cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.14457/cu.the.2012.673
title: Perforation strategies for multi-layered gas condensate and dry reservoirs

description: Multilayered gas and gas condensate reservoirs in the Gulf of Thailand are generally limited in extent and dissected by numerous faults. A single area may consist of a large number of individually distinguished reservoirs. The method to gain production is to perforate the layers in the right sequence. In this study, the system of interest consists of dry gas and gas condensate reservoirs. Seven different perforation strategies are analyzed in order to maximize condensate and gas production. For two-layer reservoirs with depletion-drive gas-condensate reservoir on top and dry-gas reservoir at the bottom having permeability of 500 mD and thickness of 100 ft, the best perforation strategy to maximize condensate production and barrel of oil equivalent is to perforate the top reservoir first until gas production rate reaches half of initial production rate and then perforate the bottom layer while keeping the top zone open. As the thickness of the gas condensate and dry gas reservoir decreases, we should delay the perforation of the lower zone in order to preserve the amount of gas in the lower reservoir to be used to lift condensate at late times in order to maximize condensate production. However, in term of barrel of oil equivalent, stand alone perforation is best for thickness of 50 ft. As the permeability of the gas condensate and dry gas zones decreases, we should also delay the perforation of the lower zone in order to maximize condensate production and barrel of oil equivalent.
DOI: 10.14457/cu.the.2012.674
title: Chemical constituents from the stem bark of Erythrina stricta and E. subumbrans and anticancer activity

description: The investigation for chemical constituents and their biological activities from the Hexane and CH2Cl2 crude extracts of the stem barks of Erythrina stricta led to the isolation of six known compounds, p-hydroxybenzoic acid (1), osajin (2), derrone (3), erythinasinate (4), and a mixture of β-sitosterol (5) and stigmasterol (6). All isolated compounds were evaluated for their cytotoxicity on KB, HeLa, MCF-7, HepG-2, Colo205, and LLC cells. Compound 2 exhibited moderate cytotoxicity against both KB and Colo205 cells with IC50 values of 14.5 and 9.74 µg/mL and exhibited weak cytotoxicity against HeLa, MCF-7, HepG-2, and LLC cells with IC50 values of 21.8, 16.9, 17.4, and 16.3 µg/mL, respectively. Compound 3 exhibited weak activity against all the tested cells (KB, HeLa, MCF-7, HepG-2, Colo205, and LLC cells) with IC50 values of 15.8, 19.1, 17.3, 20.1, 15.2, and 17.1 µg/mL, respectively. Other compounds gave only very high IC50 values and were regarded as inactive to these cytotoxicity assays. The investigation for chemical constituents and their biological activities from the CH2Cl2 and acetone crude extracts of the stem bark of E. subumbrans led to the isolation of six known compounds, p-hydroxybenzoic acid (1), erythinasinate (4), and a mixture of β-sitosterol (5) and stigmasterol (6), hexacosyl trans-ferulate (7), and lupeol (8). All isolated compounds were evaluated for their cytotoxicity on KB, HeLa, MCF-7, HepG-2, Colo205, and LLC cells. Compound 8 exhibited moderate cytotoxicity against most of the tested cells including KB, HeLa, HepG-2, Colo205, and LLC cells with IC50 values of 14.0, 13.9, 13.7, 7.97, and 10.6 µg/mL respectively, whereas it exhibited weak cytotoxicity against MCF-7 cells with IC50 value of 16.7 µg/mL. On the other hand, other compounds gave only very high IC50 values and were regarded as inactive to these cytotoxicity assays.
DOI: 10.14457/cu.the.2012.675
title: The efficacy of (PDADMAC/PSS)9/PSS-co-MA coated polycaprolactone/Hydroxyapatite scaffold improve new bone formation : an invitro and in vivo study

description: Grafting material is necessary for large defect reconstruction. Autograft is an ideal treatment for bone reconstruction, however some limitation still. Therefore, development in an alternative ‘scaffold’ to replace autograft comes to attention. Polycaprolactone/hydroxyapatite (PCL/HAp) scaffold which had been proved morphology and mechanical properties could support bone formation. This study developed the PCL/HAp scaffold by the concept of polyelectrolyte multilayer coating with Poly(4-styrenesulfonic acid-co-maleic acid) sodium salt (PSS-co-MA), Poly(diallyldimethyl-ammonium chloride) (PDADMAC) and Poly(sodium 4-styrene sulfonate) (PSS). This technique had been proved on planar material as glass and PCL membrane that had better wettability and could promoted osteoblast differentiation and also induce bone formation in murine calvarials defects at 6 weeks. This PEM coating (layer by layer) was combined onto the PCL/HAp scaffold surface and evaluated the ability of cell adhesion, proliferation, differentiation and mineralization of MC3T2-E1 cells. The results showed PSS-co-MA coating scaffold surface expressed increasingly MTT and calcium deposition. For in vivo new bone formation, PSS-co-MA coating PCL/HAp scaffold was implanted into circular defect of rat femur bone. Histological analysis of bone formation increased from 1 weeks and completed in 6 weeks. From in vivo and in vitro testing indicated that the (PDADMAC/PSS)9/PSS-co-MA coated scaffold could be the material of choice for bone tissue engineering.
DOI: 10.14457/cu.the.2012.676
title: Separation of silver ions and silver nanoparticles using cloud point extraction for the determination by flame atomatic absorption spectrometry

description: In this research, a method for separation and determination of silver nanoparticles (AgNPs) and total amount of silver was proposed by using Triton X-114 based cloud point extraction (CPE) and flame atomic absorption spectrometry (FAAS). The separation of AgNPs from ionic silver species (Ag+) was achieved by addition of sodium thiosulfate solution (Na₂S₂O₃). The extracted AgNPs was concentrated into the surfactant phase and digested with H2O2 prior to the analysis by FAAS. The extraction of AgNPs from samples was performed by using 20 mM of (Na₂S₂O₃) at pH 3.The recovery of AgNPs was in a range of 86.74-87.95 %. The limit of detection (LOD) of AgNPs was 0.27 mg L-1. The total amount of silver was also determined by oxidizing AgNPs in solution to Ag+. L-cysteine was added to form a neutral complex with silver ions before CPE was performed. The recovery of total amount of silver was in a range of 93.31-95.76% when 20 mM L-cystein solution was used in the analysis of solutions containing 0.5-1.0 mg L-1 of total Ag at pH 1-5. The limit of detection (LOD) of the total amount of silver was 0.11 mg L-1.
DOI: 10.14457/cu.the.2012.677
title: Characteristics of seasonal wind and wind-driven in the gulf of Thailand

description: The gulf of Thailand is bounded by Latitude 6° to 14°N and Longitude 99° to 105°E. It is located on the continental shelf connecting to South China Sea via the southern entrance. The gulf is border by Thailand, Cambodia and Vietnam on the eastern, northern and western side respectively. The gulf receives high solar radiation throughout the year. The NE and SW monsoon controls the local weather around the gulf. The monsoonal wind plays an important role in controlling the wind pattern, rainfall over Thailand, and also controlling water circulation in the Gulf of Thailand. The project objective is to simulate wind regime over the gulf and wind-driven circulation in the gulf of Thailand during the year 2000-2002. The study time span cover La Niña, normal and El Niño period respectively. The study is accomplished through to use of WRF model and 2-D water circulation model. Wind regime from WRF model was the input to the water circulation model. Statistical analysis was performed on the wind data in order to study the effect of El Niño and La Niña events on the wind pattern over the gulf of Thailand. Wind pattern from the WRF model was comparable to the satellite (observed) wind. And wind-driven circulation was similar to the results of earlier studies. During rainy season, the westerly and southwesterly wind from the Indian Ocean caused the wind-driven current in the gulf and the upper gulf to flow in a clockwise direction. Small eddies existed some locations in the gulf. During winter, high pressure system from Siberia caused wind in South China Sea to flow from the east to gulf entrance. While inside the gulf, the wind deflected to NE wind and caused the wind-driven circulation in the gulf and the upper gulf to flow in a counterclockwise direction. During summer, wind from South China Sea blew from the east direction. While inside the gulf, the wind deflected to SE wind. And the SE wind deflected to S wind when entering the upper gulf of Thailand. The pattern of wind-driven current in the gulf was similar to that in during the winter. When easterly wind was strong near the lower eastern coast of the gulf, there would be a northward flow of water along the coast. The effect of the El Niño event increased wind speed over the gulf and deflect the wind direction by 10°. On the other hand, the effect of the La Niña event reduced wind speed over the gulf and deflects the wind direction by the same degree. The wind-driven circulation pattern did not change with the El Niño and La Niña event.
DOI: 10.14457/cu.the.2012.678
title: Multiple transmission power localization algorithms in wireless sensor networks based on support vector machines

description: Localization in wireless sensor networks is the problem of estimating the geographical locations of wireless sensor nodes. We propose a framework to utilizing multiple data sources for localization scheme based on Support Vector Machines. The framework can be used with both classification and regression formulation of Support Vector Machines. The proposed method uses only connectivity information, i.e. hop count data. Multiple hop count data sources can be generated by adjusting the transmission power of wireless sensor nodes to change the communication ranges. The optimal choice of communication ranges can be determined by evaluating mutual information between hop count data and nodes’ location. We consider two methods for integrating multiple data sources together; unif method and align method. The improved localization accuracy of the proposed framework is verified by simulation study.
DOI: 10.14457/cu.the.2012.679
title: Structural phase transitions of calcium and strontium under high pressure

description: The Group IIA metal, also known as alkaline-earth, undergoes the structural phase transitions under high pressure due to s to d orbital electron transition. It has been reported to possess several novel crystal structures, however, the full structural details has not been identified. In this thesis, structural studies of these metals have been carried out using computational method. Density Functional Theory (DFT) and Molecular Dynamics (MD) are the computation approaches which have been exploited to calculate the transition behavior. For calcium, the ambient crystal structure is the face-centered cubic (fcc) with space group. Under higher pressure, it transforms to the body-centered cubic (bcc) with space group at 5.4 GPa and then transforms to the Ca-III structure which is the β-tin structure with space group at 33.2 GPa. Finally, it transforms to the structure at 91.8 GPa. For strontium, at medium pressure range (20 GPa-40 GPa), structures were investigated by ab initio calculation and special interest has been given to the variation of exchange-correlation functional, i.e., Perdew Burke Ernzerhof (PBE) and screened exhange-Local Density Aproximation (sX-LDA). By using PBE potential functional in the calculation, the fcc structure shows the transformation to the bcc structure at 1.4 GPa and then to the hcp structure at 23.8 GPa. On the contrary, when using sX-LDA as a potential functional, the enthalpy calculation of β-tin structure is significantly lower than those of the hcp structure. Therefore, sX-LDA is the most suitable potential functional for this type of phase transitions as sX-LDA can provide a significantly improved result when compared with the experimental data.
DOI: 10.14457/cu.the.2012.680
title: The development of HIV-1 genotypic drug resistance testing for a low-cost alternative

description: Since Highly Active Antiretroviral Therapy (HAART) becomes the most active way to control HIV replication, genotypic drug resistance testing has played an important role for HIV medication. Commercial test kits have been invented and developed continuously. However, all of those commercial kits are especially designed for HIV-1 subtype B which is the major strain of Europe and America continent. In each year, Thailand National Health Control expenses massively in HIV-infected individuals. To reduce cost of expenditure, we developed methods for genotyping drug resistance testing. In-house genotypic drug resistance assay was designed and developed for HIV-1 non-B subtype assay. 99 plasma HIV-infected samples were performed by in-house method and compared with commercial kits. There was no statistically different in antiretroviral resistance result comparison between commercial kit assay and in-house assay (p&gt;0.05). This should be an alternative method for HIV drug resistance testing in resource-limited country.
DOI: 10.14457/cu.the.2012.681
title: Synthesis of hydrophobic CaCO₃ nanoparticles using stearic acid as surface modifier

description: Facile synthesis of hydrophobic calcium carbonate (CaCO₃) had been conducted via aqueous reaction route incorporated with stearic acid. Ammonium stearate (C₁₇H₃₅COONH₄) solution prepared from stearic acid (C₁₇H₃₅COOH) and ammonium hydroxide (NH₄OH) was used as substrate for modifying surface property of the synthesized CaCO₃, resulting in not only the nucleation and growth of CaCO₃ particles but also formation of hydrophobic surface of CaCO₃. The optimal initial calcium hydroxide Ca(OH)₂ concentration which providedunique particles size and morphology was 2 mM with 49% yield.The carbonation temperature was animportantfactorto regulate the formation of aragonite morphology. Needle-like aragonite was precipitated at 60 and 90 °C. However, the incubation temperature was a minor influence for precipitated CaCO₃ particles. In addition, morphology, crystallinity and functional groups on surface of CaCO₃ were characterized by scanning electron microscopy, X-ray diffraction spectroscopy and Fourier Transform Infrared spectroscopy. Image processing program was employed for examining linkages of particle physical characteristics and the synthesizing conditions. As a result, it could be implied that usage of stearic acid withcontrolof carbonation temperature would be essential for synthesizing nano-scalled CaCO₃ with hydrophobic property.
DOI: 10.14457/cu.the.2012.682
title: Effect of acute and chronic administration of dihydroergotamine on cortical spreading depression and trigeminal nociception

description: Dihydroergotamine (DHE) is a derivative of ergot alkaloids. Its efficacy is used for vasoconstriction of cranial vessels and can reduce pain in migraine headache. The overuse of DHE is still uncertain. The objective of this study was to investigate the effect of acute and chronic DHE administration in animal induced cortical spreading depression (CSD) and trigeminal nociception. The experiment was divided into 2 groups; the acute-treated group, Wistar rats were received 100 µg/kg DHE, i.v., after the 3rd depolarization waves of CSD was generated and the chronic-treated group, rats were received a once daily 100 µg/kg DHE, i.p., for 0, 7, 14, and 28 days. In the chronic-treated group, the last administration was performed at 30 minutes before CSD induction. The 0.1% dimethyl sulfoxide (DMSO) in 0.9% normal saline was given in the control rats of each group as a vehicle. CSD was induced using application of 3 mg solid potassium chloride and electrocorticogram was recorded within 1 hour and 2 hours for chronic-treated group and acute-treated group, respectively. Trigeminal nociception was studied in brain stem containing trigeminal nucleus caudalis (TNC). The expression of c-Fos protein was examined using western blot analysis. The results showed that acute treatment with DHE significantly decreased the quantity of c-Fos in TNC without the change in CSD patterns. On the contrary, chronic treatment with DHE presented the significant increase in area under the curve (AUC) of CSD waveforms and c-Fos in TNC for 14 and 28 days. These finding indicate that the chronic treatment with DHE can increase the cortical activity and c-Fos expression in trigeminal nociceptive system. This study could support the understanding of DHE-induced medication overuse headache and the pharmacological effect of this drug’s efficacy.
DOI: 10.14457/cu.the.2012.683
title: Engineering and physical properties of residual soil from landslide hazard area in Amphoe Chiang Klang, Changwat Nan, Thailand

description: Previous researches regarding landslide in Thailand have focused mainly to classify landslide hazard areas based on the analysis data in various factors such as topography, land-use, slope angle of soil slope, rainfall intensity etc. The field investigation and this research are aimed to geological setting, engineering properties of residual soil from parent rock including physical properties, properties of the soil shear strength decreases when the moisture content increases. In the study area, Ban Nong Pla, Amphoe Chiang Klang, Changwat Nan, found clastic sedimentary rocks are a parent rock including shale, sandstone, and siltstone. These residual soil and weathered rocks have a rate of high weathering therefore resulting to high susceptibility for landslide. As a result, the average value moisture content of soil, the average value specific gravity of soil, the average value liquid limit, and plastic limit are 24.83 %, 2.68, 44.93 % and 29.35 %, respectively. Plastic index is 15.58 % .Permeability value of soil is between as 9.36E-06 - 6.81E-07 cm/sec, respectively. Soils in the study area are classified by Unified Soil Classification System including ML- CL, CL- ML, ML- OL, SC and SM. The cohesion of soil values ranges from 0.096 to 1.196 ksc and angle of internal friction is between 11.51 - 35.78 degrees, respectively. Based on three resistivity lines survey, thickness of soil is between 2-9 m depth. The thickness of soil overlying on rock basement is important for calculating the volumetric of possible collapse. In conclusion, the result show that the failure slopes are greater than or equal 25 degrees, where soil profiles are overlying on the weathered clastic sedimentary rocks with high natural water contents. The change of factor of safety will occur where the soil depth between 2-5 m is located close to the depth of the actual slide zone.
DOI: 10.14457/cu.the.2012.684
title: Optimal Electrical Submersible Pump (ESP) design using variable speed technique for varing well conditions

description: In this study, reservoir simulation is applied to predict the performance of the fluid rate and bottom-hole pressure. The vertical lift performance is used to estimate the discharge pressure required to lift fluid to the surface. The results from reservoir simulation together with vertical lift performance are used to design the number of pump stages and compare with industrial practice. Water and solution-gas drive reservoir were considered to investigate the pressure behavior and determine the number of pump stages and the pump model. From the results, it was found that the specific gravity of fluid mixture has a significant influent in number of pump stage. In the case of water drive reservoir has proved that the larger aquifer will require a higher number of pump stages than smaller aquifer. For solution-gas drive reservoir, once the solution gas vaporizes as a free gas, it has a significant effect of reducing fluid density, resulting in number of pump stage reduction. Finally, the number of pump stages calculated from conventional design with 10%, 25% and 50% reduction factor was compared with the proposed method. The numbers of pump stages calculated from conventional design with all reduction factors are underestimated when compared with the results from the simulation in the fixed speed application. In the variable speed application, only 50% reduction factor in the conventional design can satisfy the requirement when compared to simulation results. However, overestimation of pump stages happens in many cases when 50% reduction factor is used.
DOI: 10.14457/cu.the.2012.685
title: Effect of ground subsidence on piled raft foundation

description: Extensive researches for piled rafts have been performed but the evaluation of their behavior in ground subsidence condition is still a challenge. In this study, centrifugal tests and finite element (FE) analyses were performed in order to investigate the effect of ground subsidence on load distribution between piles and raft, foundation settlement as well as moment and shear in raft. Six cases of centrifugal tests consisted of group 1 (soil condition 1) with case 1: raft alone, case 2: piled raft (s = 2d), case 3: piled raft (s = 4d) and group 2 (soil condition 2) with case 4: raft alone, case 5: friction piled raft (s = 4d), case 6: end-bearing piled raft (s = 4d) were conducted under centrifugal force field of 50g. The centrifugal test results can be concluded as followed; 1) foundations settled almost linearly with ground subsidence, 2) as piled spacing increases, settlement of foundation increases and axial load of piles increases, 3) negative skin friction of end-bearing piled raft was much larger than that of friction piled raft in ground subsidence condition. After centrifugal tests had been conducted, parametric studies were made for centrifugal piled raft models and three cases of piled rafts on Bangkok soil (case 1, case 3 and case 3 with levels of raft at -15 m, -7.5 m and + 0.0 m, respectively) under ground subsidence condition by a commercial finite element analysis program (Plaxis 3D). The calculations were done by drained, plastic analysis with effective parameters. Results showed that load-settlement curves, load distributions between piles and raft, axial force of piles, average and differential settlements, raft moment and shear were significantly affected by number of piles, Young’s modulus of soil, pattern of loads, raft thickness, piled spacing and ground water levels.
DOI: 10.14457/cu.the.2012.686
title: Numerical semigroups on ℕxℕ

description: The notion of numerical semigroups on ℕxℕ is defined similarly to numerical semigroups on ℕ. We investigate subsets of ℕxℕ which generate numerical semigroups on ℕxℕ. Moreover, we define and investigate irreducible and symmetric numerical semigroups on ℕxℕ. We provide some characterization of irreducible and symmetric numerical semigroups on ℕxℕ. Finally, we study conditions of numerical semigroups on ℕxℕ that can be expressed as an intersection of symmetric numerical semigroups on ℕxℕ.