Abstract: The systematic manipulations of shapes and sizes of
inorganic compounds greatly benefit the various application fields
including optics, magnetic, electronics, catalysis and medicine.
However shape control has been much more difficult to achieve.
Hence exploration of novel method for the preparation of differently
shaped nanoparticles is challenging research area. II-VI group of
semiconductor cadmium sulphide (CdS) nanostructure with different
morphologies (such as, acicular like, mesoporous, spherical shapes)
and of crystallite sizes vary from 11 to 16 nm were successfully
synthesized by chemical aqueous precipitation of Cd2+ ions with
homogeneously released S2- ions from decomposition of cadmium
sulphate (CdSO4) and thioacetamide (CH3CSNH2) by annealing at
different radiations (microwave, ultrasonic and sunlight) with matter
and systematic research has been done for various factors affecting
the controlled growth rate of CdS nanoparticles. The obtained
nanomaterials have been characterized by X-ray Diffraction (XRD),
Fourier Transform Infrared Spectroscopy (FTIR),
Thermogravometric (DSC-TGA) analysis and Scanning Electron
Microscopy (SEM). The result indicates that on increasing the
reaction time particle size increases but on increasing the molar ratios
grain size decreases.
Abstract: This paper describes the design and fabrication of a clock and data recovery circuit (CDR). We propose a new clock and data recovery which is based on a 1/4-rate frequency detector (QRFD). The proposed frequency detector helps reduce the VCO frequency and is thus advantageous for high speed application. The proposed frequency detector can achieve low jitter operation and extend the pull-in range without using the reference clock. The proposed CDR was implemented using a 1/4-rate bang-bang type phase detector (PD) and a ring voltage controlled oscillator (VCO). The CDR circuit has been fabricated in a standard 0.18 CMOS technology. It occupies an active area of 1 x 1 and consumes 90 mW from a single 1.8V supply.
Abstract: Carbon fibers are fabricated from different materials,
such as special polyacrylonitrile (PAN) fibers, rayon fibers and pitch.
Among these three groups of materials, PAN fibers are the most
widely used precursor for the manufacture of carbon fibers. The
process of fabrication carbon fibers from special PAN fibers includes
two steps; oxidative stabilization at low temperature and
carbonization at high temperatures in an inert atmosphere. Due to the
high price of raw materials (special PAN fibers), carbon fibers are
still expensive.
In the present work the main goal is making carbon fibers from
low price commercial PAN fibers with modified chemical
compositions. The results show that in case of conducting completes
stabilization process, it is possible to produce carbon fibers with
desirable tensile strength from this type of PAN fibers. To this
matter, thermal characteristics of commercial PAN fibers were
investigated and based upon the obtained results, with some changes
in conventional procedure of stabilization in terms of temperature
and time variables; the desirable conditions of complete stabilization
is achieved.
Abstract: n-CdO/p-Si heterojunction diode was fabricated using
sol-gel spin coating technique which is a low cost and easily scalable
method for preparing of semiconductor films. The structural and
morphological properties of CdO film were investigated. The X-ray
diffraction (XRD) spectra indicated that the film was of
polycrystalline nature. The scanning electron microscopy (SEM)
images indicate that the surface morphology CdO film consists of the
clusters formed with the coming together of the nanoparticles. The
electrical characterization of Au/n-CdO/p–Si/Al heterojunction diode
was investigated by current-voltage. The ideality factor of the diode
was found to be 3.02 for room temperature. The reverse current of
the diode strongly increased with illumination intensity of 100
mWcm-2 and the diode gave a maximum open circuit voltage Voc of
0.04 V and short-circuits current Isc of 9.92×10-9 A.
Abstract: This paper reports on the results of experimental investigations on the performance of a jet pump operated under selected primary flows to optimize the related parameters. For this purpose a two-phase flow jet pump was used employing various profiles of nozzles as the primary device which was designed, fabricated and used along with the combination of mixing tube and diffuser. The profiles employed were circular, conical, and elliptical. The diameter of the nozzle used was 4 mm. The area ratio of the jet pump was 0.16. The test facility created for this purpose was an open loop continuous circulation system. Performance of the jet pump was obtained as iso-efficiency curves on characteristic curves drawn for various water flow rates. To perform the suction capability, evacuation test was conducted at best efficiency point for all the profiles.
Abstract: Localized surface plasmon resonance (LSPR) is the
coherent oscillation of conductive electrons confined in noble
metallic nanoparticles excited by electromagnetic radiation, and
nanosphere lithography (NSL) is one of the cost-effective methods to
fabricate metal nanostructures for LSPR. NSL can be categorized
into two major groups: dispersed NSL and closely pack NSL. In
recent years, gold nanocrescents and gold nanoholes with vertical
sidewalls fabricated by dispersed NSL, and silver nanotriangles and
gold nanocaps on silica nanospheres fabricated by closely pack NSL,
have been reported for LSPR biosensing. This paper introduces
several novel gold nanostructures fabricated by NSL in LSPR
applications, including 3D nanostructures obtained by evaporating
gold obliquely on dispersed nanospheres, nanoholes with slant
sidewalls, and patchy nanoparticles on closely packed nanospheres,
all of which render satisfactory sensitivity for LSPR sensing. Since
the LSPR spectrum is very sensitive to the shape of the metal
nanostructures, formulas are derived and software is developed for
calculating the profiles of the obtainable metal nanostructures by
NSL, for different nanosphere masks with different fabrication
conditions. The simulated profiles coincide well with the profiles of
the fabricated gold nanostructures observed under scanning electron
microscope (SEM) and atomic force microscope (AFM), which
proves that the software is a useful tool for the process design of
different LSPR nanostructures.
Abstract: Fabrication and efficiency enhancement of non-mercury, high efficiency and green field emission lamps using carbon nano-materials such as carbon nanotubes as cathode field emitters was studied. Phosphor was coated on the ITO glass or metal substrates as the anode. The luminescence efficiency enhancement was carried out by upgrading the uniform of the emitters, improving electron and thermal conductivity of the phosphor and the optimization of the design of different cathode/anode configurations. After evaluation of the aforementioned parameters, the luminescence efficiency of the field emission lamps was raised.
Abstract: This paper deals with a novel technique for the
fabrication of Spiral grooves in a dynamic thrust bearing. The main
scheme proposed in this paper is to fabricate the microgrooves using
desktop forming system. This process has advantages compared to the
conventional electro-chemical machining in the viewpoint of a higher
productivity. For this reason, a new testing apparatus is designed and
built for press forming microgrooves on a surface of the thrust bearing.
The material used in this study is sintered Cu-Fe alloy. The effects of
the forming load on the performance of micro press forming are
experimentally investigated. From the experimental results, formed
depths are closed to the target ones with increasing the forming load.
Abstract: Highly ordered TiO2 nanotube (TNT) arrays were
fabricated onto a pre-treated titanium foil by anodic oxidation with a
voltage of 20V in phosphoric acid/sodium fluoride electrolyte. A pretreatment
of titanium foil involved washing with acetone,
isopropanol, ethanol and deionized water. Carbon doped TiO2
nanotubes (C-TNT) was fabricated 'in-situ' with the same method in
the presence of polyvinyl alcohol and urea as carbon sources. The
affects of polyvinyl alcohol concentration and oxidation time on the
composition, morphology and structure of the C-TN were studied by
FE-SEM, EDX and XRD techniques. FESEM images of the
nanotubes showed uniform arrays of C-TNTs. The density and
microstructures of the nanotubes were greatly affected by the content
of PVA. The introduction of the polyvinyl alcohol into the electrolyte
increases the amount of C content inside TiO2 nanotube arrays
uniformly. The influence of carbon content on the photo-current of
C-TNT was investigated and the I-V profiles of the nanotubes were
established. The preliminary results indicated that the 'in-situ'
doping technique produced a superior quality nanotubes compared to
post doping techniques.
Abstract: The study describes chitosan membrane platform
modified with nanostructure pattern which using nanotechnology to
fabricate. The cell-substrate interaction between neuro-2a neuroblasts
cell lines and chitosan membrane (flat, nanostructure and
nanostructure pattern types) was investigated. The adhered
morphology of neuro-2a cells depends on the topography of chitosan
surface. We have found that neuro-2a showed different morphogenesis
when cells adhered on flat and nanostructure chitosan membrane. The
cell projected area of neuro-2a on flat chitosan membrane is larger
than on nanostructure chitosan membrane. In addition, neuro-2a cells
preferred to adhere on flat chitosan surface region than on
nanostructure chitosan membrane to immobilize and differentiation.
The experiment suggests surface topography can be used as a critical
mechanism to isolate group of neuro-2a to a particular rectangle area
on chitosan membrane. Our finding will provide a platform to take
patch clamp to record electrophysiological behavior about neurons in
vitro in the future.
Abstract: Rapid prototyping (RP) techniques are a group of
advanced manufacturing processes that can produce custom made
objects directly from computer data such as Computer Aided Design
(CAD), Computed Tomography (CT) and Magnetic Resonance
Imaging (MRI) data. Using RP fabrication techniques, constructs
with controllable and complex internal architecture with appropriate
mechanical properties can be achieved. One of the attractive and
promising utilization of RP techniques is related to tissue engineering
(TE) scaffold fabrication. Tissue engineering scaffold is a 3D
construction that acts as a template for tissue regeneration. Although
several conventional techniques such as solvent casting and gas
forming are utilized in scaffold fabrication; these processes show
poor interconnectivity and uncontrollable porosity of the produced
scaffolds. So, RP techniques become the best alternative fabrication
methods of TE scaffolds. This paper reviews the current state of the
art in the area of tissue engineering scaffolds fabrication using
advanced RP processes, as well as the current limitations and future
trends in scaffold fabrication RP techniques.
Abstract: A new paradigm for software design and development models software by its business process, translates the model into a process execution language, and has it run by a supporting execution engine. This process-oriented paradigm promotes modeling of software by less technical users or business analysts as well as rapid development. Since business process models may be shared by different organizations and sometimes even by different business domains, it is interesting to apply a technique used in traditional software component technology to design reusable business processes. This paper discusses an approach to apply a technique for software component fabrication to the design of process-oriented software units, called process components. These process components result from decomposing a business process of a particular application domain into subprocesses with an aim that the process components can be reusable in different process-based software models. The approach is quantitative because the quality of process component design is measured from technical features of the process components. The approach is also strategic because the measured quality is determined against business-oriented component management goals. A software tool has been developed to measure how good a process component design is, according to the required managerial goals and comparing to other designs. We also discuss how we benefit from reusable process components.
Abstract: The paper aims to show that implementing different
types of reflectors in solar energy systems, will dramatically improve
energy production by means of concentrating and intensifying more
sunlight onto a solar cell. The Solar Intensifier unit is designed to
increase efficiency and performance of a set of solar panels. The unit
was fabricated and tested. The experimental results show good
improvement in the performance of the solar energy system.
Abstract: pH-sensitive drug targeting using nanoparticles for
cancer chemotherapy have been spotlighted in recent decades. Graft
copolymer composed of poly (L-histidine) (PHS) and dextran
(DexPHS) was synthesized and pH-sensitive nanoparticles were
fabricated for pH-responsive drug delivery of doxorubicin (DOX).
Nanoparticles of DexPHS showed pH-sensitive changes in particle
sizes and drug release behavior, i.e. particle sizes and drug release rate
were increased at acidic pH, indicating that DexPHS nanoparticles
have pH-sensitive drug delivery potentials. Antitumor activity of
DOX-incorporated DexPHS nanoparticles were studied using CT26
colorectal carcinoma cells. Results indicated that fluorescence
intensity was higher at acidic pH than basic pH. These results
indicated that DexPHS nanoparticles have pH-responsive drug
targeting.
Abstract: A way of generating millimeter wave I/Q signal using inductive resonator matched poly-phase filter is suggested. Normally the poly-phase filter generates quite accurate I/Q phase and magnitude but the loss of the filter is considerable due to series connection of passive RC components. This loss term directly increases system noise figure when the poly-phase filter is used in RF Front-end. The proposed matching method eliminates above mentioned loss and in addition provides gain on the passive filter. The working algorithm is illustrated by mathematical analysis. The generated I/Q signal is used in implementing millimeter wave phase shifter for the 60 GHz communication system to verify its effectiveness. The circuit is fabricated in 90 nm TSMC RF CMOS process under 1.2 V supply voltage. The measurement results showed that the suggested method improved gain by 6.5 dB and noise by 2.3 dB. The summary of the proposed I/Q generation is compared with previous works.
Abstract: This paper presents the results of the experimental
tests of the cooling performance of a 12,000-Btu/h modified air
conditioner (referred to as M-AC) that use the ground as a heat sink
of a condenser. In the tests, cooling capacity of M-AC with an
optimal length of a condensing coil as well as life expectancy of
copper coil buried underground were investigated. The lengths of
copper coil fabricated and used as condenser coil of M-AC were set
at 67, 50, 40 and 30 m whereas that of a 12,000-Btu/h conventional
split-type air conditioner (referred to as C-AC) was about 22 m. The
results showed that the ground can absorb heat rejected from a
condenser of M-AC. The coefficient of performance (COP) of C-AC
was about 2.5 whereas those of M-AC were found to be higher. It
was found that the values of COP of M-AC with condensing coils of
67, 50 and 40 m long were about 6.9, 5.5 and 3.3, respectively, while
that of 30-m-long one was found to be about 2.1. The electrical
consumptions of M-AC were found lower than that of C-AC in the
range of 11.5 – 15.5%. Additionally, life expectancy of underground
condensing coil of M-AC was found to be over 7 years.
Abstract: A simple mobile engine-driven pneumatic paddy
collector made of locally available materials using local
manufacturing technology was designed, fabricated, and tested for
collecting and bagging of paddy dried on concrete pavement. The
pneumatic paddy collector had the following major components:
radial flat bladed type centrifugal fan, power transmission system,
bagging area, frame and the conveyance system. Results showed
significant differences on the collecting capacity, noise level, and fuel
consumption when rotational speed of the air mover shaft was varied.
Other parameters such as collecting efficiency, air velocity,
augmented cracked grain percentage, and germination rate were not
significantly affected by varying rotational speed of the air mover
shaft. The pneumatic paddy collector had a collecting efficiency of
99.33 % with a collecting capacity of 2685.00 kg/h at maximum
rotational speed of centrifugal fan shaft of about 4200 rpm. The
machine entailed an investment cost of P 62,829.25. The break-even
weight of paddy was 510,606.75 kg/yr at a collecting cost of 0.11
P/kg of paddy. Utilizing the machine for 400 hours per year
generated an income of P 23,887.73. The projected time needed to
recover cost of the machine based on 2685 kg/h collecting capacity
was 2.63 year.
Abstract: This paper presents a experiment to estimate the
influences of cutting conditions in microstructure changes of
machining austenitic 304 stainless steel, especially for wear insert. The
wear insert were prefabricated with a width of 0.5 mm. And the forces,
temperature distribution, RS, and microstructure changes were
measured by force dynamometer, infrared thermal camera, X-ray
diffraction, XRD, SEM, respectively. The results told that the different
combinations of machining condition have a significant influence on
machined surface microstructure changes. In addition to that, the
ANOVA and AOMwere used to tell the different influences of cutting
speed, feed rate, and wear insert.
Abstract: The power consumption of an Optical Packet Switch
equipped with SOA technology based Spanke switching fabric is
evaluated. Sophisticated analytical models are introduced to evaluate
the power consumption versus the offered traffic, the main
switch parameters, and the used device characteristics. The impact
of Amplifier Spontaneous Emission (ASE) noise generated by a
transmission system on the power consumption is investigated. As
a matter of example for 32×32 switches supporting 64 wavelengths
and offered traffic equal to 0,8, the average energy consumption per
bit is 5, 07 · 10-2 nJ/bit and increases if ASE noise introduced by
the transmission systems is increased.
Abstract: Personal name matching system is the core of
essential task in national citizen database, text and web mining,
information retrieval, online library system, e-commerce and record
linkage system. It has necessitated to the all embracing research in
the vicinity of name matching. Traditional name matching methods
are suitable for English and other Latin based language. Asian
languages which have no word boundary such as Myanmar language
still requires sounds alike matching system in Unicode based
application. Hence we proposed matching algorithm to get analogous
sounds alike (phonetic) pattern that is convenient for Myanmar
character spelling. According to the nature of Myanmar character, we
consider for word boundary fragmentation, collation of character.
Thus we use pattern conversion algorithm which fabricates words in
pattern with fragmented and collated. We create the Myanmar sounds
alike phonetic group to help in the phonetic matching. The
experimental results show that fragmentation accuracy in 99.32% and
processing time in 1.72 ms.