Chemical modification of wood by non-formaldehyde cross-linking reagents     

Miss Rie Yasuda  Dr. Kazuya Minato 《Wood Science and Technology》1994,28(2):101-110

Summary Using sulfur dioxide (SO₂) as catalyst, wood specimens were treated with nonformaldehyde cross-linking reagents such as glyoxal, glutaraldehyde and dimethylol dihydroxy ethyleneurea (DMDHEU). The results of dimensional stability, acoustic properties, and mechanical strength tests were compared with those obtained from formaldehyde treatment. With glyoxal and glutaraldehyde treatments, antiswelling efficiency (ASE) reached around 70%, which is comparable to the values attained by formaldehyde treatment, although the accompanying weight gain was much larger than for the latter, whereas DMDHEU did not give sufficiently high ASE. None of the treatments, significantly increased specific dynamic Young's modulus (E/) with the exception of the DMDHEU treatment, loss tangent (tan ) decreased substantially, about 50 and 60% in longitudinal and radial directions respectively, which were somewhat exceeding the formaldehyde treatment. The results suggested that the improvement of the dimensional stability and acoustic properties is partly attributed to the formation of cross-links.  相似文献   

Blackening of Diospyros genus xylem in connection with boron content     

Kazuya Minato  Tamaki Morita 《Journal of Wood Science》2005,51(6):659-662

The amount of boron contained in the xylem of Japanese persimmon (Diospyros kaki Thunb.) and ebony (Diospyros ebenum Koen) was determined by inductively coupled plasma (ICP) emission spectrometry and a modified curcumin–acetic acid method. The boron content was compared between the heartwood and sapwood of ebony as well as between a blackened portion (“kurogaki”) and normal portion of Japanese persimmon. The kurogaki contained a higher level of boron than the normal portion of the same individual, although the boron content varied among individuals. Moreover, the boron content of the heartwood of ebony was much higher than that of the sapwood. These results suggest the participation of boron in the blackening of Japanese persimmon. Because both kurogaki and heartwood of ebony are durable to fungal attack, the blackening of Diospyros genus appears to be related to the formation of defensive substances in which boron seems to take part. The convenient curcumin–acetic acid method is an alternative to the ICP method with comparable accuracy.  相似文献   

Mechanical properties of wood in an unstable state due to temperature changes,and analysis of the relevant mechanism IV: effect of chemical components on destabilization of wood     

Yue Wang  Ikuho Iida  Kazuya Minato 《Journal of Wood Science》2007,53(5):381-387

In order to investigate the effects of chemical components and matrix structure on the destabilization of quenched wood, we examined the physical and mechanical properties of steam-treated wood, hemicellulose-extracted wood, and delignified wood, which were treated at different levels. For steam-treated and hemicellulose-extracted wood,the relative relaxation modulus of the quenched sample was lower than that of the respective control sample. For delignified wood, the relative relaxation modulus fell with weight loss and reached a minimum value at a certain weight loss, and subsequently increased significantly. The hygroscopicity of all treated samples changed slightly by steaming, whereas increased with removing the component. More-over, the average volumetric swelling per 1% MC at 100% relative humidity (RH) was less than at 75% RH and 93% RH for component-removed wood. It was clear that a void structure existed. As a result, the destabilization evaluated by the fluidity (1 - E _t/E ₀) of steam-treated wood was influenced by the amount of adsorbed water. For component-removed wood, destabilization increased temporarily at lower weight loss because of nonuniform cohesive structure. At high weight loss, destabilization will decreased because capillary-condensed water gathered in the voids and obstructed the motion of adsorbed water. However, the destabilization of all treated wood changed less than that of chemically modified wood.  相似文献   

Histopathologic observations on galactose-induced cataract in rats     

I Wada  T Fukushima  Y Minato  K Imaizumi  M Takeshita  A Okaniwa 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1988,50(3):659-664

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Electron microscopy of renal arterial lesion in a pup infected with canine herpes virus.     

T Yamamura  Y Minato  A Kojima  A Okaniwa 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1992,54(4):779-780

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Pleomorphic liposarcoma in an aged rat     

Y Minato  H Takada  H Yamanaka  A Kojima  I Wada  M Takeshita  A Okaniwa 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1986,48(2):429-432

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Erratum to: Identification of anisotropic vibrational properties of Padauk wood with interlocked grain     

Iris Brémaud  Pierre Cabrolier  Joseph Gril  Bruno Clair  Jean Gérard  Kazuya Minato  Bernard Thibaut 《Wood Science and Technology》2010,44(4):705-705

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Outbreak of neonatal canine herpesvirus infection in a specific pathogen-free beagle colony     

A Kojima  F Fujinami  M Takeshita  Y Minato  T Yamamura  K Imaizumi  A Okaniwa 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1990,52(1):145-154

Nine out of 19 newborn pups from 4 litters died or euthanatized on day 10 to 17 after birth in a specific-pathogen-free beagle colony which had been established by cesarean section and bottle-feeding. Necropsy showed congestion and edema of the lungs, congestion of the liver and splenomegaly, as well as many subcapsular petechiae and wedge-shaped areas of ecchymosis on the cut surface of the kidneys. A cytopathic agent isolated from the lungs, kidneys and liver was identified as a canine herpesvirus. The bitches in the animal house were seroconverted into positive for the isolate after the outbreak of the disease. Histopathological lesions in six cases were characterized by multiple necrosis and hemorrhage in various organs. In addition, fibrinoid necrosis was seen in the arterial walls in wedge-shaped necrotic areas of the kidneys. The outbreak appeared to be temporary, since the same disease has not occurred in the colony up to the present time.  相似文献   

The cumulative methane production from dairy cattle slurry can be explained by its volatile solid,temperature and length of storage          下载免费PDF全文

Takuji Sawamoto  Megumi Nakamura  Kenji Nekomoto  Shinji Hoshiba  Keiko Minato  Motoo Nakayama  Takashi Osada 《Animal Science Journal》2016,87(6):827-834

In order to refine the national estimate of methane emission from stored cattle slurry, it is important to comprehend the basic characteristics of methane production. Two dairy cattle slurries were obtained from livestock farms located in Hokkaido (a northern island) and Kyushu (a southern island). The slurries were diluted with water into three levels: undiluted, three times diluted, and 10 times diluted. Three hundred mL of the slurries were put into a bottle with a headspace volume of 2.0 L, which was filled with nitrogen gas and then sealed by butyl rubber. Four levels of temperature were used for incubation: 35, 25, 15 and 5 °C. The time course of the cumulative methane production per volatile solid (VS) was satisfactorily expressed by an asymptotic regression model. The effect of dilution on the methane production per VS was not distinctive, but that of temperature was of primary importance. In particular, higher temperature yields a higher potential production and a shorter time when the cumulative production reaches half of the potential production. The inclusive and simple models obtained in this study indicate that the cumulative methane production from stored cattle slurry can be explained by VS, temperature and length of storage.  相似文献   

Influence of moisture content on the vibrational properties of hematoxylin-impregnated wood     

Eiichi Obataya  Kazuya Minato  Bunichiro Tomita 《Journal of Wood Science》2001,47(4):317-321

The vibrational property of hematoxylinimpregnated wood was investigated from the aspect of moisture content dependence. The specific dynamic Young's modulus (E/) and loss tangent (tan) of hematoxylin-impregnated wood were determined in the relative humidity (RH) range of 0%–97%, and were compared with those of the untreated and some conventional chemically treated woods. The changes in theE/ and tan of wood with increasing RH were suppressed by acetylation and formaldehyde treatment because of a marked reduction in the hygroscopicity of the wood. Although the hematoxylin impregnation did not significantly affect the hygroscopicity of the wood, its influence onE/ and tan were similar to that of formaldehyde treatment at low RH and of acetylation at medium RH. It was supposed that at low to medium RH hematoxylin restrains the molecular motion of amorphous substances in the cell wall because of its bulkiness and rigidity. On the other hand, at high RH it seems to work as a plasticizer with adsorbed water molecules.  相似文献