Tests on the First 500 kV Compact Transmission Line in China

The paper deals with the tests on the first 500 kV compact transmission line. The transmission line stretches from Fangshan Substation to Changping Substation nearby Beijing with a length of 83 km. In order to investigate the characteristics of the transmission line, many tests were performed on the line before and after its operation. The results indicate that all electrical parameters are perfectly identical to the design.

Incidence and Factors Associated with the Switch to the Second Line Antiretroviral Treatment at the Ambulatory Treatment Center (CTA) in Dakar

Introduction: Over the past years, efforts have been made to expand access to antiretroviral combinations (cART) in low-income countries. However, major concerns are noted with drug resistance emergence, as treatment failure result and need to introduce a second line treatment, more expensive and difficult to implement. The objective was to study the incidence of switch to second line, reasons for switch and risk factors using a cohort of people living with HIV in an Ambulatory Treatment Center in Dakar. Methodology: This was a cohort study of people living with HIV under cART from January 2004 to December 2013. Naive patients monitored for at least six months, regardless of their profile and regimen with baseline CD4 counts Results: The median age of the 827 patients included was 44 [IQR = 18 - 78]. The switch to second-line treatment was observed in 72 patients (8.7%) after an average of 38.5 months of follow-up. The overall incidence rate of switch to second line of antiretroviral treatment was 1.59 per 100 persons-years. Most of changes in first-line treatment were motivated by virological failures (n = 60, 83.3%) under treatment with AZT/3TC/NVP (n = 25, 34.7%) or AZT/3TC/EFV21 (29.2%). 9.7% of switch occurred after immunological failure, 1.4% after clinical failure, 4.2% after severe toxicity and 1.4% was not documented. Predictive factors identifying failures at the end of the multivariate analysis were age Conclusions: In total, CTA identified a low incidence rate of treatment failure of the first line of treatment. Associated risk factors were age < 44 years, CD4 counts below 100 cells/mm3 and high viral load at treatment initiation.

Day-ahead Voltage-stability-constrained Network Topology Optimization with Uncertainties

A day-ahead voltage-stability-constrained network topology optimization(DVNTO)problem is proposed to find the day-ahead topology schemes with the minimum number of operations(including line switching and bus-bar splitting)while ensuring the sufficient hourly voltage stability margin and the engineering operation requirement of power systems.The AC continuation power flow and the uncertainty from both renewable energy sources and loads are incorporated into the formulation.The proposed DVNTO problem is a stochastic,largescale,nonlinear integer programming problem.To solve it tractably,a tailored three-stage solution methodology,including a scenario generation and reduction stage,a dynamic period partition stage,and a topology identification stage,is presented.First,to address the challenges posed by uncertainties,a novel problem-specified scenario reduction process is proposed to obtain the representative scenarios.Then,to obtain the minimum number of necessary operations to alter the network topologies for the next 24-hour horizon,a dynamic period partition strategy is presented to partition the hours into several periods according to the hourly voltage information based on the voltage stability problem.Finally,a topology identification stage is performed to identify the final network topology scheme.The effectiveness and robustness of the proposed three-stage solution methodology under different loading conditions and the effectiveness of the proposed partition strategy are evaluated on the IEEE 118-bus and 3120-bus power systems.

Optical True Time Delay for Phased Array Antennas Composed of 2×2 Optical MEMS Switches and Fiber Delay Lines

We proposed an optical true time delay (TTD) for phased array antennas (PAAs) composed of 2×2 optical MEMS switches, single-mode fiber delay lines, and a fixed wavelength laser diode. A 3-bit TTD for 10 GHz PAAs was implemented with a time delay error less than ± 0.2 ps.