A water-activated battery based on activated carbon

In this research, a novel property of activated carbon powder (AC powder) has been utilized to realize a disposable paper-based battery. AC powder was loaded on a 3D carbon paper substrate to make the anode. The cathode was integrated directly on the paper-based battery case by coating multiwalled carbon nanotube mixed with potassium ferricyanide on a side of a sheet of filter paper, the other side worked as a paper-based proton exchange membrane. This design provides a simple but practical disposable water-activated battery. The developed battery generated the maximum power density of 10.4 µW/cm2 at the AC powder concentration of 17 mg/cm2. Although, the output power of the battery is low, it is made of low-cost and abundant materials, and therefore being able to scale up. The battery is a disposable and on-demand micropower generation activated anytime, anywhere by water

Enhancing DSSC conversion efficiency by ozone-treated TiO2 photoanode and optimum CNT/PDDA counter electrode

The conversion efficiency of dye-sensitized solar cells (DSSCs) depends on the performance of the photoanode and the counter electrode. In this paper, UV-ozone treatment has been applied to the photoanode to clean and increase the hydrophilicity of the photoanode. As a result, the dye adsorption capacity was improved. Also, low-cost multiwalled carbon nanotube (CNT) combined with poly (diallyl dimethylammonium chloride) (PDDA) was used to fabricate the counter electrode. The CNT/PDDA counter electrode was optimized to maximize its performance. By using the ozone-treated photoanode and optimum CNT/PDDA counter electrode, the conversion efficiency has increased by about 64%

ショウガ・プロテアーゼの精製と安定化(B. 生活科学)

ショウガの根に含まれる蛋白質加水分解酵素をアセトン処理, りん酸緩衝液抽出, CM-セルロースクロマトグラフィー, Bio-Gel P-100によるゲルクロマトグラフィーなどの処理により高純度に精製した.この際プロテアーゼの自己消化防止剤(安定化剤)として, HgCl_2とPCMBの水銀剤を使用しその効果を比較検討したが, HgCl_2を反応させScheme 1の方法で精製した酵素は, 二量体の酵素が生成していて, Bio-Gel P-100のクロマトグラム上で高分子の不純物と重り合った.PCMBで安定化した酵素をCM-セルロースクロマトグラフィーおよびBio-Gel P-100のゲルクロマトグラフィーにかけて得た標品は最も比活性も大きく純度の高いものであった.この標品は安定化剤を使用しないで精製し得られた標品の約6倍活性の強いものであった.またこの精製プロテアーゼのBio-Gel P-100による分子量の測定によると, 2万9千であって, この値はSDS-スラブ-ポリアクリルアミドゲル電気泳動によって求めた前回の実験値とよく一致した.Ginger protease which exists in the rhyzome (Zingiber officinale roscoe) was purified by chromatography on CM-cellulose and gel filtration on Bio-Gel P-100. In the course of the purification, HgCl_2 or p-chloromercuribenzoic acid (PCMB) was used as a stabilizing agent for the protease. It was shown that the protease stabilized with HgCl_2 formed a dimer complex which could not be separated from the higher molecular contaminant. The protease activity of the preparation stabilized with PCMB and purified by the chromatography was as high as 6-fold of that without PCMB. From the result of gel filtration on Bio-Gel P-100,the molecular weight of this purified protease was estimated to be about 29,000,which is the same as the value obtained previously by SDS slab-polyacrylamide gel electrophoresis

鶏卵 Flavoprotein のアガロースゲル(セファロース 4B)への固定化(B. 生活科学)

Immobilization of Egg White and Egg Yolk Flavoproteins on Agarose-gel Beads (Sepharose 4B) was tried by the CNBr activation method. The immobilized egg white flavoprotein had 63% of riboflavin-binding capacity of that of native flavoprotein, and the immobilized egg yolk flavoprotein had 74%. Both of the immobilized flavoproteins were resistant against a denaturing reagent, 2 M or 6 M urea. These immobilized apoproteins are useful as column packing materials for the determination of free and bound riboflavins in various materials and may be used for various purposes in laboratory or industrially owing to their stability

納豆菌の菌体外セルラーゼおよびキシラナーゼ(B. 生活科学)

納豆菌の菌体外セルラーゼを得るために各種液体培地で培養し, それらの滬液のCMCase活性を測定して検討した。その結果肉エキス, ペプトン, CMC, を含む培地で40℃2日間振盪培養すると最大の酵素活性を得ることができた。この酵素にはCMCaseだけでなくセルロース粉末分解活性も見られさらにキシラナーゼ活性がCMCase活性の約3倍も含まれることが明らかとなった。CMCase活性とキシラナーゼ活性とは今回は互いに分離することはできなかったがBio-Gel P-100によりそれぞれの比活性をかなり上昇させることができた。Cellulolytic activity was observed in the culture filtrate of Bacillus subtilis var. natto IFO 3335. The maximuin cellulolytic activity was obtained in the filtrate of two-days-cultured medium. This culture medium filtrate also contained an intense xylanase activity. The purification of these extracellular enzymes in the culture medium was tried by the gel chromatography of Bio-Gel P-100 and the specific activities of the enzymes was appreciably increased, although the isolation of the xylanase fraction from the cellulolytic activity fraction was not attained

塩蔵オキアミの利用に関する研究(第 1 報) : イソプロピルアルコール抽出法によるオキアミたん白質濃縮物 (KPC) およびエキスの調製(B. 生活科学)

An atempt was made to prepare the active krill protein concentrate (KPC) from salted antarctic krill by the extraction with isopropyl alcohol (iso-PrOH) without heat treatment. Salted krills were homogenized and filtered with Nylon gauze to remove the exoskeleton. Pink milky juice was mixed with an equal volume of iso-PrOH. As iso-PrOH does not miscible with salt solution, the miscella was separated into three layers by the centrifugation at 3,000rpm for 10min. The upper solvent layer contains lipids, pigments and other fat soluble vitamins. The krill protein was concentrated in the middle layer and non-protein nitrogen fraction, "the extractives", and the greater part of NaCl were recovered in the bottom aqueous layer. One of the typical KPC from salted krill contains 84% crude protein, 4% ash, 1% NaCl and 0.3% lipid and was rich in essential amino acids comparable to beef protein

食品中のビタミン U および酸加水分解による変化(B. 生活科学)

食品中,特に野菜中に含まれるビタミンUおよびメチオニンの定量分析を水抽出物および塩酸加水分解した試料について行った。分析した試料中では,塩酸加水分解試料中に含まれるメチオニンの量が他のメチオニン誘導体より多く,次いで水抽出物中のビタミンUであった。このビタミンUの分解産物はアミノ酸分析チャート上で他のアミノ酸ピークと合わさり,定量を妨害することがわかった。そこで標準のビタミンUを用いて,数種の塩酸加水分解処理操作を行い,モデル実験を行った。その結果通常の塩酸加水分解処理により,ビタミンUは約40%が壊されずに残り,約40%はメチオニンを生成することが明らかとなった。この他にホモセリンラクトン,ホモセリン等が生成することも明らかとなった。Analyses of vitamin U and methionine in water-extracts and HCl-hydrolysates of vegetables were carried out by cation-exchange high performance liquid chromatography. The water-extracts of the brassica vegetables contained much vitamin U than methionine, though the same vegetable samples hydrolyzed with HCl contained much more methionine than vitamin U. To elucidate the decomposition of vitamin U during the HCl-hydrolyses, standard vitamin U were treated in some HCl-hydrolysis conditions as a model experiment. About 40% of vitamin U were remained and several methionine derivatives were obtained after the HCl-hydrolysis

塩蔵オキアミの利用に関する研究(第 4 報) : アスタキサンチン(B. 生活科学)

The carotenoid, which extracted with isopropanol from salted antarctic krill (Euphausia superba) was identified as astaxanthin in ester form, and its content in the krill lipids was 0.128%. There is no significant deterioration of the pigment during the salted storage at -20℃ for 5 years. Astaxanthin in ethanol solution after acetone treatment of IPA extractives was more stable than that of other solvent treatment. The stability of the pigment was improved by the saponification of astaxanthin preparation, however, ethanol solution of purified astaxanthin with silicic acid column chromatography was very unstable. We suggested that the reason of unstability of purified astaxanthin might be the result of the elimination of naturally occuring antioxidant during the purification processes