巻号一覧
14 巻 (1958 - 1959)
- 4 号 p. 121-
- 3 号 p. 81-
- 2 号 p. 41-
- 1 号 p. 1-
14 巻, 2 号
選択された号の論文の9件中1～9を表示しています
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(1) 陽炎の中の乱流輸送現象井上 栄一1958 年 14 巻 2 号 p. 41-44
発行日: 1958/10/31
公開日: 2010/02/25
ジャーナル フリーRecent developments by Monin-Obukhov (1954) and Priestley (1957) in the study of natural convective phenomena near a heated surface have been made use of to obtain the turbulent transport flux equation applicable to phenomena under the extremely weak wind conditions in the hot daytime, in which the ordinary aerodynamic method of estimating the turbulent transport flux can not be applied. The “-1/3 power law” for the vertical temperature distribution and the “-4/3 power law” for the vertical temperature gradient distribution have been examined with the observations made by us and by Ramdas (1953). These laws give an expression of the turbulent transfer coefficient K as follows:
K=HC*(g/Θ0)1/2|dΘ/dZ|1/2Z2,
where HC* is the Priestley's (1957) constant of the value of about unity. The value of K can be calculated by observing the air temperature distribution and the transport flux is thus calculated as the product of K and the gradient of physical quantities concerned. Making use of the data given by Ramdas (1953) some estimations of K and q, the heat flux, have been carried out.抄録全体を表示PDF形式でダウンロード (580K) -
井上 栄一, 谷 信輝, 今井 和彦, 礒部 誠之1958 年 14 巻 2 号 p. 45-53
発行日: 1958/10/31
公開日: 2010/02/25
ジャーナル フリーThe aerodynamic method of measuring the rate of photosynthesis over the cultivated fields, which makes use of the equation of turbulent transfer such as
P=(U2-U1)(C1-C2)/33.1(logZ2-d/Z1-d)2
and has been applied successfully to the unlimitedly wide fields, is to be applied with much care to the narrow fields of limited dimension such as a nursery of rice plants. The reasonable heights of Z1 and Z2 where the velocities U1 and U2 and the concentrations C1 and C2 are to be obtained are examined taking both the height of plants and the windward length of the field concerned into account simultaneously, and also taking account of the thermal stability of the air layer. Alternative two methods of some possibilities are presented. One is the fluctuation method making use of the mean product of the vertical components of wind velocity fluctuations and the CO2 concentration fluctuations, and the other is the traverse method which makes use of the vertical integration of the horizontally flowing CO2 flux.
The aerodynamic method has been applied practically to a nursery of rice plants 20cm high of limited scales with much caution in order to avoid meeting anticipated difficulties. The profiles of U, C, Θ (air temperature) and E (humidity) over the nursery have been obtained during almost a whole day in June 1957. The net radiation flux has been obtained simultaneously by means of a Beckman-Whitley net-radiometer. The assimilation type of C-profile in daytime characterized by increasing CO2 concentration with height and the respiration type in nighttime characterized by decreasing concentration with height have been obtained.
All of profiles have been compared with the logarithmic laws and the relevant zero-plane displacement d and roughness length Z0 have been obtained as 20cm and 1cm, respectively. The fluxes of turbulent transfer of heat, water vapor and CO2 have been calculated by the aerodynamic method and compared with each other. The amounts of heat energy required for the evapotranspiration and for the photosynthesis of rice plants have been also calculated and the heat budget of the net radiation flux has been considered briefly.抄録全体を表示PDF形式でダウンロード (1234K) -
日下部 正雄1958 年 14 巻 2 号 p. 54-56
発行日: 1958/10/31
公開日: 2010/02/25
ジャーナル フリーThere has been no objecctive and reasonable criterion in determining the rainless periods when for a practical purpose it is desired that any particular days, which actually had a certain amount of precipitation during those periods, are still counted as rainless.
The author presents that a day may be considered as rainless when the daily amount of precipitation on that day is less than the value of the corresponding potential evapotranspiration which is to be obtained from the daily mean temperature.
From those rainless periods thus obtained for Fukuoka covering the last 30 years, each of which lasted for more than 10 days, the number of their occurrences according to the durations, and the season of the year for which they are liable to occur, are studied.
As to those rainless periods, it is not their lengths of duration but their “intensities” that are important.
Then, expressing the indices for such intensities of rainless periods by the water losses which occurred throught out the whole period, the number of occurrences according to the indices, and the season of the year in which these periods are apt to occur, are also researched.抄録全体を表示PDF形式でダウンロード (454K) -
苹果の袋掛栽培の環境について中川 行夫1958 年 14 巻 2 号 p. 57-60
発行日: 1958/10/31
公開日: 2010/02/25
ジャーナル フリーIn order to research the difference of environment of fruits surface among a bare fruit, a fruit covered with a paper bag and that covered with a torn paper bag, the author carried out the obsevation of temperature of fruit surface (apple), air temperature, humidity in a paper bag, wind velocity and solar, sky radiation.
The results are as follows;
1) The upper surface temperature of the bare fruit, the fruit covered with paper bag and that covered with torn paper bag were higher than the air temperature with differences of 11-14°C, 5-6°C and 3-4°C, respectively, during day time as shown in Fig. 2.
2) The water vapor pressure in the paper bag was higher than that of air as shown in Fig. 3, and it is imagined that the water vapor pressure in the torn bag nearly epuals to that of air.
3) Owing to the paucity of change of environment the fruit covered with torn paper bag had a small sunburn than that covered with paper bag when the bag was removed.抄録全体を表示PDF形式でダウンロード (539K) -
果実内の温度分布について中川 行夫1958 年 14 巻 2 号 p. 61-64
発行日: 1958/10/31
公開日: 2010/02/25
ジャーナル フリーThe author suggested that temperature distribution in a fruit is influenced by heat conduction from fruit surface and respiration heat originated at inner parts of a fruit.
The differential equation is
∂u/∂t=κ2∂2u/∂r2+rb2 (1)
The boundary conditions are
(u)r=a=A sinωt (2)
(u)r=0=0 (3)
where u, κ2, a are the temperature, the thermal diffusivity and the radius of a fruit, respectively, and rb2 is the term about the resperation heat.
The required solution is thus
u(r, t)=b2(a2-r2)/6κ2+Aa√sin2hmr+sin2mr/r√sin2hma+sin2ma
×sin(ωt+tan-1sinhmacosmacoshmrsinmr-coshmasinmasinhmrcosmr/sinhmacosmasinhmrcosmr+coshmasinmacoshmrsinmr) (4)
and the temperature at the center of a fruit is
u(o, t)=b2a2/6κ2+Aa√m/√sin2hma+sin2ma
×sin(ωt+tan-1sinhmacosma-coshmasinma/sinhmacosma+coshmasinma) (5)
The temperature of water melon was measured and compared with calculated value from formula (4) as shown in Fig. 2.抄録全体を表示PDF形式でダウンロード (469K) -
矢吹 万寿1958 年 14 巻 2 号 p. 65-68
発行日: 1958/10/31
公開日: 2010/02/25
ジャーナル フリーThe exchange of heat energy on the field is very important and interesting problem. However the measurment of terrestrial radiation is not easy, and several methods have been proposed to measure the radiation flux.
This net-radiometer is one of the open types with a small blower to ventilate the horizontal thermoelectric sensing element to avoid the influence of the natural wind, and its construction and characters are described and are shown in Fig. 1, 2, 3 and 4.
As the examples used the instrument, the net-radiations of ground surfaces which were covered with different materials, as paper, glass etc., were measured and the results are shown in table 1.抄録全体を表示PDF形式でダウンロード (2807K) -
地形と風山本 良三1958 年 14 巻 2 号 p. 69-73
発行日: 1958/10/31
公開日: 2010/02/25
ジャーナル フリーThe author studied the relationship between the wind and the topography, using various acutual and model landforms, from an agricultural standpoint. The investigations were carried out in a hilly district of the Atsumi Peninsula, Aiti Prefecture, establishing many observation points on summits and hillsides, in valleys and on level lands. The observations of the wind were made mainly by using Nakaasa-type anemometers and many strermers and partially with smoke. And in order to conduct investigations into the micro behaviour of the wind, some indoor model experiments were carried out using a hot wire anemometer for the measurements of the wind velocities.
Results obtained were summerized as follows:
1) The relationship between an isolated hill and the wind around it is analogous to that between an object and the movement of water flowing around it.
2) In a valley the wind generally blows along the ridges of the valley regardless of the main wind direction and its velocity slows down gradually by the influence of the topography. But if the direction of the valley coincides with that of the main wind and the valley Is outside the range of the influence of the ridge standing to windward, the wind blowing through the valley suddenly adds strength.
3) In a dale and a pass the properties of the wind differ far from those on the outside.
4) The air flow near the ground is apt to be influenced by the smallest undulation of the ground. We may turn this relation between the air flow and the undulation to the best account in preventing the wind damage in the cultivated field.
5) It is very often that the direction and velocity of the wind changes every hour. In that case the correlation between the wind and the topography changes accordingly.抄録全体を表示PDF形式でダウンロード (813K) -
[I] 熱収支研究について内島 善兵衛1958 年 14 巻 2 号 p. 74-78
発行日: 1958/10/31
公開日: 2010/02/25
ジャーナル フリーPDF形式でダウンロード (829K) -
1958 年 14 巻 2 号 p. 79-80
発行日: 1958/10/31
公開日: 2010/02/25
ジャーナル フリーPDF形式でダウンロード (289K)
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