Enhanced airborne sound absorption effect in poly(vinylidene fluoride)/(K0.5Na0.5)NbO3-nanofiber composite foams

Introducing electrical conductive function to discharge local piezoelectric effect is found effective for improving airborne sound absorption performance. In this work, instead of conductive fillers, a composite with two piezoelectric materials with opposite piezoelectric responses was explored aiming at enhanced sound absorption effect. Open-cell poly(vinylidene fluoride)/(K_0.5Na_0.5)NbO₃ (PVDF/KNN)-nanofiber composite foams were proposed and investigated for airborne sound absorption purpose. Structural and thermal analyses showed that the KNN nanofibers were well dispersed in the PVDF matrix and enhanced the degree of crystallinity of polar phase of PVDF. Significantly enhanced airborne sound absorption over a broad frequency range was observed in the PVDF/KNN-nanofiber composite foams, with increasing KNN nanofibers. One possible mechanism for the improved sound absorption with the piezoelectric KNN nanofibers with positive piezoelectric coefficient added in the PVDF matrix with negative piezoelectric coefficient is that electrical discharge could be facilitated for energy dissipation with the opposite charges generated through the piezoelectric effects in the two phases with opposite polarity. The experimental results show that the open-cell PVDF/KNN-nanofiber composite foams are promising for broadband airborne sound absorption application, and our analysis shed a light on the strategy in designing piezoelectric composite foam with high sound absorption performance.     

Editorial: Triple Helix and innovation in Asia using scientometrics,webometrics, and informetrics

There is a burgeoning interest among academic scientists and policy-makers in the development and employment of TH (Triple Helix) and WSI (Webometrics, Scientometrics, and Informetrics) research methods. However, the international literature has not systematically examined TH and WSI approaches in an Asian context. Furthermore, previous literature published in international journals does not adequately address the social forces shaping TH development in Asia. Therefore, the purpose of this special issue is to bring researchers together to discuss university-industry-government (U-I-G) relations and innovation diffusion in Asia employing WSI alongside other methods.     

Modeling and optimization of existing beam port facility of PSBR

Due to inherited design issues with the current arrangement of beam ports (BPs) and reactor core-moderator assembly in The Perm State Breazeale Reactor (PSBR), the development of innovative experimental facilities utilizing neutron beams is extremely limited. Therefore, a study has started to examine the existing BPs for neutron and gamma outputs and develop a new core-moderator location and BP geometry in PSBR. Although 7 BPs are placed in PSBR, 2 of them are using currently. In this study BP 4, one of the currently being used BP, is examined. With changing the location of the BP 4 and structure of the core assembly, some artificial models are developed and compared with the original model.     

Disposition of the flavonoid quercetin in rats after single intravenous and oral doses

The pharmacokinetic and mean time tissue distribution parameters, after a single 50-mg/kg dose of quercetin administered as intravenous bolus, oral solution, and oral suspension, were determined using rat as an animal model. Following intravenous administration, the elimination rate constant and the elimination half-life were found to be 0.0062 min^-1 and 111 min, respectively. Examining the mean time tissue distribution parameters reflected a strong binding affinity of the drug molecules to both plasma and tissue proteins. In addition, the low permeability rate of drug molecules in the peripheral system was demonstrated. Following the oral administration of the drug, the extent of absorption was greater from solution than from suspension. Moreover, the solution showed a shorter T_max and a higher C_max than suspension. The absolute bioavailability for the solution was 0.275 and that for suspension was 0.162. The mean residence time (MRT) and the mean absorption time (MAT) were higher for suspension, reflecting the need for dissolving the drug in order to be absorbed. The mean (in-vivo) dissolution time (MDT_in-vivo) was 34.5 min. Thus, an oral quercetin formulation that can readily form a drug solution in the gastrointestinal tract may enhance the absorption of the drug.     

Performance Characteristics of Alpha-Particle Corona-Streamer Counter

Alpha-particle wire-plate corona counters in air can be operated either in the spark or in the corona-streamer modes. The streamer mode is preferred over the spark mode since it has the advantages of low dead time and the absence of electrode corrosion by sparking. An analysis of the alpha-particle corona-streamer counter is described. The alpha-particle triggered corona pulse characteristics (e.g., pulse shape, amplitude, repetition rate, etc.) are calculated. Not only the pulse characteristics but also the inception voltages of the corona-mode regime are determined. For each wire diameter, a transition gap length between corona and spark modes exists, which is termed ``critical gap length.' The counting rate characteristics have been obtained for wire diameters 0.05-0.1 mm. All the theoretical findings are confirmed by experiment.     

Process monitoring in real time: Empirical bayes approach—discrete case

In this paper an empirical Bayes model is developed to monitor and analyse discrete data generated in a manufacturing process for printed circuit boards. A key feature of this analysis is the use of the current observation at time t and the posterior estimates of the distribution of the proportion nonconforming at time t – 1 to obtain a new, updated estimate of the posterior distribution at time t. The derived approach is widely applicable to statistical process control and provides a simple and fast algorithm for updating.     

The effect of cross-talk on MRI lesion numbers and volumes in multiple sclerosis using conventional and turbo spin-echo

A case of ovarian mixed germ cell tumor in a 44-year-old woman was examined. The tumor was well circumscribed, measured 15 x 11 x 10 cm and appeared solid and partly cystic on the cut surface. Light microscopic examinations revealed that the tumor was composed of four different neoplastic germ cell elements, intermingled with each other. They are: (i) choriocarcinoma, immunohistochemically positive for human placental lactogen (hPL) and human chorionic gonadotropin (hCG); (ii) dysgerminoma, positive for placental alkaline phosphatase; (iii) endodermal sinus tumor positive for alpha-fetoprotein (AFP); and (iv) mature teratoma. Among these histological types, dysgerminoma occupied more than 50% of the neoplasm. The patient was diagnosed as a stage la ovarian mixed germ cell tumor and was subsequently treated with chemotherapy. A second-look laparotomy after completion of chemotherapy revealed no residual tumors in the abdomen and the patient is alive and well 15 months after operation. This is the fourth reported case of ovarian mixed germ cell tumor arising in patients over 40 years old.