Development of a frequency-detuned interferometer as a prototype experiment for next-generation gravitational-wave detectors

We report on our prototype experiment that uses a 4-m detuned resonant sideband extraction interferometer with suspended mirrors, which has almost the same configuration as the next-generation, gravitational-wave detectors. We have developed a new control scheme and have succeeded in the operation of such an interferometer with suspended mirrors for the first time ever as far as we know. We believe that this is the first such instrument that can see the radiation pressure signal enhancement, which can improve the sensitivity of next-generation gravitational-wave detectors.     

An ultrasonic linear motor using ridge-mode traveling waves

A new type of ultrasonic linear motor is presented using traveling waves excited along a ridge atop a substrate. The ridge cross section was designed to permit only the fundamental mode to be excited during operation of the motor, with a Langevin transducer used as the source of vibration in this study. The ridge waveguide was first made of lossy media to avoid reflecting vibration energy back toward the vibration source, forming a traveling wave. A 5-mm-wide, 15-mm-tall rectangular acrylic ridge was used to move a slider placed upon it toward the vibration source, in opposition to the direction of the traveling wave transmitted along the waveguide ridge. Using a low-loss 3 x 6-mm aluminum rectangular ridge combined with a damper clamped onto the far end of the waveguide, similar results were obtained. To obtain bidirectional operation, the damper was replaced with a second Langevin transducer, giving a pair of transducers located perpendicularly to the ends of the ridge and driven with an appropriate phase difference. The moving direction of the slider was reversed by shifting this phase difference by about 180 degrees. With this simple configuration, it may soon be possible to fabricate a linear micromotor system on a silicon substrate or other semiconductor wafer adjacent to other electronic and optoelectronic devices.     

Decarboxylation of the 6-nitrobenzisoxazole-3-carboxylate anion catalyzed by cross-linked poly(4-vinylpyridinium) salts

Summary Catalysis of cationic polyelectrolytes for the decarboxylation of 6-nitrobenzisoxazole-3-carboxylate anion was studied in a buffer solution (pH=9.0). Cross-linked poly (4-vinylpyridinium) salts prepared from 4-vinylpyridine and , -dibromides were used as cationic catalysts. The cross-linked catalysts were found to accelerate markedly the decarboxylation in comparison with the linear water-soluble analogues. Effect of the polymer structure such as the length of (CH₂)_x linkages between positive charges on the catalytic activity was examined. It was suggested that the acceleration by the cross-linked polymer catalysts would be due to the hydrophobic microenvironment around the catalytic sites.     

Dynamic in situ observation of automotive catalysts for emission control using X-ray absorption fine structure

Two main pivotal subjects of research in automotive catalysts were studied by modern X-ray absorption analysis techniques. One is oxygen storage/release behaviour, and the other is sintering inhibition of Pt particles. First, three types of CeO₂–ZrO₂ (Ce:Zr = 1:1 molar ratio) compounds with different oxygen storage/release capacities and different structural properties were prepared, and the valence change of Ce as a function of temperature during oxygen release/storage processes was investigated. The reduction of surface Ce mainly occurred in the range 100–170 °C, and the reduction of bulk Ce progressed at high temperatures of 170 °C and above. The Ce reduction behaviour depended not only on the homogeneity of the Ce and Zr for bulk reduction at high temperatures but also on the particle size of the CeO₂–ZrO₂ samples for surface reduction at low temperatures. Secondly, sintering inhibition of Pt in Pt/Al₂O₃, Pt/MgO and Pt/ceria-based catalysts after 800 °C ageing in air was studied. We found that the Pt–O–M (M = Mg, Ce) bond acted as an anchor and inhibited the sintering of Pt particles on MgO or ceria-based oxide. Especially, it was noteworthy that the Pt–O–Ce⁴⁺ bond on the ceria-based support breaks easily through the reduction of Ce (Ce⁴⁺ → Ce³⁺) during the usual stoichiometric and reducing conditions.     

Production of hydrogen peroxide by a small molecular mass compound in milk from Holstein cows with high and low milk somatic cell count

Mastitis is the most frequent and prevalent production disease in dairy herds in developed countries. Based on a milk somatic cell count (SCC) of either >300,000 or <200,000 cells/ml in this study, we defined the quarter as either inflamed or uninflamed, respectively. The electrical conductivity (EC) of milk was used as an indicator of udder epithelial cell damage. We determined the amount of H2O2 produced by utilizing a small molecular weight compound in milk, and examined the characteristics of H2O2 production and EC in milk from inflamed and uninflamed quarters. In cows with milk of delivery grade (control population), H2O2 production and EC were 3.6+/-1.3 nmol/ml and 5.4+/-0.4 mS/cm (mean+/-sd), respectively. In 37 inflamed quarter milk samples, the production of H2O2 was 1.9+/-1.0 nmol/ml and was significantly smaller than that in the control population (P<0.01). Production of H2O2 was moderately but significantly correlated with EC (r<-0.71). In 20 cows with inflamed quarters, the production of H2O2 in milk from inflamed quarters was significantly smaller than that in milk from uninflamed quarters (P<0.01). In 18 out of 20 cows, milk from inflamed quarters showed the smallest H2O2 production among all tested quarters in each cow. We conclude that inflammation caused a decrease in H2O2 production in milk. In this study, we present parameters for evaluating the lactoperoxidase/H2O2/thiocyanate antibacterial defence system in bovine milk.     

Pregnancy by Assisted Reproductive Technology Is Associated with Shorter Telomere Length in Neonates

Telomere length (TL) influences the development of lifestyle-related diseases, and neonatal TL may influence their prevalence. Various factors have been reported to affect neonatal TL. Although the fetus is exposed to multiple conditions in utero, the main factors affecting the shortening of neonatal TL are still not known. In this study, we sought to identify factors that influence fetal TL. A total of 578 mother-newborn pairs were included for TL analysis. TL was measured in genomic DNA extracted from cord blood samples using quantitative PCR. The clinical factors examined at enrollment included the following intrauterine environmental factors: maternal age, assisted reproductive technology (ART) used, body mass index (BMI), gestational diabetes mellitus (GDM), maternal stress, smoking, alcohol consumption, preterm delivery, small-for-gestational-age, neonatal sex, and placental weight. Univariate and multivariate regression analyses were used to verify the relationship between neonatal TL and these clinical factors. The median neonatal TL to single-copy gene ratio was 1.0. Pregnancy with ART was among the 11 factors associated with shorter neonatal TL. From multiple regression analysis, we determined that neonatal TL was significantly shorter for pregnancies in the ART group than in the other groups. We conclude that pregnancy with ART is associated with shorter neonatal TL.     

Effect of lubricant fluid on plastic metal flow in sliding contact

Plastic metal flow in surface layers, especially “abnormal metal flow”, in which the direction of metal flow in the inner surface layer is different from that in the layer nearer the surface, in sliding contacts between a pin of cemented carbide and a ring of steel under lubrication is discussed in this paper. Low viscosity mineral oil is used as a base oil. Sulphide and chloride extreme pressure additives are also mixed with the base oil. Such a lubricant has a great influence on the plastic metal flow of a ring.While base oil produces severe plastic metal flow, the sulphide additive causes the plastic metal flow to be very mild. In contrast, a lubricant containing a chloride additive causes abnormal metal flow, where cracks can be seen. Conditions for and causes of abnormal metal flow are investigated.     

Knowledge discovery in databases for determining formulation in topology optimization

Whereas topology optimization has achieved immense success, it involves an intrinsic difficulty. That is, optimized structures obtained by topology optimization strongly depend on the settings of the objective and constraint functions, i.e., the formulation. Nevertheless, the appropriate formulation is not usually obvious when considering structural design problems. Although trial-and-error to determine appropriate formulations are implicitly performed in several studies on topology optimization, it is important to explicitly support the process of trial-and-error. Therefore, in this study, we propose a new framework for topology optimization to determine appropriate formulations. The basic idea of this framework is incorporating knowledge discovery in databases (KDD) and topology optimization. Thus, we construct a database by collecting various and numerous material distributions that are obtained by solving various structural design problems with topology optimization, and find useful knowledge with respect to appropriate formulations from the database on the basis of KDD. An issue must be resolved when realizing the above idea, namely the material distribution in the design domain of a data record must be converted to conform to the design domain of the target design problem wherein an appropriate formulation should be determined. For this purpose, we also propose a material distribution-converting method termed as design domain mapping (DDM). Several numerical examples are used to demonstrate that the proposed framework including DDM successfully and explicitly supports the process of trial-and-error to determine the appropriate formulation.

     

Comparison of the relative stability of pharmaceutical cocrystals consisting of paracetamol and dicarboxylic acids

Objective: The aim of this study is to evaluate the relative stability of pharmaceutical cocrystals consisting of paracetamol (APAP) and oxalic acid (OXA) or maleic acid (MLA).

Significance: These observations of cocrystal stability under various conditions are useful coformer criteria when cocrystals are selected as the active pharmaceutical ingredient in drug development.

Method: The relative stability was determined from the preferentially formed cocrystals under various conditions.

Result: Cocrystal of APAP–OXA was more stable than that of APAP–MLA in a ternary cogrinding system and possessed thermodynamical stability. On the other hand, when grinding with moisture or maintaining at high temperatures and relative humidity conditions, APAP–MLA was more stable, and OXA converted to OXA dihydrate. In the slurry method, APAP–OXA was more stable in aprotic solvents because the APAP–OXA with low-solubility product precipitated.

Conclusions: The relative stability order was affected by preparing conditions of presence of moisture. This order might attribute to the small difference of crystal structure in the extension of the hydrogen bond network.