Testing and modeling of unsaturated interfaces.

A conventional fully automated direct shear test device was modified to achieve the objectives of this study. The newly developed device, called the Unsaturated Interface Direct Shear Apparatus (UIDSA), was equipped for applying and maintaining suction as well as net normal stress. The UIDSA can be used to conduct constant water content and constant suction tests on unsaturated soil and unsaturated interfaces.The performance of the newly developed device was checked and effects of net normal stress, suction, and roughness were investigated. Net normal stresses of 105, 140, and 210 kPa were used and were conducted under constant suction values of 20, 50, and 100 kPa.An existing elastoplastic constitutive model was modified to predict the behavior of interfaces between unsaturated soil and steel. The model is applicable for the constant net normal and constant suction conditions. Model parameters are function of net normal stress, suction, and surface roughness. Predictions made with the modified elastoplastic model agreed well with the experimental results.Results presented in this study suggest that the maximum shear stress of interfaces between unsaturated soil and steel is a function of net normal stress and suction. As net normal stress and suction increased, so did the shear strength. The results of this study indicate that matric suction contributed to the peak shear strength of unsaturated interfaces; however, residual shear strength did not vary with the matric suction. As opposed to the matric suction, variation in net normal stress affected both peak and residual shear stress. The influence of matric suction was more pronounced in soil than interfaces. Similar to soil samples, the rough interface showed increase in dilatancy with increase in suction, whereas the smooth interface did not show dilatancy behavior.Major device modifications included the construction of an air pressure chamber and testing cells for holding soil and counterfaces, addition of high air entry porous stones, addition of a pore water and pore air control system, and other modifications to accommodate the new apparatus. For saturated soil testing, a High Air Entry Porous Disk (HAEPD) was fixed in the bottom half of the shear box, whereas for interface testing the HAEPD was fixed in the top platen and was placed on top of the soil during testing.The extended Mohr-Coulomb failure criterion provided a good model for describing variation in interface shear strength as a function of net normal stress and matric suction. Shear strength parameters for soil and interfaces were determined to define the extended Mohr-Coulomb failure envelope.Research was conducted at the University of Oklahoma to examine the behavior of interfaces in unsaturated soil. The objectives of this research were to: (1) design and construct an apparatus for testing unsaturated interfaces and soil; (2) test unsaturated soil and interfaces in the new device to study the strength and volumetric behavior of unsaturated soil and interfaces; (3) examine application of the Mohr-Coulomb failure criterion to unsaturated interfaces; and (4) develop an elastoplastic model to account for the effect of suction and net normal stress on the behavior of an unsaturated interface

The biochemistry of lipid accumulation in Mucor circinelloides and Mortierella alpina

1. The profile and biochemistry of growth and lipid accumulation in M. circinelloides and Mt. alpina were investigated. 2. A nitrogen-limited condition was vital in triggering lipid accumulation in both fungi, which was in agreement with previous work reported in oleaginous yeasts (Botham and Ratledge, 1979; Boulton and Ratledge, 1984). Good growth and lipid production by M. circinelloides were obtained only when it was grown in fermenters. Growth in stirred bottles (whirlipots) did not result in high lipid yields. This was caused by the anaerobic nature of cultivation in the whirlipots which affected the utilization of ammonium by the cells. As a result the cultures became carbon-limited instead of nitrogen-limited. Conversely, in a fermenter culture which had an efficient aeration, the culture reached a nitrogen-limited condition at an early stage of the incubation which led to a higher lipid production of the cells. 3. The lipid production in both fungi increased in parallel with the increase in the C:N ratio of the medium but the fatty acid compositions were not affected. 4. Ten enzymes potentially linked to the regulation of lipid biosynthesis (fatty acid synthase, acetyl-CoA carboxylase, ATP:Citrate lyase, AMP:deaminase, carnitine acetyl transferase, malic enzyme, glucose-6- phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, NADP:isocitrate dehydrogenase and NAD:isocitrate dehydrogenase) were detected in both fungi. In both fungi, the profile of all enzymes stated above was similar with the activities increased coincidentally with the depletion of ammonia in the medium. 5. The only differences in the enzymatic profiles of the two fungi was the early depletion of ME activity in M. circinelloides where it disappeared after approximately 40 h of incubation, coincident with the cessation of lipid accumulation, although other key enzymes of lipid biosynthesis (FAS, ACC and ACL) together with the activities of other NADPHgenerating enzymes were still active and the glucose was still present. Conversely, ME in Mt. alpina culture was present until the late stage of fermentation and the cell lipid continued to increase until the end of the fermentation. This suggests ME is a major provider of NADPH for lipid biosynthesis which was in agreement with previous observations in Aspergillus nidu/ans (Wynn and Ratledge, 1997) and M. circinelloides (Wynn et al., 1997). 6. The depletion of ME activity in M. circinelloides after approximately 40 h of incubation was as a result of the cessation of the protein from being synthesized, triggered by the depletion of ammonium in the culture. This - was evident as malic enzyme activity returned after its initial depletion when ammonium tartrate was added into the culture. Also, the restitution of malic enzyme activity was prevented when cycloheximide, a protein synthesis inhibitor, was added simultanously with the addition of ammonium tartrate. 7. The NAD:isocitrate dehydrogenase from both fungi showed an increased affinity for its substrate, isocitrate, in, the presence of AMP. However, the enzyme did not show an absolute requirement for AMP for its activity as it could still be activated in the absence of AMP at a saturating concentration of isocitrate. 8. ME was purified some 20-fold purification from both fungi. Both showed a similar Km values for NADP (approximately 0.04 mM) but a slightly higher Km value for malate was obtained in Mt. alpina compared to M. circinelloides (1 mM and 0.4 mM, respectively). 9. ME from both fungi showed various degrees of inhibition by tartronic acid, oxaloacetate, palmitoyl-CoA and oleoyl-CoA. At 10 mM, tartronic acid caused approximately 40 % inhibition in the activity of ME from both fungi while OAA inhibited ME from M. circinelloides more strongly (70 %) than that from Mt. alpina ( 45 % ). At a final concentration of 1 mM, palmitoyl-CoA and oleoyl-CoA caused a 100 % inhibition on ME from M. circinelloides and approximately 90 % on ME from Mt. alpina. 10. FAS purified from both fungi showed a similar Km values for malonyl-CoA and acetyl-CoA (approximately 0.013 and 0.016 mM, - respectively) while a higher Km value for NAOPH was observed in Mt. alpina compared to M. circinelloides (0.038 and 0.01 mM, respectively). 11. Despite a range of experiment using different approaches, no direct evidence of a physical association between FAS and ME was obtained when experiments were performed to observe the formation of complexes between the two enzymes in vitro

親電子物質の解毒メカニズムを介するパースルフィドの新規生体保護作用

要約のみTohoku University赤池　孝章課

STUDIES OF DROUGHT TOLERANCE OF HARD RED WINTER WHEAT (\u3ci\u3eTRITICUM AESTIVUM \u3c/i\u3e L.) CULTIVARS IN NEBRASKA

In Nebraska, about 75% of the wheat production is in the western half of the state, and about 92% of the winter wheat acreage is in dryland production, where productivity is limited by low and/or uncertain rainfall. We have investigated the effects of water stress on few established winter wheat (Triticum aestivumL.) cultivars, which are known for their superior adaptation to either rainfed or irrigated wheat production systems in western Nebraska. We also began a study to investigate the variation in the root system architecture to confer drought tolerance in winter wheat. The objectives of this study were to investigate the effects of water stress on root and shoot growth of winter wheat cultivars, and also to characterize the root system architecture (RSA) traits of winter wheat cultivars in order to evaluate their drought tolerance under limiting water conditions. The root length, root dry matter, root-to-shoot length ratio and root-to-shoot mass ratio of the three cultivars were significantly greater in the water stress than well-watered conditions. Results from the water stress experiment showed that Goodstreak is a drought tolerant cultivar due to its longest root length and high root dry matter. Based on the RSA phenotyping of the 3-week old water-stressed plants, Goodstreak had the highest total root length, total root length density, projected area of roots and network root length distribution. Under water stress conditions, Harry demonstrated a shallow root system with low root and shoot dry matters but displayed the highest root-to-shoot length ratio. It appeared that Harry utilized less water and invested less energy into dry matter under water stress. Our findings support the fact that Wesley performed well in irrigated wheat production systems in Nebraska because of its high shoot and root biomasses. This study leads us to suggest that Wesley is a drought sensitive cultivar because it uses the available soil moisture at ‘uneconomical’ and ‘unsustainable’ rate compared to Harry and Goodstreak. Advisors: P. Stephen Baenziger and Harkamal Wali

Waqf Higher Education: Implementation Model In University College Bestari (UCB), Terengganu, Malaysia

Waqf higher education was an important asset in developing knowledgeable intellectuals. This waqf higher education was a successful institution that uses waqf as it source of operation. It can be seen through the model of College University Bestari (UCB) in the implementation of higher education waqf. The objective of this writing is to focus on the historical background, the development of waqf asset, contribution and beneficial distribution of waqf property as well as challenges and prospects of higher education in Malaysia. The analysis result found that UCB had been successfully expanded the waqf funds through the waqf scheme of land lot by getting approval from Terengganu Islamic Religious and Malay Customs Council (MAIDAM). Thus, the implementation of educational waqf held by UCB can be used as a model to other educational institutions in order to develop waqf property and generate revenue. Therefore, the model that existed in this waqf institution need to be systematically planned and implemented to ensure that it can be a guarantee and catalyst towards education finance system of the Muslim community

Prediction of Asphaltenes Behaviors in Reservoir during CO2 Injection

Asphaltenes study for its precipitation has been a regular study for a field which has its Enhanced Oil Recovery (EOR) by Water Alternating Gas (WAG) technique. This technique uses CO2 gas injected into the reservoir alternately with injection water. This technique will results in better field ultimate recovery. Unfortunately, besides increasing the recovery factor of the hydrocarbon, the presence of CO2 cause a slight change in the oil composition, this change destabilizes the asphaltenes in the crude oil. As the asphaltenes is no longer stable in the crude oil, it will precipitate. This Asphaltenes precipitation creates major problems to the production performance of particular reservoir. Problems encountered as the results of asphaltenes precipitation are it can plug the wells and causes separation difficulties at the separation facilities. For a long time in the industry, remedial approach for this problem has been practiced by the operator instead of preventive approach from the beginning of well life. Asphaltenes Onset Pressure (AOP) is the very important in understanding the asphaltenes behavior in the reservoir [2]. AOP are mostly conducted using a mixture of reservoir fluid and the injection gas. However this approach only shows the static behavior of asphaltenes in reservoir. AOP will be measured using Solid Detection System, (SDS) using Near InfraRed (NIR) technique. Besides of experimental study, AOP can be predicted by mathematical modeling. This numerical method of finding AOP has been incorporated in the simulation software. In addition some simulation software can calculate the possible amount of asphaltenes precipitate. In some case of the cases shows that results from the static analysis of asphaltenes behavior is inconsistent with the real field fact, there is occurrence of asphaltenes precipitation at the region where no precipitation estimated using static asphaltenes behavior of asphaltenes precipitation envelope. For better understanding of asphaltenes precipitation, dynamic behavior of the asphaltenes in the reservoir needs to be understood for a realistic risk evaluation. This research is to investigate the behavior of asphaltenes in the reservoir by developing the Asphaltenes Precipitation Envelope (APE), calculate the amount asphaltenes precipitate and also determine the AOP of the crude oil

Analysis of Existing High-Rise Reinforced Concrete Structures in Malaysia Subjected to Earthquake and Wind Loadings

The purpose of this study was to investigate the effect of earthquake and wind loading on high rise structure in Malaysia. Conservatively, structural design in Malaysia overlook the significance of both loading (earthquake and hurricane) as they rarely take place in this region. However, occurrences of several tremors in neighbouring countries were enough to put us in fear. So, it is the time for us to revise existing structures to check for their reliability in facing any unforeseen natural disaster. This paper will be the key for any enhancement necessary to be implemented to our existing structures. The method of study mainly involves extended analysis of high rise frame structure and its behaviour towards movement and shakes in complying with UBC 1997 and IS 1893. Starting with simple vertical load analysis and then imposing earthquake and wind loading, the integrity of the frame structure is analysed. The behaviour in term of displacement, and the serviceability limit state of a particular structural will be studied and evaluated in order to quantify the maximum magnitude of lateral loads whereby a rigid frame structure could withstand before it starting to fail. This study analytically proves the outstanding performance of gravity designed structure towards typical wind and seismic conditions in Malaysia (35m/s for wind speed and 0.03g for seismic). However, existing structures in Malaysia without lateral loads design are expected to fail whenever wind and seismic forces are going beyond the typical conditions. The whole analysis demonstrates the understanding of certain code of practices, establish the ability of analysing and deducing the behaviour of structures, handling existing software, and interpreting the results and data to provide relevant comments and modifications whenever needed

Systematic Review of Cost Overrun Research in the Developed and Developing Countries

For decades, reputation of the construction industry has been tainted by poor cost performance caused by project cost overrun. In addition, studies by scholars worldwide have also found cost overrun to be more serious in developing countries compared to the developed countries. Despite the numerous researches addressing the issue of cost overrun in the construction industry through the years, the issue remains. Acknowledging that maintaining good cost performance is a key factor of project success and that the issue has persisted for decades, this study aims to explore the distinction of cost overrun studies that has been conducted between developed nations and developing nations. In achieving this aim, a systematic literature review is performed by following the integrative steps of PSALSAR (Protocol, Search, Appraisal, Synthesis, Analysis and Report) and PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) for screening and selecting the retrieved studies. The synthesis and screening of literatures have yielded with 152 articles which are then classified into their countries, developed countries (44) and developing countries (108). The results indicated a significant difference in the domain of research on cost overrun between the 2 nations. Despite the numerous studies on cost overrun in the developing nations compared to developed nations, the majority of the studies are not directed to any specific type construction while developed nations have moved forward to focus on more specific projects. The project with the highest attention in the developed nations is transport infrastructure construction projects, particularly rail infrastructure projects. The findings of this study have shown that there have been broad studies conducted on cost overrun in both developing nations and developed nations. However, there is a slight lacking in comprehensiveness of cost overrun studies in the developing nations, perhaps future studies on cost overrun in developing nations can be directed to more specific areas of construction projects such as those that have been performed by researchers of the developed nation