Nanostructured zinc oxide (ZnO) is a versatile material with a wide range of applications ranging from nutrition to light-emitting devices, and doping of ZnO with calcium (Ca) may improve its performance. However, there is only a limited understanding of the crystalline properties of nanostructured CaO-ZnO systems. Here, nanostructured Ca-doped ZnO was produced by flame spray pyrolysis and characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). No Ca-Zn oxide phase with specific stoichiometry was formed, but an increase in the ZnO unit cell parameters was observed with increased Ca content. Using Vegard’s law, approximately 2.8 at% Ca was incorporated substitutionally for Zn in nano-ZnO, in agreement with solubility limits reported for bulk ZnO. These results indicate that there is no specific particle size effect for the formation of CaOZnO solid solutions. This Ca incorporation inside the ZnO wurtzite structure resulted in a transformation from slightly elongated to more spherical crystals, as indicated by the ZnO aspect ratio and TEM images.

本研究では，ペレット状ゼオライトに吸着したメチレンブルー（MB）を誘電体バリア放電（DBD）で分解し，ゼオライトを吸着剤として再利用した。DBD処理は，大気圧下の空気中で実行された。プラズマ処理がゼオライト構造に及ぼす効果を調査した。DBD処理の効果は，繰り返し吸着テストでゼオライトに吸着されたMBの量と溶液の全有機体炭素（TOC）によって評価された。プラズマ処理したゼオライトを純水に加えると，ゼオライトからいくつかの物質が脱離した。NMR分析の結果，その物質はベンゼン環構造を持たないことが示された。その結果，ゼオライトに吸着したメチレンブルーはDBD処理によりベンゼン環のない低分子に分解され，次の吸着サイクルで脱着し，ゼオライトの構造を維持したまま吸着部位が回復したことが明らかになった。

国内にある石炭火力発電所から採取した石炭灰フライアッシュに関して，６種類のペーパースラッジ燃焼灰（以下，PS灰：XA，XB，XC，YA，YB，YC）を溶出抑制剤として添加した際の異なるPS 灰添加率（0-30%）に対するヒ素（As）溶出挙動を調べた。さらに，ヒ素溶出メカニズムを解明するために，先に得られた実験結果に基づいて熱力学平衡計算ソフトウェア Fact Sage 7.2を用いてフライアッシュ中におけるAs含有化合物の推定と燃焼および溶出プロセスにおけるAs 含有化合物分布予測を行い，種々のパラメータ（温度，PS 灰添加率，微量元素濃度など）がヒ素溶出挙動の熱力学平衡解析に与える影響を評価した。結果として，燃焼プロセスにおいて生成されるAlAsO₄(s) がフライアッシュ中に含まれる主なヒ素化合物であることが平衡解析により示された。また，PS 灰YBを添加率15-30%にてフライアッシュへ添加することで最も良いヒ素溶出抑制挙動を確認した。これはPS灰添加量が増えたことで溶出過程におけるカルシウム（Ca）量が増えた結果，Ca化合物Asとの化学反応が促進されたことにより，As固定量が増大したことに起因する。また，PS灰中に含まれるCaOにより溶出液pHが高まり，カルシウムとヒ素の反応を促し，沈殿物を形成することも明らかになった。

A new activation method using a pseudo continuous reactor with microwave-induced plasma is examined to prepare activated carbon. Carbonized carbon gel is mixed with potassium hydroxide before being activated by microwave irradiation. The specific surface area of the product is investigated by varying microwave-retention time. The results show that the activated carbon with specific surface area of 3,054 m² g^-1 and total pore volume of 1.35 cm³ g^-1 can be obtained within 510 s, although hour-level time is necessary to obtain similar activated carbon if conventional methods are used. Temperature change of the carbon precursor caused by microwave irradiation was measured in batch mode to estimate the temperature at pseudo continuous system based on the retention time. It was found that the retention time to reach 700 °C of the carbon precursor can be essential factor to achieve high surface area and large pore volume. In addition, the activated carbon synthesized by the proposed method can show an average mass yield percentage of 24.2%, which is much higher than that from conventional methods, 4.5-5.0%. Based on the influence of the microwave retention time, reaction mechanism is discussed. The fast rate and high yield shown here should contribute to energy-saving process.

本研究では，燃料電池及び水素吸蔵合金カートリッジを搭載したアシスト自転車（H-bike）を用いたコミュニティサイクル（シェアサイクル）の導入に関し，次の２つの課題を検討した。1つ目は，発進・停止回数及び走行距離に起因する電力需要の課題，また２つ目は，従来のLi-ion電池自転車（E-bike）との比較時に生じる水素吸蔵合金カートリッジ利用による重量増加の課題である。これらの課題は，一般的にはアシスト自転車の性能低下に影響を及ぼすと推察されるが，本研究では自転車タイヤの空気圧を上昇させ，転がり抵抗を低下させることでその影響を低減できることを，実験的に確認した。車体荷重の増加，停止回数の増加及び移動距離の増加に対する，転がり抵抗の影響を評価し，電力需要が低減されること，また水素吸蔵合金カートリッジによる重量増加の影響を無視できることを示唆した。重荷なし，停止回数10回，約2 km走行の条件下において，タイヤの空気圧を2.00 kg/cm²から3.00 kg/cm²に増加させることで，消費電力量が15%以上削減されることが示され，停止回数が多く，走行距離が長いシェアサイクル環境下では，タイヤ圧上昇の効果が大きいことが分かった。また本研究では，バイオ水素の利用を１つの方策として掲げており，LCA手法を用いた環境影響評価を実施した。その結果，CMLモデルの影響領域である非生物資源枯渇性（ADP）と地球温暖化（GWP）について，それぞれE-bikeと比較して約10%，及び20%低い値を示した。

Coconut jelly, the solid waste from ready-to-drink industry, was used to produce solid fuel pellets. Pelletization was done by a single 10-ton hydraulic press unit without any binders. The characteristics of the pelletized fuel including pellet dimensions, bulk density, pellet density, proximate analysis, higher heating value, energy density, combustion rate, heat release rate, compressive strength and durability were investigated. The pellets had an average diameter and length of 10 mm. Pelletization significantly increased the bulk density from 30 kg/m³ of the original coconut jelly and 70 kg/m³ of ground dried coconut jelly to 659 kg/m³ of the pellets. Proximate analysis values of pellets (moisture 8.05 wt%, ash 2.06 wt%, volatile matter 77.04 wt% and fixed carbon 12.85 wt%) indicated good combustion parameters. The higher heating value of the pellets was 15.995 MJ/kg, which increased by 19.05% from its original form. The pellet density was 1,100 kg/m³ and the resulting energy density was 17.59 GJ/m³. The fuel pellets also increased the combustion rate and heat release rate from 0.05 to 0.17 g/min and 672 to 2,719 J/min, respectively, when compared with the original form. The pellets had a high durability (98 wt%) and high compressive strength in horizontal direction (4.84 MPa). Overall, the properties of coconut jelly pellets meet the requirements of Thai and European standards of the pellet properties for non-woody materials. Thus, coconut jelly waste could be considered as a potential raw material to manufacture pellets as an alternative energy source.

微細藻類とりわけユーグレナによる有用物質生産の実用化が期待されている。微細藻類の生産性を高める上で，増殖促進剤の添加は，簡便かつ費用対効果の高い方策である。本研究では，リグニンを原料として得られる芳香族化合物バニリンの効果について検討を行った。ユーグレナの培養に対するバニリンの添加はホルミシス効果，すなわち低濃度では増殖促進したが，高濃度では増殖阻害をおこした。10 mg/Lのバニリン添加区において，バイオマス生産性が36.5％向上し，クロロフィルやカロテノイドの含有量も上昇した。さらに，バイオマス生産性を損ねることなく，脂質の収率を高めることが可能であることを，FT-IRを用いて確認した。

The novel and facile multi-stage method was used for the preparation of nanocellulose from cassava bagasse in Vietnam. Firstly, the cassava bagasse was treated with sodium hydroxide solution followed by chlorine dioxide bleaching for obtaining cellulose pulp with a brightness of 82% ISO. Secondly, the obtained bleached cellulosic pulp was achieved with a dilute sulfuric acid and hydrogen peroxide followed by purification and refining for obtaining nanocellulose. The following optimal conditions of the acidic treatment with adding of hydrogen peroxide for isolation of nanocellulose were proposed: concentration of hydrogen peroxide 0.1 wt.%, the concentration of sulfuric acid 0.25 wt. %, liquor to cellulose ratio 20 to 1, temperature 110 °C, time 100 min. The characteristics of nanocellulose were studied by SEM, FTIR, and XRD.

In this communication, the zinc anode electrode was prepared by electroplating. MnO₂ cathodes and Ni(OH)₂ cathode electrodes were prepared by the pressing process. KOH 6 M with 40%ZnO were used as the electrolyte solution of a battery. X-ray diffraction (XRD) was used to study the complexation of cathode electrodes. The Fourier transform infrared spectroscopy (FTIR) analysis showed some peaks which ascertain chemical interlinking of ZnMnO₂ and Zn-Ni(OH)₂ on cathode electrodes. After performance testing, morphology characterization of zinc anode electrode was performed by scanning electron microscopy (SEM). The electrodes were tested for performance by a battery analyzer for 100 cycles with a depth of discharge (DOD) at 10%, 20%, 40%, and 80%. It was found that zinc electrodes had branching of a dendrite, which quickly grew at a high depth of discharge. The depth of discharge influenced dendrite growth and the battery performance during cell discharging at high DOD. The Zn anode was damaged due to the excessive dissolution of Zn⁺ in the electrolyte, causing the decay of the Zn anode. On the other hand, during cell charging, Zn⁺ was not uniformly deposited on the anode, resulting in dendrite branching. Zinc electrode in Zn-MnO₂ cell had more dendrite than zinc electrode in Zn-Ni(OH)₂ cell at 10%DOD. The results also showed higher efficiency of 99.08% and better stability for Zn-Ni(OH)₂ than Zn-MnO₂ cells in similar conditions. This was due to the fact that during cell discharge. Mn⁺ in the electrolyte continuously reacts with Zn⁺ to form other complex compounds. On the contrary, Ni(OH)₂ cathode exhibited better recyclability than MnO2 cathode. Therefore, Ni(OH)₂ cathode offers excellent potential for use as a cathode electrode because it can be used at high DOD. Another advantage of Ni(OH)₂ cathode is that it can be prepared from a simple process by making use of readily available non-toxic materials.

This work aims to study biofuel production from rice bran oil (RBO) using a hydrocracking reaction over 0.5%Pd/Al 2O3 catalyst. The Central Composite Design (CCD) was used to find optimal bio-hydrogenated gasoline (BHG) production conditions. The effects of pressure and temperature, including the interaction of the parameters under the constant liquid hourly space velocity (LHSV), were determined by the statistical methodology of surface response (RSM). The yields of liquid biofuel products and BHG, as well as BHG selectivity, were used as response values for optimizing BHG production. The results remarkably showed that pressure and temperature significantly influenced BHG production in terms of yield and selectivity. The optimal condition for BHG production was found to be at 516 °C and 4.8 MPa, with the BHG yield of 44.21%. However, the optimal BHG selectivity was found to be at 532 °C and 4.4 MPa with a selectivity of 69.74%. Moreover, temperature appeared to be a more dominant parameter on biofuel product yield than the pressure. This parameter had greater effects on both linear and square terms in ANOVA analysis of the biofuel product yield. Furthermore, hydrocracking was discovered to improve the heat of combustion of BHG as compared with the initial feedstock and commercial gasoline. The total acid value of BHG was also found to increase because the reaction could break the ester bond between glycerol and carboxyl groups; thus, free fatty acids were formed, causing the high value of total acid in the sample.

常設編集委員会に加え，次の方々にゲストエディタとしてご協力いただいた。 井上修平（広島大学），澤山茂樹（京都大学），野村信福（愛媛大学），難波慎一（広島大学）