JaLCDOI 10.18926/fest/11481
FullText URL 010_009_011.pdf
Author Kajiwara, Tsuyoshi| Sasaki, Toru|
Abstract An elementary proof of permanence for a simple mathematical model proposed by Nowak and Bangham. In many papers, permanence property is proved by theorems established by the general theory of dynamical system. In this paper, we present an elementary proof only using differential inequalities and the theory of linear differential equations with constant coefficients.
Keywords Permanence dynamical system pathogen
Publication Title 岡山大学環境理工学部研究報告
Published Date 2005-02-28
Volume volume10
Issue issue1
Start Page 9
End Page 11
ISSN 1341-9099
language English
File Version publisher
NAID 120002313596
JaLCDOI 10.18926/fest/11480
Title Alternative A Case Study on How to Teach English at University Adopting TOEIC (2) -Evaluation after three years-
FullText URL 009_167_178.pdf
Author Morokawa, Shigetake| Ogino, Masaru| Kanzaki, Ken-ichi|
Abstract Three years ago, we wrote an essay about our new English-teaching program that adopted TOEIC. We gave out questionnaires to the students with questions ranging from what they thought of English in general to what they thought of our new program. In the essay, we discussed some of the results. Even though students' response was relatively positive in this initial survey, we wrote in our conclusion that we would like to renew and reform our classes. Receiving feedback from students periodically would help us improve their English ability. In order to see the change of students' attitude toward English and also toward our program, we conducted the same research last February. This time the results were not as favorable. For example, the number of students who thought their English ability was poor increased and those who showed a positive attitude toward our program decreased. We discussed and wrote what we learned from those results. We raised the question whether there was a gap between what we tried to teach to the students and what they wanted from us. Possible reasons were discussed on why we could not succeed in stimulating the students into studying English further. In April 2003 Okayama University started a new English curriculum, in which the classes for proficiency tests including TOEIC were opened. Similar classes have been set at many other universities. This survey will be a help to the further development of English education adopting TOEIC.
Keywords TESOL TOEIC questionnaires team teaching
Publication Title 岡山大学環境理工学部研究報告
Published Date 2004-02-27
Volume volume9
Issue issue1
Start Page 167
End Page 178
ISSN 1341-9099
language Japanese
File Version publisher
NAID 120002313460
JaLCDOI 10.18926/fest/11479
FullText URL 010_001_007.pdf
Author Wang Xiao Dong| Ishikawa, Hirofumi|
Abstract The one-way hash function plays an important role in digital signatures and message authentication from the viewpoint of security. No effective attacking method has been discovered to the algorithm of hash function standard. In this study, we tried to attack SHA-256 in encryption mode using linear and differential cryptanalysis to solve a private key. We deduced that an estimate of the private key would require huge known and chosen plaintexts in both linear and differential cryptanalysis, and that it would be difficult to decipher SHA-256 in view of the required computation.
Keywords differential cryptanalysis encryption mode hash function linear cryptanalysis SHA-256
Publication Title 岡山大学環境理工学部研究報告
Published Date 2005-02-28
Volume volume10
Issue issue1
Start Page 1
End Page 7
ISSN 1341-9099
language Japanese
File Version publisher
NAID 120002313630
JaLCDOI 10.18926/fest/11478
FullText URL 009_163_166.pdf
Author Nakatsu Shogo| Tsuboi, Sadao|
Abstract Diels-Alder reactions of 5,5,5-trichloro-3-penten-2-one and ethyl 4,4,4-trichloro-2-butenoate with cyclopentadiene in the presence of a chiral Lewis acid gave exo-2-acetyl-endo-3-trichloromethyl-bicyclo[2.2.1]hept-5-ene and exo-2-ethoxycarbonyl-endo-3-trichloromethylbicyclo[2.2.1]hept-5-ene with 40% and 7% e.e., respectively.
Keywords asymmetric reaction Diels-Alder reaction asymmetric Diels-Alder reaction chiral Lewis acid trichloromethy group
Publication Title 岡山大学環境理工学部研究報告
Published Date 2004-02-27
Volume volume9
Issue issue1
Start Page 163
End Page 166
ISSN 1341-9099
language English
File Version publisher
NAID 120002313377
JaLCDOI 10.18926/fest/11477
Title Alternative Efficient Chain Extension Reaction of Poly (butylene terephthalate) by using Crystallization
FullText URL 012_167_171.pdf
Author Ihara, Seiji| Shiroma, Hisashi| Yamazaki, Shinichi| Kimura, Kunio|
Abstract Plastics are quite important materials for not only industrial usages but also our daily life. Many plastics are difficult to reuse because they are susceptible to UV, hydrolysis and so on leading to the reduction of molecular weight. Among them, poly (butylenes terephthalate) (PBT) is a valuable materials prepared by polycondensation reaction, and PBT has the same limitation to reuse. Hence, efficient chain extension reaction for recovered PBT has been needed to improve the properties damaged by chain scission. In this study, new chain extension reaction had been examined by using crystallization as pre-treatment. Isothermal crystallization at 161℃ concentrated the chain end-groups on the surface of the crystals, and chain extension reaction at 210℃, which was lower than the melting temperature of PBT, enhanced the molecular weight significantly compared with the reaction over the melting temperature. It concluded that the pre-treatment of crystallization was favorable for the efficient chain extension reaction and this result provided the new technology for the effective reuse of the plastics.
Keywords Polyester material recycle crystallization chain extension reaction
Publication Title 岡山大学環境理工学部研究報告
Published Date 2007-03-15
Volume volume12
Issue issue1
Start Page 167
End Page 171
ISSN 1341-9099
language Japanese
File Version publisher
NAID 120002314029
JaLCDOI 10.18926/fest/11476
Title Alternative Evaluation of Surface State of Ceramic Particles Suspended in Aqueous Solution by Potentiometric Titration Method
FullText URL 009_153_162.pdf
Author Miura, Yoshinari| Nanba, Tokuro| Shinoda, Masakatsu|
Abstract Surface states of ceramic particles such as SiO(2), Al(2)O(3), Si(3)N(4) and so on suspended in aqueous alkaline solutions were successfully and easily determined by a potentiometric titration method. Isoelctric point, iep and excess surface charge density were classified and evaluated for many ceramic particles from the view points of aggregation and dispersion of particles and solubility in aqueous solution.
Keywords potentiometric titration method isoelctric point excess surface charge density ceramic particle suspension aqueous solution
Publication Title 岡山大学環境理工学部研究報告
Published Date 2004-02-27
Volume volume9
Issue issue1
Start Page 153
End Page 162
ISSN 1341-9099
language Japanese
File Version publisher
NAID 120002313753
JaLCDOI 10.18926/fest/11475
Title Alternative Material Recycling of Municipal Waste Slags by Using Phase Separation of Glass
FullText URL 012_161_165.pdf
Author Imaoka, Takuya| Sakida, Shinichi| Nanba, Tokuro| Miura, Yoshinari|
Abstract A novel recycling process of municipal waste slags obtaining Fe-free colorless materials was developed by using a phase separation of borosilicate glass. B(2)O(3) was added to a simulated waste slag to promote the phase separation. The slag glasses were heat-treated above glass transition temperatures, from which phase separation was successfully induced. The phase-separated slag glasses were still colored in black due to Fe ions, and after soaking in acid, they were successfully bleached, obtaining colorless solids. According to compositional analyses, no Fe ions were confirmed in the remaining insolubles, indicating that Fe ions were preferentially incorporated into the borate-rich phases soluble in acid. The main constituent of the colorless solids was SiO(2) and the end products obtained in the present process were expected as an alternative of pure silica glass.
Keywords slag recycling colorless glass phase separation
Publication Title 岡山大学環境理工学部研究報告
Published Date 2007-03-15
Volume volume12
Issue issue1
Start Page 161
End Page 165
ISSN 1341-9099
language Japanese
File Version publisher
NAID 120002313957
JaLCDOI 10.18926/fest/11474
Title Alternative Agricultural trend of Inner Mongolia And Policy of Replacing Agriculture by Afforestation A Case Study of Zhuo Zi Xian, Wu Lan Cha Bu Meng
FullText URL 009_141_151.pdf
Author Du, Fu-Lin| Shinabe, Yoshihiro|
Abstract In this paper, Background of Policy of Replacing Agriculture by Afforestation is clarified by means of the relation of the local Agricultural trend due to performance of the policy, united it the influence in the living and agriculture production to farmer in Zhuo Zi Xian. The investigation to the feasibility of the policy is based on the statistics data and the investigation of the agriculture in Inner Mongolia of China. In progress of the Policy of Replacing Agriculture by Afforestation, change of crop structure and development of animal husbadry were mainly seen in local agriculture. It made "Replacing Agriculture by Afforestation" possible. In order to perform this policy, to prevent retrogradation and develop local Agriculture continuously, technological development and spread in the Sustainable Agriculture, Training of Products processing company and Exploitation of the Products market of Agriculture, Forestry and Stockbreeding should be considered in the future study.
Keywords replacing agriculture by afforestation policy make one stop two Return three Agricultural trend Inner Mongolia China
Publication Title 岡山大学環境理工学部研究報告
Published Date 2004-02-27
Volume volume9
Issue issue1
Start Page 141
End Page 151
ISSN 1341-9099
language Japanese
File Version publisher
NAID 120002313842
JaLCDOI 10.18926/fest/11473
Title Alternative Acceleration of Formation of Shish under Flow by Addition of Irregular Shaped Particles
FullText URL 012_157_160.pdf
Author Yamazaki, Shinichi| Wakabayashi, Kanji| Mizuma, Kenta| Kimura, Kunio|
Abstract We have shown that the shish was formed from the oriented melt composed of the elongated chains caused by dust particles within the melt via bundle typed nucleation under flow with low shear rate (γ=5s(-1)). This implies that dust particles effectively cause the elongation of chains within the melt. In this work, we observed the crystallization of polypropylene added with irregular shaped particles under shear flow by means of polarizing optical microscope. We prepared various shaped particles such as confetti-like, spherical and rock-like. We found that the size and asymmetric shape of additive particles play an important role for the acceleration of formation of shish.
Keywords shish crystallization polypropylene shear flow elongation injection molding
Publication Title 岡山大学環境理工学部研究報告
Published Date 2007-03-15
Volume volume12
Issue issue1
Start Page 157
End Page 160
ISSN 1341-9099
language Japanese
File Version publisher
NAID 120002313610
JaLCDOI 10.18926/fest/11472
Title Alternative Chemical Changes of Dredged Soil in Kojima Lake from the Viewpoint of Soil Reaction
FullText URL 009_137_140.pdf
Author Takemura, Koichiro| Adachi, Tadashi|
Abstract While dredged soil is increasing, the processing problem isn't solved. So it is expected to use effectively as the soil material. Although, to use dredged soil, the chemical characteristic must be grasped. It is because acidification cause material (pyrite) can be contained in dredged soil. It causes sulfulic ions when it touches air and has the possibility to become acidification. In this experiment, dredged soil in Kojima Lake was made clear that it contained in pyrite and acidified under the oxidation condition. Accordingly, when using dredged soil as ground resources, it is necessary to use as the soil material such as filling-up reclamation under the deoxidization condition.
Keywords dredged soil pyrite acidify soil moisture condition
Publication Title 岡山大学環境理工学部研究報告
Published Date 2004-02-27
Volume volume9
Issue issue1
Start Page 137
End Page 140
ISSN 1341-9099
language Japanese
File Version publisher
NAID 120002313330
JaLCDOI 10.18926/fest/11471
FullText URL 012_151_156.pdf
Author Chetin Amine Cifci| Ichiminami, Fumikazu|
Abstract More than billions of years, Earth activity and earthquakes have functioned as the most important part in shaping the physical features of our Earth, on both social life and environment. Its unavoidable results always change life styles and city's structures with its positive and negative effects. To diminish those negative effects or avoid precise earthquake hazard, informing society is very crucial that the strong awareness decreases the risk as seen from past experiences all around the world. The research technique is functioned as questionnaire and applied in the area to achieve more realistic information and to maintain the essential arguments. All along the study, it is tried to think up the earthquake phenomena well known and straightforwardly recognized by a considerable quantity of people. Consequently, it is observed in this study that; firstly, telecommunication is most selected item both before and after earthquake in the point of its effectiveness. Secondly, telecommunication tools more preferable though, public announcement more trusting for society as power of affection on personal decision mechanisms. Thirdly, as a new tendency after earthquake, internet preference increased by means of information source about earthquake.
Keywords Awareness of earthquake Importance of information Relative reliability of sources Internet and public announcement
Publication Title 岡山大学環境理工学部研究報告
Published Date 2007-03-15
Volume volume12
Issue issue1
Start Page 151
End Page 156
ISSN 1341-9099
language English
File Version publisher
NAID 120002313418
JaLCDOI 10.18926/fest/11470
Title Alternative Diversity of Agricultural Production and Its Change in Tottori Prefecture
FullText URL 009_121_135.pdf
Author Ichiminami, Fumikazu|
Abstract In this paper, diversity of agricultural production and its change was examined for some 45 years in Japan and for 1960, 1980, and 2000 in Tottori prefecture. The concept of entropy was used in order to measure the diversity of the agricultural production which consists of some sections. Agricultural production section in Japan has been diversified in the long run. The ratio of rice has been decreasing gradually for a policy of cutting back on the acreage under cultivation. Although the ratio of stock raising and fruits has increased, it tends in recent years to stagnate. The rate of vegetables has increased remarkably. Combination type for every municipalities was determined with the standard value A method, and complemented examination of agricultural diversity.
Keywords Agricultural Production Diversity Entropy Sustainability Tottori Prefecture
Publication Title 岡山大学環境理工学部研究報告
Published Date 2004-02-27
Volume volume9
Issue issue1
Start Page 121
End Page 135
ISSN 1341-9099
language Japanese
File Version publisher
NAID 120002313477
JaLCDOI 10.18926/fest/11469
Title Alternative Measurement of thermal conductivity in soils and application of de Vries model
FullText URL 009_117_120.pdf
Author Moroizumi, Toshitsugu| Sato, Yuichi| Sato, Koichi| Sasaki, Choichi|
Abstract Thermal conductivity of soil samples were measured using a twin transient-state cylindrical-probe method. The system of measurement consists of DC power supply, data logger, personal computer, 100cc soil sample, reference material sample, and two heat probes. The typical results were as follows: (1) Thermal conductivity of soils increased according to an increase of soil water content. (2) The thermal conductivity of Toyoura sand was larger than one of Kuroboku soil. (3) The thermal conductivity estimated by de Vries model had good agreement with the measured value.
Keywords Thermal conductivity Twin transient-state cylindrical-probe method de Vries model Volumetric water content
Publication Title 岡山大学環境理工学部研究報告
Published Date 2004-02-27
Volume volume9
Issue issue1
Start Page 117
End Page 120
ISSN 1341-9099
language Japanese
File Version publisher
NAID 120002313616
JaLCDOI 10.18926/fest/11468
FullText URL 009_111_116.pdf
Author Su Hai| Taniguchi, Takeo| Chouw Nawawi|
Abstract The study addresses the influence of bumpers as reduction measures at the bridge decks. The considered devices are steel spring, steel spring with additional viscous damper or steel spring with additional friction element. Gap between bridge decks remains. The reduction measure is placed at one end of the neighbouring girders. The considered earthquakes are the 1994 Northridge earthquake and the 1995 Kobe earthquake. For the nonlinear analysis a finite element method is used. The investigation shows that compared to the other measures the best reduction of the pounding force can be achieved with a friction device.
Keywords reduction measure earthquake response bridge girder pounding viscous damping friction
Publication Title 岡山大学環境理工学部研究報告
Published Date 2004-02-27
Volume volume9
Issue issue1
Start Page 111
End Page 116
ISSN 1341-9099
language English
File Version publisher
NAID 120002313773
JaLCDOI 10.18926/fest/11467
Title Alternative Rows-of-houses Preservation in Maniwa City of Katsuyama Area, Okayama Prefecture
FullText URL 012_141_149.pdf
Author Luo, Yanjuan| Ichiminami, Fumikazu|
Abstract The aim of the study is to explain the present condition of the rows-of-houses preservation policy of Okayama Prefecture and to examine the samples in Maniwa city, Katsuyama area. Besides, the interview investigation was mainly conducted for residents in the rows-of-houses of preservation area in Katsuyama for giving the concluding remarks about the findings. The traditional private houses in Katsuyama preservation area were partially restored in the 1985-89 and 1993-97 fiscal years by the subsidy from the prefecture. Furthermore, Katsuyamacho at that time founded the subsidy system for maintaining rows-of-houses preservation area (about 25.3 ha) independently in 1993, restored 9 private houses, and made and updated the shop curtains; "Noren". In the point of the observable items, the ground warehouse of structures with gable tile-roofing is visible and it is also in use. Moreover, a latticed window structure, a white wall, and a sea cucumber wall constitute the charm of new rows-of-houses. A stone pavement follows on the riverside at the site facing the Asahi River. There are the remains of an arrival-and-departure place of a flat boat and a brewery, etc. According to our investigation in 2002, the residents were satisfied with "It is easy to live quietly", "the beauty of a natural landscape", "harmony of rows-of-houses and a shop curtain", and "a historical atmosphere", but the recognition of "the creation of active rows-of-houses" was unexpectedly low. Therefore, cooperation between residents and informational sharing are much more required. Consequently, since both the visitors and the residents are satisfied very much with each facilities, such as the whole rows-of-houses, a samurai residence, a brewery, and a restaurant etc., town planning is well organized and attained the priority targets.
Keywords Rows-of-houses Preservation Katsuyama area Visitors Residents
Publication Title 岡山大学環境理工学部研究報告
Published Date 2007-03-15
Volume volume12
Issue issue1
Start Page 141
End Page 149
ISSN 1341-9099
language Japanese
File Version publisher
NAID 120002313778
JaLCDOI 10.18926/fest/11466
FullText URL 009_099_110.pdf
Author Dewan A.M.| Nishigaki, Makoto| Komatsu, Mitsuru|
Abstract Dhaka city, the capital of Bangladesh and home for more than 10 million people, has been affected by seasonal flooding almost in every year, however, the situation aggravates depending on rainfall and surrounding river waters. The aim of this paper is to delineate the flood extent in Dhaka city using digital elevation model (DEM), an integral part of geographic information system. Catastrophic floods of the 1988 and 1998 events are taken into consideration. Hydro-meteorological assessment of these events revealed that the 1988 flood was severe due to the lack of flood protection in the city together with transboundary flow of the major rivers while the 1998 flood was become deluge due to incessant monsoonal downpour along with early peaked of the river water levels. The 1998 event has done colossal damage in the city compare to the 1988 event. Flood extent estimation showed that DEM data is very precious to model inundation in the city, however, in order to be spatially explicit flood model, high resolution DEM is necessary. Finally, flood management issues are reviewed and found that combination of structural and nonstructural measures are necessary to help reducing flood induced losses and damage in the city.
Keywords Dhaka City Floods Digital Elevation Model 1998 and 1988 Floods
Publication Title 岡山大学環境理工学部研究報告
Published Date 2004-02-27
Volume volume9
Issue issue1
Start Page 99
End Page 110
ISSN 1341-9099
language English
File Version publisher
NAID 120002313678
JaLCDOI 10.18926/fest/11465
Title Alternative A Survey Study of Residential Awareness on Utilization Function of Agricultural Water and Its Maintenance --A case study in Niwase and Natsukawa of Okayama City, Okayama Prefecture
FullText URL 012_131_140.pdf
Author Makino, Tota| Matsuoka, Takanobu| Qi, Zhiyong| Shinabe, Yosihiro|
Abstract The agricultural water has manifold functions for farming at community level. However, along with the difficulties to maintain the agriculture water path that are caused by the decreasing of farmers and the aging of the society, the agricultural water is losing its functions even that as water resource for local community. This paper presents a survey of the residential awareness on regional water utilization to find the possibility for the maintenance of agricultural water path. Economic evaluation is tried for the regional warter utilization function. This study is carried out at a regional level that covers both farming households and non farmers. Following three points can be confirmed based on the results of questionnaire survey. Firstly, local citizens admit that the agricultural water does have some values (3,037 Yen per household per year). Secondly, the higher the environmental awareness is, and the longer the citizen has lived there, the higher evaluation to function of the agricultural water can be observed. Thirdly, even within those who is holding high evaluation to the agricultural water, it is thought to be quite difficult to maintain the agricultural water path due to the aging of the society and uneven distribution of the participants.
Keywords agricultural water manifold functions for farming at community level local citizens maintenance Contingent Valuation Method
Publication Title 岡山大学環境理工学部研究報告
Published Date 2007-03-15
Volume volume12
Issue issue1
Start Page 131
End Page 140
ISSN 1341-9099
language Japanese
File Version publisher
NAID 120002313592
JaLCDOI 10.18926/fest/11464
FullText URL 009_087_098.pdf
Author Kankam-Yeboah Kwabena| Gyau-Boakye Philip| Nishigaki, Makoto| Komatsu, Mitsuru|
Abstract Three principal river basins are found in Ghana and the Volta River Basin is the major one, covering about three -quarters of Ghana. The basin is shared with Mali, Burkina Faso, Cote d'Ivoire, Togo and Benin. Water from the Volta River Basin is used for drinking water supply, generating hydro-electric power, irrigation, inland fisheries and lake transport. The sustainable management of the Volta River Basin is thus of great importance. Land use activities in the basin are thus closely monitored not only in Ghana, but also in the other riparian countries as well. This paper presents information and data on the water resources and environmental management of the Volta River Basin in Ghana.
Keywords water resources environmental management Volta River Basin Ghana water utilization
Publication Title 岡山大学環境理工学部研究報告
Published Date 2004-02-27
Volume volume9
Issue issue1
Start Page 87
End Page 98
ISSN 1341-9099
language English
File Version publisher
NAID 120002313917
JaLCDOI 10.18926/fest/11463
Title Alternative Heat Budget on Rice Field
FullText URL 009_081_085.pdf
Author Yang, Dongmei| Iwata, Toru| Miura, Takeshi| Ohtaki, Eiji|
Abstract Experience of flux measurements over tall canopies has revealed that the eddy flux of sensible plus latent heat is about 30% smaller than the available radiant energy flux. A systematic observation was carried out to investigate the imbalance problem on rice field. The rice field represents a complex system consisting of rice plant, irrigated water and soil. Date obtained in this experiment show that appreciable understimations of sensible and latent heat fluxes are not recognized but understimations of 15 to 23% are counted in the soil heat flux.
Keywords Heat budget Eddy correlation method Sensible heat flux Latent heat flux Soil heat flux
Publication Title 岡山大学環境理工学部研究報告
Published Date 2004-02-27
Volume volume9
Issue issue1
Start Page 81
End Page 85
ISSN 1341-9099
language Japanese
File Version publisher
NAID 120002313468
JaLCDOI 10.18926/fest/11462
Title Alternative Comparison of micrometeorological environments inside and outside an oriental pickling melon greenhouse.
FullText URL 012_125_130.pdf
Author Morimoto, Yuji| Hirano, Emi| Miura, Takeshi|
Abstract The use of greenhouses has rapidly increased after 1965, and the area became 11 times of 1965 as of 2001. Meteorological conditions and soil moisture environments inside a greenhouse are significantly different from those in the open field. These differences should be understandable to establish accurate predictions of water consumption and evapotranspiration inside a greenhouse which play important roles in the design of any irrigation system. This study aims to estimate the micrometeorological conditions inside an oriental pickling melon greenhouse which can be used for evapotranspiration calculations. Therefore, micrometeorological data were measured inside and outside the greenhouse for the comparison purposes. The results of this study may be summarized as: (1) Solar radiation inside the greenhouse was decreased about 30% of that of outside it by plastic film and frame. (2) Net radiation during the daytime inside the greenhouse was almost the same as the absorbed total short-wave radiation. (3) The difference of daytime mean air temperature inside and outside the greenhouse was between 3 and 4 degree Celsius in day average. (4) Both relative humidity and saturation deficit inside the greenhouse were higher than outside, and those were affected by ventilation. (5) Wind speed inside the greenhouse was greatly affected by opening rate of the house side.
Keywords greenhouse micrometeorology oriental pickling melon
Publication Title 岡山大学環境理工学部研究報告
Published Date 2007-03-15
Volume volume12
Issue issue1
Start Page 125
End Page 130
ISSN 1341-9099
language Japanese
File Version publisher
NAID 120002313863