scholarly journals Development of a longevous two-species biophotovoltaics with constrained electron flow

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Huawei Zhu ◽  
Hengkai Meng ◽  
Wei Zhang ◽  
Haichun Gao ◽  
Jie Zhou ◽  
...  
Keyword(s):  
Power Density ◽  
Microbial Consortium ◽  
Electron Flow ◽  
Average Power ◽  
Stable Operation ◽  
Temporal Separation ◽  
Photosynthetic Microorganisms ◽  
Light Absorbers ◽  
Medium Replenishment ◽  
Power Densities

Abstract Microbial biophotovoltaics (BPV) offers a biological solution for renewable energy production by using photosynthetic microorganisms as light absorbers. Although abiotic engineering approaches, e.g., electrode modification and device optimization, can enhance the electrochemical communication between living cells and electrodes, the power densities of BPV are still low due to the weak exoelectrogenic activity of photosynthetic microorganisms. Here, we develop a BPV based on a d-lactate mediated microbial consortium consisting of photosynthetic cyanobacteria and exoelectrogenic Shewanella. By directing solar energy from photons to d-lactate, then to electricity, this BPV generates a power density of over 150 mW·m−2 in a temporal separation setup. Furthermore, a spatial-temporal separation setup with medium replenishment enables stable operation for over 40 days with an average power density of 135 mW·m−2. These results demonstrate the electron flow constrained microbial consortium can facilitate electron export from photosynthetic cells and achieve an efficient and durable power output.

scholarly journals Investigation of Radio-frequency Power Density Distribution around GSM Mast in Keffi Town, Nigeria

2019 ◽  
pp. 1-6
Author(s):  
Umaru Ibrahim ◽  
Musa Mohammed ◽  
Idris Mohammed Mustapha ◽  
Abdullahi Abubakar Mundi ◽  
Idris Yahaya
Keyword(s):  
Density Distribution ◽  
Radiation Exposure ◽  
Power Density ◽  
Average Power ◽  
Base Stations ◽  
Power Density Distribution ◽  
The People ◽  
Power Densities ◽  
Frequency Power ◽  
Mobile Base

In this study, an investigation of radiofrequency power density distribution around GSM mast in Keffi town, Nigeria was determined. Radiofrequency meter (Electrosmog ED- 155A) was used to measure the EM radiation at 50, 70, 90,110, 130, 150, 170, and 190 m away from mobile base stations. A total of fifteen mobile base stations were randomly selected in Keffi town covering about four network providers (MTN, Globacom, Etisalat, and Airtel), according to their proximity to buildings, number of antennas mounted on their masts, how close they are to other base stations and the population density around them.The result reveal that MBS5 was found to have the highest value of average power density compared to that of the remainder, with a contribution of about 16% (2908.38 µW/m2). The least contribution was recorded in MBS3 with only about 1% (173.71 μW/m2). The other MBS with significant contribution are MBS6 (15%), MBS11 (15%), MBS10 (13%), MBS8 (13%) and MBS13 (11%) with average power densities of 2878.72μW/m2, 2767.28μW/m2, 2385.43 μW/m2, 2382.70 μW/m2, and 1996.36 μW/m2 respectively. The findings reveal that the measured values of power densities across all the sites are well below the RF radiation exposure safety limit set by International Commission on Non-ionizing Radiation Protection (ICNIRP) when compared with the findings in this study. Therefore, RF radiation exposure from mobile base stations in Keffi town may pose no health risk to the people living within the area.

Analysis of RF Radiation and its Health Effects in Lunglei District of Mizoram

2021 ◽  
Vol 9 (1) ◽  
pp. 94-100
Author(s):  
Lal lawmzuala ◽  
◽  
Zaithanzauva Pachuau ◽  
Lalrinthara Pachuau ◽  
◽  
...  
Keyword(s):  
Power Density ◽  
Average Power ◽  
Base Station ◽  
National Standards ◽  
Base Stations ◽  
Health Symptoms ◽  
First Time ◽  
Power Densities ◽  
Specific Health ◽  
Mobile Base

In this paper we present the study of how Radio Frequency (RF) Radiations emitted by mobile base stations effects human health on thirteen different non-specific health symptoms residing in the vicinity of base stations. The survey was conducted on people living within and beyond 50m from mobile base station in Lunglei district, Mizoram for the first time since mobile tower was erected in 2008. Power density from mobile towers have also been measured within and outside 50m from the station for GSM900 and GSM1800 in the same locality. The measured average power densities have been compared with standard limits given by various scientific bodies like International Commission on Non-Ionizing Radiation Protection (ICNIRP,1998), Bioinitiative Report (2012), Salzburg Resolution (2000) and current Indian National Standards. It has been found that the measured power density were well below the recommended limit given by ICNIRP,1998 and the Indian standard (2013) in all the selected sites of study, whereas in four localities the average power density was found to be higher than the recommended limits of Bioinitiative Report,2012 and Salzburg Resolution. Questionnaire survey was also conducted on different health symptoms faced by the inhabitants close to the base stations. The results were statistically analysed based on exposure and sex. From the correlation studies, it has been found that more is the power density more is the number of significant health complaints and, also females were found to be more effected than males.

scholarly journals Enhanced Power Extraction with Sediment Microbial Fuel Cells by Anode Alternation

Fuels ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 168-178
Author(s):  
Marzia Quaglio ◽  
Daniyal Ahmed ◽  
Giulia Massaglia ◽  
Adriano Sacco ◽  
Valentina Margaria ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Energy Harvesting ◽  
Power Density ◽  
Microbial Fuel Cells ◽  
Average Power ◽  
Power Extraction ◽  
Harvesting Technique ◽  
Harvesting Method ◽  
Energy Harvesting Devices ◽  
Efficient Power

Sediment microbial fuel cells (SMFCs) are energy harvesting devices where the anode is buried inside marine sediment, while the cathode stays in an aerobic environment on the surface of the water. To apply this SCMFC as a power source, it is crucial to have an efficient power management system, leading to development of an effective energy harvesting technique suitable for such biological devices. In this work, we demonstrate an effective method to improve power extraction with SMFCs based on anodes alternation. We have altered the setup of a traditional SMFC to include two anodes working with the same cathode. This setup is compared with a traditional setup (control) and a setup that undergoes intermittent energy harvesting, establishing the improvement of energy collection using the anodes alternation technique. Control SMFC produced an average power density of 6.3 mW/m2 and SMFC operating intermittently produced 8.1 mW/m2. On the other hand, SMFC operating using the anodes alternation technique produced an average power density of 23.5 mW/m2. These results indicate the utility of the proposed anodes alternation method over both the control and intermittent energy harvesting techniques. The Anode Alternation can also be viewed as an advancement of the intermittent energy harvesting method.

scholarly journals Near-field thermophotovoltaics for efficient heat to electricity conversion at high power density

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Rohith Mittapally ◽  
Byungjun Lee ◽  
Linxiao Zhu ◽  
Amin Reihani ◽  
Ju Won Lim ◽  
...  
Keyword(s):  
Power Density ◽  
High Power ◽  
High Efficiency ◽  
Near Field ◽  
Electrical Power ◽  
Photovoltaic Cells ◽  
High Power Density ◽  
Pv Cell ◽  
Electrical Power Output ◽  
Power Densities

AbstractThermophotovoltaic approaches that take advantage of near-field evanescent modes are being actively explored due to their potential for high-power density and high-efficiency energy conversion. However, progress towards functional near-field thermophotovoltaic devices has been limited by challenges in creating thermally robust planar emitters and photovoltaic cells designed for near-field thermal radiation. Here, we demonstrate record power densities of ~5 kW/m2 at an efficiency of 6.8%, where the efficiency of the system is defined as the ratio of the electrical power output of the PV cell to the radiative heat transfer from the emitter to the PV cell. This was accomplished by developing novel emitter devices that can sustain temperatures as high as 1270 K and positioning them into the near-field (<100 nm) of custom-fabricated InGaAs-based thin film photovoltaic cells. In addition to demonstrating efficient heat-to-electricity conversion at high power density, we report the performance of thermophotovoltaic devices across a range of emitter temperatures (~800 K–1270 K) and gap sizes (70 nm–7 µm). The methods and insights achieved in this work represent a critical step towards understanding the fundamental principles of harvesting thermal energy in the near-field.

scholarly journals Double-Deck Metal Solenoids 3D Integrated in Silicon Wafer for Kinetic Energy Harvester

Micromachines ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 74
Author(s):  
Nianying Wang ◽  
Ruofeng Han ◽  
Changnan Chen ◽  
Jiebin Gu ◽  
Xinxin Li
Keyword(s):  
Kinetic Energy ◽  
Power Density ◽  
Energy Harvester ◽  
High Efficiency ◽  
Vibrational Energy ◽  
Average Power ◽  
Wafer Level ◽  
Peak Voltage ◽  
Silicon Mold ◽  
Casting Technique

A silicon-chip based double-deck three-dimensional (3D) solenoidal electromagnetic (EM) kinetic energy harvester is developed to convert low-frequency (<100 Hz) vibrational energy into electricity with high efficiency. With wafer-level micro electro mechanical systems (MEMS) fabrication to form a metal casting mold and the following casting technique to rapidly (within minutes) fill molten ZnAl alloy into the pre-micromachined silicon mold, the 300-turn solenoid coils (150 turns for either inner solenoid or outer solenoid) are fabricated in silicon wafers for saw dicing into chips. A cylindrical permanent magnet is inserted into a pre-etched channel for sliding upon external vibration, which is surrounded by the solenoids. The size of the harvester chip is as small as 10.58 mm × 2.06 mm × 2.55 mm. The internal resistance of the solenoids is about 17.9 Ω. The maximum peak-to-peak voltage and average power output are measured as 120.4 mV and 43.7 μW. The EM energy harvester shows great improvement in power density, which is 786 μW/cm3 and the normalized power density is 98.3 μW/cm3/g. The EM energy harvester is verified by experiment to be able to generate electricity through various human body movements of walking, running and jumping. The wafer-level fabricated chip-style solenoidal EM harvesters are advantageous in uniform performance, small size and volume applications.

scholarly journals Power Density Improvement of Piezoelectric Energy Harvesters via a Novel Hybridization Scheme with Electromagnetic Transduction

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 803
Author(s):  
Zhongjie Li ◽  
Chuanfu Xin ◽  
Yan Peng ◽  
Min Wang ◽  
Jun Luo ◽  
...  
Keyword(s):  
Power Density ◽  
Output Power ◽  
Energy Harvester ◽  
Hybrid Energy ◽  
Energy Harvesters ◽  
Piezoelectric Patch ◽  
Piezoelectric Energy ◽  
Electromagnetic Transduction ◽  
Self Powered ◽  
Power Densities

A novel hybridization scheme is proposed with electromagnetic transduction to improve the power density of piezoelectric energy harvester (PEH) in this paper. Based on the basic cantilever piezoelectric energy harvester (BC-PEH) composed of a mass block, a piezoelectric patch, and a cantilever beam, we replaced the mass block by a magnet array and added a coil array to form the hybrid energy harvester. To enhance the output power of the electromagnetic energy harvester (EMEH), we utilized an alternating magnet array. Then, to compare the power density of the hybrid harvester and BC-PEH, the experiments of output power were conducted. According to the experimental results, the power densities of the hybrid harvester and BC-PEH are, respectively, 3.53 mW/cm3 and 5.14 μW/cm3 under the conditions of 18.6 Hz and 0.3 g. Therefore, the power density of the hybrid harvester is 686 times as high as that of the BC-PEH, which verified the power density improvement of PEH via a hybridization scheme with EMEH. Additionally, the hybrid harvester exhibits better performance for charging capacitors, such as charging a 2.2 mF capacitor to 8 V within 17 s. It is of great significance to further develop self-powered devices.

Giant power density produced by PIN–PMN–PT ferroelectric single crystals due to a pressure induced polar-to-nonpolar phase transformation

2021 ◽  
Author(s):  
Sergey I. Shkuratov ◽  
Jason Baird ◽  
Vladimir G. Antipov ◽  
Christopher S. Lynch ◽  
Shujun Zhang ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Energy Storage ◽  
Single Crystals ◽  
Power Density ◽  
Ferroelectric Materials ◽  
Power Supplies ◽  
Energy Storage Devices ◽  
Storage Devices ◽  
New Generation ◽  
Power Densities

The search for ferroelectric materials capable of producing high electric charge and power densities is important for developing a new generation of ultrahigh-power-density ferroelectric energy storage devices and autonomous megawatt power supplies.

scholarly journals Delta and Theta waves in Super Consciousness Meditation.

2020 ◽  
Author(s):  
Anil Kumar Bheemaiah
Keyword(s):  
Average Power ◽  
Spectral Densities ◽  
Theta Wave ◽  
Convolutional Networks ◽  
Theta Waves ◽  
Power Spectral ◽  
Power Spectral Densities ◽  
Lyapunov Coefficient ◽  
Fmri Time Series ◽  
Power Densities

Study on Kundalini Meditation of Super-conscious Meditation of the Himalayan Tradition and Sahaja Meditation, to determine the average power spectral densities and power ratios of TP9, AF7, AF8, and TP10, electrodes and two ear electrodes on a Muse Headset.These parameters are used to create quantitative criteria to indicate degree of meditation and to create a trigger for bird chirp events.We find an increase in Delta and Theta wave power densities, in the deep meditation state as compared to the initiation and restful states. keywords: Kundalini, super consciousness, neurosky, muse, chakra based meditation, alpha to beta ratio, delta to beta ratio, power spectral densities, differential power spectral densities, fMRi, time series, iD convolutional networks. Lyapunov coefficient

scholarly journals Fast Sheath-driven Electrothermal Artificial Muscles with High Power Densities

2021 ◽  
Author(s):  
Xinghao Hu ◽  
Jingjing Jia ◽  
Yingming Wang ◽  
Xintian Tang ◽  
Shaoli Fang ◽  
...  
Keyword(s):  
Direct Contact ◽  
High Performance ◽  
Large Diameter ◽  
Average Power ◽  
Artificial Muscles ◽  
Slow Cooling ◽  
Prior Art ◽  
Performance Results ◽  
Power Densities ◽  
Sheath Material

Abstract Electrothermal carbon nanotube (CNT) yarn muscles can provide large strokes during heating-cooling cycles. However, the slow cooling rate of thermal muscles limit their applications, since large diameter prior-art thermal muscles cannot be rapidly cycled. We here report an ultrafast thermally powered sheath-driven yarn muscle that uses a hybrid CNT sheath and an inexpensive polymer core. Our coiled muscle contracts 14.3% at 1 Hz and 7.3% at 8 Hz in air when powered by a square-wave electrical voltage input. The 70-mm-diameter actuated muscle cools in air to 16℃ from 150℃ within 0.5 s, compared with 6 s for a 65-mm-diameter sheath-run muscle that uses an electrothermally heated CNT core and 9 s for a 78-mm-diameter muscle that uses the sheath material for the entire muscle. An average power density of 12 kW/kg was obtained for a sheath-driven muscle, which is 42 times that for human skeletal muscle. This high performance results since the heating that drives fast actuation cycles is largely restricted to the muscle sheath, and this sheath is in direct contact with ambient temperature air.

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