cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.14457/cu.the.2006.1590
title: Removal of polycyclic aromatic hydrocarbons (PAHs) from contaminated soil using polymeric nanoparticles

description: Polycyclic aromatic hydrocarbons (PAHs) are organic compounds of great concern due to their potential risk to human health and the environment as they are likely bound to soils and difficult to remove. In this study, the amphiphilic polyurethane (APU) nanoparticles made of poly(ethylene glycol)-modified urethane acrylate (PMUA) precursor chains (80-110 nm) were synthesized to use in remediation of PAHs contaminated soil-packed column. Through batch and column tests, the sorption ability of APU nanoparticles under various phenanthrene (PHEN) and benzo(a)pyrene (BaP) concentrations are investigated. The test results supported that the application of APU nanoparticles could be applied to remove PAHs that have he logK[subscript ow] ranges between 4.6 and 6.5, thereby promoted the application of APU nanoparticles to other hydrophobic organic compounds having similar physicochemical properties. The experiment on steady state attainment revealed that sorption kinetic of test compounds onto APU was more rapid than onto soil (24 and 48 hours, respectively). The partition coefficient between soil and water, K[subscript s,w], of PHEN was lower than that of BaP (PHEN=1776+-88 L/kg; BaP=3162+-363 L/kg). By Normalizing K[subscript s,w] using organic carbon content in the soil, logK[subscript oc] of PHEN and BaP obtained from arithmetic equation (PHEN=4.88; (BaP=5.13) yielded parallel results compared to logK[subscript oc] from other studies. The partition coefficient between soil and APU, K[subscript s,APU], suggested that both PHEN and BaP were likely to sorb onto APU nanoparticles rather than sorbed onto soil. The results revealed that K [subscript s,APU] of PHEN was slightly higher than that of BaP (PHEN=0.55+-0.03 L/kg; BaP=0.36+-0.02 L/kg). Mass balance on APU nanoparticles mobility in soil demonstrated that 94% of the particles was recovered from the soil column. The removal of PHEN and BaP from pre-contaiminated soil column evidently supported that greatest recovery of test compounds were obtained regarding 24-hours flow interruption. In low contamination soil column (0.35 mg/kg), approximately 90% and 50% of initially sorbed PHEN and BaP were recovered over the duration of the experiment. In contrast, approximately 29% and 15% of initially sorbed PHEN and BaP were recovered in high contamination soil column (1.75 mg/kg). These results showed that increase in concentration of PAHs in the soil column reduced APU nanoparticles effectiveness and longer duration of the flow interruption should be considered in APU nanoparticles-assisted remediation. The column tests demonstrated that APU nanoparticles could effectively flush PHEN from soil contaminated with low concentration. However, the significant factor that decreased the efficiency of BaP remediation may be due to the sorption of BaP onto APU in column reached its equilibrium slower than that in batch experiment. Therefore, longer duration of flow interruption than 24 hours would tentatively increase the removal efficiency of BaP from the soil.
DOI: 10.14457/cu.the.2006.1591
title: Effects of Malvastrum coromadelianum Linn. extract on second degree burn wound healing in diabetic and non-diabetic rats

description: The present study aimed to investigate the healing effect of aqueous extract of Malvastrum coromandelianum (MC) Linn. Extract on second degree bum wound, generated by 10 second-application of 90 degree celsius hot plate on the selected area of the back of non-diabetic and diabetic rats. Male Wistar rats weighting 250-300 g were used and diabetes was induced by a single injection of streptozotocin in the dose of 60 mg/kg B.W. intravenously into tail vein. Evaluation of wound healing by an estimation of degree of wound healing, measurement of cutaneous blood flow by Laser Doppler Flowmeter, analysis of malondialdehyde (MDA) as indicator of oxidative stress and histological observation were made at day 3, 7 and 14 posts burning. The results revealed that degree of wound contraction in both diabetic and non-diabetic rats treated with MC extract was significantly different from those observed in their respective untreated and NSS-treated groups at day 3, 7 and 14 posts burning. In comparison to their respective control groups, tissue blood flow was significantly increased in MC extract-treated group at all three time points in diabetic rats whereas it was observed only at day 3 and 7 in non-diabetic group.On day 14, histological observation demonstrated a complete re-epithelialization resulting in complete closure of the wound in non-diabetic rats receiving MC extract while epithelialization in MC extract-treated diabetes rats, though better than its control groups, still incomplete. Application of MC extract seemed to reduce the migration of neutrophils in diabetic and non-diabetic rats though with a lesser extent in the former group. In non-diabetic, burn injury significantly increased oxidative stress which was counteracted by MC extract day 3 and 7. However, in diabetic rats antioxidant property of MC was evident only at day 14. In conclusion, the present studies have demonstrated the wound healing effect of the aqueous extract of Malvastrum coromandelianum Linn. On burn wound in diabetic as well as non-diabetic rats. Slower rate of healing was noticed in diabetic rats. An increase of cutaneous boold flow, anti-oxidation property as well as inhibition of the inflammation process in likely top explain, at least, in part, the beneficial effect observed.
DOI: 10.14457/cu.the.2006.1592
title: Feasibility study on the forming of alumina beads and pellets by agar gelcasting

description: The alumina grinding beads are usually formed by a pan granulator method, however it is difficult to form small size beads (1-2mm diameter). This work is focused on a new forming method which uses agar as gelling agent in gelcasting. The mixtures of alumina suspension and agar solution (concentration 1.5-4wt.%) are dropped into cooled oil using a pipette. The shape of mixture becomes sphere by its surface tension. After the mixture transformed to gel, it is separated from cooled oil. Later the gelled beads are dried in air and finally sintered at 1300-1400 degrees celsius. Tellus 46 oil is the cooled oil having the proper viscosity for forming. At 1.5wt.% concentration of agar solution, the shape of drop which is just dropped from the pipette tip is almost sphere. The sphere became better when final agar content increases from 0.25 to 1.0wt.%. However, at concentration [is more than or equal to] 2wt.% the shape of drop became more and more oval with increasing of the agar content. After drying, gelled beads deform more and more when the agar content decreases. The 99% relative density is obtained for the specimen with the final agar content 0.25 and 1.0wt.% prepared from 1.5wt.% concentration of agar solution.
DOI: 10.14457/cu.the.2006.1593
title: Inventory management system : case of fast moving automotive service parts

description: To develop an inventory management for managing spare parts for an automobile manufacturer in Thailand. The development begins with the investigation of existing inventory system and it is found that the system has been ineffective in managing the inventory level and the company presently faces serious problems of shortages and customer dissatisfaction. This study selects nine fast-moving items to demonstrate the mechanics of the proposed system. The data observed in the years 2004 and 2005 are utilized to determine the system parameters and the performance of the resulting system is assessed by simulating the situations under the new system against the actual operational data experienced over the year 2006. The new system require that the demand patterns are carefully examined and suitable forecasting techniques are then selected correspondingly. The system testing indicated that the selected forecasting methods in most instances perform better than the existing one and result in lower forecast errors. In managing inventory, two continuous review models are proposed; the reorder point model and the min-max model. The results reveal that both models likely lead to a dramatic reduction in backorder quantity, and a significant improvement in the fill rate, thereby significantly increasing customer satisfaction. However, with greater safety sock required the two model are associated with higher cost than the present situation.
DOI: 10.14457/cu.the.2006.1594
title: A study of RFID application for improving the installation process of precast concrete panels in a housing project

description: Two types of information, namely; related jobsite information along the process and feedback information have been found as essential elements for construction process improvement. In current practices, construction process has faced barriers in obtaining these two types of information. To overcome this problem, the new information system is proposed, namely; Radio Frequency Identification (RFID) system which consists of RFID as an automatic identification and data collection device integrated with database. Precast concrete installation process in housing projects has been selected to be a case study. The research had been initiated by reviewing related literatures and conducting field observations. The results of these initial studies are utilized as a basis in constructing the conceptual model of RFID application in precast installation process. The conceptual model is then realized by exploring the RFID characteristics and developing the prototype of RFID system afterwards. The exploration of RFID characteristics aims to reveal the basic characteristics of RFID that are essential to be recognized in supporting the proposed conceptual model. The general findings show that the tag orientations, tag positions, distance, interrogation angle, and the presence of other tags affect the RFID performance. The vertically oriented tag performs more superiorly than the horizontal one. The reading rate, the maximum amount of detected tags at once, and the minimum spacing distance between tags tend to decrease as the reading distance increases. The coverage area tends to be smaller when the reader rotates either horizontally of vertically. The design and development of RFID system is a prototype. It aims to enable the involved parties to collect the required data and to access the required information. The RFID system involves pre-input, input, and output modules. The pre-input and input modules collect associated data to the details of concrete panel information, and the information of precast installation process respectively. The output module presents the required information of the precast concrete panel and the information of the installation events. The information of the installation events is presented in forms of table and graphical views to provide simple analysis of the current precast installation practice. The RFID system provides related jobsite information and feedback information which can be used to improve the installation process of the precast concrete panels.
DOI: 10.14457/cu.the.2006.1595
title: Production time loss reduction in an ice-cream factory

description: Ice-cream’s demands are increasing every year. The factory needs improvement in order to support customers’ demands. From identifying the problem, it was found that the factory could not meet the customers’ demands because the ideal production volume was low. This type of volume is 90% of the maximum production volume. Because of long production time per cycle, the ideal volume is low and unable to meet customers’ demands. The main cause effects both production time and production volume is the production time and production volume is the production time loss. Therefore, this study is interested in production improvement. The objective of this study is to reduce the production time losses in the stick line that has the most serious demands. From studying, there are two main loss times in a production process. They are set up time and freezing time. First of all, should collect data, and analyse them by using why-why analysis in order to know the root causes. From the why-why analysis, it was shown there are a number of ineffective procedures in the set up process. These procedures spent a long time. In the freezing process, it uses an unsuitable freezing agent, which takes a long time not only in transferring heat but also getting the appropriate freezing point. After what, plan to improve the set up process and freezing process by applying ECRS technique. This technique is not only improves procedures but also develops helpful equipment. Then, analyse by economic evaluation. From this evaluation, it can conclude that the company should invest only in changeover project. After the implementation, the improved processes can reduce set up time from 6.90 hrs per production cycle to 2.43 hrs per production cycle or about 64.78% while the manufacturing cost can reduce from 148.75 Baht per liter to 123 Baht per liter or approximately 17.31% For that reason, ideal production volumes are increased about 5 times, which are not only can support this year’s demands but also the forecasting’s.
DOI: 10.14457/cu.the.2006.1596
title: การศึกษาผลของการใช้รังสีอัลตราไวโอเลตบีชนิดความยาวคลื่นช่วงแคบและชนิดความยาวคลื่นช่วงกว้างในการรักษาผู้ป่วยโรคด่างขาว

description: การรักษาโรคด่างขาวปัจจุบันมีหลายวิธี การรักษาด้วยรังสีอัลตราไวโอเลตบีเป็นวิธีการหนึ่งที่ได้ผลการรักษาดี ในปัจจุบันได้มีการพัฒนาให้มีเครื่องฉายแสงแบบเฉพาะที่ ซึ่งมีผลโดยตรงกับผิวหนังเฉพาะบริเวณรอยโรค โดยไม่มีผลต่อผิวหนังปกติของร่างกายส่วนอื่นๆ จึงเหมาะที่จะใช้กับผู้ป่วยที่มีจำนวนรอยโรคไม่มากนัก นอกจากนี้ยังไม่เคยมีผู้ทำวิจัยเปรียบเทียบการใช้รังสีอัลตราไวโอเลตบีชนิดความยาวคลื่นช่วงแคบ และชนิดความยาวคลื่นช่วงกว้างโดยใช้เครื่องฉายแสงแบบเฉพาะที่ในการรักษาผู้ป่วยโรคด่างขาวมาก่อน ศึกษาความแตกต่างของการเกิดเม็ดสีผิว โดยการใช้รังสีอัลตราไวโอเลตบีชนิดวามยาวคลื่นช่วงแคบและชนิดความยาวคลื่นช่วงกว้างในการรักษาผู้ป่วยโรคด่างขาว ชนิดเฉพาะที่หรือชนิดที่เป็นทั่วตัว วิธีการทำวิจัย: ศึกษาผู้ป่วยที่เป็นโรคด่างขาวชนิดเฉพาะที่หรือชนิดที่เป็นทั่วตัว 8 ราย โดยผู้ป่วยแต่ละคนจะถูกเลือกรอยโรค 2 ตำแหน่งที่คล้ายคลึงกันในการรักษา แล้วสุ่มเลือกรอยโรคว่าตำแหน่งใดจะรักษาด้วยวิธีใดโดยตำแหน่งหนึ่งจะได้รับการรักษาด้วยรังสีอัลตราไวโอเลตบีชนิดความยาวคลื่นช่วงแคบ อีกตำแหน่งหนึ่งจะได้รักการรักษาด้วยรังสีอัลตราไวโอเลตบีชนิดความยาวคลื่นช่วงกว้าง ทำการฉายแสงสัปดาห์ละ 2 ครั้ง เป็นเวลา 12 สัปดาห์ ทำการถ่ายรูปรอยโรคก่อนทำการศึกษาและทุก 4 สัปดาห์จนครบ 12 สัปดาห์แล้วประเมินผลโดยการเปรียบเทียบร้อยละของการเกิดเม็ดสีผิว โดยแพทย์ผิวหนัง 3 ท่าน หลังจากนั้นจึงนำมาประมวลผลทางสถิติโดยใช้วิธี Wilcoxon signed-rank test การเกิดเม็ดสีผิวในผู้ป่วยแต่ละรายมีลักษณะแตกต่างกัน พบว่าผู้ป่วย 6รายตอบสนองต่อการรักษาด้วยการฉายแสงทั้ง 2 ชนิดไปในทางเดียวกัน เมื่อนำข้อมุลมาวิเคราะห์โดยใช้สถิติ Wilxoxon signed-rank test พบว่า การรักษาด้วยแสงทั้ง 2ชนิด ให้ผลการรักษาไม่แตกต่างกันอย่างมีนัยสำคัญทางสถิติที่ 4 สัปดาห์ (p= 0.157), 8 สัปดาห์ (p = 1.000) และ12 สัปดาห์ (p = 0.564) สรุปผลการวิจัย: การฉายแสงอัลตราไวโอเลตบีชนิดความยาวคลื่นช่วงแคบแบบเฉพาะที่ ให้ผลในการรักษาผู้ป่วยโรคด่างขาวชนิดเฉพาะที่หรือชนิดที่เป็นทั่วตัว ไม่แตกต่างกับการฉายแสงอัลตราไวโอเลตบีชนิดความยาวคลื่นช่วงกว้างแบบเฉพาะที่จึงน่าจะนำมาประยุกต์ใช้เป็นทางเลือกในการรักษาผู้ป่วยโรคด่างขาวได้มากขึ้น โดยเฉพาะผู้ป่วยที่มีรอยโรคจำนวนไม่มากนัก และต้องการลดปริมาณแสงสะสมที่จะได้รับจากการรักษา
DOI: 10.14457/cu.the.2006.1597
title: Sodium/proton exchange in halotolerant cyanobacterium Aphanothece halophytica

description: The halotolerant cyanobacterium Aphanothece halophytica grown under non-stress (0.5 M NaCI) and stress condition (2.0 M NaCI) provided a maximal Na[superscript+]H[superscript +] exchange when the optical density of culture reached 0.5-0.9 (7[superscript th] day). The Na[superscript +]H[superscript +] exchange of Aphanothece was shown to be dissipated by protonophores, namely valinomycin and CCCP. Na[superscript +]H[superscript +] exchange was strongly inhibited by monensin. Orthovanadate and DCCD also inhibited Na[superscript +]H[superscript+] exchange. Amiloride, a Na[superscript +]H[superscript +] antiporterer inhibitor, showed inhibition of Na[superscript +]H[superscript +] exchange. The Na[superscript +]H[superscript +] exchange was sensitive to sodium azide, an ATP formation inhibitor. These results strongly favour the concept that respiratory energy is used for proton efflux and that the resulting proton motive force may be involved in Na[superscript +]H[superscript +] exchange. A role for antiport activity in pH regulation can also explain the activity of Na[superscript+]H[superscript +] exchange over a broad pH range extending to the alkaline condition (pH 5.0-10.0). The cation/H[superscript +] exchange activity was observed when either mono-valent cations Na[superscript +], K[superscript +], Li[superscript +]) or di-valent cations (Ca[superscript 2+] and Mg[superscript 2+]) served as a cation. The K[subscript m] values for Na[superscript +], Ca[superscript 2+], and Li[superscript +] were 23.7, 4.4 and 36.0 mM, respectively, whereas the Vmax values were 15.0, 14.5 and 16.0% fluorescence respectively.
DOI: 10.14457/cu.the.2006.1598
title: Synthesis and complexation study of calix[4]arene containing stilbene and crown ether

description: A series of stilbene-bridged calix[4]arenes were synthesized in high yields through an intramolecular reductive McMurry coupling of bisbenzaldehyde calix[4]arene using high dilution condition and a large excess of TiCL[subscript4] . Tetra- and pentaethylene glycol chains were tethered to the opposite phenolic groups of calix[4]arene to form stilbene-bridged calix[4]arene crown-5 and crown-6 respectively. The presence of stilbene bridge over the calix[4]arene rim effectively prevents the connection of the polyether chains in the cone conformation resulting in the exclusive formation of 1,3 alternate stilbene-bridged calix[4]arene crown product. Comparing to the cone conformation, the 1.3 alternate calix[4]arene crown ethers have greater extractability and selectivity toward Cs[superscript+] . The attempts to construct the crown ethers for trans-isomer of m-stilbene-bridged calix[4]arene from m-trans-stilbene-bridged calix[4]arene have not been successful, yielding only intractable meterials. Extensive conformation analyses and synthesis of non crown analogues revealed that the length of m-trans-stilbene-bridge is so long that force calix[4]arene into a pinched cone conformation in which the hydroxyl rim is too narrow to allow that phenyl ring flip. The results from this work provide a very logical and reliable insight for the synthesis of cone, pinched cone, partial cone and 1,3-altenate calix[4]arene derivatives.
DOI: 10.14457/cu.the.2006.1599
title: Porous silicon nitride synthesis via the carbothermal reduction and nitridation of silica/rf gel composite

description: The synthesis of porous silicon nitride, one of the most promising structural materials for filter at high-temperature applications, from silica/ RF gel composite which was prepared by combining sol-gel and polymerization methods with the use of silica, precursor was investigated. Silica/RF carbon composite was converted into porous silicon nitride via the carbothermal reduction and nitridation. From the results, 3-Amino propyl trimethoxysilane was found to be a suitable silica precursor for the synthesis of porous silicon nitride. It was also found that aging time of silica/RF gel does not affect the porosity of silicon nitride. Solvent exchange with t-butanol and nolar ratio of silicon and carbon that are used in the preparation of silica/RF gel are the major factor affecting in the porosity of silicon nitride. The reaction time for the carbothermal reduction and nitridation is an important factor affecting the agglomeration and sintering of silicon nitride particles.
DOI: 10.14457/cu.the.2006.1600
title: Theoretical study of thiacalix[4]arene derivatives and their zinc(II) complexes

description: The four typical conformers of thiacalix[4]arene and sulfonylcalix[4]arene derivatives have been studied using the density functional theory (DFT) at B3LYP/6-31G(d) level of theory. The most stable conformer is found to be cone for thiacalix[4]arene derivatives and 1.3-alternate for sulfonylcalix[4]arene derivatives in which an intramolecular hydrogen bond plays an important factor for the conformational stability. Effect of solvents, i.e., water, chloroform and dichloromethane on stability of sulfonylcalix[4]arene derivatives has been computer using the CPCM salvation model combined with DFT method. It is found that all solvents are slightly effect to their stability. The interconversion between cone and partial cone conformers found in each derivative has been predicted at B3LYP/6-31G(d) level of theory. It is clearly seen that bridge types of calix[4]arene show a strongly effect to the interconversion whereas the interconversion barrier of sulfonyl (-SO[superscript2-]) bridges of sulfonylcalix[4]arene derivatives is higher than that of sulfur (-S-) bridges of thiacalix[4]arene derivatives approximately twice times. The complexations between zinc(II) ion and the cone conformer of thiacalix[4]arene and sulfonylcalix[4]arene derivatives have been investigated at B3LYP/6-31G(d) level of theory. The result shows that all of complexations are an exothermic process. Furthermore, the complexation between the Zinci(II) ion and thiacalix[4]arene yields the highest energy which results from the metal-ligand charge transfer (MLCT) effect found on its complex. The host – guest complex of thiacalix[4]arene (tatbtc4a) and calix[4]arene (tatbc4a) receptors with a series of carboxylate guest (acetate, oxalate, malonate, succinate, glutarate, adipate, and pimelate) has been studied using the ONIOM(B3LYP/6-31G(d):AM1) method. All optimized structures are carried out by the B3LYP/6-31G(d) single point calculation. The relative stabilities of the tatbtc4a and tatbc4a complexes with carboxylates in order are malonate &gt; oxalate &gt; succinate &gt; glutarate and oxalate &gt; malonate &gt; succinate &gt; glutarate &gt; adipate &gt; pimelate, respectively.
DOI: 10.14457/cu.the.2006.1601
title: Effects of diol molecular weight on properties of benzoxazine-urethane polymer alloys for ballistic armor applications

description: This study aims to develop a light weight ballistic armor from Kevlar (TM)-reinforcing fiber having polybenzoxazine alloys as a matrix. Polybenzoxazine (BA-a), a novel class of phenolic resin, possesses several outstanding properties, for example, ease of synthesis, low viscosity, near-zero shrinkage, lack of by-product upon curing, high thermal stability and high mechanical property. Moreover, the benzoxazine resins can be alloyed with various types of resins because of the various function groups in its structure. In this work, urethane elastomer (PU) at various polyol molecular weights is uded to enchance toughness of the polybenzoxazine and its effects on properties of ba:pu polymer alloys and also the ballistic characteristics of their Kevlar –reinforced composite are investigated. The experiment reveals that the similar curing peaks of the matrices at various polyol molecular weights, with the same urethane mass fraction, in the resin mixtures were obtained. The glass transition temperature increased from 165 degree Celsius of polybenzoxazine to 240-245 degree Celsius in the 70:30 BA:PU system and the degradation tempaerature also increased from 330 degree Celsius to 344 degree Celsius in the same alloy for all molecular weights of the polyol. In addition, the char yield increased when the higher molecular weight of polyol was added. The flexural modulus of polybenzoxazine also decreased from 6.2 GPa to be in range of 2.0-3.0 GPa with 30wt% of PU at every molecular weight of the polyol. Furthermore, the synergism with ultimate flexural strength in 90:10 BA:PU was obtained at all molecular weights used. The firing test suggested that the TDI-polyol (MW 3000) based urethane prepolymer had the suitable chain length for alloying with the benzoxazine resin particularly at the mass ratio of 80:20 BA:PU to yield a composite of best ballistic performance.