Power swing is a power system transient phenomenon that arises due to several reasons including line switching, line outage, sudden increment or decrement in load, faults, etc. Unnecessary tripping during power swing and unnecessary blocking for faults occur during power swing result in distance relay maloperation. Several cascaded outages and major worldwide blackouts have occurred due to maloperation of distance relays. This paper proposes a technique for supervising distance relays during power swing. The proposed
online technique discriminates real faults and power swing accurately. It relies on constructing a locus diagram for the current and voltage differences (ΔI-ΔV) between the two ends of the protected line. The locus is estimated at every power frequency cycle to continuously monitor the state of the line by utilizing the synchrophasor measurements at the sending and receiving ends of the line. The proposed technique is tested for two-area, four-machine power system under faults at different locations of zone-1 and zone-2 regions of distance relays, fault resistances, fault inception angles and slip frequencies using MATLAB software. The simulation results proved the superior improvement of distance relay performance for handling power swing blocking and unblocking actions.

This paper presents an accurate fault location scheme for transmission systems consisting of an overhead line in combination with an underground power cable. The algorithm requires phasor measurements data from one end of the transmission line and the synchronized measurements at the most far end of the power cable. Fault location is derived using distributed line model, modal transformation theory and Discrete
Fourier Transform. The technique can be used on-line or off-line using the data stored in the digital transient recording apparatus. The proposed scheme has the ability to locate the fault whether it is in the overhead line or in the underground power cable. Extensive simulation studies carried out using MATLAB show that the proposed scheme provides a high accuracy in fault location under various system and fault conditions.

BACKGROUND: Bladder cancer recurrence following cystectomy remains a significant cause of bladder cancer-specific mortality. Residual cancer cells (RCCs) contribute to cancer recurrence due either to tumor spillage or undetectable pre-existing micrometastatic tumor clones. We sought to detect and quantify RCCs in pelvic washing using ultra-deep targeted sequencing (UTS) and compare the levels of RCCs with clinical variables and cancer recurrence.

METHODS: 17 patients underwent robotic-assisted radical cystectomy (RARC) with primary tumor specimen available. All tumors had negative surgical margins. Pelvic washes and blood were collected intra-operatively: before RARC, after RARC, after pelvic lymph node dissection (PLND), and in the suction fluid collected during the procedure. A two-step sequencing, including whole-exome sequencing (WES) followed by UTS (>50,000X), was used to quantify RCCs in each sample. Eight patients were excluded due to sample quality issues. The final analysis cohort included nine patients. RCC level was quantified for each sample as the relative cancer cell fraction (RCCF), and compared between different time points. The peak RCCF (pRCCF) of each patient was correlated with clinical and pathological variables.

RESULTS: RCCs were detected in approximately half of the pelvic washing specimens during or after RARC, but not before it. Higher levels of RCCs were associated with aggressive variant histology and cancer recurrence. Verifying the feasibility of using RCCs as a novel biomarker for recurrence requires larger cohorts.

CONCLUSIONS: Detection of RCCs in intra-operative peritoneal washes of bladder cancer patients undergoing radical cystectomy may represent a robust biomarker of tumor aggressiveness and metastatic potential.

This paper presents an adaptive fault location scheme for aged power cables using synchronized phasor measurements from both ends of the cable. The proposed fault location scheme is derived using the two terminal synchronized measurements incorporated with distributed line model, modal transformation theory and Discrete Fourier Transform. The proposed scheme has the ability to solve the problem of cable changing parameters, especially the change of the relative permittivity over its age and thus for the operating positive, negative, and zero-sequence capacitance changes. Extensive simulation studies are carried out using Alternative Transients Program ATP/EMTP. The simulation studies show that the proposed scheme provides a high accuracy in fault location calculations under various system and fault conditions. The results show that the proposed scheme responds very well to any fault insensitive to fault type, fault resistance, fault inception angle and system configuration. The proposed scheme solves the problem of aged cables with the change of the electric parameters. In addition to, it gives an accurate estimation of the fault resistance.

Reliable and accurate fault location algorithms for series-compensated transmission lines are challenges that arise in most of modern electrical power transmission grids. This paper proposes an accurate fault location algorithm for series-compensated transmission lines. Distributed parameters long transmission line model is used in this study to account for practical travelling waves’ effect during fault incidence. The proposed algorithm uses wavelet transform for only one cycle data window length of post-fault voltage signals to detect the faulted line, then Fast Fourier Transform for voltages and currents signals of three post-fault cycles (including the 1st cycle) to locate the fault. Only positive sequence network is used for the fault location calculations, hence, the algorithm does not depend on the zero sequence parameters (i.e., ground resistivity) which are depending on moisture, temperature, etc. Different types of grounded and ungrounded faults, fault locations, fault resistances, fault inception angles are applied to validate the robustness of the algorithm. The algorithm is tested using a real case study for a 380 kV, 400 km series compensated transmission line in Saudi Arabia using MATLAB and SIMULINK software. Extensive Simulation results show the effectiveness and robustness of the proposed algorithm under various fault conditions.

OBJECTIVES: To investigate the diagnostic accuracy of endomyometrial biopsy obtained via office hysteroscopy for the diagnosis of adenomyosis.

STUDY DESIGN: Cross-sectional study.

SETTING: Cairo University Teaching Hospital, Cairo, Egypt.

PATIENTS: A total of 404 premenopausal women with symptoms clinically suggestive of having adenomyosis.

INTERVENTIONS: All patients were subjected to 2-dimensional transvaginal sonography (TVS) in-office hysteroscopy examination with endomyometrial biopsy. Patients who subsequently underwent hysterectomy were included in the final analysis.

MAIN MEASUREMENTS AND RESULTS: Accuracy of diagnostic modalities was represented using the terms sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy. A total of 292 patients were eligible for final analysis. Of these, 162 (55.47%) were diagnosed with adenomyosis based on hysterectomy specimens. TVS had a high sensitivity (83.95%) and a moderate specificity (60%). In contrast, endomyometrial biopsy was more specific (78.46%) than sensitive (54.32%). Hysteroscopic appearance of the endometrial cavity had low sensitivity (40.74%) and specificity (44.62%). Adding endomyometrial biopsy to TVS improved specificity (89.23%).

CONCLUSION: Endomyometrial biopsy obtained via office hysteroscopy can diagnose adenomyosis with a high specificity and is recommended after TVS.

The acceleration of ultra high energy cosmic rays is conjectured to occur through various interactions with the electromagnetic fields in different astrophysical objects, like magnetic matter clumps, besides the well-known shock and stochastic Fermi mechanisms. It is apparent that the latter are not depending on the particle's charge, quantitatively. Based on this model, a considerable portion of the dynamics, that derives a charged particle parallel to a magnetic field and under the influence of a force, is assumed to be composed of an acceleration by a non- magnetic force and a gyromotion along direction, plus drifts in the direction of The model and its formalism are introduced. Various examples for drift motions and accelerating forces are suggested. The formalism is given in a non-relativistic version. Obviously, the translation into the relativistic version is standard. In a forthcoming work, a quantitative estimation of the energy gained by charged cosmic rays in various astrophysical objects will be evaluated.