จำนวน Repository ( 80 )
การการศึกษาพฤติกรรมค่าความจุความร้อนของวัสดุความเสียดทาน
Nowadays one of the automotive engineering is conductivity of brake pads playing a role in friction coefficient which means safety of customer. Thus thermal properties have been improved using composited materials. This project aims to study the heat capacity behavior of 3 different brake pads which are supported by the company Compact International (1994) Ltd. For experimental works temperature based on brake condition was simulated from 05 to 003°C at 5 MPa of pressure. By standard JIS D4413 testing condition of pressure was referred. The heat capacity values of brake pads are calculated under the temperature conditions. As a result of testing brake pad made of copper or high metal powders result in relatively low heat capacity. On the other hand brake pads containing fiber and a large amount of fillers result in an increased heat capacity and stability in various temperature conditions. The heat capacity varied according to the operating temperature. In addition the lubricant contained in the brake pads affects the higher heat capacity and stability at various temperatures.
การพัฒนาคุณภาพของภาพนูนต่ำที่ทำจากวัสดุธรรมชาติชนิดต่างๆ
Based on the research on creation of bas-relief molds for production of bas-reliefs made from boiled pineapple leafs conducted by Rachadasak Pengcum of which purpose was to help generate income for members of Pineapple Leaf Paper Community Enterprise Ban Pasang Wiwat Mueang District Chiang Rai Province it was found that the bas-reliefs need further improvements in terms of appearance and durability as well as the use of other natural raw materials to produce them. The researcher therefore has considered developing the previous research by applying other 3 valueless natural materials which include rice straw water hyacinth and banana stem skin to make bas-reliefs for different beautiful surfaces of the products. Also the quality of bas-reliefs has been comparatively investigated by surveying satisfactions of members of the Community Enterprise and visitors to the project towards the bas-reliefs made from rice straw water hyacinth and banana stem skin. The total period of questionnaire distribution was 3 months. There are 59 respondents administering the questionnaires most of whom (43 persons) are female which accounts for 72.88 per cent. The majority of the respondents (25 persons) obtained junior/senior secondary school diplomas or equivalent accounting for 42.37 per cent. 16 respondents or 27.12 percent are 60 years of age. As for satisfactions towards the bas-reliefs made from rice straw 89 times of “strongly agree” was selected whereas 126 times of “pretty much agree” 75 times of “fairly agree” and 5 times of “disagree” were marked by the respondents. Concerning the bas-reliefs made from water hyacinth 87 times of “strongly agree” was selected while 97 times of “pretty much agree” 110 times of “fairly agree” and 1 time of “disagree” were chosen. When asked about the bas-reliefs made from banana stem skin the respondents selected 77 times of “strongly agree” 99 times of “pretty much agree” 110 times of “fairly agree” and 8 times of “disagree”.
การปรับปรุงความเหนียวของพอลิแลกติกแอซิดด้วยวัสดุธรรมชาติที่ผ่านการดัดแปร
This research work was to study the toughening modification of polylactic acid by the mixing with epoxidized natural rubber (ENR) and the increase of effectiveness of mechanical properties with a compatibilizer. Enhancement of properties in polylactic acid was evaluated by tensile and impact testings Fourier-transform Infrared Spectroscopy (FTIR) technique Differential Scanning Calorimetry (DSC) technique and Scanning Electron Microscope (SEM). For the addition of ENR it was revealed that the increase of ENR contents improved elongation at break and impact strength but decreased tensile modulus and ultimate tensile strength. Glass transition temperature (Tg) percentage crystallinity and the melting point of polylactic acid tended to decrease with the addition of ENR. Chemical change was found that position of C=O peak in polymer blend was slightly shifted as compared to the spectrum of neat polylactic acid. The optimum formulation for toughening modification was ENR content of 30 wt%. Its impact strength was 1982.55 % of neat polylactic acid. For increasing effectiveness of mechanical properties with a compatibilizer it revealed that the addition of Joncryl ® ADR-4300 as compatibilizer improved both tensile and impact properties. The optimum loading of a compatibilizer for improving mechanical properties was 0.5 wt% of polylactic acid. The decreases of crystallinity and melting point of polylactic acid with adding Joncryl ® ADR-4300 might be because Joncryl ® ADR-4300 was also chain extender of polylactic acid and it might be obstructing crystallization. The presence of Joncryl ® ADR-4300 unaffected on Tg value and chemical change.
การศึกษาพฤติกรรมค่าการนำความร้อนแบบไม่เชิงเส้นของวัสดุความเสียดทาน
Nowadays one of the automotive engineering is conductivity of brake pads playing a role in friction coefficient which means safety of customer. Thus thermal properties have been improved using composited materials. This project aims to study the conductivity behavior of 3 different brake pads which are supported by the company Compact International (1994) Ltd. For experimental works temperature based on brake condition was simulated from 200 to 400°C and cooled down from 400 to 200°C at 1 5 and 8 MPa of pressure respectively. By standard JIS D4413 testing condition of pressure was referred. The non-linear of conductivity value are calculated from the temperature under steady state condition. As a result of testing there are several of parameters effecting on the non-linear conductivity value. The brake pad that is a mix of high-fiber affects the fluctuation of thermal conductivity. At the same time lubricant in the brake pad cause the stability of conductivity value in different temperature range at the same pressure. On the other hand the brake pad mixed hi-copper inspires the narrow range of conductivity value in different pressures at the same temperature. Moreover the conductivity value as a mention is inversely proportion with the coefficient of kinetic friction.
การศึกษาประสิทธิภาพทางแม่เหล็กจากวัสดุคอมโพสิต ที่ใช้ในอุตสาหกรรม
The magnetic properties of Ba2FeMoO6 (BFMO) BaCO3 (Barium carbonate 99.9%) Fe(NO3)3.9H2O (Iron(II) nitrate 99.0%) and Mo03 (Molybdenum trioxide 99.0%) have been characterized. A slurry was prepared by mixing the powders with deionized (DI) water at a ratio of 1:7.5: by solid state reaction method through compression. In the case of BFMO sintering at 800 °C for a 4 6 and 10 hours. exhibited the largest hysteresis loop at 50 K. In addition the values of Ms and Mr indicate ferromagnetic behaviour in BFMO ceramics sintered from 600 °C to 800 °C. Finally the value of magnetization was reduced by using a lower sintering temperature SEM analysis revealed the physical appearance of sintered BFMO ceramic and showed the morphology of the BFMO powder was. coarse with an average diameter of 2 microns