cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.14457/cu.the.2007.1849
title: Application of geographic information system to analyses on heavy metal erosional and depositional rate in the middle part of Songkhla Lake Basin, Southern Thailand

description: The aim of this study is based mainly on the scenario that if the middle pat of Songkhla Lake (SKL) becomes shallow and requires excavation, what the lake sediments would be quantitatively, and whether or not the dug sediments will affect to the environment. Additionally, sources of contamination in the concerned catchment area need to be identified in order to protect and remediate the contamination in the future. The study is divided into two fold – viz. rate and amounts of soil erosion from the SKL catchment area, rate and amounts of sediment deposition in lake, and concentrations and distribution of heavy metals in soils, stream sediments, and lake sediments. All of the data were analyzed with the application of geographic information system (GIS). The results of the analyses were shown as several kinds of maps. The important maps are soil erosion map, maps showing distributions and contaminations of heavy metals both in the Songkhla Lake and its catchment area. Results indicate that the maximum erosion has been found in areas nearby the mountains in the west part of the SKL area with the average rate of 26 tons/ha/yr or 1.64 mm/yr. It is also discovered that contamination of heavy metals varies from places to places. However, comparison was made with the agricultural standard, it is found that none of the heavy metal contents in soils are naturally occurred and do not exceed those of the standards for remediation. Only some elements in stream sediments i.e. As and Pb, which have been distributed naturally in the southern part of western highland and mountains, need to be carefully followed up. For the SKL sedimentation, it is discovered that sediments have been deposited at the average rate of about 0.37 mm/yr. The results of heavy metal analyses on SKL sediments reveal that most sediments contain the heavy metals quantitatively lower than those of the Hong Kong standard for lake excavation. Only the very small amount (&lt;0.05%) shows the values higher than the standard. Therefore it is concluded that the SKL sediments can be excavated without any environmental problem and some specific sediment layers can be extracted for industrial proposes.
DOI: 10.14457/cu.the.2007.1850
title: Arsenic, chromium, and copper leaching from CCA-treated wood

description: This study was conducted to determine the potential risks of arsenic, chromium, and copper from the disposal of chromated copper arsenate (CCA)-treated wood when its service life ends. The study consisted of batch leaching tests and lysimeter tests. The TCLP and WET were conducted in batch tests of CCA-treated wood and ash burned from CCA-treated wood. A total of six 2-meter high and 20.32-cm in diameter lysimeters were prepared for the lysimeter test: two lysimeters simulated wood monofills, two simulated construction and demolition (C&D debris landfills, and two simulated MSW landfills. Each set of two lysimeters was identical except for the wood components, which were CCA-treated wood and untreated wood. All lysimeters were fed with simulated rainfall during the rainy season. The quantity of leachate generated from each lysimeter was measured daily and the leachate characteristics were analyzed weekly. The experiment was conducted over a period of six months. The results from the batch leaching tests showed that two of the five wood samples from the TCLP test and three of five wood samples from the WET test leached out arsenic in levels that exceeded the TC and STLC concentration of 5 mg/L. In addition, the leaching of all metals found in ash from burned CCA-treated wood exceeded the TC and STLC limits (i.e., the TC and STLC limits are 5 mg/L for As and Cr, and the STLC limit for Cu is 25 mg/L). The lysimeter study results showed that leachates generated from the CCA-treated wood monofill lysimeters contained significantly high concentrations of Cr, Cu, and As, compared with those of the other lysimeters. The highest average concentrations of Cr, Cu, and As were investigated in the monofill of the CCA-treated wood lysimeter, followed by C&D debris with CCA-treated wood lysimeter and MSW with CCA-treated wood lysimeter, respectively (except for As, for which the concentration in the C&D debris lysimeter was lower than that of the MSW lysimeter). In this study, amounts equal to 10 times the regulated limits listed in the Groundwater Standards for Drinking Purposes in Thailand from the Notification of the Ministry of Industry were used as the criteria to evaluate the potential risks to humans and the environment. It was found that the As concentrations in the generated leachate from all three experimental lysimeters were higher than the criterion of 0.5 mg/L. On the other hand, the average concentrations of Cr and Cu in the leachates from all lysimeter were less than the criteria of 20 and 15 mg/L, respectively. These results clearly illustrate that the appropriate disposal of CCA-treated woods necessitates the appropriate handling of arsenic. It can be concluded that the disposal of CCA-treated wood in a wood monofill, an unlined C&D landfill, or a MSW landfill could result in groundwater contamination.
DOI: 10.14457/cu.the.2007.1851
title: Biodegradation of 17 alpha-methyl testosterone under aerobic and anaerobic conditions

description: To produce an all-male population, a very common practice is to feed the Nile tilapia (Oreochromis niloticus) fry with 17alpha-methyltestosterone (MT)-impregnated food. MT residues in fish feed for the masculinization of Nile tilapia fry may accumulate in masculinizing ponds and be released into natural receiving water. A recent study showed that MT concentration in soils were between 2.8 and 2.9 ng/g for nearly three months after cessation of treatment demonstrating the persistence of MT in soil. The objectives of this study were to investigate the biodegradation of MT under aerobic and anaerobic conditions and isolation of responsible microorganisms. Bacterial seed used was aerobic sludge, anaerobic sludge taken from wastewater treatment plants and sediment taken from a masculinizing pond of tilapia fry. Aerobic and anaerobic biodegradation test suggested that MT was biodegradable. Under aerobic condition, first-order degradation rate constants using aerobic sludge were 1.43±0.12, 0.48±0.04, 0.37±0.01, 0.24±0.17 and 0.36±0.17 day-1, for an initial MT concentrations of 0.3, 1.0, 5.0, 7.0, and 10.0 mg/l, respectively. Under aerobic condition, first-order degradation rate constants using sediment were 0.52±0.02, 0.23±0.04, 0.17±0.02, 0.13±0.01 and 0.10±0.01 day-1 for the initial MT concentrations of 0.3, 1.0, 5.0, 7.0, and 10.0 mg/l, respectively. Under anaerobic degradation, first-order degradation rate constants using anaerobic sludge were 0.19±0.01, 0.21±0.01, 0.28±0.03, 0.19±0.01 and 0.10±0.01 day-1 for the initial MT concentrations of 0.1, 1.0, 3.0, 5.0, and 10.0 mg/l, respectively. Under anaerobic degradation, first-order degradation rate constants using sediment were 0.09±0.02, 0.34±0.01, 0.33±0.01, 0.23±0.08 and 0.09±0.01 day-1 for the initial MT concentrations of 0.1 1.0, 3.0, 5.0 and 10.0 mg/l, respectively. MT-degrading bacteria strain MT 3/10, MT 5/10 and 1/500 were isolated from aerobic sludge. Analysis of 16S rRNA gene sequences suggested that the strain MT 5/10 related closely to Acidovorax sp. RCPCd1 which is in the genus Acidovorax. And the strains MT 3/10 and MT 1/500 related closely to Methylophilus leisingeri strain RCP5 which is in the genus Methylophilus. The activities of both strains were not so effective. After 2.5 days of operation, MT concentrations were left over at 46 % for strains MT 3/10 and 55 % for MT 1/500.
DOI: 10.14457/cu.the.2007.1852
title: Biodiesel production from oil of endophytic fungus

description: Aims of this research were to produce biodiesel from lipid of an endophytic fungus and to investigate the influence of cultivation parameters on lipid production. It was found that time, amount of malt extract, carbon source and nitrogen source affected the lipid production and %unsaturation of triglyceride. The maximum lipid production was at the beginning of stationary phase of the growth. The lipid, produced by the fungus from all cultivation conditions, comprised of about 12% free fatty acid (FFA) while the unsaturated fatty acid component of the lipid depended on the cultivation conditions. The fungus, cultured in MEB, produced the lipid with 53% unsaturated fatty acid. The suitable method for biodiesel production was produced by a two-stage transesterification process. The first stage was acid pretreatment with 1% H₂SO₄, which could reduce the FFA level of lipid of endophytic fungus to less than 1%. The second stage, alkali base catylyze transesterification using 1% NaOH, gave 94.78% of methyl ester content and 97.34% of conversion.
DOI: 10.14457/cu.the.2007.1853
title: Biomarkers for monitoring environmental impacts of Organochorine pesticide residues on freshwater mussels

description: Thailand is known as an agricultural country with more than 53% of the total area. uses of organochlorine pesticdes (OCPs) to control pests have been carried out intensively. Due to their persistence in the field and their abilities to be biomagnified through food chain, the extent of OCPs contamination in ecosystem is crucial for environmental monitoring program. In the study, we used freshwater mussels to monitor the OCPs contamination in a freshwater ecosystem at Khlong 7 canal Rangsit agricultural area. three species of freshwater mussels (Uniandra contradens ascia, Pilsbryoconcha exliis exilis and Hyriopsis (Limnoscapha) deswitzi) and the surrounding sediment were collected during March 2006 – March 2007. the concentrations of OCPs namely HCH, Heptachlor, aldrin and dieldrin, Endrin, Endosulfan, DDT, and methoxychlor were quantified by gas chromatography with micro-electron capture detector (GC-uEDDT). the results showed that low levels of OCPs residues were contaminated in sediment and mussels. the concentrations of HCH, DDT, Heptachlor and Endosulfan were the most prevalent OCPs with the range of 6.93 – 15.33 up/kg in sediment and 19.48 – 68.44 up/kg in mussels. there were significant diffierences in OCPs contamination arnong sampling periods with the highest levels found during June – November. the OCPs residues found in mussel tissue were below the maximum residue limits by the Ministry of Public Health of Thailand. vitellogenin (vtg) in mssel gonad and specific activity of glutathione-s-transferase (GST) in mussel hepatopancreas were determined by ELISA and spectrophotometry, respectively. it was found that the levels of vtg and GST in mussels showed seasonal difference and significantly correlatead with the levels of OCP residues in sediment and mussels. this indicates that the freshwater mussels living nearby the agricultural fiels could potentially be used as sentinel species for environmental contamination of organochlorine pesticides.
DOI: 10.14457/cu.the.2007.1855
title: Characterization of starch debranching enzyme from tuber of cassava Manihot esculenta crantz cv. KU50

description: Starch debranching enzyme (DBE), one of the emzymes involved starch biosynthesis in plant, hydrolyzed the a-1,6 linkages of polyglucans was classified into two types; lsoamylase and pullulanase. DBE from nine moths old cassava tubers cv.KU50 was purified by 60% saturated ammonium sulfate precipitation followed by chromatographies on DEAE-Sepharose and Sephacryl S-200. lsoamylase and pullulanase were 14.6 and 20 folds purified. on sephacryl S-200, molecular weight of lsoamylase and pullulanase were 98 and 175 kDa respectively. on SDS-PAGE, lsoamylase showed 2 major protein bands containing 41 and 34 kDa, and pullulanase showed 3 major protein bands of 54, 46 and 41 kDa. Both lsoamylase and pullulanase had optimum pH at 6.0 while the optimum temperatures for their activities were 70 and 50oC, respectively. pullulanase showed high specificity towards pullulan and law specificity with amylopectin. lsoamylase showed high specificity with amylopectin but could not hydrolyza pullulan. the Km for amylopectin with lsoamylase was 21.14 mg/ml while the Km for pullulan of pullulanase was 39.49 mg/ml. the sulfhydryl reagents such as DTT, GSH and B-mercaptoethanol showed positive effect on CBE, indicating that –SH group involved in DBE activity. lsoamylase was inhibited by Cu2+ and activated by Co2+ while pullulanase was inhibited by Cu2+ and Ni2+ and activated by Co2+, Mn2+.
DOI: 10.14457/cu.the.2007.1857
title: Computaton of force closure grasps from finite contact pont set

description: An object is securely grasped when the grasp achieves force closure. The force closure property indicates that a grasp can balance any external disturbance exerted on the object. This work addresses the problem of form closure grasp synthesis in two novel aspects: the representation of the object by discrete contact points and the need to compute all force closure grasps of an object. This two aspects are very crucial for grasping in an unsupervised workspace. Several algorithms are presented to solve this problem in four specific settings which are classified by the presence of friction and the dimensions of the objects. Empirical comparisons between the proposed algorithms and existing algorithms are conducted. The comparisons focus on speed and accuracy of the algorithms. It is shown that the presented algorithms outperform existing algorithms in both aspects.
DOI: 10.14457/cu.the.2007.1858
title: Continuous demulsification of palm oil in water by low electric field

description: Separation of palm oil-in-water emulsion using electric fields was investigated in this study. The experiments were conducted in continuous flow and batch systems. The vessel is made of acrylic plate having a width of 3.0, a length of 8.0 and a depth of 2.5 cm. The electrodes are made of stainless steel having a width of 2.5 and a length of 12 cm. Oil-in-water emulsion consisted of crude palm oil in water at a concentration of 2%wt and sodium sulfate was used as an electrolyte at a concentration of 3.0 mmol. Electric fields were 2, 4, 6, 8 and 10 volts/cm. In continuous flow system, the emulsions flowed pass through the vessel by micro pump at flow rates of 3.0, 5.4, 11, 16 and 20 ml/min. Experimental results show that application of low electric fields to palm oil in water emulsion increased demulsification phenomena. Oil droplets in the electric field were collided to form larger droplets. In a batch system, the percentage of oil content decreased when higher voltage was applied between electrodes. In a continuous flow system, the percentage of oil content decreased when higher voltage was applied and the emulsion flow rate was low.
DOI: 10.14457/cu.the.2007.1859
title: Development of fluorometric microplate screening for topoisomerase 1

description: Topoisomerase I has been recognized as a biological target for anticancer or antimicrobial agents. The conventional assay of the enzyme for enzyme activity and screening of enzyme inhibitors was typically agarose-gel electrophoresis. The disadvantages of this method were time-consuming and low throughput. Thus, the purpose of this study was to develop assays by using fluorescent dyes and 96-well microplate format to obtain the more simple and rapid method for screening inhibitor. Four fluorescent dyes including Hoechst 33258, Hoechst 33342, Picogreen and Sybr Green I were investigated. From this study, only Picogreen was most effective to separate minimum signal from maximum signal with the Z value above 0.4. Optimal DNA concentration to be used in Picogreen-based assay should be in range of 50-1000 ng/ml to obtain the Z value above 0.4. The time-course study of topoisomerase I activity using Picogreen was performed to compare between gel-based assay and fluorescence microplate assay. The study suggested that the fluorescence microplate assay was more sensitive than gel-based assay. The utility of our assay was comfirmed by mearsuring the effect of known topoisomerase I inhibitors (camptothecin, heparin, quercetin and menadione) and topoisomerase II inhibitors (etoposide and ellipticine). The IC50 values of topoisomerase I inhibitors from fluorescence method were comparable to that from gel-based method, even though the previous assay were higher IC50 value. However, it could not measure the IC50 value of quercetin because of an interference of the fluorescence intensity of Picogreen by quercetin. In this study, ellipticine, an intercalative topoisomerase II inhibitors exhibited inhibitory effect on topoisomerase I was 100% at 20 µM and it also interfere the fluorescence intensity of Picogreen. Tweleve unknown compounds were selected to screen by both assays. From gel-based assay, chelerythrine, sanguinarine, oxostephanine and fagarine could inhibit topoisomerase I at concentration of 50 µM for 41.1±18.9%, 47.7±9.01%, 84.3±23.4% and 106±8.5%, respectively. The limitation of fluorescence microplate assay was inability to detect intercalating agents such as chelerythrine and sanguinarine. In conclusion, we could develop a rapid assay for topoisomerase I inhibitors using Picogreen as fluorescent probes. If the compounds have DNA binding properties, gel-based assay should be used instead of the fluorescence microplate assay.
DOI: 10.14457/cu.the.2007.1860
title: Development of the films as tablet degradation indicator

description: The experiment aimed to design thin film as drug degradation indicator to be placed on the surface of tablets. The approach was to prepare thin films in three layers by using hydroxypropyl methylcellulose as film base. The first layer contained red cabbage extract as a source of pH indicator (anthocyanin). The middle layer contained poly-Nisopropylacrylamide (PNIAAm) acting as thermo sensitive polymeric barrier. The last layer was alkaline layer. The thin film was produced and evaluated at 60ºC, 20%RH as a function of time. The result showed that the contraction of PNIAAm after exposure to high temperature effects the release rate of red cabbage extract through thin film. The plot between red color parameter, a* value and time was used to compare the difference of each thin film formulation. ANOVA and Model Independent Methods (difference factor (f1) and similarity factor (f2)) were used to evaluate the profiles of a*value before reaching the end point. Thin films were further formulated and used as tablet degradation detector of two model drugs, glibenclamide and aspirin. Glibenclamide was characterized for solid state transformation and its effect on solubility. Aspirin was evaluated for the rate of chemical degradation to salicylic acid. The solubility of amorphous glibenclamide was decreased below 0.06 mg/ml after storage at 60ºC, 20%RH for 14 days. While aspirin commercial tablets increased the degradation product (salicylic acid) reaching the limit of 0.3% by weight at 60 ºC, 75%RH after 18 days. The color change in thin film correlated well with the degradation rate of glibenclamide and aspirin tablets and was able to visually observe the change. The results indicated that this indicator system can be tailor-made to produce thin film suited for other drugs in detecting degradation which is due mainly to temperature.
DOI: 10.14457/cu.the.2007.1861
title: Effect of mud invasion on pressure transient obtained from wireline formation tester

description: In this study, a reservoir simulator is used to generate pressure responses from wireline formation tests for single layer homogeneous reservoir, invaded reservoir due to mud invasion, and stimulated reservoir. Then, the well test interpretation software is used to estimate reservoir parameters from the simulated pressure response. A single layer homogeneous reservoir is used as a base case to investigate the effect of probe size and permeability anisotropy ratio. Then, a single layer reservoir with an invaded zone is investigated to evaluate the effect of mobility ratio and effect of radius of invasion. Finally, a single layer with stimulated zone is investigated to evaluate the effect of mobility ratio and effect of radius of stimulated zone. All the investigations are performed to determine whether the results from wireline formation test conducted in particular systems can provide satisfactory information under different reservoir scenarios and tool limitation. The study concludes that for both damaged and stimulated reservoir, the pressure response obtained from the single probe wireline formation test can provide accurate estimate of reservoir permeability. Therefore, the single probe wireline formation test can be readily used in both invaded reservoir and stimulated reservoir.
DOI: 10.14457/cu.the.2007.1862
title: Effect of phosphorus in fertilizer on available cadmium and zinc uptake by sugarcane

description: To enhance sugarcane yield, phosphorus is generally applied to soil in the form of NPK fertilizer. However, phosphorus (P) fertilizer is known as a source of Cd and some other metals. Besides, phosphorus to be uptake to plant may affect the uptake of other ions including Cd and Zn. Therefore, this study aimed to investigate phosphorus in fertilizer on available Cd and Zn in soil and hence in sugarcane. The study was conducted both in field and in pot experiment. In field experiment, soil and sugarcane samples were collected from three areas difference in the range of Cd concentration in soil (&lt; 3, 3-20 and &gt;20 mg Cd/kg) in Mae Sot district, Tak province, Thailand. These areas was applied with 16-16-8 NPK fertilizer at the rate of 50 kg fertilizer/rai in the first month after cultivation and a repeat application of fertilizers was conducted at the same rate in the fifth month. Pot experiment was set up in order to investigate the effect of P in the fertilizer on available Cd and Zn in soil and its uptake to sugarcane under the control conditions at various rates of fertilizer application. The soil used for pot experiment was taken from Cd contaminated areas in Mae Sot district with the range of &lt; 3 mg Cd/ kg. In each experimental pot sugarcane was planted by a piece of mature cane stem as normally practice. The 16-16-8 NPK fertilizer was applied to every experimental pot at rate 0 (control), 50, 100 and 200 kg fertilizer/rai in the first month and the fifth month. Soil and sugarcane samples were collected at the end of the second and sixth months after cultivation, respectively for both field and pot experiment. As expected, the result from field experiment showed that available Cd and Zn in soil were significantly higher (P &lt; 0.05) in the area contaminated Cd at the rate of &gt;20 mg Cd/kg as compared to the other two areas (&lt;3 and 3-20 mg Cd/kg). Consequently, the accumulation of Cd and Zn in sugarcane cultivated in the area of Cd contaminated &gt;20 mg Cd/kg areas was higher than the other two areas. This is because the higher total Cd and Zn concentrations in soil tend to provide higher available Cd and Zn in soil and hence in sugarcane. For pot experiment, the fertilizer application rate showed insignificant affects on the total accumulation of Cd and Zn in soil. In contrast, the different fertilizer application rates affect on available Cd and Zn concentrations in soil and in sugarcane. The results showed that the higher the rate of the fertilizer application, the lower the available Cd and Zn concentration in soil and the lower Cd and Zn concentration in sugarcane. This may be explained by the higher P through increasing fertilizer application rate competed with Cd and hence reduced its uptake to the plant. The results also indicated that concentrations of Cd and Zn were highest in root and lowest in juice for both field and pot experiment.