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Nikola Tesla (1856-1943) was an American-Croatian electrical engineer who studied at Graz and Prague. He emigrated to the USA in 1884, where he worked for Thomas Edison. After a period of time, apart from having differences of opinion, Edison did not pay him the promised remuneration, so he left the job and set up on his own. Soon, Tesla promoted alternating current (AC) and invented his AC induction motor, which eliminated commutator and sparking brushes needed for direct current (DC) motors favored by Edison. During the early years of electricity, there was one problem: DC was not easily converted to higher or lower voltages. Tesla believed that AC could be converted to different voltages relatively easily using a transformer. He also made substantial improvements in the field of AC power transmission and generation, realizing that it could be generated and transmitted far more effectively than the commonly used DC. He patented his inventions and set up a partnership with George Westinghouse. His interest then shifted to developing a high-frequency and high-voltage Tesla coil with an air-core transformer, and he achieved this in 1899. He even made a device that could transmit power without intervening wires by using the earth as a transmitting oscillator. He was increasingly interested in transmitting power over large distances., (© Journal of the Association of Physicians of India 2024.)

Exploring changes of building energy consumption and its relationships with climate can provide basis for energy-saving and carbon emission reduction. Heating and cooling energy consumption of different types of buildings during 1981-2010 in Tianjin city, was simulated by using TRNSYS software. Daily or hourly extreme energy consumption was determined by percentile methods, and the climate impact on extreme energy consumption was analyzed. The results showed that days of extreme heating consumption showed apparent decrease during the recent 30 years for residential and large venue buildings, whereas days of extreme cooling consumption increased in large venue building. No significant variations were found for the days of extreme energy consumption for commercial building, although a decreasing trend in extreme heating energy consumption. Daily extreme energy consumption for large venue building had no relationship with climate parameters, whereas extreme energy consumption for commercial and residential buildings was related to various climate parameters. Further multiple regression analysis suggested heating energy consumption for commercial building was affected by maximum temperature, dry bulb temperature, solar radiation and minimum temperature, which together can explain 71.5 % of the variation of the daily extreme heating energy consumption. The daily extreme cooling energy consumption for commercial building was only related to the wet bulb temperature (R2= 0.382). The daily extreme heating energy consumption for residential building was affected by 4 climate parameters, but the dry bulb temperature had the main impact. The impacts of climate on hourly extreme heating energy consumption has a 1-3 hour delay in all three types of buildings, but no delay was found in the impacts of climate on hourly extreme cooling energy consumption for the selected buildings.

The history of energy sources used in surgery is inextricably linked to the history of electricity. Milestones include identification of safe electrical waveforms that can be used in the human body, patient isolation to prevent alternate-site burns, bipolar energy sources to negate capacitance injuries, laser energy, and the combination vessel sealing devices commonly used today. Engineering efforts to eliminate many of the hazards of electrosurgery are critical to how we practice modern gynecologic surgery. The introduction of bipolar instruments, increasing the safety of monopolar electrosurgery by not using hybrid trocars, and introduction of active shielding of the instruments from stray radiofrequency energy using intelligent secondary conductors have led to the re-emergence of electrosurgery as the universal surgical energy source. The low ongoing costs and the presence of electrosurgical generators in all hospitals readily enables electrosurgery to be the mainstay. Expensive lasers are confined to specialized centers, where they continue to be used, but for a long while filled a gap created by complications of electrosurgery. Sophisticated power sources continue to be introduced and include the ultrasonic scalpel, plasma surgery, and various devices for sealing vessels, all of which have advantages and disadvantages that are recognized as they begin to be subjected to scientific validation in randomized trials., (Copyright © 2013 AAGL. Published by Elsevier Inc. All rights reserved.)

The 1930s witnessed an intense struggle between gas and electricity suppliers for the working class market, where the incumbent utility—gas—was also a reasonably efficient (and cheaper) General Purpose Technology for most domestic uses. Local monopolies for each supplier boosted substitution effects between fuel types—as alternative fuels constituted the only local competition. Using newly-rediscovered returns from a major national household expenditure survey, we employ geographically-determined instrumental variables, more commonly used in the industrial organization literature, to show that gas provided a significant competitor, tempering electricity prices, while electricity demand was also responsive to marketing initiatives.

An astute diplomat, Alessandro Volta secured the patronage of Napoleon Bonaparte to promote his rise to fame as an electrical expert. Reciprocally, politicians helped their own causes by presenting him as a national as well as a scientific figurehead.

In mid-1960, our group initiated a research program focused on studying pain-free electromagnetic methods of furnishing energy to an implanted heart without piercing the skin. During the last half of 1960, we derived a detailed theoretical rationale for a radio frequency system involving inductive coupling between a thin, small, pancake-shaped coil on the surface of the chest and a similar coil either within the chest or, alternatively, subcutaneously. Having an efficiency of about 95%, the system was evaluated in dogs at 50 and 69 W levels, respectively. Thus was born what is now termed the transcutaneous energy transformer (TET).

Carbon particle analysis was performed on a dated sediment core from Lake Erie in order to explore the inputs of pollution from incomplete combustion of coal, oil, and wood. Carbon particles were isolated from the sediment by chemical digestion, and elemental carbon content was determined by CHN analysis. The type of carbon particle (from burning coal, oil, and wood) and particle size and relative abundance were determined using scanning electron microscopy on 100 particles from each core section. The elemental carbon content in the Lake Erie core ranges from 2.5 to 7.4 mg of carbon/g of sediment (1850-1998), and the maximum carbon content in the sediment occurs in the late 1960s to early 1970s. It is shown that particle mass is a better predictor than particle number of historical energy consumption records. This is especially clear for wood where variable particle volumes play a significant role in determining the record of elemental carbon mass from wood burning. Lake Erie core's content of total carbon and carbon particle type is in agreement with U.S. energy consumption records, except that a wood maximum occurs during 1905-1917, about 36 yr after the U.S. consumption maximum from 1870 to 1880.

The methods of surgical treatment of nasal spetum deformations by electrical instruments in the XIX century were used especially in United States of America. In the begining of seventieth of the XIX century D.H. Goodwillie used the machine by foot. In the half of eightieth of the XIX century and later the nasal trephine was used by C. Astier, W. Wróblewski, J. Wright, M. Schmidt, J. Wolff, F. Kretschmann and others, G. Spiess employed the special protected speculum. The special saws were also in prewailing use (G. Spiess and others). Those methods were generally not many effective.

The high-speed air turbine handpiece is currently used for most dental cutting procedures and has been in widespread use for more than thirty years. Although reports of its historical background have been previously published these have not dealt with all relevant developments and some inconsistencies exist. The history of the development of turbines and their application in dental cutting systems from the late 19th century to the present day is now reviewed. An historical account of the recognition of benefits that may accrue from rotary cutting at increased speeds is given and the various attempts that have been made to design equipment capable of high speeds are discussed. Consideration is given to the development of non-rotary cutting devices, as is the failure of these adequately to replace the air turbine handpiece for routine work. It is concluded that the air turbine handpiece will continue to hold a leading position in the field for some years to come but that future improvements would be facilitated by the development of an understanding of the theoretical aspects of its behaviour.

The lithium/iodine-polyvinylpyridine battery, first implanted 20 years ago, has become the power source of choice for the cardiac pacemaker. Over the last 20 years, improvements in cell chemistry, cell design, and modeling of cell performance have been made. Cells today exhibit an energy density over three times as great as cells produced in 1972. Well over 2 million pacemakers have been implanted with this chemistry, and the system has exhibited excellent reliability.