阻燃处理木材燃烧残余物的热分解特征

为了弄清楚阻燃处理木材燃烧残余物的热分解特征,将阻燃处理木材在模拟的典型火灾中燃烧后,取距燃烧表面不同位置的试样,采用热失重法研究了阻燃处理木材燃烧残余物的热分解过程,结果表明:①阻燃处理木材及其燃烧残余物的热分解开始温度没有明显的差别,未处理木材燃烧残余物的热分解开始温度比未燃烧木材高;②阻燃处理木材中阻燃剂的热分解峰值温度为200℃,随着燃烧过程的进行,归属于阻燃剂的峰消失;③阻燃处理木材燃烧残余物热分解温度曲线中,在230℃附近归属于半纤维素的峰消失,在210～240℃出现了一个缓慢的肩;④阻燃处理木材及其燃烧残余物的质量损失速度曲线主峰温度比未处理木材及其燃烧残余物降低100℃,质量损失速度大幅度减少;⑤阻燃处理木材在600℃时的热分解残存质量比未处理木材显著增大,随着燃烧时受热温度的增高,燃烧残余物热分解的残余质量显著增大;⑥阻燃处理木材及其燃烧残余物的热分解温度区间,与未处理木材及其燃烧残余物存在显著差异.      

Strategies and engineering adaptions to disseminate SRI methods in large-scale irrigation systems in Eastern Indonesia

The system of rice intensification (SRI) developed in Madagascar has been controversial in part because there have been no large-scale, long-term evaluations of the impact of its alternative methods. This paper summarizes experience with the dissemination of SRI practices across eight provinces in Eastern Indonesia over nine seasons from 2002 to 2006 under a major irrigation project. The Decentralized Irrigation System Improvement Project (DISIMP) was financed by the Japanese Government with project management by a Nippon Koei consultant team. SRI has been introduced in Indonesia via several organizations and in different parts of the country starting in 2000. The evaluation reported here, made by the DISIMP technical assistance team, is based on data from 12,133 on-farm comparison trials that covered a total area of 9,429 ha. Under SRI management, average paddy yield increase was 3.3 t/ha (78%). This was achieved with about 40% reduction in water use, 50% reduction in chemical fertilizer applications, and 20% lower costs of production. The farmers whom DISIMP was assisting to take up SRI were usually cultivating their paddy fields individually within irrigation systems where it was difficult to reduce water applications as recommended for SRI. Accordingly, innovations had to be made in soil and water management to create relatively aerobic soil conditions so that farmers could get the more productive rice phenotypes expected from SRI practice. This article describes the modifications made to adapt SRI concepts, pointing to the value of introducing in-field ditches, which was confirmed through paddy tract surveys. This experience and analysis showed how SRI methods could be utilized within irrigation systems where water management was not (yet) tailored to SRI production practices. Subsequently, modifications in irrigation system management are being made to be more supportive of SRI cultivation.     

Effect of feeding rotifers enriched with taurine on the growth and survival of larval amberjack Seriola dumerili

The effect of feeding rotifers enriched with taurine on the growth performance and survival of larval amberjack Seriola dumerili was investigated. Rotifers were enriched with a commercial taurine supplement at four levels (0, 200, 400, and 800 mg/l). The larvae were fed the enriched rotifers in triplicate from 3 days post-hatch for 7 days under static conditions. The average taurine contents of the rotifers were 1.5, 2.7, 4.2, and 7.2 mg/g dry matter, respectively. The growth of the fish fed rotifers enriched with the taurine supplement at 800 mg/l was significantly (P < 0.05) improved compared with that of the fish fed the rotifers without taurine enrichment. The survival rate improved proportionally up to a taurine supplement level of 400 mg/l, but no significant differences in survival were observed among treatments. The fraction of the larvae with inflated swim bladders did not vary significantly between treatments. Taurine content in the whole fish body increased with the taurine level in the rotifers. These results suggest that taurine enrichment of rotifers is an effective method of enhancing the growth of amberjack larvae.     

Origin identification of dried seaweed product “nori” by PCR–RFLP analysis of Pyropia yezoensis in the internal transcribed spacer ITS-1 region

Nucleotide sequences in internal transcribed spacer (ITS)-1 region derived from dried nori products produced in Japan, China, and the Republic of Korea were compared. Thalli contained in the Japanese products were genetically homogenous, and their nucleotide sequences in ITS-1 were identical to those of the reference strains of Pyropia yezoensis f. narawaensis. In Chinese products, the thalli were related to P. yezoensis strain Minomiasakusa. In contrast, the thalli in the Korean products were genetically heterogeneous, and several different P. yezoensis strains and other Pyropia spp. were used for dried nori products. In some thalli produced in both China and Korea, the DNA sequences of the ITS-1 region were identical with that of Japan, suggesting that the cultivar strains might have been transplanted from Japan to China in recent years. The 432-bp-long nucleotide sequences in the ITS-1 region of thalli derived from Japanese origin were cleaved to two restriction fragments at 154 and 278 bp by cleavage of PCR-amplified products using MspI. Conversely, almost all of the corresponding sequences derived from China and Korea were lacking MspI or other restriction patterns, except for nori products from some areas that cultivate a closely related strain to the Japanese cultivar.     

Timing and frequency of egg-collar production of the moonsnail Euspira fortunei

Predation on the Manila clam Ruditapes philippinarum by the non-indigenous moonsnail, Euspira fortunei, has had severe impacts on clam fisheries in some localities in Japan. This paper aims to reveal when and how many egg collars E. fortunei produce during the egg-laying season. To investigate the frequency of egg-collar production, 13 pairs of E. fortunei were reared in aquaria with natural seawater flowing from July to December 2009. Each pair produced only one or two egg collars during 1 day in October; thereafter, no egg collars were produced. The timing of egg collar production, estimated from observational information by fishermen in the field from 2004 to 2010, varied among years. The period between September 1 and the day of the initial observation of egg collars was positively correlated with the average water temperature in August, suggesting that water temperature can be used to predict the timing of egg collar occurrence.     

Origin identification method by multiple trace elemental analysis of intermuscular bones in grilled eel products produced in Japan, China, and Taiwan

Trace elemental composition in intermuscular bones of grilled eel fillets was analyzed to discriminate the geographic origin of eel products derived from Japan, China, and Taiwan. The intermuscular bones were decomposed with nitric acid-hydrogen peroxide, and twelve elements (Li, Ti, V, Mn, Ni, Co, Zn, Rb, Sr, Ba, Pb, and U) were analyzed by inductively coupled plasma mass spectrometry. Trace elemental composition including six elements: V, Co, Sr, Ba, Pb, and U, in intermusucular bones were significantly different between Japanese domestic eels and imported eels from China and Taiwan. The average content of lead in Japanese eels was 1/4 to 1/6 that in eels imported from China and Taiwan. The data of elemental content in intermuscular bones were used for linear discriminant analysis, and two discriminant models were constructed. In the Japan–China discriminant model, the discriminant probabilities between Japanese origin and Chinese origin were 82.5 and 93.3 %, respectively. In the Japan–Taiwan discriminant model, the discriminant probabilities between Japanese origin and Taiwanese origin were 87.5 and 87.0 %, respectively. Therefore, trace elemental analysis is effective for country-of-origin identification of eels processed as grilled eel fillets.     

Partial characterization and ontogenetic development of pancreatic digestive enzymes in Japanese eel Anguilla japonica larvae

The pancreatic digestive enzymes, trypsin, chymotrypsin, lipase and amylase were partially characterized, and changes in their activities were examined during the initial ontogeny of Japanese eel Anguilla japonica larvae from 5 to 34 days post-hatching (dph). The pH optima of the eel larval enzymes were narrower than those other fish species; trypsin activity was highest at pH 9, chymotrypsin and amylase activities were highest at pH 7 and 8, and lipase activity was highest at pH 8 and 9. In an analysis of thermal profiles, the larval pancreatic enzymes had a high optimal temperature and high thermal stability, which are typical of fish from the tropics. At 12 and 13 dph, lipase activity and gene expression levels of trypsin (-a and -b), lipase and amylase decreased markedly, suggesting a marked change in larval metabolism at that time. These data could be useful in the development of artificial larval diets in Japanese eel.     

Effects of docosahexaenoic acid on growth,survival and swim bladder inflation of larval amberjack ( Seriola dumerili, Risso)

The effect of docosahexaenoic acid (DHA) on the growth performance, survival and swim bladder inflation of larval Seriola dumerili during the rotifer feeding period was investigated in two feeding experiments. Amberjack larvae at 3 day post hatching were fed rotifers enriched with (1) freshwater C hlorella (Chlo), (2) a mixture (2:1, v/v) of Chlo and DHA‐enriched C hlorella (DHA‐Chlo), (3) DHA‐Chlo and (4) DHA‐Chlo and commercial DHA emulsion, in triplicate for 7 days. The average DHA contents of the rotifers were 0.0, 0.4, 1.0 and 1.9 mg g^?1 DM respectively. The survival rate was improved by the enrichment of rotifers with DHA‐Chlo alone, and DHA‐Chlo and emulsion. Growth and swim bladder inflation of fish fed rotifers enriched with DHA‐Chlo were significantly (P < 0.05) improved, however, with increased levels of DHA further improvement was not found. DHA content in the larval whole body proportionally increased with the DHA level in the rotifers. These results suggest that DHA enrichment of rotifers is effective to improve the growth, survival rate and swim bladder inflation of amberjack larvae. The DHA requirement of amberjack larvae is estimated to be 1.5 mg g^?1 on a dry matter basis of rotifers.     

Small-radius turning performance of an articulated vehicle by direct yaw moment control

This paper reports the turning performance of an articulated vehicle in which applying direct yaw-moment control is applied to reduce the turning radius. In the proposed method, a braking force is applied to the inner tires when the articulation angle reaches its maximum in turning, which generates a yaw-moment around the vehicle's centre of gravity. The yaw-moment allows the vehicle to turn in a small radius. To evaluate the performance in tight turns, experiments were conducted using a wheel loader on paved ground. The vehicle's turning radius, yaw rate and side-slip angle were determined from the data measured using two global positioning systems and a fibre-optic gyro sensor. In addition, results of a simulation were compared with experimental results from a test vehicle. The turning radius at a braking pressure of 4 MPa was at least 0.41 m smaller than that of 0 MPa. Experimental and simulated results proved that generating a yaw-moment by applying one-sided braking forces during turning decreases the turning radius.