Separation and purification of hyaluronic acid by glucuronic acid imprinted microbeads

The purification of hyaluronic acid (HA) is relatively significant to use in biomedical applications. The structure of HA is formed by the repetitive units of glucuronic acid and N-acetyl glucosamine. In this study, glucuronic acid-imprinted microbeads have been supplied for the purification of HA from cell culture (Streptococcus equi). Histidine-functional monomer, methacryloylamidohistidine (MAH) was chosen as the metal-complexing monomer. The glucuronic acid-imprinted poly(ethyleneglycoldimethacrylate-MAH-Copper(II)) [p(EDMA-MAH-Cu²⁺)] microbeads have been synthesized by typical suspension polymerization procedure. The template glucuronic acid has been removed by employing 5 M methanolic KOH solution. p(EDMA-MAH-Cu²⁺) microbeads have been characterized by elemental analysis, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) images and swelling studies. Moreover, HA adsorption experiments have been performed in a batch experimental set-up. Purification of HA from cell culture supernatant has been also investigated by determining the hyaluronidase activity using purified HA as substrate. The glucuronic acid imprinted p(EDMA-MAH-Cu²⁺) particles can be used many times with no significant loss in adsorption capacities. Also, the selectivity of prepared molecular imprinted polymers (MIP) has been examined. Results have showed that MIP particles are 19 times more selective for glucuronic acid than N-acetylglucose amine.     

Multi-rule Multi-objective Simulated Annealing Algorithm for Straight and U Type Assembly Line Balancing Problems

The task of balancing of assembly lines is of considerable industrial importance. It consists of assigning operations to workstations in a production line in such a way that (1) no assembly precedence constraint is violated, (2) no workstations in the line takes longer than a predefined cycle time to perform all tasks assigned to it, and (3) as few workstations as possible are needed to perform all the tasks in the set. This paper presents a new multiple objective simulated annealing (SA) algorithm for simple (line) and U type assembly line balancing problems with the aim of maximizing “smoothness index” and maximizing the “line performance” (or minimizing the number of workstations). The proposed algorithm makes use of task assignment rules in constructing feasible solutions. The proposed algorithm is tested and compared with literature test problems. The proposed algorithm found the optimal solutions for each problem in short computational times. A detailed performance analysis of the selected task assignment rules is also given in the paper.     

Noise Figure Reduction in Externally Modulated Analog Fiber-Optic Links

An octave-bandwidth microwave photonic link with a third-order limited spurious-free dynamic range of 121 dB in a 1-Hz bandwidth has been demonstrated. The link noise figure of 9 dB at a modulation frequency of 2 GHz was achieved by using a bias-shifted Mach-Zehnder modulator with an optical input power of 500 mW. This level of performance was realized without electronic or optical linearization     

Development of a framework for customer co-creation in NPD through multi-issue negotiation with issue trade-offs

In complex product design environments, new product development (NPD) becomes all about trade-offs and therefore trade-off management gets an important responsibility for designers. Correspondingly, in these environments, customer co-creation in NPD requires multi-issue negotiation with issue trade-offs. However, there is no study researching customer co-creation in NPD through multi-issue negotiation with issue trade-offs according to our best knowledge. This study presents a framework for customer co-creation in NPD through a multi-issue negotiation mechanism, namely; Modified Even-Swaps, to fill this gap. This mechanism uses a modified version of Even-Swaps method, that finds differences among alternatives and utilizes the differences for assessing the value of multi-issue offers, and that includes a fuzzy-inference-system for bargaining on several issues simultaneously. In the proposed framework, customers are represented by “lead-user”. Thus, negotiation is performed between lead-user and designer. In order to show how the framework works, an illustrative example is also presented.     

Solving fuzzy multiple objective generalized assignment problems directly via bees algorithm and fuzzy ranking

In this paper, a direct solution approach for solving fuzzy multiple objective generalized assignment problems is proposed. In the problem, the coefficients and right hand side values of the constraints and the objective function coefficients are defined as fuzzy numbers. The addressed problem also has a multiple objective structure where the goals are determined so as to minimize the total cost and the imbalance between the workload of the agents. The direct solution approach utilizes the fuzzy ranking methods to rank the objective function values and to determine the feasibility of the constraints within a metaheuristic search algorithm, known as bees algorithm. Different fuzzy ranking methods, namely signed distance, integral value and area based approach are used in bees algorithm. For the computational study, the effects of these fuzzy ranking methods on the quality of the solutions are also analyzed.     

Modified self-organising maps with a new topology and initialisation algorithm

Mapping quality of the self-organising maps (SOMs) is sensitive to the map topology and initialisation of neurons. In this article, in order to improve the convergence of the SOM, an algorithm based on split and merge of clusters to initialise neurons is introduced. The initialisation algorithm speeds up the learning process in large high-dimensional data sets. We also develop a topology based on this initialisation to optimise the vector quantisation error and topology preservation of the SOMs. Such an approach allows to find more accurate data visualisation and consequently clustering problem. The numerical results on eight small-to-large real-world data sets are reported to demonstrate the performance of the proposed algorithm in the sense of vector quantisation, topology preservation and CPU time requirement.     

Combining molecular imprinted nanoparticles with surface plasmon resonance nanosensor for chloramphenicol detection in honey

The focus of this article is to develop a surface plasmon resonance (SPR) nanosensor to determine chloramphenicol (CAP) using the molecularly imprinted nanoparticles. The CAP imprinted nanoparticles were prepared by miniemulsion polymerization method. Then, the nanoparticles were attached onto the SPR nanosensor surface via temperature‐controlled evaporation. Surface characterization studies were performed with atomic force microscopy and contact angle measurements. Kinetic studies were performed with CAP solutions in the concentration range of 0.155–6.192 nM. Florphenicol (FLP) and thiamphenicol (TAP) having similar chemical structures to the template (i.e., CAP) were chosen as competitors to determine selectivity of the nanoparticles. Selectivity constants were observed as 8.86 for CAP/TAP and 8.36 for CAP/FLP. The detection limit was calculated as 40 ng/kg honey sample. In the light of these results, it was emphasized that the SPR nanosensor is able to recognize CAP selectively and has a potential for real‐time CAP detection in honey sample. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Scheduling and sequencing of rubber compounds on banbury mixers in a tyre company

Scheduling and sequencing compounds on banbury mixers is a daily production planning function in a tyre company. The current scheduling procedures are based on experience. A number of factors, such as, capacity, cost, time, speed, set-up of mixers, compound changeovers, density and demand of compound, have to be considered during planning. In this paper, we propose a two-stage approach to this problem. This approach can be easily computerised to aid the personnel in the planning function. An example, considering actual data obtained from the company, is used to illustrate the approach. The current scheduling practice by company personnel, as inferred from past record, is also reported.     

Roof pond cooling of buildings in hot arid climates

The weather in Baghdad, Iraq is hot dry in the summer while water is plentiful and cheap. These are conditions which encourage the use of evaporative cooling. A building with one space in it was used to test the effect of a roof pond which was ventilated mechanically for summer cooling. Thermal measurements were taken for the room in normal conditions without a pond, with a lone pond and no mechanical ventilation, and then finally with mechanically forced ventilation. The results showed a marked improvement in the space temperature with a significant reduction during the peak time outside temperatures at 3 O’clock reaching 6.0 °C between the room without the pond and with a ventilated one and 6.5° at 18:00 during peak inside temperatures. The study also showed that improvements would be better in real-life conditions where exterior wall area is less than the test room.