A Ho(III) potentiometric polymeric membrane sensor based on a new four dentate neutral ion carrier

In this research, we report a new Ho^3 +-PVC membrane electrode based on N-(4,5-dimethyl-2-(picolinamido)phenyl)picolinamide (H₂Me₂bpb) as a suitable ion carrier. Poly vinylchloride (PVC)-based membrane composed of H₂Me₂bpb with oleic acid (OA) as anionic additives, and o-nitrophenyloctyl ether (NPOE) as plasticized solvent mediator. The sensor exhibits a Nernstian slope of 20.1 ± 0.2 mV decade^? 1 over the concentration range of 1.0 × 10^? 6 to 1.0 × 1^? 2 mol L^? 1, and a detection limit of 5.0 × 10^? 7 mol L^? 1 of Ho^3 + ions. The potentiometric response of the sensor is independent of the solution pH in the range of 3.5–9.4. It has a very short response time, in the whole concentration range (< 10 s), and can be used for at least eight weeks. The proposed electrode shows a good selectivity towards Ho^3 + ions over a wide variety of cations, including alkali, alkaline earth, transition and heavy metal ions. To assess its analytical applicability the proposed Ho^3 + sensor was successfully applied as an indicator electrode in the titration of Ho^3 + ion solutions in certified reference materials, alloy samples and for the determination of the fluoride ion in two mouthwash preparations.     

Polyaniline/Vanadium oxide composites: An effective control in morphology by varying reactant concentrations

A one pot synthesis protocol is presented for the realization of organic/inorganic hybrid nanostructures comprised of polyaniline and vanadium oxide. The polyaniline/vanadium oxide hybrid morphology is tailored by controlling the relative concentration of reactants which resulted in diverse morphologies ranging from nanorods, combined nano/microrods to porous nano/microspheres. Temporal evolution of morphology is investigated to elucidate the formation mechanism in detail. The prepared composites exhibit enhanced thermal stability in comparison to pure polyaniline which may be attributed to the strong chemical combination of vanadium oxide and polyaniline within the composites as prevailed by FTIR and TGA analysis of the products. This simple and controllable approach for synthesizing the organic/inorganic hybrid material should have future applications in energy storage devices, sensors and many more.     

Light core and intelligent edge for a flexible, thin-layered, and cost-effective optical transport network

We present a new optics-based transport architecture that emulates fast switching in the network core via emerging fast tunable lasers at the network edge, and bypasses the need for fast optical switching and buffering. The new architecture is capable of handling both asynchronous and synchronous traffic, for dealing with various bandwidth granularities and responding to dynamic changes in end-to-end traffic demands. The architecture also reduces the amount of layering in the transport network by eliminating packet and TDM switching, keeps the network core light (lightweight and transparent), and pushes intelligence to the network edge. We discuss technical challenges that arise in the new architecture and describe possible approaches to address them.     

Multiobjective optimization of an industrial grinding operation using elitist nondominated sorting genetic algorithm

The elitist version of nondominated sorting genetic algorithm (NSGA II) has been adapted to optimize the industrial grinding operation of a lead-zinc ore beneficiation plant. Two objective functions have been identified in this study: (i) throughput of the grinding operation is maximized to maximize productivity and (ii) percent passing of one of the most important size fractions is maximized to ensure smooth flotation operation following the grinding circuit. Simultaneously, it is also ensured that the grinding product meets all other quality requirements, to ensure least possible disturbance in the following flotation circuit, by keeping two other size classes and percent solid of the grinding product and recirculation load of the grinding circuit within the user specified bounds (constraints). Three decision variables used in this study are the solid ore flowrate and two water flowrates at two sumps, primary and secondary, each of them present in each of the two stage classification units. Nondominating (equally competitive) optimal solutions (Pareto sets) have been found out due to conflicting requirements between the two objectives without violating any of the constraints considered for this problem. Constraints are handled using a technique based on tournament selection operator of genetic algorithm which makes the process get rid of arbitrary tuning requirement of penalty parameters appearing in the popular penalty function based approaches for handling constraints. One of the Pareto points, along with some more higher level information, can be used as set points for the previously mentioned two objectives for optimal control of the grinding circuit. Implementation of the proposed technology shows huge industrial benefits.     

Duodenal atresia: a comparison of three modes of treatment

To determine the most successful mode of treatment, 33 consecutive cases of duodenal atresia treated by duodenoduodenostomy and not associated with other gastro-intestinal anomalies were analysed retrospectively. These patients have been placed in a nonrandomised fashion into one of three groups: Group A: Duodenostomy (side to side) with gastrostomy and transanastomotic feeding tube (n = 12); Group B: Duodenoduodenostomy (diamond shape) with jejunostomy feeding tube (n = 12); Group C: Duodenoduodenostomy (diamond shape) only (n = 9). A nasogastric tube was used in all cases. There was no difference between the groups for gestational age, birthweight, and age at operation. The outcome measures used to compare these groups were the time taken to achieve full preanastomotic feeds and the duration of hospital stay. There was no difference in time taken to achieve full pre-anastomotic feeds between Group A and Group B. Patients in Group C took significantly less time to achieve full pre-anastomotic feeds than either of the other two groups (p < 0.05, Mann-Whitney U). The duration of hospital stay was also significantly shorter for patients in Group C (median = 12 days) than for patients in either Group A or B (median = 24, 20 days respectively) (p < 0.05, Mann-Whitney U).     

Syndiotactic polymerization of styrene: Study of catalyst components and polymerization conditions

Syndiotactic polystyrene (s‐PS) was prepared using monotitanocene catalyst of cyclopentadienyl titanium trichloride (CpTiCl₃) activated by methylaluminoxane (MAO). Solution polymerization was carried out in toluene using different polymerization conditions. Syndiotacticity index (SI) between 68 and 91.6% was obtained. Increasing Al/Ti molar ratio shows an increase in both conversion percentage and SI. The conversion increased linearly with increasing Al/Ti molar ratio in the range studied. The conversion reached to an optimum value of about 65% at styrene/Al molar ratio of 2.83, while no regular behavior of SI was observed with changing the ratio. Effect of temperature of the range 50–80°C on polymerization was studied. The most favorable temperature for the polymerization regarding activity is 70°C; however SI decreased with temperature up to 80°C. H₂ value to 140 mL/100 mL solvent increased the productivity of the catalyst, however further increase of H₂ reduced the activity of the catalyst. Polymerization time of 15 to 125 min shows a decrease in activity. The decrease was sharper for about 30 min of polymerization than longer time. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2216–2221, 2006     

X-tolerant test response compaction

Larger, denser designs lead to more defects; higher quality requirements and new test methods lead to an explosion in test data volume. Test compression technique attempt to do more testing with fewer bits. This article summarizes one such method, X compact which addresses how unknowns the bane of compression and logic BIST techniques are eliminated. DFT engineers must spend serious effort to minimize Xs in future designs. It is impossible to eliminate all Xs. X-tolerant response compactors are necessary for tolerating residual Xs to enable massive compaction with practically no impact on test quality. X-compactors are mainly useful for test compression purposes and provide up to 80 times the test response compaction of traditional scan. X-tolerant signature analyzers extend the X-compact concept to incorporate time compaction, thereby tolerating thousands of Xs and reducing test response data volume by 50 to 2,000 times relative to traditional scan. These signature analyzers are extremely beneficial for BIST because Xs can easily corrupt traditional MISR-based BIST signature analyzers. X-tolerant response compactors also enable efficient diagnosis essential to fast yield-learning.     

Robust dynamic admission control for unified cell and call QoS instatistical multiplexers

The design of connection admission control (CAC) for a simple Markovian model of a multiservice statistical multiplexer is considered. The paper begins by laying the foundation through several fundamental analytic concepts, such as a semi-Markov decision process formulation of the design problem and time scale decomposition, before progressively leading up to real-world requirements, like robustness and simplicity of design. Several numerical illustrations are given. The salient contributions of the paper are as follows. (1) A unified treatment of multiclass cell and call QoS. (2) A CAC design which is robust, fair, and efficient. (3) Simplicity in the CAC design, together with an evaluation of the tradeoff with performance. (4) An analytic technique for computing the feasibility region in the space of call arrival rates where some control exists to satisfy QoS. (5) The discovery of near linearity of the boundary of the feasible region, which is then used to decompose the design problem. (6) A unified treatment of aggressive and conservative forms of CAC, the latter being conventional and the former yielding better call level performance. (7) An effective bandwidth definition based on the aggressive form of CAC, which influences the CAC design. (8) A demonstration of the beneficial impact on performance of cell level control. (9) An asymptotic theory of the joint behavior of cell loss and call blocking. (10) A rigorous development of time scale decomposition. (11) A numerical evaluation of the accuracy of the notion of nearly completely decomposable Markov chains     

On Blind Timing Acquisition and Channel Estimation for Wideband Multiuser DS-CDMA Systems

The problems of blind timing acquisition and channel estimation for DS-CDMA signals in multipath fading channels are investigated. Using only the spreading code of the desired user, methods based on QR decompositions are proposed. These methods perform comparably or even better than subspace based methods with an order lower complexity. Furthermore, the methods exhibit significantly more robustness to channel order mismatch. Based on the acquired timing information, channel estimation algorithms are also developed which are competitive with the previously proposed subspace based channel estimation algorithms. In addition, a channel order estimation algorithm is proposed for the scenario where the order is unknown. Performance of the proposed algorithms is evaluated through simulation and comparison to asymptotic Cramér-Rao bounds.     

Rapid identification of subtype-selective agonists of the somatostatin receptor through combinatorial chemistry

Nonpeptide agonists of each of the five somatostatin receptors were identified in combinatorial libraries constructed on the basis of molecular modeling of known peptide agonists. In vitro experiments using these selective compounds demonstrated the role of the somatostatin subtype-2 receptor in inhibition of glucagon release from mouse pancreatic alpha cells and the somatostatin subtype-5 receptor as a mediator of insulin secretion from pancreatic beta cells. Both receptors regulated growth hormone release from the rat anterior pituitary gland. The availability of high-affinity, subtype-selective agonists for each of the somatostatin receptors provides a direct approach to defining their physiological functions.