Advanced Materials Research Vol. 983

Abstract: This paper presents a guideline of determining impedance of transformer when conducting system study for renewable energy interconnection. The method can be used when there is lack of information on the transformer’s technical details. Simulation examples are presented to demonstrate the effect of impedance on the losses and short circuit current. The guidelines introduce in this paper will increase reliability and accuracy of the system study conducted by engineer and researchers in assessing the possible impact renewable energy integration.

Abstract: The method presented below makes it possible to obtain an approximate solution to the problem of translational-rotational motion of proofmass in Hill's gravity field, as explicit functions of time.

Abstract: The benefit of improving the efficiency of photovoltaic (PV) solar system has come into view because of increasing the demand for electricity, especially in the urban areas. However, these PV solar systems are vulnerable to the mismatch operating conditions. Under such conditions, the performance of solar cells has decreased rapidly since the nonuniform insolation hitting the cells and with different values. Then this leads to cause rapidly decreasing in the output power value and maximum power point, beside to hot spot points that may be occurring in the solar cell which finally leads to damage these cells. This paper proposes an optimal connection of substrings with different value of shadow conditions, based on a thorough configuration that can significantly reduce that nonuniform condition loss. The refinement over existing photovoltaic (PV) solar array interconnections is proven by extensive simulation results by using MATLAB SIMULINK.

Abstract: Steel-wood combination guardrail is a kind of environment-friendly and harmonious highway ancillary structure. It can provide comfortable and superior experience for highway users. At present, there is no steel-wood combination guardrail qualified for 160kj protection level of highway barriers in China. The Development of New Steel Backing Wood Landscape Guardrail takes reliability, economical efficiency, convenience of construction into account. The researchers optimize structure by computer simulation. This guardrail eventually passed the full-scale impact test with real vehicle. The test proves that it can become a model applied on the actual scenic highway.

Abstract: An overview of the development of lead-based alloys in lead-acid batteries is presented. Advantages and historical achievements of toxic cadmium, arsenic alloys are affirmed. Compared to cadmium-free and arsenic-free batteries, the shortcomings and performance gapes of cadmium-containing, arsenic-containing batteries are noted. Focusing the prospect of rare earth alloy, and overall promotion of cadmium-free and arsenic-free alloys in China.

Abstract: Complexes of cell-THPC-thiourea-ADP with Mg²⁺ have been prepared. The thermal stability and smoke suspension of the samples are determined by TG, DTA and cone calorimetry. Experimental data show that for the complexes of cell-THPC-thiourea-ADP with Mg²⁺, thermal decomposition temperatures are higher than those of cell-THPC-thiourea-ADP, which shows these metal ions can increase the thermal stability of cell-THPC-thiourea-ADP. The cone calorimetry data indicate that the metal ions greatly decrease the smoke, CO and CO₂ generation of cell-THPC-thiourea-ADP, which can be used as smoke suppressants. However, there are no obvious effects for these metal ions on heat release of samples.

Abstract: Based on phonon theory the interaction of high frequency sound (ultrasound and hypersonic) with crystal lattices in solids was estimated. The coefficients of absorption in dielectrics and metals, with respect to temperature and sound frequency, were calculated. Analysis of the calculated dependences allows obtaining of nanomaterials with the set sound conductivity and sound absorption in high frequency range.

Abstract: Internal flow field and noise of outlet blockage fault and trouble-free for control valve are studied by CFD. The study shows that the pressure of front-end and back-end for blockage is respectively increased, but the upper pressure is reduced. Two strong vortexes are formed at front-end and back-end of blockage, which reduce noise of pipe after valve.

Abstract: Nowadays the use of biodegradable plastic in the food industry has increased dramatically. Because of its outstanding characteristics, i.e. environmental friendliness and non-toxicity, researchers are interested in studying how to improve the properties of plastic, especially polylactic acid or PLA, which is very fragile and intolerant to high impact force. Attempts have been made to improve the weak points of PLA by mixing PLA with epoxidized natural rubber. The natural rubber goes through an epoxidation process, resulting in epoxidized natural rubber (ENR) as the finished product. ENR contains epoxy groups which can efficiently react with PLA. Ratios of PLA and ENR employed in this study were 50:50, 60:40, 70:30, 80:20 and 90:10. In addition to finding a suitable ratio between PLA and ENR, the mixtures were subjected to migration tests according to the guidelines specified in European Commission Regulation (EU) No 10/2011 in order to prove whether the mixed materials are safe and suitable for consumer use. Migration testing was conducted by soaking samples in four different food simulants – 10% (v/v) ethanol in aqueous solution, 3% (w/v) acetic acid in aqueous solution, 20% (v/v) ethanol in aqueous solution and vegetable oil – for 24 h at 40 °C. The results showed that the PLA/ENR blends at every ratio had an overall migration amount of less than 10 mg/dm² in three of the sample simulants, while the overall migration from materials soaked in vegetable oil exceeded this standard. Migration tests of one of the sample blends conducted at 100 °C for 2 h showed similar results. In conclusion, polymer blends of PLA and ENR are appropriate for food packaging applications, but are not appropriate for foods containing vegetable oil.

Abstract: The actual supercharged boiler is reasonably simplified and the geometric model of the furnace and the mathematical model of steady-state three-dimensional turbulent reaction are built in this paper. Numerical simulation of the thermal NOx emission under three different loads in the furnace of a supercharged boiler is conducted with FLUENT software. The thermal NOx emission increases in the furnace when the load increases and the largest mole fraction of the thermal NOx mainly exists at the back edge of high temperature.