Advanced Materials Research Vols. 1079-1080

Abstract: Oil immersed transformer is an important equipment ofpower system, whose fault is often caused by the aging of insulation. In actualoperation, accurate calculation of the temperature field, especially hot spottemperature of transformer winding, is very important for stabilizing the powergrid operation and extending the transformer life. In order to calculate thetransformer's hot spot temperature accurately, a new method which is based oncomparison of respective advantages of the FEM and FVM is used; we take a31.5MVA transformer as exemple, using the hybrid method of the FEM and the FVM,the three-dimensional temperature field of transformer is calculated. Bycomparing the figures of top oil temperature of transformer monitored by theoperating transformer and the figures calculated by mixed method, the marginerror of the hot spot temperature is only 1.9°C. While the IEEE guidelines formodel calculation results, the calculated results of FEM algorithm and FVMalgorithm results with the monitoring data of standard deviation were as highas 4.6 °C, 3.8 °C and 3.1 °C. The Calculation accuracy is much higher than theaccuracy of the result using IEEE regulatory model, FEM and FVM, proved thatthis mixed method can calculate the internal temperature field of oil immersedtransformer accurately.

Abstract: This 2-phase study was carried out in an adult medical ICU with modified Nightingale type layout at a medical center in central Taiwan. Among 17 wards, 8 were selected for sampling test. The averages of CO₂ level in both phases met the legal requirement. A significant difference of CO₂ concentration was found among different locations of the sampling wards. The top two occurred in the location of off the circulation (Ward E) and facing the entrance (Ward A), the lowest occurred in the middle of the circulation (Ward C and G). Significant associations were found between CO₂ concentration and number of visitors in 5 sampling wards, except Ward C and G.

Abstract: China has become the largest carbon emitter in the world since 2008 for its coal dominated energy structure, which has attracted both economic and political attention from international society. This paper proposes a responsibility sharing principle for carbon emissions considering carbon emission efficiency and energy structure, which tries to promote the regional cooperation for carbon reduction among different regions on the domestic level. The case studies on China’s six-region carbon flow network prove the effectiveness of proposed sharing principle.

Abstract: This work is focused on the 0.25 μm 60 V high-voltage pLDMOS deviceswhich will be integrated with an FOD structure in the bulk region, and its ESD protection ability is improved by using this architecture. It is found that as an FOD element adding, the FOD area ratio is increased, I_t2 value will be enhanced too. However, as the FOD area ratio is increased, the V_t1 value of thecorresponding sample is not changed so much about a range of 1 ~ 2V; at thesame time the R_on value will be declined, which were due to a uniformconduction phenomenon. From the experimental data,it is revealed that the I_t2value improved 15.4%, and R_on valuedecreased about 8.6%.

Abstract: Thehottest spot temperature (HST) of windings of oil-immersed transformer is animportant factor that affects load capacity and operation life of transformer,and is closely related to the transformer load, top oil and environmenttemperature. HST, when operating at high temperature and overload, may lead totransformer failure which will affect the normal operation of the power system.In order to calculate the transformer hot spot temperature accurately, we takea 33MVA-500KV transformer as an example, and establish a three dimensionalmodel, get its internal temperature distribution based on Fluent simulationsoftware. At last, we comparative and analysis the accuracy of FVM calculation andIEEE guidelines recommend model combined with online monitored values. Theresults show that the FVM method with higher accuracy relative to the IEEEguidelines model, proved that using the FVM can accurately calculate the HST ofoil-immersed transformer.

Abstract: Ecological studies have shown that the chronic effects of exposure to environmental noise cause annoyance. However, in the past, most studies have used questionnaires to evaluate the effects of noise pollution on psychosomatic responses. This study investigated cardiovascular activity changes in exposure to low-frequency noise at various noise intensities. The authors hypothesized that distinct noise intensities affect cardiovascular activity, which would be reflected in the spectral analysis parameters. The evaluation intensities of low frequency noises (from 20 to 200 Hz) were background noise (BN), 70-dBC, 80-dBC, and 90-dBC. The electrocardiographic (ECG) data was recorded for 5 minutes under various noise levels. The cardiovascular responses were evaluated using spectral analysis of the beat-to-beat (RR) intervals obtained from ECG signals. The results showed that the average blood pressure and mean RR interval variability did not substantially change relative to the noise levels. However, the low-frequency (LF) power and the ratio of LF power to high-frequency power (LF/HF) from ECG under the BN condition were significantly lower than the 80-dBC, and 90-dBC noise levels. In addition, the normalized LF of the background noise condition was significantly lower than the low-frequency of the noise levels at various intensities. In conclusion, the frequency-domain-based measures appear to be a powerful tool for exposure to low-frequency noise, even in short-term heart rate variability time series.

Abstract: To study the corrosion of old 220kV transmission lines especially conductor in Shanghai, methods as visual inspection andmetallographic analysis are used to conduct an experimental research on the atmospheric corrosion of old conductors. The appearances and metallographic structures of conductors in service are examined and their mechanical property indicators are analyzed.Based on the corrosion mechanism of aluminum and galvanized steel wires, the research on the corrosion of ACSR which has run for years concludes that the outer aluminum wires of the 220kV old conductors that have operated for years are more corroded than the inner wires and the resistivity exceeds the standards although there is no significant drop in the mechanical indicators. The results in this research can provide technical support and guidance for the life evaluation of old transmission lines in the country.

Abstract: Withthe acceleration of the new rural construction, meanwhile, the problem ofbuilding energy consumption is increasingly protruding. As the most importantpart of rural residential construction of retaining structures and its thermalwill play a decisive role on heat preservation andheat insulation of the residence. Therefore, it is imperative to study ruralresidential technology retaining structure in southern Henan province, which toimprove energy consumption structure in rural areas and to improve the ruralresidential energy-saving.

Abstract: For the vast rural areas in our province with complex terrain, the centralized sewerage facilities are backward, but the integrated equipments in wastewater treatment can be effectively applied to these places. As a decentralized wastewater treatment technologies, the use of the integrated equipment in wastewater treatment is more and more wide. The technology of itself is also becoming more complete. This paper concludes and summarizes the technological developments and applications of the integrated equipment in wastewater treatment from abrod to home,from single to complicate, analyses the shortages of the integrated equipments in wastewater treatment;and introduces the development of the integrated equipments in wastewater treatment.

Abstract: The water pollution and water scarcity have restricted the development of economy seriously in Xi'an. And the wastewater quantity is an important basic data in solving this problem. This paper build GM(1,1) model based on grey system theory to predict the discharge volume of urban domestic sewage and industrial wastewater from 2013 to 2020. The predictions suggest that the discharge amount of industrial wastewater will reduce by 6.7005 million tons per year. While the amount of domestic sewage increases year by year at the speed of 11.0989 million tons. The percentage of domestic sewage in total sewage emissions will get bigger in Xi'an. Additionally, some suggestion about improving the efficiency using of water and reducing sewerage discharged are given.