Fecal contamination of water bodies causes a public health problem and economic loss. To control such contamination management actions need to be guided by sound science. From 2007-2009 a study was undertaken to determine the sources of fecal bacteria contamination to the marine waters adjoining the Town of Wrightsville Beach, North Carolina, USA. The research effort included sampling for fecal...

This paper proposes a novel islanding detection method (IDM) for grid-connected photovoltaic systems (GCPVSs) through disturbance injection in the maximum power point tracking (MPPT) algorithm. When an absolute deviation of output voltage exceeds threshold, applied shifts system operating from its (MPP) condition. leads to sharp active reduction and consequently, significant drop islanded mode ...

Gas drainage in deep coal seam is a critical issue ensuring the safety of mining and an important measure to obtain gas as kind clean available energy. In order get better understanding flow diffusion for seams, dual-zone model, including damage zone (DDZ) non-damaged (NDZ), are characterized by different permeability models anomalous analyze influence induced drilling boreholes on flow. The mo...

Organic modification of nano-SiO2 particles was performed with supercritical CO2 as solvent and a titanate coupling reagent NDZ-201 as the modification reagent. The surface of the nano-SiO2 particles was changed after modification by the titanate coupling reagent from hydrophilic to hydrophobic. IR and thermo-gravimetric analyses indicate that the interaction between the titanate coupling reage...

-An active islanding detection method based on Frequency-Locked Loop (FLL) for constant power controlled inverter in single-phase microgrid is proposed. This method generates a phase shift comparing the instantaneous frequency obtained  from FLL unit with the nominal frequency to modify the reference phase angle. An initial low frequency variable triangular disturbance is added to the phase sh...

-An active islanding detection method based on Frequency-Locked Loop (FLL) for constant power controlled inverter in single-phase microgrid is proposed. This method generates a phase shift comparing the instantaneous frequency obtained  from FLL unit with the nominal frequency to modify the reference phase angle. An initial low frequency variable triangular disturbance is added to the phase sh...

PP/FG composite materials were prepared by compressing moulding under high temperature through high-speed mixer, mixing mill and vulcanization machine taking PP as the matrix resin, FG thermal conductive filler, NDZ-201 coupling agent. Effects of proportion, content particle size on conductivity mechanical properties studied. Results showed that proportion has little effect materials, but it gr...

Detection of unintentional islanding is critical in microgrids order to guarantee personal safety and avoid equipment damage. Most detection techniques are based on monitoring detecting abnormalities magnitudes such as frequency, voltage, current power. However, normal operation, the utility grid has fluctuations voltage codes establish that local generators must remain connected if deviations ...

This paper presents an investigation of different islanding detection techniques which focus on operating parameters. These parameters are to decide whether the system will be islanded or not. The process is based on measuring the voltage, frequency and phase angle at the point of common coupling. The rate of change must be integrated to distinguish the changes in the system, the rate of change...