Abstract: The article presents part of research on the development of nickel plated welding wire production technology, whose application will enable the elimination of the flaws of currently manufactured welding wires. The nickel plated welding wire will be distinguished by high quality, because the Ni layer which is deposited electrochemically onto it from acid baths is characterized by very good adhesion to the steel wire surface, while the ductile nickel well deforms plastically in the drawing process and the adhesion of the Ni layer increases in the drawing process due to the occurring process of diffusion between the Ni and the steel. The Ni layer obtained in the proposed technology, despite a smaller thickness than when the wire is coated with copper, is continuous and tight, thus ensuring high corrosion resistance, as well as unsusceptible to scaling, which should provide a product that meets requirements imposed by the market. The product will also reduce, to some extent, the amount of copper brought in to steel through recycling, while the wire coating nickel introduced to the weld in the welding process is expected, to a degree, to favorably influence its mechanical properties. The paper describes the tests of the process of nickel plating of f1.96 mm-diameter wires using various nickel plating baths with different process parameters.
Abstract: One-dimensional (1D) nanostructures like nanowires, nanotubes, and nanorods find variety of practical application owing to their unique physico-chemical properties. In this work, TiO2 nanowires were synthesized by direct oxidation of titanium particles in a unique microwave plasma jet reactor. The prepared TiO2 nanowires manifested the flexible features, and were characterized by using X-ray diffraction, Brunauer-Emmett-Teller (BET) surface area analyzer, UV-Visible and FTIR spectrophotometers, Scanning electron microscope, and Transmission electron microscope. Further, the photodegradation efficiency of these nanowires were tested against toxic organic dye like methylene blue (MB) and the results were compared with the commercial TiO2. It was found that TiO2 nanowires exhibited superior photocatalytic performance (89%) as compared to commercial TiO2 (75%) after 60 min of reaction. This is attributed to the lower recombination rate and increased interfacial charge transfer in TiO2 nanowire. Pseudo-first order kinetic modelling performed with the experimental results revealed that the rate constant of photodegradation in case of TiO2 nanowire was 1.3 times higher than that of commercial TiO2. Superoxide radical (O2˙−) was found to be the major contributor in the photodegradation mechanism. Based on the trapping experiments, a plausible mechanism of the photocatalytic reaction is discussed.
Abstract: The surface and bulk magnetization behavior of template released isolated ferromagnetic Ni60Fe40 nanowires of relatively thick diameters (~200 nm), deposited from a dilute suspension onto pre-patterned insulating chips have been investigated experimentally, using a highly sensitive Magneto-Optical Ker Effect (MOKE) magnetometry and Magneto-Resistance (MR) measurements, respectively. The MR data were consistent with the theoretical predictions of the anisotropic magneto-resistance (AMR) effect. The MR measurements, in all the angles of investigations, showed large features and a series of nonmonotonic "continuous small features" in the resistance profiles. The extracted switching fields from these features and from MOKE loops were compared with each other and with the switching fields reported in the literature that adopted the same analytical techniques on the similar compositions and dimensions of nanowires. A large difference between MOKE and MR measurments was noticed. The disparate between MOKE and MR results is attributed to the variance in the micro-magnetic structure of the surface and the bulk of such ferromagnetic nanowires. This result was ascertained using micro-magnetic simulations on an individual: cylindrical and rectangular cross sections NiFe nanowires, with the same diameter/thickness of the experimental wires, using the Object Oriented Micro-magnetic Framework (OOMMF) package where the simulated loops showed different switching events, indicating that such wires have different magnetic states in the reversal process and the micro-magnetic spin structures during switching behavior was complicated. These results further supported the difference between surface and bulk magnetization behavior in these nanowires. This work suggests that a combination of MOKE and MR measurements is required to fully understand the magnetization behavior of such relatively thick isolated cylindrical ferromagnetic nanowires.
Abstract: Mobile ad hoc network (MANET) is a self-configuring network of mobile node connected without wires. A Fuzzy Logic Based Collaborative watchdog approach is used to reduce the detection time of misbehaved nodes and increase the overall truthfulness. This methodology will increase the secure efficient routing by detecting the Black Holes attacks. The simulation results proved that this method improved the energy, reduced the delay and also improved the overall performance of the detecting black hole attacks in MANET.
Abstract: The Hall Coefficient (HC) and the Magnetoresistance (MR) have been studied in two-dimensional systems. The HC and the MR in Rectangular Quantum Wire (RQW) subjected to a crossed DC electric field and magnetic field in the presence of a Strong Electromagnetic Wave (EMW) characterized by electric field are studied in this work. Using the quantum kinetic equation for electrons interacting with optical phonons, we obtain the analytic expressions for the HC and the MR with a dependence on magnetic field, EMW frequency, temperatures of systems and the length characteristic parameters of RQW. These expressions are different from those obtained for bulk semiconductors and cylindrical quantum wires. The analytical results are applied to GaAs/GaAs/Al. For this material, MR depends on the ratio of the EMW frequency to the cyclotron frequency. Indeed, MR reaches a minimum at the ratio 5/4, and when this ratio increases, it tends towards a saturation value. The HC can take negative or positive values. Each curve has one maximum and one minimum. When magnetic field increases, the HC is negative, achieves a minimum value and then increases suddenly to a maximum with a positive value. This phenomenon differs from the one observed in cylindrical quantum wire, which does not have maximum and minimum values.
Abstract: The strain intensity and redundant strains, dependent
in multistage TRIP wire drawing processes from values used single
partial reductions, should influence on the intensity of transformation
the retained austenite into martensite and thereby on mechanical
properties of drawn wires. The numerical analysis of drawing
processes with use of Drawing 2D programme, for steel wires made
from TRIP steel with 0,29% has been shown in the work. The change
of strain intensity εc and the values of redundant strain εxy, has been
determined for particular draws in dependence of used single partial
reductions.
Abstract: Quantum-dot Cellular Automata (QCA) is one of the most substitute emerging nanotechnologies for electronic circuits, because of lower power consumption, higher speed and smaller size in comparison with CMOS technology. The basic devices, a Quantum-dot cell can be used to implement logic gates and wires. As it is the fundamental building block on nanotechnology circuits. By applying XOR gate the hardware requirements for a QCA circuit can be decrease and circuits can be simpler in terms of level, delay and cell count. This article present a modest approach for implementing novel optimized XOR gate, which can be applied to design many variants of complex QCA circuits. Proposed XOR gate is simple in structure and powerful in terms of implementing any digital circuits. In order to verify the functionality of the proposed design some complex implementation of parity generator and parity checker circuits are proposed and simulating by QCA Designer tool and compare with some most recent design. Simulation results and physical relations confirm its usefulness in implementing every digital circuit.
Abstract: The fracture performance of steel wires for civil engineering applications remains a major concern in civil engineering construction and maintenance of wire reinforced structures. The need to employ approaches that simulate micromechanical material processes which characterizes fracture in civil structures has been emphasized recently in the literature. However, choosing from the numerous micromechanics-based fracture models, and identifying their applicability and reliability remains an issue that still needs to be addressed in a greater depth. Laboratory tensile testing and finite element tensile testing simulations with the shear, ductile and Gurson-Tvergaard-Needleman’s micromechanics-based models conducted in this work reveal that the shear fracture model is an appropriate fracture model to predict the fracture performance of steel wires used for civil engineering applications. The need to consider the capability of the micromechanics-based fracture model to predict the “cup and cone” fracture exhibited by the wire in choosing the appropriate fracture model is demonstrated.
Abstract: In the article, the wire winding process for the reinforcement of a pressure vessel frame has been studied. Firstly, the importance of the wire winding method has been explained and literature was reviewed. The main step in the design process is the methodology axial force control. The frame consists of two columns and two semi-cylinders with circumstantial wires. A computational algorithm has been presented based on the governing equations and relations on stress-strain behavior of the whole system of the frame. Then a case study was studied to calculate the frame dimensions and wire winding procedure.
Abstract: Structured catalysts formed from the growth of
zeolites on substrates is an area of increasing interest due to the
increased efficiency of the catalytic process, and the ability to
provide superior heat transfer and thermal conductivity for both
exothermic and endothermic processes.
However, the generation of structured catalysts represents a
significant challenge when balancing the relationship variables
between materials properties and catalytic performance, with the
Na2O, H2O and Al2O3 gel composition paying a significant role in
this dynamic, thereby affecting the both the type and range of
application.
The structured catalyst films generated as part of this
investigation have been characterised using a range of techniques,
including X-ray diffraction (XRD), Electron microscopy (SEM),
Energy Dispersive X-ray analysis (EDX) and Thermogravimetric
Analysis (TGA), with the transition from oxide-on-alloy wires to
hydrothermally synthesised uniformly zeolite coated surfaces being
demonstrated using both SEM and XRD. The robustness of the
coatings has been ascertained by subjecting these to thermal cycling
(ambient to 550oC), with the results indicating that the synthesis time
and gel compositions have a crucial effect on the quality of zeolite
growth on the FeCrAlloy wires.
Finally, the activity of the structured catalyst was verified by a
series of comparison experiments with standard zeolite Y catalysts in
powdered pelleted forms.
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: 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: This research proposed a new design of helmet-shaped
array transcranial magnetic stimulation coil system. It was constructed
using several sagittal directional wires and several coronal directional
wires. By varying the current direction and strength on each wire, this
array coil system could be constructed into the circular coil and
figure-eight coil of different size. Also, this proposed coil system can
flexibly not only change the stimulation location, range, type and
strength, but also change the shape and the channel number of coil
dynamically.
Abstract: Each new semiconductor technology node
brings smaller transistors and wires. Although this makes
transistors faster, wires get slower. In nano-scale regime, the
standard copper (Cu) interconnect will become a major hurdle
for FPGA interconnect due to their high resistivity and
electromigration. This paper presents the comprehensive
evaluation of mixed CNT bundle interconnects and
investigates their prospects as energy efficient and high speed
interconnect for future FPGA routing architecture. All
HSPICE simulations are carried out at operating frequency of
1GHz and it is found that mixed CNT bundle implemented in
FPGAs as interconnect can potentially provide a substantial
delay and energy reduction over traditional interconnects at
32nm process technology.
Abstract: Due to insufficient frequency band and tremendous growth of the mobile users, complex computation is needed for the use of resources. Long distance communication began with the introduction of telegraphs and simple coded pulses, which were used to transmit short messages. Since then numerous advances have rendered reliable transfer of information both easier and quicker. Wireless network refers to any type of computer network that is wireless, and is commonly associated with a telecommunications network whose interconnections between nodes is implemented without the use of wires. Wireless network can be broadly categorized in infrastructure network and infrastructure less network. Infrastructure network is one in which we have a base station to serve the mobile users and in the infrastructure less network is one in which no infrastructure is available to serve the mobile users this kind of networks are also known as mobile Adhoc networks. In this paper we have simulated the result for different scenarios with protocols like AODV and DSR; we simulated the result for throughput, delay and receiving traffic in the given scenario.
Abstract: Network on Chip (NoC) has emerged as a promising
on chip communication infrastructure. Three Dimensional Integrate
Circuit (3D IC) provides small interconnection length between layers
and the interconnect scalability in the third dimension, which can
further improve the performance of NoC. Therefore, in this paper,
a hierarchical cluster-based interconnect architecture is merged with
the 3D IC. This interconnect architecture significantly reduces the
number of long wires. Since this architecture only has approximately
a quarter of routers in 3D mesh-based architecture, the average
number of hops is smaller, which leads to lower latency and higher
throughput. Moreover, smaller number of routers decreases the area
overhead. Meanwhile, some dual links are inserted into the bottlenecks
of communication to improve the performance of NoC.
Simulation results demonstrate our theoretical analysis and show the
advantages of our proposed architecture in latency, throughput and
area, when compared with 3D mesh-based architecture.
Abstract: We report the size dependence of 1D superconductivity in ultrathin (10-130 nm) nanowires produced by coating suspended carbon nanotubes with a superconducting NbN thin film. The resistance-temperature characteristic curves for samples with ≧25 nm wire width show the superconducting transition. On the other hand, for the samples with 10-nm width, the superconducting transition is not exhibited owing to the quantum size effect. The differential resistance vs. current density characteristic curves show some peak, indicating that Josephson junctions are formed in nanowires. The presence of the Josephson junctions is well explained by the measurement of the magnetic field dependence of the critical current. These understanding allow for the further expansion of the potential application of NbN, which is utilized for single photon detectors and so on.
Abstract: This study describes analysis of tower grounding
resistance effected the back flashover voltage across insulator string
in a transmission system. This paper studies the 500 kV transmission
lines from Mae Moh, Lampang to Nong Chok, Bangkok, Thailand,
which is double circuit in the same steel tower with two overhead
ground wires. The factor of this study includes magnitude of
lightning stroke, and front time of lightning stroke. Steel tower uses
multistory tower model. The assumption of studies based on the
return stroke current ranged 1-200 kA, front time of lightning stroke
between 1 μs to 3 μs. The simulations study the effect of varying
tower grounding resistance that affect the lightning current.
Simulation results are analyzed lightning over voltage that causes
back flashover at insulator strings. This study helps to know causes
of problems of back flashover the transmission line system, and also
be as a guideline solving the problem for 500 kV transmission line
systems, as well.
Abstract: ZnO heteronanostructured nanowires arrays have
been fabricated by low temperature solution method. Various
heterostructures were synthesized including CdS/ZnO,
CdSe/CdS/ZnO nanowires and Co3O4/ZnO, ZnO/SiC
nanowires. These multifunctional heterostructure nanowires
showed important applications in photocatalysts, sensors,
wettability control and solar energy conversion.
Abstract: In this study, we introduced a communication system
where human body was used as medium through which data were
transferred. Multiple biosignal sensing units were attached to a subject
and wireless personal area network was formed. Data of the sensing
units were shared among them. We used wideband pulse
communication that was simple, low-power consuming and high data
rated. Each unit functioned as independent communication device or
node. A method of channel search and communication among the
modes was developed. A protocol of carrier sense multiple
access/collision detect was implemented in order to avoid data
collision or interferences. Biosignal sensing units should be located at
different locations due to the nature of biosignal origin. Our research
provided a flexibility of collecting data without using electrical wires.
More non-constrained measurement was accomplished which was
more suitable for u-Health monitoring.