Study of recycled plastic aluminates relative to environmental physical stresses as barrier material

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Study of recycled plastic aluminates relative to environmental
physical stresses as barrier material
1,2, 2,3 1,4 1,5
Delia B. Senoro, * Albert A. Grino, Jr., Donamel M. Saiyari and Blessie A. Basilia
1
Environmental Engineering Graduate Program
Mapua Institute of Technology
Manila 1002, Philippines
2
Sustainable Development Research Office
Mapua Institute of Technology
Manila 1002, Philippines
3
Department of Mathematics
Mapua Institute of Technology
Manila 1002, Philippines
4
Department of Civil Engineering
Adamson University
Manila 1000, Philippines
5
Material Science Division
Industrial Technology Development Institute
Taguig 1631, Philippines
Key Words: Barrier, environmental stresses, plastic aluminates, recycling
*Corresponding author
Email: dbsenoro@mapua.edu.ph; drsenoro@gmail.com
ABSTRACT
INTRODUCTION
This study investigated the capability of recycled plastic aluminates (RPAs) against environ-
mental stresses. These environmental physical stresses of concern are: water, leachate and gas vapour
permeation; thermal conductivity, and environmental stress cracking (ESC). RPAs possess properties
potential as environmental protection material. The permeation properties with respect to water, gas,
leachate, as well as thermal insulation and ESC, that would aid in concluding that RPAs as a barrier
material has not been investigated. Hence, this study was carried out with the objective to investigate
the above mentioned properties. Flexible plastic aluminium laminate trimmings (FPALTs) and vari-
able weight percentages of organoclay (OC) were formulated, processed, characterized and ex-
amined. Methods of examination followed those procedures of American Society for Testing and
Materials and International Standards Organization. Fourier Transformed Infrared (FTIR) approach
was used for the investigation of ESC resistance. Results showed that impregnation of OC improved
the water vapour permeability and thermal insulation property. RPA with 10% OC is the best per-
forming RPAs for thermal insulation. All RPAs batches are considered water and leachate vapour
barrier, gas vapour retarder, and moderate thermal insulator. FTIR showed that all pristine RPAs, i.e.,
regardless of thickness and FPALT particle size, are ESC resistant. With the above mentioned results
of the study, it was concluded that RPAs are indeed a barrier and moderate insulator material that
would have potential economic value for public consumption. However, it is recommended to con-
duct further investigation to fully understand the effects of OC concentration in reduced permeability
of RPAs. Also, detailed study on economic related analysis and risk assessment is necessary to ensure
environmental and public health safety. .
Global production of plastic continues to rise by
an average of almost 10% every year [1]. This may
cause problems in the environment and public health if
Sustain. Environ. Res., 22(6), 387-394 (2012)
387
not given the necessary recycling study and related
mitigation initiatives. Due to increasing demand of
plastics that is forecasted to remain in the market even
for 50 yr or beyond, recycling of plastic wastes has
received increasing attention all over the world [2-4].

Fig. 1. FPALs produced as recycled plastic aluminates.
Fig. 2a. SEM result of pristine RPA, magnification: 2000x.
Fig. 2b. SEM result of RPA impregnated with OC,
magnification: 2000x.
Batch 3
Batch 4
Batch 5
Fig. 3. SEM of various RPAs, magnification = 2000x.
388
Senoro et al., Sustain. Environ. Res., 22(6), 387-394 (2012)
In the Philippines, the Metro Manila Solid Waste
Management Project identified that among the sampled
municipal solid waste, 50% were biodegradable, 45%
were considered as recyclables, 4% were inert mate-
rials and 1% were considered hazardous or special
wastes, of which 24.7% were plastics [5] of which
17% was identified as flexible plastics [6]. Further and
according to the Flexible plastic aluminium laminate
trimming (FPALT) generators in the Philippines, 4-6 t
of FPALTs were produced every plant per month since
2004. There are about 20 FPALT generators in the
Philippines in which 5 are major generators. The
Philippines has having problems on the solid wastes
management especially plastics as these are recalci-
trant and hence inert that lead to the accumulation in
the environment. The country lacks sanitary landfill
and not embracing the incineration technology, which
could greatly help in waste volume reduction. Hence,
it is important to recycle FPALTs to reduce the amount
of solid waste generated [6]. Utilization of FPALTs
would not only aid in giving solution to solid waste
management problem but help boost local economy
by providing job opportunities. Simple physico-me-
chanical recycling process was used in 2005 to recycle
FPALTs which produced recycled plastic aluminates
(RPAs, Fig. 1). FPALT is an industry multilayer plastic
waste that contains metalized aluminum. Grounded
FPALTs were impregnated with organoclay (OC) of
variable weight percentages to produce RPAs [6]. OC
is a three-layered silicate of montmorillonite nanosized
particles extracted from calcium bentonite deposit of
Albay, Philippines [7]. This OC is similar to what has
been described in the work of Shih et al. [8]. Initial
investigation of its physical, chemical, mechanical
properties, optimum thickness, surface morphology
[3,6], and structural integrity [3,5] was carried out.
Previous studies of RPA showed that surface morphol-
ogy of pristine RPA (100% FPALTs) is homogenous
(Fig. 2a). However, other RPA batches impregnated
with OC showed uneven distribution of OC and
aluminum flakes (Fig. 3). These findings will be ad-
dressed in RPA development process. Further, it is
emphasized that focus of this paper is not on the com-
position of OC. In the past studies, the water vapour,
gas vapour and leachate permeability, thermal insula-
tion capability, and environmental stress cracking
resistance (ESCR) were not examined. These material
properties are called physico-mechanical which is
significant in identifying whether RPAs are indeed
barrier materials. Hence, this study was carried out
with the objective to investigate the water, gas, and
leachate vapour transmission rate, thermal insulation,
and ESCR capability as barrier material. This study
will validate if RPAs are indeed a barrier material.
There is a need to investigate these properties as
moisture addition and leachate recirculation practices
are popular in landfill system [9] where one of the
potential application areas of RPA is the landfill liner.
In the Philippines, one of the typical materials
.
FPAL
RPA

Fig. 4. RPA specimen before and after ESCR test.
Senoro et al., Sustain. Environ. Res., 22(6), 387-394 (2012)
389
before
after
(a)
(b)
two specimens (m), Q and Q are the electric signal,
12
T is the gradient temperature (K) and S is the calibra-
cal
tion factor.
Statistical method was performed with the Analy-
sis of Variance procedure using Matlab R2007b soft-
ware. Dunnett's procedure (P < 0.05) was used to de-
tect differences between each treatment mean and the
control. On the other hand, Friedman test was used as
a non-parametric test for the data which do not follow
the normal distribution.
Another set of RPAs (all pristine, 100% FPALTs)
were produced using the same recycling process;
formulating with variable thickness and different
FPALT particle size produced six batches. This type
of sample batch was prepared to determine if thickness
and particle size affect the ESCR capability of RPA.
These six batches of RPA specimen were then condi-
tioned for ESCR analysis (Fig. 4) in accordance to
ASTM D1693 [17]. The equipment used for this proc-
ess was Yih Der Water Bath ESC resistance apparatus
with temperature set at 50 °C. The ESCR test was
carried out by D&L Industries, Canlubang, Laguna,
Philippines. FTIR test followed after ESCR test using
the attenuated total reflectance by Perkin-Elmer Spec-
trum 100 FTIR spectrometer. This was conducted in a
controlled room temperature and relative humidity.
.
.
MATERIALS AND METHODS
(1)
where x and x are the change in thickness of the
12
ë =
S QQ( X - Q)
cal 1 2 2 1
T(X - Q )
12
used as barrier on geotechnical application is high
density polyethylene as it offers good weathering
resistance [10]. This property relates to endurance and
survivability which corresponds to the ESCR of a
material. Hence, it is significant to investigate how
RPAs respond with vapour and thermal permeation.
cause premature failure through developing a leak.
Fourier Transformed Infrared (FTIR) could provide
evidence in this study on ESCR capability as the pres-
ence of carbonyl group in the material indicates
polymer degradation. Carbonyl groups are postulated
to be the main light-absorbing species responsible for
the photochemical induced degradation reactions of
polymers [11]. This act is the main parameter of stress
in photo degradation in combination with the effects
of temperature, moisture and oxygen. Therefore, the
conduct of ESCR, FTIR, water vapor transmission rate
(WVTR), gas vapor transmission rate (GVTR), leach-
ate vapor transmission rate (LVTR), and thermal con-
ductivity ( ) test for a material is necessary.
ESCR test is illustrated through evidence of crack and
degradation by the presence of carbonyl bands that
.
RPAs were reproduced following a simple
physico-mechanical recycling process, i.e., shredding,
weighing, melt intercalation, compression molding,
and formulation as described in Senoro and Peralta [6].
Formulation of five batches were as follows: (1) 100%
FPALs; (2) 99% FPALs with 1% OC; (3) 97% FPALs
with 3% OC; (4) 95% FPALs with 5% OC; and (5)
90% FPALs with 10% OC. Investigation on WVTR
and GVTR as well as thermal insulation was per-
formed in reproduced RPAs. Test method for the in-
vestigation of WVTR, and LVTR was in accordance
with ASTME96 [12] using the test equipment model
PERME W3/030, and GVTR followed the ASTM
D1434 [13] with test equipment model PERME®
VAC-V1. The WVTR and LVTR tests were performed
under controlled relative humidity of 90% and a
temperature of 38 °C. The GVTR test was done at
23 °C and relative humidity of 0%. The gases used in
GVTR test were O , N , CO and air. Water, leachate,
22 2
and gas permeability were calculated using equations
described in the book of Koerner [14]. WVTR, LVTR,
and GVTR tests were conducted at Jinan, China. The
test method for the investigation of insulating property
was in accordance with ASTM C518 [15] and ISO
8301 [16] and conducted in London. Fox 50 apparatus
was employed for calculating thermal conductivity
( ) value using Eq. 1 below. .

RESULTS AND DISCUSSION
The following sub-sections describe the physico-
mechanical capability of RPAs relative to WVTR,
LVTR, GVTR, thermal insulation, and ESCR using
FTIR approach.
1. Permeance of WVTR and LVTR
The values of WVTR ranged from 1.12 to 4.65 g
-2 -1
m d as shown in Table 1a. These values are compara-
ble to other thermoplastic materials such as PET =
3.28, polystyrene = 5.18, LDPE = 7.9 [17] and PVC =
-2 -1
4.4 g m d [14]. ASTM requires that the permeance
rating for water vapour retarder should be 1 perm or
less. This shows that the impregnation of OC improves
the impermeability property of RPA; however, limited
to 3 wt%. This result is similar to the work of Yano et
al. [18] and Park et al. [19] which showed that water
vapour permeability values of polymer/clay nanocom-
posite decreased with increase in clay content or in-
.
.
Table 1a. WVTR and Permeance of RPAs, thickness = 3 mm
Table 1b. Gas Permeability of RPAs, thickness = 3 mm
Table 1c. Rate of burning and flammability characteristics of RPAs, thickness = 3 mm
RPA Batch No.
1
2
3
4
5
RPA Formulation
100% FPALTs & 0% OC
99% FPALTs & 1% OC
97% FPALTs & 3% OC
95% FPALTs & 5% OC
90% FPALTs & 10% OC
WVT
2.21
1.25
1.12
4.65
2.03
-2 -1
R (g m d )
Permeance (Perms)
0.071
0.040
0.036
0.150
0.065
RPA Batch No.
1
2
3
4
5
-1
Rate of Burning (mm min )
52 ± 2.0
47 ± 1.0
39 ± 1.0
34 ± 0.8
34 ± 0.7
-3 -1
Specific Heat Capacity (MJ m K )
2.39
2.34
2.38
2.31
2.38
Burning Characteristics
Melting and dripping
Melting and dripping
Dripping slowly
Charring
Charring
Oxygen (O )
2
5.1
0.8
0.6
0.9
6.7
Nitrogen (N )
2
5.5
0.2
0.2
6.5
1.2
Carbon dioxide (CO )
2
5.2
4.4
2.2
4.3
29
Air
0.8
0.6
1.9
1.8
2.3
Gas Permeability (in barrer unit)
1
2
3
4
5
crease in aspect ratio of the clay. However, for
higher OC wt%, the WVTR value in-
creased significantly. This is attributed to the ag-
glomeration of the clay and the presence of aluminum
flakes in the polymer matrix. In addition, the abrupt
increase of the WVTR values was associated with the
clay in Batch 4 which may not homogenously mixed
with the polymer matrix as shown in Fig. 3. This result
is associated with the reduction of surface area of OC
when there is an increased organic content of
organobentonite [7]. Figure 3 shows SEM of several
RPA Batches with magnification of 2000x.
-2
The result of the LVTR test of RPA was 0.33 g m
-1
d for 2.36 mm FPALT particle size with 1.0 mm thick.
This gave a perm rating of 0.0018. The data considered
RPA as a leachate vapour barrier material based on
ASTM criteria.
2. Gas Vapour Permeance of GVTR
Results of the GVTR tests presented on Table 1b
show the following:
Batch
4 which has
.
.
.
.
the best performing RPA against O transmission is
2
the batch with 3% OC impregnation. Reduction of
O transmission through RPA with 3% OC impreg-
2
nation was 88%. However, 10% OC impregnation
enhanced O transmission by 32%.
2
the best performing RPA against CO transmission
2
.
390
Senoro et al., Sustain. Environ. Res., 22(6), 387-394 (2012)
Analysis of FTIR data was performed using the Spec-
trum version 5.0.1 software in the infrared spectra of
the material over the wavenumber from 400 to 4000
-1
cm . The FTIR test was carried out in the Physical
Laboratory of Mapua Institute of Technology, Manila,
Philippines. .
RPA Batch No..

The transmission reduction of these gases is attrib-
uted to the morphology of platelet type in clay particles
embedded in a polymer matrix which increases the
diffusion path length by following a 'tortuous path',
leading to the lower permeability [21]. The significant
increases were attributed to the probable uneven dis-
tribution of the clay in the polymer matrix (Fig. 3). A
polymer membrane with a permeability of less than 1
is considered as a moderate barrier. When permea-
bility is < 0.1, the material is considered a good barrier
[22]. The gas permeability values of some batches of
RPA with varying OC ranging from 0.18 to < 1 are
considered as moderate barriers. The data affirm the
study made by Lange and Wyser [23] who found that
the high barrier flexible transparent polymer/clay
nanocomposite packaging films were considered one
of the novel innovations in barrier technologies.
Results of this investigation show that Batch 3 (RPA
with 3% OC impregnation) is the best performing
barrier material among RPAs for O , N , CO . How-
22 2
ever, Batch 2 (RPA impregnated with 1% OC) was the
best performing batch as a barrier material for air. For
GVTR, this was second by the pristine RPA which
may result in a more economical process as it will not
require OC impregnation.
3. Flammability Characteristics of Thermal
Insulation
.
.
Table 2a. ANOVA result on thermal conductivity
Source
Columns
Error
Total
Source
Columns
Error
Total
SS
0.0933
0.0019
0.0952
SS
2870
76
29456
df
4
20
24
df
4
45
49
MS
0.0233
0.0009
-
MS
718
1.7
-
F
247
-
-
F
427
-
-
Prob > F
1.11022E-016
-
-
Prob > F
0
-
-
Table 2b. ANOVA result on rate of burning
Senoro et al., Sustain. Environ. Res., 22(6), 387-394 (2012)
391
the best performing RPAs against N transmission
2
are also the batches with 1 and 3% OC impregna-
tion. Reduction of 97 and 96% was recorded for
RPAs with 1 and 3% OC impregnation, respec-
tively. However, 5% OC impregnation enhanced
N transmission by 18%.
2
the best performing RPAs against air transmission
are pristine RPA with 1% OC impregnation. The
pristine RPA recorded a value of less 1 Barrier
which complies with the ASTM criteria as a mod-
erate gas barrier. Impregnation of 1% OC reduced
the air transmission through RPA by 24%. How-
ever, impregnation of 3 and 5% enhanced air
transmission by 150% and impregnation of 10%
OC enhanced air transmission through RPA by
208%.
is the RPA with 3% OC impregnation. Reduction
of CO transmission through RPA with 3% OC
2
impregnation was 58%. Impregnation of 10%
enhanced the CO transmission to 459%. This
2
means that OC is a catalyst to CO transmission.
2
The physical and chemical processes which in-
fluenced the reduction and enhancement of O and
2
CO transmission in RPA are not sufficiently
2
covered and understood. However, it is associated
with the organic content of OC which affects its
surface area [8] and the intercalation mechanism
[20] that exists between the multilayer plastics,
metalized aluminum, and OC which are factors of
transmission capability of a material. .
.
.
Results of the tests showed that RPA Batch 5, i.
e., with the 10% OC impregnation, has the least
burning rate (Table 1c). RPA Batch 1, with 100%
FPALTs, recorded the highest rate of burning. This
means that Batch 5 is the best thermal insulation
material among the five batches. Hence, the most re-
sistant to fire among the RPA batches. This result is
related to the OC properties making this clay an agent
for fire retardation. Based on the result of statistical
method using ANOVA (Tables 2a and 2b), the impreg-
nation of OC as filler has a significant effect in aiding
the pristine RPA to be a flame retardant material which
is a property necessary for a barrier. Tables 2a and 2b
show an insignificant probability (p)-value which is a
strong indication that addition of OC for each batch is
important as a flame retardant material. The data are
then associated with CO transmission rate test. RPA
2
with 10% OC impregnation enhanced CO transmission
2
and at the same time recorded as the best performing
batch as flame retardant. This phenomenon is similar to
the result of the work of United States Environmental
Protection Agency [24] which considers CO as fire
2
suppressant.
4. Endurance Property with ESCR Capability
Results on FTIR test showed that the RPA speci-
men, even before subjecting to ESCR test, possessed
carbonyl bands, which corresponded the presence of
small degradation. This carbonyl bands are at the
-1
transmittance values ranged from 1725.9-1729.4 cm
as shown in Table 3a and Fig. 4a. The result is ex-
pected as the raw material used (FPALTs) in producing
RPA is an industry waste. Hence probable insignificant
degradation is taking place even before and during the
production of RPA. Result of FTIR on RPA specimen
after ESCR test are shown in Table 3b and Fig. 4b.
The carbonyl groups are illustrated in the infrared
spectra in terms of carbonyl stretching which is usually
the strongest IR signal where the C=O bond of simple
ketones, aldehydes, and carboxylic acids absorb
-1
around 1710 cm . The decrease in intensity of trans-
-1
mission bands at around 1700 cm was associated with
the carbonyl groups which is a manifestation of minute
degradation. Shugar and Ballinger [25] described the
.
.

Table 3a. Wavenumbers of C=O stretching peaks with transmittance values, before ESCR
Table 3b. Wavenumbers of C=O stretching peaks with transmittance values, after the ESCR
Batch
1
2
3
4
5
6
Thickness (mm)
3.00
3.00
3.00
1.84
1.84
1.84
Particle Size (mm)
2.36
1.70
1.00
2.36
1.70
1.00
Area (%T)
24.4
25.3
19.3
16.4
27.9
18.8
Peak Height (%T)
0.66
0.72
0.60
0.51
0.81
0.58
-1
X (cm )
1725.9
1728.4
1728.7
1729.1
1727.6
1729.4
Y (%T)
99.7
99.0
98.7
99.5
98.6
98.8
-1
Legend: %T = percent transmittance; cm = wavenumber unit
Batch
1
2
3
4
5
6
Area (%T)
25.59
19.10
23.80
12.30
24.10
11.20
Peak Height (%T)
0.77
0.59
0.65
0.34
0.69
0.32
-1
X (cm )
1728.8
1729.2
1726.3
1726.8
1726.4
1727.3
Y (%T)
98.8
98.6
98.5
99.2
98.6
99.2
-1
Legend: %T = percent transmittance; cm = wavenumber unit
392
Senoro et al., Sustain. Environ. Res., 22(6), 387-394 (2012)
C=O group of an amide absorbed at an even lower
-1
frequency at 1640-1680 cm . The C=O of an ester
absorbed at a higher frequency range between 1730 to
-1
1740 cm . The peak of RPAs is at around 1725 to 1730
-1
cm in which the bands that correspond to the ester
-1
group are C=O ester (1728 cm ) [26,27] as illustrated
in Figs. 5a and 5b. This associated with the degrada-
tion of PE [28] and PET [29]. However, based on this
result, there is no significant change in the peaks of
carbonyl bands before and after the RPA subject to
ESCR test. This means that the recycling process used
to produce RPAs does not manifest any significant
degradation.
The 1.84 mm thick RPA shows a decreasing per-
centage of transmittance difference which indicates
that there is a resistance to stress cracking as the FPAL
particle decreases. The 2.36 mm FPAL particle size
shows reduction in transmittance while the 1 mm
FPAL particle size has the minimum intensity differ-
ence with the 1.84 mm thick RPA. Therefore, trans-
mittance attenuation divulges when the particle size
becomes smaller with decreasing RPA thickness.
Among the RPA batches tested, Batch 1 has the most
attenuated transmittance value indicating the least
ESCR. The most resistive RPA batch is Batch 6 (1.84
mm thick with 1.0 mm FPAL particle size). This
shows that RPAs having small FPAL particle size and
the thinnest is the most resistant to ESC. This affirms
the result of the study of Senoro [3] that RPA with
100% FPALT has a homogeneous surface morphology.
Tables 3a, 3b and Fig. 4 illustrate the ESCR test result
of the RPA laminates samples which pass the 2000 h
criteria in the ESCR test apparatus without evidence
of cracking. Results of the permeance tests support the
test result of ESCR and FTIR on the capability of
.
Fig. 5. Transmission spectra of Batch 6 by FTIR: (a)
before ESCR test; (b) after ESCR test.
101
100
99
98
97
96
95
94
93
92
3000 2500 2000 1500 1000 574
100
98
96
94
92
90
88
86
84
82
80
78
101
4000 3500 3000 2500 2000 1500 1000 450
Transmission (%T)Transmission (%T)
-1
Wavelength before (cm )
(a)
(b)

RPAs Batch 1-3 to resist against ESC cracking. The
water vapour permeance range of RPAs (pristine and
with OC impregnation) was 0.036 to 0.15 perms. The
-2 -1
LVTR of pristine RPA is 0.33 g m d for 2.36 mm
FPAL particle size 1.0 mm thick which gives a perm
rating of 0.0018. The data thus consider RPA as a
water and leachate vapour barrier material. The GTR
test results further consider RPA as gas vapour retarder
due to GVTR data range from 0.18 to 29 Barrer. .
CONCLUSIONS
Based on the investigation carried out, the results
show that RPA is considered as water vapour barrier
material as it yields a permeance range of 0.036 to 0.15
perms. The best performing batch relative to WVT is
the RPA with 3% OC impregnation. On the other hand,
the GVTR test on O , N , CO and air results in values
22 2
ranging from 0.18 to 29 Barrer which makes RPA as
gas retarder material. Investigation shows that RPA
with 3% OC impregnation is the best performing
barrier material for O , N , CO . However, Batch 2
22 2
(RPA with 1% OC impregnation) is the best per-
forming barrier material for air and second by pristine
RPA. It is further concluded that impregnation of 10%
OC not only enhances the CO transmission into 459%
2
but becomes the best performing RPA material as fire
retardant. The average of the RPA material ranged
-1 -1
from 0.21 to 0.37 W m K which is 2- to 3-fold higher
than the common insulating materials. The impregna-
tion of OC into the RPA improves the resistance of
pristine RPA to fire and acts as an agent to make the
RPA a flame retardant material such as RPA Batch 5.
This is a property necessary for public dwelling use.
Hence, it can be concluded that RPAs impregnated
with OC are materials that perform as fire retardant, as
barrier, and moderate insulator materials. However, the
physical and chemical processes affecting RPAs' capa-
bility as barrier material, when impregnated with OC,
against air, O , CO , water, and leachate are not suffi-
22
ciently understood. Hence, it is required to conduct
further study focusing on the influenced of OC con-
centration in the processes that affect the transport
mechanism in RPA.
The test results of ESCR and FTIR conducted on
six batches of pristine RPAs show that all batches are
resistant to ESC with Batch 6, the least particle FPAL
size and thickness and the most resistant to ESC. This
study further concludes that FTIR approach in investi-
gating the ESCR capability of a material could provide
sufficient evidence of the presence or absence of de-
gradation in the material. Hence, the general con-
clusive statement is that RPAs are water and leachate
vapour barrier, gas vapour retarder, moderate and
thermal insulator. RPAs, regardless of thickness and
FPALT particle sizes, have significant stress cracking
resistivity.
.
.
ACKNOWLEDGEMENTS
It is to acknowledge the financial support from the
Funds for Engineering Development and Institutional
Linkages awarded to Dr. Delia B. Senoro by Mapua
Institute of Technology, and Department of Science
and Technology through the Engineering Research and
Development for Technology Consortium. And Philip-
pine Council for Industry, Energy and Emerging Tech-
nology Research and Development awarded to Albert
Grino and Donamel Saiyari. .
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sion section of a future issue. All discussions should
be submitted to the Editor-in-Chief within six months
of publication. .
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