Hydration behavior and compressive strength of cement mixed with exploded wood fiber strand obtained by the water-vapor explosion process

Poor compatibility was found between exploded wood fiber strand (WFS) and cement due to the excessive presence of water-soluble degraded polysaccharides in extractives of exploded WFS obtained from weathered wood waste treated by the water-vapor explosion process (WVEP). This study presents some comparative results from a continuing investigation on the compressive strengths of exploded WFS–cement mixtures. Based on results previously obtained with the hydration test, the relation between hydration behavior and compressive strength of the mixture was explored. In addition, the effect of the curing age on compressive strength development of the mixture with selected additive chemicals was examined. The results supported the results of early studies with hydration tests indicating that adding MgCl₂ to the mixtures of exploded WFS mixed with quick-curing cement or ordinary Portland cement and a composite of MgCl₂ + CaO added to the mixture of exploded WFS and furnace-slag cement effectively improved the hydration behaviors; it greatly enhanced the compressive strengths of mixtures as well. Compressive strengths were strongly correlated to maximum hydration temperatures (T_max) of wood–cement mixtures influenced by the cement type, wood wastes (treated or not with WVEP), additive chemicals, and their content levels. The results also indicated that adding selected chemicals had no significant effect on compressive strength among the mixtures of exploded WFS mixed, respectively, with three types of cement at a curing age of 180 days. X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy were used to identify the hydration products and to probe the element distribution of the mixture in the wood–cement interface zone from a fractured surface.Part of this report was presented at the 52nd Annual Meeting of the Japan Wood Research Society, Gifu, April 2002     

Sodium bicarbonate protects uranium-induced acute nephrotoxicity through uranium-decorporation by urinary alkalinization in rats

To evaluate the effectiveness of sodium bicarbonate (SB) in removing uranium and protecting animals from uranium toxicity, we intramuscularly administered 1 mg/kg of uranyl nitrate to 8-wk-old male SD rats, and 20 min after administration of uranyl nitrate, the animals were given a single oral administration of SB at 0.1, 0.3 or 1 g/kg. The SB treatment at a dose of 0.3 g/kg or more raised the pH of the rats’ urine until 4 h after treatment, and it significantly reduced the uranium amounts in the kidneys at 1 day after treatment. In another experiment, rats were intramuscularly administered 1 mg/kg of uranyl nitrate, and 20 min later, the animals were treated with sodium bicarbonate (0.1 or 1 g/kg). The rats were autopsied at 1, 3 and 7 days after uranium treatment. High-dose SB resulted in a significant increase in urinary uranium excretion in the first 24 h and a reduction of uranium deposition in the kidneys and femurs, and it also significantly suppressed uranium-induced renal toxicity, as shown by both histopathology and clinical chemistry at 3 days after uranium treatment. Low-dose SB did not show such marked effects. Our findings demonstrated that the uranium decorporation effect of sodium bicarbonate was observed at the dosage showing urine alkalinization in rats and that decorporation effect of sodium bicarbonate might be beneficial if it is administered immediately after incorporation of soluble uranium.     

Effect of retinoic acid on gene expression profiles of bovine intramuscular preadipocytes during adipogenesis

To investigate genes involved in intramuscular adipogenesis in ruminants, 16 genes with dramatic variable expression were selected. These were selected from the differentiation‐ and proliferation‐phase libraries of our previous serial analysis of gene expression (SAGE) studies of a clonal bovine intramuscular preadipocyte (BIP) cell line. We harvested the BIP cells over 12 days after adipogenic stimulation with all‐trans retinoic acid (ATRA). Quantitative real‐time PCR confirmed the earlier SAGE study results of the expression patterns of 15 of the genes. On day 6, TG accumulation increased significantly in the BIP cells but was completely inhibited in the 3T3‐L1 cells (the monogastric reference). ATRA enhanced expression levels of six genes whereas it suppressed expression of eight genes on day 3 of adipogenesis in the BIP cells. Forty‐eight hours after transfection, the messenger RNA expression level of the adipose differentiation‐related protein (ADFP), encoded by one of the upregulated genes, in the ADFP small interference RNA (siRNA)‐transfected cells was 3.5% of that in negative control‐transfected cells. Also, 6 days after induction the TG level in the ADFP siRNA‐transfected cells was 21.8% lower than that in negative control‐transfected cells. This analysis of gene expression profiles after ATRA treatment will contribute to our understanding of the molecular mechanisms involved in bovine intramuscular adipogenesis.     

Oocyte growth in temperate basses: multiple forms of vitellogenin and their receptor

A full-length cDNA encoding a vitellogenin (Vg) receptor (VgR) was isolated and sequenced from a white perch, Morone americana, ovarian cDNA library. The perch expresses a single VgR that is structurally classified as an LR8 type (without an 0-linked sugar domain) and appears to be the only species observed to possess no splice variant of the receptor. We proposed a hypothetical model for ovarian lipid transfer in Morone species, one in which the `single VgR' transports Vg and other lipoproteins via a selective endocytotic pathway based on ligand affinity, in conjunction with a lipase-mediated pathway of fatty acid transport.     

Indirect evaluation of hardness and delamination strength of Akoya cultured pearl nacre based on UV fluorescence intensity

The durability of Akoya pearls is closely related to the mechanical strength of the nacre. Therefore, obtaining information about the mechanical strength of the nacre is very important in the quality control of pearls. The nacre of Akoya pearls is composed of aragonite contained within an organic matrix. The presence of the organic matrix provides mechanical strength and fracture toughness much higher than that of monolithic aragonite. In this study, we investigated the hardness and delamination strength of Akoya cultured pearls classified into four levels by “Gray Value (GV)”, a score given by a non-destructive inspection method based on UV fluorescence intensity that provides an indication of the condition of the nacre’s organic components. Pearl hardness decreased significantly with decreasing GV. Furthermore, delamination strength of the pearl surface layer was very low when the GV was very low. These results suggest that the GV indirectly represents the mechanical strength of the nacre and could be used as a non-destructive quality-control method to maintain the quality of pearls used as jewelry.

     

Development of height curves for Japanese larch in relation to GIS-derived site index

The objectives of this study were: (1) to relate the height growth pattern to the GIS-derived site index, (2) to construct various types of polymorphic height curves, and (3) to select the most accurate height curve for Japanese larch (Larix kaempferi). A total of 14 dominant trees were felled for stem analysis. Richards' function was first fitted to the height/age dataset recorded from stem analyses of 14 trees, and its parameters (i.e., A, k, and m) were then estimated for each sample tree. The relationship between parameter A and the GIS-derived site index was significant, while that of parameters k and m were not significant. The 12 height curve equation forms developed from the Richards' function were then fitted to the dataset consisting of 563 observations of height, age, and GIS-derived site index derived from 14 trees. All height curves were unbiased and provided an equally good fit. The shape of the height curves differed among sites of different site indices. These results indicated that Richards' function was sufficiently flexible to represent the polymorphic height growth pattern of Japanese larch. Finally, the best-fit height curve was selected so that accurate height growth predictions would be possible at any given age and site.     

Long Term Trend of Chemical Constituents in Tokyo Metropolitan Area in Japan

In recent years, acid rain has been a social problem all over the world. In Japan, it is also a big problem especially in the metropolitan area. Then, we have measured major ions such as H⁺, Na⁺, NH₄ ⁺, K⁺, Mg²⁺, Ca²⁺, Cl^?, NO₃ ^?, and SO₄ ^2? in precipitation and dry deposition samples which had been collected at 9 sampling sites at Hiyoshi, Mita, Kashiwa, Shiki, Fujisawa, Yokosuka, Mitaka, Hachiouji, and Ashikaga in Tokyo Metropolitan area for 10 years since 1990. The average pH of precipitation in their sites was 4.56 (n=1906). As the results of multiple regression analysis showed that pH of precipitation was determined by 5 ions such as NH₄ ⁺, nssCa²⁺(non sea salt calcium), nssCl^?(non sea salt chloride), NO₃ ^?, nssSO₄ ^2?(non sea salt sulfate) in the most of the sampling sites. Therefore, it is very important to investigate the behavior of these ions to understand the acidification of rain in Tokyo Metropolitan area. In this study, a long term trend of each ion concentration in precipitation and wet deposition was also investigated the base on the data we had observed at 7 sites for 10 years by the statistical method.