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Energy harvester

David M Jonas
Femtosecond two-dimensional (2D) Fourier transform spectroscopy generates and probes several types of coherence that characterize the couplings between vibrational and electronic motions. These couplings have been studied in molecules with Jahn-Teller conical intersections, pseudo-Jahn-Teller funnels, dimers, molecular aggregates, photosynthetic light harvesting complexes, and photosynthetic reaction centers. All have closely related Hamiltonians and at least two types of vibrations, including one that is decoupled from the electronic dynamics and one that is nonadiabatically coupled...
April 20, 2018: Annual Review of Physical Chemistry
Vellimalai Punitharasu, Munavvar Fairoos Mele Kavungathodi, Jayaraj Nithyanandhan
To synergize both steric and electronic factors in designing the dyes for dye-sensitized solar cells (DSSCs), a series of cis-configured unsymmetrical squaraine dyes P11-15 with suitably functionalized alkyl groups and electron withdrawing group containing squaric acid unit were synthesized, respectively. These dyes capture the importance of (i) the effect and position of branched alkyl groups, (ii) mono- and di-anchoring groups containing dyes and (iii) further appending alkyl groups through the cyanoester vinyl unit on the central squaric acid units of D-A-D based cis-configured squaraine dyes...
April 20, 2018: ACS Applied Materials & Interfaces
M H Ansari, M Amin Karami
A miniature nonlinear piezoelectric energy harvester is developed to power state of the art leadless cardiac pacemakers from cardiac motions. The energy harvester is integrated in the leadless pacemaker and is connected to the myocardium. The energy harvester converts myocardial motions to electricity to power leadless pacemakers. The energy is stored in a battery or supercapacitor and is used for pacing. The device is composed of a bimorph piezoelectric beam confined in a gray iron frame. The system is assembled at high temperature and operated at the body temperature...
February 2018: Journal of Intelligent Material Systems and Structures
M H Ansari, M Amin Karami
This paper studies the fabrication and testing of a magnet free piezoelectric energy harvester (EH) for powering biomedical devices and sensors inside the body. The design for the EH is a fan-folded structure consisting of bimorph piezoelectric beams folding on top of each other. An actual size experimental prototype is fabricated to verify the developed analytical models. The model is verified by matching the analytical results of the tip acceleration frequency response functions (FRF) and voltage FRF with the experimental results...
June 2017: Smart Materials & Structures
Yueyong Xin, Yang Shi, Tongxin Niu, Qingqiang Wang, Wanqiang Niu, Xiaojun Huang, Wei Ding, Lei Yang, Robert E Blankenship, Xiaoling Xu, Fei Sun
Photosynthetic prokaryotes evolved diverse light-harvesting (LH) antennas to absorb sunlight and transfer energy to reaction centers (RC). The filamentous anoxygenic phototrophs (FAPs) are important early branching photosynthetic bacteria in understanding the origin and evolution of photosynthesis. How their photosynthetic machinery assembles for efficient energy transfer is yet to be elucidated. Here, we report the 4.1 Å structure of photosynthetic core complex from Roseiflexus castenholzii by cryo-electron microscopy...
April 19, 2018: Nature Communications
Francesco Dell' Anna, Tao Dong, Ping Li, Yumei Wen, Mehdi Azadmehr, Mario Casu, Yngvar Berg
This paper presents a novel threshold-compensation technique for multi-stage voltage multipliers employed in low power applications such as passive and autonomous wireless sensing nodes (WSNs) powered by energy harvesters. The proposed threshold-reduction technique enables a topological design methodology which, through an optimum control of the trade-off among transistor conductivity and leakage losses, is aimed at maximizing the voltage conversion efficiency (VCE) for a given ac input signal and physical chip area occupation...
April 17, 2018: Sensors
Manuel Pérez-Ruiz, Pilar Rallo, M Rocío Jiménez, Miguel Garrido-Izard, M Paz Suárez, Laura Casanova, Constantino Valero, Jorge Martínez-Guanter, Ana Morales-Sillero
New super-high-density (SHD) olive orchards designed for mechanical harvesting using over-the-row harvesters are becoming increasingly common around the world. Some studies regarding olive SHD harvesting have focused on the effective removal of the olive fruits; however, the energy applied to the canopy by the harvesting machine that can result in fruit damage, structural damage or extra stress on the trees has been little studied. Using conventional analyses, this study investigates the effects of different nominal speeds and beating frequencies on the removal efficiency and the potential for fruit damage, and it uses remote sensing to determine changes in the plant structures of two varieties of olive trees (‘Manzanilla Cacereña’ and ‘Manzanilla de Sevilla’) planted in SHD orchards harvested by an over-the-row harvester...
April 17, 2018: Sensors
Peter Bateson, Jack E H Fleet, Anthony S Riseley, Elena Janeva, Anastasia S Marcella, Chiara Farinea, Maria Kuptsova, Núria Conde Pueyo, Christopher J Howe, Paolo Bombelli, Brenda M Parker
Photobioelectrochemical systems are an emerging possibility for renewable energy. By exploiting photosynthesis, they transform the energy of light into electricity. This study evaluates a simple, scalable bioelectrochemical system built from recycled plastic bottles, equipped with an anode made from recycled aluminum, and operated with the green alga Chlorella sorokiniana . We tested whether such a system, referred to as a bio-bottle-voltaic (BBV) device, could operate outdoors for a prolonged time period of 35 days...
April 17, 2018: Biology
Igor Alexander Harsch, Peter Christopher Konturek
The investigation of the human microbiome is the most rapidly expanding field in biomedicine. Early studies were undertaken to better understand the role of microbiota in carbohydrate digestion and utilization. These processes include polysaccharide degradation, glycan transport, glycolysis, and short-chain fatty acid production. Recent research has demonstrated that the intricate axis between gut microbiota and the host metabolism is much more complex. Gut microbiota—depending on their composition—have disease-promoting effects but can also possess protective properties...
April 17, 2018: Medical Sciences: Open Access Journal
Soonyong Song, Donghun Lee, Ingook Jang, Jinchul Choi, Youngsung Son
Energy harvester-integrated wireless devices are attractive for generating semi-permanent power from wasted energy in industrial environments. The energy-harvesting wireless devices may have difficulty in their communication with access points due to insufficient power supply for beacon recognition during network initialization. In this manuscript, we propose a novel method of beacon recognition based on wake-up control to reduce instantaneous power consumption in the initialization procedure. The proposed method applies a moving window for the periodic wake-up of the wireless devices...
April 17, 2018: Sensors
Sanwasan Yodkhum, Sate Sampattagul, Shabbir H Gheewala
Rice cultivation and energy use for rice production can produce the environmental impacts, especially related to greenhouse gas (GHG) emissions. Also, rice straw open burning by farmers generally practiced after harvesting stage in Thailand for removing the residues in the rice field is associated with emissions of air pollutants, especially particulate matter formation that affects human health and global climate. This study assessed the environmental burdens, consisting of GHG emissions, energy use, and particulate matter formation (PM10), from rice cultivation in Thailand by life cycle assessment (LCA) and compared the environmental burdens of rice straw management scenarios: open burning, incorporation into soil, and direct combustion for electricity generation...
April 17, 2018: Environmental Science and Pollution Research International
Jialong Duan, Yuanyuan Zhao, Benlin He, Qunwei Tang
Perovskite solar cells with cost-effectiveness, high power conversion efficiency, and improved stability are promising solutions to the energy crisis and environmental pollution. However, a wide-bandgap inorganic-semiconductor electron-transporting layer such as TiO2 can harvest ultraviolet light to photodegrade perovskite halides, and the high cost of a state-of-the-art hole-transporting layer is an economic burden for commercialization. Here, the building of a simplified cesium lead bromide (CsPbBr3 ) perovskite solar cell with fluorine-doped tin oxide (FTO)/CsPbBr3 /carbon architecture by a multistep solution-processed deposition technology is demonstrated, achieving an efficiency as high as 4...
April 17, 2018: Small
Meng-Jia Sun, Yu-Wu Zhong, Jiannian Yao
Thermal-responsive phosphorescent nanotubes have been fabricated from the co-assembly of two neutral iridium complexes, which behave as the antenna chromophores and energy acceptors respectively in these highly-ordered crystalline superstructures. By tuning the acceptor doping ratio in a range of 0 - 0.5%, these tubes display color-tunable phosphorescence from green to red at room temperature, attributed to the highly efficient light-harvesting and energy transfer in these materials. For the same reason, the acceptor emission in the nanotubes is amplified more than 800 times with respect to its pure nonemissive solid sample...
April 17, 2018: Angewandte Chemie
Shishir Pandya, Joshua Wilbur, Jieun Kim, Ran Gao, Arvind Dasgupta, Chris Dames, Lane W Martin
The need for efficient energy utilization is driving research into ways to harvest ubiquitous waste heat. Here, we explore pyroelectric energy conversion from low-grade thermal sources that exploits strong field- and temperature-induced polarization susceptibilities in the relaxor ferroelectric 0.68Pb(Mg1/3 Nb2/3 )O3 -0.32PbTiO3 . Electric-field-driven enhancement of the pyroelectric response (as large as -550 μC m-2  K-1 ) and suppression of the dielectric response (by 72%) yield substantial figures of merit for pyroelectric energy conversion...
April 16, 2018: Nature Materials
Ryo Nagao, Yoshifumi Ueno, Makio Yokono, Jian-Ren Shen, Seiji Akimoto
Maintenance of energy balance under changeable light conditions is an essential function of photosynthetic organisms to achieve efficient photochemical reactions. Among the photosynthetic organisms, diatoms possess light-harvesting fucoxanthin chlorophyll (Chl) a/c-binding protein (FCP) as peripheral antennas. However, how diatoms regulate excitation energy distribution between FCP and the two photosystem cores during light adaptation is poorly understood. In this study, we examined spectroscopic properties of a marine diatom Chaetoceros gracilis adapted in the dark and at photosynthetic photon flux density at 30 and 300 μmol photons m-2  s-1 ...
April 13, 2018: Biochimica et Biophysica Acta
Alba du Toit, Maryna de Wit, Arno Hugo
Mucilage extracted from cactus pear cladodes is a hydrocolloid gum. It is a novel, natural, low-kilojoule, cost-effective texture-modifying ingredient in functional food products. Yet, the cultivar with the most optimal nutrient content and the preferred harvest times are as yet unknown. For this reason, mucilage from three Opuntia ficus-indica (Algerian, Morado and Gymno-Carpo) and one Opuntia robusta (Robusta) cultivar were investigated to determine their nutrient content over six months. Nutrients that contribute energy (10...
April 16, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Haiwu Zheng, Yunlong Zi, Xu He, Hengyu Guo, Ying-Chih Lai, Jie Wang, Steven L Zhang, Changsheng Wu, Gang Cheng, Zhong Lin Wang
Harvesting energy available from ambient environment is highly desirable for powering personal electronics and health applications. Due to natural process and human activities, steam can be produced by boilers, human perspiration and the wind exists ubiquitously. In the outdoor environment, these two phenomena usually exist at the same place, which contain heat and mechanical energies simultaneously. However, previous studies have isolated them as separate sources of energy to harvest and hence failed to utilize them effectively...
April 16, 2018: ACS Applied Materials & Interfaces
Vangelis Daskalakis
The assembly and disassembly of protein complexes within cells are crucial life-sustaining processes. In photosystem II (PSII) of higher plants, there is a delicate yet obscure balance between light harvesting and photo-protection under fluctuating light conditions, that involves protein-protein complexes. Recent breakthroughs in molecular dynamics (MD) simulations are combined with new approaches herein to provide structural and energetic insight into such a complex between the CP29 minor antenna and the PSII subunit S (PsbS)...
April 16, 2018: Physical Chemistry Chemical Physics: PCCP
Ruijie Qi, Jinhui Nie, Mingyang Liu, Mengyang Xia, Xianmao Lu
Stretchable energy storage devices are of great importance for the viable applications of wearable/stretchable electronics. Studies on stretchable energy storage devices, especially supercapacitors (SCs), have shown encouraging progress. However, challenges still remain in the pursuit of high specific capacitances and facile fabrication methods. Herein, we report a modular materials fabrication and assembly process for stretchable SCs. With a V2O5/PEDOT composite as the active material, the resulting stretchable SCs exhibited high areal specific capacitances up to 240 mF cm-2 and good capacitance retention at a strain of 50%...
April 16, 2018: Nanoscale
Huijun Wu, Shun Wang, Liangmin Gao, Ling Zhang, Zengwei Yuan, Tingyu Fan, Kaiping Wei, Li Huang
Nitrogen (N) and phosphorus (P) play a critical role in agricultural production and cause many environmental disturbances. By combing life cycle assessment (LCA) method with the mass balance principle of substance flow analysis (SFA), this study establishes a nutrient-derived environmental impact assessment (NEIA) model to analyze the environmental impacts caused by nutrient-containing substances of agricultural production in China during 1978-2015. The agricultural production system is composed of crop farming and livestock breeding, and the environmental impacts include energy consumption, global warming, acidification, and eutrophication...
April 12, 2018: Journal of Environmental Management
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