PALF As Alternative In Novelty Composite
Pineapple leaf fiber (PALF) which is rich in cellulose, abundantly available, relatively inexpensive, low density, nonabrasive nature, high filling level possible, low energy consumption, high specific properties, biodegradability and has the potential for polymer reinforcement. The utilization of pineapple leaf fiber (PALF) as reinforcements in thermoplastic form for developing low cost and lightweight composites Pineapple leaf fibre (PALF) is one of them that have also good potential as reinforcement in thermoplastic composite. The objective our research is to characterize PALF and to investigate the effect of fibre treatment on the mechanical properties of PALF reinforced polypropylene (PP) composite PALF was obtained from pineapple plantation after the harvesting. The we dry the PALF to remove the water. Next step is grind the PALF into small particle. Both PP and PALF were compounded using internal mixer machine prior to compression moulding via hot press machine to form a sheet. After forming the composite sheet, samples were prepared for tensile test (ASTM D638), flexural test (ASTM D790) and impact test (ASTM D256).
會逆轉的石頭－RattleBack 逆旋現象
具有長短兩軸的對稱性剛體，譬如半橢球，在施加適當質量配重後，給予其Z 軸方向的 初角速度，將會逐漸上下震盪、搖擺，而後改變原先的角速度方向，朝相反的方向逆轉回來。 此現象稱為「逆旋現象」，本研究分析關於配重、質心距離與表面摩擦係數等因素的影響，利 用光點投影方式判讀其軌跡，並建立數學模型以驗證物理原理。研究發現，動摩擦垂直長軸 的分力所造成的力矩，將會導致逆旋的發生，並且，對本研究的剛體模型而言，加以20g 配 重，與長軸夾45°距質心5.5cm 且動摩擦系數為0.1227 時，逆轉角度有最大值。當長短兩軸 的震盪頻率相近時，甚至會發生兩軸能量的耦合現象，而有不只一次的逆旋。 The phenomenon was found for rigid bodies with long and short symmetrical axes, such as half-ellipsoids. We add extra masses ( Δm ) to a stone of the shape of half-ellipsoid and then give it an initial angular velocity ( 0 ω ) to make it spin. While the stone spins, the two symmetric axes start oscillating up and down. Then, remarkably, the spin of the stone slows down while the amplitude of oscillation increases until the direction of angular velocity reverses. This process is called “Rattle Back Spin-Reversed Phenomenon.” Our study involves the effect of several parameters on the above phenomenon, such as the shape of the stone, the added mass, and the friction between the stone and the table surface. We try to build a physical model to explain the spin-reversed phenomenon which can be recorded by tracing the motion of the stone with optical means. According to our study, the shape of the stone and the distribution of the added mass played crucial roles. The torque generated by kinetic friction along the long axis also helps the spin to reverse. Furthermore, in our experiment, we record a maximum reverse angle with following settings: two sets of 10 grams of mass are symmetrically added to the flat side of half-ellipsoid, in the distance of 5.5 cm to the C.M. of stone and an included 45 degrees angle with a long axis. And the most surprising finding is that when the oscillation frequencies of two symmetric axes are close to each other, the spin of the stone can reverse twice.
ELECTRONIC STUDENT-TEACHER POLL ATTANDANCE SYSTEM
Our goal is to make roll call systems at schools technological. While Rolling Call system is getting technological capacities some useful outcomes occur as well like; To remove the cost for class books by abolishing the class books used for roll call To eliminate mistakes with the usage of class book .(The numbers written incorrectly) To save again a large amount of waste paper( The short messages will be send to the parents instead of mailing the letters to the their adresses once a week about their students' absance.) To improve communication among school and parents ,by this way to prevent various kinds of problems arising from absenteeism. To make teachers school boards more efficently and motivated besides their affairs will get easier as well. To save time of school managers(They have no Works like saving the absenteeisms into e-school network because everything including all the absenteeism info will be carried into the system automatically) To save time of each lesson the teachers will not loose time for the roll call ,so they will be able to devote their time to their students and training. -Technological polling mechanism will contribute to education, this contribution will make all the students and teachers happy because all the teachers carry concern whether their curriculum will be finished or not through this system recording all the rests of teachers because of illnesses and some national celebrations.
Prototype Educational resources for teaching basic pneumatic
The didactic prototype for the teaching of the pneumatic Basic is designed, so teachers can instruct knowledgement of pneumatics focused to identification, handling and application of its elements based on constructivist theory in which the student learns making, working on projects and in a collaborative way. This implies that his presentation should include the basic elements to be used in this study area, as well as allowing that the student can interact with it, still easy to use, and take them by the teacher into his area of education, which can be a classroom, room, Auditorium, workshop, lab, and even training courses to the industry, the only thing that requires is compressed air (2 to 4 bars). As well as, to create a secure environment for the user when this is manipulating. Its construction based on a compact, lightweight and ergonomic, structure to ensure that it can be transported without difficulty. Also that must comply with the minimum essential to enable the student to acquire competencies in the curriculum which consider the identification, handling and application of pneumatic elements; IE has the following 2 directional valves 3/2 NC, 1 directional valve 3/2 NC-operated with a knob, 2 valves 3/2 pneumatic drive, a 5/2 valve NC NC of stable pneumatic drive, 1 valve of simultaneity or function, and 1 valve selector or function, or double effect with pressure regulator piston1 piston of double effect, 1 piston for simple effect, 1 valve 3/2 NC with motorized drive and roller.
Recycled PET bottles for vacuum packaging
Vacuum packaging is a packaging technique intended to extend the shelf life of food via the removal of air from an enclosed package prior to sealing. This process limits the growth of aerobic bacteria or fungi due to oxygen deprivation. In this work, we present a novel do-it-yourself vacuum packaging device using the exchange of water and air between two bottles to continuously generate a vacuum-suction effect. The sizes of bottle and vacuum bag were investigated for its impact on the vacuum generation in a plastic bag containing smoked fish sausages. Large commercial 3.1-litre PET bottle generated more vacuum than the smaller ones. An equilibrated vacuum pressure of a smaller plastic bag was lower than that of a larger size. With 3.1-litre PET bottles, the vacuum pressure for 3”x5”, 5”x8” and 6”x9” bags was equilibrated at 8, 10, 18 mmHg, respectively. Sausages packaged by our device last for 14 days when they were kept in -20oC refrigerator, which was comparable to those packed by the commercial vacuum packaging system for household use. This project demonstrates an application of simple science in a real life situation as well as a promotion of environmental protection idea as the electricity is not used in the vacuum generation process and the disposed plastic bottles can be reused.