ISSN: 0125-2364, Online ISSN: 2586-9531

Volume 42 No.1 January - March 2014


P.1-12

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Quorum Sensing, A Communication of Bacteria: Control Mechanism of Pathogenesis in Pseudomanas aeruginosa

ระบบควอรัมเซนซิง การสื่อสารของแบคทีเรีย: กลไกการควบคุมการก่อโรคในเชื้อ Pseudomanas aeruginosa

มณฑล เลิศวรปรีชา และ ญฏารัตน์ สุวรรณมณี

Controlling the work of human and animal cells are associated with cell to cell communication. The mechanism can be divided into two types, first is direct cell to cell contact and second is mediate by mediator molecules which release and bind on to the cell surface molecules, and activate cell functions via signaling pathway. Similarly to mammalian cells, bacterial cells also have a communication system which named as a “quorum sensing system”. Each different bacterial species are able to produce different molecules called autoinducer, which act as a mediator to communication. This quorum sensing system plays an important role for bacteria in respond to environmental condition and control expression of several virulence genes. In this review, the basic knowledge and mechanism of the quorum sensing and the role of quorum sensing which involved to virulence genes expression in P. aeruginosa will be discussed.


P.13-24

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Role of Probiotics for Antibiotic-Associated Diarrhea Prevention and Treatment

บทบาทของโปรไบโอติกในการป้องกันและรักษาอาการท้องเสียที่เกิดจากยาปฏิชีวนะ

เชาวลิต มณฑล

Antibiotic-associated diarrhea (AAD) is a common side effect of antibiotic therapy. AAD results from normal flora destroyed by antibiotics, which causes bacterial pathogens to overgrow. Therefore, probiotics show an important role in preventing and treating AAD. There are many types of probiotics, including bacteria such as: Lactobacilli, Bifidobacterium,Enterococcus, Streptococcus, Escherichia and yeast of Saccharomyces spp. Probiotics have many mechanisms of action. Furthermore, they possess a number of factors which result in different outcomes. Many recent studies indicate that probiotic treatment is an effective medication for the prevention of AAD. However, the efficacy varies by type of probiotic. Also, any severe adverse effects of probiotics are not always reported, except when use in patient with severe acute pancreatitis. The reason is that probiotic therapy has been associated with sepsis, endocarditis and immunosuppression. Patient with severe acute pancreatitis must therefore use probiotics with caution. Nevertheless, overall probiotics are valuable in the prevention and treatment of AAD.


P.25-37

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Moisture Sorption Isotherms of Osmosed-Air Dried Fruits

ไอโซเทิร์มการดูด-คายซับความชื้นของผลไม้แช่อิ่มอบแห้ง

สิทธิโชค เถลิงนวชาติ และ เกียรติศักดิ์ ดวงมาลย์

Moisture sorption isotherm (MSI), a plot between water activity (aw) and equilibrium moisture content of a food at constant temperature, is an important tool to obtain the suitable storage condition for certain food. The shape of MSI is a result of food composition and food structure. Due to high amount of sugar containing in osmosed-air dried fruits, MSI of these products usually present a J-shape. At high relative humidity, the change of crystalline to amorphous form of sucrose leads to a sudden increase in moisture content at high aw. MSI of these products is influenced by various factors in the process of osmosed-air dried fruit. At the same storage condition with high moisture, an increased stage of fruit ripeness resulted in products with lower in aw. This leads to lowering the chance of product deterioration. Partially replacing sucrose with invert sugar lowers the product deterioration. Moreover, methods of drying also affect the MSI shape. Commonly used equation for fitting MSI of osmosed-air dried fruit is Guggenheim-Anderson-de Boer (GAB). The monolayer moisture content (Mo) and the constant “C” depicts the amount of water that strongly bound to other components in product and the shape of moisture sorption isotherm either in sigmoid-shape or J-shape, respectively.


P.38-52

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Characterization of Catalyst by Temperature-Programmed Technique

การวิเคราะห์ตัวเร่งปฏิกิริยาโดยเทคนิคการโปรแกรมอุณหภูมิ

อาทิตย์ อัศวสุขี

Although the catalyst has been studied for over 20 years, the understanding of the altering of catalyst during the reaction and also preparation are rather limited. It has been shown that different catalytic activities and the reaction pathway, and hence product selectivity are pronounced when different catalysts are introduced. The temperature-programmed technique can be used a potentially tool in order to study the characteristic and catalytic activity. The temperature-programmed technique including temperature-programmed desorption (TPD), temperature-programmed desorption of adsorbed i-propylamine (IPA-TPD), temperature programmed reduction (TPR), temperature-programmed reaction (TPRx), temperature-programmed hydrogen evolution (TPHE), temperature-programmed oxidation (TPO), and temperature-programmed sulfidation (TPS) are focused on this article.


P.53-70

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Diacylglycerol Oil: Property and Production

น้ำมันไดเอซิลกลีเซอรอล: คุณสมบัติและการผลิต

ศศิกานต์ กู้พงษ์ศักดิ์ และ ปัทมา ฤาชาฤทธิ์

Recent studies on the nutritional properties and dietary effects of DAG oils, which contain at least 80 wt% DAG, have demonstrated some beneficial effects. Studies on animal and human have revealed a decrease in accumulation of TAG in body fat and liver after intake of DAG oil. The production of DAG oils can be classified by using different catalyst and reaction types. Enzymatic-catalyzed reaction provides several advantages over chemical production using base or inorganic catalysts at high temperature. A mild condition can produce desired high-DAG yield and purity. The most important method for production of DAG involves three reactions: esterification, glycerolysis, and partial hydrolysis followed by esterification. In addition, the separation and purification processes can help to increase DAG yield after the DAG-synthesis reaction.


P.71-83

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Solid Electrolyte Membrane Reactor for Ammonia Synthesis

ปฏิกรณ์แผ่นบางชนิดอิเล็กโทรไลต์ของแข็งสำหรับการสังเคราะห์แอมโมเนีย

สุจิตรา กลิ่นศรีสุข

Ammonia has been industrially synthesized from its elements, H2 and N2, via Haber-Bosch process for almost 100 years. This conventional process performs under high pressure and requires specific catalysts. The highest conversion of Haber-Bosch process is only 10-20% due to thermodynamic limitation. Also, large amount of CO2 is emitted from the use of natural gas as hydrogen source. To resolve the problems, alternative processes have been proposed. Electrochemical process is one of the most promising processes. In electrochemical cells, ammonia is synthesized under atmospheric pressure and without thermodynamic limitation. Comparing with other types of electrolytes, solid electrolytes offer cells with scalable and robust components. Among those solid electrolytes, proton conducting oxide and polymer electrolytes provide the highest rate of ammonia formation. In addition, proton conducting electrolytes have revealed the possibility of ammonia production from water instead of gaseous hydrogen. Therefore, CO2 emission and the overall costs would be significantly reduced. Electrocatalysts are also the important component especially the catalyst for the ammonia formation reaction. It is likely that the sluggish-dissociation reaction of nitrogen molecule on the catalyst surface could be the rate determining step for the formation reaction. In this review, other factors that affect the reactor efficiency including optimized conditions and component requirements are also discussed.


P.84-96

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Properties of Estimators for Generalized Poisson Distribution

สมบัติบางประการของตัวประมาณค่าพารามิเตอร์สำหรับการแจกแจงแบบเจนเนอร์ไลด์ปัวส์ซง

Bunthom Suraporn

Some properties of estimators for generalized Poisson distribution were considered, they were derived the asymptotic properties of the method of moments estimators (MME), maximum likelihood estimators (MLE) and maximum Bayesian likelihood estimators (MBLE). Kumar and Consul (1980) have obtained their expectations up to the first order approximation. They derived asymptotic variances and the covariance of the method of moments estimators, ? and ?.MME? Consul and Shoukri (1984) derived the asymptotic variance and the covariance of the maximum likelihood estimators, ?MLE?, ?MLE?and Suraporn, B. (2006) derived the asymptotic variance and the covariance of the maximum Bayesian likelihood estimators, ??MBLE and ??MBLE . In this paper, some properties of existing estimators, the properties of estimators; consistency, bound and relative efficiency of estimators are considered.


P.97-105

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Karyotypes of Common Lionfish (Pterois miles Bennett, 1828)

คาริโอไทป์ของปลาสิงโตปีกจุด (Pterois miles Bennett, 1828)

วิวรรธน์ แสงภักดี

This research aimed to examine karyotypes of Common lionfish (P. miles). The male and female fish samples were kindly provided by Phuket Costal Fisheries Research and Development. Chromosomes were prepared from kidney cells by gently minced with direct method. Conventional staining and Ag-NORs staining were applied to stain the chromosomes by 20% Giemsa’s solution and 50% silver nitrate. The results demonstrated that it has the number of diploid chromosome (2n) are 48 and fundamental number (FN) are 90 both male and female. Karyotype comprising of 4 metacentric, 6 submetacentric, 32 acrocentric and 6 telocentric chromosomes. The karyotype formula can be deduces as follow: 2n (48) = 4m+6sm+32a+6t. Moreover, the NORs (Nucleolar organizer regions) bearing chromosomes were located on the short arm near telomere of the acrocentric chromosomes pair 6 and use as marker chromosome. The differences of sex chromosomes were not found. These cytogenetic data could be used for further studies of cytotaxonomy and evolutionary relationship of fishes.


P.106-118

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Karyotypic of Golden Little Barb, Puntius brevis Bleeker, 1850 (Pisces: Cyprinidae) from Khon Kaen Province

คาริโอไทป์ของปลาตะเพียนทราย (Puntius brevis Bleeker, 1850) จากจังหวัดขอนแก่น

ณัฎฐา นิธิกุลวรวงศ์ และ วิไลลักษณ์ เครือเนตร

Karyotype analysis of golden little barb (Puntius brevis Bleeker, 1850) from Khon Kaen province was done in the present study. Mitotic chromosome was prepared directly from kidney of specimens after In vivo colchicines treatment. Conventional staining and Ag-NOR banding techniques were applied to stain the chromosomes accomplished by 20% Giemsa’s and 50% silver nitrate solution, respectively. The results showed that the number of diploid chromosome of golden little barb was 2n=50, the fundamental numbers (NF) was 62 in both male and female. The types of chromosomes consists of 4 large metacentric, 4 large submetacentric, 2 large acrocentric, 2 medium acrocentric, 26 meduim telocentric and 12 small telocentric chromosomes. Ag-NOR banding techniques demonstrated that there is 1 pair of NOR exists at telomere region on the short arm of acrocentric chromosome pair 6. The karyotype formula of golden little barb is as follows: 2n (50) = Lm 4 + Lsm 4 + La 2 + Ma 2 + Mt 26 + St 12


P.119-126

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Ectoparasite Infestation of Domestic Dogs in Rural Areas of Chiang Rai Province, Northern Thailand

ปรสิตภายนอกของสุนัขเลี้ยงในพื้นที่ชนบทของจังหวัดเชียงรายทางภาคเหนือของประเทศไทย

พิสิษฐ์ สุนทราวิฑูร, เก่ง เจียมกิจวัฒนา และ งามนิตย์ ราชกิจ

Several ectoparasites on domestic dogs are considered important to public health, particularly fleas, ticks and lice can also transmit pathogens to humans and domestic animals. In this study, a survey of ectoparasite infestation on domestic dogs from eight sub-districts of Mueang Chiang Rai District, Chiang Rai Province, Thailand was performed between June and October 2011. A total of 1,498 ectoparasites belong to three species including Rhipicephalus sanguineus (hard tick: 64.55%), Ctenocephalides felis orientis (flea: 33.85%), and Heterodoxus spiniger (chewing lice: 1.60%). Prevalence of ectoparasite infestation on domestic dogs was 91.25% with the highest prevalence found in Mae Khao Tom and Huai Sak areas (100%) and the lowest in Wiang area (80%). The number of dogs infested were 81.25% (n = 130/146) for Rhipicephalus sanguineus, 53.13% (n = 85/146) for Ctenocephalides felis orientis, and 2.50% (n = 4/146) for Heterodoxus spiniger. The Mean density of ectoparasites per host was 10.26% with the majority being Rhipicephalus sanguineus (7.44%) followed by Heterodoxus spiniger (6.00) and Ctenocephalides felis orientis (5.96). The results demonstrated that the mixed infestations of Rhipicephalus sanguineus and Ctenocephalides felis orientis (46.57%, n=68) were mostly found in domestic dogs. Both species are the major ectoparasites vector of pathogens transmission from domestic dogs to human and other animals in high prevalence areas.


P.127-134

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Effect of Chitosan on In Vitro Growth and Development of Dendrobium formosum Roxb.

ผลของไคโตซานต่อการเจริญเติบโตของกล้วยไม้เอื้องเงินหลวงในหลอดทดลอง

สมพร ประเสริฐส่งสกุล และ หาพิส ปุโรง

Dendrobium formosum seedlings were cultured on solid and liquid VW (Vacin and Went, 1949) media supplemented with commercial chitosan or chitosan from cuttlebone at various concentrations (5, 10, 20, 40 and 60 ppm). The cultures were incubated at 25+2 oC under cool white-fluorescent light at 2000 lux for 16 hours and maintained for 3 months. The results showed that VW solid medium supplemented with 5, 20, 40 and 60 ppm of commercial chitosan or 10 ppm of chitosan from cuttlebone could enhance growth on a fresh weight basis compared to the control without chitosan. Chitosan from cuttlebone at concentrations of 5-40 ppm promoted the number of roots. The shoot length, number of leaves and number of shoots of the seedling treated with commercial chitosan were not significantly different from those treated with chitosan from cuttlebone. Culture in liquid medium supplemented with low concentration of chitosan enhanced seedling growth.


P.135-148

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The Production Development of Tofu from Black Bean

การพัฒนากระบวนการผลิตเต้าหู้แข็งจากถั่วดำ

อรรณพ ทัศนอุดม, วรรณภา สระพินครบุรี และ เมธาวี อนะวัชกุล

The objectives of this study: to find the optimum condition of black bean tofu production for replacing soybean tofu consumption that occurred soybean off-flavor and to study the physical, chemical and microbiological characteristics of tofu produced form black bean. Two levels of sodium sulfate (Na2SO4) quantity (0.66 and 1.0%) and coagulation temperature at 90 and 98?C were studied. Then the % yield of 4 condition treatments were determined. Black bean and soybean tofu attributes were compared by sensory evaluation. The results found that 1% Na2SO4 at 98?C of coagulation temperature was the most optimum condition for black bean tofu production due to the highest of % yield (80%), without soy bean off-flavor and good texture comparing with soybean tofu. Moreover, black bean tofu contained higher content of anthocyanin (2.08%) than that of soybean tofu. Whereas lipid quantity of the former (1.63%) was less than the later. Sensory evaluation between black bean and soybean tofu showed significant difference (P?0.05) in all attributes such as color, specific odor, flavor, texture, and overall preference. Furthermore, these moderately like scores of black bean tofu were higher than soybean tofu.


P.149-158

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Antioxidant and Iron-Chelating Activity of Some Thai Medicinal Plants

ฤทธิ์ต้านอนุมูลอิสระและการเกิดสารประกอบเชิงซ้อนกับเหล็ก ของสมุนไพรไทยบางชนิด

ธวัชชัย นาใจคง, อาซีด หวันยาวา, กฤตพงษ์ เก้าเอี้ยน, จตุพร คงสุขนิรันดร์, สนั่น ศุภธีรสกุล, มาลินี วงศ์นาวา และ นิสิตา บำรุงวงศ์

This study aims to investigate the antioxidant and iron-chelating activity of the ethanolic extract from some Thai herbs used to treat patients with blood disorders; Artocarpus heterophyllus Lam, Randia siamensis Craib., Tarenna hoaensis Pit., Plumbago indica L., Alternanthera bettzickiana Standl., Madhuca pierrei H.J.Lam, Aegle marmelos Correa, Plumeria obtusa Woodson and Cinnamomum bejolghota (Buch.-Ham.) Sweet. It was found that C. bejolgnota shows the highest DPPH scavenging activity with the IC50 of 0.06 mg/mL and total flavonoid content of 270.05?15.84 mg catechin equivalence/g extract. R. siamensis shows the highest iron chelating activity with IC50 0.39 mg/mL. The highest total phenolic content was found in A. heterophyllus at 457.00?49.06 mg gallic acid equivalence/g extract. It is noted that the radical scavenging capacity of the extracts correlate with total phenolic content and flavonoid content. However, iron-chelating activity does not correlate with the antioxidant activity, total phenolic content or flavonoid content. The results from this study support the use of these medicinal plants for the treatment of blood disorders in Thai Traditional Medicine.


P.159-168

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A Comparison of Preservation Methods of Melientha suavis Pierre Branchlets under Low Temperature Condition

การเปรียบเทียบวิธีการเก็บรักษายอดผักหวานป่า (Melientha suavis Pierre) ในสภาวะอุณหภูมิต่ำ

จารุณี จูงกลาง และ จำนงค์ อุทัยบุตร

The preservation of Melientha suavis Pierre, Opiliaceae (pakwanpa) branchlets under low temperature (5?2 ?C) was compared in three tests: C1-uncovered branchlets, T1-branchlets covered with a plastic bag, and T2-branchlets covered with a wet cotton sheet. Weight loss (WL), chlorophyll a and b contents, malondialdehyde (MDA- a product of lipid peroxidation) content, electrolyte leakage (EL), and storage life of the branchlets were determined every three days. The results showed that WL, chlorophyll b content, MDA content, and EL of the branchlets increased with increasing time at 5 ?C. In addition WL, MDA, and EL were lowest, but shelf life was longest in T1 method. The results from this study indicate that the best method in preservation of these branchlets is to keep them in a plastic bag which can maintain them for 6 days.


P.169-175

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The Utilization of Ang-Kak for Color in the Emulsion Fish Sausage

การใช้อังคักเพื่อการเกิดสีในไส้กรอกปลาอิมัลชัน

จุฑามาศ ถิระสาโรช และ เฉลิมพล ถนอมวงค์

Ang-Kak was used to improve color of emulsion fish sausage at 0.3, 0.6, 0.9 and 1.2 percent of fish weight. When compared with control containing 0.3 percent nitrite, it was found that the increasing amount of Ang-Kak resulted in with decreased LUX value (L*) and increased red value (a*). The addition of 1.2 percent Ang-Kak yielded the highest red value (a*) (p<0.05). On the other hand, the addition of 0.3 and 0.6 percent Ang-Kak yielded non-significant difference in firmness (p>0.05) when compared with the control sausage. The use of Ang-Kak showed no effect on moisture content, protein, and fat. However, the fish sausage with 1.2 percent Ang-Kak had the highest fiber content, pH, and overall acceptability, with significant moisture, and pH. The 1.2 percent Ang-Kak fish sausage contained standard level of microbials after 9 days of storage. difference (p<0.05) when compared to the control. After 12 days storage in polypropylene at 4+1 oC, control and 1.2 percent Ang-Kak added products tended to change in color, texture.


P.176-190

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Effect of Glyphosate Applications on Soil Properties

อิทธิพลของการใส่สารไกลโฟเสทต่อการเปลี่ยนแปลงคุณสมบัติของดิน

วภากร ศิริวงศ์

Effects of glyphosate were found on properties of four soil types in a single and repeated glyphosate application. Soil pH was reduced in low clay and organic matter soils, but constant in high clay and organic matter soils after a single glyphosate application. The amount of available phosphorus was decreased in acid soils within three weeks after application and increased in the fourth week. Soil pH and zinc saturation percentage were the significant factors related to phosphorus reduction period whereas the initial content of phosphorus influenced the reduction magnitude. Four weeks after application, the amount of available phosphorus was increased in all soils that relevant to glyphosate dissipation half-life. The value of exchangeable potassium and magnesium was tend to reduce in all soils throughout the experiment, however the significant reduction was exhibited only in acid soils with low zinc saturation percentage. Long-term 4-repeating applications of glyphosate resulted in increasing of available phosphorus in the corresponding time to single application. The accumulation effect on phosphorus content was not found for each repeating applications. The reduction of glyphosate occurred naturally in the experiment. Relationship between soil glyphosate concentration and time after application was corresponded to the first order kinetic equation. DT50 was 16-33 days and was decreased in the repeated application.


P.191-202

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The Effect of 6-Benzylaminopurine and Media on in vitro Culture of Mamao Dong (Antidesma bunius (L.) Spreng. var. bunius)

ผลของ 6-เบนซิลอะมิโนพิวรีนและสูตรอาหารที่มีต่อการเพาะเลี้ยงเนื้อเยื่อ มะเม่าดง (Antidesma bunius (L.) Spreng. var. bunius)

พรทิพย์ เทิดบารมี

The objectives of this study were to investigate the most effective methods for surfacesterilization of shoot explants and the most suitable media for in vitro induction of shoot multiplication and promotion of shoot growth of Mamao Dong (Antidesma bunius (L.) Spreng. var. bunius). The media used for shoot multiplication included Murashige and Skoog (MS) and Woody Plant Medium (WPM) supplemented with 0, 1, 3 and 5 mg/l 6-Benzylaminopurine (6- BAP). For induction of roots, full-, half- and quarter-strength WPM (WPM, ? WPM and ? WPM) were tested. The most effective method for sterilizing the shoots was to soak the intact shoots for 1 minute in 70% (v/v) ethyl alcohol before cutting the shoots from the stem followed by soaking in 2.4% sodium hypochlorite for 10 minutes and finally in 1.2% (v/v) sodium hypochlorite for another 10 minutes. This sterilization process resulted in the highest percentage of shoot explants which were uncontaminated and survived (83.33%). Culture of shoots in MS containing 1 mg/l 6-BAP for 8 weeks produced maximum average number of shoots (2.7) which were 2.85 cm long on average. WPM supplemented with 1 and 3 mg/l were suitable for shoot induction and growth producing the maximum of 2.9 shoots (2.76 cm long) and 2.3 shoots (2.52 cm long), respectively. Culturing the shoots in full-strength and ? strength WPM for 8 weeks produced highest percentage of root induction (10%).


P.203-211

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Analysis of Phenolic Compounds in Wood Vinegar and Smoke from Burning Coconut Shell by Head Space Solid Phase Micro Extraction-Gas Chromatography-Mass Spectrometry

การวิเคราะห์หาสารประกอบฟีนอลในน้ำส้มควันไม้และควันจากการเผาถ่านกะลามะพร้าวด้วยเทคนิคเฮดสเปซโซลิดเฟสไมโครเอกซ์แทรกชัน-แก๊สโครมาโทกราฟี-แมสสเปกโทรเมทรี

ธัญวรรณ กฤษณะพุกต์, วัฒนาพร ลิ่มทองวิรัตน์, สาวิตรี โตกะหุต และ สุวรรณ ไชยสิทธิ์

The investigation of this project was to study the performance of 2 differences SPME fibers that is 75 ?m Carboxen/PDMS and 65 ?m PDMS/DVB. In this analysis, phenol compounds in wood vinegar were found and compared with smoke from burning coconut shell by Head Space Solid Phase Micro Extraction-Gas Chromatography-Mass Spectrometry. It was found that in wood vinegar using Carboxen/PDMS fiber we found 10 types of phenol compounds and using PDMS/DVB fiber we found 14 types of phenol compounds. In smoke from burning coconut shell we found 17 types of phenol compounds equally. Phenol is the most abundant phenolic compounds in both wood vinegar and smoke from burning coconut shell. PDMS/DVB is more effective for the extraction of phenolic compounds than Carboxen/PDMS.


P.212-220

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Synthesis of Hydroxyxanthones and Evaluations for their Acetylcholinesterase Inhibitory and Neurotoxicity Activities

การสังเคราะห์ไฮดรอกซีแซนโทนและการประเมินฤทธิ์ยับยั้ง เอ็นไซม์อะเซติลโคลีนเอสเทอเรสและความเป็นพิษต่อเซลล์ประสาท

Thongchai Khammee, Anan Athipornchai, Wanchalerm Upamaia, Yamaratee Jaisin and Sunit Suksamrarn

A series of hydroxyxanthones has been synthesized and screened for their anti-AChE activity. This led to the discovery of new AChE inhibitors with the highest inhibitory activity of IC50 69.45?0.23 ?M. A neurotoxicity evaluation revealed that hydroxyxanthones represented another class of compound that was non-toxic to the neuroblastoma cells at IC50 higher than 94 ?M.


P.221-234

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Adsorption of Malachite Green in Aqueous Solution by the Thermally Modified Rice Husk

การดูดซับมาลาไคต์ กรีนในสารละลายด้วยแกลบดัดแปรด้วยความร้อน

Manop Sriuttha

The thermally modified rice husk (TMRH) was evaluated as a low cost adsorbent for adsorption of toxic dye, malachite green, from aqueous solution in batch adsorption experiments. The effect of initial dye concentration and contact time of malachite green on TMRH adsorption was studied. The optimal time for malachite adsorption was reached in 1 h. Langmuir and Freundlich isotherms were used to investigate the equilibrium data. The Langmuir isotherm model showed good fit to the equilibrium adsorption data, showing a monolayer adsorption. The maximum monolayer adsorption capacity was found to be 50 mg g-1. The result indicated that TMRH was an adsorbent for the removal of malachite green from aqueous solution.


P.235-247

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Forecasting the Prices of Rubber Smoked Sheets Level 3

การพยากรณ์ราคายางแผ่นรมควันชั้น 3

วรางคณา กีรติวิบูลย์ และ ปรีดาภรณ์ กาญจนสำราญวงศ์

The objective of this study is to construct the appropriate forecasting model for the prices of rubber smoked sheets level 3. The data gathered from the website of Office of the Rubber Replanting Aid Fund during January 2004 to December 2012 of 108 values are used and divided into 2 sets. The first set has 102 values from January 2004 to June 2012 for constructing the forecasting models by the methods of Box-Jenkins, damped trend exponential smoothing, simple seasonal exponential smoothing, combined forecasts that weighted by the least squares method, and combined forecasts that weighted by the proportion of the value in the eigenvector from the principal component analysis. The second set has 6 values from July to December 2012 for comparing accuracy of the forecasts via the criterion of minimum root mean squared error (RMSE). The result shows that the most accurate method is the combined forecasts that weighted by the least squares method.


P.248-261

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Minimum Number of Edges whose Removal Gives a Planar Graph

จำนวนเส้นเชื่อมน้อยที่สุดที่ลบออกจากกราฟเพื่อให้ได้กราฟระนาบ

Weenakorn Leosanurak and Keaitsuda Nakprasit

Let Ce(G) be the minimum number of edges whose removal from a graph G gives a planar graph. We investigate Ce(G) for complete graphs and complete k-partite graphs.