cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.14457/cu.the.2005.1795
title: Synthesis of benzothiazole-based chelating resin for preconcentration of toxic metal ions

description: Polystyrene-divinylbenzene resin (PS-DVB) was functionalized with a benzothiazole group on the surface. PS-DVB with amino group was initially prepared by nitration and reduction reactions and subsequently treated with ethyl 2-benzothiazolyacetate (BA) to obtain the chelating resin with an amide linkage (BA-PS-DVB). On the other hand, the amino-PS-DVB was diazotized and coupled with BA to get the chelating resin with an azolinkage (azo-BA-PS-DVB). The resins were characterized by elemental analysis (EA) and infrared spectroscopy and the evaluated for its extraction of CD(II), Cu(II) and Pb(II) ions in water before their determinations by flame atomic absorption spectrometry (FAAS). Extraction conditions were optimized for batch method such as pH of solution, extraction time, and adsorption isotherm. The optimum pH for the extraction of Cd(II), Cu(II) and Pb(II) are 8.0, 7.0 and 6.0,respectively while the equilibrium time of all three ions were reachedwithin 10-20 minutes. Adsorption behavior of all metal ions followed Langmuir adsorption isotherm. In column method, the optimum flow rates of metal sorption onto BA-PS-DVB and azo-BA-PS-DVB column were 2.5 and 4.0 mL min. Metal ions sorped onto columns were eluted by 0.5 to 2.0 M HNBO[subscript3]. The preconcentratin factors of Cd(II) and Cu(II) on azo-BA-PS-DVB and Cu (II) on BA-PS-DVB were 50, 50 and 20, respectively. The present column method gave good validation results: 71.2 and 74.0% recovery for Cd (II) and Cu(II) and overall % RSD less than 10% (n=15).
DOI: 10.14457/cu.the.2005.1796
title: Attachment of biotin on silicon surface-tethered poly(acrylic acid) brushes

description: Surface-tethered poly(acrylic acid) (PAA) brushed can potentially be used as functional nanometer-thick film for many technological applications. Their carboxyl groups serve as versatile moieties for a wide range of chemical modificantion including an attachment of biomolecules. In this research, linear and branched poly(tert-butyl acrylate) (PtBuA) brushed were prepared by surface-intiated atom transfer radical polymerization of tert-butyl acrylate and self-condensing vinyl copolymerization of PtBuA with acrylic acid 2-(2-bromopropionyloxy)ethyl ester (BPEA), respectively. Linear and branced PAA brushed were subsequently obtained after tert-butyl groups of PtBuA brushes were removed by acid hydrolysis. The carboxyl group density of linear and branched PAA brushes can be varied as a function of chain length (MW) and comonomer ration (grammar), respectively. The success of biotin attachment to the carboxyl groups of both linear and branched PAA brusheswas verified by FT-IR analysis and the binding with fluorescein-conjugated streptevidin which was visualized by fluorescence microscope.
DOI: 10.14457/cu.the.2005.1797
title: Bounds in a normal approximation of an infinite urn model

description: Let N (n) be a Poisson random variable with parameter n. An infinite urn model is defined as follows: N (n) balls are indenpendently placed in an infinite set of urns and each ball has probability Pk&gt;0 of being assigned to the k-th urn. We assume that Pk is &gt;= Pk+1 for all k and sigma [superscript infinity] [subscript k=1 Pk = 1. Let Zeta [subscript N (n)] be the number of occupied urns after N (n) balls have been thrown. Dutko showed in 1989 that under the condition lim [subscript n vector infinity Var (Zeta [subscript N (n))] = Infinity, We have lim [subscript n vector infinity] F [subscript n (x) = phi (x) Where F[subscript n] is the distribution function of Z [subscript (n) - E (Z [subscript N(n) / squairroot Var (Z [subscript N (n)] and phi is the standard normal distribution. However, Dutko did not give a bound of his approximation. In our work, We use the technique in Chen and Shao (2001) to give uniform and non-uniform bounds of the approximation.
DOI: 10.14457/cu.the.2005.1798
title: Aircraft spare parts planing and control

description: In today's competitive airline environment, maintenance and inventory controls problem have been the primary focus area of maintenance service organization. This problem can be ameliorated by a MRP system. Fortunately, the increasing of the advent of the computer in nowadays gives an opportunity for development of material requirement planning. This study concentrates on the improvement of a spare part inventory control system in Technical department, Thai Airways international Public Company Limited, incorporating a decision support system for inventory management. The decision support system involves determining an optimum ordering policy and making report of planned monthly demand and planned order releases for management level. The causes of an ineffectiveness of the current spare part inventory control system are ameliorated. The method of development included: current system analysis, data collection and analysis, system design and program testing and validation. After testing the program, the proposed system is more cost-effective and more accurate than the current system. The inventory related costs reduced 29.4%. the time spent in spare parts planning and control process, and the shortage were reduced. However, to improve the proposed system to be more accurate, the necessary information such as past demand information should be more gathered. After a system validation by the end users within the Technical department, it was concluded that the program performs the calculation as expected, ease of use, and provides sufficient information for the users.
DOI: 10.14457/cu.the.2005.1799
title: Effectiveness of estrogen cream in the treatment of vaginal atrophy using classical vaginal aplicator compared to extension tube

description: Objective: To compare the effectiveness of estrogen cream using classical vaginal applicator versus extension tube vaginal applicator for the treatment of vaginal atrophy. Design: Randomized controlled trail. Setting: King Chulalongkorn Memorial Hospital, Thai Red Cross Society. Methods: A total of 120 postmenopausal women with vaginal atrophy were recruited. Patients were randomized into two groups: classical group (n=60) who used classical vaginal applicator and extension group (n=60) who used extension tube applicator. Partients in classical group received 1 gram of conjugated estrogen cream daily for 4 weeks and the other group received 1.1 grams of the same medication and period. Vaginal maturation index (VMI), vaginal atrophy score (VAS) were assessed. Number of days of use and patients' acceptability were recorded. Adverse events were also monitored. Results: Fifty seven patients in classical group and 58 in extension group completed the study. The mean of VMI was significantly increased in extension group more than classical group (p=0.007). The VAS was significantly improved in extension group more than classical group (p=0.009). The compliance with extension tube was significantly higher than classical vaginal applicator (p=0.008). Considering the acceptability and the occurrence of adverse events, there were no statistically significant differences between two groups. Conclusion: The effectiveness in the treatment of vaginal atrophy with estrogen cream was significantly higher when using extension tube than classical vaginal applicator. The compliance with extension tube was also higher than with classical vaginal applicator.
DOI: 10.14457/cu.the.2005.1800
title: Synthesis of nickel/magnesium/zirconium mixed oxide, catalysts by co-precipitation method

description: Mix metal oxide catalysts of Ni/Mg/Zr were prepared by four different methods: co-precipitation (CT), citrate precursor technique (CT), modified citric acid precursor technique (MCT), modified citric acid/ethylene glycol precursor technique (MCTE). The mixed metal oxides were characterized by several techniques: X-ray diffraction (XRD), Transmission electron microscopy (TEM), Scanning electron microscopy (SEM), Energy dispersive x-ray analysis (EDX), Fourier transorm infrared spectroscopy (FTIR), Thermogravimetric analysis (TGA) and Brunauer-emmet-teller (BET). Parameters influencing the characteristics and properties of the mixed metal oxides were studied, such as Mg/Zr molar ratio, Ni content, calcinations temperature, calcinations time and additive (Sn.). It was found from the XRD results that when using Mg/Zr molar ratio at 4 and 15% wt Ni, the mixed metal oxide exists as cubic Mg-ZrO2 phase. In the CP method, calcinations was performed at lower temperature (600 ํC), it yielded oxides with surface area of 136 sq.m/g and small pore size. In the CT method in which one calcinations was performed at high temperature (800 ํC), the oxides had very low surface area and pore size. By MCT method in which two calcinations were performed, it yielded oxides with high surface area (145 sq.m/g) and large pore size. The MCTE method also yielded oxides with high surface area (144 sq.m/g). The morphology of the oxides observed by SEM showed that the oxides had spherical shape with nanosize.
DOI: 10.14457/cu.the.2005.1801
title: The BCC-HCP transition temperature in titanium metal using the classical molecular dynamics method

description: Molecular dynamics is carried out in order to calculate the component of Helmholtz free energy of the hcp and the bcc titanium at temperature from 300K to 1,300K. The internal energy difference is calculated from the potential energy difference. The Finnis-Sinclair potential energy is chosen to represent the potential energy of titanium. The total entropy consists of the electronic entropy and the vibrational entropy including harmonic and anharmonic vibrational entropy. The transition temperature is identified at 880K where Helmholtz free energy difference between the two phases is equal to zero. This finding is in agreement with experiments.
DOI: 10.14457/cu.the.2005.1802
title: Identificaton of SNP markers in the giant tiger shrimp Penaeus monodon

description: Single nucleotide polymorphism (SNP) by expressed sequence tags (SBE) of genes in functionally important genes of the giant tiger shrimp (Penaeus monodon) was examined. Primers were designed from 101 gene homologues initially isolated by the EST approach and tested against genomic DNA of wild P. monodon. Forty-eight gene homologues were successfully amplified and subjected to SSCP analysis. Forty-four of which were polymorphic. Five genes including ribophorin I, receptor for activated protein kinase C (RACK), defender against cell death 1 (DAD1), thioredoxin peroxidase and calponin 1 were chosen for further studies. SNP of these genes were confirmed by direct sequencing. Simplification of SNP detection was preliminary carried out by PCR-RFLP and PCR allele-specific amplification (PASA). RACE-PCR was carried out and successfully identified the full length of ribophorin I and RACK. In addition, the genomic full length of DAD1, thioredoxin peroxidase andcalponin 1 were also successfully characterized by genome walk analysis. Polymorphism of 5'UTR and 3'UTR of each gene was successfully genotyped by SSCP analysis. Semi-quantitative RT-PCR was carried out. Relative expression levels of ribophorin I, RACK, DAD1, thioredoxin peroxidase and calponin1 in ovaries and testes of juvenile P. monodon were significantly different (P&lt;0.05). However, the expression levels of RACK in male and female P. monodon broodstock were not significantly different. Therefore association analysis between SNP thorough SSCP and gene expression levels on male and female P. monodon should be considered separately. A time course response of these genes following the thermal stress was also examined. Only the expression level of thioredoxin peroxidase in ovaries and RACK in hemocytes of juvenile shrimps was significantly higher than that the normal level at 6 and 12 hours post thermal treatment, respectively (P&lt;0.05). Correlations between SNP through SSCP and the corresponding gene expression in broodstock and juveniles of P. monodon were examined. Due to limited sample sizes, several SSCP genotypes carried by single individuals were therefore excluded from statistical analysis. Non-significant associations between SNP and gene expression levels were found in both broodstock and juvenile P. monodon.
DOI: 10.14457/cu.the.2005.1803
title: Groundwater defluoridation by ultra low pressure reverse osmosis membrane and nano filtration membrane

description: Grondwater quality of 199 village waterworks in Lamphun province, Thailand was investigated. It was found that groundwater of 53 village waterworks (44.54%) contain fluoride concentration above 0.7mg/L which is the bottled drinking water standard by Ministry of Industry of Thailand. Dental fluorosis investigation in children aged between 13 and 18 were also studied. It was found that the severe cases of dental fluorosis were observed significantly in the high fluoride concentration area. Besides the investigation of groundwater quality and severity of dental fluorosis, the experiments of ULPRO membrane (UTC-70) and NF membrane (UTC-60) for defluoridation of fluorotic groundwater were studied so as to remove excessive amount of fluoride in groundwater for serving as drinkable water. Groundwater from 2 selected sites in fluorotic area in Lamphun province, Thailand, namely, Pra Too Khong Bottled Drinking Water Plant (site A) and San Pa Hiang Membrane Plant (site B) were collected between September 2005 and January 2006. Groundwater from site A containing fluoride concentration in the range of 12.05-16.98 mg/L was defined as very high fluoride concentration site (&gt;5 mg/L) whereas groundwater from site B containing fluoride concentration in the range of 2.84-3.12 mg/L was defined as high fluoride concentration site (1-5 mg/L). It was found that the maximum percent fluoride rejection of UTC-60 membrane in groundwater from site A was about 80% under the operating transmembrane pressure of 0.5 MPa at the feed pH values of natural pH (about 8) while the maximum percent fluoride rejection in groundwater from site B was about 60% at the feed pH value of 7. In the case of UTC-70 membrane, more than 90% of fluoride rejection under OTP of 0.5 MPa at the feed pH value of 7 was achieved in the groundwater from both sites. Thus, it could be stated that the performance of UTC-70 membrane on fluoride removal was higher than the UTC-60 membrane. In addition, based on the membrance experimental results, it was observed that the approximate pH value at an isoelectric point of UTC-60 membrane was 5 while the pH value at an isoelectric point of UTC-70 membrane was 6. Furthermore, it was found that UTC-70 membrane should not be operated at the feed pH value lower than about 4 so as to avoid negative rejection of fluoride.
DOI: 10.14457/cu.the.2005.1804
title: Removal of phenolic compounds by peroxidase derived from agricultural waste

description: This study focuses on the removal of phenolic compounds by peroxidase derived from agricultural waste, The phenols studied are phenol, o-cresol, n-cresol, p-cresol, 2-chlorophenol, 3-chlorophenol, 4-chlorphenol, catechcol, resorcinol, hydroquinone, 1-naphthol and 2-naphthol. The extraction of crude POD from sweet potato with phosphate buffer exhibited the highest activity and removal efficiency. The optimum conditions for removal of phenol was at 30 ํC, 100 min, pH 7,20 ppm of phenol, 0.5% w/w of H[subscript 2]O[subscript 2], 10 units/mL of crude POD, 20 ppm of PEG-6000 and phosphate buffer as solvent. Rate of conversion of phenol under this condition was 1.045 [micromol] per h. The optimum condition for removal of phenols was at 30 ํC, 100 min, pH 7,20 ppm of phenols, 1.0% w/w of H[subscript 2]O[subscript 2], 4 units/mL of crude POD and phosphate buffer as solvent. The product from the removal of phenol by POD is polymer consisted of 2-phenoxy-biphenyl, 1,1'-biphenyl-2,2'-diol and 4-phenoxy-biphenyl while that derived from the removal of o-cresol by POD is 2,2'-ethylenediphenol.
DOI: 10.14457/cu.the.2005.1805
title: Integrated system for aqueous nitrate removal using Fe0/CO2 reduction, iron precipitation, and ammonia stripping

description: To investige the integrated system for aqueous nitrate removal using Fe[superscript 0]/Carbon dioxide reduction, iron precipitation, and ammonia stripping. Results show that the bubbling of Carbon dioxide flow rate at 200 mL/min was sufficient for supplying H+ into solution to create and acidic environment favorable to nitrate reduction by Fe[superscript 0]. Sigmoidal model equation satisfactorily describes the S-curve behaviors of nitrate reduction, ferrous accumulation and ammonium formation. The t1/2 obtained from the sigmoidal model can serve as a powerful tool for the comparison of nitrate reduction rate. In the system with various water characteristics, it found that humic acid significantly inhibited the reduction of nitrate. Calcium ions also strongly retarded nitrate removal, whereas chloride ion promoted the nitrate removal. Removal of ferrous from Fe[superscript 0] corrosion was investigated using the fluidized sand bed reactor. The resultsshow that the lower air flow rate of 20 mL/min could achieve up to 95% removal which provided a better performance than at higher flow rate. Under the studied conditions, air flow rate and surface area of sand were found to play an important role for iron pelletization onto the sand. Ammonia was the dominating end product from nitrate reduction by Fe[superscript 0]/Carbon dioxide processes. The optimum pH at 12 is recommended for ammonia stripping and the removal efficiency increased with increasing air flow rate. Considering continuous operation, nitrate of 23 mg-N/L was reduced to 2.9 mg-N/L within 2.5 hours of stripping under influent feeding rate, Fe[superscript 0] dosage, and Carbon dioxide gas flow rate of 3 L/hr, 60 g, and 200 mL/min, respectively. However, to maintain effluent nitrate to comply with drinking water quality standard of nitrate, supplement of 40 g of Fe[superscript 0] at every 27 hrs of operation was needed. According to field test, dissolved organic carbons and calcium ion existing ingroundwater strongly inhibited nitrate removal similar to the batch study. Nonetheless, 70% removal of nitrate was still achieved due to enhancement effect from high chloride content of the tested groundwater.
DOI: 10.14457/cu.the.2005.1806
title: Characterization of Na+- atpase in the halotolerant cyanobacterium aphanothece halophytica

description: Extrusion of sodium ion is needed to balance and maintain sodium level for microorganisms to survive in hypersalin environment. Activity of Na+- ATPase in halotolerant cyanobacterium aphanothece haolphytica was investigated. Cells were preloaded with 22Na+ and the extrusion of 22Na+ from cells was followed by energizing the cells with glucose. To ascertain that this Na+ extrusion is Na+- ATPase, the plasma membranes vesicles were prepared by aqueous polymer two-phase partitioning with dextran and polyethylene glycol and used for the assay of Na+- ATPase activity by measuring ATP hydrolysis. The ATPase activities were stimulated to greatest extent in the presence of 100 mM Na+ and 5 mM Mg2+ ions, pH 7.6. The K[subscript m] value for ATP and Na+ ions were 1.66 mM and 25 mM respectively. The maximum velocities (V [subscript max])were 0.66 and 0.50 umol/min/mg protein using ATP and Na+ as variable substrate respectively. The activity was inhibited by vanadate, a potent inhibitor of P-type ATPase. The activity was decreased about half of original value by 0.01 mM socium vanadate and 0.20 mM gramicidin. Alternatively, the membrane vesicle containing Na+- ATPase, exhibited 22Na+ transport by the addition of ATP, which was inhibited by sodium ionophore and gramicidin. It is likely that the Na+- ATPase belongs to P-type and is involved in Na+ transport. The enzyme activity was enhanced by the high salinity of growth medium.
DOI: 10.14457/cu.the.2005.1807
title: Numerical simulation of the December 26, 2004 :Indian ocean Tsunami

description: The December 26, 2004 tsunami is one of the most devastating tsunami in recorded history. It was generated in the Indian Ocean off the western coast of northern Sumatra, Indonesia at 0:58:53 (GMT) by one of the largest earthquake of the century with a earthquake magnitude of M[subscript w] = 9.1-9.3 In this study, we focus on the best-fitted tsunami source based on geophysical and seismological data, and the use of accurate bathymetry and topography data. Then, we simulated the large scale features of the tsunami propagation, runup and inundation. The numerical simulation is performed using GEOWAVE model. GEOWAVE consists of two components: the modeling of the tsunami source (Okada, 1985), and the computation of the wave propagation and inundation based on a second-order fully nonlinear Boussinesq equations. The tsunami source is used as initial condition in the tsunami propagation and inundation model. The tsunami source model is calibrated by usingavailable tide gauge data and anomalous water elevations recorded by Jason1 altimeter (track 129, cycle 109). The simulated maximum wave heights for the Indian Ocean are displayed and compared with observations with a special focus on the Thailand coast.
DOI: 10.14457/cu.the.2005.1808
title: Electrical property characterization of electrolyte materials in solid oxide fule cells by AC impedance spectroscopy

description: Yttria-stabilized zirconia (YSZ) is an important solid electrolyte used in solid oxide fuel cells (SOFCs) due to its good electrical (0.1 siemens/cm at 1000 ํC) and mechanical properties. The electrical property of 3, 8 and 10 mol% Y[subscript 2]O[subscript 3]-doped ZrO[subscript 2] were measured using AC-impedance spectroscopy, in the temperature range of 275-600 ํC and over the frequency range of 0.05-10[superscript7] Hz. From the impedance spectra, the bulk and grain boundary resistances of YSZ pellets from various suppliers (MEL, TOSOH, and DAIICHI) were significantly influenced by the containing impurities and the sintering conditions. The impurities in the starting power were analyzed using x-ray fluorescence technique (XRF), while the microstructure was investigated using scanning electron microscope (SEM). The correlation between the electrical conductivity and sintering temperature from various electrolyte materials was developed. As a result, the AC-impedance spectroscopy technique in combination with microstructural investigation can be used to study the electrical property of YSZ effectively.
DOI: 10.14457/cu.the.2005.1809
title: Fixation of activated carbon powder on knitted cotton fabrics

description: This research was concerned with the fixation of activated carbon powder from coconut shell on knitted cotton fabrics using butadiene-acrylonitrile copolymer binder. The application was carried out by pad dry cure technique; first padding with activated carbon dispersion and then binder solution. The fixation was performed at the temperature ranging from 140 -170 degree Celsius. The adsorption efficiency was evaluated by methylene blue number and percent formaldehyde absorption. Wash fastness and rubbing fastness as well as properties evaluation of treated fabrics were performed. The results showed that activated carbon was fixed onto knitted fabric through binder film network. An increase in the amount of binder, fixation temperature and curing time improved the fastness properties of activated carbon but reduced the absorption efficiency of activated carbon, judged by the reductions of iodine number and percent formaldehyde absorption. After washing, the absorption efficiency of fixed activated carbon was recovered. This phenomenon was believed that during washing crack and peel-off of binder film might occur, allowing an increase in the adsorption capacity observed. The optimum conditions for activated carbon fixation were recommended as follows : the amount of binder of 50 gram per liter, fixation temperature of 150 degree Celsius and curing time of 4 minute and wash-off process after treatment.