Power density

About: Power density is a research topic. Over the lifetime, 9534 publications have been published within this topic receiving 197264 citations. The topic is also known as: volumic power & volume power density.

Potential Sources of Errors in Measuring and Evaluating the Specific Loss Power of Magnetic Nanoparticles in an Alternating Magnetic Field

Abstract: Heat-generating magnetic nanoparticles suspensions are being explored in research and clinical settings as hyperthermia treatment for cancer or as adjuvant in established cancer therapies. In these applications it is essential to use low nanoparticle dosage to prevent any potential side effects including those associated with their accumulation in liver or spleen. Hence, developing particles with superior heating properties continues to remain an active area of research. Specific loss power (SLP), also referred to as specific absorption rate (SAR), represents the power dissipation per unit mass of magnetic nanoparticles in alternating magnetic fields. Accurate measurement of SLP is the key for understanding the parameters that control the heat generation rate, which is required to optimize these systems. However, at presents there are no standards for performing SLP measurements and no accepted calibration materials, making it difficult to compare the performance of various systems reported in literature. Previous work from this group discussed the effect of sample volume and geometry on the SLP data accuracy. In this study, additional analysis and experiments are carried out to investigate the effect of the power dissipation rate, the magnetic properties and the method for temperature slope calculation on the accuracy of the reported power density. Results indicate that when the same heating time is used, the volume at which heat losses become negligible decreases with decreasing sample heating rate. Furthermore, it is shown that for calculating initial temperature slope, a larger error occurs with a longer heating time and higher power level regardless of the curve fitting methods, hence, when power density or heating time increases, a higher order curve fitting (e.g., 2nd polynomial and exponential) is more desirable. In addition, when the magnetization of a nanoparticle suspension is low, the SLP is independent of the sample geometry.

Reaction of neoplasm and brain to laser.

Abstract: LASER is an acronym for light amplification by the stimulated emission of radiation. The laser is an instrument in which atoms are stimulated to emit light in the same phase and direction at a given frequency. The process produces an unidirectional, coherent, intense, monochromatic beam of high energy content. When a solid-state system is utilized, a pulsed, high peak power output is achieved which can be focused through a lens to a spot to produce a maximum in power density. The laser used in the experiments to be reported was such a solid-state unit in which a ruby was employed to emit a wave length of 6,943 Angstroms. The laser head was fitted with a liquid nitrogen cooling system so that a nominal output of 8 joules was delivered over 0.0005 seconds from a maximum energy input of 800 joules at 2 kv. The laser was mounted on a

Porous carbon electrode with conductive polymer coating

Abstract: An extremely high-performance polyaniline electrode was prepared by potentiostatic deposition of aniline on hierarchically porous carbon monolith (HPCM), which was carbonized from mesophase pitch. A capacitance value of 2200 F g −1 of polyaniline was obtained at a power density of 0.47 kW kg −1 and an energy density of 300 Wh kg −1 . This active material deposited on HPCM also has an advantageous high stability. These superior advantages can be attributed to the backbone role of HPCM. This method also has the advantages of not introducing any binder, thus contributing to the increase of ionic conductivity and power density. High specific capacitance, high power and energy density, high stability, and low cost of active material make it very promising for supercapacitors.

A novel aqueous ammonium dual-ion battery based on organic polymers

Abstract: Aqueous dual-ion batteries, one of the latest battery systems, have attracted considerable attention due to their merits of high safety, low cost and environment friendliness except for their high energy density and power density. However, the conventional employment of inorganic electrode materials usually leads to low power density and high cost. Herein, we present a novel aqueous ammonium dual-ion battery (ADIB) with a maximum operating voltage of 1.9 V, in which green and metal-free organic materials such as n-type polyimide and p-type radical polymers serve as anode and cathode, respectively, and 1 M ammonium sulfate solution acts as the electrolyte. During the charging process, the n-type polyimide can combine with cations, while p-type radical polymers can simultaneously accept anions, whereas the cations and anions can reversibly diffuse back to the electrolyte during the discharging process. This ingenious combination makes an assembled ADIB deliver a high energy density of 51.3 W h kg−1 and a maximum power density of 15.8 kW kg−1 (based on the total active weight of both cathode and anode), along with a good cycling stability with 86.4% capacity retention after 10 000 cycles at a current density of 5 A g−1.

Lamp including sulfur

Abstract: A high power lamp which utilzes a lamp fill containing sulfur or selenium, or compounds of these substances. An electrodeless lamp utilizing such a fill at a pressure at least as high as 1 atmosphere is excited at a power density in excess of 50 watts/cc. An arc lamp utilizing the fill at a pressure at least as high as 1 atmosphere is excited at a power density of at least 60 watts/cm.