bluuebunny/crossref_metadata_2025 huggingface dataset:
Expatriate management, absorptive capacity of knowledge, and subsidiary performance : the case of Japan-based multinational companies in Thailand and Singapore
Authors:   , Ogushi Wataru
Published: September 2023

The impact of expatriates on knowledge transfer in foreign subsidiaries has been a focus of research on knowledge management in multinational companies (MNCs). This study combines knowledge-based view, the concept of absorptive capacity, and studies on expatriates literature’s approach to examine the effect from expatriates on transfer of two kinds of MNC’s knowledge (i.e. technological knowledge and marketing knowledge). This paper also analyzes the impact of knowledge absorptive capacity on subsidiary performance to examine how expatriates affect subsidiary performance by knowledge transfer. This study ran analysis of 33 subsidiaries of Japan-based firms in Thailand and Singapore over a 16-year period. Results of analysis indicate that the composition of expatriates in subsidiary workforce 1: promotes absorptive capacity on technological knowledge of subsidiary, but 2: hinders absorptive capacity on marketing knowledge of subsidiary. In addition, absorptive capacity of two kinds of knowledge in subsidiary 3: does not gain subsidiary performance by working separately, but 4: gain subsidiary performance by working together. The implications for expatriate management study and knowledge transfer literature are discussed.
Surface modification of microcrystalline cellulose from parawood sawdust via mechanochemical process for reinforcement in polypropylene composites
Authors:   , Chuayplod Patcharaporn
Published: September 2023

The objective of this study is to prepare and modify parawood microcrystalline cellulose (PW-MCC) for applying as reinforced material for polypropylene composites. PW-MCC was prepared from parawood sawdust using acid hydrolysis method with pulp to acid ratio at 1:15 and temperature at 80oC for 2 hours. The obtained PW-MCC exhibited the cellulose type I with CrI at 60%. Moreover, PW-MCC had higher thermal stability than parawood sawdust. PW-MCC was further modified with various types of coupling agent such as maleic anhydride-grafted-polypropylene (PP-G-MA), organosilane, and acid chloride. Vinyltrimethoxysilane and three different acid chlorides such as benzoyl chloride, hexanoyl chloride, and lauroyl chloride were used to modify PW-MCC under mechanochemical method using planetary ball milling at ambient temperature. The optimized condition for each modification and properties of modified PW-MCC were studied and characterized. The functional group from FTIR and surface composition from XPS of silane treated PW-MCC confirmed the chemical bonding between PW-MCC surface and silane coupling agent. The esterified cellulose presented carbonyl stretching of ester peak at 1740 cm-1. Then, PW-MCC and the modified PW-MCC were applied to prepare polypropylene composites at 5-30 wt% loading content without a compatibilizer using an internal mixer for compounding. The compound was fabricated into specimens by injection process. The results of the PP composites revealed that PW-MCC was an effective reinforcing material. The modified PW-MCC enhanced compatibility between PW-MCC and PP matrix resulting in an increasing of mechanical properties, water resistance, and thermal stability of PP composites. Besides, the type of coupling agents was also affected to composites properties. The results indicated that modified PW-MCC with fatty alkyl chain provided a better compatibility than using benzoyl group and organosilane. In addition, using long chain fatty grafted on PW-MCC exhibited a plasticizing effect to composites resulting to the reduction of modulus of the composites. Nevertheless, the suitable content for using modified PW-MCC was 5wt%. Comparatively, cellulose laurate was an effective reinforcing agent for applying in PP composite. Cellulose laurate/PP composite exhibited an increasing of elongation at break and impact strength at 21% and 23%, respectively. In addition, water resistance was increased approximately 80% and thermal stability at Td50% was shifted from 431 to 462oC with char residue at 4.23% which was higher than those of the PW-MCC/PP composites.
Global well-posedness of reaction-diffusion equations with non-radial kernel function
Authors:   , Suechoei Apassara
Published: September 2023

In this thesis, we study the following reaction-diffusion equation:[Equation] where f is a continuously differentiable function on R , α > 0 is a constant, [sumbol] is a continuous function and is non-radial kernel function. We establish the corresponding comparison principle. Then, we prove the local existence and uniqueness result based on the monotone iteration sequence technique. Finally, certain sufficient conditions on the local nonlinear term that guarantee the existence and uniqueness of global solution are specified.
Boundedness of green operators for nonlocal equations on weighted lebesgue spaces
Authors:   , Nuntajittanond Itthinat
Published: September 2023

In this research. we establish the local existence and uniqueness of solutions for the Cauchy problem of the nonlocal equation of the form ∂ₜU(x.t) = ∫R n J(x.Y)U(Y,t)dY – U (x.t) + (In(e + I x I2)) U p (x,t) where p > 1 and ∂ > 0 are constants. In this research, the kernel / of the nonlocal term may not radially symmetric. We investigate the Cauchy problem on weighted Lebesgue spaces with a logarithmic weight. One of the most important results in this thesis is the boundedness of the corresponding Green operator on the weight Lebesgue spaces. We also establish the local well-poseduess of the problem.
F-CS-Rickart Modules
Authors:   , Kaewwangsakoon Julalak
Published: September 2023

Let M be a module over a ring with identity and F be a fully invariant submodule of M. A module M is an F -CS-Rickart module if ⁻¹(F) is an essential submodule of a direct Summand of M for any  ∈ End (M). In addition, M is an F - dual – CS – Rickart module if  (F) lies above in a direct summand of M for any  ∈ End (M). In this dissertation, some properties and characterizations of F – CS–Rickart modules and F –dual-CS– Rickart modules are investigated. Moreover, we prove that any F –dual-CS– Rickart modules and F -dual-CS-Rickart modules can be written as a direct sum of two submodules such that one of them relates to F and the other one is a CS-Rickart module (dual-CS-Ruckart module). Furthermore. we study F-CS– Rickart modules when they are projective modules. In particular, we explore Z (M)-CS-Rickart modules, Z₂ (M)-CS-Rickart modules and Z* (M)-CS-Rickart modules.
General pseudo-polynomials in FQ((1/X))
Authors:   , Meesa Rattiya
Published: September 2023

In this thesis, we study the integer-valued functions and pseudo-polynomials over a finite field. We establish explicit shapes of them and prove that the set of all pseudo-polynomials is an integral domain that is not a unique factorization domain. Difference and higher order differences of integer-valued functions and their properties are also presented.
Selection problems in O-minimal structures
Authors:   , Sokantika Saronsad
Published: September 2023

In this dissertation, we improve the Definable Michael's Selection Theorem in o-minimal expansions of real closed fields. Then applications of this theorem are established; for instance, we prove the following statement: Let be an o-minimal expansion of and T be a definable set-valued map where n = 1 or m=1. If T has a continuous selection, then T has a definable continuous selection. Moreover, we prove the statement: Let be an o-minimal expansion of a real closed field and be a closed subset of Rn. If T: E --> Rm is a definable continuous set-valued map and T is bounded for each in the boundary of E, then T has a definable continuous extension.
Clifford Algebra-valued Segal-Bargmann Transform
Authors:   , Eaknipitsari Sorawit
Published: September 2023

A classical Segal-Bargmann transform maps square-integrable functions on R to holomorphic square-integrable functions on C with respect to some Gaussian measure. In this work, we extend the classical Segal-Bargmann transform to functions taking values in a Clifford algebra. We establish that in this setting, the generalized Segal-Bargmann transform is a unitary isomorphism mapping Clifford algebra-valued square-integrable functions on Rⁿ with respect to some Gaussian measure to monogenic square-integrable functions on Rⁿ⁺¹ with respect to another Gaussian measure. We also discuss about the differential and multiplication operators in the monogenic functions space as well as certain properties of their domains.
Designing packing boxes to minimize number of box types
Authors:   , Laisupannawong Teeradech
Published: September 2023

In a product packing procedure, many types of packing boxes may be used if a factory has several kinds of goods or products. The cost spent for many types of boxes is added to the manufacturing cost. However, it would be more efficient in the aspects of the cost reduction and the production management if we can design reasonable box sizes and can minimize the number of box types for packing goods. In this work, we propose a heuristic rectangular box design algorithm for packing each kind of rectangular goods when the number of goods per box is given. The objective of this algorithm is to design the rectangular boxes with the shapes close to cubes as much as possible under the given bounds. Furthermore, we propose a heuristic method and an integer linear programming model for minimizing the number of types of packing boxes. A smaller box could be substituted by a larger one only when the percentage change on each size of both boxes (with respect to the larger box) does not exceed a given value. Example problems are given to illustrate the use of the proposed heuristic and model.
RADIATION DOSE AND IMAGE QUALITY IN CHEST REGION USING SINGLE- AND DUAL-ENERGY CT: PHANTOM STUDY
Authors:   , Jutawiriya Taninchai
Published: September 2023

Chest CT examinations are routinely performed by using single energy protocol (SE). As CT had been evolved by using dual energy protocol (DE), the patients with underlying lung nodules or pulmonary nodules will be followed up by CT examination several times. The purpose of this study is to study the radiation dose and image quality between single-energy CT (SECT) and dual-energy CT (DECT) protocols in chest phantom at King Chulalongkorn Memorial Hospital. The Lungman Kyoto Kagaku phantom inserted by five simulated lesions of various diameters was scanned by dual-source CT system (Somatom Force, Siemens Healthineers). The acquisition protocols consist of single-energy and dual-energy modes with varied tube potential. Radiation dose is determined in terms of CTDI volume (CTDIvol), Dose Length Product (DLP) and effective dose. Image noise, CNR and lesion detectability are the image quality indicators in this study. The results of this study show that the mean value of radiation dose in SE at 120 kVp was highest among all acquisition protocols, which results in lower image noise than DE. CNR of DE at 100/Sn150 kVp was greater than 120 kVp, all SE protocols, DE at 80/Sn150 and 90/Sn150. Regarding lesion detectability, in the soft tissue window, the simulated lesions were detected by the observers in dual energy mode as similar to in single-energy mode at 120 kVp. Moreover, in the lung window, all observers can detect the simulated lesions better than in soft tissue window, which results in five lesions were detected in both single- and dual- energy protocols, the same as CT lung CAD software could detect five simulated lesions. Therefore, DECT offers an alternative protocol for lung nodule detection because DECT offer lower radiation dose than SECT (120 kVp), clinical protocol in chest CT examination, in addition to lesion detectability DECT is similar to 120 kVp. In contrast, the image noise of DECT is higher than 120 kVp that affect the interpretation of radiologist. Therefore, DE protocols can be selected under the justification of qualified CT radiologist with the optimal protocol in chest CT examination.
Gold nanoparticles in CLP model and mechanism in bone marrows derived macrophages cell for sepsis severity attenuation
Authors:   , Taratummarat Sujittra
Published: September 2023

Sepsis is still a major worldwide- public health problem as a leading cause of the high mortality rate condition. Sepsis is the inflammatory condition in host due to bacterial infections. Sepsis severity depends on the individual's immune responses and the organism virulence factor. The current strategies for sepsis treatment are based, mainly on, symptomatic treatment with antibiotics. However, the adjuvant therapy in sepsis is interesting. Gold nanoparticles are anti-inflammatory drug from the ancient time which is still currently used for the treatment of rheumatoid arthritis. Thus, we hypothesized that gold nanoparticles could be effective in reducing an inflammation in sepsis and testes in bone marrow (BM)-derived macrophages (in vitro) and cecal ligation and puncture (CLP) mouse model (in vivo). After treat with gold nanoparticles, the pro-inflammatory cytokines (TNF-α, IL-1β and IL-6) was reduced in both in vitro and in vivo. But, the anti-inflammation cytokine (IL-10) was increased in vitro but decreased in vivo. However, CLP mice showed the higher survival rate with gold nanoparticles treatment. the bactericidal property and the M2 macrophages induction property of gold nanoparticles are also demonstrated. In conclusion, gold nanoparticles attenuated sepsis through the immune modulation and bactericidal activity. Further studies on the mechanisms and the translation to patients are interesting.
Effects of genistein on oxidative stress and inflammation in acute pancreatitis mice
Authors:   , Sriko Jumlongluk
Published: September 2023

Genistein (GEN), the most abundant isoflavones in soy, has similar structure to human estradiol. It has been reported the potent properties of GEN on antioxidant and anti-inflammation. The aim of this study was to investigate the effects of GEN on oxidative stress, inflammatory, and histopathology in acute pancreatitis induced by L-arginine in mice. Male ICR mice were randomly divided into 4 groups (6 mice in each group). Control (Con) group: mice were injected with 2% dimethyl sulfoxide (DMSO) once daily for 4 days, via IP. Acute pancreatitis (AP) group: mice were injected 2 times (1 hour interval) of 350 mg/100 g body weight L-arginine which dissolved in 0.9% normal saline to induce acute pancreatitis. AP + low dose genistein (LG) group: mice were received 10 mg/kg GEN, while AP + high dose GEN (HG) group: mice were received 100 mg/kg GEN, dissolved in 2% DMSO administered by IP injection 2 hours before the induction of L-arginine, then daily injection of GEN for 3 days. Body weight change was compared between at the beginning and the end of study. Serum and pancreas were collected 72 hours after induction of L- arg. The result showed that, low and high doses of genistein were able to attenuate severity of acute pancreatitis which characterized by restored body weight loss, decreased serum AMY, inflammatory cytokines (IL-6, CPR, and MPO), pancreatic MDA, and decreased histological damage. In the present study increased understanding of the effects of genistein on oxidative stress, inflammation as well as pancreatic histopathology in L-arg induced acute pancreatitis mice.
Surface proteomics of Leptospira interrogans serovar Pomona
Authors:   , Thaibankluay Praparat
Published: September 2023

Leptospirosis is a re-emerging zoonosis of global distribution including Thailand. It caused by pathogenic Leptospira. The pathogenesis is not clear. Surface-exposed proteins (PSEs) are first part for interactions with host cells, immune system and should be potential targets for vaccine development. To date, many researches study only individual PSEs but the studies of surface proteomic is less. The study of surface proteomic will be important information for pathogenesis studies and search for vaccine candidate. This study aimed to identify surface proteomics of pathogenic Leptospira by surface biotinylation and surface shaving using proteinase K that has been used to identify surface proteins in several bacteria combined with Liquid chromatography tandem-mass spectrometry (LC-MS/MS). Intact leptospiral proteins were labeled with biotin (Sulfo-NHS-SS-Biotin). Biotinylated proteins were purified though avidin column before further identification by LC-MS/MS. For surface shaving, Intact leptospiral proteins were treated with proteinase K (ProK) at optimal concentration. The supernatant (shaved protein) were identified by LC-MS/MS. The membrane integrity of leptospires were investigated during experiment in both methods by fluorescence and western blot of periplasmic protein FlaA1 and outer membrane protein OmpL1 or surface-exposed protein OmpL47 in eluted protein sample from biotinylation and in pellet cells of shaving. Proteins were predicted localization by subcellular localization tools including PSORTb, CELLO and SOSUI-GramN. These tools predicted as total 510 outer membrane proteins (OMPs) including 214 OMPs from both of surface biotinylation and shaving method, 66 of which were identified as hypothetical proteins, 222 OMPs from biotinylation only and 74 OMPs from surface shaving method. 8 OMPs. All replicate experiments of both methods identified 8 proteins in common including LipL71 (LIC11003), DUF3383 domain-containing protein/Phage-related protein (LIC12615), LipL45 (LIC11643), LolA outer membrane lipoprotein carrier protein (LIC12545), LipL41 (LIC12966), cheA1 chemotaxis protein histidine kinase-like kinase (LIC13522), FlaA-1 flagellar filament sheath protein (LIC10788), and conserved hypothetical protein (LIC10175). In addition, known PSEs including OmpL1, OmpL47, OmpL37, OmpL41, LipL71 and LigA were found in this study. Therefore, OMPs were found by surface biotinylation and surface shaving. Therefore, this study obtained surface-OMPs information of Leptospira interrogans serovar Pomona. There were at least 66 hypothetical proteins identified as putative surface-exposed OMPs. These proteins are interesting targets to be confirmed as PSEs and further study on their roles in pathogenic leptospires.
Effects of curcumin on oxidative stress, inflammation and apoptosis in L-arginine induced acute pancreatitis in mice
Authors:   , Chingchit Thidarat
Published: September 2023

L-arginine (L-arg) is an amino acid that has been used to induce acute pancreatitis (AP) in mice. Curcumin is an active ingredient constituent of rhizomes of the plant Curcuma longa Linn. It has been used for the treatment of inflammatory conditions and shown to exhibit a variety of biological activities such as anti-inflammatory and anti-oxidant. The present study aims to examine the effects of curcumin on oxidative stress, inflammation and apoptosis in AP. Male ICR mice were randomly divided into 4 groups. 1) Control group, mice will be received i.p. of 1% DMSO as a vehicle. 2) AP group, mice will be received two i.p. of L-arg 450 mg/100 g BW at an interval of 1 h apart. 3) AP + low dose curcumin group, mice will be received curcumin 50 mg/kg bw by i.p. 1 h before L-Arg injection and then once daily for 3 days. 4) AP + high dose curcumin group, mice will be received curcumin 200 mg/kg bw by i.p. 1 h before L-Arg injection and then once daily for 3 days. The mice were sacrificed at 72 h. The pancreatic tissue was fixed for histological evaluation and for NF-kB, apoptosis and MPO immunohistochemistry. The second part was frozen until using protein extraction for 4-HNE examination. Blood sample will be collected for amylase analysis. In AP group, body weight was significantly reduced than control group. While in curcumin group, body weight was maintained. The serum amylase, number of MPO positive cells, NF-kB positive cells, TUNEL positive cells, and 4-HNE expression were increased significantly in AP group when compared with control group, while decreased in low and high dose of curcumin group. Moreover, the AP group showed inflammation, edema and fat necrosis of severe activity of AP. While curcumin low and high dose group showed significantly attenuating histopathological score. However, there is no significant difference between low and high dose of curcumin. In conclusion, curcumin could attenuate AP via anti-oxidant, anti-inflammation and anti-apoptosis property leading to improve pancreatic damage.
Carotenoids and metabolism of the green microalga Chlorococcum sp. 8367RE under stress conditions
Authors:   , Janchot Kantima
Published: September 2023

Green microalgae are one of the natural resources for productions of various and beneficial bioactive compounds, such as UV-screening compounds and carotenoids. This study focuses on the changes of carotenoids and metabolisms in the green microalga Chlorococcum sp. 8367RE under stress conditions. The results showed that stresses by salt, light, drought, and nitrogen starvation affected on alterations of morphological characteristics. Interestingly, size of cells culturing under salt stresses dramatically increased. It should be noted that KCl stress caused the enlargement of cell sizes approximately 5 folds. Carotenoids were identified and quantified by using ultra-high performance liquid chromatography (UHPLC) and mass spectrometry. Three kinds of carotenoids namely violaxanthin, antheraxanthin and lutein were found in algal extracts culturing under control condition. Among these carotenoids, lutein was detected as the highest content 2.24 μg/mg DW. Upon KCl stress, two types of carotenoids; astaxanthin and canthaxanthin, were additionally identified. It is noteworthy that this stress condition, lutein content was very similar level as control while astaxanthin was accumulated 0.12 μg/mg DW. For nitrogen starvation, total carotenoids were decreased. Furthermore, fatty acids, proteins, amino acids, and carbohydrates were analyzed. KCl stress and nitrogen starvation led to the increment of fatty acids contents approximately 2 times (12.79 ± 0.03% DW) and 4 times (28.07 ± 0.79% DW), respectively. Oleic acid was found to be the predominant fatty acid. This study indicates that salt stress resulted in the remarkable alteration of cells morphology and the enhancement of valuable secondary carotenoids and omega-9 fatty acid accumulation. These would be advantageous in health and nutraceutical industries.
Development of technique for screening liquids in unopened bottle using low energy x-ray transmission
Authors:   , Orachorn Parkphum
Published: September 2023

Since August 2006 after the discovery of terrorists’ attempts to explode airplanes with liquid explosives in United Kingdom, each airline passenger is allowed to carry only a maximum of 100 ml liquid in each container and a total of not more than 1,000 ml in carry-on luggage. This measure was adopted to prevent bringing sufficient amount of fuel oil, alcohol, hydrogen peroxide or other flammable and explosive liquids into the aircraft. In this research, X-ray transmission technique was experimentally investigated using low energy X-rays between 13.6 – 43.5 keV emitted from 238Pu radioisotopic source and linear attenuation coefficient of liquids were calculated. The results indicated that the technique could clearly distinguish water, alcohol and fuel oil while its sensitivity is dependent upon radiation energy and diameter of the bottle. Other kinds of liquid are also tested. For bottles or containers having various diameters, multi-energy X-rays may be more practical. This technique is possible to employ the technique for screening bottled liquids contained in unopened bottles at airports.
Comparison of the accuracy of surgical guided template produced from intraoral scan technique and model scan technique for implantation using computer assisted implant surgery
Authors:   , Kiatkroekkrai Prudsaporn
Published: September 2023

Objectives: To compare the accuracy of implant position placed by CAIS technique using surgical guided template produced by intraoral scan and model scan.

Materials and methods: Patients who needed single tooth implant restoration were enrolled in this study and devided into two groups randomly according to the surface scan technique (n=30 each group). Intraoral scans were done using the Trios Scanner (3shape). While, diagnostic casts were scanned by D900L lab scanner (3shape). The templates were design by the clinician using coDiagnostiX software (Dental Wings Inc.). Implant surgery were performed according to fully CAIS protocol. CoDiagnostiX software was used to compare the deviations between planned and placed implant.

Results: Total of 60 implants were treated. The average angular deviation was 2.41°±1.48° and 3.23°±2.09°, the average 3D deviation at platform was 0.87±0.49 mm and 1.01±0.53 mm, while, the average 3D deviation at apex was 1.10±0.53 mm and 1.38±0.68 mm for intraoral scan group and model scan group respectively. Nevertheless, there was no statistically significant difference between groups (P > .05).

Conclusion: The results of this study demonstrated that the accuracy of intra-oral scan technique was similar to model scan technique in all implant dimensions and axis for computer assisted implant surgery.
CD103+ tissue resident memory T cells in oral lichen planus
Authors:   , Amnuaiphanit Phisut
Published: September 2023

Oral lichen planus (OLP) is a chronic inflammatory disease that results from a disorder of infiltrating T cells.  Tissue resident memory T cells (TRM cells) are CD103-expressing T cells that persist within previously inflamed oral mucosa in the long term to provide locally rapid defensive responses against encountered pathogens.  They are also speculated to be associated with some diseases including OLP.  This study aimed to determine the number and the proportion of CD103+ TRM cells in the OLP lesions as compared to the normal mucosa.  Immunohistochemical study of CD3+, CD4+, CD8+ and CD103+ cells in 15 OLP tissues and 15 normal mucosa tissues was performed.  An unpaired t-test, a paired t-test, a Mann-Whitney U test and a Wilcoxon Signed Ranks test were used to analyze the data.  A p-value < 0.05 was considered statistically significant.  The results revealed significant increases in the numbers of CD3+, CD4+, CD8+ and CD103+ cells per area (cells/mm2) in the OLP lesions as compared to the normal mucosa (p < 0.001).  These cells were frequently expressed in the lamina propria rather than the epithelium (p < 0.005).  The proportion of CD103+ cells to CD3+ cells (%) in the lamina propria of the OLP lesions was lower than that of the normal mucosa. (p < 0.001), but this significant difference was not found in the epithelium between both tissues (p = 0.062).  Furthermore, the OLP lamina propria showed lower proportion of CD103+ cells to CD3+ cells than the OLP epithelium (p < 0.001).  In conclusion, this study demonstrates the several-fold increase in the density of CD103+ cells in the OLP lesions that may suggest the association between CD103+ TRM cells and the pathogenesis of OLP.
Microbial conversion of cellulose to sugars by bacterial enzyme
Authors:   , Seneesrisakul Kessara
Published: September 2023

This work studied the conversion of lignocellulosic materials to sugars, the intermediates for bioethanol production, by a bacterial enzyme. Due to the complex structure of lignocellulose, a cellulase enzyme cannot effectively access and hydrolyse cellulose fibers. Various pretreatment processes of lignocellulose have been studied to enhance enzymatic hydrolysis to date. In this work, corncob was firstly studied for microbial pretreatment using three microorganisms including two bacterial strains of Bacillus subtilis A 002 and Cellulomonas sp. TISTR 784 and a fungal strain of Phanerochaete sordida SK7. The results showed that the microbial pretreatment with P. sordida SK7 was the most effective for enhancing enzymatic hydrolysis with approximately 40% improvement, compared to no treatment. Whereas, Bacillus subtilis A 002 was able to hydrolyse some cellulose fraction in lignocellulose but the reducing sugar concentration was very low due to its simultaneously consumption. In the following part, the native cellulase-producing bacteria B. subtilis was developed to produce enzyme at high level using PCR-based cloning technique. Endoglucanse gene encoding from B. subtilis M015 was cloned into plasmid (pFLAG-CTS) and transferred into E. coli JE5505. The clone, named E. coli Glu5, could greatly produce endoglucanase with higher enzymatic activity than that of the native strain, approximately 17 times. Finally, E. coli Glu5 was used for a microbial hydrolysis of soluble cellulose (carboxymethyl cellulose) in a continuous bubble reactor. The results demonstrate the feasibility to consolidate the steps of enzyme production and enzymatic hydrolysis together in continuous system at a low organic loading rate of 5 kg/m3d.
DEVELOPMENT OF POLY(ARYLENEETHYNYLENE)S SYNTHESIS AND APPLICATION AS FLUORESCENT SENSOR
Authors:   , Thavornsin Nopparat
Published: September 2023

In this research, we focus on preparation and sensor application of poly(aryleneethynylene)s. Our work is divided into two parts. The first study relates to the utilization of salicylaldimine-functionalized poly(m-phenyleneethynylene) as a turn-on chemosensor for ferric ion (Fe3+). The second part is the preparation of highly pure poly(aryleneethtnylene)s using Pd/CaCO3 as a heterogeneous catalyst. In the first part, a new turn-on fluorescent probe for ferric ion based on poly(m-phenyleneethynylene salicylaldimine) (PPE-IM) is developed. The preparation of PPE-IM involves post-polymerization functionalization of corresponding polymeric amine, PPE-AM, via condensation with salicylaldehyde. Degree of polymerization of both PPE-AM and PPE-IM are 17 with polydispersity index of 1.5. In aqueous solution, polymeric PPE-IM is hydrolytically stable unlike its small molecule analogue which is gradually hydrolyzed. The weak fluorescence of initial PPE-IM at wavelength 470 nm is greatly enhanced by 300 folds upon the addition of Fe3+. 1H-NMR analysis reveals that the fluorescence enhancement is caused by Fe3+ induced hydrolysis of the imine group. The sensing system shows a detection limit of 0.14 micromolar of Fe3+. In the second part, a commercially available heterogeneous palladium catalyst supported on calcium carbonate (Pd/CaCO3) is studied for preparation of poly(aryleneethynylene)s (PAE)s via Sonogashira coupling polymerization for the first time. The study shows that the use of 10 mol% of Pd/CaCO3 together with commercially available and inexpensive reagents can catalyze C-C coupling polymerization between aryldiethyne and a variety of aryl diiodides/dibromides at 80 oC to provide corresponding PAEs in excellent yields (79-100%) and high degree of polymerization (DP) ranging from 15 to 143 along with polydispersity index (PDI) range of 1.5 to 3.8. The catalytic activity of this Pd/CaCO3 is comparable to the classical heterogeneous, Pd/C catalyst and homogeneous Pd(PPh3)4 catalyst. While Pd/CaCO3 catalysed reaction gives much lower Pd and Cu contaminations in the resulting polymers. In summary, a highly sensitive and selective fluorescence turn-on sensor for Fe3+ is developed from poly(aryleneethnylene)s via post polymerization functionalization (part A). The heterogeneous polymerization using Pd/CaCO3 catalyst is developed for preparation of highly pure poly(aryleneethnylene)s (part B).
SYNTHESIS OF PUERARIN-GOLD NANOPARTICLES FOR TRANSDERMAL DELIVERY
Authors:   , Chanpeng Kwanruen
Published: September 2023

Puerarin (Pur) is herbal medicine that its inflammatory response but low solubility to reduce activity. Thus, the aim of this study was to synthesize q188-kappa-carrageenan@Pur@gold nanoparticles (q188-κ-c@Pur@AuNPs) for enhancing solubility and transdermal delivery. The κ-c was synthesized by quaternization of κ-c with 25% (v/v) q188, and the q188-κ-c @AuNPs was prepared by reducing HAuCl4 into AuNPs by using 25% (v/v) q188-κ-c as reducing and stabilizing agents. The highest degree of quaternization (%DQ) at 21.12% was found q188 addition, which was calculated from 1H NMR. The solubility of the q188-κ-c derivatives was 43.7±0.01%, which higher than κ-c. The size of synthesized q188-κ-c@AuNPs was confirmed by UV-vis, TEM, EDX and DLS, which were found the successfully synthesized with the size 15 nm. A cytotoxic study of Pur loaded on q188-κ-c-@AuNPs derivatives (q188-κ-c-@Pur@AuNPs) were observed, which shown increasing cytotoxicity to CLS cells and non-toxic to normal cells (Wi-38) by MTT assay. In vitro drug permeation was studied by Franz’s cell method. The q188-κ-c-@Pur@AuNPs permeation was investigates by ICP-OES and UV-vis that shown increasing permeation to across cellulose membrane. According to the results, it was suggested that q188-κ-c@Pur@AuNPs can be a good candidate to further development for transdermal delivery applications.
Photooxidation of organosulfur compounds catalyzed by iodo-bodipy derivatives under visible light irradiation
Authors:   , Tangkasemsamran Piyamaporn
Published: September 2023

In this work, iodo-BODIPY derivatives, I-GB, 3I-GB, I-RB, were synthesized and used as photocatalysts for oxidation of organosulfurs such as thiols and thioethers into the corresponding disulfides and sulfoxides, respectively, as well as compared with benchmark photocatalyst, rose bengal. All BODIPY derivatives were successfully synthesized in good yields (36-80%) via condensation reaction between 4-iodobenzaldehyde and corresponding pyrroles, followed by oxidation with DDQ and complexation with BF3.OEt2. Among all synthesized BODIPYs, 3I-GB and 3I-RB showed relatively low quantum yield (0.053-0.054) with high singlet oxygen generation efficiency under green LED suggesting that both of them could serve as good photocatalysts for sulfur oxidation in visible light. In case of 4-chlorothiophenol (7) oxidation, 3I-GB and 3I-RB catalysts drove the reaction completely within 6 hours (92-100%), while other catalysts provided only 4-56% under the same condition irradiating by green LED. Moreover, 3I-GB and 3I-RB can be used as excellent photocatalysts in oxidation of others thiol substrates such as heterocyclic (11, 13), aromatic (7, 9), and benzylic (13) thiols giving the desired disulfides in 79%-quantitative yields. For the oxidation of thioanisole (19), 3I-GB and 3I-RB demonstrated higher catalytic activity comparing to I-GB, I-RB, and rose bengal providing sulfoxide (20) around 80% under green LED irradiation for 24 hours. Unfortunately, other unreactive thioethers such as heterocyclic and aliphatic substrates, were unable to oxidize using our catalysts. For mechanism of sulfur oxidation catalyzed by photocatalysts, we proposed that when BODIPYs is used as catalysts, the reaction proceeds through energy transfer and singlet oxygen is produced during the catalytic circle while the electron transfer process involves in the photooxidation catalyzed by rose bengal.

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EFFECT OF METALLOCENE ELASTOMERS AND SCREW SPEED ON POLYPROPYLENE COMPOUNDS: MORPHOLOGICAL AND PHYSICAL PROPERTIES
Authors:   , Ponhan Supot
Published: September 2023

Polypropylene (PP) which is widely used in automotive industries can replace engineering plastics and metals due to its outstanding mechanical properties, moldability and reduced weight. Some automotive parts such as bumper require higher impact resistance, which is the limited property of PP. The aim of this work is to improve the impact properties with balancing the stiffness-impact properties and the physical properties by blending PP with metallocence elastomer (POE) using a twin screw extruder. The effects of PP and POE type and blending ratio on the PP/POE blends properties and morphology was studied. The results showed that the impact strength of PP/POE blends increased with increasing POE content. However, the balancing of stiffness-impact properties and the physical properties of PP/POE blends were achieved at blending ratio 70:30, especially the well dispersed EOR in PP matrix. In addition, a continuous phase of homopolymer PP (H-PP) as stiffness material could provide the better balancing stiffness-impact properties than copolymer PP (C-PP). Furthermore, the screw speed (400-600 rpm) of extruded affected physical properties, the impact properties increased with decreasing screw speed. From the morphology of blends, an average particle area and aspect ratio of rubber particle in PP/POE blends had a pronounced effect on the physical properties of blends. The PP/POE blends at H-PP/EOR of ratio 70/30 exhibited the good balancing of stiffness-impact properties and physical properties and had a potential to be used as automotive bumpers.
Molecular dynamics of single-wall carbon nanotube wrapped with polypropylene
Authors:   , Panman Wanwisa
Published: September 2023

Nowadays, the nanocomposite materials have been widely used in various applications due to their unique properties such as thermal and electrical properties. Polymer/carbon nanotube (CNT) nanocomposite is one the important nanocomposite materials that are manufactured for improving thermal conductivity and electrical properties of polymers. Unfortunately, polypropylene (PP)/CNT preparation is difficult because of CNT dispersion and aggregation. Accordingly, amylose (AMY) and chitosan (CS) are selected in the present study in order to demonstrate how AMY and CS could diminish such problems by non-covalent modification on outer surface of single-walled CNT using molecular dynamics (MD) simulations. The MD results reveal that AMY wrapped on CNT could induce the binding efficacy of PPs (atactic polypropylene (aPP), isotactic polypropylene (iPP) and syndiotactic polypropylene (sPP)) toward CNT by a significant reduction of distance between the center residue located on each amylose spiral and the adjacent one, especially for iPP and sPP systems. The radius of gyration shows that PPs spirally wrapped around CNT. Additionally, electrostatic attraction is found to be the main interaction inducing PPs to become spirally contacted with CNT. In case of CS modification, it can induce PPs binding but not in a spiral-shape on CS outer surface. The radius of gyration of PPs in CS modified CNT system conflicts with that of AMY model due to it interact with CNT/CS in snake-like shape of electrostatic interaction.
Use of Anionic Surfactant in Regeneration of Spent Activated Carbon
Authors:   , Kallapadee Buch
Published: September 2023

Surfactant-enhanced carbon regeneration (SECR) is a regeneration process that utilizes surfactant solution to dissolve adsorbed organic from spent activated carbon. Sodium dodecyl sulfate (SDS) and methyl ester sulfonate (MES) are anionic surfactants that are used in this investigation. The study is done in 3 steps: sample characterization, regeneration and water flushing step. The proximate analysis of spent activate carbon contains 27.5% moisture, 27.2% volatile matter content, 10% total ash content. The spent activated carbon also contains 18.4% benzene. In regeneration step, the benzene removal by SDS and MES solution were compared. The effect of concentration, solution flow rate and temperature are studied. As expected, the benzene removal increased as the concentration of SDS or MES increased and the benzene removal by MES is higher than that by SDS at the same concentration. However, SDS was easier to be removed in washing step with deionized water than MES.
Conversion of Palm Fatty Acid Distillate to Biojet Fuel over Ni/HY-PdiTiOz Core-shell Catalyst
Authors:   , Homla-or Chanakran
Published: September 2023

Generally, jet fuel is obtained from the refining of petroleum feedstock in order to powering the aircrafts, hence the world is more confronting a problem with increasing air pollution emission. Therefore, biojet fuel is introduced as an alternative way to solve the problem. Biojet fuel can be derived from bio-based feedstock such as palm fatty acid distillate or PFAD. Which is converted via the deoxygenation reaction in order to remove oxygenated compounds, carboxylic and carbonyl groups in the fatty acid molecules then followed by hydrocracking and hydroisomerization reaction. The heterogeneous catalyst is used to convert PFAD into saturated paraffins in the range of jet fuels using the design of core-shell catalyst model to do both steps of deoxygenation and hydroprocessing reaction. In terms of catalyst supports, TiO2 is used as the support in deoxygenation process to produce long chain hydrocarbon. In addition, zeolite is considered as support for hydrocracking process because of its suitable structure and acidity properties. The active metals such as Pd and Ni are also used to develop the efficiency of jet fuel production. In this work, the conversion of PFAD to biojet fuel will be investigated in a continuous flow fixed-bed reactor. The Ni/HYcore-Pd/TiO2shell catalyst will be prepared. During the catalytic activity testing at 425 °C, pressure 30 bar, H2/feed molar ratio of 10, and LHSV of 1.5 h-1 exhibited highest selectivity 48% towards biojet fuel. The effect of increasing space velocity did not give higher selective biojet fuel production due to shorter residence time. The formation of hydrocarbons from fatty acid over core-shell catalyst occurs through an aldehyde and alcohol intermediates further transform to heavier hydrocarbon then subsequently hydrocracking/hydroisomerization to biojet fuel.
Methane Adsorption by Carbon Molecular Sieve Derived from Polycarbonate and Polyaniline
Authors:   , Thawornwatthanasirikul Jakchai
Published: September 2023

The adsorptions of methane by carbon molecular sieves (CMS) were investigated at 35°C and 45°C by volumetric apparatus with the pressure range from 0 to 800 psia. CMS was prepared from polymer precursors such as polycarbonate (PC) and polyaniline (PANI) by carbonization under nitrogen inert atmosphere and activation by CO2 at temperature 700, 800 and 900°C. The yield of CMS is decreased with increasing carbonization and activation temperature. The methane adsorption capacity at 35°C of CMS derived from PC is 2.82 mmol CH4/g. The methane adsorption of the samples from PC is higher than those obtained from PANI for the same carbonization and activation. It is interesting to note that the CMS derived from 700 °C carbonization and activation of PC is higher than the samples obtained from 800 and 900°C carbonization and activation. As expected, methane adsorption at 35°C is higher than that at 45°C for all samples. BET surface area and pore analysis was used to characterize the physical properties and relate to the adsorption capacity.
Effect of oxygen-containing functional groups on methane adsorption by activated carbon
Authors:   , Dheerapreampree Kittima
Published: September 2023

Natural gas has been applied as a fuel for vehicle because it is cheaper and cleaner burning than other fuels. In the vehicle, natural gas is ordinarily reserved by compressing and storing under high pressure at room temperature but this method has several limitations (e.g. low energy density, high weight of tank). Therefore, a porous material with high specific surface area (e.g. activated carbon) is suggested to eliminate the limitations of natural gas storage by compression, natural gas is adsorbed at relatively low pressure and room temperature. The adsorption capacity of activated carbons is related with their physical and chemical surface properties. In this study, bituminous activated carbon was modified by different methods to produce different quantity of oxygen-containing functional groups on activated carbon surface (1) by acid solution or (2) by alkali solution, for studying the relation between oxygen-containing functional groups and the adsorption capacity of methane on activated carbon surface. The physical properties of the activated carbon were Elucidated by using Brunauer-Emmett-Teller (BET) surface analysis. Boehm titration technique and Fourier Transform Infrared Spectroscopy (FTIR) were applied for qualitative and quantitative analyses of oxygen-containing functional groups. The results confirmed the presence of oxygen-containing functional groups on the activated carbon surface consisting of phenolic group, lactone group and carboxylic group. The oxygen-containing functional groups on the surface of activated carbon play an important role on the methane adsorption but the methane adsorption also depends on other surface properties of activated carbon.
Chemical constituents and bioactivities of the leaves and stems of pseuduvaria fragrans
Authors:   , Panidthananon Wongvarit
Published: September 2023

Chemical investigation of the leaves and stems of Pseuduvaria fragrans resulted in the isolation of seven pure compounds, including a new benzophenone C-glycoside named pseuduvarioside and six known compounds comprising (-)-guaiol, (+)-isocorydine, cyathocaline, isoursuline, N-trans-feruloyltyramine and N-trans-coumaroyltyramine. The structure determination of the isolated compounds was carried out by analysis of their UV, HRS-ESI-MS and NMR data in comparison with previously reported values. All the isolates were evaluated for their α-glucosidase inhibitory activity. Only N-trans-feruloyltyramine and N-trans-coumaroyltyramine exhibited strong activity with IC50 values of 3.58 µM and 0.58 µM, respectively, as compared with the drug acarbose (IC50 985.6 µM). Kinetic studies with Lineweaver-Burk plot analysis revealed that N-trans-feruloyltyramine and N-trans-coumaroyltyramine were uncompetitive inhibitors of this enzyme. This study is the first report of the chemical constituents and α-glucosidase inhibitory activity of P. fragrans.
Anatomical and biomechanical factors associated with plantar fasciitis in Thai male conscripts
Authors:   , Harutaichun Pavinee
Published: September 2023

Etiology of plantar fasciitis among novice conscripts is multifactorial. The combination of all potential factors should be included for multivariate analysis to determine the significant predictors. The present study aimed to identify the intrinsic predictors of plantar fasciitis among novice conscripts. Two hundred and seventy healthy male conscripts who were without lower back or lower extremity pain prior to the commencement of military training were participated in this study. Intrinsic predictors which included individual, anatomical, and biomechanical variables were assessed at baseline.  After 10 weeks of training, 113 participants were assessed again and classified as having (n = 71) or not having (n = 42) plantar fasciitis. Multiple logistic regression was used to identify significant predictors. The primary criterion variable was the presence or absence of plantar fasciitis. Current results indicated that the conscripts with poorer quality of movement were two times more likely to exhibit plantar fasciitis (OR = 1.996). The conscripts with more femoral anteversion angle decreased the risk of presenting with plantar fasciitis (OR = 0.720). Regarding individual component, the conscripts with higher body mass index and more stress level increased more risk of plantar fasciitis (OR = 1.238 and 1.110, respectively). In addition, the conscripts with higher physical exercises level before military program reduced the risk of presenting with plantar fasciitis (OR = 0.242). In conclusion, multiple factors – especially individual characteristics and the abnormalities from proximal region (other than foot and ankle) – contributed to the prediction of the development of plantar fasciitis among Thai conscripts.