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A particular UHF “miniaturized” antenna is presented in this paper. It is a kind of planar inverted F antenna (PIFA) which operates in a metal environment. The return loss of the antenna has been optimized over the ISM european frequency band (868 MHz). To reduce the size of the structure, the resonator has been folded under “itself” and a capacitive load is added in order to decrease the resonance...
The use of transmission-line networks as periodic structures emulating many interesting metamaterial-related phenomena, such as negative refraction ([1], [2]) and cloaking ([3], [4]), has gained increasing interest in the scientific community. Transmission-line networks offer a simple way to create non-resonant, broadband structures exhibiting exotic wave propagation characteristics. A big drawback...
Knowing the elements in design is the chief requirements for a designer. With the deep research on elements, it becomes complicated, which makes it difficult for the designers. We need to find a way to make it simple. First of all, I made a comprehensive analysis on the elements to find the features and bring in ‘five elements balance’ theory to sort out it but not simply delete. More important, the...
Tensile shearing tests are used to investigate the mechanical property of laser welded Ti-6Al-4V lap joints. The load per length of weld bead is introduced to evaluate the bearing ability of laser lap joints, and the failure load ranges from 394 to 502N/mm. The optima parameters for 0.8mm thick Ti-6Al-4V alloy is 1800∼2350W laser power and 1.5∼2.5m/min welding velocity.
Aimed at problems that wrinkling and crack lie in the forming for the cylinder-shaped part, the program DYNAFORM is used to simulate the drawing process of the cylinder-shaped part to optimize forming process. Based on physical simulation, the effects of property parameters and blank holding force on deformability are studied in sheet metal drawing. The simulation result indicates that increase of...
There are many reports about pre-deformation on microstructure and mechanical properties of the alloy, but none about the CoCr alloy. This research proposed solutions to the compression and expansion test of the stents, and established an accurate test method to assess the mechanical properties of products, analyzed the pre-deformation on it and summarized the stress-strain characteristics of the...
In a typical arc spray prototyping process, two metal wires was melt by electric arc at certain distance and sprayed to the mold surface with high speed compressed air from the jet. To prevent failures such as deformation and cracking, homogeneous temperature field distribution was required for every spray layer. This can be achieved by optimizing the processing parameters using numerical simulating...
The faster development of automobile industry, the grimmer situation of disuse automobile reclamation. The actuality of disuse automobile reclamation is analyzed. Reclamation and utilizing of metal material, plastic and rubber materials for automobile are researched in detail on the objective of environment protection and economizing resources. Finally a series of countermeasures about disuse mobile...
The hydrophobicity before and after humic acid's adsorption on Fe2O3 nanoparticles in various solution conditions was investigated with FTIR spectrum and thermogravimetric analysis methods. The results showed that, when the ionic strength was kept at 0, 0.005, 0.01 and 0.05mol/kg and pH value was changed from 7 to 12, the thermal weight loss of the complex, which formed after the adsorption of nano...
A simple design of an electromagnetic cloak is used to “hide” metallic cylinders placed near a horn antenna. The antenna's directivity with and without the cloak is studied with numerical simulations to verify the operation of the cloak.
It has drawn the attention of state and society that the current rural sanitation work is facing many problems. In order to effectively solve the difficulty of domestic garbage disposal, the country decided to bring the work of garbage disposal in rural areas into the one of urban-rural integration. This paper analyzed the present situation and the existing problems of domestic garbage disposal in...
Photovoltaic (PV) power is a promising choice as low-cost, environmentally friendly energy source. Thin-film solar cell is proposed as an alternative to reduce the cost due to its very thin silicon absorbers and utilization of cheap substrates. However because of the thin thickness of thin film solar cell, the light absorption is poor. In order to increase the absorption efficiency, surface plasmonic...
With the theory[1–4] enabled technology, we have been able to purify information from zones up to two atomic spacings regarding the evolution of the bond length, bond strength, energy density, and the energetic behavior of the localized core and valence electrons by filtering out the bulk and background information, which enabled us to identify the direction of charge flow in the catalytic reactions...
Nanoparticles of Cobalt-Manganese oxides were prepared by chemical co-precipitation method. The samples were heated at 400, 600 and 800ºC. The average particle size was determined from the X-ray line broadening. The diffractogram was compared with JCPDS data to identify the crystallographic phase and cubic structure of the particles. The FTIR studies have been used to confirm the metal oxide formation...
Significant research has been performed in developing wafer-level metal/adhesive hybrid bonding technology by investigating bonding temperature optimization of SU-8 materials. The SU-8 wafers experience bonding failure when bonding temperature exceeds 275°C. As a result of the significant decomposition of epoxy rings and phenyl in plane bending above 275°C, Fourier Transform IR (FTIR) spectra measurements...
The microwave furnace casting process is a time and temperature dependent nonlinear process. In this paper, we present our multi-physics modeling of a microwave oven process that is based on a coupled 3D EM- thermal analysis. Our efforts include the development of the necessary procedures and tools/probes to electrically and thermally characterize all utilized materials over a wide temperature range...
Because of its simple structure, high density and good scalability, resistive random access memory (RRAM) is expected to be a promising candidate to substitute traditional data storage devices, e.g., hard-disk drive (HDD). In a conventional three-dimensional (3D) bipolar RRAM design, an isolation layer is inserted between two adjacent memory layers. The fabrication of the isolation layer introduces...
Synthesis of n-butyl lactate catalyzed by carbon nanotube pured liquid oxide was studied. The influence of the amount of catalyst, catalytic reaction time and temperature on the conversion rate of lactic acid was discussed. The synthesis conditions of n-butyl lactate are as follows: the ratio alcohol to acid is 2∶1, the amount of catalyst is 0.5 g/0.1mol lactic acid, the reaction time is 2.0 h and...
We present a novel approach for 3D-prototyping of porous metal structures by direct non-contact liquid metal printing, based on the StarJet technology [1]. In contrast to our previous work, the presented droplet generator features an improved nozzle chip design and actuator housing that allows operation at temperatures up to Tmax = 500°C (formerly Tmax = 250°C). This enables the ejection of single...
This paper reports the results of the material optimization of phosphorus-doped polycrystalline silicon germanium (poly-SiGe) for use in thermoelectric energy harvesting. The problem of high specific contact resistance is tackled by optimizing the microfabrication process and choosing a new metal stack for interconnect. Other material properties relevant to the thermoelectric energy harvesting have...
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