จำนวน Repository ( 816 )
การใช้ยางธรรมชาติผสมขุยมะพร้าวสำหรับขึ้นรูปแผ่นผนังป้องกันเสียงและความร้อนภายในอาคาร
This research aims to develop the coconut coir and fiber indoor acoustic and thermal insulation boards mixed with natural latex. The 5 ratios of coconut coir: coconut fiber: natural rubber were equal to 0.1: 0.9: 0.1 0.1: 0.9: 0.15 0.1: 0.9: 0.2 0.1: 0.9: 0.25 and 0.1: 0.9: 0.3 by weight. The indoor acoustic and thermal insulation boards were produced by knitting the coconut coir and fiber spraying the natural latex and heat compressing. The properties testing of indoor acoustic and thermal insulation boards included the density test water absorption test tensile strength test thermal conductivity test sound protection efficiency test and real usage test. From the results 0.1: 0.9: 0.15 ratio is the most suitable ratio of coconut coir and fiber indoor acoustic and thermal insulation board mixed with natural latex. The natural latex which putted in these indoor acoustic and thermal insulation boards can reduce the water absorption and increase tensile strength and sound protection efficiency.
ผลิตภัณฑ์แผ่นฝ้าเพดานผสมขุยมะพร้าวที่มีสมบัติต้านทานการดูดซึมน้ำและเป็นฉนวนป้องกันความร้อนสำหรับชุมชนท้องถิ่น
This research aims to develop the coconut coir ceiling board mixed with natural latex. The 6 ratios of gypsum plaster: coconut coir: sodium silicate: natural rubber: tap water are equal to 1: 0.15: 0.03: 0.00: 1 1: 0.15: 0.03: 0.01: 1 1: 0.15: 0.03: 0.02: 1 1: 0.15: 0.03: 0.03: 1 1: 0.15: 0.03: 0.04: 1 and 1: 0.15: 0.03: 0.05: 1 by weight. The ceiling boards were produced by casting in normal temperature (30 – 35 degree of Celsius). The properties testing of coconut coir ceiling board mixed with natural latex followed the TIS 219-2009 standard (gypsum plasterboard) including: breaking load nail pull resistance deflection water absorption density thermal conductivity coefficient and real usage. From the results 1: 0.15: 0.03: 0.03: 1 ratio is the most suitable ratio of coconut coir ceiling board mixed with natural latex. This developed ceiling boards can reduce the quantity of coconut coir waste and get the good thermal insulation ceiling board products.
Energy saving strategies in refrigeration systems by defrost management
Defrosting at evaporator panel is one of working cycles in freezer. Power consumption in defrosting does not meet the objective of using freezer therefore the approach to decrease power consumption in defrosting is one strategy for energy saving. Normally the cycle of defrosting in freezer is a constant time that specify by referring to the highest humidity period. With this control concept the problem of temperature exchange is not occurred from ice accumulation at evaporator panel but it makes the over necessity of defrosting process in the low humidity season and cause the unnecessary power usage in freezer. This research presents the control approach for defrosting by using the difference of the temperature at evaporator and the temperature at chilling area. By using this approach the defrosting process is operated depend on load and the fan is on or off relate to defrosting time. Test results demonstrate that about 12% of power can be saved by this control approach when compared to constant time control.
ผลกระทบจากเอ็นบีทีไอต่อสมรรถนะของวงจรรวมดิจิทัลที่สร้างด้วยเทคโนโลยีฟินเฟต
In FinFET-based VLSI designs heat issues from increase of driving current with temperature and self-heating effect profoundly influence the circuit performance and reliability. This work evaluates the performance of FinFET-based combinational circuits considering BTI stress and thermal effect of supply voltage and frequency variations. The proposed simulation framework is applied to selected benchmark circuits implemented with the 14-nm tri-gate bulk FinFET technology. The experimental results reveal that as temperature increases BTI aging delay increasingly worsens yet it is overridden by performance gain from the increase in driving current. We also prove that BTI degradation is dependent on power supply and frequency through their thermal impacts. Further we introduce a DVFS based power reduction approach that scales down the supply voltage of hot circuits to maintain the performance. The results show that power reduction yielded from the proposed technique is larger for all circuits working at higher ambient temperature (as large as 66% in some experimental circuits working at 20 oC above the baseline ambient temperature) with a slight decrease in BTI degradation.
การควบคุมกำลังไฟฟ้ารีแอคทีฟเพื่อเพิ่มมูลค่าทางเศรษฐศาสตร์ ในระบบไฟฟ้ากำลัง
To Improvement the power factor is very important. Because the costs are increased or reduced. To Improvement the power factor the higher the value it is necessary to buildings offices and industrial buildings or the fact that the industry needs real power. And reactive power source to operate. This research presents the design and construction of reactive power factor control. Which amounted to 6 working order by the first sequence is divided into three three-phase electrical power system and three consecutive singles phase by active power different. first1 is reactive at 5 kVAr second 2 and third 3 are reactive at 2.5 kVAr forth 4 fifth 5 and sixth 6 precious marine active 0.83 kVAr control. the power factor controller that controls RG3-12 pay Oval active in various sequences. As a result when not equipped with reactive power compensation software to control the power factor. This makes the flow of the high and low Power Factor schedule. When equipped compensate reactive power source to power factor control. Single-phase motor 1 kW and light bulb 1640-watt making the current decline of 14 amps rest 12 amps of the power factor increases from 0.5 to 0.929. When connected to three-phase motor with 2 kW 0.8 2.2 flow down from 2.360 rests 0.942 amps of power factor value up from 0.308 to 1.0.