity nor tremor was noted. Deep tendon reflexes were lost but no sensory loss or motor weakness was noted. Routine laboratory studies were unremarkable. A cranial CT scan revealed only mild to moderate cortical atrophy. Motor and sensory conduction velocities were within normal limits, however, motor action potentials could not be obtained with stimulation to the right common peroneal nerve. He was treated with 600 mg/day of levodopa with carbidopa, 100 mg of amantadine HCl, 300 mg of Dops, and 25 mg of tiapride. He continued to show motor fluctuations, and was discharged on July 23, 1993. Since then his motor functions had become progressively worse with frequent falls, but he was still able to walk without support. On October 3 of 1994, he went to bed as usual. On the next morning, he was found dead in his bed at 9: 30. The patient was discussed in neurological CPC, and the chief discussant arrived at the conclusion that the patient had young-onset Parkinson's disease with Lewy bodies in the substantia nigra. Opinions were divided between Parkinson's disease and Lewy body negative young onset parkinsonism. Postmortem examination revealed obstruction of the trachea by aspirated foods, and the cause of death appeared to have been suffocation by the foods. Macroscopically, the external appearance of the brain was unremarkable except for slight frontal atrophy. The substantia nigra showed depigmentation in the lateral part, but the pigmentation of the medial part was well preserved. Upon histologic examination, the number of pigmented neurons in the dorsomedial part was well preserved. In the lateral part, pigmented neurons were well preserved in the dorsal area, however, in the ventral area, only non-pigmented neurons were seen; they appeared to be neurons in the pars reticulata. No gliosis was seen in any of the nigral areas. No Lewy bodies were seen in the remaining neurons. So-called immature neurons with rounded shape without neuromelanin could not be detected. The locus coeruleus neurons were well preserved. The putamen and the other basal ganglia structures were also intact. Slight myelin pallor was noted in the subcortical white matter, however, otherwise cerebral cortices were normal. The histology of this patient is unique in that only the ventrolateral part of the substantia nigra showed abnormal finding consisting of lack of pigmented neurons without gliosis. It is not clear whether the nigral change represents degeneration or a congenital "hypoplasia'. To our knowledge, such a unique pathology of the substantia nigra has not been reported in the literature. Our patient ma