จำนวน Repository ( 375 )

การทำงานเป็นทีมที่ส่งผลต่อประสิทธิภาพการทำงานของคุณครูและบุคลากรทางการศึกษาในสังกัด โรงเรียนสำนักงานเขตพื้น ที่การศึกษาประถมศึกษากรุงเทพมหานคร
การทำงานเป็นทีมที่ส่งผลต่อประสิทธิภาพการทำงานของคุณครูและบุคลากรทางการศึกษาในสังกัด โรงเรียนสำนักงานเขตพื้น ที่การศึกษาประถมศึกษากรุงเทพมหานคร

This independent study to the teamwork performance that affects the efficiency of government teachers and education personnel affiliated with the schools under the office of the primary education in Bangkok area. The objectives are 1) to study personal factors of education personnel that affect teamwork performance that affect the efficiency of government teachers and education personnel affiliated with schools under the office of the primary education in Bangkok area. Furthermore 2) to study the team composition that affects the work performance of teachers and education personnel affiliated to schools under the office of the primary education in Bangkok area. By using questionnaires designed to teachers and education personnel from the office of the primary education in Bangkok area for 334 samplings using the Taro Yamanae formula. Testing was done in descriptive statistics using frequency percentage mean and standard deviation while hypothesis testing was t-test F-test (ANOVA) and double test by method Least Significant Difference (LSD) and Pearson Product Moment Correlation Coefficient. The result of the study found that most responders were female aged between 21-30 years old working in middle-sized schools and having a bachelors degree. Most had an income between 15001-20000 Baht and most of them had been government teachers in operating positions for 5-10 years as civil servant and the study found team composition factors such as environment composition and appearance the feature design and process affected the teams performance at a high level. The reason was trust between education personnel team members. There also was a high degree of satisfaction with the working environment and the excellent collaboration between team members. Team members were able to resolve obstacles together effectively. There was good communication between members and the members had no conflict with each other’s. However the education personnel should have a positive attitude to work with other people and alone. Negative thinking cause no bias towards others and decrease performance. The results of the hypothesis testing indicated that sex age school size income position level different occupations of government teachers and education personnel could not differently affect teamwork performance as could not different for education job titles and working ages the difference will affect performance of the team composition factors. The factors were statistically significant at the 0.05 level and the team composition factor. There also was a correlation in the same direction with the efficiency of teamwork of government teachers and education personnel. It was statistically significant at the 0.05 level.

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การศึกษาสมบัติทางกลของโพลิเอทิลีนน้ำหนักโมเลกุลสูงยิ่งยวดเชิงประกอบสำหรับล้อ Run-flat
การศึกษาสมบัติทางกลของโพลิเอทิลีนน้ำหนักโมเลกุลสูงยิ่งยวดเชิงประกอบสำหรับล้อ Run-flat

This research project aimed to test the mechanical properties and the capability in wear resistance of ultra-high molecular weight polyethylene composite as well as determine the optimal formulation of UHMWPE-based composites which had a main component of aluminum oxide. The developed formula was used in the manufacture of run-flat wheels and thus applied to build run-flat wheels with an understanding of the proper molding conditions under the run-flat wheel forming process. Two materials used in the research consisted of super-high molecular weight polyethylene (UHMWPE) as the base material and the additive of aluminum oxide (Al2O3). The parameters employed in the hot compression process to obtain the specimen for the experiment consisted of compressive force temperature time and the ratio between super-high molecular weight polyethylene and aluminum oxide. The test for mechanical properties consisted of an impact test a hardness test according to the ASTM D2240 standard a tensile test according to the ASTM D638 standard type I and a wear test according to the ASTM G77 standard. The results indicated that a hot compression condition under a pressure of 5 MPa a temperature of 210°C for 90 min and using 5% Al2O3 HTM 30 material caused mixed uneven powder particle sizes between 2 to 5 µm. The tensile test results inferred the yield strength of 20.52 MPa ultimate tensile strength at 29.96 MPa breaking strength at 22.83 MPa elongation at break at 265.8% and modulus of elasticity at 784.46 MPa. The highest hardness was 62 shore D the high impact strength was 586.8 J/m and it was displayed for the wear rate of hot compression specimens made of UHMWPE mixed with 5% HTM-30. Moreover it introduced a coefficient of friction the wear rate and the density of 0.12 8.66E-11 mm3/N.m and 1.2446958 g/cm3 respectively.

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การศึกษาพารามิเตอร์ในการขึ้นรูปแผ่นเกราะเซรามิกส์รูปร่างหกเหลี่ยมกันกระสุน
การศึกษาพารามิเตอร์ในการขึ้นรูปแผ่นเกราะเซรามิกส์รูปร่างหกเหลี่ยมกันกระสุน

This research had two objectives that were to study parameters for forming bulletproof ceramic armor plates and to create a model of a bulletproof ceramic armor plate for small armored regular trucks. The parameters used to form a ceramic armor plate contain the thickness of the armor plate and the compressive strength which affects the density distribution of the green compact. A ballistic ceramic armor plate with a hexagonal shaped material was created as a concave bulletproof plate. Extrusion results displayed that the hexagonal material was formed at a very high density on the side surface of the armor plate but with uneven capacity distributed across the overall plate due to the friction occurring on the wall of the mold. The finite element method particularly at the Ansys/Explicit Dynamic tools were applied to analyse the damage of bulletproof plates. The model of a concave-shaped bulletproof plate was set for the SKD11material influencing the changes in the direction of the bullet firing when the bullet hit the bulletproof plate at a velocity of 880 m/s in accordance with the NIJ 4 standard. The bullet was made of tungsten carbide and the ceramic armor plate was built with a size of 300×300 mm and thicknesses of 14 16 18 and 20 mm. The bullet was fired into the center part and onto the curved surface of the ceramic plate. The result shows that the armor plate could not resistant to penetration. In this situation the direction of the bullets movement against the armor plate especially at a curved surface as a slope could result the deflection of the bullet direction as well as reduction of penetration capability.

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การศึกษาผลของกระแสฮาร์มอนิกส์ต่อค่าสูญเสียของหม้อแปลงไฟฟ้าเลื่อนเฟสและการทำให้เป็นจริงด้วยหม้อแปลงไฟฟ้าเลื่อนเฟส 15 องศา
การศึกษาผลของกระแสฮาร์มอนิกส์ต่อค่าสูญเสียของหม้อแปลงไฟฟ้าเลื่อนเฟสและการทำให้เป็นจริงด้วยหม้อแปลงไฟฟ้าเลื่อนเฟส 15 องศา

The trend of energy savings has been widely interested and phase shift transformers (HMT) have been extensively used. This paper presents the investigation of the effect of harmonic currents on losses of the HMT. In this paper a 15-degree HMT with quad secondary winding is applied to find the relationship between harmonic currents and losses of the HMT. This relation can be met by testing the active power of primary and secondary sides while the HMT supplies for two and four non-linear loads at 25% 50% 75% and 100% rated currents respectively. The results reveal that harmonic currents affect winding eddy current losses significantly and the losses for loading the two secondaries 1 and 2 are the same as loading the two secondaries 1 and 3 while both %THDi are different. However for loading the secondaries 1 and 2 the %THDi is more than 15% so it is not met IEEE 519 Std. while the HMT is supplied with four loads the %THDi has met IEEE 519 Std. and the losses are less than 57% compared to one load. As a result of these if the HMT is applied to an adjustable speed drive system it is not only reduced the harmonics but also saved the energies.

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การศึกษาการบำบัดน้ำเสียจากการย้อมผ้าแบบเคลื่อนที่โดยใช้ถ่านกัมมันต์จากกะลามะพร้าว
การศึกษาการบำบัดน้ำเสียจากการย้อมผ้าแบบเคลื่อนที่โดยใช้ถ่านกัมมันต์จากกะลามะพร้าว

The dyeing industry both of business size and household size where the remaining water from the dyeing process is dumped into pipes and flows into natural water sources causing sewage problems. Therefore a column type wastewater treatment system has been developed by using a filtration system along with an adsorption system. The materials used to treat the wastewater from dyeing are gravel sand charcoal from wood and activated carbon from coconut shell. The study was conducted on the synthesis activated carbon from coconut shell using for color and molecules adsorption. The amount of activated carbon from coconut shell was varied at 200 400 600 and 800 g applying with filter media and other adsorption materials taking 1 hour to treat the wastewater from dyeing. The parameter using to measure water quality consisted of color value pH suspended solids conductivity turbidity value COD and TKN to indicate the water quality before and after treatment evaluating the efficiency of the wastewater treatment system. The best ratio that can treat the color is the formula containing 800 g of coconut shell activated carbon. It was able to treat the color equal to 5.94 SU or 99.43 percent compared to the wastewater before treatment.

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