oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2020 ( 3 )

2019 ( 8 )

2018 ( 15 )

2017 ( 22 )

Custom range...

Search Results: 1 - 10 of 2394 matches for " Kenji Okitsu "
All listed articles are free for downloading (OA Articles)
Page 1 /2394
Display every page Item
Catalytic Technologies for Biodiesel Fuel Production and Utilization of Glycerol: A Review
Le Tu Thanh,Kenji Okitsu,Luu Van Boi,Yasuaki Maeda
Catalysts , 2012, DOI: 10.3390/catal2010191
Abstract: More than 10 million tons of biodiesel fuel (BDF) have been produced in the world from the transesterification of vegetable oil with methanol by using acid catalysts (sulfuric acid, H 2SO 4), alkaline catalysts (sodium hydroxide, NaOH or potassium hydroxide, KOH), solid catalysts and enzymes. Unfortunately, the price of BDF is still more expensive than that of petro diesel fuel due to the lack of a suitable raw material oil. Here, we review the best selection of BDF production systems including raw materials, catalysts and production technologies. In addition, glycerol formed as a by-product needs to be converted to useful chemicals to reduce the amount of glycerol waste. With this in mind, we have also reviewed some recent studies on the utilization of glycerol.
The Corrosion Behavior of Ni3Al/Ni3V Two-Phase Intermetallic Compounds in Various Acidic Solutions
Gadang Priyotomo,Hideyuki Momono,Sanat Wagle,Kenji Okitsu,Akihiro Iwase,Yasuyuki Kaneno,Rokuro Nishimura,Takayuki Takasugi
International Journal of Corrosion , 2012, DOI: 10.1155/2012/626240
Abstract: The corrosion behavior of the Ni3Al/Ni3V two-phase intermetallic compounds with and without minor elements (Nb, Co, and Cr) to be composed of L12 phase (Ni3Al) and a mixed phase of L12 (Ni3Al) and D022 (Ni3V) has been investigated by using an immersion test in 0.5?kmol/m3 HCl, H2SO4, and HNO3 solutions. The surface morphology was observed before and after the immersion test by scanning electron microscope (SEM). The results were compared to those of the L12 single-phase Ni3(Si,Ti) and austenitic stainless steel type 304. In all acidic solutions, preferential dissolution of ( ) phase was found in Ni3Al/Ni3V, but no intergranular attack, whereas the attacks took place on Ni3(Si,Ti). The Ni3Al/Ni3V showed a higher corrosion resistance in HCl solution and a lower resistance in HNO3 solution than Ni3(Si,Ti) and type 304. The addition of the minor elements enhanced corrosion resistance in HNO3 solution, but not clearly in HCl and H2SO4 solutions. In HCl and H2SO4, their weight losses during the immersion test were almost the same. 1. Introduction Recently, Ni-Al-V intermetallic compounds with a two-phase microstructure of Ni3Al (L12) and Ni3V (D022) phases have been developed by Takasugi et al. [1–13] and are confirmed to exhibit a highly coherent interface between these constituent phases. They have superior mechanical properties (i.e., high creep rapture life, high hardness, low thermal expansion, and better thermal conductivity) and also have high tensile strength and fracture toughness over a broad range of temperature in comparison with those of Inconel 750, Inconel 718 and Hastelloy [1–13]. Therefore, the Ni3Al/Ni3V two-phase intermetallic compounds are a candidates as materials in land-based, marine-based, and aero-gas turbine industries (turbine blade), high strength nut and bolt, and high temperature bearing or high temperature tool [8, 9, 14]. However, many studies revealed that the intermetallic compounds containing aluminum are very susceptible to hydrogen embrittlement [15–18], where hydrogen embrittlement takes place with permeation of atomic hydrogen formed by corrosion reaction into the compounds. Hence, to suppress this environmental embrittlement a small amount of boron was added to these compounds. However, it was reported that the boron segregation at grain boundaries became the preferential dissolution site and led to the intergranular attack in the L12 single-phase Ni3(Si,Ti) [19]. Furthermore, Ni base intermetallic compounds such as single-phase Ni3(Si,Ti) have attractive properties for high-temperature structural material (e.g., high
The cutting construction of toric symplectic and contact manifolds
Yushi Okitsu
Mathematics , 2013,
Abstract: We introduce the cutting construction of possibly non-compact symplectic toric manifolds, in particular, toric symplectic cones that correspond to a weakly convex good cone. Since the symplectization of a toric contact manifold is a toric symplectic cone, we can also construct toric contact manifolds that correspond to a weakly convex good cone by the cutting construction. (Note that these toric contact manifolds can not be constructed by Delzant construction.) We further prove there are no toric Sasakian structures on these contact manifolds. From this, contact toric manifolds of toric K-contact type are of toric Sasakian type.
A comparison of a patient-rated visual analogue scale with the Liebowitz Social Anxiety Scale for social anxiety disorder: A cross-sectional study  [PDF]
Hiromi Okitsu, Jitsuki Sawamura, Katsuji Nishimura, Yasuto Sato, Jun Ishigooka
Open Journal of Psychiatry (OJPsych) , 2014, DOI: 10.4236/ojpsych.2014.41010
Abstract:

Introduction: The Liebowitz Social Anxiety Scale (LSAS), used to assess the severity of social anxiety disorder (SAD), requires considerable effort and time to complete. The aims of this study were: 1) to investigate whether a visual analogue scale (VAS) could be linear with the LSAS and substitute for the LSAS, 2) to relate such a VAS instrument to patient demographics. Methods: Fifty SAD patients were assessed using the LSAS and VAS instruments completed by both patients and doctors at the same session. We then drew distributions and calculated the Spearman’s ρ and κ coefficient values (divided at the median for each scale) between patient and doctor assessments. Next, each pair among the scores for the LSAS, the patient VAS and the doctor VAS was compared using Wilcoxon rank sum tests according to patient life profile data. Results: Scatter plots of pairs of scores were obtained. Spearman’s ρ was 0.661 between the LSAS and the patient VAS, 0.461 between the LSAS and the doctor VAS, and 0.494 between VAS scores of patients and doctors. The κ coefficients were 0.501 between the LSAS and patient VAS, 0.251 between the LSAS and doctor VAS, and 0.425 between patient VAS and doctor VAS (for all six, p < 0.001). The Wilcoxon rank sum tests indicated a significant difference between the groups with/ without “employment” (LSAS, patient/doctor VAS), with/without “graduation from junior college/university” (doctor VAS) (p < 0.05) and with/without marital history (the age of first consultation) (p < 0.01). Conclusions: A patient VAS may substitute for the LSAS and offer the versatility necessary to capture patient states and life profiles.

Evolution based on genome structure: the “diagonal genome universe”  [PDF]
Kenji Sorimachi
Natural Science (NS) , 2010, DOI: 10.4236/ns.2010.210137
Abstract: The ratios of amino acid to the total amino acids and those of nucleotides to the total nucleotides in genes or genomes are suitable indexes to compare whole gene or genome characteristics based on the large number of nucleotides rather than their sequences. As these ratios are strictly calculated from nucleotide sequences, the values are independent of experimental errors. In the present mini-review, the following themes are approached according to the ratios of amino acids and nucleotides to their total numbers in the genome: prebiotic evolution, the chronological precedence of protein and codon formations, genome evolution, Chargaff’s second pa- rity rule, and the origins of life. Amino acid formation might have initially occurred during pre- biotic evolution, the “amino acid world”, and amino acid polymerization might chronologically precede codon formation at the end of prebiotic evolution. All nucleotide alterations occurred synchronously over the genome during biolo- gical evolution. After establishing primitive lives, all nucleotide alterations have been governed by linear formulae in nuclear and organelle genomes consisting of the double-stranded DNA. When the four nucleotide contents against each individual nucleotide content in organelles are expressed by four linear regression lines representing the diagonal lines of a 0.5 square – the “Diagonal Genome Universe”, evolution obeys Chargaff’s second parity rule. The fact that linear regression lines intersect at a single point su- ggests that all species originated from a single life source.
Evolution from Primitive Life to Homo sapiens Based on Visible Genome Structures: The Amino Acid World  [PDF]
Kenji Sorimachi
Natural Science (NS) , 2009, DOI: 10.4236/ns.2009.12013
Abstract: It is not too much to say that molecular biology, including genome research, has progressed based on the determination of nucleotide or amino acid sequences. However, these ap-proaches are limited to the analysis of relatively small numbers of the same genes among spe-cies. On the other hand, by graphical presenta-tion of the ratios of the numbers of amino acids present to the total numbers of amino acids presumed from the target gene(s) or genome or those of the numbers of nucleotides present to the total numbers of nucleotides calculated from the target gene(s) or genome, we can readily draw conclusions from extraordinarily huge data sets integrated by human intelli-gence. 1) Assuming polymerization of amino acids or nucleotides in a simulation analysis based on a random choice, proteins were formed by simple amino acid polymerization, while nucleotide polymerization to form nucleic acids encoding specific proteins needed certain specific control. These results proposed that protein formation chronologically preceded codon formation during the establishment of primitive life forms. In the prebiotic phase, amino acid composition was a dominant factor that determined protein characteristics; the “Amino Acid World”. 2) The genome is constructed homogeneou- sly from putative small units displaying similar codon usages and coding for similar amino acid compositions; the unit is a gene assembly en-coding 3,000 - 7,000 amino acid residues and this unit size is independent not only of genome size, but also of species. 3) In codon evolution, all nucleotide alterna-tions are correlated, not only in coding regions, but also in non-coding regions; the correlations can be expressed by linear formulas; y = ax + b, where “y” and “x” represent nucleotide con-tents, and “a” and “b” are constant. 4) The basic pattern of cellular amino acid compositions obtained from whole cell lysates is conserved from bacteria to Homo sapiens, and resembles that calculated from complete genomes. This basic pattern is characterized by a “star-shape” that changes slightly among species, and changes in amino acid composi-tion seem to reflect biological evolution. 5) Organisms can essentially be classified according to two codon patterns. Biological evolution due to nucleotide sub-stitutions can be expressed by simple linear formulas based on mathematical principles, while natural selection must affect species pre- servation after nucleotide alternations. There-fore, although Darwin’s natural selection is not directly involved in nucleotide alternations, it contributes obviously to the
Codon evolution in double-stranded organelle DNA: strong regulation of homonucleotides and their analog alternations  [PDF]
Kenji Sorimachi
Natural Science (NS) , 2010, DOI: 10.4236/ns.2010.28106
Abstract: In our previous study, complete single DNA strands which were obtained from nuclei, chloroplasts and plant mitochondria obeyed Chargaff’s second parity rule, although those which were obtained from animal mitochondria deviated from the rule. On the other hand, plant mitochondria obeyed another different rule after their classification. Complete single DNA strand sequences obtained from chloroplasts, plant mitochondria, and animal mitochondria, were divided into the coding and non-coding regions. The non-coding region, which was the complementary coding region on the reverse strand, was incorporated as a coding region in the forward strand. When the nucleotide contents of the coding region or non-coding regions were plotted against the composition of the four nucleotides in the complete single DNA strand, it was determined that chloroplast and plant mitochondrial DNA obeyed Chargaff’s second parity rule in both the coding and non-coding regions. However, animal mitochondrial DNA deviated from this rule. In chloroplast and plant mitochondrial DNA, which obey Chargaff’s second parity rule, the lines of regression for G (purine) and C (pyrimidine) intersected with regression lines for A (purine) and T (pyrimidines), respectively, at around 0.250 in all cases. On the other hand, in animal mitochondrial DNA, which deviates from Chargaff’s second parity rule, only regression lines due to the content of homonucleotides or their analogs in the coding or non-coding region against those in the complete single DNA strand intersected at around 0.250 at the horizontal axis. Conversely, the intersection of the two lines of regression (G and A or C and T) against the contents of heteronucleotides or their analogs shifted from 0.25 in both coding and non-coding regions. Nucleotide alternations in chloroplasts and plant mitochondria are strictly regulated, not only by the proportion of homonucleotides and their analogs, but also by the heteronucleotides and their analogs. They are strictly regulated in animal mitochondria only by the content of homonucleotides and their analogs.
Genomic data provides simple evidence for a single origin of life  [PDF]
Kenji Sorimachi
Natural Science (NS) , 2010, DOI: 10.4236/ns.2010.25065
Abstract: One hundred and fifty years ago, Charles Darwin’s on the Origin of Species explained the evolution of species through evolution by natural selection. To date, there is no simple piece of evidence demonstrating this concept across species. Chargaff’s first parity rule states that comple-mentary base pairs are in equal proportion across DNA strands. Chargaff’s second parity rule, in-consistently followed across species, states that the base pairs are in equal proportion within DNA strands [G ≈ C, T ≈ A and (G + A) ≈ (C + T)]. Using genomic libraries, we analyzed the extent to which DNA samples followed Chargaff’s second parity rule. In organelle DNA, nucleotide rela-tionships were heteroskedastic. After classifying organelles into chloroplasts and mitochondria, and then into plant, vertebrate, and invertebrate I and II mitochondria, nucleotide relationships were expressed by linear regression lines. All regression lines based on nuclear and organelle DNA crossed at the same point. This is a simple demonstration of a common ancestor across species.
A Comment on Reis  [PDF]
Kenji Miyazaki
Theoretical Economics Letters (TEL) , 2011, DOI: 10.4236/tel.2011.13019
Abstract: This note gives a counterexample on Reis [1]. Using a certain family of utility functions, this note not only gives a sharper representation than that of Reis but also demonstrates that interest rate inelastic money demand does not lead to superneutrality. This implies that superneutrality does not exist when uncerinty is introduced.
Prosody and Quantifier Float in Japanese  [PDF]
Kenji Yokota
Open Journal of Modern Linguistics (OJML) , 2013, DOI: 10.4236/ojml.2013.31011
Abstract: The paper investigates the information structure that licenses the Japanese floating numeral quantifier (FNQ) in terms of prosody and context from the point of view that the pitch reset on the FNQ affects the information structure and plays a crucial role in determining the interpretation of the FNQ. I will show that FNQ sentences are potentially ambiguous between an event-quantifier reading (i.e., a VP-related FNQ reading), and an object-quantifier reading (i.e., an NP-related FNQ reading) where such a reading is possible. The syntactic and semantic difference yields distinct prosodic phrasings (in accordance with information-structure) which contribute to the disambiguation of the two readings (and hence the grammaticality).
Page 1 /2394
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.