Level, Class, and Prospected Safety Performance of a Lightning Protection System for a Complex of Structures (LPCS)
The Standard IEC 62305 provides advanced information for the design of lightning protection of structures (LPS). In determining the position of the air-termination system, two methods are generally suggested: the protective angle method and the rolling sphere method. Adopting a 3-D graphical simulation, the “rolling sphere” method allows one: to analyze the protected volume at the building roof inside of the rolling ply surface; to verify the behavior of the designed air-termination system; to evaluate the contribution of the surrounding structures in limiting the lightning current flowing in the down-conductors. This current affects the probability of dangerous sparking and the separation distance for the protection of internal installations. This paper presents this approach by a case study of a building in a complex of structures: it highlights particularly the worst cases of the lightning impact related to the designed air-termination system.
Investigation of International Standard, International Electrotechnical Commission, IEC 62305 and Indian Standard IS 2309 in positioning the Air Terminals (ATs)
From 18th Century onwards, many scientists and researchers across the globe have conducted experiments and researches related to the subject called Lightning and as a result they have acquired success in protecting the structures against lightning strokes to a great extent. However, the science behind lightning has not been completely discovered and therefore any design of lightning protection scheme can’t be certified as cent percent safe. Here in this paper, a cuboid equivalent to a rectangular industrial building has been taken into consideration. Lightning Protection Scheme for the same has been designed in two ways: i) based on the Protective Angle Method and Rolling Sphere Method as per International Standard IEC 62305 and ii) based on the Protective Angle Method as per Indian Standard IS 2309. This paper mainly focuses on the comparison of those two designs which ultimately discloses the difference in safety level that we are having by adopting a particular standard.
Fully Integrated Bidirectional CMOS-MEMS Flow Sensor With Low Power Pulse Operation
Leveraging More-than-Moore technology, we demonstrate an integrated CMOS MEMS flow sensor via a very compact system on chip (SoC) that can sense the bidirectional N2 gas flow. Our SoC features a very low-noise instrumentation amplifier that is implemented on a CMOS wafer and serves as a readout integrated circuit for a thermoresistive micro-calorimetric flow sensor which is fabricated on a MEMS wafer. A compact heterogeneous integration is achieved by combining the two wafers via the proprietary InvenSense AlN process. The measured sensitivity of our CMOS MEMS flow sensor is 98 mV/sccm which is three times better than the state-of-the-art counterpart. The flow range measured by our SoC is from −26 to 26 m/s (from −50 to 50 sccm). Moreover, the pulsed heater operation makes this proposed SoC flow sensor a very low power (<9 mW) and, thus, a promising candidate for the Internet-of-Things applications in smart home/green buildings.