Current Issue : October-December Volume : 2021 Issue Number : 4 Articles : 5 Articles
This paper introduces a small-area, low-power delta-sigma DAC that can support power line carrier communication. In order to achieve the oversampling ratio of 128, a three-stage cascaded half-band filter is utilized. An optimized sturdy MASH ΔΣ modulator was used to avoid instability caused by high-order shaping and reduce the area at the same time. The postanalog reconstruction includes a switched-capacitor DAC (SC DAC) and a 4-tap FIR/IIR hybrid filter, which not only meets the requirements of low power but also promotes the out-of-band SNR. The final chip is fabricated in a 55 nm CMOS process, occupies 0.08mm2, and consumes 1.5mW of analog power at 2.5V supply. The simulation results show that the dynamic range is 85.7 dB, while the out-of-band SNR is 40.5 dB....
Power factor (PF) is simply an expression of energy efficiency, which is always expressed in terms of percentage. Technically, PF is a ratio of real power in Kilowatts to the apparent power, which is always expressed in kilovolts amperes. In AC power analysis, power is always expressed in three ways, the real power (P), reactive power (Q), and the apparent power (S ). The real power is the work useful power, while the reactive power is the wasted power in the 3-phase AC system, and the apparent power is the vectorial sum of the two powers. The increase of reactive power will reduce the presence of real power, thus making the power to be more expensive. In this paper, we will analyze the importance of improving the power factor by applying a bank of capacitors to a case study in Lebanon. Analysis of the economic improvement in the application of power factor correction is carried out. The result shows a reduction of 12 percent in the total cost....
Due to the increasing demand for battery electric vehicles (BEVs), the need for vehicle battery raw materials is increasing. The traction battery (TB) of an electric vehicle, usually a lithiumion battery (LIB), represents the largest share of a BEV’s CO2 footprint. To reduce this carbon footprint sustainably and to keep the raw materials within a closed loop economy, suitable and efficient recycling processes are essential. In this life cycle assessment (LCA), the ecological performance of a waterjet-based direct recycling process with minimal use of resources and energy is evaluated; only the recycling process is considered, waste treatment and credits for by-products are not part of the analysis. Primary data from a performing recycling company were mainly used for the modelling. The study concludes that the recycling of 1 kg of TB is associated with a global warming potential (GWP) of 158 g CO2 equivalents (CO2e). Mechanical removal using a water jet was identified as the main driver of the recycling process, followed by an air purification system. Compared to conventional hydro- or pyrometallurgical processes, this waterjet-based recycling process could be attributed an 8 to 26 times lower GWP. With 10% and 20% reuse of recyclate in new cells, the GWP of TBs could be reduced by 4% and 8%, respectively. It has been shown that this recycling approach can be classified as environmentally friendly....
Two sets of Organic dyes were developed using kassod and senna plant leaves. The first sets of dyes are the organic dye from the leaves of two plants while the second set is the dye produce after combining together the dyes from the kassod and senna plants leaves. The two sets of dyes were used to sensitize the grown films. The films were characterized and the current voltage values of the grown films were obtained. The solar simulation result of the grown film for Kassod dyed TiO2 film was recorded for single dyes and for the combination of the two dyes. The result also covers absorbance of the spectra lines, absorbance coefficient values of the dyed TiO2, as well as transmittance and energy band gap values of the developed films. The precursors of tin (IV) chloride (SnCl4) (60%) and hydrofluoric acid (40%) was deposited on the cleaned soda-lime glass using the chemical vapour deposition method and nitrogen gas was supplied as a carrier gas through the bubbler to form the FTO layer. Titanium dioxide paste (TiO2) was deposited using a screen printing method to form M-TiO2....
With expanding environmental and climate change regulatory frameworks, the fossil-based baseload generation is forced to decline, thus making room for more and more generation based on renewable and other carbon-free energy sources. This paper deals with a number of controversial issues and open questions concerning the growing penetration of renewable energy sources into power generation systems, often without due care of the impacts of variable as compared to conventional generation on the reliability of electricity supply. Particular attention is paid to baseload generation, power market design, system operation under extreme weather conditions, energy storage, back-up, and reserve power, as well as to the role of mechanical inertia and reliability of on-site fuel supply, demonstrated on an example of coal excavation and delivery to a power plant....
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