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1.
Self-bonding is the main factor of the performance expression of binderless boards, and therefore its clarification is considered
to be an important issue. For this purpose, a series of chemical analyses were conducted on kenaf core binderless boards and
their chemical changes during the hot-pressing process are discussed in this article. First of all, binderless boards were
prepared from kenaf core powder at different pressing temperatures (without steam-explosion process) and were used for chemical
analyses after they were reduced into powders and extracted with methanol. To investigate their chemical changes, lignin,
holocellulose, and neutral sugar contents were determined, Fourier transform infrared (FTIR) spectra were recorded, and the
nitrobenzene oxidation procedure was applied. As a result, it was found that parts of lignin and hemicelullose were decomposed
during the hot-pressing process; however, the contribution of the resulting fractions to selfbonding was not observed. In
addition, progress of condensation reactions in lignin and the formation of chemical bonds by low molecular weight conjugated
carbonyl compounds in methanol extractives were observed. Thermal softening of lignin is also suggested to play an important
role in the expression of board performance. 相似文献
2.
Binderless boards were prepared from finely ground powders of kenaf (Hibiscus cannabinus L.) core under varying manufacturing conditions. This research was designed to investigate their mechanical properties and evaluate the various manufacturing conditions: pressing temperature and time, pressing pressure, board density, board thickness, grain size of raw materials, and addition of furfural. The mechanical properties (i.e., modulus of rupture and elasticity, internal bonding strength) of boards increased with increasing board density and met the requirement for 15 type medium-density fiberboard (MDF) by JIS A 5905-1994. Thickness swelling and water absorption of boards exceeded the maximum permitted levels for 15 type MDF and S20 grade hardboard by JIS A 5905-1994, which indicates the low water-resistant property of binderless boards. In contrast to that in usual wood-based materials, internal bonding strength showed significant correlations with other board properties: modulus of rupture and elasticity, thickness swelling, and water absorption. We confirmed experimentally that the best manufacturing conditions proved to be as follows: pressing temperature 180°C, time 10min; pressing pressure 5.3MPa; board thickness 5mm; board density 1.0g/cm3; average grain size 53µm; and powder with no furfural content.Part of this paper was presented at the 52nd Annual Meeting of the Japan Wood Research Society, Gifu, April 2002 相似文献
3.
Shinya Mizuno Shigehiko Urawa Mahito Miyamoto Makoto Hatakeyama Nobuhisa Koide Hiroshi Ueda 《Journal of fish diseases》2019,42(1):129-140
In northern Japan, juvenile chum salmon Oncorhynchus keta (Walbaum) are released from hatcheries to enhance the fishery resource. Infections with ectoparasitic protozoans, particularly the flagellate Ichthyobodo salmonis and the ciliate Trichodina truttae, occasionally cause severe mortality among hatchery‐reared juveniles. This study examined the susceptibility of the two parasites to wide‐ranging UV irradiation (experiment 1) and then investigated whether UV disinfection of the rearing water using a commercial device was useful for preventing infections among juveniles in a small‐scale rearing system over a 28‐day period (experiment 2). In experiment 1, parasite mortality reached 100% with UV irradiation doses of ≥9.60 × 105 μW s/cm2 for I. salmonis and ≥8.40 × 105 μW s/cm2 for T. truttae. In experiment 2, disinfection of the rearing water at a UV irradiation dose of 2.2 × 106 μW s/cm2 succeeded in complete prevention of both parasites in the juvenile salmon. These results elucidate the minimum dose of UV irradiation for inactivation of I. salmonis and T. truttae, and demonstrate the usefulness of water disinfection using a commercial UV irradiation device to prevent infections by these parasites in hatchery‐reared juvenile chum salmon. 相似文献
4.
Toki Nishiyama Nobuhisa Ashida Koichi Nakagawa Shun Iwatani Naoyuki Yamamoto 《The Journal of Poultry Science》2021,58(2):138
Among the reported probiotic Bacillus strains, B. subtilis C-3102 has the unique potential to improve feed uptake under stress conditions in the broilers, piglets, and cows. In this study, we sought to evaluate the protective effect of feed additive probiotic Bacillus subtilis C-3102 against Salmonella enterica infection of specific pathogen-free (SPF) chicks in floor pens in two experiments. In the experiment-1, the chicks in the control group (n=32) were fed a basal diet and those in the C-3102 group (n=32) were fed a basal diet supplemented with 1×106 CFU/g of feed for 28 days. On day 7 post-challenge with S. enterica, there was no significant change in the body weight between both the groups throughout the test period, whereas detection rates of S. enterica in the C-3102 group were significantly lower in the cecum and liver on days 21 and 14 post-challenge, respectively. In the experiment-2, minimum dosage of C-3102 cells required to protect Salmonella infection was evaluated using 3 dosages. Chicks were divided into four groups, fed with different dosages of C-3102 (1×106, 5×105, 3×105, and 0 CFU/g of feed), and challenged with S. enterica (2.8×108 CFU/chicken). S. enterica infection was completed within 7 days post- challenge and was almost excluded from the liver and spleen on day 21 post- challenge in the control group. Average values showed a trend for higher infection rates in the control group >3×105>5×105>1×106 CFU/g on days 14 and 21 post-challenge. These results suggest that B. subtilis C-3102 supplementation has the potential to reduce S. enterica infection rates and/or to accelerate the exclusion of S. enterica from the chicks. 相似文献
5.
Satoshi Koike Machiho Ueno Nobuhisa Ashida Tomokazu Imabayashi Yasuo Kobayashi 《Animal Science Journal》2021,92(1):e13580
We aimed to assess the effect of feeding Bacillus subtilis C-3102 on the growth and rumen microbiota in the preweaned calves. Twelve newborn Japanese Black calves were randomly allocated to either the control (n = 6) or the treatment (n = 6) groups in the present study. Calves in the treatment group were offered B. subtilis C-3102 supplemented milk replacer throughout the preweaning period. Rumen fermentation during the first 21 days of life seemed to be slightly suppressed by feeding B. subtilis C-3102. This fermentation shift was probably attributed to the lower abundance of the core members of rumen microbiota until 21 days of age in the calves fed B. subtilis C-3102. However, feeding B. subtilis C-3102 did not influence the abundance of the core members of rumen microbiota at 90 days of age. Distribution of Sharpea spp. and Megasphaera spp., which potentially contribute to low methane production and are regarded as beneficial rumen bacteria, was higher in the rumen of calves fed B. subtilis C-3102 at 90 days of age. These results suggest that B. subtilis C-3102 supplementation in milk replacer could potentially contribute to the improvement of feed efficiency after weaning via the establishment of beneficial rumen bacteria. 相似文献
6.
Satoshi?KusudaEmail author Nobuhisa?Koide Hiloshi?Kawamula Tetsuo?Teranishi Jun?-Ichiro?Nakajima Etsuro?Yamaha Katsutoshi?Arai Hiromi?Ohta 《Fisheries Science》2005,71(2):293-298
To develop a suitable cryopreservation diluent for spermatozoa of the endangered Sakhalin taimen Hucho perryi, all possible combinations of cryoprotectants (glycerol, dimethyl sulfoxide [DMSO], methanol) and extenders (fetal bovine
serum [FBS], 300 mM glucose solution [GS], artificial seminal plasma for masu salmon) were examined by observing sperm motility
10 s after thawing. Spermatozoa cryopreserved with diluents such as mixtures of 10% glycerol plus 90% FBS, 10% DMSO plus 90%
FBS, and 10% methanol plus 90% GS showed the highest motility. The maximal post-thaw motility was observed at 10% among all
concentrations (0, 5, 10, 15 and 20%) of these three cryoprotectants. No significant difference among three diluents was observed
in motility at 10 s. Mixtures of 10% glycerol plus 90% FBS, 10% DMSO plus 90% FBS, and 10% methanol plus 90% GS are suitable
cryopreservation diluents for Sakhalin taimen spermatozoa. 相似文献
7.
Nobuhisa Koga 《Soil Science and Plant Nutrition》2013,59(1):56-68
In the context of their role in global warming, nitrous oxide (N2O) emissions from agricultural soil under different management practices were studied in Hokkaido, northern Japan. To assess the impacts of reduced tillage, composted cattle manure-based fertilization and amendments with crop residues and green manure on N2O emissions from soil, a field experiment was conducted under a four-year crop rotation on a well-drained Andisol. The crop rotation included potato (Solanum tuberosum L.) or sweet corn (Zea mays L.), winter wheat (Triticum aestivum L.), sugar beet (Beta vulgaris L. subsp. vulgaris) and soybean (Glycine max (L.) Merr.). The cumulative N2O emissions for the four-year study period differed widely (0.33 to 4.90?kg?N?ha?1), depending on the treatments imposed, being the greatest for a combination of conventional moldboard plow tillage, composted cattle manure-based fertilization and increased plant residue input, and the lowest for a combination of conventional tillage, chemical fertilizer-based fertilization and normal plant residue input treatments. The cumulative N2O emissions under reduced tillage were all small, irrespective of fertilization and plant residue input treatments. Composted cattle manure-based fertilization (P?≤?0.01) and increased plant residue input (P?≤?0.01) significantly increased cumulative N2O emissions. Tillage showed a significant interaction with fertilization and plant residue input, indicating that N2O emissions were enhanced when composted cattle manure, crop residues and green manure were incorporated by conventional tillage. In the present study, the N2O emission factors for chemical fertilizer, composted cattle manure and crop residues were 0.26?±?0.44, 0.11?±?0.16 and ?0.03?±?0.52%, respectively, all much lower than the country-specific emission factor for Japan's well-drained soils (0.62%) and the default emission factor used in the IPCC guideline (1%). 相似文献
8.
Shinya Mizuno Shigehiko Urawa Mahito Miyamoto Makoto Hatakeyama Nobuhisa Koide Hiroshi Ueda 《Fisheries Science》2017,83(2):283-290
Ichthyobodosis caused by the ectoparasitic flagellate Ichthyobodo salmonis is a significant cause of mortality in juvenile chum salmon Oncorhynchus keta reared in hatcheries of northern Japan. The present study established a real-time quantitative polymerase chain reaction assay (qPCR) of I. salmonis ribosomal DNA (rDNA) using SYBR Green. This assay allows monitoring of parasite infections for the epidemiological study and control of ichthyobodosis in hatcheries. qPCR showed high reproducibility for measurements between 1.0 and 1.0 × 108 rDNA copy/μl. There was a significant positive correlation between the number of parasites and the amount of I. salmonis rDNA. A survey using the qPCR assay indicated that infection by I. salmonis was present in 23 of 87 hatcheries; parasite loads were estimated to be between 50 and 750 parasites/g juvenile body weight. These results demonstrate that our qPCR assay enables the surveying of juvenile chum salmon reared in hatcheries for infection by I. salmonis. 相似文献
9.
Ichiro Honda Kaori Kikuchi Satoshi Matsuo Machiko Fukuda Hiroyuki Saito Hiromichi Ryuto Nobuhisa Fukunishi Tomoko Abe 《Euphytica》2006,152(1):61-66
We examined the effects of heavy-ion bombardment on mutagenesis in sweet pepper (Capsicum annuum L.). Dose–response studies indicated that 10 Gy irradiation of 12C or 20Ne ions on dry seeds is suitable for inducing mutations in plants. From 20Ne-irradiated M1 plants, putative mutants included two dwarf plants and one plant whose pericarp was yellow were isolated. Phenotypes of their M2 progeny were similar to those of the M1 plants and did not segregate. F1 plants resulting from reciprocal crosses between the mutants and wild-type plants showed the wild-type phenotype, but phenotypes of F2 and BC1F1 segregated at 1:3 (mutant:wild) and 1:1, respectively. These crossing experiments indicate that the three mutants have monogenic recessive mutations in nuclear genes. In light of these data, we discuss the effectiveness of using heavy-ion bombardment to mutate sweet peppers. 相似文献
10.
To evaluate the role of NH4 + assimilates in dark carbon fixation in roots in providing carbon skeletons expended for NH4 + assimilation, the rate of dark carbon fixation in roots was measured using NaH14CO3. The 14C-metabolites were analyzed in wheat (Triticum aestivum L.) plants grown in NH4 + media for various periods of time with or without methionine sulfoximine (MSX) treatment. The dark carbon fixation rate in the roots of wheat plants that had been grown with NH4 + for 1 d was approximately 6-fold higher than the rate in control roots. The stimulation of dark carbon fixation in NH4 +-grown plants, however, was not observed in MSX-treated roots. In the roots of NH4 +-grown plants, the concentration and 14C-Iabeling of acidic metabolites such as citrate and malate considerably decreased whereas those of basic metabolites, especially asparagine, increased noticeably. With MSX treatment, the incorporation of 14C into basic metabolites was negligible. In response to NH4 +, phosphoenolpyruvate carboxylase (PEPC) activity increased, and PEPC proteins accumulated in wheat roots. Neither activity nor amounts of PEPC in roots increased in the presence of MSX. These findings suggest that primary assimilation of NH4 + in roots is essential for the stimulation of dark carbon fixation, which coincides with the increased activity of root PEPC, to sufficiently replenish carbon skeletons necessary for NH4 + assimilation. 相似文献