 |
|
 |
|
|
|
ผลงานตีพิมพ์ในวารสารวิชาการElectrical Conductivity Response of Poly(Phenylene-vinylene)/Zeolite Composites Exposed to Ammonium Nitrateผู้แต่ง: Kamonsawas, J, Sirivat, A, Niamlang, S,  Dr.Pimpa Hormnirun, Associate Professor , Prissanaroon-Ouajai, W, วารสาร:  
|
|
 |
|
|
 |
 หัวเรื่อง:ค่านำไฟฟ้ากับความเข้มข้นของโซเดียม แคลเซียมและแมกนีเซียมในสารละลายดินอิ่มตัวของชุดดินกำแพงแสน ผู้เขียน:ดร.สุนทรี ยิ่งชัชวาลย์, ศาสตราจารย์ , Anuwat Pothinam สื่อสิ่งพิมพ์:pdf AbstractSeveral soil variables are routinely measured in the study of soil salinity. These variables are then used only for classifying soil as being saline. This study examined various relationships between all these variables to gain insight into the nature of salts presence in the field. The relationships will be useful for further study of salt distribution in the area. Agrid of 100 x 100 m2 was laid out on the Kamphaeng Saen soil series (Typic Haplusalfs) in the field of 128 hectares in Kasetsart University, Kamphaeng Saen. Soil samples were taken for a total of 127 points, at the depth of 0-5 and 25-30 cm during April (summer) and November (end of rainy season) of 1989. Soil analysis included electrical conductivity of soil saturation extract (Ece), and of soil solution at the soil water ratio of 1:5(EC1:5), the total concentration of soluble salts: [Na], [Ca] and [Mg] in the soil saturation extract, pH of soil to water solution of 1:1, and soil water content on mass basis (?m). Calculated variables were sum of soluble salt content ([Na+Ca+Mg]) and practical sodium adsorption ratio (SARp = [Na]/([Ca+Mg])0.5). Salt concentrations and EC values were higher in the upper layer of surface soil. This was more pronounced in summer. However, salt concentrations became higher in the rainy season, indicating increasing solubility and movement by water. Basic statistical analysis showed that only pH and ?m are normally distributed, with the arithmetic means of pH = 6.8 and ?m = 14.21%. All other variables are log-normally distributed, with the log-means of ECe = 4.08 dS/m, [Na] = 7.84, [Ca] = 14.92, [Mg] = 6.80 and [Na+Ca+Mg] = 27.99 mol/m3 and SARp = 2.01 mol0.5/m1.5. The average ECe was on the borderling of being saline soil. The log-means have smaller magnitude than the arithmetic means. Further analysis of the relationships between all nine variables showed that only 3 relationships are strongly correlated. These are the ralationships between ECe vs. EC1:5; ECe vs. soluble salt concentrations; and [Ca] vs. [Mg]. The correlation functions for the overall data (508 points) are as follows: i) ECe = 6.807EC1:5, (r = 0.956); ii) ECe = 0.8916 + 0.0731[Na] + 0.1702[Ca] + 0.0086(Mg), (r = 0.969) or [Na+Ca+Mg] =7.115ECe0.9571, (r = 0.957); and iii) [Mg] = 0.3295[Ca]1.024, (r = 0.882). Two other relationships have moderate r values. These are SARp = 0.9889 + 0.2716ECe, (r = 0.681); and pH = 6.27 + In([Na]0.123[Ca]0.368[Ng]-0.449), (r = 0.398). The rest have low values of r (r<0.4), even though some relationships are of statistical significance. The study leads to the conclusion that for the studied area, ECe can be evaluated from EC1:5; when EC1:5 is greater than 0.6 dS/m, the soil is saline. The dominant soluble salt is calcium. Calcium and magnesium behave similarly in their solubility. [Na] in the range of 3-5 mol/m3 is not related to [Ca] and [Mg], indicating a different solubility factor. At higher concentraiton, [Na] is positively related to [Mg]. When the total solube salt content is low, Na is more soluble and appears in higher concentration than Ca and Mg. When the soil has higher water content and/or is at lower pH, the three salts are in the more soluble forms, which are strongly and positively corredlated to each other. ECe of the soil is controlled predominately by the linear combination of [Na], [Ca] and [Mg]. Of the three salts, Ca has the most effect on ECe. Because ECe is related to the sum of salt concentrations, the expression of salts in the form of SARp is not as strongly related to ECe. Only the above 3 highly correlated relationships are recommended. |
|
ที่มา:Agricultural Science Journal (วารสารวิทยาศาสตร์เกษตร)หัวเรื่อง:ผลของค่าการนำไฟฟ้า และระดับ pH ของสารละลายธาตุอาหาร ต่อการเจริญเติบโต และการใช้ธาตุอาหารของผักกาดหอมคอส |
|
|
|
|
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Comparison Between Ohmic and Conventional Heating of Pineapple and Longan in Sucrose Solution) ผู้เขียน:ฐิตาภรณ์ ตัมพานุวัตร, ดร.วีรเชษฐ์ จิตตาณิชย์, รองศาสตราจารย์ , Supaporn Kaewchutong, Orapin Jan-Ob, Hoang Pham, ดร.ธนะบูลย์ สัจจาอนันตกุล, ผู้ช่วยศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractOhmic heating is an innovative thermal processing method in which an alternating electric current is directly released through food materials to generate heat. The temperature inside the food during ohmic heating can be raised rapidly and uniformly depending on the electrical conductivity of the food. In this research, the electrical conductivities of pineapple, longan and sucrose solution were measured. Furthermore, mixtures of fruit and sucrose solution at 12 ?Brix were heated from 30 ?C to about 90 ?C by ohmic and conventional methods. The aims were to: 1) investigate the possibility of applying ohmic heating to the mixture of fruit and sucrose solution; and 2) to compare the quality of ohmically heated samples with that of conventionally heated counterparts using the same heating rate. The results indicated that the electrical conductivities of pineapple and longan were in the ranges 0.1–1.3 and 0.3–1.0 S.m-1, respectively. Moreover, it appeared from the analysis of variance that there was no significant difference in the textural attributes between ohmically and conventionally heated samples whereas the color values were significantly different. In addition, a positive effect of ohmic heating on microbial reduction was found for the pineapple pieces with the numbers of mesophilic bacteria, molds and yeast in the ohmically treated samples being significantly lower than those of conventionally heated specimens. The energy consumption was comparable between the two techniques. The findings in this work confirmed that the ohmic method could be an interesting option for heating these products. |