Experimental Study on Optimization of Filler Concentration of Silicon Rubber Compound Used in High Voltage Insulators

In any power transmission system, insulators are essential for a reliable electrical power supply. The Efficiency of insulators will be decided by their electrical and mechanical properties. Recently in many of the power transmission systems, the conventional porcelain insulators are being replaced by polymeric insulators due to various advantages in their properties. Polymeric insulators have been increasingly popular in recent years as a result of their superior performance in contaminated environments due to their hydrophobic nature. However, research is still being carried out on Polymeric material with regards to ageing condition and feasibility for large scale utilization. Ageing of insulation is due to Environmental, Tracking and Erosion conditions. Ageing leads to immature failures and uncertainty in the performance of the insulators. The constituent materials and their properties have a significant impact on the performance of polymeric insulators. There is a strong need to look into newer filler materials which can be added to the existing polymeric base materials to constitute a composite. Keeping this in mind, in the proposed research uses Silicone rubber as base polymeric material and along with that additives are added to arrive at three different composites. A new filler material will be added to the base material forming a new composite. All these HTV Silicone rubber based composites are then tested the recovery of hydrophobicity, dielectric strength, hardness, specific gravity, tensile strength , ultimate elongation ,tear strength properties based on ASTM standards. Further, Inclined plane Tracking and Erosion studies are also conducted on the polymeric test samples for 6 hours to evaluate the SiR housing material suitability for outdoor insulator applications by subjecting them to AC high voltages under laboratory conditions as per IEC 60587 standards. Keywords: Recovery of hydrophobicity, dielectric strength, hardness, specific gravity, tensile strength, ultimate elongation, tear strength, inclined plane tracking and erosion, ageing, filler material.

Ergonomic aspects of material separation process modeling on stationary screw surfaces

The motion of material particles on gravitational surfaces, ie the motion of particles on surfaces under the action of its own weight, is used in special devices for their separation by physical and mechanical properties. For this purpose stationary screw surfaces of a steady step are applied. A number of papers have now considered the relationship between the kinematic parameters of motion, the coefficient of friction and the design parameters of the separator, when its surface is a deployable helicoid. The purpose of the study is to investigate helical surfaces with different design parameters in order to improve their separation ability through mathematical and geometric modeling of the process without making surface models. The problem of finding the trajectory of a material particle on the surface under the action of its own weight is preceded by the problem of finding the trajectory on an inclined plane. If a material particle with a certain initial velocity vо and a certain angle of inclination to the horizon falls on an inclined plane, it will move along a certain curve (in the absence of friction and air resistance, the trajectory will be a parabola). A system of equations is obtained, which describes the motion of a material point on the gravitational surface in the general case. If it is created for a specific surface, nonlinear and numerical methods must be used to integrate it. Modern software products allow not only to find the trajectory of the particle, but also to show it on the surface and even make an animation that essentially replaces high-speed shooting. This approach makes it possible to study the kinematic parameters of motion on different helical surfaces without full-scale samples of these surfaces, which significantly reduces the cost of finding the right surfaces. The motion of particles along a helical conoid and a deployable helicoid is considered. Simulation of the motion of a material particle on helical surfaces and its study by modern means of numerical integration and visualization have shown that for different surfaces the nature of the motion of the particle will also be different. When moving on the surface of the helical conoid, the particle in the presence of friction first accelerates, and then stops at a considerable distance from its axis. To prevent this, you need to take a limited compartment of the conoid both in height and on its periphery. When a particle moves on the surface of a deployed helicoid, its velocity becomes constant over time, and the trajectory after that will be a helical line. Key words: particle motion, helical surfaces, helical conoid, deployable helicoid, simulation

Movement of the particle on the surface of the conveyor belt, arbitrarily oriented in space

The movement of the material on the inclined belt of the conveyor takes place during transportation or its frictional cleaning. For an inclined moving plane (slide), the angle of its inclination to the horizontal plane is decisive. The absolute motion of a particle is the sum of two motions - the portable belt and the relative particle along the belt, so it is affected by the angle between the vectors of the greatest inclination of the plane and the transfer velocity of the plane (tape). The purpose of the study is to determine the motion of a material particle on the conveyor belt for the case when the angle between the vector of the line of greatest inclination of the conveyor plane and the direction of its transfer speed is arbitrary. To do this, the conveyor belt element was depicted as a rectangle with an axis of symmetry drawn along the direction of translational movement. In the initial position, the plane was placed horizontally, so the angle of greatest inclination is absent. In the future, the plane was given an arbitrary location in space due to alternate rotation around the sides bounding its compartment or around the axes of symmetry of the compartment, which is equivalent. The relative and absolute motions of the material particle along the moving web of the conveyor are considered for the case when the line of the greatest inclination of the web plane makes an arbitrary angle with the direction of the portable motion of the web. A system of differential equations of motion is compiled and solved. The obtained results are illustrated graphically. It is established that the nature of the relative motion of a particle on an inclined plane moving rectilinearly and uniformly depends on the direction of the vector of the line of the greatest inclination and the value of the angle of inclination of this plane. If the angle of inclination is less than the angle of friction, then the lateral feed of the particle will eventually stop either on the curved section of the trajectory or on a straight line that is parallel to the line of greatest inclination. The stopping place of the particle depends on the value of the initial velocity. At an angle of inclination of the plane equal to the angle of friction, the particle during the movement along the curved section of the trajectory reduces its initial velocity by half and then moves in a straight line and evenly. If the angle of inclination of the plane is greater than the angle of friction, the particle in relative motion along the curvilinear section of the trajectory first reduces the velocity, and when approaching a rectilinear section, its velocity increases and continues to increase on a rectilinear section of the trajectory. Key words: material particle, conveyor, inclined plane, plane inclination angle, particle velocity

PENGEMBANGAN PETUNJUK PRAKTIKUM GAYA GESEK DI BIDANG MIRING BERBASIS VIDEO TRACKING UNTUK MENINGKATKAN MINAT MAHASISWA

ABSTRAKPenelitian ini bertujuan menghasilkan petunjuk praktikum berbasis video tracking yang valid, praktis, dan efektif, serta mampu meningkatkan minat mahasiswa pada materi gaya gesek di bidang miring. Metode yang digunakan adalah Research and Development (R&D) dengan mengacu pada model pengembangan 4D (Define, Design, Develop dan Disseminate). Secara umum petunjuk praktikum yang dikembangkan meliputi dua topik kegiatan yakni penentuan koefisien gesek statis dengan memanipulasi kemiringan bidang serta koefisien gesek kinetis dengan menganalisis gerak benda di bidang miring. Petunjuk praktikum dalam rancangan menggunakan model praktikum/percobaan tertutup. Hasil validasi ahli yang mencakup aspek kelayakan isi, penyajian, komponen kebahasaan, dan keterlaksanaan menunjukkan petunjuk praktikum hasil pengembangan dinilai valid dengan perolehan skor rata-rata 4,03 dan layak digunakan. Hasil uji kepraktisan yang terdiri dari komponen kemenarikan, kemudahan penggunaan, dan manfaat petunjuk praktikum yang dikembangkan juga dinilai praktis dengan perolehan nilai rata-rata 3,93. Hasil uji efektifitas terhadap petunjuk praktikum menunjukkan bahwa produk pengembangan ini dinilai efektif untuk meningkatkan minat mahasiswa (kategori tinggi). Dengan demikian dapat disimpulkan bahwa produk petunjuk praktikum berbasis video tracking ini valid, praktis, efektif untuk digunakan sebagai penuntun praktikum serta mampu meningkatkan minat mahasiswa. Kata kunci: Petunjuk praktikum; video tracking; minat mahasiswa. ABSTRACTThis study is conducted to produce practical video tracking-based instructions that are valid, effective, and can increase student interest in the frictional force material on an inclined plane. The method used in this study was Research and Development (R&D) concerning the 4D development model (Define, Design, Develop and Disseminate). In general, the developed practicum instructions had covered two topics of activity, namely the determination of the coefficient of static friction by manipulating the slope of the plane and the coefficient of kinetic friction by analyzing the motion of objects on an inclined plane. Practical instructions in the design adopted a closed practicum/experimental model. The results of expert validation which include aspects of the feasibility of content, presentation, linguistic components, and implementation indicated that the practicum instructions developed were estimated valid with an average score of 4.03 and were suitable for use. On the other hand, the results of the practicality test consisting of components of attractiveness, ease of use, and the benefits of the developed practicum instructions were also considered practical with an average score of 3.93. Moreover, the results of the effectiveness test on the practicum instructions showed that this development product was considered effective for increasing student interest (high category). Thus, it can be concluded that this video tracking-based practicum guide product is valid, practical, effective to be used as a practicum guide, and is able to increase student interest. Keywords: Practical Instructions; video tracking; student interest.

Utilization of the phyphox application (physical phone experiment) to calculate the moment of inertia of hollow cylinders

Experiments have been carried out on determining the value of the moment of inertia of a hollow cylinder. This study aims to analyze the value of the moment of inertia with variations in the radius of the hollow cylinder using the Phyphox Application (Physical Phone Experiment). This research is experimental. The tools and material used area 1-meter longboard, three hollow cylinders with different radius sizes but the same mass, smartphone, laptop, caliper, and balance.The experiment of rolling motion on a hollow cylinder on an inclined plane is assisted by data processing in a Phyphoxapplication. From the experiment, the result of the moment of inertia value from data processing is 4.89 x 10-4kg.m2, 9.82 x 10-4kg.m2, 12.4 x10-4kg.m2. This research can be used as a teacher reference in teaching the topic of moments of inertia in physics learning at school. This is highly recommended for distance learning during the pandemic so that mastery of concepts is maximized. Further research is suggested that it can be tried to use other materials with other types of rigid bodies to find the moment of inertia. Further references on digital application media to assist learning are also needed considering the dynamic development of technology.