RANCANGAN SISTEM PENDINGIN DAN VENTILASI PADA HELM MENGGUNAKAN TEKNIK PULSE WIDTH MODULATION BERBASIS MIKROKONTROLER

Helmet or head shield is part of motorized equipment that serves to secure the most vital organs of the head, helmets are required for two-wheeled riders or extreme riders such as racers and so on, helmets protect the head from collision due to accidents or from wind blow if we go with speed high, protects the face from dust, and protects the head from the heat of the sun.Overheating in the sun, lack of air circulation and odor is a common problem, because helmet design is generally tightly closed and unventilated so that the air is difficult to get out and enter and then cause heat. The effects of this effect are tired, stressful and may cause itching of the head due to bacteria and so on. Cooling system and air circulation on a helmet by utilizing cooling fan. As an automatic temperature controller used atmega 32 microcontroller and LM35 temperature sensor. The desired temperature can be set by the user through the setpoint input, thus the user can freely set the desired temperature. Addition of electronic components inserted on the side of the helmet the back of the head. With Pulse Width Modulation technique applied to optimum and precise temperature setting system.

Numerical evaluation of dry-cooling towers interaction in different arrangement

The effect of wind on the performance of dry indirect cooling towers in different arrangements is investigated in the present paper. Thus , there are two cases to solve the problem: At first, solving various arrangements in free conviction state, and then when exposed to wind (forced conviction ).Let consider a wind of 5 m/s velocity in order to compare different results obtained in forced conviction state in various arrangement . For the case of free conviction, towers are considered as two parallel towers, two successive towers, three towers in triangular arrangement and four towers in rectangular arrangement at equal distances. Then, velocity and pressure field are compared in different arrangements and phenomena such as chocking of tower flow due to presence of wind and interactions of various towers on each other's suction capacity in case of wind blow are investigated. Navier-Stokes equations are used in this work.

Vibration Control of Double-Beam System with Multiple Smart Damping Members

A control method to stabilize vibration of a double cantilever system with a set of smart damping blocks is designed and numerically evaluated. The externally controlled magnetorheological sheared elastomer damping block is considered, but other smart materials can be used as well. The robust bang-bang control law for stabilization the bilinear system is elaborated. The key feature of the closed loop controller is the efficiency for different types of initial excitement. By employing the finite element model, the performance of the controller is validated for strong wind blow load and concentrated impact excitement of the particular point of one of the beams. For each of the excitations, the closed loop control outperforms the optimal passive damping case by over 27% for the considered energy metric.

Social Pedagogy under Very Difficult Conditions: The Case of the Multicultural School of Athens

This paper presents social pedagogy under very difficult conditions in the Multicultural School of Athens. More specifically, the paper introduces the Participatory Transformative Pedagogy model developed to train our students to overcome conflicts and to learn to coexist, communicate and gradually to participate to common actions and finally to collaborate effectively. Our efforts aim to introduce cooperation among students that have come from war-torn countries, have suffered a lot and finally meet, in the same school, students ‘responsible for their suffering’; this is the environment of the first multicultural School of Athens. Participatory Transformative Pedagogy (PaTraPe), is a promising approach for making students develop relationships as the only way to deal with the demanding requirements of their classes that value cooperation. When sustainable relationships have been established, social pedagogy methods emerge. The aim of our model is to let a ‘social pedagogical wind’ blow in the Multicultural School of Athens, so that effective communication, community collaboration and social cohesion could be established.