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Prediction of soil characteristics over large areas is desirable for environmental modeling. In arid environments, soil characteristics often show strong ecological connectivity with natural vegetation, specifically biomass and/or canopy cover, suggesting that the soil characteristics may be predicted from vegetation data. The objective of this study was to predict soil infiltration characteristics and horizon (soil layer) thickness using vegetation data for a large-scale water balance model in an arid region. Double-ring infiltrometer tests (at 23 sites), horizon thickness measurements (58 sites) and vegetation surveys (35 sites) were conducted in a 30 km × 50 km area in Western Australia during 1999 to 2003. The relationships between soil parameters and vegetation data were evaluated quantitatively by simple linear regression. The parameters for initial-term infiltration had strong and positive correlations with biomass and canopy coverage (R2 = 0.64 − 0.81). The horizon thickness also had strong positive correlations with vegetation properties (R2 = 0.53 − 0.67). These results suggest that the soil infiltration parameters and horizon thickness can be spatially predicted by properties of vegetation using their linear regression based equations and vegetation maps. The background and reasons of the strong ecological connectivity between soil and vegetation in this region were also considered.

Anodic oxidation of trichloroethene (TCE), a toxic chlorinated water contaminant, is carried out using Ti/IrO 2 –Ta 2 O 5 electrode. The redox behaviour of TCE molecule, fouling of electrodes and generation of oxygen was studied by cyclic voltammetry. The studies on cyclic voltammetry reveals that the TCE oxidation takes place directly on electrode surface at the potential region above 0.3 V vs. SCE by direct electron transformation and oxygen evolution from anode. The effect of the electrolyte, pH of the aqueous medium and applied current density on the mineralization behaviour of TCE is also investigated. The degradation of TCE is monitored in terms of TOC and TCE concentration with electrolysis time and corresponding chloride evolution. The complete mineralization of TCE is achieved using Na 2 SO 4 as supporting electrolyte. Conversely, the mineralization of the TCE molecule was observed to be poor because of the electrode fouling in the presence of NaNO 3 . The dechlorination of TCE is found to increase with electrolysis time and the complete dechlorination is observed at all I appl studied. The kinetics of TCE degradation was found to follow pseudo-first order reaction whose rate constant was calculated to be 0.0081 cm s −1 at I appl value of 13.39 mA cm −2 . The performance of Ti/IrO 2 –Ta 2 O 5 anode was proved to be better compared to Pt under similar experimental conditions.

The removal of Cr(VI) from aqueous solution using the seeds of the plant species Strychnos potatorum was studied. The plant is popularly known as Nirmali tree, grown all over India. The dried Nirmali seeds were powdered and used as adsorbent. The SEM-EDX and FT-IR spectrum of the adsorbent revealed that the powder is fibrous in nature and contains functional groups such as OH and COOH. The zeta potential measurements indicated negative surface charge beyond the pH of 1.50. Batch type experiments were conducted to study the influence of pH and initial Cr(VI) concentration on the removal of Cr(VI) from aqueous solutions. Maximum removal of Cr(VI) was observed at pH 1.0. The adsorption equilibrium was attained within a sort contact time of 4 min and the maximum uptake of Cr(VI) was found to be 59 mg g-1. The influence of anions such as Cl-, NO3-, and SO42- on Cr(VI) removal was investigated and found that the removal was slightly affected in the presence of NO3- and SO42-. The rate of removal of Cr(VI) was found to obey pseudo second order rate equation. The high free energy value of adsorption (ΔG = -137 kJ mol-1) indicated that the adsorption of Cr(VI) on Nirmali seed powder was mainly attributed due to chemical and electrostatic interaction. © 2011 American Institute of Chemical Engineers (AIChE).

Tricalcium aluminate (Ca3Al2O6, C3A) containing 0–5% of Sn was synthesized by solid-state method, and the products were characterized by XRD technique. Differential thermo-analytical technique (DTA) along with X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) were applied to study the hydration behaviour of different C3A samples with and without the presence of gypsum. Results indicate that C3A can accommodate small amount of Sn in its structure and remaining amount forms SnO2. Hydration studies of the synthesized C3A shows that the additions of 0.5 and 1% Sn increase and 2% Sn decrease the reactivity of C3A at the initial period (

The pervaporation performance of heat-treated PVA membranes with varying degrees of saponification was examined for the separation of ethanol from mixtures with n-heptane, which simulates the on-bo...

In the present study, a magnetically separable photocatalyst (TiO2/SiO2/Fe3O4) has been prepared and used for the photooxidation of methyl orange (MO) dye. The effects of various reaction conditions such as dye concentration, catalyst dose, and pH on the reaction rate were investigated to enhance the photooxidation process. Thephotocatalytic oxidation of MO was found to follow half-order kinetics. The optimum reaction conditions were found to be a 2000 ppm TiO2 catalyst dose in an acidic medium. A higher catalyst load had no effect on the degradation rate. The dye concentration negatively affected the reaction rate because of the reduced light transmittance inside the photoreactor. The catalyst could be reused several times with nearly the same activity and thus the final cost of the treatment process could be reduced.

Network coordinates (NCs) enable the efficient and accurate estimation of network latency by mapping the geographical relationship among all nodes to Euclidean space. Many researchers have proposed NC-based strategies to reduce the lookup latency of distributed hash tables (DHTs). However, these strategies are limited in the improvement of the lookup latency; the nearest node to which a query should be forwarded is not always included in the consideration scope of a node. This is because conventional latency improvement strategies assign node IDs independent of the underlying physical network and still have the possibility of detour routing. In this paper, we propose an NC-based method of constructing a topology-aware DHT by Proximity Identifier Selection (PIS/NC). PIS/NC constructs a logical ID space of a DHT from the Euclidean space constructed by NCs; a node ID corresponds to the network coordinate of the node. By doing this, the consideration scope of a node always contains the nearest node, thus, we can expect a great reduction in lookup latency. Unlike the conventional PIS strategy that poses unavoidable issues due to uneven ID distribution, PIS/NC tries to moderate these issues by a simple optimization, provided by a PIS/NC stabilizer. The PIS/NC stabilizer detects an uneven distribution of node IDs locally, and then recalculates some IDs so that the unevenness is moderated. As case studies, this paper presents Canary and Harpsichord, which are PIS/NC-based CAN and Chord, respectively. Simulation results show that PIS/NC-based DHTs improve lookup latency. Under the environment using the Transit-Stub model, where SAT-Match and DHash++ are only able to reduce the median lookup latency by 19% of CAN and 9% of Chord, respectively, Canary and Harpsichord reduce it by 40% and 35%, respectively. We also verify that the PIS/NC stabilizer moderates the non-uniform distribution of node IDs.

Afforestation is one of the most promising methods for the fixing of carbon dioxide. In this research, a target area of unused land, not competitive with food production and with a large area, was selected in the arid land near Leonora in Western Australia. It was necessary to select suitable tree species for afforestation in the target arid area. The objective of this work was to establish a method for the estimation of the amount of water used per net carbon intake. In this study, a method for the estimation of the water use efficiency (WUE) using nutrient tracers is suggested and established. Calcium was the most suitable nutrient for use as a tracer for this estimation method. The sampling strategies for the measurements were decided, and the nutrient concentrations in the tree organs and sap and content of carbon were determined. In particular, a method through which the calcium content in the sap is corrected using the calcium concentration in the organs of a tree was examined. It was confirmed that the WUE value obtained with this method was comparable to those determined by conventional methods. Finally, it is suggested that the present method for WUE determination is characterized by the advantages of short measurement terms and low cost.

Biomass utilization is one of the most important methods for global warming mitigation from the viewpoints of both carbon sequestration and carbon-neutral energy use. Carbon sequestration potential should result from phytomass stock expansion, and in this study, the potential of phytomass stock expansion due to afforestation/rehabilitation with additional special water management was estimated by using several sets of global geographical information systems (GIS) data. The estimation was conducted under unified conditions for all the world areas by using a computer program based on the GIS data. The carbon sequestration potential of a land area was assumed to be primarily determined by its precipitation level if the area satisfied certain meteorological and geographical conditions for phytomass stock expansion, such as land use, temperature, slope, and soil type, and the sensitivities of these conditions were studied. The carbon sequestration potential due to regular afforestation/rehabilitation was estimated to be about 169 GtC in the world, and the effective regions for carbon sequestration were Brazil, etc. On the other hand, the increase in the carbon sequestration potential due to the additional special water management was estimated to be about 21 GtC in the world, and the effective regions were Saudi Arabia, west Australia, etc.

A shallow saline water solar pond is theoretically modeled and experimentally investigated using a carboxymethyl cellulose gel layer as an evaporation suppressor. Saline water shallow solar ponds are quite frequently encountered in deserts/arid areas and are considered potentially harmful to the soil, with no known usefulness. The influences of various parameters on the efficiency of the ground shallow solar pond are also investigated theoretically and experimentally. The present investigation shows that a very thin layer of gel is capable of increasing the thermal energy retaining capacity of the ponds, which can be harnessed by several available technologies.

An afforestation field experiment studying Eucalyptus camaldulensis, E. torquata, and Casuarina obesa with five different irrigation intervals was set up in an arid region in Western Australia. The irrigation intervals used were 2 weeks, 1 month, 3 months, 6 months, and no irrigation, which resulted in water supplies of 1243, 895, 511, 423, and 313 mm/y averaged over the experimental period, respectively. The average growth rates of C. obesa in sections with 2-week and 1-month irrigation intervals were 1.9 and 1.3 kg/(m2·y), respectively, about double those of E. camaldulensis. However, the average growth rate of C. obesa was lower than E. camaldulensis in sections with less irrigation. For C. obesa, water use efficiency was highest with a 2-week irrigation interval and quickly decreased with decreasing water supply. For E. camaldulensis, it was highest with a 1-month irrigation interval and did not decrease as much as that of C. obesa with decreasing water supply. We concluded that C. obesa has a high water use efficiency with a water supply more than 890 mm/y. E. camaldulensis, however, can grow more efficiently than C. obesa when the water supply is less than 510 mm/y. E. torquata is unsuitable for arid land afforestation.

Integrated coal gasification combined cycle (IGCC) technology is being promoted to make better use of energy resources, and an entrained-flow gasifier is a key item of equipment in the process due to its high gasification efficiency, smooth discharge of molten ash, etc. The temperature and heating rate under entrained-flow gasification conditions are very high, and these two parameters can influence the gasification reactivity of a char with CO2. Therefore, the clarification of characteristics and mechanisms of char gasification under conditions close to entrained-flow gasification is very important. To obtain a valid kinetics of char gasification, it is necessary to clarify the effect of heating rate during pyrolysis on char reactivity. The effect of heating rate during pyrolysis on the gasification reactivity of three types of chars in CO2 was investigated experimentally at elevated temperatures in a novel fluidized bed. It was shown that even at elevated temperatures, the heating rate has significant influence on the char reactivity during gasification. A higher heating rate during pyrolysis leads to higher char reactivity of gasification, however it has only limited effect on the activation energy of char gasification with CO2. The char reactivity is closely related to its specific surface area and pore volume. The high reactivity of a char derived from pyrolysis at a high heating rate is most likely due to its enhanced porous structure as a result of the rapid release of volatile matter at a high heating rate. The effect of heating rate during pyrolysis on char reactivity is pronounced at low temperatures, and is very different for various coal types, i.e. very pronounced for a low-rank coal. The gasification reactivity of a char is related to both the char pore structure and temperature, which suggests that even at elevated temperatures the gasification of a char with CO2 is controlled by both chemical reaction and diffusion inside the particles. Our results demonstrate that it is necessary to derive the gasification kinetics of a char at a high heating rate to obtain valid kinetic equations for an entrained-flow gasifier. Copyright © 2010 Curtin University of Technology and John Wiley & Sons, Ltd.

Selective methanation of CO in the reformate gas (CO/CO2/H2/H2O = 0.175/17.9/70.9/11.1) proceeded over Ru catalysts supported on metal oxides and zeolites. CO was selectively methanated at wide temperature ranges (200–275 °C) over Ru/γ-Al2O3, Ru/TiO2 Ru/H-Y and Ru/H-beta catalysts. Higher Ru contents in Ru/γ-Al2O3 improved the selective CO methanation rate.

We clarified the relationship between environmental factors and the growth of seven Eucalyptus species and Casuarina obesa planted at an afforestation site in southern Western Australia's wheatbelt. The site consisted of abandoned fields damaged by secondary salinity associated with waterlogging. Afforestation is expected to progressively rehabilitate the land, which has a slight slope generating a large environmental gradient. During the rainy season, waterlogging (soil becoming saturated with water) occurred at the lower part of the site, but not at the higher part. The level of salt in the soil (EC1:5) increased gradually from higher to lower ground (0.34—2.7 dS m-1). Tree size and growth rate were negatively related to waterlogging intensity and showed small values at the lower part of the site, with only a slight effect on tree size and growth rate. Moreover, interspecific differences in size and growth rate were observed. Eucalyptus sargentii and E. occidentalis had larger sizes and faster growth rates than E. camaldulensis. Trees planted under waterlogging conditions at the lower part of the site are likely to fail due to poor growth; therefore, afforestation should begin on higher ground where trees would experience normal growth, and in doing so, reduce the soil water content to rehabilitate the land. Improvement of water balance through afforestation would confirm the benefits of appropriate agroforestry management.

近年の地球温暖化の対策技術の一つとして，乾燥地大規模植林による大気中CO2固定システムの構築が試みられている．乾燥地・半乾燥地は，地球上の陸地の約1/3に相当し，絶対的に雨水が不足しているために土地生産性が極端に低い．しかし，乾燥地では，多くの雨水が土壌に浸透せずに表面流出し，流れ込んだ集水池で無駄に蒸発している．表面流出水は，集めて植物の根域に浸透させることで植物成長に利用可能な水となる．それゆえ，乾燥地植林を行うには，植物利用可能な雨水（表面流出水）を有効利用できる適切な植林地選定が必要とされる．本報告では，西豪州乾燥地に設定した数km程度の流域内での水挙動を表現することを目的とした独自の表面流出モデルの構築を行った．10 mメッシュでの数値計算を行うにあたり，計算誤差を無視するのに必要とされる時間差分値の限界値を策定した．ついで，乾燥地での降雨時の流出挙動の実測値を計算結果と比較することにより，本モデルの二つのフィッティングパラメータを決定した．以上により，流域内の水挙動を表現するモデルを構築できた．

As demand for high fidelity multimedia content has soared, content distribution has emerged as a critical application. Large multimedia files require effective content distribution services such as content distribution networks (CDNs). A recent trend in CDN development is the use of peer-to-peer (P2P) techniques. P2P-based CDNs have several advantages over conventional non-P2P-based CDNs in scalability, fault resilience, and cost-effectiveness. Unfortunately, P2P-based content distribution poses a crucial problem in that update propagation is quite difficult to accomplish. This is because peers cannot obtain a global view of replica locations on the network. There are still several issues in conventional approaches to update propagation. They degrade the scalability, the fault resilience, and the cost-effectiveness of P2P-based content distribution, they also consume the network bandwidth, or take a long time. In this paper, we propose the speculative update, which quickly propagates an update to replicas with less bandwidth consumption in a pure P2P fashion. The speculative update enables a fast update propagation on structured P2P-based CDNs. Each server attempts to determine the directions in which there will be replicas with a high probability and speculatively relays update messages in those directions. Simulation results demonstrate that our mechanism quickly propagates an update to replicas with less bandwidth consumption. The The speculative update completes update propagation as fast as the simple gossip-based update propagation even with up to 69% fewer messages per second. Compared to the convergence-guaranteed random walk, the speculative update completes an update propagation faster by up to 92%.

Many services rely on the Internet to provide their customers with immediate access to information. To provide a stable service to a large number of customers, a service provider needs to monitor demand fluctuations and adjust the number and the location of replica servers around the world. Unfortunately, flash crowds make it quite difficult to determine good number and locations of replica servers because they must be repositioned very quickly to respond to rapidly changing demands. We are developing ExaPeer, an infrastructure for dynamically repositioning replica servers on the Internet on the basis of demand fluctuations. In this paper we introduce ExaPeer Server Reposition (EPSR), a mechanism that quickly finds appropriate number and locations of replica servers. EPSR is designed to be lightweight and responsive to flash crowds. EPSR enables us to position replica servers so that no server becomes overloaded. Even though no dedicated server collects global information such as the distribution of clients or the load of all servers over the Internet, the peer-to-peer approach enables EPSR to find number and locations of replica servers quickly enough to respond to flash crowds. Simulation results demonstrate that EPSR locates high-demand areas, estimates their scale correctly and determines appropriate number and locations of replica servers even if the demand for a service increases/decreases rapidly.

現在，大気中二酸化炭素濃度の増加による地球温暖化が問題となっており，その対策として西豪州半乾燥地における大規模植林が試みられている．対象地での積極的な対策としては，対象地における表面流出水の有効利用が考えられているが，その期待される表面流出水量は未知であり，同時に進められている数値計算の比較可能なデータは皆無である．そこで本研究は，年間降水量200 mmの対象地における表面流出の実測を行い，表面流出率の定量的把握，および植林地選定を目的とした表面流出モデルの検証の為の水収支データ取得を行った．その結果，29 mmの降雨では表面流出率17.5%であることが実測により得られ，対象地における植林への表面流出水の有効利用量が定量的に明らかになった．

China has already become the second largest oil consumption country following the United States in the world. Furthermore the Chinese oil demand keeps increasing at the annual growth rate larger than ten %. The oil import dependence of China is forecasted to be 64.5% in 2020. It will be inevitable that China with rapid increase in demand and Japan with about 100% import rate of crude oil become competitors in energy secure field, especially oil. However, the future cooperation is expected in the areas of conservation of energy, new energy development and energy related environmental conservation. Because the energy related technologies such as desulfurization in the coal and oil combustion/conversion, coal liquefaction, energy conservation in the mining and manufacturing, traffic transportation and construction areas, the reduction of carbon dioxide emission, new and atomic energy development and so on are advanced fields of Japan and the related technologies and know-how are accumulated in Japan, not only the simple technology transfer to China, but also business opportunity for a Japanese enterprise will increase through cooperation in the above areas.

二酸化炭素問題の対策技術の一つとして，資源量が豊富である岩石の風化反応に注目した．しかしながら，岩石を利用する対策技術では，その風化反応速度は遅く，その反応速度がネックになると予想される．本研究では，基礎的知見を得るために，様々な珪酸塩鉱物について，速度論的検討を行った．実験は，二酸化炭素飽和水を用意し，粉末状の鉱物を加え，恒温槽内（25°C）で撹拌を行いながら，二酸化炭素を流し続けた．そして，一定時間経過後，一定量採取し，手早くろ過し，ろ液からの再沈澱を防ぐために硝酸を加え，液中の主成分元素を定量した．溶解反応は，瞬間的な溶出過程・一次的な濃度増加過程・風化反応の平衡からなることがわかった．さらに，風化反応の律速段階は，鉱物表面上に存在することから，風化反応速度を表面積当りの溶解速度として求めた．速度は2.1×10−5–7.3×10−4 mol/（m2· h）の範囲であり，中でもCaを主成分とするCaSiO3，CaCO3の溶解速度が速いことがわかった．

本論文では，武蔵野市で行われた廃プラスチックの混合焼却試験の結果を報告する．既存設備で廃プラを燃やすとダイオキシンなど有害ガスが発生することが危惧される．一方，埋め立て場所の不足の点から，プラスチックごみについても焼却処理したいとの行政側の意向がある．本試験は，混合焼却によりダイオキシン類など有害ガスがどのような挙動を示すかを計測し，実操業時での混合焼却の可否の判断のために行われたものである．ダイオキシン類およびその前駆物質の抑制にあたっては，燃焼過程での生成抑制が最優先されるべきで，次に排ガス処理装置で高効率除去プロセスが要求される．試験により，ボイラー出口のダイオキシン濃度は，混合焼却ごみ中のプラスチック含有率とは明らかな関係を示さなかった．ボイラー出口においてダイオキシンの濃度が最も低かった1点を除き1.2–2.3 ng-TEQ/m3 Nであったが，バグフィルタ通過後のダイオキシン濃度はその1%程度まで減少した．煙突からのダイオキシン類の排出濃度は0.12–0.33 ng-TEQ/m3 Nであり，2002年12月からの既設施設の2 t/h以上4 t/h未満の規模の焼却炉に対する新基準値である5 ng-TEQ/m3 Nを満足していた．したがって，廃プラを燃やしても，必ずしもダイオキシン類の発生の増加がみられるとはいえないとの結論を得た．廃プラ混焼により，高温化による炉寿命への影響やHCl除去費用の増大の可能性は残るものの，NOx等のほかの有害ガスについては，顕著な増大は認められなかった．武蔵野市ではこの試験結果に基づき，2003年10月から廃プラを焼却することとした．

Arsenic removal from water/wastewater has been the subject of top priority among researchers/industries in recent years due its notorious characteristics. A novel technique of electrocoagulation has been attempted in the present investigation to remove arsenic from aqueous solution. Experiments were carried out in a batch electrochemical reactor using aluminum and mild steel sacrificial anodes. The mechanism of electrocoagulation has been modeled using adsorption isotherm kinetics. Experimental runs were designed by response surface methodology and the influence of combined effects of operating parameters on arsenic removal has been critically examined.

Afforestation of arid land is a promising countermeasure against global warming. We had previously found, through modeling and mass balance analyses of an arid land afforestation experimental project in Western Australia, that a significant amount of litter could have been physically removed from the floors of natural forests. In order to analyze litter carbon dynamics in depth, we investigated the actual mobility of litter in several natural forests in Sturt Meadows in an arid region of Western Australia, and estimated the difference between the removal rate of leaf and woody (twigs and branches) litter on the forest floor. Then we redeveloped a litter carbon dynamics model by incorporating physical removal of litter to show the different mobilities of leaf and woody litters. We also analyzed carbon balances and the effect of differential litter mobility on litter carbon dynamics. Except for twigs in one plot in a high density forest, 29–100% of leaf litter and 10–100% of woody litter was removed annually, demonstrating the physical removal of litter in these natural forests. The main cause of litter removal was wind, not flooding. Decreases in leaf and woody litters could be approximated as first order decay functions in most plots; first order decay or disappearance rate constants were then determined. Estimated disappearance rate constants of leaf and woody litter ranged from 0.19 to 11 and 0.11–12 year −1 , respectively; most of the constants ranged from 0.19 to 2.0 and 0.11–0.74 year −1 , respectively. Based on the disappearance rate constant, the mobility of woody litter was estimated to be roughly 20% that of leaf litter, confirming that climatic factors move leaves more easily than twigs. The improved model, which took into account the different mobilities of leaf and woody litters, showed that annual physical removal of litter reached 70–82% of the annual litter fall in Acacia aneura forests, and that roughly 40–60% of the existing litter was removed annually from all sites. Incorporating into the model the difference in mobilities of leaf and woody litters showed that the ratio of annual litter removal to annual litter fall increased about 10% points compared with the assumption of that both litter types had equal mobility.

In a unique fluidized-bed reactor, the gasification reactivity with steam of chars derived under various conditions was investigated at elevated temperatures. It was revealed that, similar to char-CO2 gasification, even at elevated temperatures, the gasification rates in steam were very different between different coals. The gasification rate of char with steam was very different from that of raw coal. A longer pyrolysis time led to lower reactivity of char during char gasification with steam. No significant influence of pyrolysis time on the temperature dependence of gasification reactivity (i.e., activation energy for a char) was identified. The reaction rate for coal had a tendency to level off at a high temperature for simultaneous pyrolysis/gasification experiments, which was probably caused by the ash fusion in a reducing atmosphere. Generally, the activation energy of char gasification with steam, was lower than that with CO2 gasification. Moreover, the former activation energy in the low-temperatu...

Removal of arsenic from aqueous solution was carried out using electrocoagulation. Experiments were conducted using mild steel sacrificial anode covering wide range in operating conditions to assess the removal efficiency. The maximum arsenic removal efficiency was recorded as 94% under optimum condition. The electrocoagulation mechanism of arsenic removal has been developed to understand the effect of applied charge and electrolyte pH on arsenic removal efficiency. Further the experimental data were tested with different adsorption isotherm model to describe the electrocoagulation process.

Relationship between sound pressure in a sonochemical reactor and degradation rate of organic compounds, p-chlorophenol and p-nitrophenol, was investigated. Reaction rates were analyzed as first-order reaction. As a result, linear relationship was shown for each compound. Slope indicating the first reaction rate constant was remarkably affected by the position of the reaction flask. The sound pressure profile was measured and the relationship between the averaged pressure in a flask and the rate constant was shown. The relation was found to be remarkably different between the two. The threshold values were observed as 67kPa for p-chlorophenol and 22kPa for p-nitrophenol, respectively. From these results, it was shown that nature of compounds affects the dependency on sound pressure. On a etudie la relation entre les vitesses de degradation des composes organiques, le p-chlorophenol et le p-nitrophenol, et la pression acoustique dans une reaction sonochimique. Les premieres constantes de vitesse de reaction se sont averees fortement influencee par la position de la cellule de reaction dans notre installation. Le profil de pression acoustique dans l'installation a ete mesure et la relation entre la pression moyennee dans la cellule et la constante de vitesse a ete determinee. On a trouve que la relation etait significativement differente entre les deux composes et que les valeurs seuils etaient de 100 kPa pour le p-chlorophenol. On a montre egalement que la nature des composes avait une influence sur leur dependance a la pression acoustique.

The TiO2/SiO2/Fe3O4 (TSF) photocatalyst was used for the treatment of synthetic dyes wastewater. Different operating conditions such as catalyst load, pH and dye concentration were investigated in order to determine the optimum operating conditions. The optimum operating conditions were found to be 2500 ppm TiO2 photocatalyst dose and pH 3. More catalyst dose led to reduction in rate of reaction due to aggregation of photocatalyst as well as increasing of opacity inside photoreactor. Acidic medium favored adsorption of studied dyes on photocatalyst, and hence increased the rate of reaction. Under optimum conditions, complete decolourization and degradation of the organic dyes could be achieved within less than 45 min. Kinetic studies indicated that rate of reaction depends on three parameters: photocatalyst load, dye concentration and transmittance inside photoreactor. TSF photocatalyst could be used several times with nearly the same efficiency. The reuse of the photocatalyst is supposed to decrease the final cost of the treatment process.

The new methacrylic monomer, 3,5-dimethoxyphenyl methacrylate (DMOPM) was synthesized by reacting 3,5-dimethoxyphenol dissolved in ethyl methyl ketone (EMK) with methacryloyl chloride in presence of triethylamine as a catalyst. The homopolymer and copolymers of DMOPM with glycidyl methacrylate (GMA) were synthesized by free radical polymerization in EMK solution at 70 ± 1 °C using benzoyl peroxide as a free radical initiator. The copolymerization behaviour was studied in a wide composition interval with the mole fractions of DMOPM ranging from 0.15 to 0.9 in the feed. The homopolymer and the copolymers were characterized by FT-IR, 1 H NMR and 13 C NMR spectroscopic techniques. The solubility was tested in various polar and non-polar solvents. The molecular weight and polydispersity indices of the polymers were determined using gel permeation chromatography. The glass transition temperature of the copolymers increases with increase in DMOPM content. The thermogravimetric analysis of the polymers showed that the thermal stability of the copolymer increases with DMOPM content. The copolymer composition was determined using 1 H NMR spectra. The monomer reactivity ratios were determined by the application of conventional linearization methods such as Fineman–Ross ( r 1 = 0.520, r 2 = 2.521), Kelen–Tudos ( r 1 = 0.629, r 2 = 2.554) and extended Kelen–Tudos methods ( r 1 = 0.600, r 2 = 2.502).

This research is mainly directed toward the development of hardness of glass ceramic by adding different amounts of ZrO 2 to the glass and by applying different heat-treatments. Differential thermal analysis (DTA), X-ray diffraction (XRD) and Scanning electron microscope (SEM) were used to study the crystallization behaviour of the glass samples. The only observed crystalline phases were tetragonal and monoclinic zirconia. Hardness was found to increase by increasing time and temperature of heat-treatment due to the formation of monoclinic phase as a result of the martensitic reaction. This transformation opposes crack opening.

The complexes [Co(N^O)2] (1) and [Cu(N^O)2] (2) {N^O = η2-(N,O) coordinated 2-pyrazinecarboxylic acid} have been synthesized and characterized by elemental (including metal) analyses, FT-IR spectroscopy and powder X-ray diffraction. The molecular structure of complex 2 was determined by single X-ray crystallography. In the molecule, the Cu atom occupies the center of a square planar geometry, which consists of two trans-O atoms and two trans-N atoms of two 2-pyrazinecarboxylic acid ligands. The complexes 1 and 2 were well encapsulated into zeolite–Y super-cage to yield the corresponding zeolite–Y encapsulated metal complexes, abbreviated herein as [Co(N^O)2]–Y (3) and [Cu(N^O)2]–Y (4). Similarly, the metal complexes 1 and 2 were immobilized on alumina and organically modified silica surfaces to lead to the formation of immobilized metal complexes [Co(N^O)2]–Al2O3 (5); [Cu(N^O)2]–Al2O3 (6); [Co(N^O)2]–AMPS (7) and [Cu(N^O)2]–AMPS (8) (AMPS = aminopropyl silica). Elemental (including metal) analyses, FT-IR spectroscopy, powder X-ray diffraction and thermal analysis have been used to characterize these materials. The catalytic activity of all the catalysts 1–8 towards the oxidation of cyclohexene into different chemically and pharmaceutically important products were evaluated under homogeneous and heterogeneous conditions. In order to obtain a maximum conversion of cyclohexene, the reaction parameters, like reaction temperature and time, were optimized. Under the optimized conditions, a maximum of 90.47% cyclohexene conversion was achieved with [Cu(N^O)2]–Y (4) with a 1:2 molar ratio reaction of cyclohexene and H2O2.

The adsorption of arsenic from aqueous solution on synthetic zeolites H-MFI-24 (H24) and H-MFI-90 (H90) with MFI topology has been investigated at room temperature (r.t) applying batch equilibrium techniques. The influences of different sorption parameters such as contact time, solution pH, initial arsenic concentration and temperature were also studied thoroughly in order to optimize the reaction conditions. The adsorption of arsenic on to H24 and H90 follows the first-order kinetics and equilibrium time was about 100 min for both the adsorbents. The first-order rate constant ( k ), 4.7 × 10 −3 min −1 for H90 is more than two times higher in magnitude compared to 2.1 × 10 −3 min −1 for H24. Adsorption performance of H90 is higher compared to H24 due to it's highly mesoporous nature which in turn accelerates the diffusion process during adsorption. As(V) sorption capacity derived from Langmuir isotherm for H24 and H90 are 0.0358 and 0.0348 g g −1 , respectively. Arsenic uptake was also quantitatively evaluated using the Freundlich and Dubinin–Kaganer–Radushkevich (DKR) isotherm models. Ion exchange between adsorbent's terminal aluminol groups with different predominant forms of arsenate in solution is one of the various important reactions occurred during adsorption process.

due to the increased heat capacity. The higher the heat capacity of car-rier gas, the faster is the heating of TEMS and is the formation of the nuclei. The same effect was also expectedby the reduced flow rate of pure TEMS with larger flow rate of steam. Feeding the water from the lower partof the reactor avoided the instantaneous thermal decomposition of TEMS and accelerated its hydrolysis. Thegenerated particle diameter was also demonstrated to be affected by the reactor type. By suppressing the backmixing, the standard deviation of the produced fine SiO

The water pollution by harmful organic compounds is one of the most important environmental problems now. We focused on sonochemistry which is a method of decomposing and removing these pollutants. In this study, relationship between reaction rate of sonochemistry and operational parameters (sound pressure, initial concentration and hydrophilicity of organic compounds) was investigated. Reaction rate was found to be increased with increasing sound pressure. The decomposition rates of compounds were found to increase but their pseudo first order rate constants were found to decrease with their increasing initial concentration, which suggests around half order kinetics. Finally, their reaction rates were found to increase when the smaller the hydrophilicity of decomposed compound (the greater the hydrophobicity of compound) becomes.

Contamination of soil and ground water by trichloroethylene (TCE) has become a serious problem in recent times. Fenton reaction can be used for the chemical decomposition of polluting substances. In this study, Fenton reagent was used as an in situ oxidizing agent for soils contaminated with TCE. We investigated the kinetics of TCE decomposition by Fenton reaction involving Fe(II). The results of our experiments show that the rates of TCE decomposition in the presence of all soils except Toyoura sand are lower than that in the absence of soils. TCE decomposition by Fenton’s reaction with Fe(II) in the presence and absence of black soil was found to be of the first order to concentrations of TCE and Fe(II) and half-order to hydrogen peroxide concentration. The reaction rate constants in the presence and absence of black soil were determined to be 1.048 and 0.568 (L·mol–1)1.5·s–1, respectively. Assuming the reaction order to be 2.5, the reaction rate constants in the presence of humic acid, Kanuma soil, Toyoura sand, and akadama soil were determined to be 0.849, 0.725, 1.050, and 0.354 (L·mol–1)1.5·s–1, respectively. The decrease in the rate is speculated to be affected by both specific surface area and carbon content of the soil.

The biomass energy production by intensive cultivation is expected in future. In this study, we assumed large-scale plantation in an arid land of Western Australia. We analyzed inventory about conversion processes to various fuels from produced wood. Our evaluation indexes are calorific yield as fuel (energy in produced fuel per one ton dry-wood), CO2 emission (CO2 emission from fuel production process per one ton dry-wood) and external energy consumption per one ton wood (primary energy basis). Calorific yield as fuel was also evaluated for the independent case where all input energy was assumed to be supplied from biomass itself or fuel from it. From the results on energy consumption and CO2 emission analyses with external energy input, transportation of wood or fuel was found to be negligibly small in case that the conversion process was located in Australia. But in case that conversion process was located in Japan, that was considerably high (15-40%). From the independent scenario (without energy input except that from biomass itself) analysis, in case of conversion process in Australia and transportation of produced fuel to Japan, 34% of the energy in the whole wood (at the maximum condition of 50% in the feedstock except felling loss) was at the maximum, expected to be recovered as energy in fuel for methanol production case. More than 30% (up to 55%) of the energy in the wood was exhausted in the conversion process. Energy based yield of fuel and CO2 emission were much more influenced by the difference of target fuel or conversion process than the conditions of location and transportation.

A novel methacrylic monomer, 4-cyanophenyl methacrylate (CPM) was synthesized by reacting 4-cyanophenol dissolved in methyl ethyl ketone (MEK) with methacryloyl chloride in the presence of triethylamine as a catalyst. Copolymers of CPM with methyl methacrylate(MMA) at different composition was prepared by free radical solution polymerization at 70±1 °C using benzoyl peroxide as initiator. The copolymers were characterized by FT-IR, 1H-NMR and 13C-NMR spectroscopic techniques. The solubility of the polymers was tested in various polar and non polar solvents. The molecular weight and polydispersity indices of the copolymers were determined using gel permeation chromatography. The glass transition temperature of the copolymers increases with increase in mole fraction of MMA content. The thermal stability of the copolymer increases with increases in mole fraction of CPM content in the copolymer. The copolymer composition was determined by using 1H-NMR spectroscopy. The monomer reactivity ratios estimated by the application of linearization methods such as Fineman-Ross (r1=2.524±0.038, r2=0.502±0.015), Kelen-Tudos (r1=2.562±0.173, r2=0.487±0.005) and extended Kelen-Tudos methods (r1=2.735±0.128, r2=0.4915±0.007).

金沢大学理工研究域自然システム学系, Arid land afforestation could be a countermeasure for global warming, and a project for developing and evaluating techniques for arid land afforestation and reforestation has been carried out in Sturt Meadows near Leonora, Western Australia. As a part of this project, the litter carbon dynamics were investigated at three Acacia aneura forest sites, using a litter carbon model incorporating the physical removal of litter by winds, floods, etc. Based on the field observation data of above ground plant biomass, annual litter fall, existing amount of the litter, and also litter decomposition rate constants separately obtained for leaf litter and woody litter, we investigated the carbon flows at these forest sites, especially the annual amount of litter physically removed from the sites by floods or winds. As a result, it is estimated that annual physical removal of litter amounted to 59-75% of the annual litter fall, and the litter removal rate constants were from 0.38 to 0.55 year-1. Roughly one third to a half of the existing litter is removed annually from the sites. There was also a tendency that as the canopy coverage decreases, the litter removal rate constant increases. For this type of ecosystem, which is susceptible to the run-off of water and strong winds, we consider the taking into account of the physical removal of the litter is essential for analyzing the carbon dynamics in the ecosystem. © 2008 Elsevier B.V. All rights reserved.

TiO 2 /SiO 2 /Fe 3 O 4 composite was synthesized by sol–gel technique for silica and titania coatings on magnetite core to enable recovery after photocatalytic degradation. Carbon coating was also carried out by calcination of TiO 2 /SiO 2 /Fe 3 O 4 under nitrogen atmosphere in presence of PVA as a source of carbon to enhance the adsorption of organic compounds on catalyst surface and to get better activity. All prepared samples were characterized using EDX, CN analyzer, XRD, BET and SEM. Degradation of methyl orange dye was used to assess the photocatalytic performance of the prepared samples. Calcination temperature was found to affect rate of reaction because of the formation of rutile phase at high calcination temperature. Carbon coated samples unexpectedly exhibited lower rate of reaction at almost all calcination temperatures.

With a three-dimensional comprehensive computer simulation model, the effect of mixture fraction fluctuations on the overall gasification characteristics due to a turbulent flow was studied for gasification in oxygen blown HYCOL entrained-flow coal gasifiers. The method compared the results with or without fluctuation of the gas-mixture fraction. The theoretically predicted results were also compared with experimental data obtained from a 50 ton/day pilot-scale HYCOL gasifier. It was seen that the fluctuation in mixture fraction of gases produced from devolatilization is just as important as that of char-O2 reaction, i.e. neither of them can be neglected. They have an important influence not only on the temperature and gas composition distributions, but also on the cold gas efficiency and product gas composition. However, the fluctuations of gas-mixture fractions produced from char-CO2 and char-steam reactions have only a limited effect. This conclusion is valid for a wide range of conditions of pressure, particle size and O2 concentration during entrained-flow coal gasification. Based on these results, the simulation model can be simplified without significantly influencing the validity of the predicted results. The predictions that include fluctuations of mixture fractions show better agreement with the experimental data.

Selective permeation of vanadium(V) and chromium(VI) using three types of membrane systems was studied. The first was an anion exchange membrane, the second and third were supported liquid membranes containing either a tertiary amine or a quaternary ammonium salt. The membrane was sandwiched between two glass cells. One cell was filled with a solution of identical concentrations of vanadium(V) and chromium(VI), and the other cell contained sodium hydroxide solution. The permeation rates of vanadium(V) and chromium(VI) were measured from the concentration change in the solution on the recovery side of the membrane. The selectivity of vanadium(V) over chromium(VI) was defined as the ratio of their rates. The selectivity of vanadium(V) over chromium(VI) was as high as 10 for pH of feed phase between 8 and 10 when using the quaternary ammonium salt and much better than these for the other membranes with an alkaline feed phase, which was used to simulate of the effluent from leaching of the heavy oil combustion ash and other wastes containing vanadium.

The mechanism and effect of char on N2O formation and reduction during circulating fluidized bed coal combustion were examined in a bench-scale circulating fluidized bed. It was found that char derived from coal with high volatile matter content has a higher conversion ratio from char-N into N2O during char combustion. Furthermore, char with greater pore volume and specific surface area not only shows a higher conversion ratio from char-N into N2O, but also has stronger N2O reduction ability. Big pores play the main part in N2O diffusion inside char particles whereas small pores play the main part of chemical reaction. Molecular diffusion and Knudsen diffusion are both important for N2O diffusion in char. The reactivity of char concerning N2O formation and reduction is closely related to its pore characteristics, which is an important factor to account for the diverse N2O emissions from combustion of various coals in a circulating fluidized bed.

A commercial grade carbon black was chemically modified using mineral acids (either with HNO3 or H2SO4 or mixture) and the sorption performance of the virgin and modified forms were investigated. Chemical modification resulted in the creation of surface acidic functional groups (COOH, SO2OH) and was verified by FTIR spectra. This was further verified by TGA analysis revealing higher weight loss characteristics of the modified carbons in comparison to virgin carbon black. Morphological changes were observed from BET surface area measurements and SEM analysis. XRD study revealed the change of graphitic crystallite size as a result of modification. The suspension pH of the materials in deionized water and the point of zero charge (pHpzc) in inert electrolyte were determined. The measured values of suspension pH and pHpzc for all the carbons were found to be acidic with more acidic character in the modified carbons. These materials were used as sorbents for the removal of arsenic from aqueous medium and showed excellent adsorption performance.

Ozonolysis of triacylglycerol was carried out over heterogeneous catalysts. The triacylglycerol was decomposed to some compounds with low boiling points containing hydrocarbons, aldehydes, ketones, fatty acids and lactones over H-Y zeolite catalyst at 353-423 K. The amounts of products were strongly dependent on the properties of catalysts and reaction conditions.

This paper describes the preparation of several new transparent and very fine crystal glass-ceramics from the BaO-B2O3 system utilizing an appropriate additive of fluorides, partial replacement of B2O3 by SiO2, and introducing nucleating agents, such as TiO2. The physical properties of the prepared materials and the changes with varying base glass compositions and heat treatment programs were investigated. The thermal behavior and microstructure of the developed phases were characterized using DTA, XRD, and SEM. Glass-ceramics with marked transparency were prepared. These transparent derivatives owe their transparency to the distinctive properties of the nano-crystalline samples. The dielectric constant of transparent glass-ceramics samples at 100 kHZ were between 14-20, which is very suitable for a wide range of applications, such as the high-speed switching of large-scale integrators. It was found that the addition of F- and SiO2 greatly influenced the transparency of the produced glass-ceramics. Also, the addition of TiO2 greatly enhanced transparency, in spite of increasing cutoff in the UV region to a higher wavelength.

乾燥地における大規模植林による炭素固定のための技術確立が求められている．乾燥地に降る貴重な降雨を有効に利用するために，不透水層破壊による土壌構造改善技術の導入，および土盛りによる堰（Bank）を築いた西オーストラリア州レオノラ近郊を対象とした植林実証試験が行われている． 本研究では，集水技術導入による塩類の供給，蓄積の変化に焦点をあて，Bank内の土壌および雨水，表面流出水，灌水の化学性評価から，集水に伴う塩類集積状況の把握を行った． Bank造成および植林開始から5年経過時点では塩害発生には至っていないが，Bank外と比べ中では電気伝導度，水溶性イオン濃度共に高く，ゆっくりとではあるが蓄積していることが示唆された． また，元素ごとに供給源の水を特定した．Na，Ca，Mgは主に灌水より供給されており，灌水の供給を止めた現在以降は蓄積の恐れが無いと期待された．一方，植物必須元素であるK，Pは，主に雨水より供給されている．土壌の化学分析の結果からも根域での濃度が裸地部と比べ高く，リターや樹幹流による土壌への還元があると考えられる．