Discover insights from thousands of peer-reviewed papers on microbial electrochemical systems
T. Dudding, C. Vaizey
Colorectal Disease · 2010
Abstract Objective In patients undergoing sacral nerve stimulation (SNS), a temporary percutaneous stimulation wire is often used to assess the clinical response to therapy prior to chronic stimulation. The aim of this study was to evaluate the incidence of bacterial colonization of screening wires and risk of clinical infection in patients undergoing prolonged temporary SNS screening. Method Data were collected prospectively on a consecutive series of patients undergoing temporary SNS for bowel dysfunction. Procedures were performed using a standardized percutaneous technique with a single shot of either co‐amoxyclav 1.2 g or cefuroxime 1.5 g given intravenously on induction. Adherent polyurethane dressings were applied to secure the wire. At the end of the screening period the wire and dressings were removed, the skin entry site was cleaned using an alcohol wipe and the wire removed via an aseptic technique. The distal tip of the wire was then cut and sent for culture. Results Thirteen wires were removed at a median of 21 (range 16–29) days following insertion. There were no signs of local or systemic infection. Seven of the thirteen wires (54%) were found to have deep bacterial colonization. The commonest organisms isolated were staphylococcus species. There was no correlation between the length of time the lead had been implanted and the incidence of bacterial colonization. Conclusion Bacterial colonization of the temporary stimulation wire is common but appears to be associated with a low risk of clinical infection. A single peri‐operative dose of antibiotics does not appear to prevent colonization.
Shumin Liu, Jia Chen, Jinpeng Sun
International Journal of Biology and Life Sciences · 2023
Using the natural nanomesh structure of bacterial cellulose (BC), the good conductivity of multi-walled carbon nanotubes (MWCNTs) and the good electrocatalytic activity of nano platinum (PtNPs), a three-way porous conductive hydrogel of PtNPs and BC was designed. The infiltrating and doping of MWCNTs on BC thin films was realized by ultrasonic assisted electrophoretic deposition process, which ensured the dual characteristics of ionic and electronic conduction of electrode films. The adsorption capacity of BC for chloroplatinic acid and the strong reductivity of sodium borohydride were also used to realize the high-load PtNPs recombination on MWCNTs/BC porous layered conductive hydrogel electrode films. By testing the electrochemical performance of PtNPs/MWCNTs/BC conductive hydrogel electrode film and characterization of microstructure, the electrode film not only has high electroactive area, low surface charge transfer resistance and good diffusion permeability and other electrochemical characteristics, but also shows high catalytic activity for glucose in PBS solution. The most important finding is that the electrode film can selectively catalyze glucose in oxygen-rich PBS solution. The porous layered structure of PtNPs/MWCNTs/BC electrode membrane and the high load dispersion of PtNPs are the reasons for the selective catalytic ability of PtNPs/MWCNTs/BC conductive hydrogel electrode membrane, which can be used for the implanted surface glucose fuel cell.
Hans‐Peter Schär, Oreste Ghisalba
Biotechnology and Bioengineering · 1985
Abstract A biosensor consisting of physically entrapped monomethyl sulfate (methyl sulfate) degrading bacterium, Hyphomicrobium MS 219 , and a combined glass electrode has been developed for the determination of methyl sulfate. The response of the bacterial electrode is linear between 2.5 × 10 −2 M and 6.3 × 10 −1 M methyl sulfate with an effective response to concentrations as low as 10 −3 M and as high as 1 M methyl sulfate. The probe has an average slope of 8 mV per concentration decade over the linear range. Response times vary from 5 min in the linear range to 30 min at the detection limit. The sensor has a lifetime of at least 1 week and shows high selectivity to methyl sulfate in the absence of other growth substrates.
H.-E. Jacob
Pathobiology · 1970
In bacterial cultures and buffer solutions the redoxpotential values depend on the condition of the electrode surface. This is shown by comparison of various pretreatments of the electrode. In order to obtain a fast response of the redoxpotential as a function of changes in oxygen pressure and to measure redox’ potential-values accurately, mechanical cleaning and polishing of the platinum electrode is recommended.
A. L. Yarin
Applied Physics Letters · 2007
In this letter, the origin of a force resulting in steady-state propagation of a spherical electrode in a leaky dielectric is explained and the force is calculated. The phenomenon of self-propagation begins from a perturbation in any direction resulting in the electrode motion in that direction. After that, the process sustains itself and a macroscopic electrode moves in the direction of the initial perturbation with a constant velocity U proportional to the potential difference ΔV applied to the system. Microscopic electrodes and bacterial flagellar motors should move with a velocity U∼(ΔV)2. The predicted velocities agree fairly well with the experimental data.
Chinnatad Sinprasertchok, Nuwong Chollacoop, Sumittra Charojrochkul et al.
Key Engineering Materials · 2017
Microbial extracellular electron transfer is a significant process in a microbial fuel cell (MFC). Owing to many potential losses in the electron transfer from microorganism to an electrode, a promotion of microbial attachment to electrode should be a productive solution to this difficulty of MFC. We also introduced here a prior colonization of microbes on electrode instead of a conventional immobilization which entirely occurred in a MFC reactor to expedite an attachment of microorganisms on the electrode surface. Coconut shell-based granular activated carbons (CGACs) used as one of the electrodes in the upflow bio-filter circuit microbial fuel cell were immersed in Lysogeny broth (LB) at pH 7 before an inoculation of anaerobic consortium from a wastewater treatment plant was performed. The immobilization was proceeded in an Erlenmeyer flask at 30°C with a shaking speed of 100 rpm throughout an experiment. CGACs taken from a collection of flasks were examined a surface with scanning electron microscopy (SEM). On the 3 rd day of immobilization, SEM images showed that a colonization was seen obviously in large pores on CGAC surface. There were quite plentiful possessions on a rough surface while smooth surface not supporting well at the beginning got worse in attraction of bacteria on day 9 of immobilization. An addition of fresh LB into immobilization solution was conducted to improve the microbial attachment to smooth surface of CGAC. At 9 days after inoculation, the consequence of fresh medium filling did obviously raise the number of bacteria on the plain surface as opposed to earlier experiment.
Leonard M. Tender
MRS Bulletin · 2011
Abstract
Michael Chen, Neha Mehta, Benjamin D. Kocar
ChemRxiv · 2020
Semi-conducting Fe oxide minerals, such as hematite, are well known to influence the fate of contaminants and nutrients in many environmental settings and influence microbial growth under suboxic to anoxic conditions through a myriad of different processes. Recent studies of Fe oxide reduction by Fe(II) have demonstrated that reduction of Fe at one surface can result in the release of Fe(II) different one. Termed Fe(II) catalyzed recrystallization, this phenomena is attributed to conduction of additional electrons through the mineral structure from the point of contact to another which occurs because of the minerals’ semi-conductivity. While it is well understood that Fe(II) plays a central role in redox cycling of elements, the environmental implications of Fe(II) catalyzed recrystallization need to be further explored. Here, we provide evidence that the Fe mineral conductivity underpinning Fe(II) catalyzed recrystallization can couple the reduction of Cr, a priority metal contaminant, with an electron source that is cannot directly affect Cr. This is shown for both an abiotic electron source, a potentiostat, as well as the metal reducing bacteria Shewanella Putrefaciens. The implications of this work show that semiconductive minerals may be links in subsurface electrical networks that physically distribute redox chemistry and suggests novel methods for remediating Cr contamination in groundwater.
Stanley E. Manahan
Applied Microbiology · 1969
A nitrate ion-selective electrode has been used to follow the kinetics of the reduction of nitrate by a bacillus isolated from the rumen of a sheep. The electrode system and the microbial culture were found to be quite compatible, although the formation of nitrite limits the utility and precision of the measurement. The formation of nitrite was followed simultaneously by a colorimetric method. Nitrate was converted quantitatively to nitrite. The rate of the reaction was found to increase to a plateau value, then drop abruptly when the nitrate was exhausted.
Karol Lang
Bio-Algorithms and Med-Systems · 2024
<b>Objective:</b> The in-vivo therapy guidance by imaging and dosimetry of proton irradiations, generically known as proton range verification, are some of the most underinvested aspects of radiation oncology. They trail behind other advances in radiation therapy due to the scarcity of sensitive instruments compounded by the lack of treatment protocols for precision monitoring of effects of beam radiation. This is despite that such measurements may dramatically enhance the treatment accuracy and lower the postradiation toxicity, thus improving the entire outcome of cancer therapy. <br><b>Methods:</b> In this contribution, we focus on the motivation of designing and building of an in-beam time-of-flight (ToF) positron-emission-tomography (PET) scanner with the depth-of-interaction (DoI) capability for high sensitivity and improved fidelity of imaging. A scanner could be augmented with a tungsten collimator that would enable prompt-gamma imaging (PGI) via single-photon emission computed tomography (SPECT) technique. <br><b>Results:</b> We present selected results of our pre-clinical experiments with a FLASH proton beam and discuss other related ideas towards improving and expanding the use of PET/PGI/SPECT detectors for proton therapy. A scanner provides an access to data during the spill and past the spill permitting to capture the beam interaction and kinetic monitoring of its effect thus allowing a thorough assessment of each irradiation.<br><b>Conclusions:</b> A novel scanner for multiple modalities can substantially improve the treatment precision of proton therapy leading to less toxic outcome of irradiations. Using it in the FLASH modality would additionally expand the patient reach of proton therapy.
Sergey Kukushkin, Dariko Balakhanov, Yury Zhurov
BIO Web of Conferences · 2024
These days the economic system of any scale faces a challenge not only to best meet the needs of consumers, but also to ensure their comfortable living conditions (especially agricultural), that is, preserve the environment and use natural resources wisely. Power generation enterprises make a significant contribution to the violation of the environmental situation. This is partly due to the alienation of territories that could be used for other human activities, as well as significant emissions into the atmosphere. A power generation enterprise, compared with organizations of other types of activity, is characterized by the method of generating electricity which implies not the impact on the material and raw materials and the production of economic benefits, but the conversion of natural energy into electrical energy. These models are of a general abstract nature and are more applicable to organizations producing tangible economic benefits, rather than the generation of electrical energy, which is the key economic benefit, though, conventionally tangible one. Existing microeconomic models do not show specifics of their functioning – the scale of the enterprise and the conditions for profit maximization. The economic models of a power generation enterprise, the specifics of its functioning and profit-making are presented in the article.
Chris Vermillion
Volume 3: Nonlinear Estimation and Control; Optimization and Optimal Control; Piezoelectric Actuation and Nanoscale Control; Robotics and Manipulators; Sensing; System Identification (Estimation for Automotive Applications, Modeling, Therapeutic Control in Bio-Systems); Variable Structure/Sliding-Mode Control; Vehicles and Human Robotics; Vehicle Dynamics and Control; Vehicle Path Planning and Collision Avoidance; Vibrational and Mechanical Systems; Wind Energy Systems and Control · 2013
This paper presents a control strategy that combines altitude and crosswind motion control for tethered wind energy systems with airborne turbines and generators. The proposed algorithm adjusts altitude and induces an appropriate level of crosswind motion to present the system with an apparent wind speed that most closely meets, but does not exceed, the rated wind speed of the on-board turbine(s), thereby tracking the turbine’s optimal power point. The adjustment of both altitude and motion control, along with the reduction in crosswind motion and altitude when the rated wind speed is exceeded, differentiates the proposed control architecture from other strategies proposed in the literature. Initial control laws and simulation results are presented for the Altaeros lighter-than-air wind energy system.
M. H. Ansari, Karthik Yerrapragada, M. Amin Karami
Volume 2: Modeling, Simulation and Control; Bio-Inspired Smart Materials and Systems; Energy Harvesting · 2016
When there is a two to one internal resonance ratio between the natural frequencies of the pitch motion and the roll motion of a ship, a nonlinear energy transfer occurs between the modes. If the ship is excited near the pitch natural frequency and at a large enough excitation amplitude, the pitch mode transfers energy to the roll mode. We use this interesting phenomenon to develop a wave power device for off-shore purposes. In this paper, we experimentally show that we can use a horizontal pendulum and use the quadratic nonlinear coupling between the pitch and the roll mode to get full rotation of the pendulum inside the ship. A rotating pendulum will generate orders of magnitude more power than a locally oscillating one when connected to a DC generator. This article measures the angle of the pendulum at the pitch frequency excitation of the ship to experimentally confirm the expected theoretical results on this phenomenon.
Mario L. Ferrari, Marco De Campo, Loredana Magistri
Volume 3: Coal, Biomass, and Alternative Fuels; Cycle Innovations; Electric Power; Industrial and Cogeneration; Organic Rankine Cycle Power Systems · 2018
This paper presents a steady-state model of an innovative turbocharged solid oxide fuel cell system fed by biofuel. The aim of this plant layout is the development of a reduced-cost solution, which involves the pressurization carried out with a mass production machine such as a turbocharger (instead of a microturbine). The turbocharger pressurizes the solid oxide fuel cell to increase the performance. Following the experimental results to choose the suitable machine and for validating the turbocharger model, this tool was implemented to model the whole plant. It was used to calculate the operational conditions and to define the coupling aspects between the turbocharger, the recuperator and the solid oxide fuel cell system (comprising a fuel cell stack, an air preheater, a reformer, an off-gas burner and an anodic ejector). The model permitted the component characterization and supported the design of an emulator test rig based on the coupling of a turbocharger and a pressure vessel. This facility was designed to conduct the experimental tests at system level on the matching between the machine and the fuel cell, especially for the dynamic and the control system aspects. To emulate the fuel cell, the rig was based on a specially designed pressure vessel equipped with a burner and inert ceramic materials. Moreover, the facility was designed to produce the turbine inlet conditions in terms of mass flow, temperature, pressure and gas composition (similitude conditions can be evaluated).
Mykola Vasylenko, Olha Baranova
Electronics and Control Systems · 2024
Alternative energy sources allows to replace traditional fossil fuels and firewood. However the most widely used wind and solar power plants can not provide constant power generation due to multiple factors that makes necessary to develop new types of power sources and to to improve efficiency of already existing ones. One of such energy sources are bio gas-fueled power plants which allow to combine the power generation and organic waste disposal functions. Efficiency and quality of bio gas production in such facilities can be significantly increased by using different catalysts such as biochar. A brief analysis of biochar production usage perspectives was held which showed that it can be used in different applications and can significantly increase efficiency of different technological processes. The influence of biochar on the biogas production processes was studied. The structure of bio gas-fueled heat and power plant with local bio gas generation was proposed.
Gustave Ronteix, Andrey Aristov, Valentin Bonnet et al.
bioRxiv (Cold Spring Harbor Laboratory) · 2022
Microscopy techniques and image segmentation algorithms have improved dramatically this decade, leading to an ever increasing amount of biological images and a greater reliance on imaging to investigate biological questions. This has created a need for methods to extract the relevant information on the behaviors of cells and their interactions, while reducing the amount of computing power required to organize this information. This task can be performed by using a network representation in which the cells and their properties are encoded in the nodes, while the neighborhood interactions are encoded by the links. Here, we introduce Griottes, an open-source tool to build the “network twin” of 2D and 3D tissues from segmented microscopy images. We show how the library can provide a wide range of biologically relevant metrics on individual cells and their neighborhoods, with the objective of providing multi-scale biological insights. The library’s capacities are demonstrated on different image and data types. This library is provided as an open-source tool that can be integrated into common image analysis workflows to increase their capacities.
J. Lv, Xin Zhang, Nana Li et al.
RSC Advances · 2015
Metal nanoparticles (MNPs) can be used as a kind of new photodynamic therapy (PDT) agent because singlet oxygen (1O2) can be generated through directly sensitizing MNPs. Gold nanorods, gold nanoshells and gold nanoechinus were confirmed to be efficient PDT agents in vivo. However, the major excitation spectra of 1O2 from all of them are not in the optical biological window (650–900 nm). Herein, gold bipyramids (GBPs) with tunable absorption wavelength were prepared and used to explore 1O2 generation capability. 1O2 can be generated when GBPs were excited by continuous-wave light within a wide range of wavelengths (660–975 nm). The highest 1O2 generation capabilities were obtained when they were excited at the wavelength of the absorption peak, which was quite different from those of other gold nanomaterials. It was also found that 1O2 can be generated efficiently by a laser of very low power density (200 mW cm−2). The capability of GBPs for PDT has been demonstrated through the destruction of cancer cells. The synergistic effect of PDT and photothermal therapy for the destruction of cancer cells was also demonstrated.
Hanwen Liu, Yi Chen, ZiHang Zeng et al.
2023 International Joint Conference on Neural Networks (IJCNN) · 2023
Spiking Neural Networks (SNNs), known as the third generation of the neural network, are famous for their biological plausibility and brain-like characteristics. Recent efforts further demonstrate the potential of SNNs in high-speed inference by designing accelerators with the parallelism of temporal or spatial dimensions. However, with the limitation of hardware resources, the accelerator designs must utilize off-chip memory to store many intermediate data, which leads to both high power consumption and long latency. In this paper, we focus on the data flow between layers to improve arithmetic efficiency. Based on the spike discrete property, we design a convolution-pooling(CONVP) unit that fuses the processing of the convolutional layer and pooling layer to reduce latency and resource utilization. Furthermore, for the fully-connected layer, we apply intra-output parallelism and inter-output parallelism to accelerate network inference. We demonstrate the effectiveness of our proposed hardware architecture by implementing different SNN models with the different datasets on a Zynq XA7Z020 FPGA. The experiments show that our accelerator can achieve about x28 inference speed up with a competitive power compared with FPGA implementation on MNIST dataset and a x15 inference speed up with low power compared with ASIC design on DVSGesture dataset.
Jeechan Yoon, Bolim You, Yuna Kim et al.
ACS Applied Materials & Interfaces · 2023
While neuromorphic computing can define a new era for next-generation computing architecture, the introduction of an efficient synaptic transistor for neuromorphic edge computing still remains a challenge. Here, we envision an atomically thin 2D Te synaptic device capable of achieving a desirable neuromorphic edge computing design. The hydrothermally grown 2D Te nanosheet synaptic transistor apparently mimicked the biological synaptic nature, exhibiting 100 effective multilevel states, a low power consumption of ∼110 fJ, excellent linearity, and short-/long-term plasticity. Furthermore, the 2D Te synaptic device achieved reconfigurable MNIST recognition accuracy characteristics of 88.2%, even after harmful detergent environment infection. We believe that this work serves as a guide for developing futuristic neuromorphic edge computing.
Aldo Moscardini, S. Di Pietro, G. Signore et al.
Scientific Reports · 2020
Biological samples are mainly composed of elements with a low atomic number which show a relatively low electron scattering power. For Transmission Electron Microscopy analysis, biological samples are generally embedded in resins, which allow thin sectioning of the specimen. Embedding resins are also composed by light atoms, thus the contrast difference between the biological sample and the surrounding resin is minimal. Due to that reason in the last decades, several staining solutions and approaches, performed with heavy metal salts, have been developed with the purpose of enhancing both the intrinsic sample contrast and the differences between the sample and resin. The best staining was achieved with the uranyl acetate (UA) solution, which has been the election method for the study of morphology in biological samples. More recently several alternatives for UA have been proposed to get rid of its radiogenic issues, but to date none of these solutions has achieved efficiencies comparable to UA. In this work, we propose a different staining solution (X Solution or X SOL), characterized by lanthanide polyoxometalates (LnPOMs) as heavy atoms source, which could be used alternatively to UA in negative staining (NS), in en bloc staining, and post sectioning staining (PSS) of biological samples. Furthermore, we show an extensive chemical characterization of the LnPOM species present in the solution and the detailed work for its final formulation, which brought remarkable results, and even better performances than UA.
M. R. Edwards, J. Mikhailova
Scientific Reports · 2020
Ultrashort pulsed lasers provide uniquely detailed access to the ultrafast dynamics of physical, chemical, and biological systems, but only a handful of wavelengths are directly produced by solid-state lasers, necessitating efficient high-power frequency conversion. Relativistic plasma mirrors generate broadband power-law spectra, that may span the gap between petawatt-class infrared laser facilities and x-ray free-electron lasers; despite substantial theoretical work the ultimate efficiency of this relativistic high-order-harmonic generation remains unclear. We show that the coherent radiation emitted by plasma mirrors follows a power-law distribution of energy over frequency with an exponent that, even in the ultrarelativistic limit, strongly depends on the ratio of laser intensity to plasma density and exceeds the frequently quoted value of −8/3 over a wide range of parameters. The coherent synchrotron emission model, when adequately corrected for the finite width of emitting electron bunches, is not just valid for p-polarized light and thin foil targets, but generally describes relativistic harmonic generation, including at normal incidence and with finite-gradient plasmas. Our numerical results support the ω−4/3 scaling of the synchrotron emission model as a limiting efficiency of the process under most conditions. The highest frequencies that can be generated with this scaling are usually restricted by the width of the emitting electron bunch rather than the Lorentz factor of the fastest electrons. The theoretical scaling relations developed here suggest, for example, that with a 20-PW 800-nm driving laser, 1 TW/harmonic can be produced for 1-keV photons.
Ashutosh K. Giri, Sabha Raj Arya, Rakesh Maurya et al.
IET Renewable Power Generation · 2020
In this study, a control algorithm based on non‐linear adaptive second‐order Volterra filter (NLVF) is utilised to operate the voltage‐source converter (VSC). The main role of VSC is to supply compensating current to improve the power quality in wind‐based off‐grid distributed power generation system. This off‐grid system consists of three‐phase induction generator, VSC and non‐linear loads. The proposed control algorithm is adaptive as well as non‐linear in nature. The characteristic of Volterra series is exploited to generate the reference source current for VSC operation. The NLVF estimates the active and reactive weights of fundamental load current for reference current generation. It mitigates the power quality problems created by disturbances in non‐linear load or wind oscillations on off‐grid system. The solution of power quality problems such as the presence of harmonics in supply current, load unbalance and reactive power compensation is obtained. Nevertheless, voltage and frequency control are also achieved. The VSC is used as a shunt compensator in the system. The entire off‐grid system is designed and validated through the laboratory prototype development. The objective of the system is achieved and the steady state and dynamic performance is found satisfactory.
Jinn‐Chang Wu, Hurng‐Liahng Jou, Pei‐Hsuan Huang
IET Renewable Power Generation · 2020
This study proposes a seven‐level power conversion system for a solar power generation system. This seven‐level power conversion system consists of a DC–DC power converter and a cascade DC–AC inverter. The cascade DC–AC inverter comprises a full‐bridge inverter and a T‐type inverter. The T‐type inverter generates a three‐level quasi‐square‐wave voltage and the full‐bridge inverter provides a three‐level high‐frequency pulse voltage. The amplitude of the three‐level quasi‐square‐wave voltage is double that of the three‐level high‐frequency pulse voltage, so seven levels of AC voltage are synthesized. Only the full‐bridge inverter with lower DC bus voltage uses high‐frequency switching so switching losses are effectively reduced. The novelty of the proposed cascade DC–AC inverter is that the output power of T‐type inverter is controlled by regulating the DC bus voltage, so no real power is supplied from the full‐bridge inverter and an independent power source is not required to provide power to the full‐bridge inverter. The negative terminal voltage for solar cell array keeps almost constant to reduce the leakage current of proposed seven‐level power conversion system. A hardware prototype with a digital signal processor controller is developed to verify the performance of seven‐level power conversion system for a solar power generation system.
Kevin Kails, Quan Li, Markus Mueller
IET Renewable Power Generation · 2019
Stackable power generators enable very compact electric machines with high power density. How to identify an effective way of stacking is necessary and requires new knowledge for future guidance. In this study, both possibilities of stacking modules concentrically and axially are explored and compared. An axial flux generator based on the existing double claw pole design is used as a case study. The claw pole generator, which is modular and stackable, significantly benefits on‐site installation due to its flexible small modules that can be easily transported. This is particularly important to the installation of offshore wind turbines. Superconducting field windings are applied instead of copper in such power generators, which greatly increases their power density. In order to further increase their power density and reduce mass, the authors improved the modularity of 5 MW generators and stacked them in both ways. Results show that the power density versus mass as well as volume can be improved through stacking the modules both concentrically and axially, while the former approach is much more effective. Stacking two modules of 5 MW concentrically results in a 12.1 MW power generator with a more compact structure and higher power density than the original 10 MW generator.
Narayanan Shankar Ganesh, Gunasekaran Uma Maheswari, Tangellapalli Srinivas et al.
IET Renewable Power Generation · 2021
Abstract This paper introduces a novel power generation system using solar energy as a heat source. The proposed cycle incorporates heat sources from two solar collectors for the effective utilisation of heat energy. To aid the performance of the proposed system, the turbine flow rate is increased with the specific heater arrangements. Energy and exergy balances of the novel system were generated using Python software. The investigation of the present system was evaluated with high sink temperature. Turbine inlet concentration, turbine inlet pressure, HE 4 outlet temperature from the turbine, condenser concentration of ammonia, isentropic efficiency of the turbine and pressure ratio are the design variables considered for the exergy and thermoeconomic investigation. The energy and exergy analyses resulted in suitable design variables to optimise the performance. The optimum Kalina cycle efficiency, solar plant efficiency, exergy efficiency and network output were determined to be 18.51%, 8.28%, 34.51% and 295.24 kW, respectively. Among the components involved in the system, the mixers account for the highest exergy destruction followed by the turbine. The cycle performance can be improved by reducing the exergy destruction rate. The thermal efficiency is maximised by the turbine inlet pressure and temperature. Moreover, a higher relative cost difference has resulted in heat exchanger 5 and pump 2.
Peter Regner, Katharina Gruber, Sebastian Wehrle et al.
· 2021
&lt;p&gt;US Wind power generation has grown significantly over the last decades, driven by more and larger turbines being installed. However, less is known about how other factors affect the expansion of wind power. In this study, we use historical wind power generation time series, data on installed wind turbines and wind speed time series from the ERA5 data set to quantify driving factors of the growth of US wind power generation. By use of index-decomposition techniques and a regression analysis, we show how different factors affect the output of wind power generation in the US. These include changes in the number of installed turbines, average swept area, park efficiency, location choice, and hub height. Based on this, we discuss potential consequences for the future expansion of wind energy. As expected, the total rotor swept area is responsible for the largest part of the increase in generated power, due to a larger number of installed turbines and larger rotor sizes in particular. Unexpectedly, turbine efficiency slightly declined in the last decades. Wind speeds available to wind turbines have slightly increased. This is a result of larger hub heights, but also of new wind turbines being installed at windier locations.&lt;/p&gt;
Cheng Liu, Guowei Cai
IET Renewable Power Generation · 2019
With regards to the problems in which the power‐oscillation characteristics of power systems with high penetration of renewable power generation are complex and difficult to effectively analyse, a novel network virtual‐inertia method is proposed to evaluate the power oscillation in such systems. Firstly, the network virtual inertia is defined and developed. Secondly, the network virtual inertia is calculated and obtained based on the measurement information. Thirdly, the relationship between the network virtual inertia and generator inertia is constructed. Finally, the network virtual inertia of power systems with high penetration of renewable power generation is analysed. The evaluation method is effective and easy to implement. Simulations involving four‐generator two‐area containing renewable power generation were conducted under various disturbances to prove the effectiveness of the proposed method.
Farrukh Hafeez
· 2023
This paper is all about generating electricity when people walk on the Floor. Think about the forces you exert which is wasted when a person walks. The idea is to convert the weight energy to electrical energy The Power Generating floor intends to trans- late the kinetic energy to the electrical power. Energy Crisis is the main issue of world these days. The motto of this research work is to face this crisis somehow. Though it won’t meet the requirement of electricity but as a matter of fact if we are able to design a power generating floor that can produce 100W on just 12 steps, then for 120 steps we can produce 1000 Wattand if weinstall such type of 100 floors with this system then it can produce 1MegaWatt. Which itself is an achievement to make it significant
Jinn‐Chang Wu, Kuen‐Der Wu, Hurng‐Liahng Jou et al.
IET Renewable Power Generation · 2014
A seven‐level active power conditioner (SLAPC) used to inject the real power of the clean power source into the grid is proposed in this study. This SLAPC is composed of a four‐level DC–DC power converter and a full‐bridge inverter. The four‐level DC–DC power converter converts the output voltage of the clean power source into a four‐level pulse voltage. The full‐bridge inverter is switched at low frequency and synchronised with the utility voltage and the output voltage of SLAPC is a seven‐level AC voltage. Accordingly, the switching power loss, harmonic distortion and electromagnetic interference caused by the switching operation of power electronic switches are reduced because of the four‐level in the DC side and the seven‐level in the AC side of the full‐bridge inverter. In addition, the proposed SLAPC acts as an active power filter that filters out the harmonic current of the load, so the utility current of the proposed SLAPC is a sinusoidal current and in phase with the utility voltage. A hardware prototype is developed to verify the performance of the proposed SLAPC. The experimental results show that the performance of the proposed SLAPC is as expected.
Xiurong Zhang, Shaoqian Fan, Daoliang Li
IET Renewable Power Generation · 2025
Abstract The large‐scale integration of new energy generation into the power transmission network introduces uncertainty and fluctuations, posing a threat to the secure operation of the transmission network. Modelling and analysing the uncertainty in photovoltaic (PV) generation is essential. This paper introduces a method for generating scenarios for centralized PV station based on spectral normalization generative adversarial networks (SNGAN). Data‐driven scenario generation methods, with generative adversarial networks (GAN) as representatives, are commonly used today to analyse the uncertainty of new energy generation. In addressing the uncertainty of centralized PV power generation, this paper introduces SNGAN, makes improvements to the discriminator, enhances training stability, and generates PV power generation scenarios. The incorporation of spectral normalization as a regularization technique contributes to the stability and convergence of the proposed GAN model. The effectiveness of the selected method is validated through comparisons with actual data.
Edwin Polido, James P. Ulery, Francis A. Di Bella
ASME 2005 Power Conference · 2005
Off shore wind turbine farms are becoming more popular as the efficiency and per unit cost of the systems become more economical. Wave power generating systems have been conceptualized for centuries but only relatively recently, since the 1970’s, has private and public financial support been forthcoming to provide some model and full-scale testing. Northeastern University researchers are studying the integration of these two technologies. The objective is to reduce the combined cost per kW for the power generating system by accomplishing two distinct improvements: 1. sharing the electrical and civil engineering systems that are common to the integrated design, and 2. storing the ocean wave energy for use later when the wind energy is not sufficient to produce maximum wind turbine power. Several new concepts for wave power generation and storage are identified in the process. This paper will describe the current research at Northeastern University and the preliminary designs for the integrated wind turbine generator and wave power system using state-of-the-art wind turbines and air expander systems.
Sachin Tiwari, Seema Kewat, Bhim Singh et al.
IET Renewable Power Generation · 2021
Abstract In this paper, a battery‐supported unified power quality controller (UPQC) for a small hydro‐based isolated power generation is investigated as a voltage and frequency controller. The self‐excited squirrel cage induction generator driven by constant power prime mover (small hydro turbine) has unacceptable voltage, frequency and power quality under non‐linear loads. The battery‐supported UPQC‐based voltage controlled‐voltage source converter is designed, modelled and simulated in MATLAB environment. Here UPQC has series and shunt converters with a battery and it is used to feed the local loads. This small distributed power generation system is capable to feed unbalanced non‐linear loads because a shunt converter is used to take care the compensation of unbalanced loads and it always maintains the source currents balanced and sinusoidal. Moreover, a series converter is used to inject the series voltages in the self‐excited squirrel cage induction generator terminals to regulate the common coupling point voltage during unbalanced non‐linear loads. Performance of a battery‐supported UPQC is also validated experimentally using a laboratory prototype of a 3.7 kW, 230 V, 50 Hz capacitor excited induction generator.
Wenjuan Du, Xiao Chen, Haifeng Wang
IET Renewable Power Generation · 2018
The authors study the modal condition, under which the sub‐synchronous oscillations (SSOs) may be caused by the grid integration of a permanent magnet synchronous generator (PMSG) in a power system. The study is conducted by using a closed‐loop interconnected model of the power system with the PMSG, which consists of a PMSG subsystem and a subsystem of the remainder of power system (ROPS). The modal condition is the nearness of an SSO mode of open‐loop PMSG subsystem to an SSO mode of open‐loop ROPS subsystem on the complex plane. It is named as the open‐loop modal coupling (OLMOC). The study shows that when the OLMOC takes place, strong sub‐synchronous interactions (SSIs) are induced by the PMSG and may very likely decrease the damping of SSOs in the power system. A formula to approximately evaluate the degree of damping decrease caused by the OLMOC is derived in this study. Hence, the mechanism of why the PMSG may jeopardize power system stability is revealed from the viewpoint of open‐loop modal condition. Study cases are displayed to confirm the analytical investigation. They indicate that the growing torsional SSOs and the SSIs between the PMSGs take place when the OLMOC occurs.
Hideyuki Aoki, Yohsuke Matsushita, Tsuyoshi Yamamoto et al.
2002 International Joint Power Generation Conference · 2002
A wood chip combustion behavior in a turntable type moving bed combustor is numerically analyzed in order to understand the fundamental combustion behavior in the combustor. An experiment is also carried out to compare the experimental data with numerical results and estimate the performance of the numerical analysis. Wood is used as building materials in most countries, and wooden house is the most popular in Japan. In some countries such as Japan, the period of durability of wooden house is for several decades because of high humidity and warm weather. A great amount of wooden waste is disposed and buried every year. From a viewpoint of effective use of energy, these kind of wooden wastes should be converted to valuable source of energy by efficient combustion operation. It is however difficult to operate the wooden waste conversion system because this waste includes other material such as plastics, plaster board, stone and soil. These kinds of intermingled material cannot be separated easily from wooden waste. In this study, we develop the turntable type moving bed combustor which effectively discharges the intermingled material from the combustor. We also develop the numerical model for the analysis of the combustor. The turbulent gas flow in the combustor is described by k-ε two-equation model and a momentum exchange between gas and moving bed of wood chip is considered. A solid phase is assumed to be a Newtonian fluid. Gas and solid phase temperature are calculated with considering convective and radiative heat transfers. Devolatilization reaction of wood is calculated by a first order chemical reaction model. Chemical reactions of gas and solid surface are also calculated with considering both chemical and gas film diffusion rates. Governing equations above-mentioned are simultaneously solved by control volume method. The geometry of the combustor is 470 mm in diameter and 1,500 mm in height. The combustion air is introduced tangentially from side wall. Wood chip is fed by screw feeder from side wall. Wood chip feed rate is 50 kg/hr, initial temperature of wood chip is 293 K and air ratio is 1.2. Numerical results are fairly in good agreement with experimental data. High temperature and low oxygen gas which contains unburned CO near centerline region of the combustor is observed in both experimental and numerical results. The mixing promotion of this fuel containing gas and oxygen rich gas near sidewall region is a problem of the development of efficient energy conversion system. This combustor would be one of the heat sources for a steam-driven electric power plant utilizing wooden waste as the source of fuel in local area.
Yoichi Tone, Kunihiko Mouri
2002 International Joint Power Generation Conference · 2002
For the near future business application, the new idea of the distributed energy network system is proposed to secure lower cost and highly reliable power and heat supply system for the limited local area such as high energy density urban area. In Japan, tariff of the electric power is same for urban consumers and rural consumers under the present power law. However the wave of the power deregulation may affect to small business users and home users and the free-market of power purchase may emerge in public domain. Towards the realization of the future active power market, the new idea is created to promote the intelligent distributed power generation systems and heat utilization systems using the Internet application and local energy network construction. This system has been discussed in the consortium, consisting of Nagoya University, Gas Company, Power utility, Trade Company, IT Company etc since May 2000. The idea of the proposed eL-power network system is to supply necessary power and heat to the only customers in the high energy density area like near the railway station using energy management by mean of the Internet technologies.
Alexander I. Kalina
1983 Joint Power Generation Conference: GT Papers · 1983
A new thermodynamic energy cycle has been developed, using a multicomponent working agent. Condensation is supplemented with absorption, following expansion in the turbine. Several combined power systems based on this cycle have been designed and cost-estimated. Efficiencies of these new systems are 1.35 to 1.5 times higher than the best Rankine Cycle system, at the same border conditions. Investment cost per unit of power output is about two-thirds of the cost of a comparable Rankine Cycle system. Results make cogeneration economically attractive at current energy prices. The first experimental installation is planned by Fayette Manufacturing Company and Detroit Diesel Allison Division of General Motors.
Akshay Kumar, Gauri Shankar
IET Renewable Power Generation · 2018
In recent years, power utilities have witnessed increase in penetration of tidal power generation plant (TPGP) into the power system network and, hence, it may collaborate with conventional units in frequency regulation process to ensure power system stability. Therefore, this study presents a method to monitor the participation of TPGP in load frequency control mechanisms in the presence of conventional unit such as diesel power generation plant. The participation of TPGP is showcased based on primary frequency control topologies such as by producing additional inertia, additional damping along with the concept of deloading operation. These approaches are realised by employing conventional controllers to obtain required power (corresponding to different loading conditions) from TPGP by manipulating the kinetic energy of the rotating mass of tidal turbine blades. For better performance and improved stability of the system, the controller parameters are optimised using quasi‐oppositional harmony search algorithm (QOHSA). The effectiveness of QOHSA is proved by comparing the results obtained by it to those yielded by employing other existing state‐of‐the‐art optimisation methods. The prospective analysis is validated in single‐area and two‐area hybrid power system models through MATLAB simulation studies.
Gary W. Bostick, Russ Tinkham
1989 Joint Power Generation Conference: GT Papers · 1989
Public Service Company of Oklahoma (PSO) operates a combined cycle, Westinghouse PACE generating station which was commissioned in 1972. The plant consists of two Westinghouse 501B6 gas turbines, two heat recovery steam generation units with afterburners, and a single 120MW steam turbine generator. PSO made the decision to upgrade the complete plant control with a state-of-the-art triple modular redundant control system, designed to provide entire control of the generating station. The paper describes the overall retrofit project, from project conception and justification through installation, commissioning and operating results.
Niina Helistö, Juha Kiviluoma, Hannele Holttinen
IET Renewable Power Generation · 2018
This study presents the potential role of thermal power generation in a future power system with high shares of variable generation while considering different sources of demand side flexibility such as heat pumps and heat storages in district heating, demand response from industries and electric vehicles. The study was carried out using a generation planning model combined with a unit commitment and economic dispatch model. The results from the planning model show a strong shift away from combined cycle gas turbines to open cycle gas turbines and gas engines as the share of wind power and solar photovoltaic increases. Demand side flexibility measures pushed this trend further. The results from the unit commitment and economic dispatch model demonstrate that the flexibility measures decrease the ramping frequency of thermal units, while the ramp rates of thermal units remain largely unchanged or increased. This indicates that the flexibility measures can cover smaller ramps in the net load more cost‐effectively but that thermal power plants are still valuable for larger ramps. Impacts on emissions and electricity prices are also explored.
John A. Charest, Sarah Witt
2003 International Joint Power Generation Conference · 2003
Deterioration of components and structures at power generating facilities has caused unscheduled plant outages, personnel safety concerns, and significant impact on operating budgets. However, a new technology is now available that can increase the usable life of components and structures, while significantly reducing the economic burden normally associated with repair or replacement options. This technology, known as “Fiber Reinforced Polymers” or FRP, utilizes carbon fibers and high strength epoxy resins to restore or enhance the structural and or pressure boundary capacity of plant equipment and structures. This technology utilizes the high strength of the carbon fibers to add additional structural capacity to the existing member. This is accomplished through the superior adhesive bond provided by the epoxy. The design determines the orientation of the fibers to add strength in the direction of static and dynamic loading conditions. The repairs to the affected items are performed in-place and completed during relatively short durations. Small crews perform the work and can do internal strengthening with access through only a manhole. Power generation facilities and electrical transmission/distribution networks have typically shunned the use of composite materials to rehabilitate structures or components. The technology and engineering associated with FRP repair methods provides an effective mechanism to rehabilitate piping, pumps, heat exchangers, water boxes, structural shapes and numerous other items while minimizing the cost typically associated with direct replacement.