Kimitoshi Horaguchi

Potential Use of Mercury-Free Lamps in Plant Factories

Abstract We investigated the effects on plant growth of a mercury-free lamp with high CRI, operated on inductive ballast. This lamp has a spectral power distribution in the 600 to 780-nm region, higher than that of conventional lamps. Since this lamp is free of mercury, it is less harmful to the environment than lamps that contain mercury; therefore, we believed that this type of lamp would be useful in plant factories. We examined the effects of the mercury-free lamp on the growth characteristics of sunflower and lettuce plants, and compared them to plants grown under conventional lamps. We concluded that the mercury-free lamp advanced plant growth, increased leaf area, and inhibited leaf number compared to the conventional lamp, making it attractive for large-scale use in plant factories.

Efficient Culture Method of Pavlova Lutheri by Light Intensity Control

Abstract Using artificial lighting, productive cost is high, and reducing the cost is an important factor of cultivation. To reduce productive costs, an economical method of culturing micro-alga, Pavlova lutheri using light intensity control was considered. Minimum light supply to grow cell was calculated using the growth curve at 10,30,60 and 100% light intensity. When light intensity control was simulated, consumption energy of light was reduced about 40% of 100% light intensity. In The actual growth using light intensity control, consumption energy was reduced about 60% of 100%light intensity.

Consideration of Influence of Lighting and Photographic Flash Lights on Color Deterioration of Exhibited Objects

生活水準の向上 とともに,よ り充実 した生活へのアプ ローチの方法 の一つ として,地 域に密着 した国公立の美 術館 ・博物館 などの文化施設が各地に建設 されている. また個人の所蔵家の収集品 も単に保有す るのでな く,一 般に公開展示 され る機運が増 している.こ れ らは美術館, 博物館のみならず,都 会地のデパー トな どでは有名 な美 術品 を中心 とした展示が企画 され,多 くの観覧者の人気 を集めている.多 くの観覧者を集め るような美術品は, 現在のわれわれが展示 し鑑賞す る機会 を持 つ とともに, 貴重な民族の文化遺産 として将来の人々に対 して保 存維 持す る必要があるこ とは言うまでもない. この ような企画展示が多 くなると,有 名 な展示品が出 品されない展示会 は成立 しづ ら くなる.こ れ を避け るた め美術館が相互に協調 して高名な作者の作 品の貸 し借 り が行 われている.他 の美術 館か らの借 り入れ美術品につ いては,展 示品の保護に細心の注意を払 うこ とになる. 一般 に農示会場や店舗では ,写 真撮影 は禁止されてい る.こ れは展示 品の著作権 の保護 という立場 と,フ ラッ シュ光撮影 による展示品の損傷 ・変退色防止の 目的が あ る.こ こではフラッシュ光 を含めた光放射 による展示 品 の保護 と展示照明について考えてみたい.

Characteristics of Marine Microalgae as a Result of the Change in Light Quality During the Culture Period

Abstract The recent scarcity of several marine stocks in Japan is a serious problem. Aquaculture has been increasing, but requires large amounts of marine microalgae as a food source. Therefore, this study was aimed at developing a system to mass-produce the microalgae Pavlova , using artificial light sources. Pavlova cells were grown under white, red, green, and blue fluorescent lamps. The highest cell density was obtained after 8-9 days of culture under white fluorescent lamps. The highest rate of oxygen generation by Pavlova cells was found at photosynthetic photon flux densities (PPFD) of 300 to 500 µmol m -2 s -1 in cultures grown under the white fluorescent lamps. Pavlova cells cultured under other cotored fluorescent lamps generated maximal oxygen rates at PPFD around 150 µmol m -2 s -1 .

Experimental Studies of the Relation between Light Intensity and Cell Density of Mass Cultured Pavlova lutheir.

Producing large quantities of microalgae is one of the most limiting factors when developing large-scale culture techniques for shellfish. When artificial light is used for producing microalgae, it is one of the most expensive costs. In this study, we conducted experiments to determine the optimum light intensity and efficient culture protocol for microalga Pavlova lutheri using a 200-liter chamber.A 200-liter culture chamber was used to determine the average distribution of PPFD. Under two conditions : 1) filtered seawater (control), and2) filtered seawater with culture medium added and 1.0×107 cells·ml-1 P. luatheri. Average distribution of PPFD for the filtered sea water was 1, 800μmol·m-2·s-1 at irradiation of the full light intensity. But when P. lutheri was cultured in the chamber, available photosynthetic area was reduced to a half of the chamber.P. lutheri was cultured at irradiation of10%, 30%, 60%and full light intensity at 15°C and an aeration of 30l·min-1. Maximum cell density correlated positively to light intensity with full light regime supporting more than 2.0·107cells·ml-1.We conclude that if higher light intensity is used for the chamber, P. lutheri will obtain nigher cell densities. Additionally the control of light intensity is effective method to decrease the production cost of P. lutheri.