จำนวน Repository ( 1087 )

การหาปริมาณปรอทในตัวอย่างครีมหน้าขาวโดยเทคนิคการวิเคราะห์ปรอทโดยตรงด้วยการสลายตัวด้วยความร้อน
การหาปริมาณปรอทในตัวอย่างครีมหน้าขาวโดยเทคนิคการวิเคราะห์ปรอทโดยตรงด้วยการสลายตัวด้วยความร้อน

Direct thermal decomposition mercury analysis is an efficient technique for determination of mercury in facial whitening creams. The analysis can be performed without any sample preparation. The samples can be weighed and placed directly into the analyzer. Thus there is no chemical waste produced in sample preparation. The time and energy used in sample digestion are saved as well. The calibration curve between mercury absorbance in terms of peak height and weight of standard mercury in the range of 0.1-10 ng was created. The calibration curve was linear followed the equation y=2.003x10-2X– 5.14x10-4 with coefficient of determination (R2) 0.9991. The precision in term of repeatability were 14% and 5.9% rsd (n=3) at 1.2 and 868 µg kg-1 respectively. The recoveries were between 88-110%. The detection limit (LOD) was 0.1 µg kg-1 (3sd/m n=10). The amount of mercury detected in 12 whitening cream samples sold in Chonburi province during the year 2019 were within the safety standard permitted in general cosmetics under the notification of the Ministry of Public except two samples were over the permitted standard.

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การพัฒนาแบบจำลองและการพยากรณ์ดัชนีรังสีอัลตราไวโอเลตรายชั่วโมง โดยใช้โครงข่ายประสาทเทียมในจังหวัดสงขลา
การพัฒนาแบบจำลองและการพยากรณ์ดัชนีรังสีอัลตราไวโอเลตรายชั่วโมง โดยใช้โครงข่ายประสาทเทียมในจังหวัดสงขลา

In this work solar erythemal ultraviolet radiation (EUV) which affects human skin and skin cancer was investigated at Songkhla province (7.2°N 100.6°E). EUV was converted to UV index then the data was used for model development and forecasting of hourly UV index using Artificial Neural Network (ANN). The ANN model has one input layer two hidden layers and one output layer. This input layer consists of extraterrestrial erythemal ultraviolet radiation solar zenith angle aerosol optical depth and cloud index which affect ultraviolet radiation and the output layer is hourly UV index. The results show that hourly UV index obtained from ANN and that from the measurement are in reasonable agreement with root mean square difference of 12.8% and mean bias difference of -2.4%. For forecasting of the hourly UV index the data for 7 days earlier was used for forecasting the next UV index for one day or nine-hour (08:00 am.-16:00 pm.). Multi-layer perceptron and back propagation algorithm were used in the model forecasting. The results show that the UV index from the model forecasting is reasonable agrees with UV index from measurement with root mean square difference of 17.0% and mean bias difference of 0.3%.

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การวิเคราะห์โครงการผลิตหมึกพิมพ์รองพื้นสีขาวฐานตัวทำละลายสำหรับผลิตบรรจุภัณฑ์อ่อนตัว
การวิเคราะห์โครงการผลิตหมึกพิมพ์รองพื้นสีขาวฐานตัวทำละลายสำหรับผลิตบรรจุภัณฑ์อ่อนตัว

The research proposes to find an optimum ratio of solvent based white ink for flexible package development by studying and comparing the qualification of white ink on plastic film. The process consists of separating the white ink ratio into 5 sampling group ratios and then examining ink quality by its’ solid content and grinding. The viscosity is controlled in 16 second and then measured by Zahn’s cup no. 3. The sampling ink is printed and inspected printing quality by (1) E*ab and opacity on polyethylene terephthalate (PET) plastic film and oriented polypropylene (OPP) and (2) bond strength by extrusion. The result shows that sampling ink with hardener substances and ink and varnish ratio is at 90:10 certifies in all aspects compare with other sample. Indicators are the net present value (NPV) Benefit/Cost Ratio: B/C Ratio Pay Back Period and internal rate of return of investment (IRR). The Feasibility Study found that the projects are the net present value (NPV) of 5053593 baht payback period of 1 year 8 month and rate of return on investment (IRR) was 54.79 %. B/C ratio = 1.25

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การวิเคราะห์ปริมาณสารสำคัญและฤทธิ์ต้านอนุมูลอิสระของสารสกัดใบกะเปียดเครือ
การวิเคราะห์ปริมาณสารสำคัญและฤทธิ์ต้านอนุมูลอิสระของสารสกัดใบกะเปียดเครือ

Premna trichostoma Miq. (Lamiaceae) mainly distribute in Asia including Thailand. Folk healers use this plant to treat fever as a juice splash and bathe. The aims of this study are to evaluate the quantity of active constituents and antioxidant activity of P. trichostoma leaf extract. Total phenolic compounds were determined using Folin-Ciocalteu method. Total flavonoid contents were determined by Aluminum chloride method. The amount of apigenin and kaempferol contents were analyzed by high performance liquid chromatography (HPLC). In addition the antioxidant activity was evaluated by DPPH and ABTS assay. The results showed that total phenolic contents total flavonoid contents and the amount of apigenin and kaempferol of P. trichostoma leaf extract was 46.45±15.30 mg GAE/g extract 25.48±2.02 mg CE/g extract 11.16±0.04 and 4.54±0.08 µg/g extract respectively. The IC50 values from the DPPH and ABTS assay was 117.50±1.22 and 36.14±1.53 µg/ml respectively. This study shows the antioxidant properties and active constituents of P. trichostoma leaf extract which indicates the potentials for further development of this plant

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ฤทธิ์ต้านแบคทีเรียของผ้าย้อมคราม
ฤทธิ์ต้านแบคทีเรียของผ้าย้อมคราม

The objective of this research was to study the antibacterial activity of 16 samples of indigo dyed fabrics that are produced and sold in Sakon Nakhon Province. Effect of moisture and pH of indigo dyed fabrics on bacterial growth were also determined. The result of the study shows inhibition of S. aureus TISTR 746 and E. coli TISTR 073 by agar diffusion plate test all samples could inhibit Saureus TISTR 746 (accounted as 100%) and only 9 samples could inhibit E. coli TISTR 073 (accounted as 56.25%). Whereas the study of antibacterial activity by AATCC test method 100-2004 at 24 hours was found that the natural indigo dyed fabrics code A3-1 could inhibit both bacterial strains in the highest level. The result also shows the effect of moisture and pH of indigo dyed fabrics on bacterial growth it was found that the increased humidity levels of indigo dyed fabrics have effect on the reduction of the inhibition efficacy of both strains. While indigo dyed fabric with pH 3.0 was found to inhibit most of the growth of both strains. In addition images obtained using a scanning electron microscope (SEM) could clearly confirm the property of indigo dyed fabric on inhibition of S. Aureus TISTR 746 and E. coli TISTR 073.

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