Abstract: Overhead electrical insulators form an important link in an electric power system. Along with the traditional insulators (i.e. glass and porcelain, etc) presently the polymeric insulators are also used world widely. These polymeric insulators are very sensitive to various environmental parameters such temperature, environmental pollution, UV-radiations, etc. which seriously effect their electrical, chemical and hydrophobic properties. The UV radiation level in the central region of Saudi Arabia is high as compared to the IEC standard for the accelerated aging of the composite insulators. Commonly used suspension type of composite EPDM (Ethylene Propylene Diene Monomer) insulator was subjected to accelerated stress aging as per modified IEC standard simulating the inland arid deserts atmospheric condition and also as per IEC-61109 standard. The hydrophobic characteristics were studied by measuring the contact angle along the insulator surface before and after the accelerated aging of the samples. It was found that EPDM insulator loses it hydrophobic properties proportional to the intensity of UV irradiations and its rate of recovery is also very low as compared to Silicone Rubber insulator.KeywordsEPDM, composite insulators, accelerated aging, hydrophobicity, contact angle.
Abstract: This paper presents a SCR-based ESD protection devices for I/O clamp and power rail clamp, respectably. These devices have a low trigger voltage and high holding voltage characteristics than conventional SCR device. These devices are fabricated by using 0.35um BCD (Bipolar-CMOS-DMOS) processes. These devices were validated using a TLP system. From the experimental results, the device for I/O ESD clamp has a trigger voltage of 5.8V. Also, the device for power rail ESD clamp has a holding voltage of 7.7V.
Abstract: Materials used on exterior spacecraft surfaces are subjected to many environmental threats which can cause degradation, atomic oxygen is one of the most threats. We prepared organic silicon atomic-oxygen-protection film using method of polymerization. This paper presented the effects on the film structure and its durability of the preparation processing, and analyzed the polymerization theory, the film structure and composition of the film. At last, we tested the film in our ground based atomic oxygen simulator, and indicated that the film worked well.
Abstract: Experiments were carried out at the Latvia State
Institute of Fruit-Growing in 2011. Fresh-cut minimally processed
apple and pear mixed salad were packed by passive modified
atmosphere (MAP) in PP containers, which were hermetically sealed
by breathable conventional BOPP PropafreshTM P2GAF, and Amcor
Agrifresh films. Biodegradable NatureFlexTM NVS INNOVIA Films
and VC999 BioPack PLA films coated with a barrier of pure silicon
oxide (SiOx) were used to compare the fresh-cut produce quality
with this packed in conventional packaging films. Samples were cold
stored at temperature +4.0±0.5 °C up to 10 days. The quality of salad
was evaluated by physicochemical properties – weight losses,
moisture, firmness, the effect of packaging modes on the colour,
dynamics in headspace atmosphere concentration (CO2 and O2),
titratable acidity values, as well as by microbiological contamination
(yeasts, moulds and total bacteria count) of salads, analyzing before
packaging and after 2, 4, 6, 8, and 10 storage days.
Abstract: The “conveyor belt" as a product represents a
complex high performance component with a wide range of different
applications. Further development of these highly complex
components demands an integration of new technologies and new
enhanced materials. In this context nanostructured fillers appear to
have a more promising effect on the performance of the conveyor
belt composite than conventional micro-scaled fillers.
Within the project “DotTrans" nanostructured fillers, for example
silicon dioxide, are used to optimize performance parameters of
conveyor belt systems. The objective of the project includes
operating parameters like energy consumption or friction
characteristics as well as adaptive parameters like cut or wear
resistance.
Abstract: This article summarizes ways to verify neutron
fluence for neutron transmutation doping of silicon with phosphorus
on the LVR-15 reactor. Neutron fluence is determined using
activation detectors placed along the crystal in a strip or encapsulated
in a rod holder. Holders are placed at the centre of a water-filled
capsule or in an aluminum or silicon ingot that simulates a real single
crystal. If the diameter of the crystal is significantly less than the
capsule diameter and water from the primary circuit enters the free
space in the capsule, neutron interaction in the water changes neutron
fluence, affecting axial irradiation homogeneity. The effect of
moving the capsule vertically in the channel relative to maximum
neutron fluence in the reactor core was also measured. Even a small
shift of the capsule-s centre causes great irradiation inhomogeneity.
This effect was measured using activation detectors, and was also
confirmed by MCNP calculation.
Abstract: We present an integration approach of a CMOS biosensor into a polymer based microfluidic environment suitable for mass production. It consists of a wafer-level-package for the silicon die and laser bonding process promoted by an intermediate hot melt foil to attach the sensor package to the microfluidic chip, without the need for dispensing of glues or underfiller. A very good condition of the sensing area was obtained after introducing a protection layer during packaging. A microfluidic flow cell was fabricated and shown to withstand pressures up to Δp = 780 kPa without leakage. The employed biosensors were electrically characterized in a dry environment.
Abstract: The use of synthetic retardants in polymeric insulated
cables is not uncommon in the high voltage engineering to study
electrical treeing phenomenon. However few studies on organic
materials for the same investigation have been carried. .This paper
describes the study on the effects of Oil Palm Empty Fruit Bunch
(OPEFB) microfiller on the tree initiation and propagation in silicone
rubber with different weight percentages (wt %) of filler to insulation
bulk material. The weight percentages used were 0 wt % and 1 wt %
respectively. It was found that the OPEFB retards the propagation of
the electrical treeing development. For tree inception study, the
addition of 1(wt %) OPEFB has increase the tree inception voltage of
silicone rubber. So, OPEFB is a potential retardant to the initiation
and growth of electrical treeing occurring in polymeric materials for
high voltage application. However more studies on the effects of
physical and electrical properties of OPEFB as a tree retardant
material are required.
Abstract: A major challenge in biomaterials research is the
regulation of protein adsorption which is a key factor for controlling
the subsequent cell adhesion at implant surfaces. The aim of the
present study was to control the adsorption of fibronectin (FN) and
the attachment of MG-63 osteoblasts with an electronic
nanostructure. Shallow doping line lattices with a period of 260 nm
were produced for this purpose by implantation of phosphorous in
silicon wafers. Protein coverage was determined after incubating the
substrate with FN by means of an immunostaining procedure and the
measurement of the fluorescence intensity with a TECAN analyzer.
We observed an increased amount of adsorbed FN on the
nanostructure compared to control substrates. MG-63 osteoblasts
were cultivated for 24h on FN-incubated substrates and their
morphology was assessed by SEM. Preferred orientation and
elongation of the cells in direction of the doping lattice lines was
observed on FN-coated nanostructures.
Abstract: The carbon based coils with the nanometer scale have
the 3 dimension helix geometry. We synthesized the carbon nano-coils
by the use of chemical vapor deposition technique with iron and tin as
the catalysts. The fabricated coils have the external diameter of
ranging few hundred nm to few thousand nm. The Scanning
Electro-Microscope (SEM) and Tunneling Electro-Microscope has
shown detail images of the coil-s structure. The fabrication of the
carbon nano-coils can be grown on the metal and non-metal substrates,
such as the stainless steel and silicon substrates. Besides growth on the
flat substrate; they also can be grown on the stainless steel wires. After
the synthesis of the coils, the mechanical and electro-mechanical
property is measured. The experimental results were reported.
Abstract: This research focuses on the effect of weight
percentage variation and size variation of MgFeSi added,
gating system design and reaction chamber design on inmold
process. By using inmold process, well-known problem of
fading is avoided because the liquid iron reacts with
magnesium in the mold and not, as usual, in the ladle. During
the pouring operation, liquid metal passes through the
chamber containing the magnesium, where the reaction of the
metal with magnesium proceeds in the absence of atmospheric
oxygen [1].In this paper, the results of microstructural
characteristic of ductile iron on this parameters are mentioned.
The mechanisms of the inmold process are also described [2].
The data obtained from this research will assist in producing
the vehicle parts and other machinery parts for different
industrial zones and government industries and in transferring
the technology to all industrial zones in Myanmar. Therefore,
the inmold technology offers many advantages over traditional
treatment methods both from a technical and environmental,
as well as an economical point of view. The main objective of
this research is to produce ductile iron castings in all industrial
sectors in Myanmar more easily with lower costs. It will also
assist the sharing of knowledge and experience related to the
ductile iron production.
Abstract: It is well known that the abrasive particles in the
abrasive water suspension has significant effect on the erosion
characteristics of the inside surface of the nozzle. Abrasive particles
moving with the flow cause severe skin friction effect, there by
altering the nozzle diameter due to wear which in turn reflects on the
life of the nozzle for effective machining. Various commercial
abrasives are available for abrasive water jet machining. The erosion
characteristic of each abrasive is different. In consideration of this
aspect, in the present work, the effect of abrasive materials namely
garnet, aluminum oxide and silicon carbide on skin friction
coefficient due to wall shear stress and jet kinetic energy has been
analyzed. It is found that the abrasive material of lower density
produces a relatively higher skin friction effect and higher jet exit
kinetic energy.
Abstract: This paper presents a vertical silicon nanowire n- MOSFET integrated with a CMOS-compatible fully-silicided (FUSI) NiSi2 gate. Devices with nanowire diameter of 50nm show good electrical performance (SS < 70mV/dec, DIBL < 30mV/V, Ion/Ioff > 107). Most significantly, threshold voltage tunability of about 0.2V is shown. Although threshold voltage remains low for the 50nm diameter device, it is expected to become more positive as nanowire diameter reduces.
Abstract: In the Fe-3%Si sheets, grade Hi-B, with AlN and MnS
as inhibitors, the Goss grains which abnormally grow do not have a
size greater than the average size of the primary matrix. In this
heterogeneous microstructure, the size factor is not a required
condition for the secondary recrystallization. The onset of the small
Goss grain abnormal growth appears to be related to a particular
behavior of their grain boundaries, to the local texture and to the
distribution of the inhibitors. The presence and the evolution of
oriented clusters ensure to the small Goss grains a favorable
neighborhood to grow. The modified Monte-Carlo approach, which
is applied, considers the local environment of each grain. The grain
growth is dependent of its real spatial position; the matrix
heterogeneity is then taken into account. The grain growth conditions
are considered in the global matrix and in different matrixes
corresponding to A component clusters. The grain growth behaviour
is considered with introduction of energy only, energy and mobility,
energy and mobility and precipitates.
Abstract: We investigated a modified thermal evaporation
method in the growth process of ZnO nanowires. ZnO nanowires
were fabricated on p-type silicon substrates without using a metal
catalyst. A simple horizontal double-tube system along with
chemical vapor diffusion of the precursor was used to grow the ZnO
nanowires. The substrates were placed in different temperature
zones, and ZnO nanowires with different diameters were obtained for
the different substrate temperatures. In addition to the nanowires,
ZnO microdiscs with different diameters were obtained on another
substrate, which was placed at a lower temperature than the other
substrates. The optical properties and crystalline quality of the ZnO
nanowires and microdiscs were characterized by room temperature
photoluminescence (PL) and Raman spectrometers. The PL and
Raman studies demonstrated that the ZnO nanowires and microdiscs
grown using such set-up had good crystallinity with excellent optical
properties. Rectifying behavior of ZnO/Si heterostructures was
characterized by a simple DC circuit.
Abstract: As application of re-activation of backside on power
device Insulated Gate Bipolar Transistor (IGBT), laser annealing was
employed to irradiate amorphous silicon substrate, and resistivities
were measured using four point probe measurement. For annealing
the amorphous silicon two lasers were used at wavelength of visible
green (532 nm) together with Infrared (793 nm). While the green
laser efficiently increased temperature at top surface the Infrared
laser reached more deep inside and was effective for melting the
top surface. A finite element method was employed to evaluate time
dependent thermal distribution in silicon substrate.
Abstract: This paper presents a silicon controller rectifier (SCR)
based ESD protection circuit for IC. The proposed ESD protection
circuit has low trigger voltage and high holding voltage compared with
conventional SCR ESD protection circuit. Electrical characteristics of
the proposed ESD protection circuit are simulated and analyzed using
TCAD simulator. The proposed ESD protection circuit verified
effective low voltage ESD characteristics with low trigger voltage and
high holding voltage.
Abstract: Materials added to the matrix help improving operating properties of a composite. This experimental study has targeted to investigate this aim where Silicon Oxide particles were added to glass fibre and epoxy resin at an amount of 15% to the main material to obtain a sort of new composite material. Erosive wear behavior of epoxy-resin dipped composite materials reinforced with glass fibre and Silicon Oxide under three different impingement angles (30°, 60° and 90°), three different impact velocities (23, 34 and 53 m/s), two different angular Aluminum abrasive particle sizes (approximately 200 and 400 μm) and the fibre orientation of 45° (45/-45) were investigated. In the test results, erosion rates were obtained as functions of impingement angles, impact velocities, particle sizes and fibre orientation. Moreover, materials with addition of Silicon Oxide filler material exhibited lower wear as compared to neat materials with no added filler material. In addition, SEM views showing worn out surfaces of the test specimens were scrutinized.
Abstract: During 2011 and 2012 seasons, Zaghloul date palms received four sprays of silicon (Si) at 0.05 to 0.1% and selenium (Se) at 0.01 to 0.02%. Growth, nutritional status, yield as well as physical and chemical characteristics of the fruits in response to application of silicon and selenium were investigated. Single and combined applications of silicon at 0.05 to 0.1% and selenium at 0.01 to 0.02% was very effective in enhancing the leaf area, total chlorophylls, percentages of N, P and K in the leaves, yield, bunch weight as well as physical and chemical characteristics of the fruits in relative to the check treatment. Silicon was superior to selenium in this respect. Combined application was favorable than using each alone in this connection. Treating Zaghloul date palms four times with a mixture of silicon at 0.05% + selenium at 0.01% resulted in an economical yield and producing better fruit quality.
Abstract: This paper presents the experimental results on
ageing deterioration of silicone rubber outdoor polymer insulator
under salt water dip wheel test based on IEC 62217. In order to comparison effect of chemical contents, silicone rubber outdoor
polymer insulators having same configuration and leakage distant
from two manufactures were tested together continuously 30,000 test cycles. Many discharge activities were observed in during the test.
After 30,000 test cycles, in spite of same configuration, differences in
degree of surface aging were observed. Physical analysis such as
decreasing in hydrophobicity and increasing in hardness
measurement were measured on two-type tested specimen surface in order to confirm degree of surface ageing. Furthermore, chemical
analysis by ATR-FTIR to diagnose the chemical change of tested
specimen surface was conducted to confirm the physical analysis results.