Japanese Wood Research Articles

Thermogravimetric analysis with gas chromatograph mass spectrometry of Japanese fir wood (Abies sachalinensis) in helium with or without steam–oxygen

Thermal properties of a kind of Japanese fir wood (Abies sachalinensis) were thermogravimetrically analyzed and produced compounds were gas chromatograph mass spectrometrically analyzed for basic study of biomass gasification. Atmosphere during each analysis was controlled to be helium alone or helium with steam–oxygen. Compounds identified in this series of measurements were roughly classified into three groups: (a) phenol and its derivatives, (b) oxygenated cyclic compounds, and (c) oxygenated compounds of low molecule. Their production rates were dependent on both temperature and atmosphere, which well explained high carbon conversion rate from feedstock to gas of advanced gasification technologies, such as entrained-flow type gasification, and high yields of solid and liquid residues of traditional gasification technologies, such as fixed-bed type gasification.

Historical Effects on Local Variation in Walnut-Feeding Behavior by the Japanese Wood Mouse, Apodemus speciosus

The Japanese wood mouse Apodemus speciosus eats large, hard-walled walnuts of Juglans ailanthifolia immediately after finding or after hoarding them. However, not all individuals can efficiently eat the nuts. In this study, to examine local variation in the ability to eat walnuts, feeding behavior was compared among nine wood mouse populations, four from mainland Honshu, where the walnut tree is distributed, and five from the Izu Islands (30-100 km south of Honshu), which lack the tree species. To avoid the effects of pre-capture experience with walnuts, mice from areas lacking the walnut trees were used for testing, even in the Honshu sites. Most mice from Honshu were able to eat walnuts after a 14-day training period, whereas most insular mice could not, with the exception of mice on Kouzushima Island. An analysis of the population genetic structures of these mice based on sequences of the mitochondrial control (D-loop) region revealed that the four insular populations are genetically distinct from the mainland populations, whereas the Kouzushima population remains genetically similar to the mainland populations. The relatively recent colonization of Kouzushima may explain why mice from this island were able to feed on walnuts despite the lack of walnut trees on the island. Thus, walnut-feeding ability appears to have some innate basis in the Japanese wood mouse, and this trait would be selected for in a walnut-available environment as it would better enable mice to survive during food shortages.

Wind Effect on Vibration and Scattering Behavior of Japanese Roofing Tile

A series of wind tunnel tests were conducted on the vibration and scattering behavior of full-size models of tiles widely used as roofing materials on Japanese wooden dwellings. This study has investigated the nature and source of such movement with the aim of providing better insight into the mechanism. The result of these measurements indicates that a basic mechanism can be developed that will lead to flow-induced vibration of the roofing tiles. The values of the oscillation frequencies relate to the values of natural frequencies of the vibration.

Interspecific Differences in Tannin Intakes of Forest-Dwelling Rodents in the Wild Revealed by a new Method Using Fecal Proline Content

Mammalian herbivores adopt various countermeasures against dietary tannins, which are among the most widespread plant secondary metabolites. The large Japanese wood mouse Apodemus speciosus produces proline-rich salivary tannin-binding proteins in response to tannins. Proline-rich proteins (PRPs) react with tannins to form stable complexes that are excreted in the feces. Here, we developed a new method for estimating the tannin intake of free-living small rodents, by measuring fecal proline content, and applied the method to a field investigation. A feeding experiment with artificial diets containing various levels of tannic acid revealed that fecal proline content was clearly related to dietary tannin content in three species (A. speciosus, Apodemus argenteus, and Myodes rufocanus). We then used fecal proline content to estimate the tannin intakes of these three forest-dwelling species in a forest in Hokkaido. In the autumn, estimated tannin intakes increased significantly in the Apodemus species, but not in M. rufocanus. We speculated that an increase in tannin intake during autumn may result from consumption of tannin-rich acorns. This hypothesis was consistent with population fluctuation patterns of the three species, which were well-synchronized with acorn abundance for the Apodemus species but not for M. rufocanus.

Genetic Diversity of the Japanese Wood Pigeon,Columba janthina, Endemic to Islands of East Asia, Estimated by Newly Developed Microsatellite Markers

The Japanese wood pigeon Columba janthina is endemic to islands of East Asia and is listed as Near Threatened by the International Union for Conservation of Nature (IUCN). One subspecies, C. janthina nitens, in particular, is at the greatest risk of extinction due to its small population size. To reduce the extinction risk of C. janthina, it is important to understand the species' present genetic status and to develop an appropriate conservation plan based on genetic data. We developed seven new microsatellite markers for two subspecies of C. janthina: C. janthina janthina and C. janthina nitens. We also confirmed the cross-use of one microsatellite marker developed for Columba livia var. domestica. Seven loci were polymorphic in C. janthina janthina, while two loci were polymorphic in C. janthina nitens. Using the markers, we performed preliminary analysis of genetic diversity and genetic structure within each subspecies. The expected heterozygosity ranged from 0.00 to 0.64 in C. janthina janthina and from 0.00 to 0.08 in C. janthina nitens. Each subspecies and each population within C. janthina janthina had different allele frequencies. C. janthina nitens exhibited far lower genetic diversity than C. janthina janthina. Furthermore, C. janthina nitens appears to have experienced strong genetic drift from a common ancestral population, inferred by STRUCTURE analysis. The markers described here may be useful for investigating genetic diversity and genetic structure of C. janthina populations, and could be used to estimate appropriate evolutionary significant unit and to guide development of a captive breeding program based on genetic information.

Bending resistance of repaired column members and shear resistance of opening frames with repaired columns of conventional Japanese wooden houses

When it is necessary to repair conventional Japanese wooden houses, the decayed lower parts of columns should be replaced with new wood material. The bending resistance of columns repaired by four methods and the shear resistance of opening frames with those repaired columns were investigated in this study. Bending tests of the repaired columns showed differences in initial bending stiffness and maximum bending moment related to the repair methods and loading direction. Racking tests were conducted on door opening frames with conventional door head members or upper partial walls sheathed with 12-mmthick plywood. The conventional frame specimens broke at door head-column joints with no obvious bending deformation of the columns, resulting in little difference in load-shear deformation curves among the repair methods. The columns of plywood-sheathed specimens, on the other hand, clearly were bent after the nails at the plywood-to-wood frame joints started to pull off. The load-shear deformation curves of the plywood-sheathed specimens did not vary regardless of the repair methods when shear deformations were small but were affected by repair methods as shear deformation increased.

실험조건에 따른 임팩트 볼의 바닥충격음 변화 고찰

본 연구의 목적은 일본의 표준 중량충격원인 임팩트 볼을 국내의 표준중량충격원으로 도입시 바닥충격음 실험에 있어서 정확성에 대해 실험을 통해 알아보고자 했다. 이를 위하여 임팩트 볼을 이용하여 낙하 높이별, 가진위치를 바꾸어서, 수음점 높이에 대한 논의를 진행하였고, 임팩트 볼을 이용한 바닥충격음을 측정하고 이를 실제 충격원인 뛰는 충격음과 비교하여 실제 충격음과 가장 유사한 낙하 높이에 대한 검토를 실시하였다. 또한 일본 주택에서 주로 사용되고 있는 목구조와 국내 공동주택의 기본 구조인 콘크리트 구조에서의 바닥충격음 특성차이를 알아보기 위해 실험동에서 같은 조건으로 시험을 실시하여 시공재료 및 구법에 따른 차이를 알아보고자 하였다. 이에 대한 결과는 목구조에서는 낙하 높이가 10 cm에서 30 cm사이의 충격음이 실제 충격음과 비슷한 음압레벨을 갖는 것으로 나타났고 콘크리트 구조에서는 유사한 음압의 높이는 없었다. 또한 사람이 임팩트 볼을 운용하면서 표준낙하높이를 기준으로 상 하 10 cm 높이차로 생기는 오차는 역 A특성 값에서 약 1 dB이하 정도로 작은 오차를 나타내긴 하지만 우리나라에 표준 중량충격원으로 도입할 때에는 다양한 콘크리트 바닥구법에 따른 바닥충격음의 특성에 따른 적합한 임팩트 볼의 낙하 높이 및 측정 마이크로폰의 높이에 대한 고려는 신중히 하여야 한다. In Japan, bang machine has been considered to have problems about not only the impact force and frequency response which are different from the real impact sources such as children's jumping and running, but also damage in the wooden structure housing. Therefore, a new impactor for lower impact force to prevent demage in wooden structure housing was developed. The impact ball was adopted as the second standard impact source in JIS A 1418-2 and ISO 140-11. In the present study, floor impact sounds generated by impact ball with drop heights in four floors of mock-up building of Building Research Institute (BRI) similar to typical Japanese wooden structure housing were investigated and also compared to jumping sound. The results show that Impact ball sound dropped at 10 cm to 30 cm was most similar to jumping sound. And The impact sound levels at 250 and 500 Hz were more sensitive to drop height than other lower frequencies. The error that may occur from the difference of height of 10 cm up and down based on the standard drop height caused by the impact ball operated by human hands was approx. 1 dB or less only in its value of characteristic, but it must be carefully taken into Impact ball in the Korea Standard.

INUNDATION FLOW VELOCITY OF TSUNAMI ON LAND AND ITS PRACTICAL USE

Based on field data of inundation depth and inundation flow velocity u estimated using Bernoulli's theorem and inundation depth, fundamental characteristics of relationship between inundation flow velocity and inundation depth are examined. Velocity coefficient Cv (= where g is gravitational acceleration, hf and hr are inundation depths at the front and the back of structure such as a rectangular building with vertical walls respectively) implicitly included in the relationship is examined through steady flow experiments. As the result, Cv0.6 is recommended as its simple and practical value. By using the relationship and Cv0.6, two simple and practical relationships are presented for two cases where inundation flow velocity exerts the largest or the smallest fluid force on structures. Fundamental characteristics of waterline (tsunami-trace) distribution around a square pillar model are also examined through steady flow experiments. Examples of tsunami-trace distribution around building in the 2009 Samoa Earthquake tsunami are presented, and compared with those by steady flow experiments. It is confirmed through the comparison and examination that the tsunami-trace distributions around buildings by the field survey are consistent with those by the steady flow experiments and contain information such as inundation flow direction, velocity and fluid force at the maximum incident inundation depth, and strength of buildings. Variation coefficient C.V. of inundation flow velocity caused by the measured point difference at the front and the back of building is also examined. In addition, based on the above results of inundation flow velocity, the existing simple and practical judgment criterion for the degree of damage to buildings is re-examined, and it is confirmed that newly proposed judgment criterion for the degree of damage to wooden buildings is consistent with the tsunami fragility curve for Japanese wooden buildings by Koshimura et al.

カラスバト<i>Columba janthina</i> の新潟市への迷行記録

An individual of the Japanese Wood Pigeon Columba janthina, which inhabits islands in the ocean, accidentally visited Niigata, Central Honshu, Japan, and was observed on 13 November, 2010.

The Avifauna in Ulleungdo

The avian fauna of Ulleungdo (Is.) was studied between June of 2006 and July of 2010, and the results gathered over 10 study session included a total of 18,046 individuals of 92 species. Dominant species included, in decreasing order, black-tailed gull (Larus crassirostris) at 13,188 individuals (73.1%), russet sparrow (Passer rutilans) at 1,278 individuals (7.08%), and white-rumped swift (Apus pacificus) at 900 individuals (4.99%). In terms of the time of the year, the highest numbers of species were detected in May of 2007 at 50 species and the highest numbers of birds were detected in February of 2009 at 4,137 individuals. In relation to endangered species designated by the Ministry of Environment, the peregrine falcon (Falco peregrinus) and Eurasian buzzard (Buteo buteo) were detected, and natural monument species designated by the Cultural Heritage Administration including the Japanese wood pigeon (Columba janthina), grey frog hawk (Accipiter soloensis), common kestrel (Falco tinnunculus), peregrine falcon, oriental scops owl (Otus scops), mandarin duck (Aix galericulata) and the little cuckoo(Cuculus poliocephalus) were detected. Compared to previous studies, a total of 33 new species, including the red-throated diver (Gavia stellata) and the Swinhoe's fork-tailed petrel (Oceanodroma monorhis), were observed.

Structural Changes in Japanese Wood Imports and Trading Companies' Adaptations

Structural Changes in Japanese Wood Imports and Trading Companies' Adaptations

The Evolution of Ancient East Asian Writing Systems as Observed through Early Korean and Japanese Wooden Tablets

The Evolution of Ancient East Asian Writing Systems as Observed through Early Korean and Japanese Wooden Tablets

Evaluation of Shear Strength of Japanese Wood Species as a Function of Surface Roughness

The objective of this study was to evaluate shear strength characteristics of four commonly used Japanese species, namely, Japanese cedar-sugi (Cryptomeria japonica D. Don), Japanese cypress-hinoki (Chamaecyparis obusta Endl.), false arborvitae-hiba (Thuobsis dolabrate Sieb. et Zucc.), and Japanese larch-karamatsu (Larix leptlepis Gordon), as function of their surface quality. Samples with radial and tangential grain orientations from each species were prepared using a planer and sanded with one of the sandpapers with 80-, 120-, and 240-grit size. A stylus type of equipment was employed to determine surface roughness of each sample before they were bonded in radial and tangential pairs using polyvinyl acetate (PVAc) adhesive at a spread rate of 260 g/m2. None of the samples showed any superiority from each other in terms of their surface quality based on three parameters: average roughness (Ra), mean peak-to-valley height (Rz), and maximum roughness (Rmax). Average roughness value of both tangential and radial surfaces of the samples sanded with 80-grit sandpaper resulted in significant differences from those of the control samples. The highest shear strength value was 96.1 kg/cm2 for the radial karamatsu samples sanded with 80-grit sandpaper followed by tangential hinoki samples with the value of 79.6 kg/cm2. In general, the samples finished with 80-grit sandpaper resulted in higher shear strength values than the others tested in this work. It appears that stylus-type equipment can be used to evaluate surface quality of such solid wood samples. Based on the results of this study, sanding of the samples with 80-grit sandpaper improved overall shear strength of the specimens by developing a better glue line between two pieces.

Mitochondrial Phylogeography and Population History of the Large Japanese Wood Mouse (Apodemus speciosus) on Sado Island, Japan

Abstract. A phylogeographic study of the large Japanese wood mouse, Apodemus speciosus, on Sado Island, Japan, was performed based on sequences of the mitochondrial cytochrome b gene (1,140 bp). Our previous study covered the entire species range and suggested that the mice on Sado Island are monophyletic, exhibiting two well diverged lineages throughout the island. The present data also supported two lineages (the average number of nucleotide difference was 11.4), showing a weak phylogeographic structure. Given the high sequence divergence observed, we assumed historically subdivided populations within the island. Bayesian coalescent analysis supported a dual-population model rather than that of one large population. The times to most recent common ancestor of all sequences were 293,000 years ago [ka; 95% highest probability density (HPD) 85–634 ka] and 292 ka (HPD 102–605 ka) for the one- and dual-population models, respectively. These results suggest that the populations have undergone repeated separat...

Enzymatic Saccharification of Japanese Cedar Wood by Combined Pretreatments using White Rot Fungus and Organosolvolysis with Lactic Acid

難分解性の針葉樹にも対応できる低環境負荷酵素糖化前処理法の開発を目指し，スギ材に対して，リグニンを高選択的に分解する白色腐朽菌処理と，乳酸，酢酸などの有機酸とエタノール，グリセロール，プロピレングリコールなどの溶媒系の組み合わせからなるマイクロ波ソルボリシス複合処理を試みた。白色腐朽菌Phellinus sp. SKM2102は，エタノリシス後酵素糖化によって得られる還元糖の収率を最大で5倍以上増加させた。バイオマスからの生産が可能な安全性が高い有機酸，アルコールの組み合わせでは，エタノールと乳酸を組み合わせたソルボリシスが最も高い酵素糖化前処理効果を示した。

Performance Analysis of MIMO Schemes in Residential Home Environment via Wideband MIMO Propagation Measurement

This paper illustrates a large-scale MIMO propagation channel measurement in a real life environment and evaluates throughput performance of various MIMO schemes in that environment. For that purpose, 4 × 4 MIMO transceivers and a novel spatial scanner are fabricated for wideband MIMO channel measurements in the 5GHz band. A total of more than 50, 000 spatial samples in an area of 150m2, which includes a bedroom, a Japanese room, a hallway, and the living and dining areas, are taken in a real residential home environment. Statistical properties of the propagation channel and throughput performance of various MIMO schemes are evaluated by using measured data. Propagation measurement results show large dynamic channel variations occurring in a real environment in which statistical properties of the channel, such as frequency correlation and spatial correlation are not stationary any more, and become functions of the SNR. Furthermore, evaluation of throughput shows that although MIMO schemes outperform the SISO system in most areas, open loop systems perform badly in the far areas with low SNR. Paying for the cost of CSI or partial CSI at Tx, closed loop and hybrid systems have superior performance compared to other schemes, especially in reasonable SNR areas ranging from 10dB to 30dB. Spatial correlation, which is common in Japanese wooden residences, is also found to be a dominant factor causing throughput degradation of the open loop MIMO schemes.

Tsunami-trace Distribution around Buildings and Its Practical Use - Examples in the 2009 Samoa Earthquake Tsunami -

Examples of tsunami-trace distribution around building in the 2009 Samoa Earthquake tsunami are presented, and compared with those by laboratory experiments. It is confirmed through the comparison that the tsunami-trace distributions around buildings by the field survey are consistent with those by the laboratory experiments and involve information such as an inundation flow direction, velocity and force at the maximum incident inundation depth, and strength of buildings. Variation coefficient of inundation flow velocity caused by a measured point difference at the front and the back of building is also examined. In addition, based on a recent knowledge of inundation flow velocity, the existing judgment criterion for the degree of damage to buildings is re-examined, and a newly proposed judgment criterion is confirmed to be consistent with Koshimura et al.'s tsunami fragility curve for Japanese wooden buildings.

A Trend of Central Versus Peripheral Structuring in Mitochondrial and Nuclear Gene Sequences of the Japanese Wood Mouse, Apodemus speciosus

A phylogeographic analysis was performed on Japanese endemic wood mice (Apodemus speciosus) using nuclear interphotoreceptor retinol binding protein (IRBP) gene sequences (1,152 bp), together with previously published mitochondrial cytochrome b (cyt b) data. In the IRBP analysis, 40 haplotypes were recovered from 84 individuals by statistical and subcloning methods. Substantial sequence variation was determined from the IRBP data (pi=0.0047), and no significant evidence of recombination was detected. From the phylogenetic analysis, the 40 haplotypes fell into two major groups with geographic associations, irrespective of the karyotype groups (2n=46 and 2n=48), yielding a trend of central (Hokkaido, Honshu, Shikoku, Kyushu, and Sado) and peripheral (Izu, Oki, Tsushima, and Satsunan Is.) groupings. This geographic pattern is similar to that observed in the cyt b data, with a different insular grouping of Sado, Hokkaido, Izu, and Satsunan islands, and also to that of morphological features. In both gene data sets, nested clade analyses revealed allopatric fragmentation in the "peripheral island clades" and range expansion in the "central island clades." A mismatch analysis using cyt b data also suggested expansion of the central islands clade. Thus, the trend of central vs. peripheral structuring may be attributable to past demographic dynamics in the two distinct haplotype clades, such as range expansion of one clade in the central area of the Japanese Islands, leaving the other clade in the periphery.

Selective consumption of acorns by the Japanese wood mouse according to tannin content: a behavioral countermeasure against plant secondary metabolites

AbstractWe examined the presence of selective consumption against tannins in acorns as a pre‐ingestive countermeasure to plant secondary metabolites by using the Japanese wood mouse (Apodemus speciosus) and acorns of Quercus serrata, which contained ca. 6.4% tannins on a dry weight basis. In addition, the presence of selective consumption against proteins was also examined. In the acorn‐feeding experiment, 18 wood mice were allocated to two groups: the experienced group (N = 9), which had previous experience in feeding on acorns, and the inexperienced group (N = 9), which had no experience. Mice of both groups were fed only acorns for 3 nights. Selectivity against tannins (an index estimated from the tannin content in control, remaining, and ingested acorns) was significantly positive in the experienced group, indicating the presence of selective consumption against tannins. In contrast, mice in the inexperienced group did not show significant selectivity against tannins. Comparing the selectivity indices directly between two groups, however, they did not differ significantly. Selective consumption against proteins rather than that for proteins also occurred in the experienced group, but it was thought to be a byproduct resulted from the selectivity against tannins. Selective consumption against tannins can mitigate the negative effects of tannins by decreasing tannin intake.

Effects of acorn abundance on density dependence in a Japanese wood mouse (Apodemus speciosus) population

AbstractWe analysed the effects of Quercus crispula acorn abundance on the density dependence of the large Japanese wood mouse Apodemus speciosus using time series data (1992–2007). The data were obtained in a forest in northern Hokkaido, Japan, by live‐trapping rodents and directly counting acorns on the ground. Acorn abundance in one year clearly influenced the abundance of wood mice in the following year in all models examined based on the Gompertz and Ricker model; in addition, the abundance of wood mice had effects on the population. Acorn abundance influenced the strength of density dependence (intraspecific competition) of the wood mouse population. When the abundance of acorns was high, density dependence was relaxed, and as a result the equilibrium density at which the population growth rate decreased to zero became higher. Those effects of acorn abundance were regarded as a nonlinear perturbation effect (sensu Royama 1992). The nonlinearity of density dependence was also detected; higher densities had stronger effects on population growth rates.