7/26/2019 chang2016-

1/6

Sensors andActuatorsB 225 (2016) 498503

Contents lists available at ScienceDirect

Sensors and Actuators B: Chemical

journa l homepage: www.elsevier .com/ locate /snb

Low temperature and large-scale growth ofZnO nanoneedle

arrays with enhanced optical and surface-enhanced

Raman scattering properties

Yu-Cheng Chang

Department of Materials Science and Engineering, FengChiaUniversity, Taichung, 40724, Taiwan

a r t i c l e i n f o

Article history:

Received 11 August 2015

Received in revised form

10 November 2015

Accepted 12 November 2015

Available online 24 November 2015

Keywords:

Nanoneedle

Aqueous chemical growth

Antireflection

Photocatalytic performance

Surface-enhanced Raman scattering

a b s t r a c t

Large-scale ZnO nanoneedlearrayshave been grown on four-inch silicon wafers with ZnO seed film by an

aqueous chemical growth method at a low growth temperature and short reaction time. The volumes of

1,3 diaminopropaneplay an important role in controlling the dimension and optical emission properties

ofZnO nanoneedle arrays, which exhibit a very prominent green emission and weak UV emission from

defect and band gaps in the cathodoluminescence spectrum, respectively. The ZnO nanoneedle arrays

with large alignment variations display broadband and omnidirectional antireflection properties from

the gradual index profile, and can provide a higher surface-to-volume ratio and stronger defect emission,

which results in a peak photocatalytic performance at a light irradiation of10W UV. The appropriate Ag

sputtering durations on the ZnO nanoneedle arrays have been optimized to yield the greatest surface-

enhanced Raman scattering effect in the rhodamine 6G molecule. The ZnO/Ag composite arrays provide

a facile, high enhancement, low detection limit and low cost fabrication, which shall be of significant

value for practical applications ofother SERS sensing systems.

2015 Elsevier B.V. All rights reserved.

1. Introduction

Zinc Oxide (ZnO) is one of most promising oxide materials,

which has attracted considerable interest due to its unique phys-

ical properties, such as its direct and wide band gap (3.37eV),

n-type semiconductor, largeexciton binding energy (60meV),high

electron mobility (100cm2 V1 s1), and piezoelectricity [13].

It is an important functional oxide, exhibiting high photore-

activity, near-UV emission, visible light transparency, biosafety,

and biocompatibility [4,5]. ZnO nanostructures have great poten-

tial for application in ultraviolet (UV) lasers [6,7], light-emitting

diodes [810], thin-film transistors [11,12], field emission (FE)

devices [13,14], solar cells [15], photocatalysis [4,16], and piezo-

nanogenerators [17,18].

ZnO nanostructures have be synthesized by various methods,

such as metal organic chemical vapor deposition [19], molecu-

lar beam epitaxy (MBE) [20], physical vapor deposition (PVD)

[21,22], pulsed laser deposition [23], and thermal evaporation

[24,25]. However, these methods generally require high temper-

ature, involve complicated equipment, and have a low yield [5].

Tel.: +886 424517250x5345; fax: +886 424510014.

E-mail address: ychang0127@gmail.com

The aqueous chemical growth (ACG) method is more attractive

attributed to its low cost, low temperature and feasibility for

industrial-scale fabrication [4,16,26]. Previous works on ACG pro-

cesses have been controlled to grow different morphologies by

adjusting reaction conditions, including pH [27,28], precursor con-

centrations [29], temperature [30], and surfactants [3133], etc.

Recently,ACGmethods have been developedfor fabricationof ZnO

nanostructures in various geometrical morphologies, including

nanowires [34,35], nanorods [29,36], nanotubes [37], nanopagodas

[4,26], nanoneedles [30], nanoplates [4,38], nanoparticles [39], and

nanoflowers [27], etc. Among them, ZnO nanoneedles can provide

for sharp curvatures of tips, which are expected to be of partic-

ular importance in field emissions [40], photocatalysis [41], and

optical properties [30,42]. However, there are fewer reports about

lowtemperature and large-scale growthof ZnOnanoneedle arrays

with high performance antireflective, photocatalytic, and surface-

enhanced Raman scattering properties.

The present work has synthesized well-aligned ZnO nanonee-

dlearraysby theACGmethodon four-inchsilicon waferswith ZnO

seed film. The appropriate volumes of 1,3-diaminopropane (DAP)

can be used to grow the highest aspect ratio of ZnO nanonee-

dle arrays at a relatively low growth temperature of 80 C for

1.5h. Hexamethylenetetramine plays an important role in inhibi-

ting theinfluenceofhigh pHvalueswith largedimensions. TheZnO

http://dx.doi.org/10.1016/j.snb.2015.11.053

0925-4005/2015 Elsevier B.V. All rights reserved.

http://localhost/var/www/apps/conversion/tmp/scratch_5/dx.doi.org/10.1016/j.snb.2015.11.053http://www.sciencedirect.com/science/journal/09254005http://www.elsevier.com/locate/snbmailto:ychang0127@gmail.comhttp://localhost/var/www/apps/conversion/tmp/scratch_5/dx.doi.org/10.1016/j.snb.2015.11.053http://localhost/var/www/apps/conversion/tmp/scratch_5/dx.doi.org/10.1016/j.snb.2015.11.053mailto:ychang0127@gmail.comhttp://crossmark.crossref.org/dialog/?doi=10.1016/j.snb.2015.11.053&domain=pdfhttp://www.elsevier.com/locate/snbhttp://www.sciencedirect.com/science/journal/09254005http://localhost/var/www/apps/conversion/tmp/scratch_5/dx.doi.org/10.1016/j.snb.2015.11.053

7/26/2019 chang2016-

2/6

Y.-C. Chang / Sensors andActuators B 225(2016) 498503 499

nanoneedle arraysexhibita very weak UVemissionandverystrong

green emission from a defect in the cathodoluminescence spec-

trum. The ZnO nanoneedle arrays have good geometric structures

forantireflectioncoatings,whichdisplaybroadbandreflectionsup-

pression from 4001950nm. ZnOnanoneedle arrays can provide a

higher surface-to-volume ratio and better stability against aggre-

gation, resulting in greater photocatalytic activity. In addition, ZnO

nanoneedle arrays have good geometric structures for deposition

three-dimensional Ag nanoparticles, which lead to high perfor-

mance surface-enhanced Raman scattering (SERS) detection. The

present work can provide insight into further structural design for

nanostructured optical and SERS applications.

2. Experimental

2.1. Synthesis

A Si (001) wafer was cleaned ultrasonically for 10min in

ethanol.A thin filmof zinc acetate wasthencoatedon thesubstrate

byspinninga layer of solutionof 5mM zincacetate dihydrate (98%

Aldrich) in ethanol and repeating for ten times. 510nm thick ZnO

seed film was produced after annealing at 300 C in air for 20min

[4,43]. The ZnO nanoneedle arrays were grown by an ACG methodin 100mLof aqueous solution containing 10mM equimolar zinc

nitrate hexahydrate (98% Aldrich) and hexamethylenetetramine

(99% Aldrich) (HMTA), with the addition of different volumes of

1,3-diaminopropane (98%, Alfa Aesar) (DAP). The substrate with

ZnO seed film was pasted at the side of a sealed bottle containing

the above solution and heated to about T= 80 C for1.5h.

2.2. Characterization

The morphology of nanostructures was examined with a field

emission scanning electron microscope (FESEM) using a JEOL

JSM-6500F SEM operating at 10kV accelerating voltage. A JEOL-

2010 transmission electron microscope (TEM) operating at 200 kV

was used to examine the microstructures. The crystalline phaseof the ZnO nanostructures was determined using the X-ray

powder diffraction method (Shimadzu XRD-6000, CuK1 radia-

tion (= 0.1505nm)). The cathodoluminescence (CL) spectra were

acquired with an electron probe microanalyzer (Shimadzu EPMA-

1500) attached to a SEM. CL spectra were accumulated in a single

shotmodewithinanexposurerateof 1nm/s.All theCL spectrawere

taken at room temperature. The reflection spectra were obtained

with a Hitachi Model U-4100spectrophotometer. The degradation

of methyleneblue solution wasused to evaluate thephotocatalytic

activity of ZnO nanoneedle arrays. The methylene blue solutions

were exposed to a 10W UV lamp. For the photocatalytic activity

evaluation, the concentration of photodegraded methylene blue

was recorded by a Hitachi U-2900 UVvis spectroscopy. Ion sput-

tering (EMITECH KSC7620) was used to deposit Ag nanoparticles

on the surface of ZnO nanoneedle arrays. The Raman spectra were

performed by Confocal Raman Microscope (HORIBA, LabRAM HR)

at room temperature in thebackscattering configuration. The light

source was a He-Ne laser emitting a wavelength of 632.8nm.

3. Results and discussion

3.1. Evaluation of ZnO nanoneedle arrays

Fig. 1ad show the cross-sectional SEM images depicting the

vertical ZnO nanoneedle arrays grown from equimolar (10mM)

zinc nitrate and HMTA, and the different volumes of DAP solu-

tion by an ACG method at the growth temperature of 80 C

for 1.5h. The volumes of DAP were 0.25, 0.5, 0.75, and 1mL,

Fig.1. Thecross-sectionalSEM images of theZnO nanoneedlearraysweregrownon

the silicon substrates with ZnOseed filmat differentvolumes of DAP. The volumes

ofDAPare(a) 0.25,(b) 0.5, (c)0.75,and(d) 1mL,respectively.(e) Theaveragelength

ofZnOnanoneedle arrays as a function of thevolumes of DAP.

respectively. The lengths of ZnO nanoneedles gradually increased

with an increase in DAP volumes, as shown in Fig. 1e. The aver-

age lengths of ZnOnanoneedles were 0.36, 1.29, 1.99, and5.07m,

respectively. Andthemediumdiameters of ZnOnanoneedles were

82.39.4,55.510.4, 53.916.7,and66.514.1nm, respectively.

In addition, the aspect ratios (length /diameter) of ZnO nanonee-

dleswere4.4,23.2,36.9,and76.2, respectively.TheZnOnanoneedle

arrayshad thelongest lengthand highestaspect ratiosat a DAPvol-ume of 1mL. In general, the solubility of ZnO in an alkali solution

was found to increase with an increase in the alkali concentration

and temperature [44]. The pH value turned from 6.94 to 11.45 by

the addition of DAP (1mL) in the growth solution. If the volumes

of DAP are higher than 1mL, the solution becomes too alkaline

to restrain the growth of ZnO nanoneedle arrays. The excessive

amount of DAP not only influenced the growth of ZnO nanonee-

dle arrays, but also etched the ZnO seed film. On the other hand,

appropriate volumes of DAP lead to the growth of ZnO nanoneedle

arrays with long length and high aspect ratio.

The seed film has been found to be beneficial for fabricating

ZnO nanowire or nanorod arrays with a wafer-scale production

by the ACG method with a neutral pH value [45]. And in order to

ensure that the alkaline condition would not influence the growththeuniformityof ZnOnanoneedlearraysfora four-inchwaferscale,

highconcentrations(20mM)ofzinc acetatedihydrate were used to

prepare a thicker ZnO seed film for the growth of ZnO nanoneedle

arrays. Inaddition,a bigger reactionchamberanda copiousreaction

solution were neededto grow aligned andregular ZnOnanoneedle

arrays over a large area. Fig. 2a shows that ZnO nanoneedle arrays

successfully covered a four-inch Si wafer. SEM images taken from

several four-inch samples revealed that entirewafer canbe grown

with highly uniform andaligned ZnOnanoneedle arrays, as shown

in Figs. 2b and c. The medium diameters and average lengths of

ZnO nanoneedles were 71.216.8nm and 4.76m, respectively.

In addition, the average density of ZnO nanoneedle arrays was

4.3109 cm2. AndthedimensionsofZnOnanoneedlearrayswere

notchangedby anincrease insizeofthe reactionchamberor adding

7/26/2019 chang2016-

3/6

500 Y.-C. Chang / Sensors andActuators B 225 (2016) 498503

Fig. 2. (a) A photography and (b-c) SEM images of ZnO nanoneedle arrays were

grown on a four-inch silicon wafer at different locations, magnifications, and tile

angles(0 or20).(d) Theplan-viewSEMimageof ZnOnanoneedle arrayswasgrown

from 10mM zinc nitrate and 1 mLDAPon the silicon substrate with ZnOseed film.

Fig. 3. (a)TEM image of a ZnO nanoneedle arraysin Fig. 1(d). (b)HRTEMimageand

corresponding SAED pattern confirming the single crystallinity of a ZnO nanonee-

dle in (a). (c) XRD spectrum of ZnO nanoneedle arrays was grown on the silicon

substrates with ZnOseed film.

to theamountofreactionsolution.Fig.2d showsthat theplan-view

SEMimage depicting theZnOnanoneedle arrayswere grown from

10mM zinc nitrate and 1mLDAP on the silicon substrate withZnO

seed film. The medium diameters and density of ZnO nanoneedles

were 329.8130.4nm and 3.7108 cm2, respectively. When the

reaction solution wasonly zinc nitrate andDAP, thedimensions of

ZnOnanoneedle arrays appeared non-uniform and aggregate. This

phenomenon is attributed to HMTA acting as both a long chain

polymer and a nonpolar chelating agent at low reaction temper-

atures. HMTA is preferentially attached to the nonpolar facets ofthe ZnO crystal, in turn restraining the access of Zn2+ ions to them

and leaving only the polar [00 1] face for epitaxial growth [46,47].

Therefore, HMTA acts a shape-inducing polymer surfactant to con-

trol the dimension of ZnO nanoneedle arrays.

Fig. 3a shows a TEM image of a ZnO nanoneedle (in Fig. 1d)

with a length of 1136nm and tip diameter of about 8nm. The

high-resolution TEM image taken from part of an individual ZnO

nanoneedle and the corresponding SAED pattern is shown Fig. 3b

andthe inset,respectively, whichalso shows thesame [01 0] zone-

axis SAED pattern. Both the HRTEM image and diffraction pattern

indicate that the ZnO nanoneedle is single-crystalline and grown

in the [00 1] direction. The crystal perfection of the ZnO nanonee-

dle arrays was also investigated by X-ray powder diffraction. The

XRD pattern of nanoneedles grown on the ZnO seed film is shown

Fig. 4. Cathodoluminescencespectra of ZnO nanoneedle arrays weregrown on the

silicon substrates with ZnOseed filmat thedifferent volumes of DAP. The volumes

ofDAP were0.25, 0.5, 0.75,and 1mL, respectively.

in Fig. 3c. A strong and sharp diffraction peak corresponding to

the (00 2) crystal plane of ZnO indicates that the preferred growth

direction of the ZnO nanoneedles is in the [00 1].

3.2. Optical properties of ZnO nanoneedle arrays

To investigate the optical properties of ZnO nanoneedle arrays,

cathodoluminescence (CL) spectroscopy was employed. All the CL

spectra were takenat room temperature.Fig. 4 shows that CL spec-

tra of ZnO nanoneedle arrays were grown in different volumes of

DAP. The volumes of DAP were 0.25, 0.5, 0.75, and 1mL, respec-

tively. From 0.25 to 0.75mL, the intensityof theband gapemission

did not change with an increase in the volume of DAP. However,

the intensity of green emission had a tendency to increase with an

increase in thevolume ofDAP. Themaximumgreenemissionpeaks

were 556, 560, 565, and 573 nm, respectively. This result is accor-

dant with the currently accepted model that the green emission

arises from the recombination between holes trapped at the sur-

face defect andelectrons trapped at theoxygenvacancy [30]. With

an increase in the volumes of DAP, the maximum peaks of greenemission evinced a red shift. The red shift shall be attributed to

thereverse quantum confinement effectarising from theincreased

lengths of nanoneedles. In some previousworks,the energyshift of

nanostructures with dimensions far beyond thequantum confine-

ment regime is ascribed to the surface effect due to the increased

surface-to-volume ratio [4,16,36,48]. The ZnO nanoneedle arrays

exhibit the strongest UV and defect emission at DAP volumes of

1 mL. The surface oxygendeficiencies are electron capture centers,

which can be used to enhance the photocatalytic activity of ZnO

nanostructuresbyreducingtherecombinationrateof electronsand

holes [16,49]. The significant defect emission property and high

surface-to-volume ratio of ZnO nanoneedles shall be beneficial to

photocatalytic applications.

ZnO nanostructures have been very suitable for using efficientantireflection coating layers, which are attributed to their high

transparency, appropriative refractive index, and feasible fabrica-

tionprocess [42,50]. Herein, thespecular reflectancewas measured

todeterminethe antireflectiveproperties ofZnOnanoneedlearrays

for wavelength of 3501900nm, as shown in Fig. 5. The incident

angle was fixed at 5 relative to normal samples in the measure-

ment. When compared the ZnO seed film and ZnO nanoneedle

arrays at different volumes of DAP revealed the importance of

morphology on antireflection coating layer performance. The ZnO

nanoneedle arrays (1mLDAP) displayed the lowest reflectance in

the broad range of wavelength. The morphology of ZnO nanonee-

dle arrays exhibited sharp tips and long lengths, which denotes

a gradual decrease in the refractive index from the surface of Si

substrate to the ambient air, resulting in the best antireflection

7/26/2019 chang2016-

4/6

Y.-C. Chang / Sensors andActuators B 225(2016) 498503 501

Fig. 5. The reflection spectra of the different ZnO nanostructures were grown on

the silicon substrates.

properties. Broadband antireflection characteristics are generally

correlated with a graded refractive index profile [51]. In addition,

the small bumps at 890nm on the curve come from the detector

change during the data collection of the equipment. These find-

ings show that ZnO nanoneedle arrays with the broadband and

omnidirectional antireflectioncoatings can greatly benefittheper-

formance of optical and electric devices, such as light-emitting

diodes and photovoltaic cells.

3.3. Photocatalytic properties of ZnO nanoneedle arrays

Methylene blue (MB) is selected as a representative organic

pollutant to evaluate the photocatalytic performance of the ZnO

nanoneedle arrays under 10W UV light irradiation. The ZnO

nanoneedle arrays were grown on a 1cm2cm silicon substrate

as a photocatalytic sample. The photocatalytic degradation of MB

solution under UV light irradiation was conducted to evaluate the

photocatalytic activity for ZnO nanoneedle arrays grown by the

different volumes of DAP, as shown in Fig. 6a. The decrease in

absorbance at a wavelength of 664nm was observed with the

increase of irradiation time andDAPvolumes. TheZnOnanoneedlearrays (at 1mLDAP) exhibited the highest photocatalytic activ-

ity in the decomposition of MB. This phenomenon coincides with

the highest aspect ratio and strongest defect emission of ZnO

nanoneedle arrays (at 1 mLDAP), and provides direct evidence in

demonstrating that a strongdefect emission anda high surface-to-

volume ratio are beneficial to enhance the photocatalytic activity.

Fig. 6b shows the photocatalytic efficiency of the different ZnO

nanoneedle arrays, whichwere grownin thereactionsolutionwith

(Fig. 1d) or without HMTA (Fig. 2d) by an ACG method. The ZnO

nanoneedle arrays (with HMTA) exhibit a high surface-to-volume

ratio (smalldimension andhigh density), resulting ina higherpho-

tocatalytic efficiency.

In order to confirm the stability and reusability of ZnO

nanoneedle arrays, cyclic experiments were used to evaluate thephotodegradation efficiency of MB. The MB solution with the ZnO

nanoneedle arrays (1mL) on a silicon substrate was illumined

under UV light for 3h and rinsed with de-ionized water to remove

the residual MB, and dried under an N2 purge. This substrate was

then immersed into a fresh MB solution with the same concentra-

tionfor anothercycleof photodecomposition.Over tencycles, these

experiments show that the degradation rate was almost constant,

confirmingthat ZnOnanoneedlearraysareinherentlystableduring

prolonged photocatalytic reactions, as shown in Fig. 6c. After ten

cycles, theZnOnanoneedle arraysmaintained a high reusability of

95.6%. SEM examination of this substrate after ten cycles suggests

that the nanoneedles appearance and density will not undergo

any change. Therefore, ZnO nanoneedle arrays are expected to

have a long service life as photocatalysts with high efficiency and

Fig. 6. The MB normalization concentrations (from the optical absorbance mea-

surements at 664nm) in the solution with ZnOnanoneedle arrays substrates were

grown by (a) the different volumes of DAP and (b) with or without HMTA versus

the irradiationtime of UV light, respectively. (c)Themaximumabsorptionintensity

at 664nm as function of photodecompositioncycles forthe ZnOnanoneedle arrays

(1mLDAP) under UV light irradiation for 3h at room temperature.

durability. Furthermore, ZnO nanoneedle arrays that are grown

on a silicon substrate simplify the recycling process, making ZnO

nanoneedle arrays steady and economical photocatalysts.

3.4. Surface-enhanced Raman scattering properties of ZnO

nanoneedle arrays

Recently, ZnO has received special attention due to its

excellent performance for supporting chemical enhancement of

surface-enhancedRaman scattering (SERS) substrates [52,53]. ZnO

nanoneedle arrays exhibit good geometric structures for deposit-

ing Ag nanoparticles, with better stability against aggregation for

the applications of SERS substrates. Rhodamine 6G (R6G) was

chosen as the probe molecule owing to its well-established vibra-

tional features. [54,55]. Figs. 7 a-e show the SERS spectra of R6G

solution (1106 M) dispersed on the ZnO nanoneedle arrays

with different Ag-sputtering durations. The Ag-sputtering dura-

tions were 30, 60, 90, 120, and 150s, respectively. The strong and

7/26/2019 chang2016-

5/6

502 Y.-C. Chang / Sensors andActuators B 225 (2016) 498503

Fig. 7. SERS spectra of R6G (1106 M) absorbed on the ZnO nanoneedle arrays

withdifferent Ag-sputteringdurations. TheAg-sputteringdurations were(a) 30, (b)

60, (c) 90, (d) 120, and (e) 150 s, respectively.

Fig. 8. (a) The SERS signals at 1657cm1 versus the Si or ZnO nanoneedle arrays

were depositedwith differentAg-sputteringdurations. (b) TheSERS signals of ZnO

nanoneedle arrays with an Ag-sputtering duration of 60 s at 1657 cm1 versus the

differentconcentrations of R6G.

medium-strong Raman bands at 1365, 1514, 1578, and 1657 cm1

arise from the totally symmetric modes of in-plane C C stretching

vibrations [55]. An obvious trend shows that the intensity of the

Raman signal at 1657cm1 decreased strongly with an increase in

theAg-sputteringdurationsfrom60150s. ZnOnanoneedlearrays

with Ag-sputtering duration of 60s exhibited the maximum SERS

signals. The change of SERS intensity is attributed to the differ-

ent coverage and sizes of Ag nanoparticles on the ZnO nanoneedle

arrays obtained from different Ag-sputtering durations. When the

Ag-sputtering durations were longer than 60 s, the Ag nanoparti-

clesappearedtheaggregationandreductionthe SERSsignals.These

results confirm that theAg-sputtering durations play a crucial role

in determining the coverage and sizes of Ag nanoparticles on the

ZnO nanoneedle arrayswith highest SERS enhancement.

Fig. 8a shows the Raman intensity at 1657cm1 obtained from

the different Ag-sputtering durations on the Si or ZnO nanonee-

dle arrays, respectively. It is clearly observed that the signals of

ZnO nanoneedle arrays with different Ag-sputtering durations are

much higher than Si with different Ag-sputtering durations. The

Ramanintensityof Si isdecreasedwithan increase inAg-sputtering

durations. This phenomenon is attributed to the occurrence of

aggregation with an Ag-sputtering duration longer than 30s. In

addition, the SERS enhancement factor (EF) of the ZnO nanonee-

dle arrays with Ag-sputtering durations of 30s and 60s is about

14.6 and 67.2 times greater than Si with an Ag-sputtering dura-

tion of 30s. The different Ag-sputtering durations on the Si and

ZnOnanoneedle arraysfor thedetection of R6G(1657 cm1)canbe

statistically evaluated in Table 1. The SERS activity of the ZnO/Ag

composite arrays is higher than only Ag nanoparticles, which can

be explained by the electromagnetic enhancement mechanism as

a result of surface plasmon resonance excitation of Ag nanopar-

ticles, and chemical enhancement effects of ZnO [52]. To further

reveal the good SERS enhancement effects of the ZnO nanoneedle

arrayswithAg sputtering for60 s,theRamanintensityat1657cm1

is obtained from the different concentration of R6G, as shown in

Fig. 8b. The SERS signals at1657cm1 are indeed found to increase

with an increase in the concentration of R6G. The peak remains

clearly observable in the R6G solution with concentrations as low

as109 M. This indicates that theZnO/Agcompositearraysas SERS

substrates provide strong Raman signals of R6G. The fabrication of

ZnO/Ag composite arrays is facile, low cost, highly enhanced, and

with a low detection limit (109 M), which shall be advantageous

in applications for other SERS sensing systems.

4. Conclusions

VerticallyalignedZnO nanoneedlearrayshavebeen synthesized

on a Si wafer with ZnO seed film using a facile ACG method with

a low reaction temperature and a short reaction time. The dimen-

sions andoptical emissionproperties of ZnOnanoneedle arraysare

effectively controlled by the volumes of DAP. The ZnO nanonee-

dle arrays exhibit very strong and broad green emission from

defectin thecathodoluminescence spectrum.The sharp tips of ZnO

nanoneedlearraysprovideexcellent impedancematchingbetween

Si and air through a gradual reduction of the effective refractive

index away from the surface, resulting in superior antireflection

property over a greater range of wavelength. ZnO nanoneedlearrays have shown a structure-induced enhancement of photo-

catalytic performance by higher surface-to-volume ratio, which

exhibits a muchbetter photocatalyticproperty for thephotodegra-

dation of MB in 10W UV light irradiation. The ZnO nanoneedle

arrays withappropriate Ag-sputtering durationhaveexhibited the

highest SERS activity for R6G detection, suggesting their great

potentialas a convenientSERSsubstrateforbiosensorapplications.

Table 1

The SERS singles ofR6G (1657cm1) obtained on theSi andZnOnanoneedle arrays with thedifferent Ag-sputtering durations.

Ag-sputtering durations 30 s 60 s 90 s 120s 150s

SERS enhancement (Si) 50378

SERS enhancement (ZnO nanoneedle arrays) 7320846 338203814 301505138 178803526 4950975

7/26/2019 chang2016-

6/6

http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0550http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0545http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0545http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0545http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0545http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0545http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0545http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0545http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0545http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0545http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0545http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0545http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0545http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0545http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0545http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0545http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0545http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0545http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0545http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0545http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0545http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0545http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0545http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0545http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0545http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0545http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0545http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0545http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0545http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0540http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0535http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0530http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0530http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0530http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0530http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0530http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0530http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0530http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0530http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0530http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0530http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0530http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0530http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0530http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0530http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0530http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0530http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0530http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0530http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0530http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0530http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0525http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0520http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0520http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0520http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0520http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0520http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0520http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0520http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0520http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0520http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0520http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0520http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0520http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0520http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0520http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0520http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0520http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0520http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0520http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0520http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0520http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0520http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0520http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0520http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0520http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0520http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0520http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0520http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0520http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0515http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0510http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0505http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0500http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0495http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0495http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0495http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0495http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0495http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0495http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0495http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0495http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0495http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0495http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0495http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0495http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0495http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0495http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0495http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0495http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0495http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0495http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0490http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0490http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0490http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0490http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0490http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0490http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0490http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0490http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0490http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0490http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0490http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0490http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0490http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0490http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0490http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0490http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0485http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0485http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0485http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0485http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0485http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0485http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0485http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0485http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0485http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0485http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0485http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0485http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0485http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0485http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0485http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0485http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0485http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0485http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0485http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0485http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0485http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0485http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0485http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0485http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0485http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0485http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0480http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0475http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0475http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0475http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0475http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0475http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0475http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0475http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0475http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0475http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0475http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0475http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0475http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0475http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0475http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0475http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0475http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0475http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0475http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0475http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0475http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0475http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0475http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0475http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0475http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0475http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0475http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0470http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0465http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0460http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0455http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0450http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0450http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0450http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0450http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0450http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0450http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0450http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0450http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0450http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0450http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0450http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0450http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0450http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0450http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0450http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0450http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0450http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0450http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0450http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0450http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0450http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0445http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0440http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0440http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0440http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0440http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0440http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0440http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0440http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0440http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0440http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0440http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0440http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0440http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0440http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0440http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0440http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0440http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0440http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0440http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0440http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0440http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0440http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0440http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0440http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0440http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0440http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0440http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0435http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0435http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0435http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0435http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0435http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0435http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0435http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0435http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0435http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0435http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0435http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0435http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0435http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0435http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0435http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0435http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0435http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0435http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0435http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0435http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0435http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0435http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0435http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0435http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0430http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0425http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0425http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0425http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0425http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0425http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0425http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0425http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0425http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0425http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0425http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0425http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0425http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0425http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0425http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0425http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0425http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0425http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0425http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0425http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0425http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0425http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0425http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0420http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0420http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0420http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0420http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0420http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0420http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0420http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0420http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0420http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0420http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0420http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0420http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0420http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0420http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0420http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0420http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0420http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0420http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0420http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0415http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0410http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0405http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0400http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0400http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0400http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0400http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0400http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0400http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0400http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0400http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0400http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0400http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0400http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0400http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0400http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0400http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0400http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0400http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0400http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0400http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0395http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0395http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0395http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0395http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0395http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0395http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0395http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0395http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0395http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0395http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0395http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0395http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0395http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0395http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0395http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0395http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0395http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0390http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0385http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0380http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0380http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0380http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0380http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0380http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0380http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0380http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0380http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0380http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0380http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0380http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0380http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0380http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0380http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0380http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0380http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0380http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0380http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0380http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0380http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0380http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0380http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0380http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0380http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0380http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0380http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0380http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0375http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0370http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0365http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0365http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0365http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0365http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0365http://refhub.elsevier.com/S0925-4005(15)30638-9/sbref0365http://refhub.elsevier.c