จำนวน Repository ( 3447 )

การปรับปรุงความเหนียวและความทนแรงกระแทกของพอลิแลกติกแอซิดโดยการใช้น้ำมันถั่วเหลืองที่ผ่านการดัดแปรและเส้นใยธรรมชาติ
การปรับปรุงความเหนียวและความทนแรงกระแทกของพอลิแลกติกแอซิดโดยการใช้น้ำมันถั่วเหลืองที่ผ่านการดัดแปรและเส้นใยธรรมชาติ

This research work was to study the improvement of toughness and impact resistance of polylactic acid (PLA) with modified soybean oil (MSBO) and palm fiber (PF). The detail of this work was divided into three parts. The first was to find the suitable condition for modification of soybean oil with ozonolysis. The second and last parts were to study the effects of MSBO and PF contents on the properties of PLA respectively. For oil modification the reaction times were varied from 0 to 3 hours and the chemical changes in molecules of soybean oil were investigated by Nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopies. The result suggested that the most suitable condition for ozonolysis reaction was 2 hours considering the decrease in double bond between carbon atoms and the increase in hydroxyl group into molecular structure of MSBO. For the effect of MSBO content on mechanical properties it was evaluated by tensile and impact testing. Differential scanning calorimeter (DSC) and scanning electron microscope (SEM) were used for thermal and morphology analyses. The result showed that elongation at break and impact strength of modified PLA by MSBO increased about 89 and 25 % compared to those of neat PLA respectively. MSBO act as the efficient plasticizer for PLA considering the conversion of fracture behavior from brittle to ductile good dispersions of MSBO droplets in PLA and the decrease of glass transition temperature (Tg) with addition of MSBO. The addition of PF improved the impact strength of modified PLA. Strong interfacial bonding between PLA and PF indicated MSBO being both coupling agent for PLA and natural fiber and plasticizer for PLA. For migration test it was found that contents of released heavy metal and migrated chemical from specimens of PLA and PLA/PF composite were under the criteria according to Notification of the Ministry of Public Health (No. 295) B.E. 2548.

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การเตรียมและศึกษาสมบัติทางโครงสร้างและแม่เหล็กของอนุภาคคอมโพสิตระดับนาโนเมตรของไฮดรอกซีอะพาไทต์และซิงก์เฟอไรท์ เพื่อประยุกต์ใช้ในการรักษามะเร็งในอนาคต
การเตรียมและศึกษาสมบัติทางโครงสร้างและแม่เหล็กของอนุภาคคอมโพสิตระดับนาโนเมตรของไฮดรอกซีอะพาไทต์และซิงก์เฟอไรท์ เพื่อประยุกต์ใช้ในการรักษามะเร็งในอนาคต

A promising composite of zinc ferrite (ZnFe2O4) and bioactive hydroxyapatite (Ca10(PO4)6(OH)2 ;HAp) has expected to potential for future bone reinforcing formation. In present study zinc ferrite and hydroxyapatite composite was prepared by solid state reaction route for easier control of structural and magnetic characteristics and with low cost. Hydroxyapatite powder was synthesized by precipitation method from chicken eggshell. Mixed powders with varying ZnFe2O4/HAp weight ratios from 2-10 wt% were milled together and uniaxially pressed and then sintered at 1200 oC for 3 hours. The XRD results showing no other phases of composite with only HAp and ZnFe2O4 phases were identified indicating high stability of HAp property. Phase fractions of ZnFe2O4 were found to increase from 10.8 to 18.73 wt% with increasing content of ZnFe2O4. FT-IR results of ZnFe2O4/HAp composite were only revealed vibration bands of standard HAp phase. This may due to the overlapping of the ZnFe2O4 vibrational bands with HAp bands. However their intense variations observed in HAp vibrational bands indicated the interaction between ZnFe2O4 and HAp. The surface morphology of these ZnFe2O4/HAp composite exhibited primary grain in nano scale with enhanced pore structure and Interconnectivity when ZnFe2O4 weight ratios increased; indicating high surface area for cell attachment and better good cell growth and differentiation. The higher saturation magnetization as well as higher super paramagnetic behavior could be easily altered by increasing ZnFe2O4 content in the composite.

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การศึกษาค่าความถูกต้องของการวัดความต้านทานด้วยดิจิทัลมัลติมิเตอร์
การศึกษาค่าความถูกต้องของการวัดความต้านทานด้วยดิจิทัลมัลติมิเตอร์

In general the measured resistance with a digital multimeter. Users tend to be measured and then displayed on the screen to the user regardless of the value that is accurate or not. The value displayed on screen digital multimeter may be incorrect. As a result from wires access point measurement and other factor that affect to the value of measurement. Thus the study of factors that affect the measurement to get the accurate and more precise and also can be used in the operations. According to international standard quality system requirements for ISO are clearly on the meter or the measuring device must be calibrated and in the certificate specifies the gain calibration and the uncertainty of measurement. Therefore it is necessary to evaluate the uncertainty of measurement to comply with the standard splash. This thesis presents a study of the effect to the measurement resistance in 0.01 ohm to 100 mega-ohm by direct measurement for 2wire & 4wire Loading effect Using different kinds of conductors Thermal EMF and the stability of the resistor. Include the statistical analysis was used to estimate the uncertainty. From this study can be applied to measure the resistance in a variety of accurately and precisely.

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กลยุทธ์การประชาสัมพันธ์ที่มีความสัมพันธ์ต่อการรับรู้ภาพลักษณ์ของมหาวิทยาลัยราชภัฏสวนสุนันทาของประชาชนในกรุงเทพมหานคร
กลยุทธ์การประชาสัมพันธ์ที่มีความสัมพันธ์ต่อการรับรู้ภาพลักษณ์ของมหาวิทยาลัยราชภัฏสวนสุนันทาของประชาชนในกรุงเทพมหานคร

The purposes of the research were 1) to study the demographic are relationship to image of Suan Sunandha Rajabhat University (SSRU) 2) to study the perceptions of public relations is related to corporate image of SSRU 3) to study the relationship of perceived public relations strategies with the SSRU’s image in all dimensions. This quantitative research collected 400 samples of people in Bangkok chosen through multi-level sampling. Data were collected using a. questionnaire and analyzed using percentage mean standard deviation and MANCOVA The results showed that: 1) Most respondents were female aging between 15 and 26 years old holding senior high school being student having average monthly income unless 5000 Baht and not relationship with SSRU staff 2) Gender differences do not result in the recognition of different image to a statistically significant degree (p< .05) while age education salary and relationship with SSRU staff result in the recognition of different image. 3) The samples are perceived image of the SSRU in total is moderate (xˉ = 3.30). Media above the line in category social media has the most image recognition while media below the line in category personal media has the most image recognition. 4) The relations of media above the line and media below the line were a positive correlation to a statistically significant degree (p< .05).

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การสื่อสารการตลาดเพื่อส่งเสริมการเข้าร่วมกิจกรรมปั่นเพื่อพ่อของประชาชนในกรุงเทพมหานคร
การสื่อสารการตลาดเพื่อส่งเสริมการเข้าร่วมกิจกรรมปั่นเพื่อพ่อของประชาชนในกรุงเทพมหานคร

The Purposes of this research were to study demographic characteristics and marketing communications toward Bike for Dad participation in Bangkok on December 11 2015 of 99999 people registered to join this cycling event in 11 area throughout Bangkok. This is a qualitative research so that questionnaire is applied to 400 people in 6 event area in Bangkok. The research revealed that most of the respondents were female whose age was 36-59 years old and marital status was single. They were employees of private companies that had income THB 10000 – 20000. In marketing communications the research found the public relations and event promotion appeared to have a positive impact on the participation of Bike for Dad in Bangkok. Finding also indicates that there are 5 significant results of people to participate in the event : constancy congruity cooperation constitution and cycling. In term of practical contributions this study provides a useful marketing communication idea for Bike for Dad in Bangkok called “5C’s Information”. In the light of the results state agency can utilize these findings for strategic planning of marketing communication in Bike for Dad or other relevant activities in the future.

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