On caustics of submanifolds and canal hypersurfaces in Euclidean space

We investigate a relationship between the caustics of a submanifold of general dimension and of a canal hypersurface of the submanifold in Euclidean space. As a consequence, these caustics are the same. Moreover, induced Lagrangian immersion germs are Lagrangian equivalent under a suitable condition. In order to show the results, we use the theory of Lagrangian singularity and of Legendrian singularity.     

δ13C and δ15N values in scales of Micropterus salmoides largemouth bass as a freshwater environmental indicator

We have investigated the effectiveness of using the Micropterus salmoides largemouth bass, which is a top predator found throughout the world, as the index of a hydrosphere environment and its food chain. To this end, we used stable carbon and nitrogen isotope analysis (SIA). Largemouth bass were collected from eight dam reservoirs and two ponds in Toyama Prefecture, Japan. Toyama is located in central Japan and features a variety of distinct geographical environments, a result of the 3000-m elevation that changes over short distances, and abundant water systems. The mean δ(13)C and δ(15)N values for the lipid-extracted muscle of largemouth bass from all sampling locations showed large variability, but there were only small standard deviations at each sampling location. The isotope ratios for largemouth bass express the characteristics of each investigated hydrosphere environment and food chain. A very high correlation (δ(13)C: Y(scale) = 0.96 X(muscle) + 1.58, R(2) = 0.98, δ(15)N: Y(scale) = 0.92 X(muscle) - 1.15, R(2) = 0.95) of SIA values was found between largemouth bass scales and lipid-extracted muscles, which suggests that the more easily analyzed scales are useful as SIA samples for the monitoring and comparison of hydrosphere environments throughout the world.     

Fields of stress and electric displacement produced by dislocations and disclinations in three-dimensional,anisotropic, elastic,and piezoelectric media. II. Infinite straight dislocation and Frank disclination

The fields of stress and electric displacement caused by infinitely extended straight dislocations and Frank disclinations are deduced from the author's statements for the fields caused by a continuous distribution of dislocations and disclinations (S. Minagawa, Phil. Mag. 84 2229 (2004)). The multiple integrals in the original statements are converted into functions of space coordinates. Cauchy's theorem plays an important part. The improper integral that appears in computations of the fields around a Frank disclination is interpreted as its finite part by Hadamard. Examples are the fields around an infinite straight defect in caesium copper chloride, as well as those in gallium arsenide. The contours and zero lines are plotted to illustrate the fields caused by a dislocation and a disclination dipole.     

Development of a rapid process monitoring method for dry-coated tableting process by using near-infrared spectroscopy

A nondestructive transmittance near-infrared (NIR) method for detecting off-centered cores in dry-coated (DC) tablets was developed as a monitoring system in the DC tableting process. Caffeine anhydrate was used as a core active pharmaceutical ingredient (API), and DC tablets were made by the direct compression method. NIR spectra were obtained from these intact DC tablets using the transmittance method. The reference assay was performed with HPLC. Calibration models were generated by partial least squares (PLS) regression and principal component regression (PCR) utilizing external validations. Hierarchical cluster analysis (HCA) of the results confirmed that NIR spectroscopy correctly detected off-centered cores in DC tablets. We formulated and used the Centering Index (CI) to evaluate the precision of core alignment and generated an NIR calibration model that could correctly predict this index. The principal component (PC) 1 loading vector of the final calibration model indicated that it could specifically detect the misalignment of tablet cores. The model also had good linearity and accuracy. The CIs of unknown sample tablets predicted by the final calibration model and those calculated through the HPLC analysis were closely parallel with each other. These results demonstrate the validity of the final calibration model and the utility of the transmittance NIR spectroscopic method developed in this study as a monitoring system in DC tableting process.     

Alternative approach to the design of thermosensitive polymers: The addition of hydrophobic groups to the ends of hydrophilic polyether

We synthesized thermosensitive polymers by adding hydrophobic groups to the ends of a hydrophilic polyether, poly(ethylene oxide‐co‐propylene oxide). The cloud points of the polymers were controlled by the molecular weight of the polyether and the kind of hydrophobic end group. The polymers showed relatively sharp phase transitions, as observed by turbidimetry. The order of the cloud points of the polymers with various end groups did not follow that of the critical micelle concentrations of the polymers determined with fluorescence measurements with pyrene as a probe. The cloud points of the polymers linearly decreased with increasing concentrations of salts (Na₂SO₄ and Na₃PO₄). The slopes of the linear lines were almost constant, regardless of the kind of hydrophobic group and the molecular weight of the polyether. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1007–1013, 2005     

Alternative protocol for oxidation in water: an effective epoxidation system promoted by the combination of Oxone and an amphiphilic ketone

Epoxidation of cyclooctene and other alkenes with Oxone^® was promoted effectively in an aqueous micellar solution of an amphiphilic ketone, which was easily derived from hepta(ethylene glycol) monodecyl ether.     

Bifurcations of ordinary differential equations of Clairaut type

We classify a one-parameter family of Clairaut-type equations. In order to pursue the classification, we use legendrian singularity theory and the notion of one-parameter complete legendrian unfoldings which induces a special class of divergent diagrams of map germs which are called one-parameter integral diagrams. Our normal forms are represented by one-parameter integral diagrams.     

Polymerizable Tautomers. VII. Radical Copolymerization of Ethyl 3-oxo-4-Pentenoate and Ethyl 4-Methyl-3-oxo-4-Pentenoate with Methyl Methacrylate

Abstract

Ethyl 3-oxo-4-pentenoate (EAA) and ethyl 4-methyl-3-oxo-4-pentenoate (EMAA) exhibit the coexistence of the ketonic and enolic forms in most organic solvents. Radical copolymerizations of EAA and EMAA with methyl methacrylate (MMA) were carried out at 60 °C in various solvents, and monomer reactivity ratios were estimated. There are minor solvent effects on monomer reactivity ratios r_MMA in both EAA/MAA and EM A A/MM A systems. On the other hand, r_EAA and r_MMA values greatly change with the solvent: The values decrease with an increase in the ketonic fraction of the polymerizable tautomers (EAA and EMAA). Regression analysis of the monomer reactivity ratios with the solvatochromic parameters reveals that polarity of the solvent is the major factor governing the relative reactivity.     

Synthesis of insoluble polystyrene‐supported flavins and their catalysis in aerobic reduction of olefins

2′,4′‐p‐Vinylbenzylideneriboflavin ( 2′,4′‐PVBRFl ) was prepared as a flavin‐containing monomer and copolymerized with divinylbenzene and styrene or its p‐substituted derivatives such as 4‐acetoxystyrene, 4‐vinylbenzyl alcohol, and 4‐vinylbenzoic acid to give the corresponding non‐functionalized and functionalized PS‐DVB‐supported flavins PS(H)‐DVB‐Fl , PS(OAc)‐DVB‐Fl , PS(CH₂OH)‐DVB‐Fl , and PS(COOH)‐DVB‐Fl , respectively. PS(OH)‐DVB‐Fl was also prepared by hydrolysis of PS(OAc)‐DVB‐Fl under basic conditions. These novel flavin‐containing insoluble polymers exhibited characteristic fluorescence in solid state, except PS(OH)‐DVB‐Fl , and different catalytic activities in aerobic reduction of olefins by in situ generated diimide from hydrazine depending on their pendant functional group. For example, PS(H)‐DVB‐Fl was found to be particularly effective for neutral hydrophobic substrates, which could be readily recovered by a simple filtration and reused more than 10 times without loss in catalytic activity. On the other hand, PS(OH)‐DVB‐Fl and PS(COOH)‐DVB‐Fl proved to be highly active for phenolic substrates known to be less reactive in the reaction with conventional non‐supported flavin catalysts. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 1706–1713     

Chemical pressure effect on the superconductor MgCNi3

In order to investigate the positive and negative pressure effects on superconducting properties for MgCNi₃, chemical pressure was applied by means of Zn-doping to Mg site (Mg_1−xZn_xCNi₃) and by substituting Mg with Cd (CdCNi₃). The lattice constant decreases (increases) with increasing Zn (Cd) content. In the magnetic measurements, superconducting transition temperature (T_c) is decreasing with increasing Zn content and disappears at x > 0.3. While for CdCNi₃, T_c also decreases down to 3.4 K. The result seems not to be fully understandable in the case of CdCNi₃ since T_c seems to rise owing to the increase of density of states at Fermi energy caused by lattice expansion.