Page 1 of 15 - About 142 Essays
  • Operating Principles In PEM Fuel Cell

    The Nafion membrane belongs to a class of poly-perfluoro-sulfonic acids, and consists of a hydrophobic tetrafluoroethylene backbone with pendant side-chains of perfluoronated vinyl-ethers terminated by sulfonic acid groups. Proton conductivity in Naffion and most other polymer electrolytes increases with the water activity and that is the main reason to humidify the incoming gas reactants. Sufficient water must be absorbed into the membrane to ionize the acid groups, whereas excess water can flood the cathode of the fuel cell, diminishing fuel cell performance and limiting the power…

    Words: 1940 - Pages: 8
  • The Function Of OLED (Organic Light Emitting Diode)

    OLEDs can include either two levels or three levels of natural material; in the last design, the third layer aids transport electrons from the cathode to the emissive…

    Words: 1005 - Pages: 5
  • Floating Slimes Essay

    Silver, lead, arsenic, bismuth, antimony, selenium, and nickel are common impurities existing in copper anodes. Some impurities dissolved from the anodes can precipitate, if their concentrations in the electrolytic solution are above saturation levels. Some of these precipitates can settle down but some are floating slimes and can be a source of cathode contamination by their incorporation into the cathode 16. These floating slimes are amorphous and typically have compositions of Sb-As-O and…

    Words: 1864 - Pages: 8
  • Ptfe Lab Report

    in 0.1 M HClO4 solution, saturated with oxygen by bubbling pure oxygen gas for 30 min. In order to evaluate the electrochemical stabilities of the Pt and PtFeS catalysts, the accelerated durability test (ADT) was performed by cycling cathode potential between 0.6 and 1.0 V vs. RHE at a sweep rate 50 mV/s for 3,000 cycles during the CV measurement. LSV for the ORR and CV were recorded at before and after 3,000 cycles. 2.3 Evaluation of MEA performance Membrane electrode assemblies (MEAs) used in…

    Words: 1386 - Pages: 6
  • Electrolyte Concentration Lab Report

    random errors, which caused the results to be unreliable. Due to this, the raw data does not support the hypothesis. Thus, a line of best fit was drawn in order to reduce the effect of random errors, and statistically remove the outliers, to give a better representation of what the results should have been. This line of best fit suggests that the current flow through the copper electrodes increased as the electrolyte concentration increased, supporting the hypothesis, and corresponding to the…

    Words: 2152 - Pages: 9
  • Synthesis Of L-Ion Battery

    surface free energy, undesirable side reactions, including electrolyte degradation, consequently, high irreversible capacity loss during cycles easily occur on the In2O3 NC surface. Herein, these problems have been overcome polymerization by cross linking molecule terephtalic acid (TPA) or π-conjugated molecule (EBA). In addition, the synthetic procedure is simple, low-cost, and straightforward without any separate assembly process. The In2O3 NC hybrid π-conjugated EBA molecule shows excellent…

    Words: 1257 - Pages: 6
  • Compare The Construction And Operation Of A Ni-Cad Battery With A Lead-Acid Battery

    Q1. Describe the construction and operation of a Ni-Cad battery. Compare and contrast the Ni-Cad battery with a Lead-Acid battery. a. Construction: figure 1. Ni-cad battery construction Ni-Cad battery refers to Nickel-cadmium battery which is widely used in industrial world. Basically, the Ni-Cad battery consists of positive and negative plates, separators, electrolyte, cell vent, and cell container. The positive plate in Ni-Cad battery is Nickel Hydroxide Ni(OH)2. However, the negative…

    Words: 1065 - Pages: 5
  • Capacitance Properties Of Polyaniline Essay

    Capacitance properties of electrodeposited polyaniline films on stainless steel substrate. A.A. Al-Owais1,I. S. El-Hallag2, M.A. Ghanem3 1,3Chemistry Department, Faculty of Science, King Saud University, Riyadh ,SA 2Chemistry Department, Faculty of Science, Tanta University, Tanta, 31527, Egypt Abstract. Polyaniline (PANI) thin films were successfully synthesized from a mixed solution of 1M aniline and two different concentration solutions of H2SO4 on a stainless steel substrate. The…

    Words: 1807 - Pages: 8
  • Philo Farnsworth's Impact On Society

    Alexander Graham Bell wanted to upgrade the telephone and make it transmit images. Also to top it off, light was already being used it would be easier for one to make the “Photophone”. (The Invention of Television) As earlier said Philo Farnsworth won an award for a fool proof car ignition switch. This was from the Science and Invention Magazine, and this probably started his interest in electronics and technical machines. (Farnsworth, Philo) Now it is the 1900’s and people have stopped chasing…

    Words: 1602 - Pages: 7
  • Watching Television Benefit American Culture

    For many Americans TV is essential for life. Like water it is something that is needed to go throughout the day. But, what is the effect that this is having on one’s mind, body, and family? Is the joy of the television for those 5 hours’ worth it? TV has many effects that do not benefit American culture; this includes bad health, not being productive, the thought processes one has. Watching TV is bad for one’s health. So many Americans have been turned into couch potatoes. Figure one is…

    Words: 1055 - Pages: 4
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