cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.14457/cu.the.2011.116
title: The roles of HIV-1 specific interferon gamma (IFN-gamma) producing CD8+T lymphocyte responses and HLA class I alleles on viral escape and viral control in HIV-1 infected Thai individuals

description: The role of CD8+ T cells and HLA class I in viral escape and viral control has not been well characterized in clade CRF01_AE and Asian ethnics. 240 naïve HIV-1 infected Thai individuals were screened by IFN-γ ELISpot assay for HIV-1 specific CD8+ T cell responses with a set of 413 overlapping peptides (OLPs) of HIV-1 proteome. Novel epitopes were identified by bioinformatics analysis and were further characterized by HLA restriction and fine epitope mapping. The association of epitopes and/or HLA alleles with low plasma HIV-RNA levels and/or viral escape was analyzed using non parametric statistical analysis. We found that HLA-B*1302 and HLA-A*2410 after exclude other known protective alleles were associated with low plasma HIV-RNA level (p = 0.0024 and p = 0.0062, respectively). The four most common CD8+ T cell responded HIV-1 targets included Pol (91%), Gag (87%), Env (83%) and Nef (78%). As reported in other ethnic and subtypes, Gag-specific CD8+ T cell response was found associated with low plasma HIV-RNA level whereas Env-specific CD8+ T cell response was associated with high plasma HIV-RNA level. From 195 HIV-1 CRF01_AE infected Thais, 33 OLPs as potential novel epitopes were identified. A novel immunodominant (29% response rate) restricted by HLA-Cw*0102: YI9 (in Gag-p24) which was associated with viral escape. Mutations at P2 (S278X), P4 (V280X) and P5 (S281G) impaired the ELISpot responses, however the P2 anchor S278K mutation had the highest negative impact (p = 0.0002). We also found two viral control epitopes, the first one is RI10 (HIV-protease, previously described in HIV-1 B clade as -B*13 restricted) was found restricted by HLA-A*0203 in Thais. Interestingly, HLA-A*0203+ve patients with RI10 responders had a significantly lower plasma HIV-RNA level than non-responders (p = 0.0167). Moreover, mutation in this RI10 had resulted to immune escape, but it was remained associated with low plasma HIV-RNA level, this may be due to compromising on their viral fitness. The other one is the known HLA-A*1101 epitope, AK11 (in Gag-p24), there was no significant mutation of viruses found in patients expressing A*1101. In conclusions: HLA-B*1302 and HLA*A2410 were associated with low plasma HIV-RNA level. Pol, Gag, Env and Nef are four most common HIV targets of CD8 T cells, however; only HIV-1 Gag was found associated with low plasma HIV-RNA level. Three CD8 epitopes: YI9, RI10 and AK11 restricted by HLA-Cw*0102, -A*0203 and -A*1101, respectively; were characterized. RI10 and AK11, but not YI9, were associated with lower plasma HIV-RNA level that possibly to HIV viral control. Further characterization of the rest of possible novel epitopes is warranted.
DOI: 10.14457/cu.the.2011.117
title: Effects of flow pattern on CO₂ capture using potassium carbonate in circulating fluidzed bed

description: To investigate the effect of flow pattern/regime in fluidized bed/circulating fluidized bed on CO₂ capture from flue gas, released from a fossil fuel combustion process, at low temperature 60℃ using potassium carbonate supported on alumina (K₂CO₃/Al₂O₃) solid sorbent prepared by impregnation method. The semi-circulating fluidized riser made from glass has 0.025 m of inner diameter and 0.80 m of height. The flow pattern/regime was characterized by measuring pressure fluctuation in the riser. It can be divided into five different flow patterns/regimes including fixed bed, multiple bubbling, slugging, turbulent and fast fluidization as gas velocity increased. The fixed bed and multiple-bubbling bed could adsorb all CO₂ in flue gas (CO₂ removal fraction = 1). The slugging, turbulent and fast fluidization could not remove all CO₂ in flue gas. Maximum CO₂ removal fractions for slugging, turbulent and fast fluidization are 0.98, 0.94 and 0.72, respectively. However, the turbulent regime provides the best CO₂ capture capacity at about 90% of stoichiometic theoretical value. The CO₂ capture capacity for the multiple-bubbling and fast fluidization regimes are secondary with about 66-72% of stoichiometic theoretical value. The fixed bed and slugging regimes provide the poorest CO₂ capture capacity at about 53-60% of stoichiometic theoretical value. For K₂CO₃/Al₂O₃ solid sorbent, this solid sorbent was completely regenerated for temperature higher than 300℃ resulting in higher stability to maintain capacity.
DOI: 10.14457/cu.the.2011.119
title: Effects of Ni, CO and In on microstructures, electrical properties and mechanical properties of Sn-Cu solder alloy

description: Pb-containing solder alloys were widely used in electronic industries for decades but due to toxicity of Pb, worldwide restrictions were emerged to ban Pb usage in all electronic parts. Subsequently, several lead-free solder alloy compositions were developed. Sn-Ag-Cu alloy systems have been proposed to be amongst the first candidates. However, due to price fluctuation of Ag, many manufacturers are moving toward Sn-Cu solder alloys. Despite of lower cost, Sn-Cu solder alloys have inferior properties. In this research, we study the effects of Ni, Co and In additions to Sn-Cu solder alloy in order to improve its key properties for electronic applications. The result shows that addition of In lowers the melting point of Sn-Cu alloys to comparable value of that of Sn-3.0Ag-0.5Cu. The optimal amounts of Ni, Co and In additions result in improved hardness and shear strength by formation of intermetallic compounds that strengthen the soldered interface. The additions result in increased electrical resistivity. The Sn-Cu-Ni-Co-In solder alloys can maintain their shear strength after aging at 150oC for 1,000 hours. Sn-3.0Ag-0.5Cu shows 25.33% drop in its shear strength while Sn-Cu-Ni-Co-In alloys show only 3.82% drop. This is due to the uniformly distributed intermetallic compound which serves as dislocation obstacles and multiple sites for local stress concentration.
DOI: 10.14457/cu.the.2011.120
title: Effects of a Healthy Unit Guidance (HUG) program on work environments and health outcomes among nursing personnel

description: Nursing personnel are at a high risk of exposure to ergonomic risk factors, lead to development of work-related musculoskeletal disorders (WMSDs). Effective participatory ergonomic intervention is beneficial and has indicated that can prevent musculoskeletal disorders. The purpose of this quasi-experimental study was to evaluate effects of the Healthy Unit Guidance (HUG) program, a tailored participatory ergonomics intervention, on work environments and health outcomes among nursing personnel. The HUG program consisted of a multifaceted training with three workshops include establish management support, participant’s capacity strengthening, and evaluation work improvement achievement. The study was conducted at two tertiary care hospitals during May 2010 to June 2011. Of a total 90 participants, nursing personnel from the selected hospital were assigned in an intervention group (n=45), with those from another hospital used as a control group (n=45). Data collection was carried out by self-reported questionnaire at baseline, 3 months and 6 months after the completion of the intervention. Comparison of work environments and health outcomes scores between the two groups were analyzed using t-test, repeated measure analysis of variance as well as Mann-Whiney U test. The results showed that physical work environment among the intervention group was significantly decreased compared with the control group at 3 months (p &lt; .01), while there was not significantly decreased at 6 months after the HUG intervention was done. Considering psychosocial work environment, only influence of work and social support from supervisor had significantly increased when compared with the control group (p &lt; .01). For health outcomes, prevalence rate of musculoskeletal symptoms in the last 7-day and 3-month among the intervention and the control groups at post-intervention were not decreased compared to pre-intervention measurement. There was no day of sick leave reported by the intervention group but the control group had 2-day sick leave due to musculoskeletal problems. Work ability among the intervention group revealed slightly increased at 3 months and 6 months, while the control group showed not change at 3 months and slightly increased after completed intervention at 6 months. In conclusion, the finding suggested that the HUG program can contribute to reduce the risk factors of physical work environment and improve promotion factors of psychosocial work environment. While obvious effect on health outcomes should be investigated in a long-term period after intervention.
DOI: 10.14457/cu.the.2011.121
title: Multi-commodity flow model approach to a crew rostering problem

description: An airline crew rostering problem is a large-scaled and complex optimization problem that assigns crew members to the flight duties while satisfying agreements with the labor union, the government regulations, the carrier’s own policies, and other requirements. The traditional crew rostering problem considers only minimizing the total per-diem in order to reduce the airline expense. This paper presents the crew rostering problem for the international flights of Thai Airways. We propose a 0-1 multi-commodity flow problem whose objective function is to minimize the sum of the maximum of the per-diems and workloads among the crew members. Various test cases are generated from Thai Airways data set and solved by using the commercial optimizer IBM ILOG CPLEX. From the experiment results, the optimizer can solve the multi-commodity flow problems of small and medium sizes within 60 hours. However, the solutions give poor distribution of the per-diems and workloads among crew members where the standard deviations of the per-diems ranging from 1985.415 to 3855.295 and standard deviations of the workloads ranging from 8.7595 to 28.22391. The optimizer cannot solve the problems of large size within 60 hours.
DOI: 10.14457/cu.the.2011.122
title: Ethinc chinese women in Thai novels : the negotiation of identity, gender and generational transitions

description: This dissertation is a study of the interaction between Chinese and Thai cultures in contemporary Thailand. It is also a part of the study of the Chinese Diaspora. The focus is on a specific angle, namely, that of gender, female gender, and how the specific issues of women’s status and role according to Chinese tradition versus the norms of modern and Thai society, form an important part of the identity construction process of these women. The main objective of this dissertation is to examine novels produced by Chinese-Thais from the late 1960s to the present, focusing on novels that relate to gender. I then proceed to analyze how the identity of Chinese-Thai women is negotiated between the ethnic Chinese heritage and the adopted Thai way of life, including new ideas on female status. Finally, we analyze the social construction and reconstruction of the multi-faceted identity of Chinese-Thai women through the negotiation and generational transitions as reflected in Thai novels. The methodology I used is qualitative textual analysis. I focused on five novels, spanning the period of 1969 to 2008, a period that has seen large changes in the status of Chinese-Thais, and the way they are treated by the state. An important criterion in the selection has been exposure, through the written novels themselves and through renditions in popular television series. The novels are 1) Letter from Thailand by Botan of 1969, 2) Being with Gong by Yok Burapha of 1976, 3) Through the Scales of the Dragon by Prapason Sewikul of 1989, 4) The Last Petal of the Peony by Kantima of 2007, and 5) A Walk through Spring by Yuvadee Tonsakulrungruang of 2007. The findings of the dissertation are that Chinese-Thai women have been struggling, for decades, to change their role and status in the Chinese-Thai family and community. As assimilation ceases to be a focal point, and a large Chinese-Thai middle class is formed, this struggle turns into an inner community struggle to reconstruct a new Chinese-Thai identity, one which has no bias against women. These negotiations over the status of women take numerous forms of action in the novels I studied. One common type which is worthy to point out is that of raising the status of women, especially daughters’, at the expenses of that of sons. In such cases, the sons are depicted as either being failures or as being ungrateful towards their fathers, while the daughters represent success and gratitude.
DOI: 10.14457/cu.the.2008.1819
title: Kernel functions for support vector machines

description: Kernel functions are used in support vector machines (SVMs) to compute inner product in a higher dimensional feature space. The performance of classification or approximation depends on the chosen kernel function. There are some popular kernel functions such as linear, polynomial, and radial basis function (RBF) kernels. However, these common kernel functions may not be sufficient for the complex or large problems. This research proposes to improve the performance of SVM by using the non-negative linear combination of these common kernel functions. The obtained kernel functions are more flexible and allow better discrimination or approximation in the feature space. Then, the evolutionary strategies (ESs) are used for adjusting the parameters of SVM and the proposed kernel functions. In order to avoid the overfitting problem, the objective function in the evolutionary process is carefully designed. Training error, subset cross-validation, the bound of generalization error, and the stability of SVM are considered to be objective functions, and their experimental results are compared in this research. The proposed methods are experimented on benchmark datasets and real world problems, i.e. sentiment classification and handwritten recognition. Moreover, more flexible combined kernel functions are represented as trees. An algorithm for creating these tree kernel functions is presented, called GPES. This algorithm applies the genetic programming (GP) and the evolutionary strategy (ES) for evolving the hybrid kernel functions and their parameters. The experimental results are compared with a standard SVM classifier using the polynomial and RBF kernels with various parameter settings.
DOI: 10.14457/cu.the.2008.1820
title: Effects of binders and reinforcers on physical and chemical properties of granular activated carbon from eucalyptus bark

description: The present study reports the preparation procedure and characterization of the granular activated carbon (GAC) derived from eucalyptus bark using different types of binders and reinforcers. Firstly, eucalyptus bark was converted to powdered activated carbon (PAC) using the chemical method with H₃PO₄ as carbonizing/activating agent. The GAC was then prepared by mixing PAC with a mixture of binder to reinforcer. Four choices of binders to reinforcers were investigated in this work, i.e. CMC:kaolin, CMC:calcium carbonate, MC:kaolin and MC:calcium carbonate. The best choice among these four selected mixture was CMC:kaolin and the results illustrated that the optimal weight proportion of binder to reinforcer was 0.5:0.5, and the weight proportion of the mixture (binder:reinforcer) to PAC of 20:80. With this formula, the properties of the resulting GAC were: BET surface area 1,085 m² g⁻¹, bulk density 0.214 g cm⁻³, hardness number 75%, ash content 12.7% and pH 6.67. This condition gave the iodine and methylene blue numbers of 686 and 310 mg g⁻¹, respectively. It was observed that the adsorption capacity of the GAC product decreased with an increasing weight proportion of both binder and reinforcer to PAC. This was because the porous structure of the carbon was being filled by the presence of the binder and reinforcer. Although the final properties of the products were slightly lower than those of commercial GAC, they complied well with the national activated carbon standard (TIS.900-2004).
DOI: 10.14457/cu.the.2008.1821
title: Corporate governance and firm diversification : evidence from Thailand

description: The primary objective of this paper is to investigate relationship between corporate governance and firm diversification based on agency theory. Samples are listed companies in Thailand during 2000 to 2007. I apply corporate governance index covered all issues related to corporate. Next are degree and value of diversification. The first one is measured by Herfindahl Index and number of reported segments while the latter is from Excess Value. Excess Value stems from firm excess value as a result from diversification. For corporate governance and decision to diversify, it identifies that corporate governance is responsible for decision to diversify bringing about a confirmation of agency but not affect value of diversification. Aside from academic benefits, this paper sends a signal for stakeholders/ monitors about severity of agency problem in corporate/Thailand to pay more attention in monitoring and controlling the firm in order to reduce agency problem and increase corporate governance in those firms/Thailand.
DOI: 10.14457/cu.the.2008.1822
title: The role of target leverage on firms' financial decision : empirical evidence in Australia, Singapore and Thailand

description: This study investigates the role of target leverage on financing decisions of firms listed in the stock exchange in Australia, Singapore and Thailand between the periods of 1996-2006. These countries offer different environments for firms to raise external fund ranging from market-based to bank-based. The role of target leverage is examined in two aspects. The first aspect is, given that firms want to raise external fund, how would they decide between debt and equity. We test whether firms will select the source of fund that makes their leverage ratio closer to the target level. The second aspect is to test whether, when firms deviate from the target leverage ratio, they will try to adjust their leverage ratio back to the target level. Univariate and Binary logit regressions are applied in this study. The first aspect is tested by comparing between debt issuer and equity issuer. Consistent with the tradeoff theory, the results show that firms tend to select the source of fund that minimize the gap between actual leverage and the target leverage ratios. These results are consistent across countries used in the samples. The second aspect is tested by comparing between firms that involve in financing transactions and firms that do not involve in such transactions. The results show that firms in 3 countries when deviate from the target leverage ratio will adjust back to the target leverage ratio. Overleveraged firms tend to reduce their existing debt while underleveraged firms tend to issue debt
DOI: 10.14457/cu.the.2008.1823
title: Investigation of kinetics and intermediates of photodegradation of phenylurea herbicides on nanosized ZnO

description: The practical elimination of phenylurea herbicides from water by photocatalytic reaction was studied using zinc oxide as photocatalyst and by choosing diuron, linuron, and isoproturon as representatives for the herbicides. The catalytic activities were investigated, based on the rate of phenylurea herbicides disappearance. In particular, comparison was made on their initial activities. Under identical conditions, it was found that the extent of the degradation of the phenylurea herbicide was obviously affected by amount of photocatalyst, initial phenylurea herbicide concentration, pH of the solution, and temperature. The photocatalytic reaction on the surface of zinc oxide can completely degrade the phenylurea herbicide existing in the solution. Chemical structure and stability of the phenylurea herbicide affect the rate of degradation. The higher activity or the less stability of isoproturon gives higher rate of degradation than that of diuron and linuron. Several degradation intermediates are generated by reactions of hydroxyl radical attacking to several sites of phenylurea structure, during the photocatalytic process
DOI: 10.14457/cu.the.2011.123
title: Pharmacognostic specification and dioscorine content of dioscorea hispida tubers

description: Dioscorea hispida Dennst. dried tubers have been used as a crude drug in Thai remedy named Thoraneesanthakhat. It has traditionally been used to treat constipation. The aim of this research is to establish the pharmacognostic specification and determine the content of dioscorine in D. hispida tubers. The tubers were collected from 14 different locations throughout Thailand. The drawing of whole plant of D. hispida was illustrated in detail. The crude drug was traditionally prepared by slicing the tuber and sun drying. The macroscopic characters were longitudinal pieces or irregularly shaped, off-white colour with some light brown epidermis. The prominent anatomical and histological characteristics were starch granules and raphide crystal. The total ash, acid insoluble ash, loss on drying and water content should be not more than 3.44, 0.92, 11.50 and 11.55% w/w respectively whereas ethanol-soluble extractive and water-soluble extractive should be not less than 3.00 and 15.07% w/w respectively. The content of dioscorine in D. hispida dried tubers was identified using TLC image analysis compared to TLC-densitometry. The standard dioscorine was prepared from dried tubers by ethanol extraction, picrate crystallization, back extraction and column chromatographic purification. The identification of isolated dioscorine was confirmed by ¹H and ¹³C NMR spectra as well as previously reported spectra prior to be used as dioscorine standard. Dried tuber samples were successively extracted in ethanol by soxhlet apparatus. The extracts were analyzed for dioscorine content by TLC using Aluminium oxide 60 GF₂₅₄ neutral as stationary phase and methanol-chloroform (3 : 97) as mobile phase. The density of dioscorine spot at hRf value of 80 detected under UV254 was analyzed and transformed to peak area by the Scion Image software. Five concentrations of standard and 14 samples were developed on the same TLC plate. Each sample was quantitated in triplicate. For TLC-densitometry, the same protocol was performed using Camag Linomat syringe and Camag TLC scanner with winCATS software instead manual. The dioscorine content of the dried crude drug determined by TLC image analysis and TLC-densitometry were 0.66 and 0.72% w/w respectively. The polynomial regresstion data of both methods for dioscorine showed good linear relationship with a correlation coefficient of 0.999 in the concentration range of 2.50-12.50 μg/spot. The LOD and LOQ were 0.28 and 0.84 μg/spot by TLC image analysis and 0.37 and 1.13 μg/spot by TLC-densitometry respectively. TLC image analysis was valid for quantification of dioscorine in D. hispida tuber. This study provided scientific information for the quality control of D. hispida tuber ingredient in Thai traditional medicine.