Papers by M E Hossain, PhD, PE
In this study, sonication dispersion technique was employed to infuse 0.1–0.4 wt.% carbon nanofib... more In this study, sonication dispersion technique was employed to infuse 0.1–0.4 wt.% carbon nanofibers (CNFs) into polyester matrix to enhance thermomechanical properties of resulting nanocomposites. The effect of dispersion conditions has been investigated with regard to the CNF content and the sonication time. X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) micrographs revealed excellent dispersion of
0.2 wt.% CNF infused in polyester, resulting in enhanced mechanical responses. Polyester with 0.2 wt.% CNF samples resulted in 88% and 16% increase in flexural strength and modulus, respectively, over the neat one. Quasi-static compression tests showed similar increasing trend with addition of CNF. Fracture morphology study of tested samples
revealed relatively rougher surface in CNF-loaded polyester compared to the neat due to better interaction between the fiber and the matrix. Dynamic mechanical analysis (DMA)
study exhibited about 35% increase in the storage modulus and about 5 C increase in the glass transition temperature (Tg). A better thermal stability in the CNF-loaded polyester was observed from the thermogravimetric analysis (TGA) studies. Best results were obtained for the 0.2 wt.% CNF loading with 90 mins of sonication and 50% sonication amplitude. It is recommended that this level of sonication facilitates suitable dispersion of the CNF into polyester matrices without destroying the CNF’s structure.
We report the activation field and selective frequency-dependent ferroelectric behavior of BaMn3T... more We report the activation field and selective frequency-dependent ferroelectric behavior of BaMn3Ti4O14.25 (BMT-134) at room temperature. BMT-134, a recently discovered multiferroic complex oxide, exhibits antiferromagnetic and ferroelectric behavior and belongs to the hollandite crystal class. The microstructure can be manipulated through processing conditions to prepare a nanocrystalline textured tablet. We measured polarization-electric field (P-E) hysteresis loops and strain-electric field butterfly loops as a function of frequency in order to investigate the AC dynamics of domain switching and strain behavior. Under an electric field loading condition, a clear hysteresis loop of the electric field-displacement curve is obtained at 50 Hz, indicating that room
temperature ferroelectricity is attainable under the right processing conditions. When the frequency is increased to 500 Hz, the coercive field also increases, until the frequency reaches 5 kHz, at which point the electric field versus electric displacement becomes linear indicating the limit of domain
switching at high frequency.
Springer-Verlag Wien 2014, Jan 18, 2014
In this paper, based on recent research on BaTiO3 (BT) nanoparticles, BT/P(VDF-HFP) nanocomposite... more In this paper, based on recent research on BaTiO3 (BT) nanoparticles, BT/P(VDF-HFP) nanocomposites,
frequency-dependent dielectric properties of such a material system with high energy density have
been investigated as functions of the volume fraction of the nanoparticles at room temperature by several
theoretical models. For single domain and single crystals of BT, a Debye type of dissipation and soft mode
theory have been adopted to obtain a more precise frequency-dependent dielectric spectrum of BT. For nanodielectric
composites, among the others, Wiener Rule, Lichtenecker model, Maxwell–Wagner model, Yamada,
andmodified Kernermodel were applied to evaluate the frequency-dependent dielectric spectrum of nanocomposites.
A simple rule of mixture for the dielectric loss tangent was obtained using Lichtenecker logarithmic
rule. The results from theoretical calculations are compared with the experimental data. For the dielectric
constant, Lichtenecker model, Maxwell–Wagner model, and Yamada model show reasonable agreements with
the experimental data up to 50% volume fraction of the nanoparticles. At the higher volume fraction of the
nanoparticles, the experimental data show a decreasing trend of the dielectric constant of the composites due
to an increase in porosity of the system. In this case, a three-phase model (nanoparticles/pores/matrix) was
developed to predict dielectric properties of the system at higher volume fraction of the nanoparticles (up to
80 %). The results showed reasonable agreements for a wide range of frequency. This theoretical study provides
an essential information on dielectric properties of polymer-based BT nanocomposites with a wide frequency
range instead of the trial-and-error strategy of experiments and can be used for designing high energy density
dielectric materials in the future.
MRS bulletin / Materials Research Society, Jan 2011
ABSTRACT In this study, different dispersion techniques such as sonication at high frequency, mec... more ABSTRACT In this study, different dispersion techniques such as sonication at high frequency, mechanical mixing, and magnetic stirring methods were employed to infuse 0.1 to 0.4 wt.% carbon nanofiber (CNF) into polyester matrix to study the influence of CNF on mechanical and thermal properties of the polyester nanocomposites. Dispersion of CNF studied using scanning electron microscopy (SEM) micrographs revealed excellent dispersion of CNF using sonication when 0.2 wt.% CNF was mixed in polyester resulting in enhanced mechanical response. On the other hand, agglomerations were observed in samples prepared with other mixing methods. Polyester with 0.2 wt.% CNF samples prepared by sonication resulted in 88% and 16% increase in flexural strength and modulus, respectively, over neat samples. Quasi-static compression tests showed similar increasing trend with addition of 0.2 wt.% CNF. Dynamic mechanical analysis (DMA) showed 35% and 5 °C improvement in the storage modulus and glass transition temperature (Tg), respectively, in the 0.2 wt.% loaded samples. Thermal mechanical analysis (TMA) performed on neat and samples with 0.2 wt.% CNF showed lower coefficient of thermal expansion (CTE) in nanophased sample compared to neat. Fracture morphology evaluated using SEM revealed relatively rougher surface in CNF-loaded polyester compared to neat as a result of better interaction between fiber and matrix due to the presence of CNF.
Abstract: A significant improvement in fiber reinforced polymeric composite (FRPC) materials can ... more Abstract: A significant improvement in fiber reinforced polymeric composite (FRPC) materials can be obtained by
incorporating a very small amount of nanofiller in the matrix material. In this work, an ultrasonic liquid
processor was used to infuse carbon nanofiber (CNF) into the polyester matrix which was then mixed
with catalyst using a mechanical agitator. Both conventional and CNF-filled glass-fiber reinforced polyester
composites (GRPC) were fabricated using the vacuum assisted resin transfer molding (VARTM) process.
Excellent dispersion of CNFs into the polyester resin was observed from the scanning electron
microscopy (SEM) micrographs. Flexural and quasi-static tests were performed for investigating the
mechanical responses. Fracture surface was examined using optical microscopy (OM) and SEM. Flexure
tests performed on the conventional GRPC, 0.1–0.4 wt.% CNF-filled GRPC showed up to 49% and 31%
increase in the flexural strength and modulus, respectively, compared to the conventional one with
increasing loading of CNFs up to 0.2 wt.%. Similar trend was seen in quasi-static compression properties.
SEM evaluation revealed relatively less damage in the tested fracture surfaces of the nanophased composites
in terms of matrix failure, fiber breakage, matrix–fiber debonding, and delamination, compared
to the conventional one. This might be the result of better interfacial interaction between matrix and
fibers, due to the presence of CNFs.
ASME2012
ABSTRACT With climbing worldwide oil prices and global warming, energy crisis poses a threat to l... more ABSTRACT With climbing worldwide oil prices and global warming, energy crisis poses a threat to living standards, economy, and even global environment. Nanodielectrics become one of the new materials activated to play a unique role in sustainable and clean energy production, energy transportation, energy storage, and end usage. Based on our recent research on frequency-dependent dielectric properties of BaTiO3 (BT) single domain, BT/parylene nanodielectric composites have been examined in wide-ranging frequency at room temperature by several theoretical models. The projected models combined with Debye type of dissipation and soft mode theory to obtain more precise frequency dependent dielectric spectrum. Among the others, Wiener mixture rule, Lichtnecker model, Rayleigh model, Yamada rule, Maxwell-Wagner model, modified Kerner model were used to find frequency dependent nanocomposites dielectric spectrum. The predicted results are compared with our experimental results and explored the frequency dependent dielectric behavior of nanodielectric composites. The dielectric constant decreases while dielectric loss increases with increasing frequency due to at very high frequency, only electronic polarization can occur. This investigation provides the fundamental knowledge on dielectric properties of nanocomposites with a wide frequency range instead of trial-and-error strategy of experiments for the future development of energy storage devices.
ABSTRACT Nanodielectric materials become one of the key materials to play an important role in su... more ABSTRACT Nanodielectric materials become one of the key materials to play an important role in sustainable and clean energy production, energy transformation, energy storage, and end usage in terms of energy storage capabilities due to the trade-off between dielectric constant, dielectric loss and voltage breakdown. Based on our recent research on BaTiO3 (BT) nanoparticles, BT/Parylene and BT/P(VDF-HFP) nanocomposites, frequency dependent dielectric properties of such material systems with high energy density have been investigated as a function of the volume fraction of nanoparticles at room temperature by several theoretical models. For single domain and single crystals of BT a Debye type of dissipation and soft mode theory has been developed to obtain more precise frequency dependent dielectric spectrum of BT. For nanodielectric composites, among the others, Lichtnecker model, Maxwell-Wagner model, Yamada, and modified Kerner model were adopted to evaluate frequency dependent dielectric spectrum of nanocomposites. A simple rule of mixture for the dielectric loss tangent was obtained using Lichtnecker logarithmic rule. The results from theoretical calculations are compared with the experimental data. For dielectric constant, Lichtnecker model, Maxwell-Wagner model and Yamada model show reasonable agreements with the experimental data up to 50% volume fraction of the nanoparticles. For dielectric loss, the simple rule of mixture gives good predictions for a wide frequency range showed reasonable agreements for a wide range of frequency. This theoretical study provides an essential information on dielectric properties of polymer-based BT nanocomposites with a wide frequency range instead of trial-and-error strategy of experiments and can be used for designing high energy density dielectric materials in the future.
Keywords: Nanodielectrics, Dielectric Properties, BT, Nanocomposites, Frequency-Dependent
Composites Part A-applied Science and Manufacturing, Aug 6, 2011
A significant improvement in fiber reinforced polymeric composite (FRPC) materials can be obtaine... more A significant improvement in fiber reinforced polymeric composite (FRPC) materials can be obtained by incorporating a very small amount of nanofiller in the matrix material. In this work, an ultrasonic liquid processor was used to infuse carbon nanofiber (CNF) into the polyester matrix which was then mixed with catalyst using a mechanical agitator. Both conventional and CNF-filled glass-fiber reinforced polyester composites (GRPC) were fabricated using the vacuum assisted resin transfer molding (VARTM) process. Excellent dispersion of CNFs into the polyester resin was observed from the scanning electron microscopy (SEM) micrographs. Flexural and quasi-static tests were performed for investigating the mechanical responses. Fracture surface was examined using optical microscopy (OM) and SEM. Flexure tests performed on the conventional GRPC, 0.1-0.4 wt.% CNF-filled GRPC showed up to 49% and 31% increase in the flexural strength and modulus, respectively, compared to the conventional one with increasing loading of CNFs up to 0.2 wt.%. Similar trend was seen in quasi-static compression properties. SEM evaluation revealed relatively less damage in the tested fracture surfaces of the nanophased composites in terms of matrix failure, fiber breakage, matrix-fiber debonding, and delamination, compared to the conventional one. This might be the result of better interfacial interaction between matrix and fibers, due to the presence of CNFs.
http://www.sagepublications.com, Mar 25, 2013
Abstract
A significant improvement in fiber-reinforced polymeric composite materials can be obta... more Abstract
A significant improvement in fiber-reinforced polymeric composite materials can be obtained by incorporating a very
small amount of nanofillers in the matrix material. In this study, an ultrasonic liquid processor was used to infuse carbon
nanofibers into the polyester matrix which was then mixed with a catalyst using a mechanical agitator. Both conventional
and carbon nanofibers-filled glass fiber-reinforced polyester composites were fabricated using the vacuum-assisted resin
transfer molding process. Low-velocity impact tests was performed at 10 J, 20 J, and 30 J energy levels on conventional as
well as 0.1–0.3 wt% carbon nanofibers-filled glass fiber-reinforced polyester composites using Dynatup8210. The morphology
of fractured specimens was examined using digital photographs and optical microscopy. There was an increase in
the peak load for the nanophased glass fiber-reinforced polyester composites compared with the conventional one. The
absorbed energy of nanophased glass fiber-reinforced polyester composites was less than that of conventional one at
different energy levels. The extent of damage was more pronounced in the conventional glass fiber-reinforced polyester
composites compared to nanophased ones. Failure mechanisms comprised of indentation, debonding, delamination,
matrix cracking, and fiber fracture. The extent of damage was pronounced in conventional composite compared to
nanophased ones.
Keywords
CNF, fiber-reinforced composites, VARTM, low-velocity impact
International Journal of Quality and Innovation, 2010
Abstract: Service industries have become very competitive and customers are
more concerned about... more Abstract: Service industries have become very competitive and customers are
more concerned about quality today. Customers nowadays are very choosy for
spending money. Quality product or service is their first and foremost
preference. For a service provider, the challenge is to tune up their service with
all desirable qualities so that the customers’ expectations are met. This paper
focuses on the application of quality function deployment on a utility service
company to improve its quality of service through designing the house of
quality matrix. The objective of this work is to provide the case company:
DESCO that distributes and commercialises electrical energy with a
methodology that allows them to identify the focal point of their organisation.
This should also determine on which processes, customer service channels or
other services, they should concentrate in order to satisfy their customer’s
expectations while continuously improving quality.
Keywords: quality function deployment; QFD; utility service; house of
quality; HOQ; voice of customer; VOC.
a b s t r a c t
A high intensity ultrasonic liquid processor was used to infuse 0.1–0.4 wt.% car... more a b s t r a c t
A high intensity ultrasonic liquid processor was used to infuse 0.1–0.4 wt.% carbon nanofibers (CNFs) into
the polyester matrix which was then mixed with a catalyst using a high speed mechanical agitator. Both
conventional and nanophased glass fiber reinforced polyester composites (GRPCs) were fabricated using
the vacuum assisted resin transfer molding (VARTM) process. Scanning electron microscope (SEM)
revealed best dispersion of CNFs in the 0.2 wt.% CNF-loaded resin. Proper resin flow and impregnation
of the glass fibers were also seen in the SEM micrographs. DMA studies exhibited about 49.5% increase
in the storage modulus and about 3 C increase in the glass transition temperature (Tg) due to the incorporation
of CNFs into the GRPC. TMA studies also showed better thermal stability and lower thermal
expansion in the CNF-loaded GRPC. CNF-loaded GRPC showed higher ILSS due to better interfacial
bonding between the fiber and matrix due to the presence of CNFs. Fracture morphology studied by both
optical microscope (OM) and SEM revealed better interfacial bonding in the CNF-loaded GRPC.
Uploads
Papers by M E Hossain, PhD, PE
0.2 wt.% CNF infused in polyester, resulting in enhanced mechanical responses. Polyester with 0.2 wt.% CNF samples resulted in 88% and 16% increase in flexural strength and modulus, respectively, over the neat one. Quasi-static compression tests showed similar increasing trend with addition of CNF. Fracture morphology study of tested samples
revealed relatively rougher surface in CNF-loaded polyester compared to the neat due to better interaction between the fiber and the matrix. Dynamic mechanical analysis (DMA)
study exhibited about 35% increase in the storage modulus and about 5 C increase in the glass transition temperature (Tg). A better thermal stability in the CNF-loaded polyester was observed from the thermogravimetric analysis (TGA) studies. Best results were obtained for the 0.2 wt.% CNF loading with 90 mins of sonication and 50% sonication amplitude. It is recommended that this level of sonication facilitates suitable dispersion of the CNF into polyester matrices without destroying the CNF’s structure.
temperature ferroelectricity is attainable under the right processing conditions. When the frequency is increased to 500 Hz, the coercive field also increases, until the frequency reaches 5 kHz, at which point the electric field versus electric displacement becomes linear indicating the limit of domain
switching at high frequency.
frequency-dependent dielectric properties of such a material system with high energy density have
been investigated as functions of the volume fraction of the nanoparticles at room temperature by several
theoretical models. For single domain and single crystals of BT, a Debye type of dissipation and soft mode
theory have been adopted to obtain a more precise frequency-dependent dielectric spectrum of BT. For nanodielectric
composites, among the others, Wiener Rule, Lichtenecker model, Maxwell–Wagner model, Yamada,
andmodified Kernermodel were applied to evaluate the frequency-dependent dielectric spectrum of nanocomposites.
A simple rule of mixture for the dielectric loss tangent was obtained using Lichtenecker logarithmic
rule. The results from theoretical calculations are compared with the experimental data. For the dielectric
constant, Lichtenecker model, Maxwell–Wagner model, and Yamada model show reasonable agreements with
the experimental data up to 50% volume fraction of the nanoparticles. At the higher volume fraction of the
nanoparticles, the experimental data show a decreasing trend of the dielectric constant of the composites due
to an increase in porosity of the system. In this case, a three-phase model (nanoparticles/pores/matrix) was
developed to predict dielectric properties of the system at higher volume fraction of the nanoparticles (up to
80 %). The results showed reasonable agreements for a wide range of frequency. This theoretical study provides
an essential information on dielectric properties of polymer-based BT nanocomposites with a wide frequency
range instead of the trial-and-error strategy of experiments and can be used for designing high energy density
dielectric materials in the future.
incorporating a very small amount of nanofiller in the matrix material. In this work, an ultrasonic liquid
processor was used to infuse carbon nanofiber (CNF) into the polyester matrix which was then mixed
with catalyst using a mechanical agitator. Both conventional and CNF-filled glass-fiber reinforced polyester
composites (GRPC) were fabricated using the vacuum assisted resin transfer molding (VARTM) process.
Excellent dispersion of CNFs into the polyester resin was observed from the scanning electron
microscopy (SEM) micrographs. Flexural and quasi-static tests were performed for investigating the
mechanical responses. Fracture surface was examined using optical microscopy (OM) and SEM. Flexure
tests performed on the conventional GRPC, 0.1–0.4 wt.% CNF-filled GRPC showed up to 49% and 31%
increase in the flexural strength and modulus, respectively, compared to the conventional one with
increasing loading of CNFs up to 0.2 wt.%. Similar trend was seen in quasi-static compression properties.
SEM evaluation revealed relatively less damage in the tested fracture surfaces of the nanophased composites
in terms of matrix failure, fiber breakage, matrix–fiber debonding, and delamination, compared
to the conventional one. This might be the result of better interfacial interaction between matrix and
fibers, due to the presence of CNFs.
Keywords: Nanodielectrics, Dielectric Properties, BT, Nanocomposites, Frequency-Dependent
A significant improvement in fiber-reinforced polymeric composite materials can be obtained by incorporating a very
small amount of nanofillers in the matrix material. In this study, an ultrasonic liquid processor was used to infuse carbon
nanofibers into the polyester matrix which was then mixed with a catalyst using a mechanical agitator. Both conventional
and carbon nanofibers-filled glass fiber-reinforced polyester composites were fabricated using the vacuum-assisted resin
transfer molding process. Low-velocity impact tests was performed at 10 J, 20 J, and 30 J energy levels on conventional as
well as 0.1–0.3 wt% carbon nanofibers-filled glass fiber-reinforced polyester composites using Dynatup8210. The morphology
of fractured specimens was examined using digital photographs and optical microscopy. There was an increase in
the peak load for the nanophased glass fiber-reinforced polyester composites compared with the conventional one. The
absorbed energy of nanophased glass fiber-reinforced polyester composites was less than that of conventional one at
different energy levels. The extent of damage was more pronounced in the conventional glass fiber-reinforced polyester
composites compared to nanophased ones. Failure mechanisms comprised of indentation, debonding, delamination,
matrix cracking, and fiber fracture. The extent of damage was pronounced in conventional composite compared to
nanophased ones.
Keywords
CNF, fiber-reinforced composites, VARTM, low-velocity impact
more concerned about quality today. Customers nowadays are very choosy for
spending money. Quality product or service is their first and foremost
preference. For a service provider, the challenge is to tune up their service with
all desirable qualities so that the customers’ expectations are met. This paper
focuses on the application of quality function deployment on a utility service
company to improve its quality of service through designing the house of
quality matrix. The objective of this work is to provide the case company:
DESCO that distributes and commercialises electrical energy with a
methodology that allows them to identify the focal point of their organisation.
This should also determine on which processes, customer service channels or
other services, they should concentrate in order to satisfy their customer’s
expectations while continuously improving quality.
Keywords: quality function deployment; QFD; utility service; house of
quality; HOQ; voice of customer; VOC.
A high intensity ultrasonic liquid processor was used to infuse 0.1–0.4 wt.% carbon nanofibers (CNFs) into
the polyester matrix which was then mixed with a catalyst using a high speed mechanical agitator. Both
conventional and nanophased glass fiber reinforced polyester composites (GRPCs) were fabricated using
the vacuum assisted resin transfer molding (VARTM) process. Scanning electron microscope (SEM)
revealed best dispersion of CNFs in the 0.2 wt.% CNF-loaded resin. Proper resin flow and impregnation
of the glass fibers were also seen in the SEM micrographs. DMA studies exhibited about 49.5% increase
in the storage modulus and about 3 C increase in the glass transition temperature (Tg) due to the incorporation
of CNFs into the GRPC. TMA studies also showed better thermal stability and lower thermal
expansion in the CNF-loaded GRPC. CNF-loaded GRPC showed higher ILSS due to better interfacial
bonding between the fiber and matrix due to the presence of CNFs. Fracture morphology studied by both
optical microscope (OM) and SEM revealed better interfacial bonding in the CNF-loaded GRPC.
0.2 wt.% CNF infused in polyester, resulting in enhanced mechanical responses. Polyester with 0.2 wt.% CNF samples resulted in 88% and 16% increase in flexural strength and modulus, respectively, over the neat one. Quasi-static compression tests showed similar increasing trend with addition of CNF. Fracture morphology study of tested samples
revealed relatively rougher surface in CNF-loaded polyester compared to the neat due to better interaction between the fiber and the matrix. Dynamic mechanical analysis (DMA)
study exhibited about 35% increase in the storage modulus and about 5 C increase in the glass transition temperature (Tg). A better thermal stability in the CNF-loaded polyester was observed from the thermogravimetric analysis (TGA) studies. Best results were obtained for the 0.2 wt.% CNF loading with 90 mins of sonication and 50% sonication amplitude. It is recommended that this level of sonication facilitates suitable dispersion of the CNF into polyester matrices without destroying the CNF’s structure.
temperature ferroelectricity is attainable under the right processing conditions. When the frequency is increased to 500 Hz, the coercive field also increases, until the frequency reaches 5 kHz, at which point the electric field versus electric displacement becomes linear indicating the limit of domain
switching at high frequency.
frequency-dependent dielectric properties of such a material system with high energy density have
been investigated as functions of the volume fraction of the nanoparticles at room temperature by several
theoretical models. For single domain and single crystals of BT, a Debye type of dissipation and soft mode
theory have been adopted to obtain a more precise frequency-dependent dielectric spectrum of BT. For nanodielectric
composites, among the others, Wiener Rule, Lichtenecker model, Maxwell–Wagner model, Yamada,
andmodified Kernermodel were applied to evaluate the frequency-dependent dielectric spectrum of nanocomposites.
A simple rule of mixture for the dielectric loss tangent was obtained using Lichtenecker logarithmic
rule. The results from theoretical calculations are compared with the experimental data. For the dielectric
constant, Lichtenecker model, Maxwell–Wagner model, and Yamada model show reasonable agreements with
the experimental data up to 50% volume fraction of the nanoparticles. At the higher volume fraction of the
nanoparticles, the experimental data show a decreasing trend of the dielectric constant of the composites due
to an increase in porosity of the system. In this case, a three-phase model (nanoparticles/pores/matrix) was
developed to predict dielectric properties of the system at higher volume fraction of the nanoparticles (up to
80 %). The results showed reasonable agreements for a wide range of frequency. This theoretical study provides
an essential information on dielectric properties of polymer-based BT nanocomposites with a wide frequency
range instead of the trial-and-error strategy of experiments and can be used for designing high energy density
dielectric materials in the future.
incorporating a very small amount of nanofiller in the matrix material. In this work, an ultrasonic liquid
processor was used to infuse carbon nanofiber (CNF) into the polyester matrix which was then mixed
with catalyst using a mechanical agitator. Both conventional and CNF-filled glass-fiber reinforced polyester
composites (GRPC) were fabricated using the vacuum assisted resin transfer molding (VARTM) process.
Excellent dispersion of CNFs into the polyester resin was observed from the scanning electron
microscopy (SEM) micrographs. Flexural and quasi-static tests were performed for investigating the
mechanical responses. Fracture surface was examined using optical microscopy (OM) and SEM. Flexure
tests performed on the conventional GRPC, 0.1–0.4 wt.% CNF-filled GRPC showed up to 49% and 31%
increase in the flexural strength and modulus, respectively, compared to the conventional one with
increasing loading of CNFs up to 0.2 wt.%. Similar trend was seen in quasi-static compression properties.
SEM evaluation revealed relatively less damage in the tested fracture surfaces of the nanophased composites
in terms of matrix failure, fiber breakage, matrix–fiber debonding, and delamination, compared
to the conventional one. This might be the result of better interfacial interaction between matrix and
fibers, due to the presence of CNFs.
Keywords: Nanodielectrics, Dielectric Properties, BT, Nanocomposites, Frequency-Dependent
A significant improvement in fiber-reinforced polymeric composite materials can be obtained by incorporating a very
small amount of nanofillers in the matrix material. In this study, an ultrasonic liquid processor was used to infuse carbon
nanofibers into the polyester matrix which was then mixed with a catalyst using a mechanical agitator. Both conventional
and carbon nanofibers-filled glass fiber-reinforced polyester composites were fabricated using the vacuum-assisted resin
transfer molding process. Low-velocity impact tests was performed at 10 J, 20 J, and 30 J energy levels on conventional as
well as 0.1–0.3 wt% carbon nanofibers-filled glass fiber-reinforced polyester composites using Dynatup8210. The morphology
of fractured specimens was examined using digital photographs and optical microscopy. There was an increase in
the peak load for the nanophased glass fiber-reinforced polyester composites compared with the conventional one. The
absorbed energy of nanophased glass fiber-reinforced polyester composites was less than that of conventional one at
different energy levels. The extent of damage was more pronounced in the conventional glass fiber-reinforced polyester
composites compared to nanophased ones. Failure mechanisms comprised of indentation, debonding, delamination,
matrix cracking, and fiber fracture. The extent of damage was pronounced in conventional composite compared to
nanophased ones.
Keywords
CNF, fiber-reinforced composites, VARTM, low-velocity impact
more concerned about quality today. Customers nowadays are very choosy for
spending money. Quality product or service is their first and foremost
preference. For a service provider, the challenge is to tune up their service with
all desirable qualities so that the customers’ expectations are met. This paper
focuses on the application of quality function deployment on a utility service
company to improve its quality of service through designing the house of
quality matrix. The objective of this work is to provide the case company:
DESCO that distributes and commercialises electrical energy with a
methodology that allows them to identify the focal point of their organisation.
This should also determine on which processes, customer service channels or
other services, they should concentrate in order to satisfy their customer’s
expectations while continuously improving quality.
Keywords: quality function deployment; QFD; utility service; house of
quality; HOQ; voice of customer; VOC.
A high intensity ultrasonic liquid processor was used to infuse 0.1–0.4 wt.% carbon nanofibers (CNFs) into
the polyester matrix which was then mixed with a catalyst using a high speed mechanical agitator. Both
conventional and nanophased glass fiber reinforced polyester composites (GRPCs) were fabricated using
the vacuum assisted resin transfer molding (VARTM) process. Scanning electron microscope (SEM)
revealed best dispersion of CNFs in the 0.2 wt.% CNF-loaded resin. Proper resin flow and impregnation
of the glass fibers were also seen in the SEM micrographs. DMA studies exhibited about 49.5% increase
in the storage modulus and about 3 C increase in the glass transition temperature (Tg) due to the incorporation
of CNFs into the GRPC. TMA studies also showed better thermal stability and lower thermal
expansion in the CNF-loaded GRPC. CNF-loaded GRPC showed higher ILSS due to better interfacial
bonding between the fiber and matrix due to the presence of CNFs. Fracture morphology studied by both
optical microscope (OM) and SEM revealed better interfacial bonding in the CNF-loaded GRPC.