There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

http://ieeexplore.ieee.org/iel5/5610941/5624686/05624745.pdf

Power electronics

The use of microbial fuel cells to generate electrical current is increasingly being seen as a viable source of renewable energy production In this Progress article, Bruce Logan highlights recent advances in our understanding of the mechanisms used by exoelectrogenic bacteria to generate electrical current and the important factors to consider in microbial fuel cell design There has been an increase in recent years in the number of reports of microorganisms that can generate electrical current in microbial fuel cells Although many new strains have been identified, few strains individually produce power densities as high as strains from mixed communities Enriched anodic biofilms have generated power densities as high as 69 W per m2 (projected anode area), and therefore are approaching theoretical limits To understand bacterial versatility in mechanisms used for current generation, this Progress article explores the underlying reasons for exocellular electron transfer, including cellular respiration and possible cell–cell communication

Exoelectrogenic bacteria that power microbial fuel cells

Solar Engineering Of Thermal Processes

Buildings are a major primary energy consumer in the world energy sector, with a value of about 40% of total energy consumption. The absence of traditional sources of energy currently promotes the development of Net Zero Energy Buildings (NZEBs). The general definition of net zero energy construction is very critical to grasp. The aim of the paper is to overview the literature on the existing NZEB to make them self-sustaining and net zero in order to improve energy efficiency of the buildings. If enough renewable energy could be used, NZEB could potentially be achievable with power production. Furthermore, different building-service systems utilizing renewable energy sources have been extensively investigated for possible uses in NZEB. The paper gives the detail of its climatic condition in various part of the world along with their consequences and its impacts. The NZEB concept will significantly define the demand and supply strategies for renewable energies and conversion accounting to achieve a NZEB target along with its renewable energy evaluation. Buildings account for a large proportion of the world's total energy and carbon emissions, and play an important role in formulating strategies for sustainable growth. To this end, smart systems implement applications with numerous and interdisciplinary features. Here, the paper gives a detailed literature review on NZEB. 

Concept of net zero energy buildings (NZEB) - A literature review

Nine-phase hex-tuple inverter for five-level output based on double carrier PWM technique

A new L-L Multilevel Boost Converter (L-LMBC) topology for high gain renewable energy applications is proposed in this work. L-LMBC topology is designed to provide an operative solution for renewable energy applications which requires a high voltage conversion ratio and stack of the capacitor; such as a photovoltaic (PV) system with a Multilevel Inverter (MLI), electrical drives, automotive, hybrid electric cars etc. The proposed topology is derived by attaching the Cockcroft Walton (CW) multiplier to an upper L-converter of the LL topology of XY family. The mode of operation of L-LMBC with mathematical equations is also discussed in details. The noticeable features of proposed L-LMBC topology are: i) Only one power control switch; ii) High inverting output voltage from single input source; iii) Without the use of transformer; iv) The number of CW multiplier levels can be added to achieve high voltage without changing the connection of main circuits. The Matrix Laboratory (MATLAB) simulation results are provided and the result validates the functionality, feasibility and design of the converter.

L-L multilevel boost converter topology for renewable energy applications: A new series voltage multiplier L-L converter of XY family

This work focused on a harmonic mitigating filter and investigated the effect of the harmonic mitigating filter in the textile industry with innovative energy conservation strategies for energy bill reduction, which covers a pathway to climate change mitigation. Here, the effect of the harmonic filter is found out by the systematic energy audit methodology (Preliminary, Detailed and Post-Audit phase). From the energy auditing, it has been found that the textile industry needed a passive harmonic filter for harmonic mitigation. Since, third, fifth, and seventh order of harmonic predominantly exists in the system. The high stability at higher current, known tuning frequency, low cost and low power consumption makes the passive filter to be the best fit for the system. The voltage and current Total Harmonic Distortion Factor (THDF) have been measured using the class ‘A’ power quality and energy analyzer. The harmonic filter’s effect in harmonics mitigation is prominent; 66.45% of the reduction of current harmonics which is achieved after installing the passive filter at the Point of Common Coupling (PCC) of the system. Also, the reduction of harmonics ensures energy conservation through the reduction of additional losses (joule, copper and eddy current losses). The techno-economic analysis with payback period calculation is carried out and reported. Also, the effect of harmonics like mechanical anomalies (temperature rise) is carefully studied using an infrared thermo graphic technique in the textile industry’s motor loads. The energy conservation and their carbon emission reduction are calculated and reported.

/pdf/energy-conservation-approach-for-continuous-power-quality-4sh6z4sbat.pdf

Energy Conservation Approach for Continuous Power Quality Improvement: A Case Study

The enduring life span of the machine insulation will be decided based on degradation level in motor and generator stator windings The non-destructive diagnostic tools like dielectric loss and capacitance test and partial discharge (PD) analysis, recognized to access the deterioration in the insulation system of rotating machines The experiments reveal various characteristic parameters such as leakage current, dielectric dissipation factor, the capacitance value, and PD magnitude The integrity of the rotating machine can be find out by analyzing these parameters This research study shows the hybrid method for prediction of insulation condition in the stator winding by utilizing the artificial neural network (ANN) with gravitational search algorithm in comparison with ANN and ANN-genetic algorithm The advent of expert systems ensures the quality assurance and service life assessment of the high-voltage assets It offers a predictive maintenance solution to personnel dealt with power utilities thereby increasing the uptime, reliability, and productivity, which in turn reducing the operating costs, downtime and unplanned outages For testing and predicting the insulation status, several 11 kV machines are considered The predicted results using hybrid techniques extend a close agreement with reference to the data obtained from the experiments performed The proposed method indicate the competent and trustworthy, by the presented test results

/pdf/insulation-condition-assessment-of-high-voltage-rotating-1i96u27xh2.pdf

Sanjeevikumar Padmanaban

Papers

Concept of net zero energy buildings (NZEB) - A literature review

Nine-phase hex-tuple inverter for five-level output based on double carrier PWM technique

L-L multilevel boost converter topology for renewable energy applications: A new series voltage multiplier L-L converter of XY family

Energy Conservation Approach for Continuous Power Quality Improvement: A Case Study

Insulation condition assessment of high-voltage rotating machines using hybrid techniques