cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.14457/cu.the.2005.1875
title: Effects of Polysaccharide gel from Durain fruit-hall on growth and protection against microbial in fection in The black tider shrimp

description: Growth performance in black tiger shrimp (Penaeus monodon) and its immunogenesis was evaluated on feeding with durian polysaccharide gel (PG) additive diet. Diets in treatment groups added 0.5, 1.0 and 2.0 grams PG in 100 grams diet, shrimp diet without PG was used in control group. Each group of black tiger shrimp was fed with the PG additive diets for 56 days in closed-recirculating water system pond. Body weight and total length of shrimps were measured after 4 weeks and 8 Weeks, respectively. Survival rate was observed. Immunogenesis was evaluated by the total hemocytes count and phenoloxidase activity test. The results showed that body weight of shrimp in 2.0% PG group was higher (P&lt;0.05) than that of control after feeding for 8 weeks, long total length was also observed. Survival rate of shrimp in groups feeding with 0.5 and 1.0 % PG were significantly higher than that of control. Feed conversion ratio (FCR) of PG feeding groups were significantly lower (P&lt;0.05) than that of control. Total hemocytes count and phenoloxidase activity in blood were higher (P&lt;0.05) in groups feeding with 1.0 and 2.0% PG than that of control group. Oral administration of PG additive diet seemed to increase the survival shrimps against the impact of Vibrio harveyi 1526 and white spot syndrome virus (WSSV) infection in groups fed with 1.0 and 2.0% PG compared with control group. The survival rates of shrimps after 4 weeks prefeeding with 0.0, 0.5, 1.0 and 2.0% PG were 0, 0, 57 and 17%, respectively, at day 11 of WSSV infection; the relative percent survival (RPS) values at day 7 were 9, 94 and 51%, respectively. The survival rates after 8 weeks prefeeding were 0, 4, 4 and 33%, respectively, at day 14 of infection; RPS values at day 10 were -37, -63 and 11%, respectively. Prefeeding of the same three diet formulas for 8 weeks were provided continuously same survival rate at S0, 58, 67 and 75%, respectively, after day 4 of V. harveyi 1526 infection; RPS values at day 3 were 18, 32, and 50%, respectively. The disease resistance of P. monodon against WSSV in the treated groups of 4 weeks prefeeding 1.0% PG diets showed the best RPS value at 94% compared with the other treatments. The disease resistance of P. monodon against V. harveyi 1526 in the treated groups of 8 weeks prefeeding 2.0% PG diets possessed the highest RPS values only at 50%. These results indicate the possibility of PG affected P. manodon immune stimulation. The in vitro antibacterial activity determination of PG against a gram negative bacterium, V. harveyi 1526, demonstrated the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of PG at 6.0 and 12.5 mg/ml, respectively. The results suggest that PG at 1.0% in diet stimulate growth and immune system of P. monodon shrimp juveniIes in this study.
DOI: 10.14457/cu.the.2005.1876
title: Fractional crystallization and characterization of rice bran wax

description: This study is aimed to purify rice bran wax by the modified TREF with Crystaf technique. Sand was used as a solid support and hexane as a solvent in crystallization step. After crystallization was completed, the fraction in hexane was gently removed. Then, wax was eluted at various temperature i.e., 30, 40 and 50°C, with hexane to obtain four fractioned waxes, respectively. The physical properties of all fractioned waxes were measured, i.e., saponification value, acid value, iodine value and drop melting point. The identification of the possible components in each fractioned wax was performed by FT-IR and GC-MS. The results of FT-IR indicated that all fractioned waxes were ester waxes. The GC-MS data showed the presence of free fatty acid and fatty acid esters in these fractioned waxes. Only fractioned wax eluted at 40 °C had acid value in the range of 5.0-5.5 which was better than the others and commercial refined wax. Accordingly, the fractioned wax eluted at 40 °C had high value and can be used in cosmetics and medicine industries.
DOI: 10.14457/cu.the.2005.1878
title: Reinforcement of natural rubber by silica generated from sol-gel process of silanes in latex

description: Alkyltriethoxysilanes and tetraethoxysilane (TEOS) were used as precursors to generate silica in concentrated natural rubber latex. Both silanes were mixed with the concentrated latex incorporated 0.7% NH3, and heated at 50°C for 5 days in order to complete the sol-gel process of both silanes. Four types of ethoxysilanes ; tetraethoxysilane (TEOS), vinyltriethoxysilane (VTOS), ethyltriethoxysilane (ETOS), and i-butyltriethoxysilane (BTOS), were studied. The conversion of silane to silica particles inside the rubber depended on size and polarity of the alkyl group in the alkyltriethoxysilane. The inﬂuences of various molar ratios between alkyl-triethoxysilane and TEOS on the morphology and mechanical properties of the composites were investigated. The modiﬁed silica particles obtained from the mixed silanes were well dispersed in the NR matrix as observed by SEM and TEM. Silicon-29 solid-state NMR technique was also used to analyze the chemical structures of the in siru generated silica. For sulfur-cured composites, the use of VTOS/TEOS (5, l0 and 20 mol% VTOS) resulted in an increase of tensile modulus, tensile strength, and tear strength over to the composite prepared from only TEOS. The mechanical properties results lead to a conclusion that the vinyl group from VTOS most probably participates in the sulfur vulcanization. Cure characteristic and swelling behavior in toluene were also investigated.
DOI: 10.14457/cu.the.2005.1879
title: Physical and biological properties of collagen/gelatin scaffolds

description: Biocompatible gelatin was used as a base material to produce a scaffold and to substitute a large portion of collagen, which is an expensive biomaterial mainly used in skin substitute. The collagen/gelatin scaffolds with various blending compositions were fabricated by freeze drying and dehydrothermal (DHT) crosslinking techniques. The effects of gelatin type, solution concentration, blending composition and DHT treatment time on the chemical and physical properties of the scaffolds were investigated. It was found that crosslinking degree of the scaffolds, determined by 2,4,6-trinitrobenzene sulphonic acid (TNBS) method, mainly depended on gelatin type and DHT treatment time. The different scaffolds provided different morphology depending on gelatin type, solution concentration and collagen content. In addition, compressive modulus of gelatin scaffolds could be improved by collagen blending up to 10 kPa. Swelling property of the scaffolds directly related to the morphology and compressive modulus. The in vitro biodegradation test by lysozyme showed that collagen blending could decrease the degradation rate of gelatin scaffolds. Crosslinked gelatin scaffolds degraded within a day while crosslinked collagen/gelatin scaffolds could remain up to 3 weeks in lysozyme solution at 37°C. The results from in vitro cell culture revealed that mouse fibroblasts could proliferate on all scaffolds. At 48th h after the culture, the number of proliferated cells on collagen/gelatin scaffolds prepared from different blending compositions was comparable to that on pure collagen scaffolds. The results proved that gelatin could be used to partly replace collagen by 70-90% for scaffold fabrication. Therefore, a large amount of collagen used in scaffold fabrication could be reduced leading to a much lower cost of biomaterials used.
DOI: 10.14457/cu.the.2005.1880
title: Coating of polyamide fibers with polyelectrolyte multilayer thin films to improve wash fastness

description: Polyelectrolyte multilayer thin films (PEM) were coated on polyamide fibers, namely nylon and silk fibers, using the Layer-by-Layer technique and characterized using the spectrophotometry technique. PEM built from poly (diallyldimethylammonium chloride) (PDADMAC) and Scarlet acid dye were coated on nylon fibers and the parameters controlling the growth of the PEM were found to be: deposition time, salt concentration, polyelectrolyte concentration, and dye concentration. The deposition of the PEM was complete and constant even with deposition time as short as 15 seconds. The growth of the PEM increased with increasing salt concentration and polyelectrolyte concentration up to 0.5 M and 1 mM, respectively. Beyond either of these concentrations, the deposition of the PEM films decreased. Although PDADMAC concentration above 1mM lead to a decrease in film thickness, increasing dye concentration had a different effect and lead to a constant increase even with concentration as high as 50 mM. Regarding the acid dye loading and release behavior on silk, it was found that the main parameters influencing its loading were exhaustion time, salt concentration, and pH condition of dye bath. On the other hand, the spinning rate of the fibers in the solution shown to have no effect on the dye loading. The results also indicated that the rate of dye release depended mainly on the immersion time at constant temperature and on the pH of the soaping solution. When the pH of the soaping solution was increased, the amount of dye release was also increased. In the last part of the work, PEM were coated on dyed silk to improve the wash fastness of the fibers. The efficiency of the dye release protection was investigated by coating PEM built from PDADMAC with poly (4-styrenesulfonic acid-co-maleic acid) (PSS-co-MA) and PDADMAC with poly (sodium 4-styrene sulfonate) (PSS) at pH 4.5 and pH 3, respectively. It was found that increasing thickness of the PDADMAC/PSS-co-MA PEM did not improve the efficiency of dye release protection. Contrarily, increasing thickness of the PEM assembled from PDADMAC and PSS resulted in a better dye release protection especially when the top layer was PSS. In that case the dye release was found to be about 47 percents less than conventional uncoated dyed silk (no PEM).
DOI: 10.14457/cu.the.2005.1881
title: The influence of molecular weight of chitosan on physical and biological properties of collagen/chitosan scaffolds

description: Biopolymer blends between collagen and chitosan have good potential for production of biocompatible scaffolds. However, the relationship between the molecular weight of chitosan and its effect on physical and biological properties of collagen/chitosan scaffolds have not been clearly elucidated. This research aims to investigate the effects of molecular weight of chitosan on physical and biological properties of collagen/chitosan scaffolds. Porous scaffolds were fabricated by freeze drying solutions of collagen, chitosan, and collagen/chitosan blends and then crosslinked by dehydrothermal treatment (DHT). Various scaffolds were prepared using four chitosan samples with various molecular weights (Mv, 4.8k-880k) and blending compositions. Fourier transform infrared (FT-IR) spectroscopy proved that collagen/chitosan scaffolds in all blending compositions contained only physical but not chemical interaction in molecular level. The compressive modulus of scaffolds decreased with increasing the compositions of chitosan, but, for collagen blended with high molecular weight chitosan (880k), the compressive modulus increased, especially at blending composition of 30% chitosan. Equilibrium swelling ratios of approximately 6-8, carried out in phosphate buffered saline at physiological pH (7.4), were found in case of collagen dominate scaffolds. The lysozyme biodegradation test demonstrated that the presence of chitosan, especially the high molecular weight, could significantly prolong the biodegradation of collagen/chitosan scaffolds. In vitro culture of L929 mouse connective tissue fibroblasts and Detroit 551 human dermal fibroblasts evidenced that collagen scaffold with lower molecular weight chitosan was more effective to promote and accelerate cell proliferation than pure collagen and collagen/high molecular weight chitosan scaffolds, particularly for scaffolds containing 30% of chitosan. The results elucidated that the blends of collagen with low molecular weight chitosan have a high possibility to be applied as new materials for skin tissue engineering.
DOI: 10.14457/cu.the.2005.1882
title: Developement of coursewares on digital modem using C6711 DSK

description: The objective of this study is to develop an educational courseware on digital modem used primarily as a teaching tool in communication laboratory for undergraduate students in Chulalongkorn University and National University of Laos. The courseware covers various basic topics on digital communications with essential background theories The study methodology mainly used in this courseware contains both MATLAB simulations concerning essential basic theories on digital communication system and implementations on digital modem using C6711 DSK. This laboratory package helps set digital communication laboratory, provide an extensive knowledge on digital communication theory, give an interaction of study in digital communication theory and an ability to analyze the problems that occur in practical work and gain skill on hardware controlling in laboratory.
DOI: 10.14457/cu.the.2005.1883
title: Theoretical study of pinacol rearrangement using Acid-Catalyzed System and ZSM-5

description: Pinacol rearrangements using acid-catalyzed system, ZSM-5 and metal substituted molecular sieve catalyst have been investigated using density functional theory method at B3LYP/6-31G (d) level of theory. The ZSM-5 catalyst was modeled as 3T and 5T cluster models. The metal substituted molecular sieves represented by Fe (II) and Cu (ll) substituted in zeolite framework were modeled using Fe-3T and Cu-3T cluster models. The results show that activation energies of pinacol rearrangement over Fe-3T and Cu-3T are 29.63 and 37.11 kcal/mol, respectively. As a result, Fe substituted in framework of zeolite presents higher catalytic activity for pinacol rearrangement than Cu substituted in zeolite framework. Moreover, the pinacol rearrangements of propylene glycol conversion to propanal and propanone via transition states TS1, TS2 and TS3 have been investigated using acid-catalyzed system and ZSM-5 in order to compare the product distribution ratio. In the acid-catalyzed system, the four water-addition models I to IV, were obtained. The number of hydration water interacting with the transition states of three concerted pathways has obviously affected the product ratio. Estimated percentages of product composition computed from activation free energies of each reaction models were carried out. The percent ratios of product propanal to propanone based on models I, II, III and IV are [99.88]:[0.12], [99.81]:[0.19], [89.01]:[10.99] and [46.59]:[53.41], respectively while the percent ratios of product propanal to propanone based on 3T and 5T cluster models are [2.36]:[97.64] and [2.56]:[97.43], respectively.
DOI: 10.14457/cu.the.2005.1884
title: A neural network modeling and control for etherification hybrid process

description: The Etherification Processes are recently improved by the hybrid mix of reaction unit and separation unit. The hybrid processes give a better production but also more complex behaviour. The conventional Proportional Integral Derivative (PID) controllers which are widely used ‘in the industrial chemical processes, are the linear controllers, however, able to control the non-linear and complex processes, but give the slow responses, low performances, limited operating ranges and the performances are not guaranteed in cases of disturbance changes and plant-model mismatches. Recently, the Neural Network control techniques have been successfully applied to these highly non-linear and complex systems due to the recent availability of advanced computer technology. In this research, the neural networks are used as a plant model and controller in a Proportional Integral-Nonlinear Internal Model Control (Pl-NIMC) cascade strategy. The simulation results involve the use of Pl-NIMC cascade control for set point tracking and disturbances rejection in both nominal and plant-model mismatches conditions compared with the conventional PlD cascade control. The Pl-NIMC cascade control strategy was found to be better than the conventional PID cascade control in all cases. These results justify the use of Neural Network control technique in a highly non-linear and complex process which is difficult to control such as this.
DOI: 10.14457/cu.the.2005.1885
title: Synthesis and-binding properties of pyrrolidinyl peptide nucleic acids bearing (1S,2S)-2-aminocyclopentane carboxylic acids space

description: A solid phase protocol for the synthesis of a new peptide nucleic acid (PNA) carring all four nucleobases has been developed. The PNA monomers in this research consist of a nucleobase-modified pyrrolidine derivatives with cis-D stereochemistry and (1S,2S)-2-aminocyclopentanecarboxylic acid (ACPC). The optimized solid phase synthesis conditions include the use of Pfp-activated monomer with HOAt and DIEA for 30 minutes in the coupling step. For capping step, lauroyl chloride and DIEA were used in order to facilitate the purification of PNA. The average coupling yield in each step was generally over 95 %. A number of mixed bases PNA with 5-15 mer in length were successfully synthesized by this protocol. Tm studies with complementary DNA showed that the PNA can form a stable hybrid with high affinity and sequence specificity for Watson-Crick type base pairing (A-T, C-G) exclusively in an antiparallel fashion. These PNA also exhibited a strong preference for binding to DNA over RNA and over self pairing.
DOI: 10.14457/cu.the.2005.1886
title: Synthesis of 1-phenyl-3-methyl-4-stearoylpyrazol-5-one doped mesoporous silica for removal os metals from industrial wastewater

description: This work is aimed at evaluating the optimum condition for the synthesis of HPMSP doped mesoporous silica to be used as an effective sorbent for the removal of metals from industrial wastewater. Effect of silica precursors was studied which showed the good ordered arrangement of mesopore and the narrow pore size distribution of the HPMSP modified materials when the silica precursor was TEOS or calcined mesoporous silica. The synthesis facility, morphology and the Cu (II) extraction capacity of different materials were compared. The results indicated that the silica prepared from 0.18 CTAB/TEOS mole ratio was the most effective sorbent. Other factors influencing the Cu (II) extractability of this sorbent investigated by SPE column method revealed the crucial role of an extraction flow rate. The maximum capacity of this sorbent obtained by the Langmuir equation was found to be 0.1764 mol/kg. The profound study on the parameters affected the extraction properties of the HPMSP doped mesoporous silica towards other metal ions was also performed. The attainment of sorbent capacities for the extraction of these ions was achieved, provided that pH of metal solution was greater than 3 and the metal solution ‘contained NaNO3 salt. The extraction of metal from mixture solution of these three metal ions demonstrated the excellent capacity and the high selectivity of such silica to the extraction of Fe (III) ions. The Langmuir plot gave maximum Fe (III) extraction capacity of the sorbent equal to 0.1825 mol/kg. The reusability of this silica was also established without any decrease in its performance. The study of kinetic extraction revealed the rapidity of the metal extraction process of the sorbent. The application of the HPMSP doped mesoporous silica for the removal of various metals from different wastewater samples was also achieved with satisfactory results.
DOI: 10.14457/cu.the.2005.1887
title: The difference NEF and GAG-SPECIFIC CD8+T lymphocyte responses in control of HIV-1 infectiob in Thaipatients

description: CD8⁺ T lymphocytes are believed to play an important role in the control of Human Immunodeficiency Virus (HIV) infection. Recent studies showed that specificities of CD8⁺ T lymphocytes might have an effect on efficiency of protective immune response. We therefore screened HIV-1-specific CD8⁺ T lymphocytes in 35 HIV-1-seropositive Thais with different level of HIV RNA and in 11 high risk HIV-1-seronegative Thais and their HIV-1-seropositive partners using of Nef and Gag peptides based gamma interferon-enzyme-linked immunospot (ELISpot) assay. In addition, we analysed the amino acid sequences of relevant HIV proteins in non-responsive subjects to study HIV escape mutation. The results demonstrated that the most frequently recognised peptides and the strongest responses were located in Nef, followed by p24 Gag, p17 Gag, and p2p7p1p6 Gag, respectively. There are 30 subjects (85.7%) responded against Nef protein and there are 16 subjects (45.7%) responded against Gag protein. However, neither the breadth nor the magnitude of HIV-1-specific CD8⁺ T lymphocyte responses correlated with plasma viral load. In subgroup analysis, there was no significant difference of responses among individuals with different HIV RNA load. In subjects whose the responses could not be detected had amino acid mutations either within epitope or in the flanking region. However, in case of the discordant couples, we found the different antigenicity recognition against Nef protein. One high risk HIV-1-seronegative subject had vigorous responses against Nef 7, Nef 8, and Nef 9 whilst their partner responded against Nef 9, Nef 14, and Nef 15. These results may indicate that the CD8⁺ T cells specific for Nef 7 and Nef 8 peptides play a critical role in control of HIV-1 infection.
DOI: 10.14457/cu.the.2005.1888
title: A modified genetic algorithm with sampling technique for distillation sequence synthesis

description: A number of chemical engineering optimization problems generally involve highly nonlinear function, which contains numerous local optima in the feasible area. These problems are very difficult to solve and to obtain the global solution. Genetic algorithm (GA) is an optimization method widely used to solve complex optimization problems because GA can successfully solve these difficulties. Moreover, GA is easy to implement. However, GA has some shortcomings that are premature convergence and weak exploitation capabilities. The major reason of its drawbacks causes initial population lacking uniformity properties. In this work, we develop a new efficient genetic-based optimization algorithm by introducing sampling techniques to select a good set of initial population. These are Latin hypercube sampling (LHS), Faure sequence sampling (FSS), and Hammersley sequence sampling (HSS). The performance of the proposed algorithms and a simple genetic algorithm (SGA) is compared in terms of solution quality and speed of convergence to the global optimum through several complex optimization problems and a case study. The case study involves distillation sequence synthesis of methanol/water system. The objective of this problem is to find the suitable sequence and operating points providing a maximum profit. From the results, with the same parameters, our proposed techniques provide a better solution than SGA and/or converge to the global solution more than four times as fast as SGA.