Prediction of Refrigerant Leakage for Discharge Valve System in A Rolling Piston Rotary Compressor

The flow coefficient of a discharge valve system with lift height was functionalized by experiments and Computational Fluid Dynamics(CFD) simulation to predict the mass flow rate through a discharge valve system in a rolling piston compressor with different compressor frequency and operating conditions. The flow coefficients of the discharge valve system were determined by both experiments and CFD simulation for specifically configured condition with varying discharge port diameter, valve lift height and valve shape to consider operating and geometric conditions. The experiment and CFD simulation were conducted under the incompressible flow and steady state. Ambient air was used as a working fluid. In order to verify the reliability of CFD simulation, the computational results were compared with those of experiment. The flow coefficient maps for each discharge valve system could be obtained from the computational results. The functional flow coefficient model was derived from the maps. It was applied to compressor performance simulation to calculate mass flow rate at the discharge valve system as a function of diameter of discharge port and lift height of the valve. Energy Efficiency Ratio(EER) obtained from the functional flow coefficient model with varying compressor frequency showed good agreement with experimental data. The Functionalization of flow coefficient may improve the precision of compressor performance simulation

R-parity Violation and Semileptonic Decays of B-meson

We investigate the effects of R-parity violation on the semileptonic decays of B-meson in the minimal supersymmetric standard model with explicit R-parity violation and discuss its physical implications. We find that the semileptonic decays of B-meson can be largely affected by the R-parity violation.Comment: 10 pages, LaTex file, no figure. References and a table are added. Tables are improve

Hepatocellular Carcinoma after Transcatheter Arterial Chemoembolization: Difficulties on Imaging Follow-up

ope

Laparoendoscopic Single-Site Surgery (LESS) for Excision of a Seminal Vesicle Cyst Associated with Ipsilateral Renal Agenesis

We report a case of laparoendoscopic single-site surgery (LESS) for a symptomatic left seminal vesicular cyst and ipsilateral renal agenesis. A 49-year-old man presented with a 1-year history of severe irritation upon voiding and intractable, recurrent hematospermia. A computed tomography scan showed a 68×41×38 mm sized left seminal vesicular cyst with ipsilateral renal agenesis. LESS was performed successfully to treat the seminal vesicle cyst. The total operative time was 125 minutes, and blood loss was minimal. The patient was discharged from the hospital on the second postoperative day

A new strategy for integrating abundant oxygen functional groups into carbon felt electrode for vanadium redox flow batteries

The effects of surface treatment combining corona discharge and hydrogen peroxide (H2O2) on the electrochemical performance of carbon felt electrodes for vanadium redox flow batteries (VRFBs) have been thoroughly investigated. Ahigh concentration of oxygen functional groups has been successfully introduced onto the surface of the carbon felt electrodes by a specially designed surface treatment, which is mainly responsible for improving the energy efficiency of VRFBs. In addition, the wettability of the carbon felt electrodes also can be significantly improved. The energy efficiency of the VRFB cell employing the surface modified carbon felt electrodes is improved by 7% at high current density (148 mA cm(-2)). Such improvement is attributed to the faster charge transfer and better wettability allowed by surface-active oxygen functional groups. Moreover, this method is much more competitive than other surface treatments in terms of processing time, production costs, and electrochemical performance.

A new strategy for integrating abundant oxygen functional groups into carbon felt electrode for vanadium redox flow batteries

The effects of surface treatment combining corona discharge and hydrogen peroxide (H2O2) on the electrochemical performance of carbon felt electrodes for vanadium redox flow batteries (VRFBs) have been thoroughly investigated. A high concentration of oxygen functional groups has been successfully introduced onto the surface of the carbon felt electrodes by a specially designed surface treatment, which is mainly responsible for improving the energy efficiency of VRFBs. In addition, the wettability of the carbon felt electrodes also can be significantly improved. The energy efficiency of the VRFB cell employing the surface modified carbon felt electrodes is improved by 7% at high current density (148 mA cm−2). Such improvement is attributed to the faster charge transfer and better wettability allowed by surface-active oxygen functional groups. Moreover, this method is much more competitive than other surface treatments in terms of processing time, production costs, and electrochemical performance

Spotted Fever Group and Typhus Group Rickettsioses in Humans, South Korea

Multiplex-nested PCR and sequencing analysis indicated rickettsialike agents in serum specimens from febrile patients