cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.14457/cu.the.2008.1633
title: Identification of non-coding RNAs in Mycobacterium Tuberculosis genome using combined computational approach

description: Nowadays it has already been known that non-coding RNAs (ncRNAs), which are not translated to proteins, play important roles in cellular processes including regulatory functions. In order to identify putative ncRNAs of Mycobacterium tuberculosis, genome-wide screening by using computational approach is applied. Although the efficiency of currently available programs is limited, combined approach was the method of choice. New workflow development was required. The core program, RNAz, of the workflow was integrated with TBA. By testing the workflow with Escherichia coli genome, it was however, observed that TBA generated a large number of false positives by generating missing alignment. This problem is challenging. In order to solve this, new genome wide alignment protocol was developed by combining BLAST search and MAFFT multiple sequence alignment. Evaluating this with E. coli ncRNA prediction, it can improve sensitivity of RNAz results from 0.54 to 0.84, precision from 0.37 to 0.56 and reduce time to calculate from over 6 hours to 70 minutes. Therefore, this protocol was used, instead of TBA, in M. tuberculosis ncRNA gene identification, resulting 61 predicted loci. Based on M. tuberculosis H37Rv ncRNA annotation, 33 predicted RNA loci were located in ncRNA gene region. Other loci were mapped with promoter and terminator prediction. There were 22 loci which had transcription signal and only a locus had double transcription signal. By sequence similarity search, there were 3 loci which matched with two known RNA sequences, ykoK and SRP, in database. The ykoK element is a reglatory element of divalent cation-related genes and SRP involves in protein translocation in cell. Resuling candidate putative loci were considered as putative ncRNAs for further experimental verification.
DOI: 10.14457/cu.the.2008.1634
title: Inhibition on certain food-borne bacteria in yoghurt by nisin-producing Lactococcus lactis WNC20

description: The inhibitory effect of Lactococcus lactis WNC20 (Ll. 20), a nisin producing lactic acid bacteria, on food-borne bacteria was investigated by testing in yoghurt as a food model, as compared to commercial starter, LC. Experimental groups comprised of control A (Ll. 20 as starter culture), control B (commercial starter culture, LC), control C (food-borne pathogen), treatment A (Ll. 20 and food-borne pathogen) and treatment B (LC and food-borne pathogen). Starter culture inoculum of ~6-7- log cycle was used for all experiments. After 48 hours, Staphylococcus aureus ATCC25923 was not detected in treatment A after addition either at 2- or 3- log cycle. While, addition of S. aureus at 4- log cycle, S. aureus decreased 2- log cycle after 24 hours of incubation. However, no detection of S. aureus was observed in treatment B after 48 hours. With regard to, Bacillus cereus ATCC1729, Listeria monocytogenes DMST17303, Escherichia coli ATCC25922 and Salmonella Typhimurium ATCC13311, at 2-, 3- or 4- log cycles, were added into milk at the same time as the starter culture. Lis. monocytogenes was not detected in both treatment A and B after 48 hours incubation. B. cereus was inhibited at 16 hours incubation and increased to 5- log cycle at 48 hours in treatment A when added B. cereus at 2- and 3- log cycles. While, addition B. cereus 4- log cycle, it was inhibited after 16 hours and increased to 5- log cycle after 24 hours in treatment A. B. cereus in treatment B was not detected after 8 hours of incubation, added B. cereus starting at 2-, 3- and 4- log cycles. No viable cell of E. coli (&lt;10 CFU/mL) in treatment A was detected after 72 hours, but in treatment B E. coli was inhibited after 48 hours. With regard to, Sal. Typhimurium starting at 2- and 3- log cycles was not detected after 24 hours of incubation yoghurt, and after 72 hours for adding 4- log cycle in treatment A. Whereas, in treatment B Sal. Typhimurium was not detected after 16 and 24 hours for adding 2-, 3- and 4- log cycles, respectively. All experiments found that pH always decreased whereas percentage of total acid always increased throughout the experiment. Nisin Z was also found from yoghurt Ll. 20, which showed inhibition on, Lb. plantarum TISTR850 growth by agar diffusion technique. Therefore, Ll. 20 could be used as starter in Nham preparatAAion in order to reduce food-borne bacteria contamination.
DOI: 10.14457/cu.the.2008.1635
title: Model predictive control for semi-batch reactive crystallization process

description: Reactive crystallization or precipitation is widely used for the production or purification of valuable substances such as catalysts, ceramics, pigments, cosmetics and pharmaceuticals. In the crystallization process, the size distribution of crystals can affect subsequent operations such as filtration, drying and storage. Normally, the objective of the crystallization process is to achieve a specified the average crystal size. This research presents the implementation of a dynamic optimization strategy in a semi-batch reactive crystallization process to determine an optimal operating concentration policy maximizing an average crystals size subject to a product quality constraint, i.e., the requirement of coefficient of variation. Instead of assuming the perfect tracking of the optimal concentration profile, a nonlinear model predictive control (MPC) is applied to track the obtained optimal concentration policy. As feedback information of states at each time step is required in the MPC algorithm, an extended Kalman filter (EKF) is incorporated to provide the estimate of non-measurable states and uncertain kinetic model parameters in the MPC algorithm. Simulation results demonstrate that the average crystal size is increased by 30% compared with the constant feed rate control strategy. The robustness of the semi-batch reactive crystallizer control is improved by the MPC control integrated with the EKF.
DOI: 10.14457/cu.the.2008.1636
title: Molecular structure and electronic properties of porphyrin-oligothiophene-perylene using quantum chemical calculation

description: A new series of compounds consisting of porphyrin (Por) molecule linked to perylene (Per) unit via a thiophenic bridge are designed, namely, Por-Per, Por-Thio-Per, Por-2Thio-Per, and Por-3Thio-Per by varying the number of thiophene ring from 0 to 3, respectively. Structural and electronic properties of those compounds were studied using quantum calculation approach. The method used was validated and found that the B3LYP/6-31G(d) is the optimal one compromising between the accuracy and the computer time required. With optimal structure of Por-Thio-Per, the effect of mono- and bi-substituents R on C3 and R on C4 of thiophene ring was studied. It was shown that significant changes of the torsion angle between the molecular planes of the Por and Per rings were found only for the two bi-substituted derivatives, R = R = OCH3 and NH2, and one mono-substituted derivative, R = H and R = NH2. Noticeable decreases of the HOMO-LUMO energy gap were found only when the mono-substituents are the electron donor groups. In addition, The significant change of the HOMO-LUMO energy gap was also observed as the function of number of thiophene ring. The UV-visible spectra of all proposed compounds cover a broader range, 370-730 nm and characteristics of the Por and Per molecules, which indicate by the absorptions spectra at 372 and 473 nm, remain unchanged.
DOI: 10.14457/cu.the.2008.1637
title: Multi-wall carbon nanotube-polymethyl methacrylate composite for volatile organic compound sensor

description: Development of gas sensor for detecting toxic gas was conducted in this research work. The gas sensor was fabricated from composite materials between multi-walled carbon nanotube (MWCNT) and polymethyl methacrylate (PMMA). The composite was synthesized by the in situ polymerization and fabrication of the sensor by screen-printing method. The objective of this research was to investigate the performance of MWCNT/PMMA composite as a gas sensor for detecting volatile organic compound. Furthermore, the parameters which affected the response and electrical resistance of the fabricated sensor were investigated. MWCNTs content with weight ratio of 2.0, 2.5, 3.0 and 3.5, gas concentration in a range of 500 to 1500 ppm and types of organic gas (methanol toluene acetone and cyclohexane) were experimentally investigated. The experimental results showed that the increased electrical resistance of the composite was attributed to the exposure to VOC gas, with a response time of less than 3 minutes. In addition, an increased in the MWCNTs content oppositely led to a decrease in the sensitivity of the sensors. On the other hand, the sensitivity was increased with an increased in the gas concentration. Finally, the sensitivity of sensor depended on types of chemical vapor due to interaction between gas molecule and polymer matrix.
DOI: 10.14457/cu.the.2008.1638
title: Optimal conditions for the covalent immobilization of lipase from Candida rugosa for the production of biodiesel

description: Biodiesel (fatty acid alkyl ester) is an alternative fuel which is biodegradable, non- toxic and environmental friendly. Recently, lipase catalyzed transesterification has attracted more attention for biodiesel production because of higher purity product and easy separation of biodiesel from the byproduct, glycerol. However, the cost of enzyme remains a barrier for its industrial implementation. Enzyme immobilization provides considerable increase in efficiency and covalent immobilization has been recognized as the method that yields more stability to the enzyme than adsorption. Hence, the aim of this work is to optimize the conditions for the covalent immobilization of Candida rugosa lipase (CRL), which is one of the most frequently used enzymes for industrial applications on the epoxy enzyme carriers, Sepabeads ECHFA. Firstly, the various optimal conditions for the immobilization were investigated. The results were as follows: pH 8, 1.25 M ionic strength, 8 mg/ml enzyme loading at 20 oC for 5 hours, 0.5% (v/v) tween-80 as adjuvant and blocking with 1M glycine for 10 hours. Then, the optimal substrates for transesterification were screened from 14 types of edible plant oils. Seven of edible plant oils showed potential as feedstocks suitable for biodiesel production from their physical properties and the yield of transesterification catalyzed by commercial lipases; Novozyme® 435 and Lipozyme® RMIM. Nevertheless, palm oil represented the most suitable raw material considering the climatic and cultivation conditions. The optimal conditions for the production of biodiesel by transesterification using palm oil as the substrate were determined. The results were: 4 steps additional mode of methanol, three to one molar ratio of methanol to palm oil, 15% of oil by weight, enzyme loading at 40 oC for 12 hours with no additional water required. From these optimal conditions, biodiesel production was 67%. When the above two commercial immobilized lipases were applied to catalyze the reaction under the same condition, 72% and 60% fatty acid methyl esters were obtained from Novozyme® 435 and Lipozyme® RMIM respectively. Finally, the immobilized Candida rugosa lipases were tested for the reusability in both transesterification and hydrolysis. Unfortunately, the immobilized CRL could not be reused after single catalysis of transesterification. However, its hydrolytic activity appeared considerably well maintained up to the 4th cycle. Overall results indicated that biodiesel could be produced by the Candida rugosa lipase covalently immobilized on Sepabeads EC-HFA.
DOI: 10.14457/cu.the.2008.1639
title: Planning system in tomato planting for processing factory

description: This thesis aims to study the planning system in tomato growing for processing factory by applying MRP (Material requirement planning) technique which this technique provides precise control to operations personnel regarding the amounts and timing of deliveries to produce end items. The objective of this research is to develop the system of plantation planning and scheduling in tomatoes planting for processing factory. The analysis of the causes had found that there was no proper plan for work procedure of farming department to monitor the growing of tomatoes which lead to problem in acquiring fruits to meet with plan. By applying MRP concept, the plantation planning is divided into 4 phases to eliminate the problem and obtain the most effective plan. Phase 1 is the planning, the plantation schedule is obtained. Phase 2 contracting phase, staffs or zone controllers look for the growing areas as scheduled in phase 1 and get farmers to sign contract. If the areas signed in the contract is not enough, there will be some more action in phase 4. Phase 3 planted phase, zone controllers and monitors check the discrepancy of timing in planting from phase 2 and there might be a corrective action. The last phase is pre-harvesting, staffs and monitors evaluate the percentage in acquiring of product. The contract for more amount of product might be signed again if there is not enough growing areas signed in phase 2. After implementing MRP concept, the result of this research showed that there is an increasing in percentage of acquiring products from 51 to 71 percent when comparing between the actual fruits delivered and forecasting demand.
DOI: 10.14457/cu.the.2008.1641
title: Polydiaceylene containing amide groups and their chromism properties

description: Amidodiacetylene lipids are prepared from the condensation of 10, 12-pentacosadiynoic acid (PCDA) and diamine compounds in the presence of 1-ethyl-3-(3́-dimethylamino)carbodiimide hydrochloride salt as a coupling reagent. The monoamindodiacetylenes are obtained in moderate yields (47-55 % yield) when using excess amount of diamines. Using the similar reaction with two equivalents of PCDA, the diamidodiacetylene derivatives are obtained in good yields (52-75% yield). The synthesized amidodiacetylene lipids can be dispersed in water by ultrasonication, giving translucent sol. Upon exposure with UV light, the dispersed lipids undergo photopolymerization to generate the desired blue polydiacetylenes (PDAs). The thermochromic properties of the PDAs are observed by UV-Vis spectrometer and photograph recorder. The observation reveals the structural dependence of the color transition temperatures and their reversibility. The PDAs prepared from diamidodiacetylenes with either aromatic ring or aliphatic chain linkers exhibit complete reversibility of the blue-red color transition while those prepared from the corresponding monoamido derivatives display only partial or no reversibility. The diamidodiacetylenes also gave PDAs with higher color transition temperature (70-95 oC) comparing to the monoamido analogues (65-75 oC). The thermochromism of PDAs having cyclohexyl or bis(propylenoxide ethylenoxide) as linkers between the diamide groups is virtually irreversible and has low color transition temperature (25-60 oC). The results suggest that at least two well-developed hydrogen bonds from amide groups are required for complete thermochromic reversibility. This thesis provides useful structural design for controlling color reversibility and tuning color transition temperature of PDAs.
DOI: 10.14457/cu.the.2008.1642
title: Preparation and properties of polylactic acid and cassava starch blends using citrates and formamide

description: Formulation and method for preparation of biodegradable plastics by blending of poly (lactic acid) (PLA) with at least 50% of low cost cassava starch are investigated using a single screw extruder. Formamide and water are tested as a plasticizer for cassava starch to form low crystallinity thermoplastic starch (TPS) while triethyl citrate and tributylacetyl citrate are used as a compatibilizer for the PLA/TPS blends. The tensile strength and DSC thermograms suggest that pure formamide is better than aqueous formamide solution for the preparation of amorphous TPS. The TPS/PLA blends generally have poorer mechanical properties and lower deformation temperature comparing to virgin PLA. The SEM images reveal that there is some phase separation between PLA and starch in the blends, especially at higher starch contents. The interfacial modification of PLA/TPS blends by using tributylacetyl citrate is better than triethyl citrate in promoting the miscibility between the starch and PLA that is important for improving the mechanical properties of the blends to acceptable level. However, increases the used amount of the citrate compatibilizers significantly decrease the deformation temperature of the blends.
DOI: 10.14457/cu.the.2008.1643
title: Preparation of gelatinized strach/polylactide blends

description: Biodegradable polymer blends between gelatinized starches (GS) with polylactide (PLA) prepared at various blends compositions were studied. The effects of starch, plasticizer, and compatibilizer content on the physical, thermal, morphological, and mechanical properties of blend films were investigated. Two types of starches namely tapioca and corn starches were compared; whereas, three types of plasticizers used in the films were glycerol, propylene glycol (PG), and poly(ethylene glycol) 400 (PEG400). In addition, methylenediphenyl diisocyanate (MDI) was used as a compatibilizer to improve the interfacial interaction between plasticized PLA and gelatinized starch phases. GS content was varied from 0 to 40 wt%, while MDI content was differed from 0 to 10 wt% based on the GS content of blends composition. Biodegradation of the blend films was evaluated by soil burial test, and followed by measuring the changes in physical appearance, weight loss, and tensile properties of the films. The results showed that plasticized PLA with 10% PEG400 and GS with 25% glycerol had appropriate physical, thermal, and mechanical properties. The suitable blend composition between gelatinized starches and plasticized PLA (40:60) was the presence of 1.25% MDI, leading to an increase in the tensile properties compared with the film without a compatibilizer due to the interfacial adhesion improvement between two phases, as evidenced by the morphological results. Furthermore, the tensile properties of the films slightly decreased with increasing amount of GS, whereas the biodegradation rates obviously increased. However, the presence of MDI inhibited the biodegradation efficiency of the blend films. These results are in agreement with water absorption isotherm of the films.
DOI: 10.14457/cu.the.2008.1644
title: Preparation of glucosamine hydrochloride from alfa-chitin by microwave assisted acid hydrolysis

description: Glucosamine hydrochloride (GlcNHCl) is a well known neutrapharmaceutical agent prescribed for osteoarthritis patients. Hydrolysis of shrimp shell α-chitin in concentrated hydrochloric acid under elevated temperature is a general method for production of GlcNHCl. To speed up the hydrolysis process, microwave assisted hydrolysis is studied in this work. With microwave irradiation, the hydrolysis is faster comparing to the conventional heating. Only 12 minutes of reaction time is required to complete the hydrolysis when the microwave is utilized while 90-120 minutes is generally required for conventional heating. The reaction typically gave 55% isolated yield with 99-100% pure of GlcNHCl.
DOI: 10.14457/cu.the.2008.1645
title: Preparation of N-acetyl-D-glucosamine using enzyme from Aspergillus fumigatus

description: N-acetyl-D-glucosamine (GlcNAc) is one of the basic constituents of mammal cartilage, which is known to help repair deteriorating cartilage and relieve pain and inflammation in osteoarthritis patients. The preparation of GlcNAc in multigram scale was achieved by hydrolyzing squid pen chitin with crude enzyme from Aspergillus fumigatus. The enzyme was obtained by cultivation of the Aspergillus fumigatus in colloidal chitin minimum media at pH 3.5 and 40 C. The highest chitinolytic activity of 8.0  0.4 U/mL was obtained after 3 days of cultivation. The hydrolysis of milled squid pen chitin (5 g) with the crude enzymes gave N-acetyl-D-glucosamine (GlcNAc) over 80% isolated yield within 2 days. The optimum ratio of enzyme to chitin was found to be 22 U/g chitin and the optimum chitin concentration was 2.5% w/w of the reaction volume. A 100 g scale hydrolysis of squid pen chitin at 45 C and pH 4, adjusted with 2 M acetic acid, with 2.2 kU of enzyme gave GlcNAc in 65% isolated yield after 2 days of hydrolysis. The high purity of GlcNAc (100%) was obtained by precipitation of the crude GlcNAc in absolute ethanol from its concentrated charcoal decolorized aqueous solution.
DOI: 10.14457/cu.the.2008.1646
title: Preparation of sodium chitosan phosphate/zinc oxide complexes for periodontal dressing application

description: Sodium chitosan phosphate/zinc oxide complexes were prepared by mixing zinc oxide powder to sodium chitosan phosphate aqueous solution. Mole ratios of sodium chitosan phosphate to zinc oxide were varied in the range of 1:0.25-2. The possible structure of the metal complexes were characterized by FTIR, XRD, TGA and DSC. Surface morphology was observed by SEM. Hardness was measured to investigate the mechanical property of the complex. Cytocompatiblility was tested with human gingival fibroblast to all complexes using sodium chitosan phosphate as control. It was found that the complex with various mole ratios was feasibly formed by donating lone pair electrons from nitrogen of amine groups, oxygen of phosphate groups and oxygen of hydroxyl groups of sodium chitosan phosphate to water molecules surrounding on the surface of zinc oxide. All complexes with various mole ratios exhibited the metal complex degradation stage in the range of 200-220 °C that did not found in sodium chitosan phosphate. Hardness of the complexes increased as increasing the amount of zinc oxide. For direct contact test, the complexes with sodium chitosan phosphate to zinc oxide ratios of 1:0.25 and 1:0.5 showed biocompatibility as well as the control that was suitable for applying as periodontal dressing whereas, the complexes with mole ratios of 1:1 and 1:2 exhibited cytotoxicity due to large amount of zinc oxide covering the surface of complexes. For indirect contact test, the extracted solutions from all complexes with various mole ratios showed biocompatibility as well as the control.