a techno-economic feasibility assessment on small-scale ... · different types of gasification...

Applied Mathematical Sciences Vol. 8, 2014, no. 131, 6565 - 6576

HIKARI Ltd, www.m-hikari.com http://dx.doi.org/10.12988/ams.2014.46450

A Techno-Economic Feasibility Assessment

on Small-Scale Forest Biomass Gasification

at a Regional Level

Daniele Dell’Antonia

Department of Agriculture and Environmental Sciences (DISA)

University of Udine, Via delle Scienze 208, Udine, Italy

Sirio R. S. Cividino



Olga Malev



Gianfranco Pergher



Rino Gubiani



Copyright © 2014 Daniele Dell’Antonia et al. This is an open access article distributed under the

Creative Commons Attribution License, which permits unrestricted use, distribution, and

reproduction in any medium, provided the original work is properly cited.

Abstract

In recent years public and political awareness to environmental issues and

energetic aspects have led to the development of alternative energy resources. The

6566 Daniele Dell’Antonia et al.

use of woody biomass from forest management presents a renewable, low-carbon

feedstock which can implement alternative sources for energy production. For

example, biomass gasification is a prominent conversion route for producing a

renewable clean feedstock used for power generation.

In 2012, the "burden-sharing" Decree 28/2012 of the Italian Ministry of Economic

Development introduced regional targets for Friuli Venezia Giulia region with an

increase of 257 ktoe produced from renewable energy equal to 12,7% of the

regional consumption. The present work was focused on overall mountain area of

this region in the North-East of Italy. The study showed technical and economic

aspects of forest combined heat and power (CHP) biomass system with two

different types of gasification plants: (i) gasification with combustion engine and

(ii) gasification with a Stirling engine. The technical and economic characteristics

of small-scale gasification technology was determined using the methodology of

Net Present Value (NPV) in order to identify the best technological solution for

the construction of a gas plant in a company that processes timber:

From the technical point of view the gasification plant with Stirling engines is a

more reliable energy system which is not subjected to strains due to the use of

synthesized gas during its normal activity. However, the investment costs are

significantly higher (€ 7,429/kWe) when compared to the costs necessary for a

gasifier with internal combustion engine (€ 4,040/kWe). The techno-economic

feasibility assessment has shown no substantial difference in the remuneration

time for both type of gasification plant being in the range of 4-5 year period.

Additional studies are necessary to elucidate both technical and economic aspects

and to suggest which type of technology is more suitable on small-scale forest

biomass gasification at a regional level.

Keywords: forest, wood biomass, gasification, economic analysis

1 Introduction

Forests play a key role in the overall socio-economic development providing

different material, environmental or occupational benefits and for that reason

increasing resources should be dedicated to forest sustainable management and

conservation. One potentially valuable by-product from conventional forestry

systems which produce wood for constructions and pulp or paper is biomass for

energy [Richardson, 2007]. Today biomass provides about 10% of the global

energy supply, amounting to around 14 PWh per year, of which the main part

(over 80%) originates from wood or shrubs, in form of trees, branches and

residues [Chum, 2011; IEA, 2011]. Woody biomass is regardedas as a “CO2

neutral” solid fuel and a promising alternative to decreasing resources of fossil

fuels [Zhou, 2006]. Biomass gasification is a prominent conversion route for

producing a renewable clean feedstock used for power generation [Wongchanapai,

2012]. Furthermore, use of biomass in district energy creates jobs and promotes

social and economic development in local communities [Openshaw, 2010; Yagi,

2011].

Techno-economic feasibility assessment 6567

In 2011 the energy consumption in Italy was of 168 Mtoe (million tons of oil

equivalent), where all renewable energy resources, including hydropower and

biomass, accounted for 20.2 Mtoe (about 12%) [Eurostat, 2013]. At the moment,

no published data exist on the relative contribution of biomass alone, but some

recent estimation report a total potential contribution of 24-30 Mtoe (about 13.6%)

[ITABIA, 2008]. The use of agro-forestry biomass can contribute to increased use

of renewable sources for energy production considering the latest directives of the

European Union (EU) Energy and Environment Policy that established a new

framework for renewable sources (Directive EC 28/2009; European Commission,

2009).

The Italian Energy Action Plan of 2010 set a target of at least 17% of total

energy generated from renewable sources by 2020 [European Commission, 2009].

In 2012, the "burden-sharing" Decree 28/2012 of the Italian Ministry of Economic

Development introduced regional obligations to ensure the accomplishment of

national 2020 targets. Regional targets for Friuli Venezia Giulia region are

particularly demanding for renewable energy, with a projected increase of 257

tonnes of oil equivalent (12,7% of the regional consumption): +138% in 2020

relative to 2005 [Ministry of Economic Development, 2012].

In relation to targets set both on national and regional level, the quantitative

analyses of strategies for utilizing woody biomass energy sources should be

performed both evaluating the potential resources of bioenergy in different

regions (e.g. forest-rich or with agricultural-land surplus) and identifying the

woody biomass demand within forestry industries, and other possible territorial

complications. In Friuli Venezia Giulia region the presence of highly

discontinuous agricultural activities and issues related to mountain regions make

somewhat difficult the exploitation of biomass for the simultaneous production of

electricity and heat (cogeneration). This problem is in part related to the use of

established technologies that have high power (> 1 MW) requiring significant

amounts of biomass (i.e. steam turbines or Organic Rankine Cycle) and it is in

part related to the lack of utilities with continuous use of heat throughout the year.

In north Italy is active a constant research of new technologies to make highly

applicable small to medium size plants (100-250 kWe) for biomass utilization and

more efficient energy conversion. Two different technologies may be usually

applied for biomass power generation: (i) gasification with internal combustion

engine and (ii) gasification with a Stirling engine. In this way agro-forestry

companies could diversify their income rendering it more stable by taking

advantages of state incentives for electricity production from biomass. In specific,

state incentives and municipal support are higher if the electricity production

derives entirely from forestry and agricultural by-products [Ministry of Economic

Development, 2012]. These technologies for energy generation allow also the

production of biochar, a form of charcoal produced through pyrolysis of

carbon-rich biomass. When this material is applied to agricultural lands it

increases soil water and nutrient retention as well as enhances its fertility while

sequestering carbon [Laird, 2008; Lehmann et al., 2007].

This study was focused on the mountain area of Friuli Venezia Giulia region


(North-East Italy). We showed technical and economic aspects of CHP biomass

system with a small-scale gasification equipment. The biomass fuel considered in

this evaluation was represented by residues of wood processing and wood chips

from forest management procedures. The objective of this research was to find out

the economic feasibility of CHP system on small-scale level in mountain areas in

Italy comparing two different technologies for biomass power generation

2 Materials and methods

2.1 Study site

The study area is located in the Friuli Venezia Giulia region (North-East Italy)

and has a total surface area of 785,648 ha. According to the data of the National

Forests Inventory, the regional forests cover an area of 357,224 ha with an

average wood withdrawal of 170,000 m3 which is the 5% of raw material

requirements in woodworking industries [INFC, 2012]. The regional supply of

raw material is dependent on import from foreign countries with a yearly amount

of 3,000,000 m3 year distributed as follows: 70% panels (wood pulp), 11% chair

industry; 10% furniture; 2% floors and windows and 7% for energy or other uses

[Wood Services, 2010].

2.2 Gasification plants

The feasibility study has considered two different types of gasification plants

in order to identify the best technological solution for the construction of a gas

plant in a company that processes timber (Table 1).

In the first case study was identified a system with nominal power output of

140 kWe formed as follows:

• an updraft gasifier which produces fuel gas from wood chips: in this way it

is possible to avoid the use of filtering systems and use biomass with higher

moisture content;

• four heat generators for gas burning process (to note: direct contact with the

heads of Stirling engines);

• four Stirling engines with electric power unit of 35 kWe each;

• a heat accumulator that acts as a thermal stabilizer and allows the

accumulation of hot water.

The functioning of the system is fully automatized; biomass is loaded from

inside the reactor and subjected to high temperature with a limited oxygen supply

which allows the gasification of introduced materials. The syngas is extracted in

the upper part of the reactor and used to move Stirling engines. Besides electricity

this engine produces also heat used for warming of water contained within the

accumulator.

The second case study has a system with a nominal electric power of 250

kWe and is formed of:


• a downdraft gasifier system with electrostatic filtering system of the syngas;

• a dryer for biomass moisture reduction localized in the inlet of the reactor

that uses the heat of the internal combustion engine;

• two sets of diesel engines with nominal power unit of 125 kWe.

In this system the syngas product is extracted at the bottom of the reactor and

passed through a series of scrubbers and electrostatic filters that allow the removal

of impurities. Consequently, the gas is injected with a small amount of diesel fuel

inside the combustion chamber of an internal combustion engine at the end of the

piston compression phase. The amount of added diesel fuel allows the ignition of

the mixture and starting the engine.

Energy

Gasifier with internal combustion

engine

Gasifier with

Stirling engine

Power

generation

efficiency

(%)

Power

(kW)

Energy (1)

(MWh/year)

Power

generation

efficiency

(%)

Power

(kW)

Energy (1)

(MWh/year)

Electricity 24 250 1,750 17.5 140 980

Thermal energy 45 480 3,360 70 560 3,920

Dispersions 31 295 2,065 12.5 100 700

Total 100 1,025 7,175 100 800 5,600

(1) 7.000 hours/year of energy plant activity

Table 1 – Technical characteristics of gasification plants.

2.3 A techno-economic feasibility assessment

Through the analysis of data on the thermal and electrical power efficiency of

the plant and overall activity hours (7,000 hours/year) it was possible to estimate

the total amount of produced energy by the gasifiers. Total electricity produced in

this way was directly transferred and used by the electrical network, while the

remaining thermal component could be used to meet the energy needs of the

company.

In the case of combined gasifier with internal combustion engine part of the

produced heat is used to dry the introduced biomass (10-15 % final humidity

content). On the contrary, for the system with Stirling engine there are no

particular requirements in relation to the humidity of applied fuel and all heat can

be re-used in the company for other purposes. In our feasibility assessment was

also evaluated the possibility of equipping sawmill with a dryer to allow the

re-use of thermal energy. In this way, a part of company's products could be dried

directly in situ thus avoiding and reducing the costs associated with use of

third-party companies for drying processes.

The technical and economic aspects of small-scale gasification technology

was determined using the methodology of Net Present Value (NPV). Profits from


the sale of produced electricity have been calculated considering the base rate of

the Ministry of Economic Development in 2012, for the production of electricity

from renewable sources (229 €/MWh) added with the incentive for use of heat (40

€/MWh). The used thermal energy has been accounted as non-retrieved costs for

the drying of panels by third-party companies (30 €/t). After determining cost and

profit items it was calculated the expected cash flow for a 20-year investment

period during which remains valid the price for sale of electricity. In addition,

profits form electricity sale are not affected by inflation while remaining incomes

are subjected to these variations. For a more detailed analysis these incomes,

subjected to inflation, were calculated for each year in the whole considered

period. The calculated values were presented as incomes less costs deferred in

time using an interest rate equal to average of inflation adjustments indexes for

the period 1992-2012 (2.7%) [ISTAT, 2014]; using the following function:

CF = Ie − [It ∙ (1 + i)t] − [C ∙ (1 + i)t] (1)

Where:

CF, in €, is the annual cash flow;

Ie, in €, is the incomes from the sale of electricity energy;

It, in €, is the incomes from the re-use of thermal energy;

C, in €, is the cost for the management of the plants;

i, in %, is the interest equal to average of inflation;

t, is the time of the cash flow.

Afterwards, we calculated the cash flows, discounted to present value using

an interest rate equal to 4% and was determined the net present value (NPV) of

the two selected types of plants as follows:

∑ =nt=0

CF

(1+r)t (2)

Where:

CF, in €, is the annual cash flow;

r, in %, is the discount rate;

t, is the time of the cash flow;

n, is the year of the investment period.

3 Results

The first phase of the economic analysis was focused on the evaluation of

individual costs and incomes related to purchase and management of small-scale

gasification plants. The total investment cost for purchase and installation of the

gasification plant with four Stirling engines was equal to 1,040 M €, while the

cost of the gasification plant with internal combustion engines was of 1,010 M €

(Table 2).


Plant Gasifier with internal combustion

engine Gasifier with Stirling engine

Gasifier 875,000 850,000

Dryer 55,000 110,000

Wood chipper 40,000 40,000

Connection to electrical network

10,000 10,000

Expenditures for civil

engineering works 30,000 30,000

Total 1,010,000 1,040,000

Gasifier costs (€/kWe) 4,040 7,429

Table 2 – Investment costs for the construction of gasification plants and associated dryers.

In Table 3 are presented economic accounts relative to costs and incomes of the

annual management of gasification plants. Maintenance costs and necessary

employment for the plant with Stirling engines account for an annual charge of €

31.900, compared to the gasifier with internal combustion engines where the planned

expenses are € 86.580. The relevant difference is due to the high demanding

maintenance of internal combustion engine powered with syngas. Due to this issue it

is considered the cost of 45 €/MWh produced for full-service maintenance provided

by the company which constructs gasification plants with internal combustion engine.

In Table 4, based on the availability of by-products (1100 tons/year) we

calculated the amount and the cost of necessary biomass for the operation of gasifiers

(40 % humidity): 829 tons/ year and 1,817 tons/year for the plant with the Stirling

engine and for the plant with internal combustion engine, respectively. In relation to

the re-use of thermal energy process of gasification plants, it is possible to dry a total

of 1,600 t/year of plates (13% of the processed products) for systems with Stirling

engine and about 700 tons/year of plates (6% of processed products) for gasifiers with

internal combustion engine.

Gasifier

Incomes (€/year) Costs (€/year)

Profit

(€/year)

Electricity Thermal

energy Total Biomass Managment Total

Gasifier with

internal combustion

engine

470,750 21,000 491,750 130,742 86,580 217,322 274,428

Gasifier with

Stirling engine 263,620 48,000 311,620 72,450 31,900 104,350 207,270

Table 3 – Profits and annual costs for the management of gasification plants.


Biomass Prices

(€/t)

Gasifier with internal

combustion engine Gasifier with Stirling engine

Quantity

(t)

Total costs

(€)

Quantity

(t)

Total costs

(t)

Wood saw dust 20 700 14,000 700 14,000

Bark (cortex) and residues 40 300 12,000 300 12,000

Unmarketable wood 50 100 5,000 100 5,000

Chips to be integrated 50 1,817 90,850 829 41,450

Diesel fuel 1235 7.2 8,892 - -

Total - 2,924 130,742 1,929 72,450

Table 4 – Costs of used biomass for each gasification plant.

At the end of the techno-economic feasibility assessment we concluded that

the remuneration and compensation time for the gasification plant with four

Stirling engines is of 5 years, after which the NPV starts to have a positive value

up to the amount of approximately 1.5 M €. For gasification plants with internal

combustion engines the recovery time is equal to 4 years and the NPV value after

20 years results in the range of 1.9 M €.

In case of no re-use of thermal energy the investment would be reimbursed

after 7 and 13 years for the plant with internal combustion engine and the one

with Stirling engines, respectively. This economic situation is caused by a

decrease in profits; the incomes due to the drying of wood panels were not

accounted and also due to a lower price of marketed electricity (Figure 1).

4 Conclusions

From the technical point of view the gasification plant with Stirling engines is

a more reliable energy system which is not subjected to strains due to the use of

syngas during its normal activity. On the other hand, the internal combustion

engine is significantly affected by the quality of applied fuel and all uncertainties

associated with revision times of these engines are still elevated. Moreover, the

re-use of thermal energy for drying processes of the plates could implement the

energy efficiency of the simultaneous production of electricity and heat in

small-scale plants, compared to the large cogeneration system where most part of

heat is dissipated.


Figure 1 – Cash flows of gasification plants in relation to profits from sale of electricity and

the re-use of thermal energy.

The analysis presented in this study could indicate that the investment costs in

both analyzed cases are extremely expensive for single companies. The

investment cost related to installed power units is greater in case of gasification

plant with four Stirling engines (€ 7,429/kWe) than that of gasifier with internal

combustion engine (€ 4,040/kWe). The economic analysis of the NPV

demonstrated that the installation of gasification plants with internal combustion

engine allows reimbursment of investment costs in shorter time compared to

gasifier with a Stirling engine. Nevertheless, the use of biomass gasification plants

for production of energy could reduce emission of carbon dioxide into the

atmosphere and implement carbon sequestration by distributing produced biochar

on agricultural land. Many issues must still be explored in terms of

techno-economic feasibility, local energy production policies and incentives based

on renewable sources as well as development of technologies that improve

efficiency of energy systems and the reduction of possible environmental impact.

References

[1] J. Richardson, T. Verwijst. Multiple benefits from sustainable bioenergy

systems. Biomass and Bioenergy 31 599-600 (2007).

-1500

-1000

-500

0

500

1000

1500

2000

2500

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

NP

V (

M€

)

Years

Combustion engine with heat utilization

Combustion engine without heatutilizationStirling engine with heat utilization

Stirling engine without heat utilization


[2] H. Chum, A. Faaij, J. Moreira, G. Berndes, P. Dhamija, H. Dong, B.

Gabrielle, A. Goss, W. Lucht, M. Mapako, O. Masera Cerutti, T. McIntyre, T.

Minowa, K. Pingoud. Bioenergy, in: O. Edenhofer, R. Pichs-Madruga, Y.

Sokona, K. Seyboth, P. Matschoss, S. Kadner, T. Zwickel, P. Eickemeier, G.

Hansen, S. Schlomer, C. Von Stechow (Eds.). IPCC Special Report on

Renewable Energy Sources and Climate Change Mitigation. Cambridge

University Press, Cambridge, United Kingdom and New York, NY, USA

(2011).

[3] IEA. Key world energy statistics 2011. International Energy Agency (IEA),

Paris, France (2011).

[4] H. Zhou, A.D. Jensen, P. Glarborg, A. Kavaliauskas. Formation and

reduction of nitric oxide in fixed-bed combustion of straw. Fuel 85, 705–716

(2006).

[5] S. Wongchanapai, H. Iwai, MSaito, H. Yoshida. Performance evaluation of

an integrated small-scale SOFC-biomass gasification power generation

system. Journal of Power Sources 216, 314-322 (2012).

[6] K. Openshaw. Biomass energy:employment generation and its contribution

to poverty alleviation. Biomass Bioenergy 34, 365–78 (2010).

[7] K. Yagi, T. Nakata. Economic analysis on small-scale forest biomass

gasification considering geographical resources distribution and technical

characteristics. Biomass and bioenergy 35, 2883-2892 (2011).

[8] ITABIA, Ministero dell’Ambiente e della Tutela del Territorio e del Mare. I

traguardi delle bioenergie in Italia. Rapporto (2008).

[9] Eurostat database. Available from: http://epp.eurostat.ec.europa.eu Accessed:

(October 2013).

[10] European Commission. Directive EC 28/2009 of the european parliament

and of the council on the promotion of the use of energy from renewable

sources and amending and subsequently repealing Directives 2001/77/EC

and 2003/30/EC. In: Official Journal. L 140. 05/06/2009. pp. 16-62 (2009).

[11] Italian Regulation. Decreto Ministeriale of 6 July 2012. Modalità di

incentivazione della produzione di energia elettrica da impianti alimentati da

fonti rinnovabili. diverse da quella solare fotovoltaica. con potenza non

inferiore a 1 kW. Ministry of Economic Development (2012).

[12] Italian Regulation. Decreto Ministeriale of 15 March 2012. Definizione e

quantificazione degli obietti regionali in material di fonti rinnovabili e

definizione della modalità di gestione dei casi di mancato raggiungimento

degli obiettivi da parte delle regioni e delle proviuncie autonome (c.d.

Burden Sharing). Ministry of Economic Development (2012).

[13] D.A. Laird. The charcoal vision: a win-win scenario for simultaneously

producing bioenergy, permanently sequestring carbon, while improving soil

and water quality. Agron. J. 100, 178-181 (2008).

[14] J. Lehman. Bio-energy in the black. Front Ecol. Environ. 5, 381-387.

[15] D. Bernocco, B. Bosio, E. Arato. Feasibility study of a spouted bed

gasification plant. Chemical engineering research and design 91, 843-855

(2013).

http://epp.eurostat.ec.europa.eu/


[16] H. Moritaa, F. Yoshibaa, N. Woudstrab, K. Hemmesc, H. Spliethoffb.

Feasibility study of wood biomass gasification/molten carbonate fuel cell

power system—comparative characterization of fuel cell and gas turbine

systems. Journal of Power Sources 138, 31-40 (2004).

[17] E. Bocci, M. Sisinni, M Moneti, L. Vecchione, A. Di Carlo, M. Villarini.

State of art of small scale biomass gasification power systems: a review of

the different typologies. Energy Procedia 45, 247-256 (2014).

[18] M. Uris, J.I. Linares, E. Arenas. Techno-economic feasibility assessment of a

biomass cogeneration plant based on an Organic Rankine Cycle. Renewable

Energy 66, 707-713 (2014)

[19] INFC database. Available from: http://www.sian.it/inventarioforestale.

Accessed: (March 2014).

[20] Foresta legno: la filiera del Friuli Venezia Giulia. Legno servizi (2010).

[21] Istat database. Available from: http://www.istat.it/prezzi/precon/rivalutazioni

Accessed: (March 2014).

[22] A. Colantoni, K. Boubaker, L. Longo, E. Allegrini, G. Menghini, B. Baciotti.

Optimizing the Energy Conversion Process: An Application to a Biomass

Gasifier-Stirling Engine Coupling System.. Applied Mathematical Sciences,

vol. 7, p. 6931-6934, ISSN: 1312-885X, doi: 10.12988/ams.2013.310567

(2013).

[23] A. Colantoni, E. Allegrini, K. Boubaker, L. Longo, S. Di Giacinto, P. Biondi.

New insights for renewable energy hybrid photovoltaic/wind installations in

Tunisia through a mathematical model. Energy Conversion and Management,

vol. 75, p. 398-401, ISSN: 0196-8904, doi: 10.1016/j.enconman.2013.06.023

(2013).

[24] A. Colantoni, E. Allegrini, F. Recanatesi, M. Romagnoli, P. Biondi, K.

Boubaker K. Mathematical Analysis of Gasification Process Using Boubaker

Polynomials Expansion Scheme. In: The 13th International Conference on

Computational Science and Its Applications. Lecture Notes in Computer

Science, vol. 7972, p. 288-298, ISBN: 978-3-642-39643-4, ISSN: 0302-9743,

Ho Chi Minh City, Vietnam, June 24-27, (2013), doi:

10.1007/978-3-642-39643-4_22.

[25] A. Colantoni, G. Menghini, M. Buccarella, S.R.S. Cividino S, M. Vello.

Economical analysis of SOFC system for power production. In:

Computational Science and Its Applications - ICCSA 2011. LECTURE

NOTES IN COMPUTER SCIENCE, vol. Springer, vol. IV, p. 270-276, ISBN:

978-3-642-21897-2, ISSN: 0302-9743, Spain, June 20-23, (2011), doi:

10.1700/978-3-642-21898-9.

[26] A. Colantoni, M. Cecchini, A. Marucci. Feasibility of the electric energy

production through gasification processes of biomass: technical and

economic aspects. In: Computational Science and Its Applications - ICCSA

2011 © Springer-Verlag Berlin Heidelberg 2011. vol. Part IV, p. 307-315,

ISBN: 978-3-642-21897-2, Spain, June 20-23, (2011), doi:

10.1007/978-3-642-21898-9_2.

http://www.istat.it/prezzi/precon/rivalutazioni


[27] D. Monarca, M. Cecchini, A. Colantoni. Plant for the production of chips and

pellet: technical and economic aspects of a case study in the central Italy. In:

Springer-Verlag Berlin Heidelberg 2011, In: Computational Science and Its

Applications. Santander (Spain), June 20-23, 2011. vol. Part IV, p. 296-306,

ISBN: 978-3-642-21897-2, Spain, June 20-23, (2011), doi:

10.1700/978-3-642-21898-9.

[28] K. Boubaker, A. Colantoni, E. Allegrini, L. Longo, S. Di Giacinto, P. Biondi.

Short-Term Perspectives for Hybrid Wind/Solar/Geothermal Renewable

Energy. International Journal of Renewable Energy Research, vol. 3, 2,

ISSN: 1309-0127 (2013).

[29] A. Marucci, D. Monarca, M. Cecchini, A. Colantoni, E. Allegrini, A.

Cappuccini. Use of semi-transparent photovoltaic films as shadowing

systems in mediterranean greenhouses.. In: 13th International Conference on

Computational Science and Its Applications. Lecture Notes in Computer

Science, vol. Volume 7972 LNCS, Issue PART 2, p. 231-241, ISBN:

978-364239642-7, ISSN: 0302-9743, Ho Chi Minh City, Vietnam, June

24-27, 2013, doi: 10.1007/978-3-642-39643-4_18 (2013).

Received: June 1, 2014

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