Latent heat is the most important property for phase change material (PCM) as thermal energy storage material. It is closely related to the internal properties of the material. The aim of this article is to examine th...
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Latent heat is the most important property for phase change material (PCM) as thermal energy storage material. It is closely related to the internal properties of the material. The aim of this article is to examine the effect of multi walled carbon nanotube (MWCNT) on the microstructural and thermal properties of a paraffin based PCM and their influence on energy storage. Thermal stability, functional group and morphology of a pure PCM and MWCNT mixed PCM have been analysed using DSC, FTIR, and FESEM, respectively. Microstructural observation shows that MWCNT is homogeneously incorporated into the PCM matrix. FTIR spectra of pure and MWCNT mixed PCM are similar, indicating that there was no chemical interaction. It was found from DSC result that MWCNT/RT44HC composite PCM shows a 2.7% increase in latent heat of fusion. The newly introduced composite material is suitable for energy storage in solar thermal and solar photovoltaic thermal applications.
Proton exchange membranes based on perfluorosulfonic acid (PFSA) ionomers are the industry standard for proton exchange membrane fuel cells. These ionomers offer remarkable proton conductivity and chemical stability, ...
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Proton exchange membranes based on perfluorosulfonic acid (PFSA) ionomers are the industry standard for proton exchange membrane fuel cells. These ionomers offer remarkable proton conductivity and chemical stability, especially when fully hydrated with water. Performance, however, rapidly decreases as the membranes dry out, thereby requiring external humidification equipment. Because of this, there exists a need for new ionomers that can maintain high proton conductivity at low humidification levels. Perfluoro bissulfonimides have acid strengths similar to those of sulfonic acids and can be used to extend the polymer side chain with an additional protogenic group. These polymers have been designated PerfluoroSulfonImide Acid (PFIA) or PerfluoroIonene Chain Extended (PFICE) ionomers. Compared to PFSAs, these ionomers have improved conductivities under all humidity conditions, however, the benefit of these improvements are most significant under the driest conditions.
Improvement of existing and development of new methods of formation and signal processing, aimed at improving stealth and energy efficiency is a promising direction of research in the field of information security. Th...
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ISBN:
(纸本)9781538606377
Improvement of existing and development of new methods of formation and signal processing, aimed at improving stealth and energy efficiency is a promising direction of research in the field of information security. The proposed method of multi-channel transmission of information by converting PCM (pulse code modulation) signals in the positional code-switching signals (PCS) with subsequent manipulation of pseudoephedrine sequences. This method allows to increase the energy efficiency and secrecy in the transmission of digital signals, which is particularly relevant for information system (IS) special purpose.
In this paper, we propose a simplified way of voice communication over Wireless Local Area Network (WLAN) using Internet Protocol, without using internet connectivity at any end in enclosed system. A voice signal is c...
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ISBN:
(纸本)9781509048748
In this paper, we propose a simplified way of voice communication over Wireless Local Area Network (WLAN) using Internet Protocol, without using internet connectivity at any end in enclosed system. A voice signal is converted into an electrical signal using a microphone and this analog signal will be converted into a digital signal using appropriate quantization level and sampling rate. This digital data is then transmitted over the WLAN network using internet protocol in certain defined packet size, i.e. 8 bit digital packet. At the receiver's end, packets passed through WLAN are received as is, which are combined and converted back to the transmitted analog signal from transmitter's end. These signals can be combined into sound signal through a speaker connected with receiving computer. This method of communication over internet protocol is generally called VoIP, i.e. Voice over Internet Protocol. This method can replace the current PBX telephonic network inside organizations. The demonstration of this mode of communication has been successfully done on institute WLAN with the VoIP server.
This describes one approach to investigating an unknown IRIG 106, Chapter, 4 Class I or Class II pulse code modulation (PCM) format. The assumption is that you are supplied with decrypted data and clock signals for th...
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This describes one approach to investigating an unknown IRIG 106, Chapter, 4 Class I or Class II pulse code modulation (PCM) format. The assumption is that you are supplied with decrypted data and clock signals for the unknown PCM stream. This technique is optimized for 16, 12, or 8-bit Word Minor Frames. Standard IRIG 106, Appendix C, Table C-1, Frame Synchronization (Frame Sync) values of 32, 24, 16-bit patterns are simpler to investigate. Other IRIG Frame Sync patterns can also be investigated, but are not dealt with in this document. This document will utilize a sample 24-bit Frame Sync pattern, because it will produce Endian issues in the recorded data.
The Range Commanders Council has been attempting to standardize Telemetry over IP (TMoIP) for many years now. While the attempt has been valiant, the outcome to date has not been very successful. As a result, many ven...
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The Range Commanders Council has been attempting to standardize Telemetry over IP (TMoIP) for many years now. While the attempt has been valiant, the outcome to date has not been very successful. As a result, many vendors have implemented their own proprietary methods for sending PCM data over IP networks resulting in a lack of interoperability. As telemetry ground stations are finally making the move toward network centric architectures, it is worth considering the lessons learned over the previous 10 years of designing, installing, troubleshooting and optimizing telemetry data distribution over IP networks. This paper describes a proposed revision to IRIG 218 based on these real life experiences. It discusses the critical decisions and architectural decisions to be made and some of the pitfalls to be avoid.
We analyze the achievable information rates (AIRs) for coded modulation schemes with quadrature amplitude modulation constellations with both bitwise and symbolwise decoders, corresponding to the case where a binary c...
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NASA Technical Reports Server (Ntrs) 19990004344: Conversion from Engineering Units to Telemetry Counts on Dryden Flight Simulators by NASA Technical Reports Server (Ntrs); published by
NASA Technical Reports Server (Ntrs) 19990004344: Conversion from Engineering Units to Telemetry Counts on Dryden Flight Simulators by NASA Technical Reports Server (Ntrs); published by
NASA Technical Reports Server (Ntrs) 19860005008: Analog Fm/Fm Versus Digital Color Tv Transmission Aboard Space Station by NASA Technical Reports Server (Ntrs); published by
NASA Technical Reports Server (Ntrs) 19860005008: Analog Fm/Fm Versus Digital Color Tv Transmission Aboard Space Station by NASA Technical Reports Server (Ntrs); published by
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