จำนวน Repository ( 891 )
การพัฒนาโครงสร้างสองชั้นระหว่างคอมโพสิตไฮดรอกซีอะพาไทต์-อลูมินาและเซอร์โคเนียเพื่อประยุกต์ใช้ทางการแพทย์
In this work the objective is to develop the bilayer structure consisting of hydroxyapatite-alumina (HAp-Al2O3) layer and 3 mol% yttria tetragonal zirconia (TZ-3Y) layer using conventional technique consisting of the simple pressing together with pressureless sintering. In order to obtain the desired characteristics of bilayer structure layer thickness cosintering temperature and Al2O3 addition on successful fabrication of HAp-Al2O3/TZ-3Y bilayer structure are investigated. The results indicated that the HAp-10A/TZ-3Y bilayer structure was successfully fabricated by single-end die pressing the powders in hollow cylindrical graphite die under 60 MPa pressure and further wet-bag isostatically pressing in oil to 300 MPa pressure before sintering at 1200 ˚C for 1 h. It is found that an addition of 10 vol% Al2O3 into the HAp outerlayer is the essential condition to effectively suppress the differences in densification and coefficient of thermal expansion of the two layers during cosintering at 1200 oC for 1 h. The obtained HAp-10A/TZ-3Y bilayered disc has diameter of 21.0 mm HAp-10A outerlayer of 4.5 mm thick and TZ-3Y underlayer of 2.5 mm thick. The XRD pattern of the powders crushed from its HAp-10A outerlayer revealed no transformation into other new phases demonstrating that there is no reaction between HAp and Al2O3 during sintering at 1200˚C. The cross-section morphology of HAp-10A/TZ-3Y bilayered composite obtained from the SEM result revealed the porous structure with good interconnectivity. The high porous structure of the bilayered composite provided high surface area for cell attachment indicative of good cell growth and differentiation. The primary grain sizes of HAp-10A outerlayer and TZ-3Y underlayer were in the range of 1-3 um and 100-500 nm respectively. The hardness of HAp-10A layer and /TZ-3Y layer in bilayer structure varied with different layer thicknesses. Accordingly the results presented in this work demonstrated that the HAp-10A/TZ–3Y bilayered composite fabricated by simple technique has thick HAp-Al2O3 outerlayer and strong interfacial bonding between interface layers which can be tailored for specific applications
การพัฒนาปรับปรุงการสร้างทองระดับนาโนด้วยการใช้จุลินทรีย์ท้องถิ่น ในประเทศไทย
The study is the development of biological methods for extracting gold from the effluents of the gold processing and gold extraction in the industries where has a very high acidity (pH 0-4). This method should be used to replace the electrochemical process and chemical method which cause the pollution of toxic substances acid fumes and heavy metals of copper cyanide to the environments. The research started at the characterization and identification of microorganisms presented in gold contaminated water in natural source where is highly acidic (pH 2-4) and it could synthesize nanogold particles. The bacteria Bacillus sp. E201 were identified from this source and it showed its 16S rDNA gene with similarity of 95% to bacteria Bacillus thuringiensis accession no. FJ755916. It could create gold in the solution outside the cells within three days Form 1 mM HAuCl4 • 3H2O solution the bacterial dry weight could yield 75.3% with the amount of 0.5115 grams. It could be able to withstand acidic conditions and harvest gold from the gold extraction solution after centrifugation and filtration. So this developed biological method could be developed to apply in the industrial production of gold and jewelry industry.
การพัฒนาเครื่องคัดแยกสิ่งเจือปนในเมล็ดข้าวปลูก
Thailand is an agricultural country. Most of the population consists of farmer. The rice is suitable to the climate of the country. And the main export of Thai is rice. The preparation of grain is also important.The farmer have to has an experience to choose the grain for growing the rice in farm. Good grian will give the high product. And good grain should completely free from contamination of disease and insect. Then it will be healthy seedlings. It is easy to harvest crops in a very high quality. Even it has good and high quality but it still has in impurities in the seed. Then the idea to create a project of sorting impurities from seeds. From the first it was built to help farmers to separate impurities such as grasses and husks. But the problem is the size of the maching is 140 x 150 x 160 cm which is larg and heavy then it makes the inconvenient to move. The preparation of the project is to develop an interest in sorting impurities in grain. The objective is to reduce the size to a smaller size than before. And increase the work more efficiency. The main aim is to sorting impurities in grain. Preparing the rice and put into the machin when power is opened. Rice will be flowing through the sieve which it works as a distribution and contamination. Then it will fail down into the sorting room. Impurities will be removed and the wind from the fan will blow the seeds. So we will get the good product and high quality. The results of the test. Wind is the best performance of the machine. Separating rice grains is 5.4 meters per second. The test of separating of the rice grains in 5 times and in the test of the 10 20 30 40 and 50 kg with a mixture of 10 percent of husk. the most effective of sorting rice is 10 kg. It can be isolated 99.30 percent with in 1.23 minutes.
การศึกษาและพัฒนากระถางพลาสติก
One of important equipment in reforestation or tree planting is a pot for mulching tree saplings. Originally pots were made of clay but they were too strong. When the trees grow up the pots must be smashed in order to let the roots and the stems grow up. Plastic pots are a popular alternative to be potted tree saplings due to their longer usability flexibility keeping and easy cleaning. In addition they are light and easy to move or transport. Typical pots usually have holes at the bottom which make poor ventilation that caused the slow tree saplings growth. Pots with holes in the side let the air comfortably flow and the roots do not go to the bottom of the pot. When the pots are moved the tree sapling roots are not ragged this help reducing the mortality rate of tree saplings. To Construct and find out the efficiency of plastic pot injection molded with 7.7 cm. in size 8 cm. high 0.10 cm. thick and the weight of 20 grams in the specification form the work-piece can be injected. For Construction and finding out the efficiency of holes for putting the plastic pot injection molded with 41 cm. wide 51 cm.long0.20 cm. thick and the weight of 330 grams in the specification form every work piece can be injected. There are 18holes for putting the plastic pot and all 18 holes are in the same size. Asst. Prof. Prasong KanKaew
การวิจัยและพัฒนาผลของอุณหภูมิต่ำที่เกี่ยวข้องต่อการเร่งการแข็งตัวของยางซิลิโคนเหลวชนิด RTV (Room temperature vulcanization)
การวิจัยฉบับนี้ได้กล่าวถึงการลดระยะเวลาการทำแม่พิมพ์ยางซิลิโคนโดยเร่งความแข็งด้วยอุณหภูมิต่ำ เนื่องจากแม่พิมพ์ยางซิลิโคนใส สามารถเก็บรายละเอียดของชิ้นงานได้ดีและสามารถมองเห็นชิ้นงานด้านในได้แต่แม่พิมพ์ยางซิลิโคนใสใช้เวลาในการแข็งตัวนาน จึงได้ศึกษาและทำการทดลองนำเอาอุณหภูมิความเย็นเข้ามาช่วยในการเร่งการแข็งตัวของซิลิโคนใสโดกำหนดอุณหภูมิเป็น 3 อุณหภูมิ ประกอบด้วย 10 5 0 องศาเซลเซียล แต่อุณหภูมิแบ่งเป็น 3 ช่วงเวลา ประกอบด้วย 2 3 4 ชั่วโมง จึงทำการการทดลองขั้นต่อไป จากการทดลองโครงการลดระยะเวลาการทำแม่พิมพ์ยางซิลิโคนใสโดยเร่งความแข็งด้วยอุณหภูมิต่ำเพื่อหาอุณหภูมิและช่วงระยะเวลาที่เหมาะสมในการเร่งความแข็งของซิลิโคนใส พบว่าที่อุณหภูมิ 5 องศาเซลเซียล ช่วงระยะเวลา 3 ชั่วโมงมีค่าความแข็งใกล้เคียงกับมาตรฐานและมีความเหมาะสมที่สุด เนื่องจากผลการทดลองพบว่าอุณหภูมิและระยะเวลาที่เหมาะสมที่สุดนั้นสามารถลดระยะเวลาการแข็งตัวของซิลิโคนใสได้ 6 ชั่งโมงและมีประสิทธิภาพใกล้เคียงกับชิ้นงานมาตรฐาน