cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.14457/cu.the.2006.1498
title: Epoxide ring opening by ZSM-5 catalysts

description: A series of H-ZSM-5 zeolites with Si/AI ratios in arrange of 10-50 were tested in the epoxide ring opening catalysis. All ZSM-5 catalysts were synthesized by hydrothermal method and characterized by XRD, SEM/EDX, [subscript 27] AI MAS NMR and nitrogen adsorption (BET), to link catalyst properties to catalytic behavior. The catalysis of epoxide ring opening was carried out in the heterogeneous system. H-ZSM-5 with high Si/AI of 36 was an effective catalyst for styrene oxide ring opening, which gave the high yield of 2-methoxy-2-phenylethanol of higher 89% with a good selectivity at the reaction temperature of 70ํc for 3 h. This optimum condition was further applied for other epoxides: 1-dodecene oxide and cyclohexene oxide. The catalytic reaction of epoxide ring opening over ZSM-5 catalyst could be proceeded and gave the relatively high quantity in product yield of alcohol derivatives. In addition, the reused catalyst with regeneration by calcined at 540ํc for 5 h was studied for the reaction of epoxide ring opening. The result shows a high efficiency with the high yield of desired product and selectivity to 2-methoxy-2-phenylethanol, after testing for four cycles.
DOI: 10.14457/cu.the.2006.1499
title: W-distances on a metric space

description: In this thesis, we investigate properties of w-distances on metric spaces. We give a relationship among w-distances, metrics, metric-preserving functions, and topological properties. We introduce the notion of Cauchy w-distances and state some of their properties.
DOI: 10.14457/cu.the.2006.1500
title: Self-assembled quantum dot molecules by molecular beam epitaxy and their potential applications

description: The aim of this thesis is to investigate the formation mechanism of nanostructures, especially lateral quantum dot molecules (QDMs) using partial-capping-and-regrowth technique with both solid-source molecular beam epitaxy (MBE) and gas-source MBE. The physical and optical properties of all nanostructures are measured by ex-situ atomic force microscopy (AFM) and photoluminescence (PL). With solid-source MBE under an As[subscript4] ambient, as-grown quantum dots (QDs) change to a camel-like nanostructure after being partially overgrown with GaAs (partial capping). When additional InAs is deposited (regrowth), QDMs with 10-12 dots per QDM are obtained. During thepartial GaAs capping of InAs QDs, if the capping temperature is varied, the length of the nanopropellers can be controlled. The lowering of the capping temperature leads to smaller dot per QDM after regrowth process. With gas-source MBE where As[subscript2] is generated by thermally cracked arsine, as-grown QDs are transformed into quantum rings after partial capping with GaAs. After the regrowth process, QD pairs or double QDs are obtained. At higher regrowth temperature, QD rings with 5-7 dots per ring are formed. Surface morphologies of self-assembled (Ga) InAs nanostructures and QDMs grown by partial-capping-and-regrowth technique using gas-source MBE and solid-source MBE are compared. The difference in the migration length of group III adatoms under different arsenic species, As[subscript2] in gas-source MBE and As[subscript4] in solid-source MBE, is the origin of respective outcomes of nanostructures and QDMs.
DOI: 10.14457/cu.the.2006.1501
title: Analysis of morphometric and genetic variation of small dwarf honey bees Apis andreniformis Smith, 1858 in Thailand

description: Small dwarf honey bee, Apis andreniformis, is one of native Thai honey bees. Less data on morphometric and genetic variation of this species have been reported. In this investigaion, thirty colonies of A. andreniformis were collected for morphometric analysis and 37 colonies were collected for genetic analysis. For morphometric analysis, 24 characters of worker bees were measured and analysis. By using colony means for the 1st factor analysis, 20 out of 24 morphometric characters were selected as new variable. For the 2nd analysis, 20 morphometric characters could be grouped into 4 new factors. Due to graph plotting of factor scores, bees from Thailand and from Tenom, Malaysia belong into one group. In addition, a dendrogram generated from cluster analysis supports that bees from Thailand and Tenom, Malyaysia are clumped into one group. However, result on linear regression analysis of factor scores against latitude and longitude shows clinal patterns in morphometric characters of A. andreniformis in Thailand. The body size of bees from the south to the north increase but decreased in bees from the west to the east. Genetic variation was determined into 2 means. First, genetic variation was analyzed by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). After amplification of cytochrome oxidase subunit b (cytb), products of 520 bp were restricted by DraI and AluI. Genetic variation was observed. Six haplotypes were found after AluI digestion while 3 haplotypes were found after DraI digestion. Second, PCR products amplified by cytb were sequenced. Based on nucleoide analysis, DNA polymorphism among bees from mainland of Thailand is lower that from Phuket Island and Chiang Mai. Phylogenetic trees were constructed by Neighbor-joining and UPGMA programs. Two different groups of A andreniformis of Thailand are obtained from both trees. Bees in group A are from mainland while bees in group B are from Phuket Island and Chiang Mai.
DOI: 10.14457/cu.the.2006.1502
title: Effects of microwave sintering and zirconia addition on microstructure and optical transmittance of alumina ceramic

description: To study the effect of microwave sintering comparing with conventional sintering and the effect of zirconia addition on microstructure and optical transmittance of transparent alumina ceramic. The experiment was concentrated on increasing the transmittance of alumina ceramic by reducing grain size of alumina to submicron level. Alumina powder was used as raw material. Green samples were prepared by biaxial hydraulic pressing with 20 MPa and followed by cold isostatic press (CIP) of 200 MPa. Sintering was performed at temperatures ranging from 1300 to 1500 ํC for 2 hr followed by hot isostatic press (HIP) at temperatures ranging from 1250 to 1300 ํC for 0.5, 1 and 2 hr with pressure of 150 MPa under Ar atmosphere. Microwave sintering resulted in the fast processing time and accelerated densification to sinter alumina ceramic, but did not show the higher density than that of conventional sintering. The transmittance of microwave sintered specimens was lower than that of conventional one because of the larger grain size distribution. The optimum HIP condition selected from the results was 1300 ํC for 0.5 hr with a heating rate of 10 ํC/min. Zero, 0.2, and 0.4 wt% of zirconia were added to alumina powder together with 0.03 wt% of MgO. Zirconia addition inhibited grain growth of alumina grain. However, it also disturbed densification. The sintering temperature of alumina with zirconia to attain the same high density shifted to higher temperature than alumina with zirconia composition. Then the grain size of the full density specimen with zerconium was a little larger than that without zirconia. As a result, better optical transmittance was not attained from the composition with zirconia.
DOI: 10.14457/cu.the.2006.1503
title: Effect of nanoclay compositions on biodegradability of methyl cellulose/montmorillonite nanocomposites

description: This research aims to develop methyl cellulose (MC), a biodegradable polymer by using two methods. The first method is the use of montmorillonite (MMT) as nanoreinforcement for preparation of nanocomposites. The second one is the use of glutaraldehyde (GA) to promote covalent linkages between MC polymer chains. In comparison of the rendered films from two methods with pure MC, some characterizations such as the analysis of morphology, thermal properties, dynamic mechanical properties, tensile properties, moisture absorption, water solubility, and biodegradability were determined. MC/MMT nanocomposite films prepared by MMT suspension was exfoliated nanocomposite which was comfirmed by XRD and TEM results. In the crosslinked system, the FTIR spectra revealed the crosslink density between MC and GA. This value was proportional to the GA content, and optimum GA content was 4.5wt%. In addition, MC prepared from both methods was capable to enhance different properties. The MC/MMT nanocomposites could significantly improve tensile properties (65% for tensile modulus and 35% for tensile strength), while MC crosslinked film could outstandingly increase thermal properties (15% for T[subscript g]) and water solubility properties. The crosslinkage technique had more potential to hinder the biodegradation process. In 6 weeks, the CO emission of crosslinked films was reduced around 80% in comparison with that of pure MC.
DOI: 10.14457/cu.the.2006.1504
title: Development of nanostructure membrane from regenerated bacterial cellulose

description: In this research study, bacterial cellulose (BC) and alginate were used as raw materials for the frabrication of a new regenerated cellulose membrane. The environmental friendly procedure for regenerated bacterial cellulose (RBC) was developed. The optimum conditions involved swelling BC in 4% wt NaOH/ 3% wt urea solution, followed by freeze thaw process and blending with alginate at various rations. Supercritical CO[subscript 2] drying method was then applied for porous preparation of the membrane. Afterward, the fabricated membranes were characterized for nonstructure and physical properties. The mechanical properties of the pure RBC membrane were better than the blend membranes. However, the water vapor permeability and the percent water absorption of the pure RBC membrane were lower. The tensile strength, the elongation at break and the percent water absorption of the pure RBC membrane were 4.32 MPa, 35.20% and 49.67%, respectively. The water vapor transmission rate of the RBC was 2,504 g/m[superscript 2] day and its pore size was 1.26 nm. The RBC blend membrane with 20% wt alginate exhibited the most orderly alignment of fibers on its surface with the tensile strength, the elongation at break and the percent water absorption at 3.38 MPa, 31.6% and 52.25%, respectively. The water vapor transmission rate was 5,609 g/m[superscript 2] day and the pore size was 1.06nm.
DOI: 10.14457/cu.the.2006.1505
title: Diterpenoids from the roots of Croton oblongifolius Roxb.

description: The objective of this study was to search for bioactive compounds from the roots of Croton oblongifolius. The dichlomethane crude extract of the roots of C. oblongifolius was purified by chromatographic techniques to afford two new compounds, 19,20-dimethyl-15,16-epoxy-3,13(16),14-clerodatriene-17,18-oate-12-one and methyl-15,16-epoxy-3,13(16),14- clerodatriene-18,19-olide-17-oate and seven known compounds namely levatin, crovatin, nasimalun A, nasimalun B, 15 hydroxy-cis-ent-cleroda-3,13(E)-diene, patchoulenone and (-)-hardwickiic acid. The chemical structures of all isolated compounds were established on the basis of chemical and spectroscopic methods. The isolated compounds were also subjected to bioactivity test. Patchoulenone exhibited cytotoxicity against P388 cell line with IC[subscript 50] value of 1.06 [microgram]/ml. 15 Hydroxy-cis-ent-cleroda-3, 13(E)-diene, nasimalun B and methyl-15,16-epoxy-3,13(16),14- clerodatriene-18,19-olide-17-oate showed weak cytotoxicity against the T47D cell line with IC[subscript 50] value of 17.0,13.0,and 10.0 [microgram]/ml, respectively.
DOI: 10.14457/cu.the.2006.1506
title: Analysis of permeability of low density polyethylene/clay nanocomposite films

description: The goals of this research were two folds, (i) to study the effects of loading of organoclay and compatibilizer on the permeability of LDPE/PE-g-MA/Org-MMT nanocomposite films, and (ii) to verify the applicability of the modified Nielsen model on prediction of permeability LDPE/PE-g-MA/Org-MIMT nanocomposite films. The LDPE/PE-g-MA/Org-MMT nanocomposites were prepared in the twin screw extruder in three-step mixing procedure and the blown into films. Gallery spacing between clay platelets of the Org-MMT and nanocomposite films were measured by X-ray diffraction. Transmission Electron Microscope (TEM) was used to study the distribution of clays in nanocomposite films. The Oxygen Transmission Rate (OTR) of the nanocomposite films were measured by the Oxygen Permeation Analyzer. The experimental permeability data were fitted by the modified Nielsen model. The experimental results showed that the nanocomposite films of LDPE with Org-MMT and PE-g-MA as compatibilizer having lower oxygen permeability properties than pure LDPE film can be obtained by melt mixing. The obtained LDPE/PE-g-MA/Org-MMT nanocomposite films were mainly the intercalated type. The oxygen gas permeability was reduced by about 50% at 3.14-5.09 wt% inorganic clay loading. The transparency of nanocomposite films slightly decreased with increasing clay content. The 9 wt% PE-g-MA was the optimum loading found. The modified Nielsen model can be used to predict the relative permeability of nanocomposite films providing that the aspect ratio, orientation angle, and volume fraction of inorganic clay could be found accurately.
DOI: 10.14457/cu.the.2006.1507
title: Systhesis of polyester containing p-alkoxycinnamate

description: This work involved the synthesis of three polymers containing UV absorptive chromphore. The first two monomers; 1,2-(bis(4-(2-carboxyvinyl)phenoxy))ethane (M2) and 1,12-(bis(4-(2-carboxyvinyl)phenoxy))dodecane (M12) were synthesized. Condensation polymerization between M2 or M12 and poly(ethylene glycol)200 (PEG200) or poly(ethylene glycol)400 (PEG400) yielded poly(1,2-(bis(4-(2-carboxyviny)phenoxy))ethane)-co-(poly(ethylene glycol)200)), poly((1,2-(bis(4-2-carboxyvinyl)phenoxy))ethane)-co-(poly(ethylene glycol)400)) and poly((1,12-(bis(4-(2-carboxyvinyl) phenoxy))dodecane)-co-(poly(ethylene glycol)400)). The averaged molecular weights of all three polymers were in the range of 2100-2600 Da. Absorption profiles of all synthesized polymers indicated UVB absorption property. The M2-PEG400 copolymer, a yellowish liquid, showed good solubility in various organic solvents. In addition, poly((1,2-(bis(4-(2-carboxyvinyl)phenoxy))ethane)-co-(poly(ethylene glycol)400)) and poly((1,12-(bis(4-(2-carboxyvinyl)phenoxy))dodecane)-co-(poly(ethylene glycol)400)) could be prepared as nano/microparticles with an average size of 500 nm and 3 [micro]m respectively, through solvent displacement technique.
DOI: 10.14457/cu.the.2006.1508
title: Bioactive compounds from the stems and stem bark of Feroniella lucida

description: In phytochemical investigation for bioactive compounds from Thai medicinal plants in the family Rutaceae, dichlormethane crude extract from the stems of Feroniella lucida was selected for isolation, purification and structure elucidation. The chromatographic separation of dichloromethane crude extract led to the isolation of a novel furanocoumarin, feroniellin A (7), along with eight known coumarins, psoralen (1), bergapten (2), isopimpinellin (3), anisolactone (4), 2',3'-epoxyanisolactone (5), marmesin (6), feroniellin B (9), and feroniellin C (8). On the other hand, the dried stem bark of this plant was macerated in dichloromethane. This extract was isolated to afford seven triterpenoids. They were three new triterpenoids: feroniellide C (13), feroniellide D (15), and feroniellide E (16) and four known triterpenoids; N-methyl anthranilic ester triterpenoid (10-12) and isovaleric acid ester triterpenoid (14). The structures of all isolated compounds were elucidated by spectroscopic methods as well as comparison with previous literature data. All of the isolated compounds were tested for inhibitory activity of acetylcholinesterase and cytotoxicity on HeLa and KB cell lines. Compounds 3, 6, 7, 8, 9, 11, and 12 showed inhibitory activity of acetylcholinesterase with MIC value of 0.500 mg/mL. In addition, compound 14 exhibited significant cytotoxicity activity against HeLa cell line with IC[subscript 50] value of 8.2 [micro]g/mL, while compounds 10, 15 and 16 also showed potent cytotoxicity against KB cell line with IC[subscript 50] value of 5.2, 4.1 and 3.4 [micro]g/mL, respectively.
DOI: 10.14457/cu.the.2006.1509
title: An analysis technique to increase testability of class-component

description: Testing software is made easier when testability is high. In general, increasing testability allows faults to be detected more efficiently. Component-based software is often constructed from third party software components. When this is done, the reused components must be retested in the new environment to ensure that they integrate correctly into the new context. Therefore, it is helpful to increase a component's testability before it is reused. Also, it is helpful to measure a component's testability to indicate the difficult of revealing faults. Some information about components is needed to in crease and measure component's testabilit, such as information gotten through program analysis. A crucial property of reused software components is that the source is not available, making program analysis significantly more difficult. This thesis addresses this problem by performing program analysis at bytecode level. This bycote analysis technique increases and measures components testability without requiring access to the source code. A component's bytecode is analyzed to gather control and data flow information, which is then used to obtain definition and use information of method and class variable of component. Then, the definition and use information is used to increase component testability during component integration, and measure component testability for estimating the difficulty of testing. We have implemented the technique and applied it on some sampled component. Experimental results reveal that fault detection ability can be increased by using our increasing testability process. Also, the proposed testability measurement is appropriate in indicating component testability.
DOI: 10.3886/e111421
title: Patient Cost Sharing and Healthcare Utilization in Early Childhood: Evidence from a Regression Discontinuity Design

description: This paper estimates the price elasticity of healthcare utilization in early childhood. We employ a regression discontinuity design by exploiting a subsidy that reduces patient cost-sharing for children aged under 3 in Taiwan. Using longitudinal medical claims of over 410,000 children, we find a modest price elasticity of outpatient expenditure (e.g. -0.10 for regular outpatient care). Furthermore, increased cost-sharing at age 3 largely decreases the chance of visiting high-intensity healthcare providers (e.g. teaching hospitals) for minor illnesses. In contrast, children’s utilization of inpatient care is price insensitive, providing a rationale for full inpatient care coverage to children.
description: Not applicable
description: Response Rates: We use administrative records data.
description: Presence of Common Scales: Not applicable
description: other;
description: All children under age 4 in Taiwan. Smallest Geographic Unit: County
description: We use administrative records data.
DOI: 10.3886/e111421v1
title: Patient Cost Sharing and Healthcare Utilization in Early Childhood: Evidence from a Regression Discontinuity Design

description: This paper estimates the price elasticity of healthcare utilization in early childhood. We employ a regression discontinuity design by exploiting a subsidy that reduces patient cost-sharing for children aged under 3 in Taiwan. Using longitudinal medical claims of over 410,000 children, we find a modest price elasticity of outpatient expenditure (e.g. -0.10 for regular outpatient care). Furthermore, increased cost-sharing at age 3 largely decreases the chance of visiting high-intensity healthcare providers (e.g. teaching hospitals) for minor illnesses. In contrast, children’s utilization of inpatient care is price insensitive, providing a rationale for full inpatient care coverage to children.
description: Not applicable
description: Response Rates: We use administrative records data.
description: Presence of Common Scales: Not applicable
description: other;
description: All children under age 4 in Taiwan. Smallest Geographic Unit: County
description: We use administrative records data.
DOI: 10.3886/e115107
title: Data and Code for: Criminal Deterrence when there are Offsetting Risks: Traffic Cameras, Vehicular Accidents, and Public Safety

description: Numerous cities have enacted electronic monitoring programs at traffic intersections in an effort to reduce the high number of vehicle accidents. The rationale is that the higher expected fines for running a red light will induce drivers to stop and lead to fewer cross-road collisions. However, the cameras also incentivize drivers to accept a greater accident risk from stopping. We evaluate the termination of a monitoring program via a voter referendum using 12 years of geocoded police accident data. We find that the cameras changed the composition of accidents, but no evidence of a reduction in total accidents or injuries.
DOI: 10.3886/e115107v1
title: Data and Code for: Criminal Deterrence when there are Offsetting Risks: Traffic Cameras, Vehicular Accidents, and Public Safety

description: Numerous cities have enacted electronic monitoring programs at traffic intersections in an effort to reduce the high number of vehicle accidents. The rationale is that the higher expected fines for running a red light will induce drivers to stop and lead to fewer cross-road collisions. However, the cameras also incentivize drivers to accept a greater accident risk from stopping. We evaluate the termination of a monitoring program via a voter referendum using 12 years of geocoded police accident data. We find that the cameras changed the composition of accidents, but no evidence of a reduction in total accidents or injuries.
DOI: 10.3886/e115405
title: Data and Code for: Price-Linked Subsidies and Imperfect Competition in Health Insurance

description: Policymakers subsidizing health insurance often face uncertainty about future market prices. We study the implications of one policy response: linking subsidies to prices, to target a given post-subsidy premium. We show that these price-linked subsidies weaken competition, raising prices for the government and/or consumers. However, price-linking also ties subsidies to health care cost shocks, which may be desirable. Evaluating this tradeoff empirically, using a model estimated with Massachusetts insurance exchange data, we find that price-linking increases prices 1-6%, and much morein less competitive markets. For cost uncertainty reasonable in a mature market, these losses outweigh the benefits of price-linking.
DOI: 10.3886/e115405v1
title: Data and Code for: Price-Linked Subsidies and Imperfect Competition in Health Insurance

description: Policymakers subsidizing health insurance often face uncertainty about future market prices. We study the implications of one policy response: linking subsidies to prices, to target a given post-subsidy premium. We show that these price-linked subsidies weaken competition, raising prices for the government and/or consumers. However, price-linking also ties subsidies to health care cost shocks, which may be desirable. Evaluating this tradeoff empirically, using a model estimated with Massachusetts insurance exchange data, we find that price-linking increases prices 1-6%, and much morein less competitive markets. For cost uncertainty reasonable in a mature market, these losses outweigh the benefits of price-linking.