Comparison of Ion Exchange Performance of Polystyrene Nanofiber Cation Exchanger and Glass Fibers Coated with Poly(styrene‐co‐divinylbenzene)

Polystyrene nanofiber ion exchangers (PSNIE) were prepared by electrospinning from solutions of dissolved polystyrene followed by sulfonation processes. Coating and sulfonation have been used to modify glass fiber surfaces with polystyrene to produce cation exchange fibers (CEF). In this paper, new experimental results investigating the performance of PSNIE and CEF are presented in relation to the relevant parameters (ion exchange capacity (IEC), water uptake, and surface morphology). The IEC and water uptake of the PSNIE and CEF is depended upon the sulfonation time. The PSNIE sample with 30 min sulfonation time showed the maximum IEC of 3.74 mmol/g‐dry‐PSNIE and water uptake of 0.77 g H₂O/g‐dry‐PSNIE. The IEC and water uptake of CEF reached up to 3.61 mmol/g‐CEF and 0.25 g H₂O/g‐dry‐CEF.     

Study of bending-induced strain effects on MuGFET performance

The impact of stress induced by biaxial mechanical bending on multiple-gate FET (MuGFET) performance is studied. For relatively low levels of bending-induced surface strain (/spl sim/ 0.1%), significant enhancements in the driving current can be achieved and maintained with gate-length scaling. This makes package strain a potentially attractive approach to enhancing MuGFET-based CMOS performance at low cost. For bending-induced strain, the enhancements in electron mobility and [110] hole mobility are well predicted by the piezoresistance model using the coefficients for bulk-Si, but the impact of stress on (100) hole mobility is more complex.     

Anandamide synthesis is induced by arachidonate mobilizing agonists in cells of the immune system

The hypothesis that the capability of agents to mobilize arachidonic acid (AA) could predict increased anandamide (ANA) synthesis in a macrophage cell line has been examined. Lipopolysaccharide (LPS), platelet-activating factor (PAF) and cannabinoids such as Delta9-tetrahydrocannabinol (THC) and anandamide were all found to be agonists for the release of AA and led to increased ANA synthesis in RAW264.7 mouse macrophage cells. Nitric oxide, in contrast, stimulated AA release without raising ANA levels. ANA stimulation of its own synthesis indicates the existence of a positive feedback mechanism. The possible involvement of the CB2 receptor in THC-mediated AA release and ANA synthesis is addressed using the antagonist SR144528. ANA synthesis is also increased by the combination of calcium ionophore and indomethacin, suggesting that ANA is metabolized by a cyclooxygenase in this system. The data imply that ANA could play a role in the response of the immune system to cannabinoids and bacterial endotoxins and that AA mobilization is a predictor for increased ANA synthesis.     

An evaluation of vesical urodynamics before renal transplantation and its effect on renal allograft function and survival

This prospective study investigated the urodynamics of the urinary bladder prior to renal transplantation in 57 patients and related this to graft function and transplantation outcome. The study demonstrated a clear deterioration in the pretransplant urodynamic characteristics in all subgroups, with male patients in the hemodialysis group (HD) showing a more substantial decline: 1st sensation volume (ml) in male HD patients = 112 (120) vs. 171 (173) in male CAPD patients, P < 0.05; and corresponding average flow rate for same groups 3 (3) ml/sec vs. 5 (5) ml/sec, P < 0.05. Figures are median (interquartile range). We have identified a subgroup of patients with a small bladder capacity (less than 100 ml) who have a reduced graft survival (55% vs. 92% for bladders larger than 100 ml at 2 years) apparently unrelated to immunological processes.     

Resynchronization and controllability of bursty service requests

There is an increasing prevalence of interactive Web sessions in the Internet. These are mostly short-lived TCP connections that are delay-sensitive and have transfer times dominated by TCP backoffs, if any, during connection establishment. Unfortunately, arrivals of such connections at a server tend to be bursty, and can trigger multiple retransmissions, resulting in long average client-perceived delays. Traditional traffic control mechanisms, such as token bucket filters, are designed to complement admission control mechanisms, by regulating throughput, bounding service times, and protecting systems from overload. However, they cannot control connection-establishment delays, and thus, do not provide effective control of client-perceived delays. We first present the surprising discovery of a resynchronization property of retransmitted requests that exacerbates client-perceived delays when traditional control mechanisms are used. Then, we introduce a novel, multistage filtering scheme called Abacus Filters (AFs) that limits the client-perceived delay while maximizing server throughput even in the case of bursty connection arrivals. Analysis of delay-control properties of various filtering mechanisms is presented, along with a detailed performance evaluation. AFs are shown to provide tight delay control and better complement traditional admission control policies.     

Burr formation during micro via-hole punching process of ceramic and PET double layer sheet

Nowadays, recent electronic equipments are becoming smaller, multi-functional, and more complex. Similarly, low temperature co-fired ceramic (LTCC) has been emerged as a promising technology in the packaging industry. It consists of a multi-layer ceramic sheet, and a three-dimensional circuit. The via hole formation in LTCC plays an important role in providing an electric path for the interconnection between circuits. Therefore, via hole quality has a very important role for ensuring the performance of LTCC product. Via holes are formed on the green sheet that consists of ceramic (before sintering) layer and PET (Polyethylene terephthalate) layer. In this paper, we will discuss about the correlation between hole quality and process condition such as ceramic thickness, tool size, etc. The shear behavior of double layer sheet by micro hole punching which is different from that of single layer one will also be discussed.     

New antiwindup PI controller for variable-speed motor drives

The windup phenomenon appears and results in performance degradation when the proportional-integral (PI) controller output is saturated. A new antiwindup PI controller is proposed to improve the control performance of variable-speed motor drives, and it is experimentally applied to the speed control of a vector-controlled induction motor driven by a pulsewidth modulated (PWM) voltage-source inverter (VSI). The integral state is separately controlled, corresponding to whether the PI controller output is saturated or not. The experimental results show that the speed response has much improved performance, such as small overshoot and fast settling time, over the conventional antiwindup technique. Although the operating speed command is changed, similar control performance can be obtained by using the PI gains selected in the linear region     

Refractive‐index matching between liquid crystals and photopolymers

Abstract— Refractive indices of two photocurable polymers, NOA65 and NOA81 (Norland Optical Adhesive), and two series of Merck liquid crystals, E‐series (E44, E48, and E7) and BL‐series (BL038, BL003 and BL006), and two UCF high‐birefringence liquid‐crystal mixtures were measured using an Abbe refractometer in the visible spectral region and 15–55°C temperature range. Some liquid crystals have excellent index matching with NOA65 in the red, while some fit better in the blue spectral region. To validate this index‐matching property found in the material level, we prepared some polymer‐dispersed liquid‐crystal devices. Good correlations between material and device performances are obtained.     

Feedforward control of the lateral position of a moving web using system identification

Many mathematical models have been developed to describe the lateral dynamics of a moving web, including Shelton's model. Experimental results in this study showed that the existing model does not fully describe the characteristic of the lateral dynamics for some typical operating conditions. An experimental model was derived by means of system identification using a well-known least-square method to improve the prediction capability of the lateral dynamics. A commercial guidance system usually has the proportional and integral control structure. Sometimes it may not eliminate the effect of periodic lateral disturbances efficiently which are transferred from upstream spans because the controller relying solely on feedback generates control action only when an output measurement signal differs from a reference value. However, if the disturbance is deterministic, a feedforward control structure may offer simple and effective disturbance rejection performance. In this paper, the lateral position of a web at the upstream span and the identified model of lateral dynamics for the span were used to estimate the effect of disturbance on the lateral dynamics of a moving web at the exit span of the guidance system. A feedforward controller was designed to reject the deterministic disturbance of lateral dynamics of a moving web. The disturbance rejection performance of the proposed controller was verified by computer simulation and experiments. These results showed that the proposed feedforward scheme with an improved mathematical model greatly improved control performance in overcoming the dynamic disturbance.