biomass-based power systems

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COMBUSTION AND GASIFICATION OF SOLID BIOMASS FOR HEAT AND POWER PRODUCTION IN EUROPE STATE-OF-THE- ART AND RELEVANT FUTURE DEVELOPMENTS

COMBUSTION AND GASIFICATION OF SOLID BIOMASS FOR HEAT AND POWER PRODUCTION IN EUROPE STATE-OF-THE- ART AND RELEVANT FUTURE DEVELOPMENTS

CHP technologies based on biomass gasification are currently at the development and demonstration stage but have not yet reached a level of development which allows full commercial applications. Several promising demonstration plants, however, have been erected over the past few years and some of these are in operation for several thousands of hours, which shows the future potential of this technology. An interesting development for small-scale applications in this respect is the Pyroforce gasification system. The technology, which is based on an atmospheric air-blown downdraft fixed bed gasifier, has been demonstrated successfully, market introduction is currently starting. The updraft gasification system demonstrated at Harboore (DK) is a rather mature technology with a good partial load behaviour. The disadvantage of this technology is the fact that the product gas contains high amounts of tars, which makes a complex and expensive gas cleaning system necessary in order to utilise the gas in an internal combustion engine. The circulating fluidised bed biomass steam gasification process in Güssing (A) has proven its technological maturity and has been successfully operated with a gas engine for approx. 28,400 hours until September 2007. Weak points are the complexity of the system, the rather high operating costs and the moderate electric efficiency of the first demonstration plant. In this respect, development activities are ongoing at present in order to enhance the electric plant efficiency of the process by coupling the gasifier with an ORC unit. This technology is mainly applicable for large-scale systems (>2,000 kW el ).
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Using biomass-based fuels including pyrolysis liquids for power and CHP production

Using biomass-based fuels including pyrolysis liquids for power and CHP production

The European Commission has set a target to increase the share of combined heat and power (CHP) in the European energy supply to 18% in 2010. In Russia, there is a need for small-sale power production that can serve remote communities, industrial users and commercial users. In both the EU and the Russian market small-scale (50 to 1000 kWe), direct biomass-to- electricity CHP-systems can help fill the need. However, to date the implementation of such bioenergy systems has had relatively limited success. Some of the main reasons for this lack of success include:
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Optimal Utilization of Renewable Energy in Aquaponic Systems

Optimal Utilization of Renewable Energy in Aquaponic Systems

This paper presents a method based on a network flow problem formulation to determine the optimal energy supply mix for aquaponic systems under con- sideration of the daily profiles for electricity, heat and water pumping demand. The objective is to minimize demand deficit, while maximizing the utilization of renewables at low exchange with the power grid. Hence, a basic understanding of aquaponics is vital and required. Aquaponics can be described as an energy efficient method of producing food particularly in comparison to conventional hydroponics and aquaculture systems. This is predominately because the com- bination of the two techniques allows the energy costs to be shared. Aquaponic systems on the whole operate within a controlled environment for year round production and this requires an energy input of some kind particularly in tem- perate climates. Essential components such as the pump and aerators may be mechanically powered via a non-electrical means e.g. via foot or gravity. This may not be possible however in larger systems or where a high level of automa- tion is required and so in most aquaponic systems it is strived to integrate re- newable energy technologies within the systems wherever possible. The novelty of the model lies in the prioritization of renewable energy source for allocation based on the produced-energy form and requested-energy form, i.e. , why use electrical energy produced by PV for heating if there direct is heat energy from biomass of flat plate solar collector. Therefore, many different priority constraints
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Nigerian Wood Waste: A Dependable and Renewable Fuel Option for Power Production

Nigerian Wood Waste: A Dependable and Renewable Fuel Option for Power Production

Being an oil-rich country, Nigeria’s energy supply is primarily fossil-based. The unequal distribu- tion of oil wealth, along with agitation for self-determination and resource control, has led to the sabotage of oil installations. This, in turn, has affected all services running on the energy supply from these installations, leading to incessant or total shut-down of such facilities. Power generated using biomass-based renewable energy technologies is a promising option in limiting the coun- try’s dependence on fossil energy for power generation. The most important part of this option is on-site power generation via mini-grid systems. The power thus produced is utilized with the excess being fed into the national grid based on Feed-in-Tariff (F.i.T.) requirements and techni- calities. The important factors to be considered in the propagation of a mini-grid option are ex- amined in this study. Furthermore, the study shows that about 1.3 TWh of electricity can be gener- ated from the 1.8 million tonnes per year of wood waste produced by the lumber industry in Nige- ria. Power generation through the utilization of biomass has however proved to be a possible path in achieving economic, social and environmental sustainability in the country. Economic studies show that for small-scale power generation, internal combustion engines and Stirling engines are economically feasible. Steam turbines and gas turbines are mostly used in medium/large-scale biomass power generators, especially in proximity to biomass waste resources. Micro gas turbine power technology can also be applied on a small scale despite its high total investment capital.
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Harmonics Distortion Analysis of Multipulse Converter
                 

Harmonics Distortion Analysis of Multipulse Converter  

There are two types of conversion techniques , one is uncontrolled in which diodes are implemented and other is controlled in which thyristors are implemented respectively [8].The performance improvement is achieved for total harmonics distortion (THD) in input current, DC voltage ripples and form factor. Three-phase controlled rectifiers have a wide range of applications, to large high voltage direct current (HVDC) transmission systems from small rectifiers. They are used for electrochemical processes, wide range of motor drives, controlled power supplies, traction equipment and other applications.
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Evaluation of co-firing as a cost-effective short-term sustainable CO2 mitigation strategy in Germany

Evaluation of co-firing as a cost-effective short-term sustainable CO2 mitigation strategy in Germany

We consider the dynamics of the electricity market by the usage of a MOM. Our MOM is based on data from the German electricity market in the year 2010. For this year, the most recent and complete dataset was available at the point in time when our MOM was implemented. The load profiles of the reference year 2010 were then adapted to the year 2020. We chose the year 2020 as tar- get year since we wanted to answer in a retrospective way the question of whether co-firing would have been an effective measure to achieve the climate targets for 2020. Nevertheless, a big advantage of our method is the transferability of the model to a more recent database and to a target year in the distant future. To enhance reproducibility, we also describe our method in a very detailed way. In order to enable the consideration of various conceivable developments in the German electri- city market, the MOM is simulated for eight scenarios that are based on eight different energy pathways.
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Supply and Demand of a Forest Biomass in Application to the Region of South East Finland

Supply and Demand of a Forest Biomass in Application to the Region of South East Finland

In Finland it is estimated that forest biomass will be the main source of bioenergy when meeting the national target: 38% renewable from total energy consumption by 2020. This target must become concrete for regional and local level participators of a forest industry and actions should take place in large combined heat and power generation (CHP) plants, district heating plants and independent heating systems. In energy production replacing fossil fuels with renew- able energy is reasonable in many cases. However, there are usually doubts about the availability and security of supply of forest biomass. The aim of this study is to introduce a systematical method for analyzing the availability and demand of forest biomass in regional and local level. This study introduces an objective method for analyzing local possibilities on where and how much the use of forest biomass could be increased. By replacing use of fossil fuels with renewable and domestic energy sources carbon dioxide (CO 2 ) emissions and dependency on imported fossil fuels can be reduced.
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An overview on biofuel and biochemical production by photosynthetic microorganisms with understanding of the metabolism and by metabolic engineering together with efficient cultivation and downstream processing

An overview on biofuel and biochemical production by photosynthetic microorganisms with understanding of the metabolism and by metabolic engineering together with efficient cultivation and downstream processing

Flux balance analysis (FBA) based on the network con- sisting of 484 metabolic reactions and 458 intracellular metabolites for C. reinhardtii indicates that aerobic het- erotrophic growth on acetate has a low yield on carbon, while mixotrophically and autotrophically grown cells are significantly more carbon efficient [117]. A genome- scale extension for C. reinhardtii has been made with the network consisting of 1,080 genes, associated with 2,190 reactions and 1,068 metabolites (named iRC1080), that enables quantitative growth prediction for a given light source, resolving wavelength and photon flux. This offers insight into algae metabolism and potential for gen- etic engineering and efficient light source design [118]. Another comprehensive literature-based genome-scale model with the network of 866 ORFs, 1,862 metabolites, 2,249 gene-enzyme-reaction-association entries, and 1,725 reactions has been developed (named AlgaGEM), where it predicted observable metabolic effects under autotrophic, heterotrophic, and mixotrophic conditions, and predicts increased hydrogen production when cyclic electron flow is disrupted, and the physiological pathway for H 2 produc-
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Reduction of Harmonics & Improve Efficiency Using Multi Pulse Converter
                 

Reduction of Harmonics & Improve Efficiency Using Multi Pulse Converter  

165 Multipulse converters are converters providing more than six pulses of DC voltage per cycle from AC input or the converter having more steps in AC input current than that of six pulse bridge rectifier supply current. Phase shifting transformers are used to derive multipulse phase supply from three-phase AC mains using different combinations of transformer windings such as star, delta, zigzag, polygon, fork etc. In this thesis we use zigzag transformer. The phase-shifting transformers play a key role in the multi-pulse rectifier's performance. Jiaopu et.al [1] discussed commonly used basic connections of phase-shifting transformer, such as Scott, polygon, star/delta, extended-delta and zigzag and gave the analyses and comparisons between them. Focusing on 12-pulse phase-shifting transformers, the research highlighted possible strategies from basic connections to 12-pulse phase-shifting transformers which illustrate the evolution and its basic principles which may be extended to higher pulse converters. Singh et.al [3] analyzed the performance of multi-pulse electronic load controller for isolated asynchronous generator, as load controller conventional electronic based six pulse uncontrolled rectifier contains large content of harmonics. A comparative study of three phase controlled multi pulse converters was presented by [4] for biomass, gas turbine, wind system based power plant, diesel, hydro, , and incorporated input current shaping of controlled rectifier using multi- pulse current shaping concept. The author Xigeng et.al [6] introduced the realization of phase-shifting of the multi-pulse converter transformer and the
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Techno Economic Assessment of Hybrid Renewable Energy Systems Based on Power to Hydrogen and Methane Gas Concepts

Techno Economic Assessment of Hybrid Renewable Energy Systems Based on Power to Hydrogen and Methane Gas Concepts

Abstract: This paper deals with the techno-economic study of the hybrid renewable energy system based on energy storage aspect under the form of hydrogen and methane. Indeed, with the intermittency of the renewable energy sources such as photovoltaic and wind energy, several problems of produced energy injection to the power system network can be encountered due to the shortage or the excess of these sources. This situation appeals the use of systems that ensure the stability of network based on the storage of energy surplus into gas using electrolyzer systems, which will be used afterward to cover the eventual shortage. In the present paper, the study of performance of each pathway of methane and hydrogen storage has been performed by the treatment of multiple scenarios via different architecture case studies in an Algerian location. Whereas, the energy produced by the photovoltaic system, the wind energy and the gas micro turbine sources are considered similar in each case. The modeling and simulation of the studied system operation under optimization criteria has been performed in this work, where the main aim is to define the appropriate configuration taking into account the different with low costs of investment, maintenance operation and immediate reactivity with a big storage capacity. Keywords: Hybrid renewable energy; Electrolyze; Hydrogen; Methane; Power to Gas Concept.
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Resource allocation for relay based green communication systems

Resource allocation for relay based green communication systems

Recently, the markets in North America, Asia and Europe have launched the 3.9G standards, worldwide interoperability for microwave access (WiMax) and long term evolution (LTE) systems. Based on the IEEE 802.16 protocol, WiMAX can provide broadband access with downlink and uplink speeds up to 75 Mbit/s and 25 Mbit/s, respectively. Meanwhile, the current LTE, which belongs to 3rd generation partnership project (3GPP) release 8, offers up to 326.4 Mbit/s and 86.4 Mbit/s as the peak down- link and uplink data rates. After 30 years of development from 1G, it is so surprising to see that the data rate of LTE is 5,800 times of the peak data rate of AMPS in downlink (the peak data rate of AMPS is 56 kbit/s)! While, the pursuing of higher data rate in wireless communication never stops. Developed from WiMAX and LTE, WiMAX 2 and LTE-Advanced were proposed in 2011 as the 4G standards to support peak downlink data rate up to 1 Gbit/s and peak uplink data rate up to 500 Mbit/s [42]. In LTE-Advanced systems, relay and coordinated multipoint (CoMP) techniques are adopted to help improve the cell-edge performance [12] [43]. How about the 5G network? It is believed that millimetre-wave communication is one of the promising solutions to the future 5G standard [44] [45], while there are still many issues need to be addressed. Chapter 5 introduces some technical details about power consumption of millimeter-wave communication systems. All the aforementioned wireless communica- tion techniques are summarised in Table A.1 of Appendix A. As shown in the table, it can be observed that in the early days of wireless communication, each country had her own standards. While with the tendency of globalisation, the boundaries of standards between countries have been merging.
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Review of ship microgrids: system architectures, storage technologies and power quality aspects

Review of ship microgrids: system architectures, storage technologies and power quality aspects

The simplified representation of an IPS shown in Figure 2 can be used as an example system to discuss further on the time constants of different components and their implications. In this system, four steam-turbine-driven generators are used as the sources. The starboard and port propulsion motors are fed through power electronic converter systems. Depending on the required power level, propulsion motor could be chosen as either an induction motor (up to 5 MW) or a synchronous motor (above 5 MW) [13]. Permanent magnet (PM) motors are also increasingly being used in electric ship applications [15]. Irrespective of the type of the motor, its dynamics are affected by the rotor time constant. A typical fixed-pitch, variable speed, propulsion drive system in an ac ship includes a back-to-back converter structure for rectification of the ac power to dc and then inversion to produce variable voltage and variable frequency output to the motors. The rectifier stage is not required in dc ships and thus only the inverter stages are used to control the propulsion motors. The typical time constants of the propulsion drive system based on industrial drives up to 20 MW is identified in [17]. The propeller run-up time depends on the size and inertia of the propulsion system and can be found to be within the range of 1–60 s. Following propeller run-up, the ship run-up time is from 60 to 500 s [17]. While these are comparatively longer time transients, the short-term transient that impact the power system include the dynamics of the machine and the pulse width modulation (PWM) drive. The PWM switching transients in the range of 100 ns to 1 µ s are filtered within the power electronic converter itself. However, the dynamics of electrical machines are in the range of 1 ms to 1 s and thus they will significantly influence the ship power quality depending on the ability to supply rapid changes in power demand.
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Stackelberg game based precoding and power allocation for spectrum auction in fractional frequency reuse cognitive cellular systems

Stackelberg game based precoding and power allocation for spectrum auction in fractional frequency reuse cognitive cellular systems

In our earlier work [36], we have studied a spectrum auction problem under the assumption that the bidding and valuation of SUs take a random number in a certain range. In fact, they are often related to the channel cap- acity or channel quality (typically SINR). Therefore, we make some corresponding improvements of it to design a more effective spectrum auction algorithm. Besides, given the excellent properties of all the above technolo- gies, in this paper, through an optimal interference price announced by the PU, a joint precoding and power allo- cation algorithm via Stackelberg game (OIPPS) is pro- posed to solve the spectrum auction problem subject to the interference constraint of PU, the transmission power constraint of SUs, and the signal-to-interference- plus-noise ratio (SINR) constraint of each SU. The major contributions of this paper are summarized as follows:
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A Novel Hybrid Non Isolated Distribution Generating System Based on Wind and Wave Power Generation Systems Using a DC Microgrid
A Rajasekhar Reddy, Y Narayana Rao & Dr A Purna Chandra Rao

A Novel Hybrid Non Isolated Distribution Generating System Based on Wind and Wave Power Generation Systems Using a DC Microgrid A Rajasekhar Reddy, Y Narayana Rao & Dr A Purna Chandra Rao

Power converters introduce some control inputs for power conversion. In this case, the structure of the control system can be divided into different levels. The switching control unit is designed for each power converter. In this, the drivers with PWM generate the transistors ON/OFF signals from the ideal states of the switching function and the modulation technique determines the switching functions from the modulation functions. The automatic control unit is designed for each energy source and its power conversion system. In an ACU, the control algorithms calculate the modulation functions (m) for each power converter through the regulation of some physical quantities according to their reference values. The power control unit is designed to perform the instantaneous power balancing of the entire HPS in order to satisfy the grid requirements.
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Flexible Co Combustion of High Ratios of Sustainable Biomass with Coal in Oxy CFB Boiler for CO2 Capture

Flexible Co Combustion of High Ratios of Sustainable Biomass with Coal in Oxy CFB Boiler for CO2 Capture

Preventing the possible negative effects of growing biomass supply will, in the longer term, require a process-oriented development of refined criteria and in- dicators involving relevant stakeholders. International work is already taking place to ensure that communities, biodiversity and land are protected and a number of certification schemes and sustainability initiatives are already in place, e.g. for biofuels. As it is difficult to trace such effects, this is a widely dis- cussed subject. The European Commission has organised consultations on how to address indirect land-use change (ILUC) within existing sustainability criteria for biofuels on the EU market and it is already being addressed.
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A Relay Based Controller Designing of Hybrid Power Systems

A Relay Based Controller Designing of Hybrid Power Systems

It's something of an uncomfortable fact that civilized society is almost completely reliant upon fossil fuels for nearly every aspect of its existence. While fossil fuels have been integral in the development of most industrial nations, there are a few realities of using them that society needs to come to terms with. There are many arguments in favour of society's need for renewable energy. It's a fact that the climate is changing and that fossil fuel emissions are contributing greatly to that change. By contrast, solar energy panels and wind turbines generate zero emissions in their generation of electricity. By recent Greenpeace estimates, the world could save around $180 billion a year by switching 70% of the planet's electricity production to renewable options. While this alone is an excellent economic argument in favour of renewable energy, the truth is that the sheer savings involved aren't the only economic factors that support the use of renewable energy as a positive way forward. Some local markets are already starting to gain access to renewable energy options in their local power grid that have them saving more money than with traditional fossil fuel sources. Historically, coal powered the Industrial revolution but when $5 barrel oil began to flow, coal declined in importance until the oil embargo which brought it back into importance.
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Reaction Pathways of Biomass-Derived Oxygenates on Noble Metal Surfaces

Reaction Pathways of Biomass-Derived Oxygenates on Noble Metal Surfaces

As the global demand for energy continues to rise, the environmental concerns associated with increased fossil fuel consumption have motivated the use of biomass as an alternative, carbon-renewable energy feedstock. Controlling reactive chemistry of the sugars that comprise biomass through the use of catalysis becomes essential in effectively producing green fuels and value-added chemicals. Recent work on biomass conversion catalysts have demonstrated the efficacy of noble metal catalyst systems for the reforming of biomass to hydrogen fuel, and the hydrodeoxygenation of biomass-derived compounds to value-added chemicals. In particular, Pt and Pd surfaces have shown considerable promise as reforming catalysts in preliminary aqueous phase reforming studies. It becomes important to understand the mechanisms by which these molecules react on the catalyst surfaces in order to determine structure-activity relationships and bond scission energetics as to provide a framework for engineering more active and selective catalysts. Fundamental surface science techniques provide the tools to do this; however, work in this field has been so far limited to simple model molecules like ethanol and ethylene glycol. Herein, temperature programmed desorption and high resolution electron energy loss spectroscopy are utilized in an ultra-high vacuum surface science study of the biomass-derived sugar glucose on Pt and Pd single crystal catalysts. Overall, it was determined that the aldehyde function of a ring-open glucose molecule plays an integral part in the initial bonding and reforming reaction pathway, pointing to the use of aldoses glycolaldehyde and glyceraldehyde as the most appropriate model compounds for future studies. Furthermore, the addition of adatom Zn to a Pt(111) surface was found to significantly decrease the C-H and C-C bond scission activity in aldehyde containing compounds, resulting in a preferred deoxygenation pathway in opposition to the decarbonylation pathway common on clean Pt(111). This has implications in the hydrodeoxygenation of biomass-derived compounds for the production of value-added chemicals like 2-methylfuran from furfural, or the catalytic upgrading of sugars. Ultimately, identification of the reactive mechanisms of biomass-derived molecules on different unique surfaces has lead to a greater understanding for what makes a more selective catalyst for specific chemical pathways.
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Energy positive wastewater treatment and sludge management

Energy positive wastewater treatment and sludge management

nutrient compounds such as nitrogen and phosphorous elements, toxic inorganic and organic pollutants which include heavy metals such as Cd, Cr, Cu, Ni, Pb, Zn, and Hg and polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), dioxins, pesticides, linear-alkyl-sulfonates, nonylphenols, polybrominated fire retardants, etc., pathogens and other microbiological pollutants, inorganic compounds such as siliates, aluminates, and calcium and magnesium containing compounds [2, 3]. The organic portion contains 50– 55% carbon, 25–30% oxygen, 10–15% nitrogen, 6–10% hydrogen, 1–3% phosphorus and 0.5–1.5% sulfur. Nontoxic organic and nutrient compounds can be utilized to grow the microbial biomass to produce sludge which can be processed for energy recovery. Energy recovery from wastewater can be achieved in three viable configurations as shown in Figure 1. Strategy 1 includes anaerobic digestion of sludge collected from primary and secondary treatment units to meet the treatment energy expenses. However, this alone may not be adequate to generate all the energy required for wastewater treatment due to technological and scientific barriers that prevail in these systems. Instead integration of other organic wastes for co-digestion can be considered. Strategy 2 involves wastewater treatment with mixotrophic systems (i.e., bacteria and algae) to enhance carbon utilization, nutrient removal and biomass production. Strategy 3 is to use secondary effluents from the wastewater treatment plants to cultivate algae for biofuel production through thermo-chemical processes whether on-site or off-site.
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ESTIMATION OF POWER GENERATION POTENTIAL FROM BIOMASS PRESENT IN MELGHAT-A CASE STUDY

ESTIMATION OF POWER GENERATION POTENTIAL FROM BIOMASS PRESENT IN MELGHAT-A CASE STUDY

The first step to estimate the data for power generation is field surveys based on household and direct interview methods. A baseline questionnaire was made and a survey was conducted in the village and all information regarding the village like agriculture, population, houses, occupation, school, biomass available was gathered. After collecting the data power required by the village was calculated and the biomass available in the village was estimated .Then the calorific values of all the biomass present was found and the estimation was made how much power can be generated through the available biomass.
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Optimal Power Allocation and Power Constraint in OFDM-Based Cognitive Radio Systems

Optimal Power Allocation and Power Constraint in OFDM-Based Cognitive Radio Systems

Where the LU's bandwidth is B, and CUs separate in the two sides of LU. The interval of every subcarrier in the CU band, and the interval between LU band and CU band are both ∆ f. The sum of subcarriers in the band of CU is N. Because the OFDM modulation mode is used both in CUs and LU (the attenuation characteristic of power spectral density side lobe), the LU and CUs both have interferences on each other. 2.1. Interference Introduced by Cognitive User's Signal

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