Improvement of the Vibration Prediction of a Poppet Valve in a Cavitation State

Poppet valves are popular components of hydraulic systems, but they sometimes induce vibration in these systems. In particular, the vibration phenomenon of a poppet valve in a cavitation state is a troublesome problem in hydraulic systems, because the dynamic effects of cavitation on the poppet valve are difficult to predict. In this research, we investigated the vibration phenomenon of the poppet valve in the cavitation state in a visualization experiment and numerical simulation. We found in numerical simulation that it is possible to predict the tendency of the vibration by assuming that the bulk modulus of hydraulic oil is affected by the ratio of cavitation bubbles mixed in the oil. Additionally, we proposed a simple method of estimating the quantity of cavitation bubbles through visualization experiments and image processing. We then improved the prediction accuracy of the poppet valve behavior by applying the bubble mixing ratio obtained using the method in the numerical simulation model. The described methods not only avoid the sensor effect on the flow field but also save the additional measurement cost, and they are easy to apply to hydraulics systems

Influence of Environmental Temperature on Growth of Japanese Quails

Up to date, any precise reports on crystalline lutein, which was comprised at about 20% in carotenoids of green leaves and at about 40% in these xanthophylls, have not been found. In previous report, the authors showed that the glycocarotenoids containing galactose were existent in spinach leaves, and in the processes of these carotenoids purification lutein was found to be crystallized easily from cold acetone in considerably good yields. This crystalline lutein had mp. 174-176℃, and E1cm 1% of 2344 at 446 nm. Furthermore, visible absorption spectrum, IR-spectrum, NMR-spectrum and Mass spectrum were also estimated for the identification of it

Influence of Environmental Temperature on Various Organ Weights on Japanese Quail Chicks

本研究は日本ウズラの成長に及ぼす高温ならびに常温環境の影響を調べる目的で,異なる2つの温度環境（34±2℃,22±2℃）下で飼育された日本ウズラを用いて,2,3,4,5,6週令の体重と各種の器官重について比較検討した. 測定した器官は肝臓,膵臓,心臓,肺臓,腎臓,筋胃,筋胃以外の消化器,精巣,卵巣,卵管および脾臓であった. 得られた結果は以下の通りである. 1)高温区の生体重,屠殺後体重,実質体重および屠体重は常温区のものより劣っていた. 2)高温区のすべての器官重は常温区のものより劣っていた. 高温区と常温区での肝臓,膵臓,筋胃,筋胃以外の消化器には3週令から,心臓,肺臓および腎臓には4週令から,精巣には5週令から有意な差が認められた. しかし脾臓には6週令の雄以外は有意な差が認められなかった. 3)屠体重ならびに器官重と体重との問には有意な正の相関が認められた,屠体重と体重との相関はもっとも高く,つづいて肺臓,心臓,腎臓,筋胃,肝臓,脾臓,膵臓,生殖器の順序であった. 4)器官の比体重値は温度環境の影響を受け,その影響は器宮の種類によって異なることが認められた

Studies on the salt injury on the crops (VII) : Relation between the metallic elements metabolism of wheat and the salt injury.

小麦の塩害と金属代謝との関係について実験を行い次の結果を得た.尚分析は発光分光分析に従い,その地上部のFe,B,Si,P,Mn,Mg,Ca,Cu,Na,K等の含量を求め,特にNaに於ては葉位別,茎の節位別及び穂の各部に於ける含量を測定し,その分布を観察した. 1)NaClの添加と共に,地上部Na量は著しく増大し,Kは僅かに増大し,他の元素はすべて減少の傾向が見られた. 2)作物体内のNa含量の分布は茎に最も多く,葉は之に次ぎ,穂は最も少かつた.然して茎の節位別の分布には差が認められなかつたが,葉では中位葉が上位葉,下位葉に比し僅かに少かつた. 3)本実験結果から推察すると,所謂塩害なる事実は全塩類の高濃度に於ける複合的作用と,之に起因する二次,三次的の影響が綜括せられたものであろう

QUANTITATIVE MEASUREMENT OF TEMPERATURE GRADIENT IN NATURAL HEAT CONVECTION USING COLOR-STRIPE BACKGROUND ORIENTED SCHLIEREN (CSBOS) TECHNIQUE AND COMPUTED TOMOGRAPHY (CT) METHOD

ABSTRACT Quantitative image analysis and measurement of flow fields in convective heat transfer has great importance for the optimum energy consumption problems. In natural and forced convection phenomena of fluids, the complexity of flow field prevents us from detailed three dimensional (3D) experimental analyses of steady/unsteady dynamics in fluids. These flow fields have locally different density and temperature values and yet to be observed quantitatively. Recent development of the Particle Image Velocimetry (PIV) and Particle Tracking Velocimetry (PTV) techniques lead us to the quantitative investigation of flow fields in experimental researches. On the other hand, in image measurements density and temperature distributions have been grasped only in two-dimensions (2D). These qualitative image analyses of flow fields were obtained by using classical flow visualizing techniques, such as shadowgraph and color schlieren method. This paper describes the quantitative measurement of convective flow field using our originally proposed color striped background oriented schlieren (CSBOS) method. The obtained measured image data is used for CT reconstruction and 3D temperature gradient distributions

Altered allergic cytokine and antibody response in mice treated with Bisphenol A

The Objective of this study was to elucidate if Bisphenol A (BPA) administration modulates T helper (Th) cell component of immune responses in a mouse challenged with ovalbumin (OVA), a major food antigen. BALB/c mice, (6 weeks old, female) were orally given either OVA (OVA-fed) or water (Water-fed), immunized intraperitoneally with OVA and injected with either BPA in corn oil or the vehicle alone. After subsequent 2nd immunization, serum titers of total IgE, OVA-specific IgE, IgG, IgG1 IgG2a and ability of their splenocytes for production of interferon (IFN)-γ, interleukin(IL) -4andIL-12 were examined by ELISA. Lymphocyte proliferation assay against concanavalin A (ConA) or OVA was also performed for 3H-Thymidine incorporation. In Water-fed groups, treatment with BPA resulted in lower titers of total IgE(P<0.01) and higher levels IgG2a (P<0.05) followed by a higher IFN-γ (P<0.05) and IL-12 (P<0.05) with an intact IL-4. When OVA-fed groups were examined, the compound did not change production of total and OVA-specific IgE and -IgG2a but resulted in lower production of IFN-γ (P<0.05). Also, BPA resulted in impaired lymphocyte proliferation to Con A in Water-fed groups (P<0.05) but not in tolerated animals. The findings indicate that BPA results in augmentation of Th1 immune responses but no significant effect on an established tolerance to OVA

Expansion Velocity of Ejecta in Tycho's Supernova Remnant Measured by Doppler Broadened X-ray Line Emission

We show that the expansion of ejecta in Tycho's supernova remnant (SNR) is consistent with a spherically symmetric shell, based on Suzaku measurements of the Doppler broadened X-ray emission lines. All the strong K_alpha line emission show broader widths at the center than at the rim, while the centroid energies are constant across the remnant (except for Ca). This is the pattern expected for Doppler broadening due to expansion of the SNR ejecta in a spherical shell. To determine the expansion velocities of the ejecta, we applied a model for each emission line feature having two Gaussian components separately representing red- and blue-shifted gas, and inferred the Doppler velocity difference between these two components directly from the fitted centroid energy difference. Taking into account the effect of projecting a three-dimensional shell to the plane of the detector, we derived average spherical expansion velocities independently for the K_alpha emission of Si, S, Ar, and Fe, and K_beta of Si. We found that the expansion velocities of Si, S, and Ar ejecta of 4700+/-100 km/s are distinctly higher than that obtained from Fe K_alpha emission, 4000+/-300 km/s, which is consistent with segregation of the Fe in the inner ejecta. Combining the observed ejecta velocities with the ejecta proper-motion measurements by Chandra, we derived a distance to the Tycho's SNR of 4+/-1 kpc.Comment: Accepted to Apj, 25 pages, 7 figures, 5 table

Suzaku observation of the metallicity distribution in the intracluster medium of the Fornax cluster

The metallicity distribution in the Fornax cluster was studied with the XIS instrument onboard the Suzaku satellite. K-shell lines of O and Mg were resolved clearly, and the abundances of O, Mg, Si, S and Fe were measured with good accuracy. The region within a 4' radius of NGC 1399 shows approximately solar abundances of Fe, Si and S, while the O/Fe and Mg/Fe abundance ratios are about 0.4--0.5 and 0.7 in solar units. In the outer region spanning radii between 6' and 23', the Fe and Si abundances drop to 0.4--0.5 solar and show no significant gradient within this region. The abundance ratios, O/Fe and Mg/Fe, are consistent with those in the central region. We also measured the Fe abundance around NGC 1404 to be approximately solar, and the O, Ne and Mg abundances to be 0.5--0.7 times the Fe level. The significant relative enhancement of Fe within 130 kpc of NGC 1399 and in NGC 1404 indicates an origin in SN Ia, in contrast to the species O, Ne, and Mg which reflect the stellar metallicity. The mass-to-light ratios for O and Fe within 130 kpc of NGC 1399 are over an order of magnitude lower than those in rich clusters, reflecting the metal enrichment history of this poor cluster.Comment: 13 pages, accepted to PAS

Suzaku Observations of the Centaurus Cluster: Absence of Bulk Motions in the Intracluster Medium

The Centaurus cluster (z=0.0104) was observed with the X-ray Imaging Spectrometer (XIS) onboard the Suzaku X-ray satellite in three pointings, one centered on the cluster core and the other two offset by +-8' in declination. To search for possible bulk motions of the intracluster medium, the central energy of He-like Fe-K line (at a rest-frame energy of 6.7 keV) was examined to look for a positional dependence. Over spatial scales of 50 kpc to 140 kpc around the cluster core, the central line energy was found to be constant within the calibration error of 15 eV. The 90% upper limit on the line-of-sight velocity difference is |Delta_v|< 1400 km/s, giving a tighter constraint than previous measurements. The significant velocity gradients inferred from a previous Chandra study were not detected between two pairs of rectangular regions near the cluster core. These results suggest that the bulk velocity does not largely exceed the thermal velocity of the gas in the central region of the Centaurus cluster. The mean redshift of the intracluster medium was determined to be 0.0097, in agreement with the optical redshift of the cluster within the calibration uncertainty. Implications of the present results for the estimation of the cluster mass are briefly discussed.Comment: 9 pages, 4 figures. Accepted for publication in PASJ. Version with high-quality color figures at http://cosmic.riken.jp/ota/publications/index.htm