cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.14457/cu.the.2015.202
title: The effect of calcination atmospheres of sol-gel TiO2 on the catalytic properties of Pt/TiO2 catalysts in selective hydrogenation of 3-nitrostyrene

description: Nanocrystalline anatase TiO2 were synthesized by a sol-gel method and calcined under H2, air, N2, O2 and Ar atmosphere at 350 ̊C for 2 h and used as the supports for preparation of 0.5%Pt/TiO2 catalysts by incipient wetness impregnation (IW) method. The characteristics and catalytic properties of Pt (0.5wt% Pt) were analyzed by X-ray diffraction (XRD), N2-physisorption, X-ray photoelectron spectroscopy (XPS), H2-temperature programmed reduction (H2-TPR), infrared spectroscopy of adsorbed CO (CO-IR), CO-pulses chemisorption, electron spin resonance (ESR) and transmission electron microscopy (TEM). The 0.5%Pt supported on the TiO2 calcined under H2 and N2 atmosphere exhibited the best catalytic performances. High conversion of 3-NS (~70%) with high selectivity to 3-VA (&gt;90%) could be obtained after 20 min reaction time upon reduction at 200 ̊C. The catalytic activities of Pt/TiO2 were correlated with Pt dispersion and the selectivity of 3-VA desired product was related to the presence of low coordinated Pt sites and the metal-support interaction, which were influenced by defects on the TiO2 support. Preparation by the strong electrostatic adsorption (SEA) method improved the conversion of 3-NS from 29% to 64% of the Pt/TiO2-air catalysts but for the Pt/TiO2-H2, preparation by SEA method did not improve both conversion of 3-NS and 3-VA selectivity, due probably to that the catalyst already had high Pt dispersion, comparing to the one prepared by the incipient wetness impregnation method.
DOI: 10.14457/cu.the.2015.203
title: BASALT RESOURCES IN LOPBURI PROVINCE: A POTENTIAL RAW MATERIAL FOR BASALT FIBER PRODUCTION

description: Apart from a good host of ruby and sapphire, basalts and basaltic rocks can be used for other purposes, especially as producing construction material and making basalt fibers. Basalt has been widely used as concrete aggregate, pavement aggregate, railroad ballast and dimension stone. Not only these conventional applications, but also high quality fiber can be drawn from molten basalt with outstanding mechanical and chemical advantages comparing to hazardous asbestos fiber. Having higher strength and more stable in alkalinity than E-glass, basalt fiber is cheaper than the high-strength-low-density carbon fiber. With high thermal and abrasion resistance, basalt fiber could replace asbestos in various usages. Although all basalt can be used to make fiber, its quality depends largely on mineralogy, chemical composition and recrystallization behaviors of basaltic melts. The aim of this research is to evaluate the suitability of basalt resources in Lopburi Province, Thailand for making basalt fiber. Integrated results of petrological analysis, mineralogical and geochemical investigation as well as basalt melts’ characterization are presented in this research to delineate the suitability of the basalt resources for producing fiber. The complex geological evolution in central Thailand introduced very high variations of basalt composition and genesis. In some occurrences, basalt found highly altered due to the flow of basaltic lava over pre-existing rhyolitic layer, making it more sensitive to weathering. Meanwhile, some basalt deposits might be metamorphosed through which it makes changes in mineral and chemical compositions. However, fresh basalt to andesitic basalt was also found in some areas, which might be suitable for making fiber due to its unchanged mineralogical and chemical composition. Covering approximately one fourth of the total area of the province, Lopburi basaltic rocks are situated fairly close to a number of industrial zones, where are very advantageous for basalt fiber production.
DOI: 10.14457/cu.the.2015.204
title: The Pre- Feasibility Study of Gold Mine Development, A Case Study of Sepon Deposit, Savannakhet Province, Lao PDR

description: This study is about the pre-feasibility study of gold mine development in Lao PDR. The research area is located at Sepon Basin, Vilabouly District, Savannakhet Province. This research focuses mainly on technical development of open pit gold mine with three objectives. First, to construct the geological block model which provides the basis for resource/reserve estimation, and will be used as inputs in the stage of mine optimization, mine design and operation, Second, to develop a financial model using Discounted Cash Flow (DCF), and the criteria of Net present Value (NPV), the Internal Rate of Return (IRR), and the Weight Average Cost of Capital (WACC). Third, to address the environmental and social impacts from mine operation and proposed some mitigation guidelines. The geological model with 3,218 assays data collected from collected from 54 drillholes is prepared in MineSight input format. The geological volume extends 700 meters in x direction (Easting), 500 meters in y direction (Northing) and 250 meters in z direction (thickness).The results from resources estimation gives the geological resource of 34.87 million tonnes with the respective average ore grade at 0.58 ppm. The geological block model is constructed with the block dimension of 12.5m. x 12.5m. x 5m bringing to the total of 17,421 blocks. The ultimate pit is designed using Lerchs-Grossmann algorithm providing the mine mineable reserve at 2.44 million tonnes at the average grade of 1.53 ppm. This mine is schedule with 4 years of mine life at the average annual production capacity of 600,000 tonnes. For material handling, it requires five trucks, one wheel loader and one excavator to handle the production of 160 t/hr. In terms of financial estimations, the NPV is calculated at 1.93 million USD, and IRR of 22 percent that is higher than WACC of 12.6 percent. For the environmental mitigations, it is suggested to follow the Lao National Environmental Standard to control the noise, dust, vibration and some recommendation for blasting practice. In summary, this gold mine project is proven feasible taking into consideration of technical, financial and environmental issue.
DOI: 10.14457/cu.the.2015.205
title: PLACEMENT OF INFLOW CONTROL VALVES FOR HORIZONTAL OIL WELL IN HETEROGENEOUS RESERVOIRS

description: Horizontal well yields several advantages compared to vertical well. Increasing exposure area is probably one of the first reasons to drill this type of well. However, when horizontal well is implemented in highly heterogeneous reservoir; water encroachment from underneath aquifer will permeate through high permeability zone, causing locally high water production. Installation of Inflow Control Valve (ICV) in particular sections can mitigate this early water production. Configuring horizontal well with proper operating parameters could yield benefits on both increment of oil recovery and reduction of produced water. In this study, the heel side of horizontal section should be placed at low permeability region to compensate water encroachment due to friction loss inside production string. After placing horizontal well location on top layer of reservoir to increase as much as possible the drainage volume and fixing appropriate total liquid production rate, the well is configured to identify segment partitioning method, number of ICV, and pre-set water cut, respectively. From simulation results, partitioning well segment by using well contact transmissibility with the highest number of ICV segments yields benefit on both oil and water productions. Moreover, pre-set watercut of each valve should be configured to terminate the operation at 90 to 95 percent of the maximum watercut value. By using the best ICV configuration, increment of 11% total oil produced can be obtained. At the same time, this configuration can reduce water production by 16%. In case of reservoir containing small value of heterogeneity, benefits from ICV installation is not as well-pronounced as reservoir with high heterogeneity as water encroachment problem is not severe in case of low heterogeneous reservoir.
DOI: 10.14457/cu.the.2015.206
title: Growth and characterization of GaSb and InSb quantum dots on cross-hatch patterns

description: This thesis is dedicated to study guiding effect of strain from cross-hatch pattern (CHP) to GaSb quantum dot (QD) and InSb QD nucleation. A 6-nm GaAs spacer on 30-nm In0.17Ga0.83As CHP on GaAs (001) substrate, fabricated by molecular beam epitaxy (MBE), is used as the CHP guiding template. Two different growth techniques-Conventional and Migration Enhance Epitaxy (MEE)-are performed for the antimonide QDs growth. The morphology of self-aligned GaSb and InSb QDs on CHP are characterized by atomic force microscopy (AFM). The GaSb QDs grown by MEE shows the obvious nucleation on the CHP ridges compares to the QDs grown by MBE, which QDs distribute all over the areas. The average height of GaSb QDs, formed on the CHP ridges, grown by MEE is almost doubled that of GaSb QDs grown by MBE. Moreover, a simple descriptive model is proposed to demonstrate the GaSb QD formation mechanism on CHP ridges. In contrast, the compressive strain from CHP does not affect the nucleation of InSb QDs on the ridges because the InSb QDs prefer to nucleate on the flat areas where the tensile strain exists. The photoluminescence (PL) spectra from side-emission of GaSb QDs grown by MEE shows the energy peaks at ~0.73-0.75 eV and ~1.14 eV. These two peaks correspond to carrier transitions between GaSb QDs and InGaAs and GaAs, respectively.
DOI: 10.14457/cu.the.2015.207
title: Effect of molybdenum content on heat treatment behavior of multi-alloyed white cast iron

description: Multi-alloyed white cast iron contains several kinds of carbide forming elements namely V, Cr, Mo and W to form their own carbides during solidification. In such alloying elements, Mo is very useful one which not only forms eutectic carbide but also dissolves into matrix to improve the characteristics of heat treatment. In order to investigate the effect of Mo content on the heat treatment behavior, the multi-alloyed white cast iron varying Mo content from nil to 7.66 mass% were prepared. After annealing, test pieces in disk shape were austenitized at 1,373K for 3.6 ks in vacuum furnace and then, hardened by liquid nitrogen. The hardened specimens were tempered at various temperatures between 673 and 873K for 12 ks. As Mo content of the specimen increased, the macro- and micro-hardness in as-hardened state increased progressively. In tempered state, hardness curves showed secondary hardening, i.e. with increasing of tempering temperature; the hardness rose first to the maximum value and then decreased. The reason why secondary hardening takes place is mainly due to the precipitation of special carbides from martensite by carbide reaction and the martensite transformation from the rest of austenite during post cooling. The maximum tempered hardness (HTmax) was obtained at 798K tempering, regardless of Mo content of specimens and the highest HTmax was 946 HV30 in specimen with 4.98%Mo. Volume fraction of retained austenite (Vγ) in as-hardened state decreases gradually with an increase in Mo content. In tempered state, the Vγ began to decrease remarkably as the tempering temperature got over 748K in all the specimens. The Vγ values at HTmax were less than 10% and the Vγ at HTmax decreased proportionally from 10% to 2% as the Mo content is increased.
DOI: 10.14457/cu.the.2015.208
title: Semi-automated well interventions and units allocation scheduler

description: Oil and gas production operational activities are increasing due to number of smaller fields with same production target. In Gulf of Thailand, oil and gas formations are small pockets, thus the activity levels are relatively high leading to more time and complicated operation sequence scheduling. The proposed Linear programming (LP) optimization model with binary variable is constructed of CPLEX optimizer program. This study aims to develop LP model to optimize unit scheduling semi-automatically and apply it to well intervention and unit operation sequence optimization of an oil and gas production field in Thailand. Electric line unit, slick line unit and well interventions done by these units are involved. Well interventions duration and units mobilization time are also included. Solving binary variable allows unit and job sequences shuffle to yield minimum solution which the model’s constraints are satisfied. Multiple model inputs are changed to validate the model. Total unit utilization time and total finished time minimization are scheduler’s most suitable objective function. Both number of event point and due date constraints affect model’s search space which may change the solution of scheduler. The scheduler also reduces time usage and complexity resulting in more efficient and better management of units operation of oil and gas production field.The validated optimization model is applied to field well intervention operation case. The scheduler has identified optimization opportunity of selected field case. Furthermore, several sensitivity analysis cases of operational options and operation uncertainties are performed.
DOI: 10.14457/cu.the.2015.209
title: SIMULATION AND PROCESS DESIGN FOR HYDROGEN PRODUCTION USING SORPTION-ENHANCED CHEMICAL LOOPING REFORMING OF METHANE

description: This research focuses on the investigation and improvement of sorption enhanced chemical-looping reforming process for hydrogen production. Methane, CaO and NiO were employed as a raw material, CO2 adsorbent, and oxidizing agent, respectively. In this work, the effects of reforming temperature, steam flow rate, and solid circulation rate on the process performances of sorption enhanced chemical-looping reforming process were firstly studied. Subsequently, its process performances at the optimal condition were compared with those from other two hydrogen production processes i.e., steam reforming and sorption enhanced steam reforming processes. It was found that the sorption enhanced chemical-looping reforming process showed the best performance. In addition, the feasibility of adiabatic operation of reactors for sorption enhanced chemical-looping reforming process was considered. It was found that all reactors of this process could be adiabatically operated by adjusting some parameters such as steam feed temperature, air feed temperature, solid ratio from calcination reactor to air reactor, and solid ratio from air reactor to calcination reactor. Moreover, the influence of CO2 content in feed stream on an adiabatic operation of sorption enhanced chemical-looping reforming process was investigated. Higher in CO2 content in feed stream exhibited the negative effects on the SECLR process that was operated adiabatically such as less H2 productivity and H2 purity. For the reactors of sorption enhanced chemical-looping reforming process, their preliminary design was also taken into account. It could be reasonably indicated that the reactors of SECLR process would be 3-connected fluidized bed reactor which reforming and calcination reactors were carried out in bubbling regime while air reactor was operated in fast fluidization regime. The difference in diameter of each reactor depending on its operating regime was observed.
DOI: 10.14457/cu.the.2015.210
title: Separation of neodymium from rare earth metals via hollow fiber supported liquid membrane

description: This study investigated the separation of neodymium ions from mixed rare earth via hollow fiber supported liquid membrane (HFSLM). The effects of type and concentration of extractant/stripping agent i.e. PC88A/H2SO4 and Cyanex 272:TOPO/HNO3, pH in feed solution, flow patterns of feed and stripping solutions as well as flow rates of feed and stripping solutions were investigated. The optimum condition was identified and reported: PC88A/ H2SO4 hybrid at 4.5 pH of feed solution, 0.5 M PC88A as extractant, 1M H2SO4 in stripping solution and operating temperature of 303 K. For synergistic extractants, 0.5:0.5M/M of Cyanex 272:TOPO, 4 M HNO3 as stripping solution at 4.5 pH of feed solution and temperature of 303 K were reported. Flow rate of feed and stripping solution of 100 mL/min was found to be the most practical setup. In conjunction with the experimental work, a new model on convection, diffusion, reaction and accumulation was developed in order to predict the concentration of neodymium ions via HFSLM. Upon verification, the hypothetical concentration of neodymium ions in feed and stripping solutions aligned closely with the experimental results. Average standard deviations for extraction and stripping predictions were 1.9% and 1.2%, respectively. This robust model with its high accuracy provides a greater understanding of transport mechanism across the feed to the stripping solution; a design scale-up for industrial application could prove useful.
DOI: 10.14457/cu.the.2015.211
title: Development of novel Bubble Column Reactor (BCR) for iron removal in groundwater

description: Iron in groundwater mostly in ferrous form with the high concentration is likely the most common water problem. Bubble Column Reactor (BCR) or Airlift Reactor (ALR) is one of the best multiphase contactors that provides many advantages in aeration and oxidation. However, several inadequate points are still required to refin for improving its efficiency. This work aimed to optimize the novel reactor for improving the aeration process and ferrous iron oxidation. Novel Bubble Column Reactor (Novel BCR) that has a cross sectional dimension of 0.4m×0.5m (140L capacity), was developed by inserting the vertical baffle to create a liquid recirculation from a riser to downcomer compartment, and installing horizontal baffles in a riser to increase the bubble retention time and improve the air bubble distribution. Bubble hydrodynamic parameter was studied for well understand the internal mechanism in the reactor. The optimum level of Novel BCR was obtained from the condition that provided overall maximum liquid mass transfer coefficient (KLa) after variation of various parameters. Main influenced factors of Novel BCR performance are the position of recirculation area (Yr), amount of baffle (Nb), settling area on baffle (AS), and baffle angle (α) with respective value: 10cm, 3 baffles, 90cm2, and 50° at 0.45 of optimum downcomer-to-riser ratio. Novel BCR improved the oxygen transfer in terms of KLa coefficient from 50% to 97% compared to conventional BCR and 6% to 28% compared to ALR in the ranges of gas flow rate of 4 - 16 LPM. Moreover, the study of ferrous iron oxidation in this novel reactor was conducted by varying initial concentrations of ferrous iron (5 to 50 mg/L) and gas flow rates (2 to 10 LPM) as a semi-batch reactor. The oxidation is faster at lower initial concentration of ferrous iron and the operation in Novel BCR exhibited greater ferrous oxidation than conventional BCR. In the studied gas flow rates, increasing gas flow rate improved conversion yield of ferrous iron.
DOI: 10.14457/cu.the.2015.212
title: Improving supplier selection and evaluation process in processed chicken food factory

description: Supplier selection is a complex problem and a strategic activity of a purchasing department in a supply chain. Suppliers are not selected based only on price but also selected based on multi-criteria both qualitative and quantitative criterions. A trade-off between these tangible and intangible factors finally provides the best supplier who offers the best deal among others. The study incorporates AHP in selecting the best supplier. This approach provides an explicit way of criteria evaluation to select the right supplier, depending on its importance. For this study, an AHP supplier selection model is formulated and applied to the real case study for frozen chicken-food manufacturing company in Thailand. Using the AHP-based multi-criteria decision model via scoring suppliers performance reduces time and effort in supplier selection as well as improves decision making process of solving the supplier selection problem.
DOI: 10.14457/cu.the.2015.213
title: Development of an economical walk-through radiation monitoring system

description: This research aimed to develop an economical Walk-through Radiation Monitoring System (WRMS) for preventing the radioactive materials from unauthorized movement and also illegal trafficking. The developed monitoring system was constructed by mainly using of local materials and inexpensive devices. Two 3”x3” NaI(Tl) scintillation detectors were employed for gamma detection and installed in a pair of PVC pillar gate with 90cm x 200cm frame size. The system structure composed of: dual detector pulse summing counter, ratemeter, bi-directional occupancy sensor, radiation alarm warning circuit, and video surveillance recording from CCTV system. The developed system was tested by a person carry a 1 μCi of Cs-137 source walk-through the gate with approximately walking speed of 1.4 m/s. It was found that the system could detect the source and worked properly. With this level of sensitivity, it could be applied for low radiation level source security and also increasing safety control efficiency of the radiation safety officer in laboratory.
DOI: 10.14457/cu.the.2015.214
title: Impurity removal from tin concentrate of Lao-Korea tin mine, Khammuan province, Lao PDR

description: A process for the removal of impurities from tin concentrate of Lao-Korea tin mine has been developed. Wet Scrubbing of tin concentrate grading 23.23% Sn followed by wet high-intensity magnetic separation is a successful method of separation. The scrubbed and non-magnetic fraction obtained has been upgraded to be 60.00-61.51% Sn with 89.97-93.38% recovery. Weak acid scrubbing has also been tried and this can help reducing the scrubbing time. Screening of the scrubbed and non-magnetic fraction grading 60.90% Sn using 212 micron screen to classify this fraction into 2 size fractions (+212 micron and -212 micron size fractions) has been done. It has been found that the +212 micron size fraction has a higher grade of 70.32% Sn which can be a saleable tin concentrate. Whereas the -212 micron size fraction having a lower grade of 50.87% Sn needs to be further upgraded. Higher-tension separation is recommended to treat this -212 micron size fraction hoping to separate the non-conductor impurities of zircon and quartz from the conductor cassiterite with the saleable grade of about 70% Sn.