จำนวน Repository ( 3447 )

ความเป็นพิษร่วมของเอทิลีนไดเอมีนเตตระอะซิติกแอซิดและสารลดแรงตึงผิวสังเคราะห์ต่อแหนเป็ดใหญ่และแหนเป็ดเล็ก
ความเป็นพิษร่วมของเอทิลีนไดเอมีนเตตระอะซิติกแอซิดและสารลดแรงตึงผิวสังเคราะห์ต่อแหนเป็ดใหญ่และแหนเป็ดเล็ก

Using of ethylenediaminetetraacetic acid (EDTA) and synthetic surfactant increase the chemical contamination in water. The co-phytotoxicity of EDTA (0-20 mg/l) and 3 synthetic surfactants; Triton X-100 (0-10xCMC) Tween 80 (0-10xCMC) and sodium dodecyl sulfate (SDS) (0-2 x CMC) on the growth of 2 duckweeds spirodela polyrrhiza and Lemma perpusilla were studied for 3 days. The results showed that the surfactant were phytotoxic on the growth of both plants while EDTA was not. SDS was the most toxic to plant especially on all chlorophyll content. Triton X-100 was only toxic to the growth of L. perpusilla and weight of S. polyrrhiza. Tween 80 was less or the least toxic to both plants. This surfactant only decreased chlorophyll a and total chlorophyll content of S.polyrrhiza and L. perpusilla. There was not any interaction between EDTA and surfactant on most toxicity tests. With these results synthetic surfactant contamination should be more concerned than co-contamination with EDTA.

2563
การประเมินชั้นดินและค่ากำลังแรงแบกทานที่ยอมให้ด้วยการทดสอบการเจาะสำรวจแบบหยั่งเบา
การประเมินชั้นดินและค่ากำลังแรงแบกทานที่ยอมให้ด้วยการทดสอบการเจาะสำรวจแบบหยั่งเบา

This study applied the kunzelstab penetration Test (KPT) or Light Penetrometer to examined penetration resistance values geological profiles and estimate shear strength properties of soils. KPT tests were carried out on steep slopes that exhibit potential slope movement in Chiang Rai province. The principal uses of the KPT are examined; i.e. correction method for N’KPT’ soil profile and allowable bearing capacity of soil foundation. KPT tests were conducted at 13 boreholes each measuring 4.00 m long along the crown of the slope. The results indicated the compacted layer and located the firm layer of soil foundation. The average allowable bearing capacities were 1.53 t/m2 at depth of 1.00-5.00 m and 17.06 t/m2 for 5.00-6.00 m depth respectively. Furthermore this paper presents an analysis of the stability of a slope with the shear strength parameters of the soil and the geological profile were defined based on the results of KPT. The results of factor of safety were below the stable value for analysis cases with groundwater table. Test results demonstrate the usefulness of the KPT method in geotechnical investigations to estimate soil profile and bearing capacity efficiently and economically. This approach is also less time consuming compared to other geotechnical site investigation methods.

2563
การพัฒนาเครื่องอบแห้งข้าวเปลือกแบบไหลต่อเนื่องด้วยเทคนิคการแผ่รังสีความร้อนในแนวรัศมี
การพัฒนาเครื่องอบแห้งข้าวเปลือกแบบไหลต่อเนื่องด้วยเทคนิคการแผ่รังสีความร้อนในแนวรัศมี

The objective of this research was to design and development of a continuous flow paddy dryer with infrared radial radiation technique. The prototype of dryer consists of two concentric circular cylinders cylinders which the paddy drying chamber is height of 1 m. The inner cylinder has diameter of 26.5 cm made from glasses and outer cylinder has diameter of 29.5 cm made from perforated (1.75 mm) steel sheet. At the center of cylinders installed 1200 w of electric infrared heater. A hopper was installed on the top of the chamber while 120 w of blower and paddy flow control were installed at bottom of chamber. The performance of the dryer in terms of specific energy consumption (SED) drying rate (DR) and quality of paddy i.e. head rice yield (HRY) and whiteness index (WI) were evaluated by drying 15 kg of paddy with initial moisture content of 23-26% (w.b.) by using the drying conditions of 80oC of drying chamber temperature 1.075 m3/min of air flow rate and 0.837 1.228 1.875 and 2.308 kg/min of paddy flow rate. The results found that paddy flow rate at 1.875 kg/min is the optimum condition because gave the highest DR lowest SEC and rice qualities (HRY and WI) closely to control.

2563
ผลของสารทำให้เกิดเจลต่อลักษณะเนื้อสัมผัส การเกิดซินเนอริซิส และคุณลักษณะทางประสาทสัมผัสต่อผลิตภัณฑ์แยมมะม่วงมหาชนก
ผลของสารทำให้เกิดเจลต่อลักษณะเนื้อสัมผัส การเกิดซินเนอริซิส และคุณลักษณะทางประสาทสัมผัสต่อผลิตภัณฑ์แยมมะม่วงมหาชนก

At the present the studies on the Mahachanok jam product is limited. The objective of this research was to study in the textural syneresis and sensory characteristics of Mahachanok jam from three types of geldings (pectin galactomannan and carrageenan) and different storage conditions (room temperature 4o C) for 1 month. It was found that the gel strength rupture strength and brittleness of the Mahachanok jam from carrageenan and galactomannan were higher than pectin (p≤0.05). When the jam was stored at 4oC jam from pectin had highest brittleness and jam from galactomannan had syneresis more than carrageenan and pectin (p≤0.05) respectively. The jam was stored at 4o C found that the syneresis was lower than stored at room temperature. For sensory evaluation the overall acceptance of Mahachanok jam from pectin and carrageenan were higher than galactomannan with the mean of like score between slight to moderate.

2563
การศึกษาเชิงทดลองการเพิ่มประสิทธิภาพแผงเซลล์แสงอาทิตย์โดยใช้ท่อความร้อนแบบแบน
การศึกษาเชิงทดลองการเพิ่มประสิทธิภาพแผงเซลล์แสงอาทิตย์โดยใช้ท่อความร้อนแบบแบน

The purpose of this research was to improve the efficiency of solar cell modules by cooling with heat pipes. The test set consisted of three 80 watt solar modules that were made of mono-crystalline. The first module did not install heat pipes while the second module installed heat pipes using ethanol as the working fluid and the third module installed heat pipes using R-11 as working fluid. Solar radiation intensity electrical energy produced by the solar modules and temperature of the solar modules were recorded. The results showed that the average temperature of the first solar cell module was 52.9oC and the case of not install heat pipes on module. For the units with heat pipes it was found that unit with ethanol heat pipe had an average temperature of 50.7oC and efficiency at 10.2% whereas the unit using R-11 heat pipe had an average temperature at 49.2oC and efficiency at 11.8% From the experiments it was concluded that the installation of heat pipes could increase the efficiency of solar cell mokules.

2563