| JaLCDOI | 10.18926/fest/11630 |
|---|---|
| Title Alternative | Process of Acid Sulfate Soil Formation from the Viewpoint of Moisture Conditions on Coastal Muddy Soil and a trial of it's Amelioration |
| FullText URL | 001_135_141.pdf |
| Author | Adachi, Tadashi| |
| Abstract | According to recent soil survey data, it has been reported that acid sulfate soils cover areas of about 11,670,000 hectares all over the world and about 40% of those are in South-East Asia. Most of crops could not be grown on those areas without any amelioration due to low soil pH. This report consists of two parts. One is on acid sulfate soil formation in laboratory experiment. Another is on a trial of acid sulfate soil amelioration in field experiment. The results obtained on acid sulfate soil formation, in order to make clear the relationships between the process of oxidation of sulfur compounds and the moisture conditions (moisture suction) in coastal muddy soils, in laboratory experiment are summarized as follows; The concentration of sulfuric ions increase as oxidation of sulfur compounds contained in pyrite, etc. occurs, and as a consequence, the soil pH decreases in the coastal muddy soil (Fig.1). Especially, the soil pH decreased remarkably in the range of pF 2.3~3.4. The activity of soil microorganism takes part in this reaction by helping out with bringing about sulfur oxidation and formation of sulfuric ions. The pH decrease in the soil with autoclaved treatment was only slight at pF values lower than pF 3.0. Accordingly, it is concluded that the decrease of pH in coastal muddy soil occurred mainly due to soil microorganisms which oxidize sulfur compounds under the condition of higher-water than pF 3.0. The results of field experiment is summarized as follows; As a general rule, it is able to remedy the surface acidification of peat/acid sulfate soils by mixing lime dust with plough layer. However, the effect of mixed lime dust is easily disappeared in the area where the acidic ground water table is always high and moves up over the surface in rainy season. Therefore, it was carried out that several experiments for seeking protection against surface acidification due to capillary upward movement of acidic ground water by means of inserting a buffering layer of lime gravel (thickness of lime gravel layer =5㎝) between the top soil and the acidic subsoil (20 ㎝ depth) in the fields, Munoh series which is young acid sulfate soil, at the Narathiwat Land Development Center in South Thailand. The results of soil pH measurement carried out in the field in November of 1985, August of 1987 and September of 1990, it coincides with 2,4 and 7 years respectively after the beginning of the experiments, are shown in Table 3. In the plot of P2 and U1, application of lime dust to the plough layer can increase soil pH rapidly but it's residual effect is not so long. Within a 5 year period, the soil pH is likely to return to below 4. On the other hand, an underlaid lime gravel layer tends to improve the soil around the lime gravel only slight but steadily with time. Therefore, it is concluded that surface soil acidification caused by the upward movement of acidified ground water would be protected against, rapidly and continuously, by both mixing lime dust with plough layer and underlying lime gravel below plough layer. If acid sulfate soil areas would be used as upland fields, much of organic matters in soil are easily decomposed by drying. Therefore, it is suggested that it would be better for these areas to be used as paddy fields, also from the above results. |
| Keywords | Acid sulfate soil Soil microorganisms Moisture conditions Amelioration pH Sustainable effect |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 1996-03 |
| Volume | volume1 |
| Issue | issue1 |
| Start Page | 135 |
| End Page | 141 |
| ISSN | 1341-9099 |
| language | Japanese |
| File Version | publisher |
| NAID | 120002313380 |
| JaLCDOI | 10.18926/fest/11639 |
|---|---|
| FullText URL | 001_193_198.pdf |
| Author | Shimada, Kiyoshi| Nishimura, Sin-ichi| Fujii, Hiroaki| |
| Abstract | This paper presents a new method for prediction of consolidation settlements of soft grounds. The method is based on the theoretical result which shows that the settlement velocity of soft grounds non-improved or improved with sand drains decreases exponentially with time. Final settlements can be easily derived from the regression analysis for the relationship between the elapsed time and the observed settlement velocity. The method has advantages of its simplicity and capability to give the satisfactorily good estimate of the consolidation settlements, and also the support of the theoretical background. |
| Keywords | consolidation settlement prediction soft ground sand drains one-dimensional consolidation |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 1996-03 |
| Volume | volume1 |
| Issue | issue1 |
| Start Page | 193 |
| End Page | 198 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002314033 |
| JaLCDOI | 10.18926/fest/11623 |
|---|---|
| Title Alternative | Rain-water Retention of a Small-scale Upland Field in a Rainy Year and a Droughty Year |
| FullText URL | 001_143_149.pdf |
| Author | Yomota, Atsushi| |
| Abstract | From the standpoint of water resources development and environmental preservation, rain water retentivity of agricultural and forest lands are evaluated. Measurement of rainfall and runoff has been carried out at the reclaimed upland field of 4.55 ha since 1981. In this article, water retention characteristics of this study basin is compared in a rainy year of 1993 and a droughty year of 1994. In cases of rainfall less than 20mm, most of the rain water infiltrates into the soil layer. On the other hand, about 75% of a heavy rain, such as 300 mm in 1993, runs off the soil surface. Within the infiltrating rain water, the ratio of water which is kept by capillary action and can be used by crops is estimated to be less than 40% in months of rainfall more than 150 mm, but in months of rainfall less than 50 mm, it is estimated that more than 80% of rainfall can be used by crops. The ratio of monthly rainfall which contributes to base flow recharge is 0 to 12% regardless of rainfall amount. |
| Keywords | upland field monthly rainfall rain water retention effective rainfall base flow recharge |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 1996-03 |
| Volume | volume1 |
| Issue | issue1 |
| Start Page | 143 |
| End Page | 149 |
| ISSN | 1341-9099 |
| language | Japanese |
| File Version | publisher |
| NAID | 120002313677 |
| JaLCDOI | 10.18926/fest/11628 |
|---|---|
| Title Alternative | Secular changes of air temperature and precipitation in Okayama City. |
| FullText URL | 001_163_168.pdf |
| Author | Miura, Takeshi| |
| Abstract | In this paper, secular changes of air temperature and the amount of precipitation in Okayama city are discussed using observed values at Okayama meteorologiccal station. Special reference is made to 1993 and 1994 in which peculiar changes occurred. The results obtained are summarized as follows: (1) The increasing rate of the annual mean air temperature at Okayama city is 0.85℃/100y. This value is nearly equal to the average of Japan; 0.87℃/100y. (2) The increasing rate indicates seasonal changes, and the rate is high especially in April and May. (3) The rapid increase of the air temperature in the 1980s is due to removal of Okayama meteorological station from the edge of town to the center. (4) The annual mean air temperature in 1994 is 16.9℃, and the monthly mean temperature for July and August are 29.8 and 29.6℃ respectively. These values are new records at the Okayama station. (5) The air temperature in July and August, 1993 are higher than in 1980 when it was much colder in the summer. (6) The amount of precipitation does not show any secular changes. |
| Keywords | the air temperature secular changes Okayama city |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 1996-03 |
| Volume | volume1 |
| Issue | issue1 |
| Start Page | 163 |
| End Page | 168 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002313505 |
| JaLCDOI | 10.18926/fest/11613 |
|---|---|
| FullText URL | 001_055_064.pdf |
| Author | Watanabe, Masaji| |
| Abstract | We analyze some mathematical problems that arise in studies of phenomena observed in the cardiac action. We illustrate a method to characterize the response of a nonlinear oscillator to an external forcing, and introduce some numerical results. We also introduce some results of numerical computation in an example of a coupled system of an excitable system and a nonlinear oscillator. |
| Keywords | periodic forcing nonlinear oscillators excitable systems couples systems. |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 1996-03 |
| Volume | volume1 |
| Issue | issue1 |
| Start Page | 55 |
| End Page | 64 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002313699 |
| JaLCDOI | 10.18926/fest/11636 |
|---|---|
| FullText URL | 001_181_192.pdf |
| Author | Fujii, Hiroaki| Narita, Mutsuya| Cheng Chin Thai| Shimada, Kiyoshi| Nishimura, Shinichi| Ofori Emanual| |
| Abstract | This paper describes the prediction of seepage in the impervious zones of six embankment dams by seepage analysis. In addition, by making use of the available monitored pore water pressure data of the first filling of reservoir, back analysis was carried out to estimate the best fit seepage parameters. The estimated parameters were used for further prediction of pore water pressures in subsequent monitored durations with reasonable accuracy. The accuracy of prediction was evaluated quantitatively by the prediction difference and error index. The results show that the error indices in the upstream sides of the impervious zones are smaller than those in the downstream sides. |
| Keywords | Unsaturated soils fill dams pore water pressure back analysis FEM |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 1996-03 |
| Volume | volume1 |
| Issue | issue1 |
| Start Page | 181 |
| End Page | 192 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002313591 |
| JaLCDOI | 10.18926/fest/11619 |
|---|---|
| FullText URL | 001_115_119.pdf |
| Author | Takeshita, Yuji| Kono, Iichiro| |
| Abstract | The unsaturated soil hydraulic properties are essential data to predict the seepage behavior in the vadose zone. In this paper, a new experimental methodology of determining unsaturated soil hydraulic properties is proposed. The soil hydraulic properties are assumed to be represented by van Genuchten's closed-form expressions. Unknown parameters of this model are identified by using a optimization techniques. The optimization approach is nonlinear least-squares algorithm in corporating finite element analysis of one-dimensional nonsteady seepage flow. The advantages of the methods are in the possibility of identifying the optimal unsaturated soil hydraulic properties and diminishing experimental time. To evaluate availability of our proposed method, experimental results which are determined by proposed methods and conventional method are compared for decomposed granite soil. |
| Keywords | unsaturated hydraulic properties back analysis laboratory test groundwater |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 1996-03 |
| Volume | volume1 |
| Issue | issue1 |
| Start Page | 115 |
| End Page | 119 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002313807 |
| JaLCDOI | 10.18926/fest/11622 |
|---|---|
| FullText URL | 001_121_133.pdf |
| Author | Maeno, Shiro| Yamamoto, Tetsuo| Nago, Hiroshi| |
| Abstract | In this paper the theoretical procedure to analyze the dynamic behavior of highly saturated sand bed around a cylindrical block under the cyclic loading of water pressure is developed. The fundamental equations were derived for the axially symmetric coordinates. Then, the finite element equations were developed to solve these fundamental equations numerically. Finally, the numerical method was verified by experiments. |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 1996-03 |
| Volume | volume1 |
| Issue | issue1 |
| Start Page | 121 |
| End Page | 133 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002313416 |
| JaLCDOI | 10.18926/fest/11626 |
|---|---|
| FullText URL | 001_151_162.pdf |
| Author | Ndegwa George Maina| Yomota, Atsushi| |
| Abstract | Actual irrigation situation in a typical upland irrigation district was estimated by the water balance method during the 1993 rainy and the 1994 dry year periods. Soil moisture conditions were analysed for cases where daily district water use was supplied to all the cropped upland farms, and to reduced irrigation area percentages. Consumptive use was obtained through monthly weighted crop coefficients used to reduce penman's potential evapotranspiration. The moisture budget was examined at three levels of total readily available moisture, TRAM, i.e., 20,30 and 40 mm; the effect of upward capillary rise was also considered. The results of this study indicated that the actual moisture conditions in upland irrigated farms is influenced by irrigation area, cropping pattern, stage of crop growth and upward capillary rise in the farms. Actual irrigated area was within the range of about 44 to 100% of cropped area while upward capillary rise was between 0.1 and 1 mm day-1, TRAM level of 30 to 40 mm was considered most appropriate for the district. Monthly effective rainfall percentages from the water balance method were fairly close to that determined by the basic irrigation requirement method for some months. Basic irrigation requirement may therefore be considered to incorporate capillary water contribution. |
| Keywords | Upland irrigation TRAM Water balance Capillary water Effective rainfall |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 1996-03 |
| Volume | volume1 |
| Issue | issue1 |
| Start Page | 151 |
| End Page | 162 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002313861 |
| JaLCDOI | 10.18926/fest/11610 |
|---|---|
| FullText URL | 001_047_053.pdf |
| Author | Sasaki, Toru| Ishikawa, Hirofumi| Kajiwara, Tsuyoshi| Watanabe, Masaji| |
| Abstract | We treat the problem of water pollution by the method of a mathematical model. We illustrate the method of analysis with Kojima Lake. We analyze in-flow and out-flow of the lake, compute numerical solutions of the governing equations of the water flow and the pollutant. The simulation leads to the conclusion concerning the figure of Kojima Lake. |
| Keywords | Kojima lake Water analysis Finite element method |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 1996-03 |
| Volume | volume1 |
| Issue | issue1 |
| Start Page | 47 |
| End Page | 53 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002313787 |
| JaLCDOI | 10.18926/fest/11602 |
|---|---|
| FullText URL | 001_015_020.pdf |
| Author | Nakajima, Atsushi| |
| Abstract | Let A be a bialgebra and let S be a right A-comodule algebra which has an A-comodule subalgebra T with common identity. We show that if S is a separable extension of T, then for a left A-module algebra K, K♯S is a separable extension of K♯T. Similar result holds for left A-module algebras and right A-comodule algebras. |
| Keywords | Separable extension smash product module algebra and comodule algebra |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 1996-03 |
| Volume | volume1 |
| Issue | issue1 |
| Start Page | 15 |
| End Page | 20 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002313954 |
| JaLCDOI | 10.18926/fest/11611 |
|---|---|
| FullText URL | 001_065_076.pdf |
| Author | Kim, Hyun Bin| Tanaka, Yutaka| |
| Abstract | Partial least squares linear discriminant function (PLSD) as well as ordinary linear discriminant function (LDF) are used in pattern recognition analysis of writer identification based on are patterns extracted from the writings written with Hangul letters by 20 Koreans. Also a simulation study is performed using the Monte Carlo method to compare the performances of PLSD and LDF. PLSD showed remarkably better performance than LDF in the Monte Calro study and slightly better performance in the analysis of the real pattern recognition data. |
| Keywords | Writer identification Arc patterns Linear discriminant function Partial least squares |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 1996-03 |
| Volume | volume1 |
| Issue | issue1 |
| Start Page | 65 |
| End Page | 76 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002314147 |
| JaLCDOI | 10.18926/fest/11601 |
|---|---|
| FullText URL | 001_001_013.pdf |
| Author | Morimoto, Masaharu| Yanagihara, Mamoru| |
| Abstract | In transformation groups on manifolds, it has been an interesting problem to ask whether for a given finite group G, there exists a real G-module V such that dim VP >2dimV>P for all subgroups P of prime power order and such that VH=0 for certain large subgroups H of G. This paper provides GAP programs to show that S5 does not admit such a real S5-module V. |
| Keywords | GAP fixed point gap condition |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 1996-03 |
| Volume | volume1 |
| Issue | issue1 |
| Start Page | 1 |
| End Page | 13 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002313410 |
| JaLCDOI | 10.18926/fest/11635 |
|---|---|
| FullText URL | 001_169_179.pdf |
| Author | Abenney-Mickson Stephen| Miura, Takeshi| |
| Abstract | The SWAP93 model was used to predict how much capillary rise would occur in cropped fields. The experimental fields were located in a humid climate and it was thought that contribution from groundwater sources to total water use could be significant. In one field planted with soybean, the model predicted an average daily uptake of 1.3 mm; in another field planted with pumpkin, there was average daily uptake of 0.3 mm; and yet in a third field located in a vinyl house there was average daily uptake of 0.03 mm. These predictions represent about 38,7 and 1% contribution to total water use respectively. Even though there were no measured data to compare with, the results lie within the range of other works reported in the literature. |
| Keywords | Crop water use capillary rise SWAP93 model groundwater |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 1996-03 |
| Volume | volume1 |
| Issue | issue1 |
| Start Page | 169 |
| End Page | 179 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002313364 |
| JaLCDOI | 10.18926/fest/11615 |
|---|---|
| FullText URL | 001_077_089.pdf |
| Author | Okubo, Kenji| Morikawa, Hiroshi| Kimoto, Takashi| Tanaka, Yuji| |
| Abstract | Thermal 'staircase', a layer of constant temperature between the sheets of the steep gradients, was formed in the seasonal thermocline, which was 2.5 m above the bottom at a point of 18 m deep on the boundary slope in Lake Biwa. Following a sediment resuspension event when a moderate onshore wind blew, bed materials should be suspended up to the thermocline, then settled down forming a staircase above the turbid intrusion. Comparing the observed downward hear flux with the settling flux of sediment, it was found that double-diffusive convection would play an important role on the formation of the whole structure consisting of the staircase and turbid intrusion along with chemical anomalies and dense population of phytoplankters, which were fed by nutrients supplied from the bottom sediment under a typical condition of drought. Laboratory experiments were conducted to demonstrate the thermal and sediment processes in the stratified lake. Resuspension process due to surface and internal waves was examined using a tank with a sloping bottom, while the settling process was investigated by using a deep, diffusive tank. Formative process and scales of the staircase and intrusion were discussed relating with the intensity of resuspension and the buoyancy fluxes. |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 1996-03 |
| Volume | volume1 |
| Issue | issue1 |
| Start Page | 77 |
| End Page | 89 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002313571 |
| JaLCDOI | 10.18926/fest/11618 |
|---|---|
| Title Alternative | Transport Policy in United Kingdom -Concept and Practice for Better Transport Environment |
| FullText URL | 001_091_113.pdf |
| Author | Inouye, Hiroshi| |
| Abstract | The movement of transport policy in United Kingdom and its problems are surveyed in this paper. First, the general trend in transport, road program, and technologies to improve road safety and environment are introduced. Then, concepts to decrease traffic congestion are outlined, followed parking control strategies. Recent issues such as road pricing scheme in London, M25 widening plan, also deregulation and privatisation of transport and their problems are examined. |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 1996-03 |
| Volume | volume1 |
| Issue | issue1 |
| Start Page | 91 |
| End Page | 113 |
| ISSN | 1341-9099 |
| language | Japanese |
| File Version | publisher |
| NAID | 120002314020 |
| JaLCDOI | 10.18926/fest/11604 |
|---|---|
| FullText URL | 001_021_026.pdf |
| Author | Hora, Akihito| |
| Abstract | Let G be a topological group acting on S transitively from the left with a compact stabilizer K. We show that every isotropic (i.e. spatially homogeneous w.r.t. the G-actions) Markov chain on S can be lifted to a right random walk on G and give a one-to-one correspondence between the isotropic Markov chains on S and the totality of sequences of probabilities (ν,μ1,μ2,･･･) where ν is a probability on G/K and each μn is that on K＼G/K. |
| Keywords | random walk Markov chain |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 1996-03 |
| Volume | volume1 |
| Issue | issue1 |
| Start Page | 21 |
| End Page | 26 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002313549 |
| JaLCDOI | 10.18926/fest/11606 |
|---|---|
| FullText URL | 001_027_041.pdf |
| Author | Ishikawa, Hirofumi| |
| Abstract | The author has proved the dimension formula of the space of the Hilbert modular type cusp forms of weight two. We present further refinements of the dimension formula for a real quadratic number field Q(√D), and calculate it effectively. We tabulate the dimensions for square-free natural numbers D below 104 with the computer assistance. We also determine all the spaces of their dimension below 10. |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 1996-03 |
| Volume | volume1 |
| Issue | issue1 |
| Start Page | 27 |
| End Page | 41 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002313526 |
| JaLCDOI | 10.18926/fest/11608 |
|---|---|
| FullText URL | 001_043_046.pdf |
| Author | Kajiwara, Tsuyoshi| |
| Abstract | This paper contains some remarks supplementary to the previous paper [KW] concerning Hilbert C*-bimodules given from bundle constructions and a example given by this construction concerning the product type action on C*-algebras. |
| Keywords | Hilbert bimodule bundle tensor product |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 1996-03 |
| Volume | volume1 |
| Issue | issue1 |
| Start Page | 43 |
| End Page | 46 |
| ISSN | 1341-9099 |
| language | English |
| File Version | publisher |
| NAID | 120002313825 |
| JaLCDOI | 10.18926/fest/11645 |
|---|---|
| Title Alternative | Selective reduction of nitrogen oxide with propylene on alumina-zirconia prepared from Al chelate compound and Zr alkoxide |
| FullText URL | 001_199_204.pdf |
| Author | Kawabata, Koji| Yoshimatsu, Hideyuki| Yabuki, Tatsumi| Osaka, Akiyoshi| Miura, Yoshinari| |
| Abstract | An alumina-zirconia (AZ) composite powder was prepared by thermal decomposition of the organic precursors, which were synthesized from ethyl acetoacetate aluminium diisopropylate and zirconium n-butoxide. Specific surface area of AZ was higher than that of alumina-zirconia (ALK) prepared from aluminium sec-butoxide and zirconium nbutoxide. True density of AZ was lower than that of ALK. Selective reduction of nitrogen oxide with propylene in oxygen-rich atmosphere on AZ was superior to that on ALK. |
| Keywords | Al chelate compound Zr alkoxide alumina-zirconia specific surface area true density selective reduction of nitrogen oxide |
| Publication Title | 岡山大学環境理工学部研究報告 |
| Published Date | 1996-03 |
| Volume | volume1 |
| Issue | issue1 |
| Start Page | 199 |
| End Page | 204 |
| ISSN | 1341-9099 |
| language | Japanese |
| File Version | publisher |
| NAID | 110002291536 |
