All issues
Volume 47, Issue 3
Displaying 1-8 of 8 articles from this issue
- |<
- <
- 1
- >
- >|
-
Tetsuo KOBAYASHI, Takehiro TAKEMASA, Shizuo HAYASHI, Kenji MIYAGAWA, Y ...1991 Volume 47 Issue 3 Pages 151-157
Published: December 10, 1991
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSA growing rate equation for the dry surface layer (DSL) in sand dune fields is developed. This equation makes use of the apparent jump discontinuity in volumetric water content at the boundary between the DSL and the moist underlayer (Δθ), as well as the soil-surface evaporation rate minus the upward water flux in the lower part of moist layers (qm). The evaporation rate exhibits a diurnal variation, while the flux qm decreases exponentially with a half-life much longer than the diurnal time period. Hence, there are diurnal as well as day-to-day variations in the thickness of the DSL. It is also shown that the Δθ exhibits a well-defined variation during the daytime hours, which mainly reflects the change in the soil temperature gradient across the DSL in response to the solar heating of the land surface.View full abstractDownload PDF (833K) -
Jung Eek SON, Tsuyoshi OKUYA1991 Volume 47 Issue 3 Pages 159-163
Published: December 10, 1991
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSAn optimum management of the nutrient solution in hydroponics needs the predicition of electrical conductivity (EC) of the nutrient solution. But theoretical predicition of EC of the solution containing many kinds of inorganic compounds like the nutrient solution has been impossible because of the complex interactions among ions. By considering EC decrement caused by the interactions approximately, two experimental equations (2) and (3) for predicting EC of the nutrient solution in hydroponics were developed. Parameters of the equations (2) and (3) were calculated statistically using the measured ECs(f) and ion concentrations of 180 kinds of nutrient solutions (0.5-6.0 mS/cm). Finally, the equations (2) and (3) were evaluated using the six samples of nutrient solutions and good agreements were obtained between the measured ECs (fs) and the predicted ECs (f1 and f2) with the precision errors of ±4.1 and ±6.2%, respectively.View full abstractDownload PDF (581K) -
Isamu NOUCHI1991 Volume 47 Issue 3 Pages 165-175
Published: December 10, 1991
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (1631K) -
Nobuhiko KAWASHIMA1991 Volume 47 Issue 3 Pages 177-182
Published: December 10, 1991
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (944K) -
Masataka KIYOHARA1991 Volume 47 Issue 3 Pages 183-189
Published: December 10, 1991
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (2093K) -
Takehisa OIKAWA1991 Volume 47 Issue 3 Pages 191-194
Published: December 10, 1991
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (576K) -
Geographisches Institut, Eidgenössische Technische Hochschule ZürichHitoshi TORITANI1991 Volume 47 Issue 3 Pages 195-198
Published: December 10, 1991
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (2483K) -
Commission for Protected Cultivation1991 Volume 47 Issue 3 Pages 199-200
Published: December 10, 1991
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (176K)
- |<
- <
- 1
- >
- >|