"まぐろ延縄揚縄中,幹縄にかかる張力の計測記録について" / "/"狩俣, 忠男/""狩俣, 忠男 ,  "/今井, 健彦"(1000020041709)/"今井, 健彦"

鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University , 16 , pp.93 - 99 , 鹿児島大学

   鹿児島大学リポジトリ  鹿児島大学

概要

"During the execution of the tuna long-line haulin...

"During the execution of the tuna long-line hauling the main-line-tensions were recorded onthe paper of an Ink Writing Oscillograph by means of the Load Cell (type-LT) and the StationIndicator (type-SL7-L) installed for their measurement.The recorded tensions are as shown in Fig.2.The cause of the fluctuations in the records were assumed to be due to the following four factors:the mechanical conditions of the measuring equipment and the line-hauler; the operative state ofthe line-hauler; the oprative faculty of the long-line gears; the seamanship under the haulingoperation; and others.Thus, conversely, minute analyses of the tension-records were deeped to be available for theelucidation not only of the main-line tensions but of the issues concerning the working of theline-hauler, the operation of the gears and the seamanship in hauling the line.Now, as far as the analysis of the tension-records is concerned, no detection of any shockingtensions attributable to the pitching and rolling of the vessels and to the abrupt commencementof the long-line-hauling was made on the main-line."

"まぐろ延縄漁業の天然餌料に関する研究I : サンマ, ムロアジ, ホンサバ, スルメイカを用いた釣獲比較試験" / "/"今井, 健彦"(1000020041709)/""今井, 健彦"

鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University , 21 ( 1 )  , pp.45 - 50 , 鹿児島大学

   鹿児島大学リポジトリ  鹿児島大学

概要

"These experiments were carried out during the ter...

"These experiments were carried out during the term from 31st of May to 19th of June in 1970 on the western part of the South Pacific Ocean, on board the fishing training-ship “Kagoshima Maru” (G.T. 1,038 tons) belonging to the Faculty of Fisheries, Kagoshima University : experimental frequency being 8 times ; used gears 200 baskets of long-line，in each experiments ; used baits, four kinds of frozen baits of saury, round scad, mackerel and squid, each of which was attached, in this order, on to the hook of the respective basket of long-line. The results obtained are as in the following : 1. In case of the tuna-fishing, the hooking rates of saury and round scad showed the comparatively high rates of 2.95% and 2.51% respectively, while those of squid and mackerel showed the comparatively low rates of 1.19% and 0.95% respectively. In case of marlin and sword fish, the hooking rate of round scad showed a comparatively high rate of 0.84%, while those saury, mackerel and squid showed the comparatively low rate of 0.35%, 0.3% and 0.07% respectively. 2. Concerning the average hooking rate of each kind of bait in the total covering the two sorts of fish tuna, marlin and sword fish ; round scad showed the highest rate of 3.35%, which was followed by the saury rate of 3.30% ; both mackerel and squid showing the comparatively low rates of 1.27% and 1.26% respectively."

"まぐろ延縄漁業の天然餌料に関する研究II : サンマ, ムロアジ, ホンサバを用いた釣獲比較試験" / "/"今井, 健彦(1000020041709)/""今井, 健彦 ,  "/白川, 修"/"白川, 修"

鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University , 21 ( 1 )  , pp.51 - 62 , 鹿児島大学

   鹿児島大学リポジトリ  鹿児島大学

概要

"Following the results reported in the 1st paper, ...

"Following the results reported in the 1st paper, the same experiments were carried out during the term from 23rd of May to 14th of June 1971, mostly on the Coral Seaon board the fishing training-ship “Kagoshima Maru”. The results obtained are as follows : 1. In case of the tuna-fishing, the hooking rate of round scad showed the highest rate of 5.38% : those of saury and mackerel being 4.76% and 3.04% respectively. In case of marlin and sword fish, the hooking rate of mackerel sowed a comparatively high rate of 0.65%, those of round scad and saury being 0.32% and 0.11%, respectively. 2. Concering the average hooking rate in the total covering the two sorts of fish, tuna and marlin ; round scad showed the highest rate of 5.70%, which was superior to that of 4.86% showed by saury. 3. As to the dropping rate of the bait, saury showed the highest rate of 68.9% ; one of the dropping-causes was ascertained to by due to the fact that the bait was hooked un-melted. 4. These hooking rates are assumed to be influenced by some differences in the motions, in the flowing water, of these three kinds of baits, saury, round scad and mackerel. 5. In short, the possibility of using the frozen round scad for a bait of tuna-long-line was ascertained in these experiments."

網地剛体模型近傍の流速分布 / "/"今井, 健彦(1000020041709)/""今井, 健彦 ,  "/石崎, 宗周(1000090244269)/"石崎, 宗周 ,  "/不破, 茂/"不破, 茂 ,  "/久津輪, 修一/"久津輪, 修一 ,  "/金, 碩鍾/"金, 碩鍾 ,  "/洪, 性完"/"洪, 性完"

鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University , 43 ( 1 )  , pp.1 - 9 , 鹿児島大学

   鹿児島大学リポジトリ  鹿児島大学

概要

"This paper deals with flow-profiles around an enl...

"This paper deals with flow-profiles around an enlarged solid model of netting which was set into an experimental flume tank on every half angle of Θ, (range from 0 to 3Θ of setting angles), to clarify flow distribution around the model. In this case Θ means the angle of attack when mesh-hall faded out from the projective plane. A thin film flow-meter with corn shaped probe was used in the experiment. Measurements were carried out on 110 fixed points, 24 points around mesh, and 5 points inside mesh-halls at every attack angles on a horizontal plane. The flow-speed was maintained at 10 cm/s, and Reynolds number at 1.9×10^3. From the resultant profiles, the fluid-dynamical force acting on each leg was similar with the case larger than 3Θ of attack angles."

円錐網の抗力係数とレイノルズ数 / "/"洪, 性完/""洪, 性完 ,  "/今井, 健彦"(1000020041709)/"今井, 健彦"

鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University , 45 , pp.29 - 35 , 鹿児島大学

   鹿児島大学リポジトリ  鹿児島大学

概要

"A fluid dynamic of midwater trawl and codend are ...

"A fluid dynamic of midwater trawl and codend are associated with a flow velocity inside the net. This study investigates the relationship between drag coefficient of conical nets and Reynolds number which concerns with a flow velocity inside the net. In order to measure the drag of conical nets, twenty models of different open area ratios, which composed five kinds of twisted knotless nettings and four kinds of hanging angles, were tested in the flume tank of Kagoshima University. The mouth of each net was attached to a circular shaped frame to maintain geometric feature, and the nets were set into the flume tank normal to the flow direction. The velocity was monitored by a supersonic digital current meter which is installed in the flume tank, and the drag was measured using a three-component load cell. Measured values were stored in a data file of a computer for analysis. If uniform hanging angle is the significant factor affecting the drag of the conical nets depended on the open area ratio. When the representative velocity U_m/ β and representative length d were used as a characteristic velocity inside the net. And scale, a more general correlation between the drag coefficient and the Reynolds number are found using the exponential linear regression. C_D' was found to be C_D'= 18.88 Re'^<-0.63>."

円錐網の周りの流速分布 / "/"洪, 性完/""洪, 性完 ,  "/今井, 健彦"(1000020041709)/"今井, 健彦"

鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University , 45 , pp.21 - 28 , 鹿児島大学

   鹿児島大学リポジトリ  鹿児島大学

概要

"This paper deals with the velocity around the con...

"This paper deals with the velocity around the conical net in the flume tank at the Faculty of Fisheries, Kagoshima University. Eight types of conical nets were used for the experiment ; out of which four kinds were the same netting with different hanging angles, and the other four were the same hanging ratio with different nettings. The mouth of each net was attached to a circular shaped frame of the same dimension, and the test speed was 80 cm/s at a steady flow. The flow velocity in the test sections were measured with a hot film flow meter. The following results were obtained : 1) The velocity around the nets can be classified into 3 fields, inside net, in the boundary layer in which the flow is passed through a mesh hall and outside net. As the open area ratio (β) became smaller, the velocity of inside net increased but the velocity of boundary layer decreased. 2) The shape of conical net in a flow field depended on the mesh number rather than to the open area ratio of mesh. 3) The theoretical analysis was carried out on the continuity equation to derive an empirical equation for the average flow velocity on the cone type nets."

オッターボードの研究 : 多翼型オッターボードの性能について / "/"今井, 健彦(1000020041709)/""今井, 健彦 ,  "/小山, 重美"/"小山, 重美"

鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University , 24 , pp.87 - 97 , 鹿児島大学

   鹿児島大学リポジトリ  鹿児島大学

概要

"Studies on midwater otter boards which are mainly...

"Studies on midwater otter boards which are mainly composed of Wing board (Larsson’s Phantom trawl), Dualfin board (British Columbian trawl), Hydrofoil otter board (Süberkrüb) and Bie-plane otter board (Kobayashi), are comparatively recent development. This paper deals with the performance of multi-plane otter board, whose structure is similar to that of a paravane-shearing-board. The model experiments were carried out on sea and at circular tank. The model was made with galvanized iron-plate (0.48 mm in thickness), dimension of the model being 23.4 cm in length, 21.7 cm in width, and 225 g in weight, respectively. The results obtained are as follows; 1．The critical attack angle of the multi-plane otter board was determined to be 25.5 degrees. 2．Through the results of fig. 6 the relationship between lift-force and towing-speed, and, between drag-force and towing speed may be expressed in the following empirical formulas. L=42.7V^{1.99}. D=34.4V^{2.05}. 3. The ratio of lift and drag in the multi-plane otter board was ascertained to be 1.28, which shows the intermediate value between the upright type otter board (C_L/C_D=1.85), and the ordinary one (C_L/C_D=0.8)."

夏季東支那海南部のホンサバについての知見(予報) / "/"今井, 健彦"(1000020041709)/""今井, 健彦"

鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University , 16 , pp.76 - 84 , 鹿児島大学

   鹿児島大学リポジトリ  鹿児島大学

概要

"Some investigations on the habitat of the common ...

"Some investigations on the habitat of the common japanese mackerel were carried out by the ""Kagoshima Maru"", training ship of the Faculty of Fisheries, Kagoshima University, in the southernwaters of the East China Sea in summer, both in 1964 and in 1965. The results are obtained asfollows:1) It was in the sea-front situated at the cross-section, lat. 29°-30' N and long. 124°-00' Eand its vicinity that the confirmed catch of the common japanese mackerels including that of otherfishes was carried out with the trawl-net in June and August, 1964.2) The fork length of the common japanese mackerel caught there, was ranged in 280~350mm.3) It was ascertained that, in the littoral water mass, water temperature 17~22°C and salinity34.0~34.5‰ in summer, the habitats of some schools of the common japanese mackerels were tobe found at the water near the bottom."
"1. 夏季に東支那海南部海域に棲息しているホンサバとその漁場環境について調査した。2. 北緯29°-30',東経124°周辺の水深70mの海域で6月と8月にトロール網で漁獲された魚類の中にホンサバが混獲された。3. ホンサバの体長範囲は280~350mmであった。4. ホンサバは夏季大陸沿岸性の水塊中で水温17~22°C,塩分34.0~34.5‰の範囲の底層近くに棲息しているものと推定される。"

かご漁具の形状と漁獲機構 / "/"不破, 茂/""不破, 茂 ,  "/川野, 和昭/"川野, 和昭 ,  "/杉本, 裕司/"杉本, 裕司 ,  "/石崎, 宗周(1000090244269)/"石崎, 宗周 ,  "/今井, 健彦"(1000020041709)/"今井, 健彦"

鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University , 46 , pp.21 - 30 , 鹿児島大学

   鹿児島大学リポジトリ  鹿児島大学

概要

"Various shapes of entrance in basket traps were u...

"Various shapes of entrance in basket traps were used in rivers of southern Kyushu and their fishing mechanisms were studied. Dimensions of basket traps were measured and their physical characteristics were examined. The external shapes of entrance were divided into two categories by current conditions at the area where basket traps were used. The basket traps in deep rivers have a square shape with a short, large angled throat. Two types of basket traps were used in shallow rivers ; one has a cylinder shape with a long, small angle throat, and the other has no throat. The angle of entrance without throat was inclined. The curved shape of entrance seemed to guide fishes into the basket trap and to hold them inside. The inclined angle of entrance for shrimp was smaller than that for fish. It may be assumed that the shapes and angles of entrance in basket traps could be affected by current conditions in and around the traps as well as by swimming behaviours of the target fish."

鹿児島市沖合に設置された人工魚礁 / "/"不破, 茂/""不破, 茂 ,  "/今井, 健彦(1000020041709)/"今井, 健彦 ,  "/田畑, 静夫/"田畑, 静夫 ,  "/金, 碩鍾/"金, 碩鍾 ,  "/久津輪, 修一/"久津輪, 修一 ,  "/熊澤, 泰生"/"熊澤, 泰生"

鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University , 40 , pp.111 - 121 , 鹿児島大学

   鹿児島大学リポジトリ  鹿児島大学

概要

"The fish gathering effect and setting condition o...

"The fish gathering effect and setting condition of the artificial reefs were studied on the basis of field experiments off Kagoshima City. Three types of artificial reefs: one concrete block reef, two bus reefs and one lava reef were surveyed by scuba diving. Field results were analyzed with respect to the fish fauna and dispersion of reef after setting on the sea bottom. The results are as follows. Bus reef showed the highest fish gathering effect. However, poor fish fauna was found at the reefs north of west Sakurashima pass as compared to the others. The distribution of the reefs differed from the scheduled arrangment. The difference seemed to be caused by the errors at setting due to movement of marker buoy and inaccuracy of positioning of the ship. These suggest that setting operation should also be considered in order to increase the accurarcy of reef arrangment."