Although lightning rods have long been used to limit damage from lightning, there are currently no American standards for the shape and form of these devices. Following tradition, however, sharp-tipped Franklin rods are widely installed despite evidence that, on occasion, lightning strikes objects in their vicinity. In recent tests of various tip configurations to determine which were preferentially struck by lightning, several hemispherically tipped, blunt rods were struck but none of the nearby, sharper rods were ''hit'' by lightning.Measurements of the currents from the tips of lightning rods exposed to strong electric fields under negatively charged cloud bases show that the emissions consist of periodic ion charge bursts that act to reduce the strength of the local fields. After a burst of charge, no further emissions occur until that charge has moved away from the tip. Laboratory measurements of the emissions from a wide range of electrodes exposed to strong, normalpolarity thunderstorm electric fields show that positive ions are formed and move more readily over sharp-tipped electrodes than over blunter ones. From these findings, it appears that the electric field rates of intensification over sharp rods must be much greater than those over similarly exposed blunt rods for the initiation of upwardgoing leaders.Calculations of the relative strengths of the electric fields above similarly exposed sharp and blunt rods show that although the fields, prior to any emissions, are much stronger at the tip of a sharp rod, they decrease more rapidly with distance. As a result, at a few centimeters above the tip of a 20-mm-diameter blunt rod, the strength of the field is greater than that over an otherwise similar, sharper rod at the same height. Since the field strength at the tip of a sharpened rod tends to be limited by the easy formation of ions in the surrounding air, the field strengths over blunt rods can be much stronger than those at distances greater than 1 cm over sharper ones.The results of this study suggest that moderately blunt metal rods (with tip height-to-tip radius of curvature ratios of about 680:1) are better lightning strike receptors than are sharper rods or very blunt ones.
This chapter discusses the internal provisions of Article XXIV of the General Agreement on Tariffs and Trade (GATT) or the requirement for regional members to eliminate ‘other restrictive regulations of commerce’ (ORRC). It considers the definitional possibilities for this term as it may apply to the domestic regulations of RTA members and examines the textual context and the limited WTO Panel and Appellate Body treatment. It concludes that ORRC has a limited reach for domestic regulations and that the duty to eliminate other restrictive regulations of commerce only extends to domestic laws of an RTA member that offer less favourable treatment to products of another regional member.
due to the disaster-related causes, such as worsening condition of the injuries and health after the earthquake. More than four years later, about 230,000 people remained evacuated from the affected areas. The Japanese government has placed the total cost of the disasters at $309 billion. Japan is known as the "earthquake" capital of the world. Although the regularity of earthquakes in Japan has motivated the country to invest in building quake-resistant structures, prepare plans for emergency evacuation, and conduct research on earthquakes, the Great East Japan Earthquake was beyond imagining, beyond preparation. Recovery will take decades.
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