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What are architectural acoustics?
Published in Samuel L. Hurt, Building Systems in Interior Design, 2017
Another important effect worth noting is that air can absorb high frequencies (say above 2,000 Hz or so) but it cannot absorb low frequencies. This is the reason that thunder is heard as a low pitched sound although a nearby lightning strike includes sounds of many frequencies; it is actually the same sound, but when it is far away, the air absorbs much of the high frequency component, leaving only the low frequency “rumbling.”
Storm Lightning Damage
Published in Randall Noon, Introduction to Forensic Engineering, 2020
Thunder is heard no more than about 16 miles from the originating lightning strike. Further, most lightning occurs from cloud to cloud, rather than from cloud to ground. It is estimated that 85 percent of all lightning is cloud to cloud. Thus, even reports of thunder in an area are not proof that lightning was close enough to have caused damage.
What Is Science For?
Published in Yongyuth Yuthavong, Sparks from the Spirit, 2018
With science as a source of knowledge and of methods for problem solving, we can see that it serves an ultimate purpose as a quality that promotes our intellect and wisdom in many ways. What we take in through our senses are information and experiences, which we note, learn, and compare with former information and experiences, enabling us to understand the situation at a certain level. Science helps us understand various issues about nature much more thoroughly than our experiences alone because it processes information not only from a single person but also from various sources through systematic investigation over a long period of time. For example, we understand at a certain level that a thunderstorm is a natural phenomenon, a seasonal occurrence. Societies mired in superstition or prescientific beliefs such as those in past history would give different explanations. Some societies believe thunder comes from the wrath of gods. In Greek mythology, lightning and thunder are weapons given to the god Zeus by the one-eyed cyclopes. Many societies in the East have a legend that lightning is due to glitters from a precious glass held by a fairy named Mekla teasing a demon named Ramasura. The sound of thunder comes from the axe thrown by Ramasura in pursuit of both Mekla and the glass. These stories serve as alternative explanations of natural phenomena, valued as parts of cultures of various societies. A scientific explanation of lightning and thunder is based on systematic observation and experiments and forms part of large accounts of physical phenomena that enable us to understand nature in both broad and deep aspects. We can understand that rain comes from clouds, which are composed of water vapor derived from water sources on the earth. Science tells us further that lightning and thunder are phenomena derived from movement of charges in the clouds and the atmosphere. The charges are created by a process that is still not completely understood, generally involving collision between supercooled cloud droplets and small ice crystals moving upward and the larger-size graupel (soft hail) moving downward. The upper parts of the clouds tend to be positively charged and the lower parts negatively charged. The flashes of lightning are traces of the moving charges recombining with one another in the sky or between the sky and the earth, which can be so violent that the air around them expands, and when it collapses it creates the loud sound of thunder.
A failure prediction method of power distribution network based on PSO and XGBoost
Published in Australian Journal of Electrical and Electronics Engineering, 2022
Jian Fang, Hongbin Wang, Fan Yang, Kuang Yin, Xiang Lin, Min Zhang
In windy weather, it is easy for power distribution networks to contact surrounding trees or be hooked by foreign matters so as to cause single-phase ground failure. In continuous rainy days, the increase in humidity may affect the insulation performance of the equipment, leading to leakage of current or pollution flashover. Under the action of thunder and lightning, power distribution network-related equipment may suffer overvoltage, current leakage or other failures due to lightning stroke. Therefore, this paper mainly selects weather indexes including gale, precipitation, thunder and lightning as the input of the failure risk prediction model, as shown in Table 2.