inlay:
q .
x2.“ 52.3.1.1
:1! 31...: ,

in

”wt;
k 3w”.

«3 ..
e 4.3:.
L: I... ’

«.4
:1
J .zuu
.. .
Shaw:

1..

€43.

 

4.4.125?

 

"um-:mwmram. HA WWW” “a? . , .. . f .5 « .fid 3W9? .9.
. ., .. . ‘, mt? V» v.4”..h. . . . V ,
La , . . ,. ‘ . §.J..2 1,Y\u.‘.

LIBRARY
Michigan State
University

This is to certify that the
thesis entitled

An Analysis of Automobile Pinstriping

presented by

Suzanne Marie Rojas

has been accepted towards fulfillment
of the requirements for the

MS. degree in Forensic Science

 

 

Waiiifif‘i '55“

v 1
Date

MSU is an Affinnative Action/Equal Opportunity Institution

 

PLACE IN RETURN BOX to remove this checkout from your record.
To AVOID FINES return on or before date due.
MAY BE RECALLED with earlier due date if requested.

 

DATE DUE DATE DUE DATE DUE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

6/01 c:/CIRC/DateDue.p65-p.15

 

AN ANALYSIS OF AUTOMOBILE PINSTRIPING
By

Suzanne Marie Rojas

A THESIS

Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of

MASTER OF SCIENCE
Department of Criminal Justice

2005

ABSTRACT
AN ANALYSIS OF AUTOMOBILE PINSTRIPING
By

Suzanne Marie Rojas

Automobile pinstriping can be transferred in automobile collisions Similar to the
transfer of paint. No work has been done to determine the usefulness of analyzing this
evidence to aid in making an association between the source of the pinstripe and the
object it has been transferred to.

The objective of this study was to determine if there were variations present in
pinstriping that could be detected using analytical instruments. A Perkin-Elmer FTIR
spectrophotometer, a Shimadzu pyrolysis gas chromatograph mass spectrometer, and a
SEE microspectrophotometer were used to analyze the decals.

The results are significant because they provide a useful analysis scheme that will
allow the examiner to differentiate between some automobile decals. This study Should

also be used as a starting point for future work in this area.

ACKNOWLEDGMENTS

I would like to thank Dr. Jay Siege] for your continuous support and generosity
through the years. Your dedication to your students and the forensic science field is
amazing! Without your encouragement I would not have finished the program. Thank
you for everything. Thank you to Chris Bommarito for contributing the idea for this
project. I have learned a lot from you and I appreciate you pushing me to work hard.

I would also like to thank my husband, Humberto. Your willingness to sacrifice
while I finished my Masters Degree did not go unnoticed. Thank you for helping me to

do this.

iii

TABLE OF CONTENTS

LIST OF TABLES ........................................................................... v
LIST OF FIGURES .......................................................................... vi
INTRODUCTION ........................................................................... 1
Purpose of this Research ........................................................... 1
Review of the Literature ........................................................... 2
Introduction to the Techniques .................................................... 2
MATERIALS AND METHODS .......................................................... 6
Sample Preparation ................................................................. 6
Fourier Transform Infrared Spectrophotometry ................................. 7
Pyrolysis Gas Chromatography Mass Spectrometry ........................... 8
Visible Microspectrophotometry ................................................. 8
RESULTS
Visual Color Analysis ............................................................. 10
Fourier Transform Infi'ared Spectrophotometry ............................... 10
Plastic Decal Analysis ................................................... 10
Adhesive Analysis ....................................................... 10
Pyrolysis Gas Chromatography/Mass Spectrometry .......................... 11
Plastic Decal and Adhesive Analysis ................................. 11
Visible Microspectrophotometry ................................................ 12
Plastic Decal Analysis ................................................... 12
Damaged vs. Undamaged ......................................................... 12
DISCUSSION ............................................................................... 13
CONCLUSIONS AND FUTURE RESEARCH ....................................... l6
SUGGESTED PROTOCOL .............................................................. 18
APPENDICES .............................................................................. 19
APPENDIX A: Fourier Transform Infrared Spectra ......................... 20
APPENDIX B: Visible Microspectrophotometry Spectra ................... 46
APPENDIX C: Pyrolysis Gas Chromatograms ............................... 71
REFERENCES ............................................................................. 94

iv

LIST OF TABLES

Table 1: List of Pinstripe Samples Used for the Analysis ............................. 6
Table 2: Sample Groups Based on IR Analysis ......................................... 11
Table 3: Sample Groups Based on PGC/MS Analysis ............................... 11
Table 4: Sample Groups Based Visible Microspectrophotometry .................. 12

Figure 1:
Figure 2:
Figure 3:
Figure 4:
Figure 5:
Figure 6:
Figure 7:
Figure 8:
Figure 9:
Figure 10:
Figure 11:
Figure 12:
Figure 13:
Figure 14:
Figure 15:
Figure 16:
Figure 17:
Figure 18:
Figure 19:
Figure 20:
Figure 21:

Figure 22:

LIST OF FIGURES

FTIR Spectrum of Black Pinstripe 1 ........................................ 21
FTIR Spectrum of Black Pinstripe 2 ......................................... 22
FTIR Spectrum of Black Pinstripe 3 ........................................ 23
FT IR Spectrum of Black Pinstripe 4 ......................................... 24
FTIR Spectrum of Black Pinstripe 5 ........................................ 25
FTIR Spectrum of Black Pinstripe 6 ......................................... 26
FTIR Spectrum of Black Pinstripe 7 ........................................ 27
FTIR Spectrum of Black Pinstripe 8 ......................................... 28
FT IR Spectrum of Black Pinstripe 9 ......................................... 29
FTIR Spectrum of Blue Pinstripe l ........................................ 3O
FTIR Spectrum of Blue Pinstripe 2 ......................................... 31
FTIR Spectrum of Blue Pinstripe 3 ........................................ 32
FTIR Spectrum of Silver Pinstripe 1 ....................................... 33
FTIR Spectrum of Silver Pinstripe 2 ....................... . ................ 34
FTIR Spectrum of Silver Pinstripe 3 ....................................... 35
FT IR Spectrum of Silver Pinstripe 4 ....................................... 36
FTIR Spectrum of Red Pinstripe 1 ......................................... 37
FTIR Spectrum of Red Pinstripe 2 ......................................... 38
FTIR Spectrum of Red Pinstripe 3 ......................................... 39
FTIR Spectrum of Red Pinstripe 4 ......................................... 40
FTIR Spectrum of Red Pinstripe 5 ......................................... 41
FT IR Spectrum of Red Pinstripe 6 ......................................... 42

vi

Figure 23:
Figure 24:
Figure 25:
Figure 26:
Figure 27:
Figure 28:
Figure 29:
Figure 30:
Figure 31:
Figure 32:
Figure 33:
Figure 34:
Figure 35:
Figure 36:
Figure 37:
Figure 38:
Figure 39:
Figure 40:
Figure 41:
Figure 42:
Figure 43:
Figure 44:

Figure 45:

FTIR Representative Spectra of Damaged vs Undamaged ............. 43
FTIR Representative Spectrum of Group 1 Adhesive ................... 44
FTIR Representative Spectrum of Group 2 Adhesive ................... 45
Visible MSP Spectrum of Black Pinstripe 1 .............................. 47
Visible MSP Spectnun of Black Pinstripe 2 .............................. 48
Visible MSP Spectrum of Black Pinstripe 3 .............................. 49
Visible MSP Spectrum of Black Pinstripe 4 .............................. 50
Visible MSP Spectrum of Black Pinstripe 5 .............................. 51

Visible MSP Spectrum of Black Pinstripe 6 .............................. 52
Visible MSP Spectrum of Black Pinstripe 7 .............................. 53

Visible MSP Spectrum of Black Pinstripe 8 .............................. 54
Visible MSP Spectrum of Black Pinstripe 9 .............................. 55

Visible MSP Spectrum of Blue Pinstripe 1 ............................... 56
Visible MSP Spectrum of Blue Pinstripe 2 ................................ 5 7
Visible MSP Spectrum of Blue Pinstripe 3 ................................ 58
Visible MSP Spectrum of Silver Pinstripe 1 ........................... g. ..59
Visible MSP Spectrum of Silver Pinstripe 2 .............................. 6O
Visible MSP Spectrum of Silver Pinstripe 3 .............................. 61

Visible MSP Spectrum of Silver Pinstripe 4 .............................. 62
Visible MSP Spectrum of Red Pinstripe 1 ................................ 63

Visible MSP Spectrum of Red Pinstripe 2 ................................ 64
Visible MSP Spectrum of Red Pinstripe 3 ................................ 65

Visible MSP Spectrum of Red Pinstripe 4 ................................ 66

vii

Figure 46:
Figure 47:
Figure 48:
Figure 49:
Figure 50:
Figure 51:
Figure 52:
Figure 53:
Figure 54:
Figure 55:
Figure 56:
Figure 57:
Figure 58:
Figure 59:
Figure 60:
Figure 61:
Figure 62:
Figure 63:
Figure 64:
Figure 65:
Figure 66:
Figure 67:

Figure 68:

Visible MSP Spectrum of Red Pinstripe 5 ................................ 67
Visible MSP Spectrum of Red Pinstripe 6 ................................ 68
Visible MSP Representative Spectrum of Damaged Red Stripe 2. . ...69

Visible MSP Representative Spectrum of Undamaged Red Stripe. . ..70

PGC Chromatogram of Black Pinstripe 1 ................................. 72
PGC Chromatogram of Black Pinstripe 2 ................................. 73
PGC Chromatogram of Black Pinstripe 3 ................................. 74
PGC Chromatogram of Black Pinstripe 4 ................................. 75
PGC Chromatogram of Black Pinstripe 5 ................................. 76
PGC Chromatogram of Black Pinstripe 6 ................................. 77
PGC Chromatogram of Black Pinstripe 7 ................................. 78
PGC Chromatogram of Black Pinstripe 8 ................................. 79
PGC Chromatogram of Black Pinstripe 9 ................................. 80
PGC Chromatogram of Blue Pinstripe 1 .................................. 81
PGC Chromatogram of Blue Pinstripe 2 .................................. 82
PGC Chromatogram of Blue Pinstripe 3 .................................. 83
PGC Chromatogram of Silver Pinstripe 1 ................................. 84
PGC Chromatogram of Silver Pinstripe 2 ................................. 85
PGC Chromatogram of Silver Pinstripe 3 ................................. 86
PGC Chromatogram of Silver Pinstripe 4 ................................. 87
PGC Chromatogram of Red Pinstripe 1 ................................... 88
PGC Chromatogram of Red Pinstripe 2 ................................... 89
PGC Chromatogram of Red Pinstripe 3 ................................... 90

viii

Figure 69: PGC Chromatogram of Red Pinstripe 4 ................................... 91
Figure 70: PGC Chromatogram of Red Pinstripe 5 ................................... 92

Figure 71: PGC Chromatogram of Red Pinstripe 6 ................................... 93

ix

INTRODUCTION
Purpose of this Research

The purpose of this project is to propose a scheme of analysis for automobile
pinstripes. The goal of the scheme is to use a variety of analytical methods to
differentiate one pinstripe from another. Though the decals are class evidence and will
not be able to be individualized, the goal is to put the decals into the smallest group
possible using the analysis scheme. It is also important to consider the time and cost of
the methods that would be involved in the scheme of analysis. Since there have been no
known studies done involving automobile decals, this is an exploratory study which is
designed to investigate the feasibility of using four different methods; visible microscopy,
visible microspectrophotometry, infrared spectrophotometry, and pyrolysis gas
chromatography mass spectrometry, to determine their ability to differentiate pinstripes.

One of the basic principles of forensic evidence centers on the Locard Exchange
Principle. This states in part, “Whenever two objects come into contact there is always a
transfer of material.” Finding evidence from the perpetrator of a crime at the crime scene
places that person there. Likewise, finding evidence from the crime scene on the
perpetrator places the person there as well.

The investigation of a hit and run relies on the transfer of evidence. Trace
evidence is typically transferred. For example, paint or glass from the car may be found
on the victim. Paint or glass from the suspect’s car can then be compared to that removed
from the victim. The transfer could also occur from the victim to the vehicle such as the

deposition of blood from the victim to the car.

Automobiles are sometimes custorrrized with a decal called pinstriping. Like
paint, this can be'subj ect to transfer as well. Two types of pinstripes are available to
consumers. One type of pinstripe is painted on. This can be done at the factory before
the sale of the car or at a body shop after the sale. Pinstripes can also be decals. These
are plastic and have adhesive backs. The decals are mainly composed of polyvinyl
chloride (80-90%). Acrylic adhesive composes about 10-20% of the decal composition.
Trace quantities of organic solvents make up less than 1% of the composition. Again
these can be affixed at the factory, but are more likely to be attached after purchase of the
vehicle, either by a body Shop or the customer.

Automobile decals come in a variety of colors and styles. If transferred during a
collision, this could be very useful evidence. Pinstripes would be considered class
evidence. Because of mass production and the lack of individual characteristics the
source of a pinstripe could be traced back to a group of sources and not one single source.
Though only class evidence, when coupled with paint or glass, the strength of the
association can be quite strong. Also, the pinstripes are not found on all vehicles,
therefore, the mere presence of the pinstripe on the victim and the suspect vehicle could
be significant.

Review of the Literature

An extensive search was done and no literature was found involving automobile

decals or their analysis.
Introduction to the Techniques
Three different instrumental analysis methods were chosen based on schemes that

are used to analyze similar substances, such as adhesive tape and paint. These techniques

are not time consuming and are frequently employed to analyze a variety of substances in
crime laboratories.

Fourier transform infrared spectrophotometry (FTIR) is utilized for the analysis of
substances such as paint, fibers, drugs, and cosmetics. Infi'ared microspectroscopy (IMS)
was Specifically used in this case due to the nature of the small sample size. [MS
combines the use of a microscope with infrared spectrophotometry. This allows for small
areas of a solid sample to be bombarded with infrared radiation. The area of interest in
infrared analysis is from 4000-650 cm". The absorption of infi’ared energy in this region
by the bonds of the substance causes an increase in vibrational energy of the compound.
Because there are numerous vibrational modes, the absorption spectrum, or IR Spectrum,
shows absorbances in specific areas of the spectrum. This is because different bonds
absorb infrared radiation of different wavelengths. The region from 4000-1450 cm'1 can
be used to determine the functional groups of the substance. The region below 1450 cm'1
is considered the fingerprint region. Absorbances in this region are quite complex and
can be used to differentiate dissimilar substances or to confirm that two substances are
similar. IR analysis is typically used for the detection and analysis of organic
components. One of the advantages of this method is the reproducibility of a sample both
on the same instrument as well as among different instruments. In other words, a valid
comparison can be done on two samples that are analyzed on different instruments. The
unique nature of each compound’s spectrum is a major advantage to IR analysis. A
disadvantage to this type of analysis is its sensitivity. Substances that are present in trace

quantities may not be detected.

Pyrolysis gas chromatograph mass spectrometry (PGC-MS) is utilized for the
analysis of substances such as paint, fibers, and accelerants. The sample is introduced
into the pyrolysis unit by placing it in to a small metal cup. The metal cup is dropped
into the pyrolysis chamber. At this point, the sample is heated to high temperatures
ranging from 500-1000°C and travels into the gas chromatograph (GC). In the column of
the GC, the components of the sample are separated based on their attraction to the
column. As the separated components leave the GC, they enter the mass spectrometer
(MS), which functions as the detector. The disadvantage of using PGC-MS is its
difficulty with reproducibility within a sample as well as between instruments. It can be
difficult to make a comparison between two samples run on two different instruments.
PGC—MS is also a destructive test, which is a disadvantage especially with forensic
evidence. PGC-MS is a very sensitive technique, however, and can be very useful in
differentiating substances that vary in their trace components.

Visible microspectrophotometry (MSP) is a nondestructive test that is utilized for
the analysis of substances such as paint, fibers, and cosmetics. It is used to determine the
color of a sample. Although the human eye can ofien easily differentiate between two
samples of different colors, it is more difficult for the eye to discriminate between two
samples of similar color. Color is also subject to an individual’s interpretation. By using
MSP, Similar colors can be compared and differentiated analytically. The sample is
radiated with visible light. The visible range of the electromagnetic spectrum is from 400
to 800 nanometers. When the light that hits the sample has energy that corresponds to an
electronic transition, the energy is absorbed. Electrons absorb this energy, which causes

them to move to a higher energy level. When the electron loses that energy, it may be

detected as visible light. The transitions that correspond to the wavelength of light in the
visible region are recorded by the Spectrophotometer. Both the wavelength where this
occurs and the number of transitions, or magnitude, are shown on the spectrum. This

allows for comparison of spectral characteristics.

MATERIALS AND METHODS

Sample Preparation

Pinstripe samples were collected fi'om 22 different automobiles at a salvage yard.
The samples were chosen mainly based on availability and color. Because the decals are
normally affixed after the sale of the vehicle, the type of car should not have any
correlation with the pinstripe used. However, some pinstripes are put on at the factory,
therefore, the type of pinstripe could correlate to some vehicles. Care was taken to
collect samples from a variety of automobiles. Due to availability constraints, the
pinstripes were collected only from automobiles manufactured from 1985 to 1997. This
could bias the results especially if significant alterations have been made to the decal
composition in the past ten years. Pinstriping from both damaged and undamaged
portions of the automobile were collected from four of the vehicles. A scalpel was used
to remove the samples from the vehicles. 3M brand samples were purchased at the store
in red and black. These two colors were the only solid colors available and corresponded
to the two of the colors removed from the vehicles. The other two colors collected from
the vehicles were silver and blue. Although pinstripes are available in a large variety of
colors, only four colors were utilized in this study. Again, availability constraints were
the reason for the small variety in color sampling.

Table 1: Pinstripe Samples Used for the Analysis

 

 

 

 

 

 

 

 

PINSTRIPE MAKE/MODEL AUTOMOBILE PINSTRIPE
COLOR NUMBER
BLACK 3M SCOTCHCAL NEW 1

BLACK ACURA INTEGRA UNDAMAGED 2

BLACK ACURA INTEGRA DAMAGED 2

BLACK FORD TEMPO 3

BLACK VOLKSWAGON PASSAT 4

BLACK JEEP CHEROKEE 5

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

BLACK FORD SABLE 6
BLACK FORD TAURUS 7
BLACK NISSAN MAXIMA UNDAMAGED 8
BLACK NISSAN MAXIMA DAMAGED 8
BLACK MITSUBISHI MIRAGE 9
BLUE CHRYSLER DYNASTY 1
BLUE TOYOTA TERCEL 2
BLUE CHEVY BERETTA 3
SILVER NISSAN SENTRA 1
SILVER NISSAN PULSAR 2
SILVER OLDSMOBILE ACHIEVA 3
SILVER HONDA CIVIC 4
RED CHRYSLER FIFTH AVENUE 1
RED LINCOLN TOWN CAR 2
UNDAMAGED
RED LINCOLN TOWN CAR DAMAGED 2
RED CHEVY BLAZER UNDAMAGED 3
RED CHEVY BLAZER DAMAGED 3
RED 3M SCOTCHCAL NEW 4
RED JEEP CHEROKEE 5
RED CHRYSLER DYNASTY 6

 

 

 

 

Fourier Transform Infrared Spectrophotometry

The Perkin-Elmer fourier transform infrared spectrophotometer (FTIR) was used
to analyze the pinstripe samples. A small peel of the plastic portion was removed with a
scalpel. The sample was rolled to reduce its thickness. It was then placed on a KBr
pellet. The microscope attachment was used to obtain the transmission spectra of the
samples. The spectra were collected from 4000-650 cm". The spectra were compared to
each other. The spectra from the damaged portion of the cars were also compared with
the undamaged portion of the same car. Selected samples were rerun on subsequent days
to ensure reproducibility. This involved obtaining a new peel from the pinstripe, rolling
it, and obtaining a spectrum.

The adhesive portion of the pinstripes was analyzed in transmission mode using

the FTIR microscope. Due to the thickness of the adhesive, the samples were rerun using

attenuated total reflectance. Using the ATR attachment, the samples are brought into
contact with the crystal. This is achieved by applying pressure to the spring-loaded
apparatus that holds the crystal. The IR beam will enter the crystal, be internally
reflected, and then enter the surface of the sample where the energy will cause an
increase in the vibrational energy of the substance. The Spectra produced were compared
to each other by examining the transmission peaks.
Pmlysis Gas ChromatogIaphy/Mass Spectromet_ry

The Shimadzu pyrolysis gas chromatograph/mass spectrometer (PGC-MS) was
used to analyze the samples. A small portion of the sample was removed using a scalpel.
The sample was placed in the pyrolysis unit. The sample was pyrolyzed at 600°C. A GC
method was created similar to that used for paint samples. The temperature was ramped
from 60°C to 285°C over a 15 minute period with a final hold of 10 minutes. The MS
functioned as the detector. Replicate analysis was done for each sample to test for
reproducibility. The Chromatograms were compared to each other. Samples from
undamaged portions of the vehicles were compared to samples from the damaged
portions to determine if the data would differ depending on the area that the pinstripe was
recovered from.
y_i§ible Microspectrophotometry

The samples were prepared by using a scalpel to remove a small portion of
pinstripe. The sample was rolled on a microscope slide to flatten it. Cargille oil with a
refractive index of 1.500 was used to mount the samples and a coverslip was applied.
The samples were run in absorbance mode on a SEE 1100 instrument with a 20x

objective. The instrument was calibrated according to the SEE manual using NIST

traceable standards. Background spectra were obtained by running a dark scan and
reference scan before each sample analysis. This was done in an area that contained the
Slide, coverslip, Cargille oil, but no sample. Samples were scanned in five different
locations. The sample spectra were compared. Samples from undamaged portions of the

vehicles were compared to samples from the damaged portions.

RESULTS

Visual Color Analysis

Visual color analysis allowed for the separation of the samples into four separate
groups: black, red, blue, and silver. Due to the Size of the samples and their similarity in
color within a color group, it was not possible to visually distinguish between the samples
within a particular color group. If the color of the questioned and known samples is
visibly different, a quick exclusion can be made between them.
Fourier Trflsform Infrared Spectrophotometry
Plastic Decal Analysis

The IR analysis resulted in the formation of twelve groups based on consistent IR
spectra. Each of the 22 spectra contained all of the peaks that are associated with
polyvinyl chloride. All of the spectra also contained a peak at 1730 cm". Differences in
the Spectra occurred mainly in the fingerprint region. The red pinstripe samples also had
additional peaks present from 3300-3000 cm”1 that were not present in the other sample
colors.
Adhesive Analysis

The IR adhesive analysis resulted in the formation of 2 groups based on consistent
IR spectra. Of the 22 samples, 20 Spectra were consistent with each other and the other 2
spectra were consistent with each other. The smaller group, Group 2 adhesive samples,
consisted of the adhesive from the Nissan Sentra and from the Ford Taurus. All other
adhesive samples were categorized into one large group, Group 1. Differences between

the two groups were slight and occurred in the fingerprint region.

10

Table 2: Sample Groups Based on IR Analysis

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

GROUP 1 GROUP 2 GROUP 3 GROUP 4 GROUP 5 GROUP 6
BLACK 1 BLACK 3 BLACK 6 BLACK 7 BLUE 1 BLUE 2
BLACK 2 BLACK 4 BLACK 8 BLUE 3
BLACK 5 BLACK 9
GROUP 7 GROUP 8 GROUP 9 GROUP 10 GROUP 11 GROUP 12
SILVER 1 SILVER 2 SILVER 3 RED 1 RED 5 RED 6
SILVER 4 RED 2
RED 3
RED 4

 

 

 

 

 

 

Pnolysis Gas Chromatography/Mass Spectrometry

Plastic Decal and Adhesive Analysis

The PGC/MS analysis of the samples resulted in 16 groups that represented

consistent spectra. Samples were run in duplicate to check for reproducibility within a

sample. Variability within a sample was considered when examining data for variability

between samples.

Table 3: Sample Groups Based on PGC/MS Analysis

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

GROUP 1 GROUP 2 GROUP 3 GROUP 4 GROUP 5 GROUP 6
BLACK 1 BLACK 3 BLACK 4 BLACK 6 BLACK 7 BLACK 8
BLACK 2 BLACK 5
GROUP 7 GROUP 8 GROUP 9 GROUP 10 GROUP 11
BLACK 9 BLUE 1 BLUE 2 BLUE 3 SILVER 1
GROUP 12 GROUP 13 GROUP 14 GROUP 15 GROUP 16
SILVER 2 SILVER 3 RED 1 RED 5 RED 6
SILVER 4 RED 2
RED 3
RED 4

 

 

 

 

 

 

 

 

ll

 

 

Visible Microspectrophotometry
Plastic Decal Analysis

Using visible microspectrophotometry alone, the 22 samples could be grouped
into 8 groups. The 9 black samples were categorized into 3 groups with consistent
Spectra within each of the 3 groups. One of the groups, which contained 6 of the
samples, showed no significant absorbances and, therefore, were grouped into one group.
Because of their achromatic nature, it is not surprising that these samples did not absorb
in the visible region. The other 2 groups did Show absorbances. The samples, though
black in appearance, could have had colored pigments added to them. It is possible that
the samples were a dark blue or purple instead of the black that they appeared to be.

Table 4: Sample Groups Based on Visible Microspectrophotometry

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

GROUP 1 GROUP 2 GROUP 3 GROUP 4 GROUP 5 GROUP 6
BLACK 1 BLACK 5 BLACK 6 BLUE 1 SILVER 1 RED 1
BLACK 2 BLACK 9 BLUE 2 SILVER 2 RED 2
BLACK 3 BLUE 3 SILVER 3 RED 3
BLACK 4 SILVER 4 RED 4
BLACK 7

BLACK 8

GROUP 7 GROUP 8

RED 5 RED 6

 

 

 

Damaged vs. Undamaged

Four pinstripe samples had a sample that was removed from an undamaged
portion of the vehicle as well as a sample from the damaged portion. Visual color
analysis, infrared microspectroscopy, pyrolysis gas chromatography/mass spectrometry,
and visible microspectrophotometry were done on both the damaged and undamaged
portions in each of these four samples. In each of these types of analysis, the data was

consistent between the damaged and undamaged analysis.

12

DISCUSSION

The purpose of this research was to determine if four different analysis methods
could be used to differentiate pinstripe samples. The conclusion can be made that there
are detectable differences in some of the samples, which will allow for differentiation in
some cases.

The easiest technique to differentiate the decals is visual color analysis. This
allows for a quick inclusion or exclusion. If samples appear to be similar in color or if
one cannot tell due to the small sample Size, then the unknown would be included and
further testing would be done. However, if the colors are easily differentiable with the
human eye, there is no reason to continue testing and an exclusion can be made.

IR analysis is useful in detecting mainly the organic components of the samples.
Although IR is an extremely useful technique, it is not as sensitive as other techniques;
therefore, trace components may not be detectable using IR analysis. The composition of
the decals is 80-90% polyvinyl chloride and 10-20% acrylic; therefore, the majority of
the differences that are being detected using IR are due to the organic components.
However, it is possible that the inorganic components, i.e. the dyes, are present in large
enough quantities to be detected in the infrared spectrum. This is thought to be the case
because none of decals that were different in color had IR spectra that were consistent.

The IR analysis of the adhesive showed that the adhesive used for most of the
pinstripes was the same. In that case, it would not be a useful technique to do for
differentiating between samples. However, if the adhesive used were unusual, it would

allow for a stronger association. It is suggested that the IR analysis on the adhesive

13

should be done due to the ease of analysis and the possibility of being able to make an
exclusion.

Due to the variability within a sample and the number of pyrolysis components,
PGC/MS can be a difficult tool to use for the differentiation of pinstripes. The technique
is very sensitive though, and can detect trace components of the decals. For this reason,
it can be a more discriminating technique than IR which more useful when comparing the
major components of the pinstripes. Because PGC/MS can have problems with
reproducibility, care must be taken to avoid making exclusions that fall into the
variability allowed within a sample. Samples should be run in duplicate to check for
reproducibility and to assess the variability within the sample.

Visible microspectrophotometry did show differences between samples. The
differences in the spectra were primarily consistent with the four main color groups. If i
the colors are visually different, such as red versus black, there would be no reason to do
visible microspectrophotometry because the eye can visually distinguish between the two
colors. Although visible MSP was able to differentiate between two samples of the same
basic color in some cases, it was not able to further differentiate any of the samples. In
other words, IR or PGC/MS was able to differentiate the samples; therefore, MSP would
not need to be done. Visible MSP would only be useful if visual color analysis, IR, and
PGC/MS were not able to differentiate the samples. At that point, MSP could be done to
ensure that the colors were consistent.

Because the manufacturer of the pinstripes is not known, it is possible that the

samples that could not be differentiated were manufactured at the same company.

14

Further studies would need to be done to determine if pinstripes from the same company
are not differentiable and those from different companies are differentiable.

When examining the data for the pinstripes taken from damaged versus
undamaged areas of the automobiles, it can be concluded that it will not change the data
obtained. In each type of analysis, visual color analysis, IR, PGC/MS, and visible MSP,
the data was consistent between the decal removed from the damaged and the undamaged
portions of the car. This is useful information because the sample removed from the
known car would not have to be removed fi'om a Specific area of the car to have an
accurate analysis. However, in each of the samples analyzed, the plastic portion could be
separated from the adhesive portion. Consideration must be given to Situations where the
heat of the collision causes the plastic portion to melt and fuse to the adhesive portion.
The heat of the collision, as well as the fusing of the plastic and the adhesive, could cause
changes in the composition of the decal, which would result in changes to the data during

analysis. The samples in this study did not fit this circumstance.

15

CONCLUSIONS AND SUGGESTIONS FOR FURTHER RESEARCH

The analysis scheme created for differentiating automobile decals is quick and
easy. It allows for differentiation of some samples and at the very least allows for
smaller subsets of the sample groups.

This study was by no means a comprehensive study of all of the types of
automobile decals in use. A more exhaustive study should be done with comparisons
made between manufacturers to determine if manufacturers could be identified from the
analytical scheme. Conclusions must be made with caution though, as some companies
buy their product from another company and attach their name and label to it.

The methods used in this study primarily analyzed the organic components of the
decals. Inorganic analysis, such as Scanning Electron MicroScopy - Energy Dispersive
Spectroscopy (SEM-EDS) could be done to examine the decal for inorganic components.
If present, the inorganic components could be analyzed for variability and used to further
differentiate the decals. Inorganic components would most likely be present in the dyes,
therefore, it is expected that differences would be detected due to the variety of dyes that
are used.

Because this area has not been previously researched, many other studies could be
done. Just as paint has ultraviolet (UV) absorbers, it is possible that the pinstripes do as
well. Aging studies could be done to determine if the decal changes with age and
exposure to UV radiation. Another study could focus on the statistics of the presence of a
decal on an automobile. This in itself could provide valuable information. Because not
all automobiles have pinstripes, the mere presence of the decal itself provides an

association. It would also be interesting to determine the likelihood that a transfer of the

16

decal would take place in the event of a collision. Blind studies should also be done to

ensure that appropriate exclusions and inclusions are being made.

17

SUGGESTED PROTOCOL

Before attempting an analysis, one should decide which analysis methods allow
for the most discrimination. Time of analysis and cost of the method should also be
considered. Another important consideration with forensic evidence is the destructive
nature of the technique. Taking into account all of the above mentioned, the following
scheme of analysis is proposed.

A visual color examination of the pinstripe should be done first. This can allow
for a simple way to classify the sample. Due to the Size of the sample, however, the color
of the decal may not be readily identifiable. Infrared microspectroscopy (IMS) should be
done next. This will allow for comparison of mainly the organic components of the
pinstripes. Pyrolysis gas chromatography mass spectrometry is a very sensitive
technique. However, PGC-MS is a destructive test and can be difficult to interpret. For
these reasons, the test should be performed after IMS if IMS was not able to differentiate
the samples. Microspectrophotometry is useful for differentiating similar colors. If all
other data indicates that the samples are consistent, MSP can be done to examine the
absorbance in the visible region. However, if previous tests have shown that the samples

are not consistent, MSP would not be done.

18

APPENDICES

l9

APPENDIX A

Fourier Transform Infrared Spectra from Sample Analysis

20

 

 

 

 

32.92.8378

ngfismteafifimfim a 8:8.

 

21

 

 

 

 

 

 

 

 

IL

1335 Lasseac .
«ggzsafiaméu seam

 

 

22

iP

 

 

 

 

 

 

 

 

 

352.29..
magefizsaflamgu seam.

 

23

 

 

 

 

 

' D ill

«gadgets-2,.
wgmnfisegg 3.23m.

 

 

 

24

 

 

 

 

 

 

 

09.80531...
mongfisutEafioamE ”m 23m.

25

 

 

 

v
v

v

1

. v

t

 

b 1’ > h P hi LI

 

 

rRlL.

Baum Bo... .
m asses 6.95 B aim «E 6 95mm

 

26

 

 

 

 

 

 

 

reaches?
Aggtefimacu K 83m.

 

 

 

27

’ll b b I llr ’ ' .F F D F F D I D I K

Someone: 2?: can: .
wigsefimanu 62:3

 

 

 

 

 

 

 

 

a («C

 

 

 

 

 

 

 

 

8:: fag:

mflgxgtsifit 695nm.

 

 

< ,

 

29

 

 

 

 

 

 

EEBSO.
Hgogtegyfiu “3 8:3.

 

3O

 

 

 

 

 

 

.88» .85. _
N 853:: 83 t 5.588 «E a: 2:9".

 

 

 

 

31

 

 

 

 

 

 

 

I

8.9.8905.
«855833238..me "Seam .

 

32

 

 

 

 

 

 

 

 

 

gag: .

Higaeig saga:

3

 

 

 

 

A

 

33

 

 

 

 

 

 

 

 

 

 

Ll

 

 

 

.38 .312.
Nglnsefiufimucu S 2:9".

 

34

 

 

 

i=2 £9820
mgcflmzefimfim ”3 23m.

35

 

P I .P D I P I I F P P P 1P 1. L P I

 

 

 

 

 

 

g

voflfimgfifiig "3“ 8:91..

 

853.5...

 

 

w
v
v
r

 

 

 

 

 

 

 

 

 

 

 

Sgimi6_
"33:33.:ng 523m.

 

 

 

37

 

 

 

 

 

 

 

 

 

consent-5 .30 .53. £85 .

NonesmeoeBEpfioame “a 2.3m

 

 

38

D 1? Dr 1' D F l D D L I 1. D ’ I D h I

 

_ laughing
mggseimfit "a 23m.

 

 

 

 

 

 

5
L is

 

 

 

 

 

 

SEES .
vfigEBEBuamaE “883m

 

 

 

v
1
I
. r
,.

4O

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2

 

 

23032053
nosaéimbefimg an 2:8.

 

41

 

 

 

 

 

 

 

 

 

€58.36

68:35.. Eteiméu fleas:

 

42

 

 

 

 

 

 

«35:3.
Bong-Bassoonsassfiamosgéu um 2.5m

. N film/jar...“

1
L

. ~ I

v

r

 

43

 

 

 

 

 

 

 

 

m Ba
222 a See a 5:803 2:55.23. «E an ear .

 

 

 

 

 

 

 

 

 

 

 

 

 

 

5383.

£32 ~ 326% 5.58m «55:883. fit "a 2:8

 

 

 

45

APPENDIX B

Visible Microspectrophotometry Spectra from Sample Analysis

46

_ 888: 6.85% 838% .52 23> em 2%;

Beams—052

b

com 0mm 2p: own can 09‘

 

 

 

xojm ..(UIOhOOm 2n

 

 

 

Ibo.

two.

IN...

In...

12..

law.

aoueqiosqv

47

9205052

:8
L

can
r

can
_

N 8385 6.85% 888% Am: 2&5 ”R 8:5

com
_

com Gov
h _

 

 

 

DD x050 (twp—.2. (”504‘

_..

l

.2.
IN.
V
m
0
. w
:3 u
3
a
In.
.8.

IV.

 

 

48

2268052

23
_

cow
_

2.:

m Basses 6.8.30 838% Am: 0535 ”mm BEE

coo
_

own owe

 

 

 

x0<4m OQENP 010".

Imo.

TP.

In...

aaueqrosqv

 

ImN.

 

49

 

 

EeawEocuz
com
_

2.5

cos
_

4 seems: spam so 888% .52 23> ”am 2:5

com
_

2.5

oov
L

 

 

x050 ...(mwdi ZOO<>>w¥40>

law.

aoueqmsqv

1mm.

 

 

50

 

ewumEOcmz

2.5

2.5

can
_

m 838: case do easam am: 52> Mom 2:5

com
_

com 03.
_ _

 

 

 

 

xojm mwammIO mum...

 

 

In...

anueqrosqv

51

 

 

222552 0 BABE: case co egoam mm: 2£e> Sm Sam;

25 can own 2.5 2.3 Gov

 

xojm m4m<w 010....

 

Imo.

aoueqiosqv

 

 

52

 

 

 

223052 A Bees: case .a 825% am: 2&5 ”mm semi
0mm 2.5 on: 2.5 own 00¢
xojm w3¢3<h 0M0“—

IF.

 

 

Imo.

aoueqiosqv

53

ESOEocaz

w 8885 seem? 8.58% .52 use; ”mm gamma

 

 

 

 

:8 com on» com cam ocv
— P _ _ _ _ .
OD xojm (Sans). Z<mm_z
h.
In.
rm.
IF
l_..w
1&6
In...
Icé

 

 

aoueqiosqv

54

EOaNEOr—wz

cam
_

com
.

o2.
_

a 838: case do seesaw mm: 2£a> em 2&5

com
_

2.9m

 

 

 

xojm m0<¢=z Ema-49:2

84
12.
IN.
V
q
S
m
U
3
ran. a
In.
1...».

 

 

55

 

 

 

gasses: _ 8&5 85 do 58% Am: 23> ”mm 2:5
com com Och can cam GOV
— — _ — _ b 1
MDJQ tw<2>fl ¢m4m>MIU

 

 

lac.

 

 

..ma.

lac.

aoueqiosqv

56

2205052

com
_

o2.
.

N 2:55 SE :6 88.8% mm: 2&5 am 2%:

coo
_

com cow
_ P

 

 

 

man—m ..womm... <._.O>O._.

 

 

IND.

Iva.

loo.

lac.

luv.

Ive.

aauquosqv

57

emamEOe—GZ

2.5

new
_

ooh
_

m Marga 25% 8:58am mm: 23> ”R 2%;

coo
.

2.3

2.:

 

 

mqu (tummm >>mIo

 

 

aoueqmsqv

_ 2:535 525 («o 6.58% mm: 0355 “mm 2%:

 

 

 

2308052
com 8a 2:. com com , 2:~
p . _ L p _
mm>.=m (mhzmw 25.6.2 .6

Two.
13.
:8.
Inc.

Iv.
IN V.

 

 

aaueqaosqv

59

N 3385 525 mo 828% mm: 2%; 5m 2:5

 

 

 

2205052
com can con com com oov
_ _ _ . _ .
mm>£w yawn—Dn— 2<mm_2

lo
INO.
IS.
12..
1°.

 

 

 

IN...

aoueqmsqv

6O

229.552
2.3

can
r

can
b

m ages 52% (8 633% mm: 23> How 2:5

com
_

com 3%
g .

 

 

 

mm>.=m <>m=._o< mimOEmn—n—O

WNo.

Iva.

Imo.

loo.

INF.

 

 

aouemosqv

61

 

 

 

EEmEocaz
v 2:58: 525 Mo 83.8% mm: 0363 H: 05mm
8a com 2K 25 can out
_ p b _ _ _
mm>.=m 0.20 «520...

 

Imo.

aaueqmsqv

Luv.

 

 

62

2305052

com
r

can

con
_

_ 3385 Ba mo :58on mm: m“33> US via

com
_

can one
_ L

 

 

 

Dwm m32m>< Ir...“— mm4m>110

 

 

Inc.

19..

aauemosqv

63

232.5252

com
_

o2.
_

N 358: Ba Mo Essay, mm: 2e; “Q 2:5

com
_

com 8?
_ p

 

 

 

0: 0mm m<0 230... 24002..—

 

 

TNO.

Inc.

Too.

1:.

aauemosqv

64

 

 

 

9.23052 m 2:55 Ba Mo 823% mm: 0355 ”3 2:3
com com DOB 006 com GOV
— — _ P — —
lo
03 0mm mmNSm >>mIU
IF.
.N.

 

 

aouquosqv

65

 

 

#8 8585 8a Mo 888% mm: 8385 ”3 8:5

 

930E232
com cow 2:. can can cov
_ _ P _ P
0mm ._<oxo._.oom in

.8.

:3.

12...

no.

I...
luv.
13..

 

 

aaueqaosqv

66

m 8585 8m 8o 588% mm: 837.3 ”3 8%;

 

 

 

8268052
cam can can com com Dov
P _ - _ _ _
0mm KmmZOE mmxommT—U mum...
Inc.
[F0
[m r.
V
m
0
.~ m
U
0
a
Law.
A.
lmm.

 

 

67

WhfiaOF—OCWZ

coo
.

och
-

o 8385 8m 80 a§8% mm: 8585 é 28a

com com 00¢
- _ _

 

 

 

0mm >._.m<z>o MMJm>mIU

 

 

aoueqmsqv

68

 

 

9.205052

90¢
_

N 3525 BM cums—~80 mo :53on o>uficomoaom mmE 0365 ”M3 onE

can
.

2:.
L

060
_

com cow
r _

 

0 0mm m<0 Z>>Oh 24002...

Imo.

aoueqmsqv

lmr.

lmu.

 

 

69

229-552

cam
.

N 2.535 to”. vuwmfimucD ..o 836on 03558.32 mmS. 037.5 Nov oSmE
own oov

ecu
_

och
_

com
_

 

 

 

0... 0mm m<0 2.50... 24002...

 

 

Inc.

lvo.

Imo.

Inc.

In...

aouquosqv

70

APPENDIX C

Pyrolysis Gas Chromatograms from Sample Analysis

71

. 8.585 8.85 .0 $8085.50 69. ”on 88E

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

. . a. _ . .s. .r a.

.. f

i . m
.6 ‘6 .

,

_ m

.

.

 

 

 

 

 

 

 

 

72

. —.-_—.. -..“-——_-_.. . ——. ._..——..... —- —.v..—-__ .__--

ill/37?.

 

 

N 8585 v.858 $898530 00“. ”.m 85w...

b b h

»

w—._———
‘—

.__ .__

_.

 

 

 

 

 

 

r—“x-‘Am-y
_____.— ...__———.—

 

 

 

 

 

 

Zéggégfija 5...), 33%;...2}. \\;
r, _. _ .. ......\.....\

 

 

 

 

 

 

- ..__. __.._-.__ ...r- ,i_..

73

m 2.585 8.8:. .0 sameneoso 69. ”mm 83mm

 

 

 

.

 

.3: arias}

.

.

 

 

 

 

 

 

 

 

 

 

 

74

 

v 8.85.. U.85 .0 $828536 09. an exam

 

._ a .. 3... is 2,

 

 

 

 

 

 

 

 

 

 

 

 

 

f . ---.._-———-v——
.14.-“—
—_——

.,
-....-._.

 

 

r :13:

a»:

 

_-_....____._-_._.._...-J

 

75

m 2.585 8.85 mo 5588585 02 em 85?.

 

b p p s{ r
, D

 

 

.

.

y
.

fl

.3!

«qj€4§.fl www.mrdl. {..l ..wmmwar‘l . fjflflvéwfiffiuww

.32. ,

a-A:

 

 

 

 

76

 

 

 

 

 

 

o 2.385 8.85 us 888085020 R: ”mm. 8%:

, a}...

L . r . p . b b
. a]...

_ . 4...; ..

 

 

 

 

 

 

 

 

 

 

.-. —.——.- ---— --

 

77

N. 2.533 6.85 .«o ESonEoEU 00m ”cm 05E”.

 

 

 

 

 

 

.4.

 

 

 

 

 

 

—.—_

 

 

 

 

»— ..-._—. .H. ——h

 

-__.__.._._-.., —

~u'——_. -..W.

 

 

78

 

w 8.585,. 8.85 .o $808505 09. gm 2.8:.

 

5T g P r

< .333 A , i _. . _ 3.. $3.. gig/$3
6.
._ ._

.L

\
-—-———«

.
.
M

.

 

 

 

 

. .,._._.... .. _‘._..

 

 

 

 

 

 

 

 

 

 

 

 

 

 

79

 

 

 

 

a 2.585 fig .8 anoaeoao 02 ”mm 2:5

_ i . w .2,
a. :fljgsfij jix
_ .

 

 

 

 

——...—.-———'_.—-

 

 

~—.—.—
...r

M
_ “..—
“w“.

 

 

 

 

 

 

 

 

 

,—_—
‘ .—..-‘ . ..a—‘wr—M

 

 

u_._._- w...

 

80

_ 3535 035 .«o Samoan—050 00m ”mm oSmE

 

 

«333

 

 

 

 

 

 

 

. 2:

 

g

 

EEE EE

9 .

E

...—
—_._.-—-

i

_

-—_-g.-. .' .—

a)?

-
\
L
\

 

 

 

 

 

 

 

81

 

N 3.525 85 Mo Suwoasoao 03 5e 8&5

L _

 

 

 

 

 

 

_

.3»JE§$. . f N
E E i 3%

 

 

 

‘m

 

- man—'3‘. ‘ ‘

 

82

m acid; 85 96 8322030 02 go 2:5

r P LII

 

 

 

 

.44..

E .E. .3; E 4.32—— E. ___ =. .L St
w J;

Jr...

9-..-

.———. .
.—.——_- --
H ‘4

 

.‘1'9.

 

 

 

 

 

 

 

 

 

 

-..a- .m..___.-v .-.. v-----

 

 

 

83

 

_ 2.585 52% mo gaseoau com ”S 2%;

 

 

 

 

 

 

 

 

 

 

 

 

 

E
, M

M

_

 

 

 

 

 

 

 

 

 

 

 

84

N 852:.— sza ‘8 seweaaoau 0cm ”8 95mm

 

 

 

 

 

r b D!

\

 

 

 

 

 

 

 

 

 

 

1:?
bad-L7

 

 

 

 

 

 

. . A”--._ _. _._.._.— ...—.—-1

 

 

85

 

m 2:535 B>=m mo EmeEoEU 00m #6 PSwE

 

 

 

 

 

 

L

P

. _ 35,...1d 3%; *3:

 

 

 

 

 

 

 

E. E,%.Ejjfi._ “j
_ ,._ ,_. g ,5
__ M i;
w j
__ __m
u
E

 

 

86

 

 

v 3523 52% mo Efiwofifiofio DOA ”we uSwE

— h b! L ’ h L-

 

 

 

 

 

 

 

 

 

: _ 3 ..

 

 

 

“fif-

"Ia-

 

 

 

 

 

 

 

 

 

43.5; -

 

87

 

_ 8.525 8m we $838030 02 ”8 2:5

r

 

 

 

 

 

 

 

 

 

 

 

 

__'._“= “-

 

 

 

 

88

 

a 8.58“; Ba mo $835020 02 ”3 2:5

L7 r b bl } — . . l u —

 

 

 

 

1141...? E a E

 

 

 

 

 

 

 

 

 

 

 

 

_ —
._ 15.....— . .—
‘— cu..-“

 

 

 

 

.mw.___._~-fl-,-

89

If"

m 8.58: Ba Mo 8.393020 02 ”we 2:5

p

 

 

 

 

j. e E:
3 ,_

 

 

:

 

 

.3

 

E €32».

_
_

7.

 

d.

_

$374.23.

2.;

L

E..._

,

,

 

 

 

 

b
.‘I I‘ll"—

 

90

P L D h u

v 8:35 Ba .8 £03830 03 am 3&2

L

 

 

 

 

{a c «a. ..:. 1.;1i1 .fljgjq «3. . ._ «SjrgfimJ/fij

 

 

 

3% E

I * — PH_'

 

 

 

lb.

 

‘

 

 

 

91

m 852: Ba .6 $93830 00m ”E 2%;

b! - P,

 

 

 

jg: _ .

 

 

 

 

 

 

 

 

 

 

 

..__-.._._.. . V..J

__.,—_—.._.‘._ -V-~_E-_.—____rr_._.fv-.—_..—._.m--_.—_‘ ..____.____._ ,_ ._._..__...——“ -~._ -- -.

92

 

 

o 83mg Ba 3 88838050 mom E: 2&3

. _ EEE 43E
E E F

 

P

E E E E2, gujaersédwxyg
E E

 

E

 

E

E

L l

 

EEE
E
E

E
E

E

 

 

93

REFERENCES

94

REFERENCES

Saferstein, Richard. Foren_sic Science Handbook, Volume II. Prentice Hall 1988.
Saferstein, Richard. Forensic Science Hgdbook, Volume I. Prentice Hall 2002.

Humecki, Howard. Practical Guide to Infrng Microspectroscopy. Marcel Dekker, Inc.
1995.

95

   

IIIl'IjljfljllflEIjlji111]]le