Abstract: The main objective of this research is to synthesize silk fibroin fiber for indoor air particulate removal. Silk cocoons were de-gummed using 0.5 wt % Na2CO3 alkaline solutions at 90 Ó╣ìC for 60 mins, washed with distilled water, and dried at 80 Ó╣ìC for 3 hrs in a vacuum oven. Two sets of experiment were conducted to investigate the impacts of initial particulate matter (PM) concentration and that of air flow rate on the removal efficiency. Rice bran collected from a local rice mill in Ubonratchathani province was used as indoor air contaminant in this work. The morphology and physical properties of silk fibroin (SF) fiber were measured. The SEM revealed the deposition of PM on the used fiber. The PM removal efficiencies of 72.29 ± 3.03 % and 39.33 ± 1.99 % were obtained of PM10 and PM2.5, respectively, when using the initial PM concentration at 0.040 mg/m3 and 0.020 mg/m3 of PM10 and PM2.5, respectively, with the air flow rate of 5 L/min.
Abstract: This paper solves the Non Linear Schrodinger
Equation using the Split Step Fourier method for modeling an optical
fiber. The model generates a complex wave of optical pulses and
using the results obtained two graphs namely Loss versus
Wavelength and Dispersion versus Wavelength are generated. Taking
Chromatic Dispersion and Polarization Mode Dispersion losses into
account, the graphs generated are compared with the graphs
formulated by JDS Uniphase Corporation which uses standard values
of dispersion for optical fibers. The graphs generated when compared
with the JDS Uniphase Corporation plots were found to be more or
less similar thus verifying that the model proposed is right.
MATLAB software was used for doing the modeling.
Abstract: Optical networks are high capacity networks that meet
the rapidly growing demand for bandwidth in the terrestrial
telecommunications industry. This paper studies and evaluates singlemode
and multimode fiber transmission by varying the distance. It
focuses on their performance in LAN environment. This is achieved
by observing the pulse spreading and attenuation in optical spectrum
and eye-diagram that are obtained using OptSim simulator. The
behaviors of two modes with different distance of data transmission
are studied, evaluated and compared.
Abstract: An optical fault monitoring in FTTH-PON using ACS
is demonstrated. This device can achieve real-time fault monitoring
for protection feeder fiber. In addition, the ACS can distinguish
optical fiber fault from the transmission services to other customers
in the FTTH-PON. It is essential to use a wavelength different from
the triple-play services operating wavelengths for failure detection.
ACS is using the operating wavelength 1625 nm for monitoring and
failure detection control. Our solution works on a standard local area
network (LAN) using a specially designed hardware interfaced with a
microcontroller integrated Ethernet.
Abstract: In this paper, a post processing scheme is suggested
for improvement of Bit Error-Rate (BER) in optical fiber
transmission receivers. The developed scheme has been tested on
optical fiber systems operating with a non-return-to-zero (NRZ)
format at transmission rates of up to 10Gbps. The transmission
system considered is based on well known transmitters and receivers
blocks operating at wavelengths in the region of 1550 nm using a
standard single mode fiber. Performance of improved detected
signals has been evaluated via the analysis of quality factor and
computed bit error rates. Numerical simulations have shown a
noticeable improvement of the system BER after implementation of
the suggested post processing operation on the detected electrical
signals.
Abstract: The nanofiber sheet of Multiwall Cabon Nanotube
(MWCNTs)/Polyacylonitile (PAN) composites was fabricated from
electrospun nanofiber. Firstly the surface of MWCNTs was
chemically modified, comparing two different techniques consisting
of admicellar polymerization and functionalization to improve the
dispersion and prevent the aggregation in the PAN matrix. The
modified MWCNTs were characterized by the dispersion in
dimethylformamide (DMF) solvent, Laser particle size, and FTRaman.
Lastly, DSC, SEM and mechanical properties of the
nanofiber sheet were examined. The results show that the mechanical
properties of the nanofiber sheet prepared from admicellar
polymerization-modified MWCNTs were higher than those of the
others.
Abstract: Environmental awareness and depletion of the
petroleum resources are among vital factors that motivate a number
of researchers to explore the potential of reusing natural fiber as an
alternative composite material in industries such as packaging,
automotive and building constructions. Natural fibers are available in
abundance, low cost, lightweight polymer composite and most
importance its biodegradability features, which often called “ecofriendly"
materials. However, their applications are still limited due
to several factors like moisture absorption, poor wettability and large
scattering in mechanical properties. Among the main challenges on
natural fibers reinforced matrices composite is their inclination to
entangle and form fibers agglomerates during processing due to
fiber-fiber interaction. This tends to prevent better dispersion of the
fibers into the matrix, resulting in poor interfacial adhesion between
the hydrophobic matrix and the hydrophilic reinforced natural fiber.
Therefore, to overcome this challenge, fiber treatment process is one
common alternative that can be use to modify the fiber surface
topology by chemically, physically or mechanically technique.
Nevertheless, this paper attempt to focus on the effect of
mercerization treatment on mechanical properties enhancement of
natural fiber reinforced composite or so-called bio composite. It
specifically discussed on mercerization parameters, and natural fiber
reinforced composite mechanical properties enhancement.
Abstract: Renewable water resources are crucial production
variables in arid and semi-arid regions where intensive agriculture is
practiced to meet ever-increasing demand for food and fiber. This is
crucial for the Dez and Moghan command areas where water delivery
problems and adverse environmental issues are widespread. This
paper aims to identify major problems areas using on-farm surveys of
200 farmers, agricultural extensionists and water suppliers which was
complemented by secondary data and field observations during 2010-
2011 cultivating season. The SPSS package was used to analyze and
synthesis data. Results indicated inappropriate canal operations in
both schemes, though there was no unanimity about the underlying
causes. Inequitable and inflexible distribution was found to be rooted
in deficient hydraulic structures particularly in the main and
secondary canals. The inadequacy and inflexibility of water
scheduling regime was the underlying causes of recurring pest and
disease spread which often led to the decline of crop yield and
quality, although these were not disputed, the water suppliers were
not prepared to link with the deficiencies in the operation of the main
and secondary canals. They rather attributed these to the prevailing
salinity; alkalinity, water table fluctuations and leaching of the
valuable agro-chemical inputs from the plants- route zone with farreaching
consequences. Examples of these include the pollution of
ground and surface resources due to over-irrigation at the farm level
which falls under the growers- own responsibility. Poor irrigation
efficiency and adverse environmental problems were attributed to
deficient and outdated farming practices that were in turn rooted in
poor extension programs and irrational water charges.
Abstract: This report shows the performance of composite
biodegradable film from chitosan, starch and sawdust fiber. The main
objectives of this research are to fabricate and characterize composite
biodegradable film in terms of morphology and physical properties.
The film was prepared by casting method. Sawdust fiber was used as
reinforcing agent and starch as polymer matrix in the casting
solution. The morphology of the film was characterized using atomic
force microscope (AFM). The result showed that the film has
smooth structure. Chemical composition of the film was investigated
using Fourier transform infrared (FTIR) where the result revealed
present of starch in the film. The thermal properties were
characterized using thermal gravimetric analyzer (TGA) and
differential scanning calorimetric (DSC) where the results showed
that the film has small difference in melting and degradation
temperature.
Abstract: This paper demonstrates the feasibility of replacing
the metal coil spring with the composite coil spring. Three different
types of springs were made using glass fiber, carbon fiber and
combination of glass fiber and carbon fiber. The objective of the
study is to reduce the weight of the spring. According to the
experimental results the spring rate of the carbon fiber spring is
34% more than the glass fiber spring and 45% more than the glass
fiber/carbon fiber spring. The weight of the carbon fiber spring is
18% less than the glass fiber spring, 15% less than the Glass
fiber/carbon fiber spring and 80% less than the steel spring.
Abstract: In this study, single nozzle method used for
electrospinning technique which composite polymer solution with
cellulose nanowiskers (CNW) was treated by ultrasonic sonificator
have been compared with coaxial (double) nozzle method, in terms of
mechanical, thermal and morphological properties of composite
nanofiber. The effect of water content in composite polymer solution
on properties of nanofiber has also been examined. It has been seen
that single nozzle method which polymer solution does not contain
water has better results than that of coaxial method, in terms of
mechanical, thermal and morphological properties of nanofiber.
However, it is necessary to make an optimization study on setting
condition of ultrasonic treatment to get better dispersion of CNW in
composite nanofiber and to get better mechanical and thermal
properties