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21.
Ash produced from the combustion of livestock manure contains large amounts of phosphorus (P), which is an important resource as a fertilizer. Some studies have extracted and recovered P from incinerated biomass ash using inorganic acid or alkaline agents, which produce wastewater that requires treatment and is expensive due to the cost of chemicals. Livestock manure ash contains not only P, but also water soluble salts, which could be a negative influence on plant growth and shall be preferably removed from the recovered fertilizer. In this study, we removed salinity from cattle manure incineration ash by simple aqueous leaching, while retaining the P content. The optimal condition was a 20 min leaching time at a liquid/solid (L/S) ratio of 10 mL g-ash?1. Under this condition, over 90 % of Cl and 20 % of Na in the original ash was removed, while over 99 % of the P was retained in the leached residue. The leached residue met the fertilizer standard in Japan in terms of citrate soluble fertilizer components and contained few heavy metals. X-ray analyses of the ash indicated that Cl was mainly present as KCl in the original ash, while P was mainly present as Ca compounds in the ash.  相似文献   
22.
Although recent studies have demonstrated that calcification in a wide range of marine organisms is profoundly affected by CO2-induced ocean acidification, the mechanism of this phenomenon is still unclear. To clarify the effects of ocean acidification on the calcification process at the molecular level, we evaluated the expression of three biomineralization-related genes in the sea urchin Hemicentrotus pulcherrimus exposed under control, 1,000, and 2,000?ppm CO2 from egg to pluteus larval stage. We found that the expression of the gene msp130, which is proposed to transport Ca2+ to the calcification site, is suppressed by increased CO2 at pluteus larval stage. Meanwhile, expression of the spicule protein matrix genes SM30 and SM50 was apparently not affected. The results suggest that the combined effects of ocean acidification on the expression of skeletogenesis-related genes as well as the change in seawater carbonate chemistry affect the biomineralization ability of sea urchins.  相似文献   
23.
The bumblebee Bombus terrestris is not only an effective pollinator, but also a potential invasive alien species outside its native range. Recently, nearly 30% of queens of the Japanese native species Bombus hypocrita sapporoensis and B. hypocrita hypocrita were estimated to copulate with B. terrestris males in the field, suggesting that indigenous bumblebees could be genetically deteriorated through hybrid production with the introduced species. In this study, we evaluated hybrid production between the introduced B. terrestris and the indigenous B. hypocrita sapporoensis under laboratory conditions. The hatching rate of eggs derived from interspecific matings was 0% and 8.6% depending on the direction of the cross, which was significantly lower than that from intraspecific matings of B. terrestris (76.9%) and B. hypocrita sapporoensis (78.9%). Genetic studies using microsatellite markers revealed that both haploid and diploid individuals were present in the egg stage, whereas all hatched larvae were haploid. In addition, histological studies revealed that eggs derived from interspecific matings terminated development 2 days after oviposition. These results strongly suggested that eggs derived from interspecific matings are inviable due to post-mating isolation mechanisms. Mass release of exotic pollinators could cause serious population declines of native bumblebee species.  相似文献   
24.
A novel copolymer system has been synthesized using methyl hydroquinone diacetate (MHQDA), 1,4 naphthalene dicarboxylic acid (1,4 NDCA), and polybutylene terephthalate (PBT) using the melt polymerization technique. The optimum kinetic parameters pertinent to this system are reported in this study. A simple second-order reaction sequence summarizes catalyzed and uncatalyzed reactions between MHQDA, 1,4 NDCA, and PBT. The kinetic parameters for the copolymerization reaction were determined using a new second-order model. This technique was used to compute the moles of acetic acid generated in the polymerization process. The model was compared to that of the experimentally determined data. Close comparison (percentage error of less than 5%) was obtained between the experimental and theoretical data. The kinetic data support block copolyester formation. The thermal data also supports formation of block polymers.  相似文献   
25.
In social-insect colonies, cooperation among nestmates is generally stabilized by their high genetic similarity. Thus, fitness gained through cooperation drops quickly as the number of reproductive females (queens) increases. In this respect, wasps of the tribe Epiponini have attracted special attention, because the colonies have tens, or even hundreds of queens. It has been empirically or genetically confirmed that relatedness within nestmates can be elevated by a mechanism known as cyclical monogyny, under which new queens are produced only after the number of old queens is reduced to one. Another likely factor that can increase relatedness within nestmates under polygyny is comb partitioning by queens. If queens concentrate their egg laying on one or a subset of the available combs, then workers may be able to rear closer relatives by focusing their work on the comb where they emerged. Using microsatellite markers, we tested the hypotheses of cyclical monogyny and comb partitioning by queens increasing relatedness within nestmates under polygyny in the large-colony epiponine wasp, Polybia paulista. There were no significant differences between relatedness within combs and between combs, and thus we ruled out the possibility that each queen partitions reproduction between combs. However, as cyclical monogyny predicts, a lower effective number of queens contributed to queen production than to worker production. Cyclical monogyny explained well the observed smaller effective number of queens for new queens than that for workers, but failed to explain the stable relatedness values throughout colony cycles.Communicated by L. Keller  相似文献   
26.
Concentrations of paralytic shellfish poisoning (PSP) toxins in toxic dinoflagellate cells and in marine planktonic copepods were monitored during the bloom of Alexandrium tamarense in Hiroshima Bay, western Japan. Concentration of the toxins retained by copepods was a function of the ambient toxin concentration, i.e. the product of A. tamarense cell density and cellular toxicity. The toxin concentration in copepods increased with the increase of toxicants in the seawater then leveled off, but decreased significantly at higher concentrations. In the field, the maximum toxin concentration was 1.2 pmol ind-1, whereas in the laboratory, the copepod Acartia omorii accumulated a much higher concentration of PSP toxins (24 pmol ind-1). Feeding avoidance against Alexandrium tamarense and a shift to alternative food sources such as diatoms in the field might keep their toxin levels lower than their potentially maximum level. The copepod toxin levels in the field were not so high as to cause an instantaneous lethal effect on their predator fishes but may reach possibly lethal levels after a few days' continuous feeding. Overall toxin retention by copepods after 12 h feeding and 2 h starvation was only 2.5% of total ingested toxins, which suggested that a significant amount of toxins was released into the seawater. Measurements of toxin reduction and gut evacuation suggested that the toxins were removed through both fecal evacuation and metabolism (e.g. excretion, decomposition and transformation). The results, as a whole, imply that copepods can be a link for PSP toxin flux in both pelagic and benthic food webs and can also be a sink for toxins by metabolizing and removing them from the environment.Communicated by T. Ikeda, Hakodate  相似文献   
27.
Journal of Polymers and the Environment - The performance of two continuous UV/H2O2 photoreactors in series under unsteady-state condition is studied. An input–output dynamic model is...  相似文献   
28.
Objective: The objective of this study was to investigate whether the 5-point harness or the impact shield child restraint system (CRS) or both have the potential to cause chest injuries to children. This is determined by examining whether the loading to the chest reaches the internal organ injury threshold for children.

Method: The chest injury risk to a child occupant in a CRS was investigated using Q3 dummy tests, finite element (FE) simulations (Q3 dummy and human models), and animal tests. The investigation was done for 2 types of CRSs (i.e., the impact shield CRS and 5-point harness CRS) based on the UN R44 dynamic test specifications.

Results: The tests using a Q3 dummy indicated that although the chest deflection of the dummy in the impact shield CRS was large, it was less than the injury threshold (40 mm). Computational biomechanics simulations (using finite element FE analysis) showed that the Q3 dummy's chest is loaded by the shield and deforms substantially under this load. To clarify whether chest injuries due to chest compression can occur with an impact shield or with the 5-point harness CRS, 7 experiments were performed using Tibetan miniature pigs with weights ranging from 9.7 to 13 kg. Severe chest and abdominal injuries (lung contusion, coronary artery laceration, liver laceration) were found in the tests using the impact shield CRS. No chest injuries were present when using the 5-point harness CRS.

Conclusion: When using the impact shield CRS, the chest deformed substantially in dummy tests and FE simulations, and chest and abdominal injuries were observed in pig tests. It is possible that these chest injuries could also occur to child occupants sitting in the impact shield CRS.  相似文献   

29.

Energy and environmental issues have triggered the search for new sources of green energy alternatives in recent years. Biofuel production from renewable sources is widely considered one of the most sustainable alternatives for environmental and economic sustainability. Microalgae are currently being promoted as one of the most promising liquid biofuel feedstocks due to their rapid growth, high lipid production capacity, and carbon–neutral cycle. In this study, whole microalgae cells were utilized as raw material to produce solid biofuel, i.e., Bio-Coke, and this study aimed to investigate the possibility of microalgae Bio-Coke as an alternative to coal coke. The results show that Bio-Coke can be produced from microalgae in the temperature range of 80–100 °C. The apparent density is between 1.253 and 1.261 g/cm3, comparable to the apparent density of lignocellulosic Bio-Coke. Additionally, the calorific value is higher than the calorific value of lignocellulosic Bio-Coke and within the range of the calorific value of subbituminous coal. Therefore, microalgae Bio-Coke can be utilized to replace coal coke usage in the future.

  相似文献   
30.
The relation of interannual connection between Asian dust outbreaks and stratosphere-to-troposphere transport (STT) in spring was suggested by the dust and tritium variations in the Mount Wrangell ice core, Alaska in [Yasunari, T.J., Shiraiwa, T., Kanamori, S., Fujii, Y., Igarashi, M., Yamazaki, K., Benson, C.S., Hondoh, T., 2007. Intra-annual variations in atmospheric dust and tritium in the North Pacific region detected from an ice core from Mount Wrangell, Alaska. J. Geophys. Res., 112, D10208. doi: 10.1029/2006JD008121]. However, these impacts on the ice core site in each event scale have not been investigated. Hence, the present paper focuses on the material transport and deposition processes for further understanding these impacts on the ice core. The variations in dust and tritium concentrations in spring in an ice core taken at Mt. Wrangell, Alaska are explained by meteorological analysis and simulation of trajectories associated with Asian dust outbreaks and STT. Material transport and deposition at Mt. Wrangell are examined in two contrasting years (2001 and 2002). Dust and tritium concentrations both reached peak values in the early spring of 2002, while the dust peak occurred in early spring and the tritium peak occurred in late spring in 2001. Six severe East Asian transpacific dust storms over this period are modeled by forward trajectory and meteorologically analyzed. It is found that 5 of 6 events contributed to the ice core record in Alaska. Stratospheric air is also transported to the ice core site in most cases. Tritium deposition is found to have been suppressed in the cases of the 2001 dust storms due to lack of snowfall at appropriate times. Taken the detailed transport and deposition processes after the severe dust storms with atmospheric circulations into account, we can well explain spring dust and tritium variations in the Mount Wrangell ice core.  相似文献   
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