Impacts of Light Rail Transit Tram on the Voltage and Unbalance of the Distribution System

This paper presents the three-phase voltage and unbalance analysis for the distribution system with the loading of a light rail transit (LRT) tram. To investigate the dynamic responses of the system voltage and current, this paper adopts the Alternative Transients Program (ATP) software to model and simulate a multigrounded four-wire distribution system with an LRT loading. Two different definitions about unbalance are used to evaluate the problem. In this paper, the traction supply substation (TSS) with a single-phase transformer configuration is designed first for providing the electric power to the trams of LRT. However, it may result in the significant neutral line current and unbalance phenomenon to deteriorate the power quality of the distribution system. A Le-Blanc connection transformer in the TSS is therefore proposed to solve the problems

Global Magnitude of Reported and Unreported Mesothelioma

BACKGROUND: Little is known about the global magnitude of mesothelioma. In particular, many developing countries, including some with extensive historical use of asbestos, do not report mesothelioma. OBJECTIVES: We estimated the global magnitude of mesothelioma accounting for reported and unreported cases. METHODS: For all countries with available data on mesothelioma frequency and asbestos use (n = 56), we calculated the 15- year cumulative number of mesotheliomas during 1994-2008 from data available for fewer years and assessed its relationship with levels of cumulative asbestos use during 1920-1970. We used this relationship to predict the number of unreported mesotheliomas in countries for which no information on mesothelioma is available but which have recorded asbestos use (n = 33). RESULTS: Within the group of 56 countries with data on mesothelioma occurrence and asbestos use, the 15-year cumulative number of mesothelioma was approximately 174,300. There was a statistically significant positive linear relation between the log-transformed national cumulative mesothelioma numbers and the log-transformed cumulative asbestos use (adjusted R -2 = 0.83, p < 0.0001). Extrapolated to the group of 33 countries without reported mesothelioma, a total of approximately 38,900 (95% confidence interval, 36,700-41,100 ) mesothelioma cases were estimated to have occurred in the 15-year period (1994-2008). CONCLUSIONS: We estimate conservatively that, globally, one mesothelioma case has been overlooked for every four to five reported cases. Because our estimation is based on asbestos use until 1970, the many countries that increased asbestos use since then should anticipate a higher disease burden in the immediate decades ahead

The incidence and risk of developing a second primary esophageal cancer in patients with oral and pharyngeal carcinoma: a population-based study in Taiwan over a 25 year period

<p>Abstract</p> <p>Background</p> <p>The incidence of oral and pharyngeal (including oral cavity, oropharynx and hypopharynx) carcinoma increases rapidly in Asia and South Pacific because of betel quid chewing. Thus far, large-scale epidemiological studies are not available yet to stratify these patients by their risks of developing a second primary cancer in the digestive tract including esophagus, stomach, colon, and rectum.</p> <p>Methods</p> <p>A population-based study was conducted using the database from the Taiwan National Cancer Registry for the period 1979-2003. We quantified standardized incidence ratios (SIRs) and cumulative incidence of second primary cancers among 33,787 patients with initial diagnoses of oral and pharyngeal carcinoma.</p> <p>Results</p> <p>Among these four digestive tract organs, the esophagus was the only site of second cancer with excess risk in patients with oral and pharyngeal carcinoma. The incidence and risk of developing a second primary esophageal cancer differed by the site of the primary index tumor, most frequently seen in hypopharyngeal cancer (71/4,218 = 1.68%, SIR = 22.76, 95% CI 17.77-28.70), followed by oropharyngeal cancer (30/3,403 = 0.88%, SIR = 14.29, 95% CI 9.64-20.39) and the least in oral cavity cancer (99/26,166 = 0.38%, SIR = 5.57, 95% CI 4.53-6.78). In addition, the risk was extraordinarily high for patients with a follow-up interval ≤ 1 year and those with first primary cancer diagnosed at age ≤50. These patients may justify more close surveillance.</p> <p>Conclusion</p> <p>The present study represents the first population-based study in Asia attempting to stratify the patients of oral and pharyngeal carcinoma by their risk of developing a second esophageal cancer. It helps identify patients at high risk and tailor the application of intense follow-up surveillance to the estimated risk in each individual case.</p

Characterisation of protein-nanoparticleconjugates

Depending on the nature of the nanoparticles, reactive oxygen species may be generated, thus disturbing the oxidative balance in the lung environment. The toxicity of the particle may be mitigated by components of the epithelial lining fluid, such as antioxidants. The presence of protein in the lining fluid could also resolve the biological effects of particle exposure. However, the mechanisms of protein-particle interaction remain unclear. Hydrophobic carbon-based nanoparticles were used to investigate the interactions between bovine serum albumin (BSA) and particles, including carbon black, which has an average diameter of 23 nm (CB23) or 65 nm (CB65); single-walled nanotubes (SWNTs), which have an average diameter of 1−2 nm (500 nm in length); and double-walled nanotubes (DWNTs), which have an average diameter of 5 nm (5−15 μm in length). The zeta potentials of the particles alone and of the protein-particle conjugates were determined (Figure 1). The zeta potentials of CB23, CB65, SWNTs and DWNTs dispersed in −0.4 mV d-H2O were 2.7, −3.9, −8.7 and 8.2 mV, respectively, and these values were significantly decreased to −24.3, −23.6, −19.3 and −20.4 mV, respectively, after the addition of −15.4 mV of BS