One-shot Process Research Articles

SYNTHESIS, CHARACTERIZATION AND APPLICATION OF A POLYURETHANE-BASED SUPPORT FOR IMMOBILIZING MEMBRANE-BOUND LIPASE

Abstract This study conducted an assessment of polyurethane foams that were synthesized by one-shot process and used as a low-cost support to immobilize Mucor circinelloides URM 4182 whole-cells presenting high lipolytic activity. Polyols with different molecular weights (1100 to 6000 g mol-1) were applied to synthesize the polymer matrix, and the agitation speed effect was used for controlling the average pore size of the investigated polyurethane foams. The physical and mechanical properties of the polymers were evaluated by standard test methods, and their morphology was identified by Scanning Electron Microscopy. The immobilization procedure efficiency was assessed by quantifying the capability of the matrices to attach the cells and the catalytic activity of the biocatalysts in both aqueous (olive oil hydrolysis) and non-aqueous media (ethanolysis of babassu oil) under single and consecutive batch runs. Although all synthesized matrices were suitable to immobilize the whole cells with high catalytic performance, a better set of parameters was attained when the polyol ether with molecular weight of 6000 g mol-1 and 1100 g mol-1 was used. Both matrices yielded immobilized biocatalysts with high hydrolysis and transesterification activities, and exhibited a satisfactory operational stability with 96% and 81% retention of their initial hydrolytic and transesterification activities after three consecutive batch runs.

Experimental-based dynamic calibration of the diesel air-path

An experimental study is presented of a novel dynamic calibration methodology applied to the air-path of a Jaguar Land Rover turbocharged diesel engine. The calibration is obtained in a one-shot process solely from data obtained from dynamic dynamometer testing, without any in-vehicle tuning. Although limited here to control of only boost pressure and exhaust gas recirculation rate with constraints on NOx and particle emissions, the methodology has the potential for a complete engine calibration including emission constrained optimisation of fuel consumption. The approach combines state space neural network (SSNN) modelling and optimisation to determine a feedforward Hammerstein-Wiener control map from the synthesised optimal control behaviour. The controller performance was verified by vehicle testing at the Jaguar Land Rover Test Track, Gaydon, UK. The outcome demonstrates a method for systematically obtaining dynamic control calibrations for good driveability and reduced emissions from limited dynamometer testing time without the need for manual tuning.

Photodegradation behavior of waterborne polyurethanes with different segment distributions and lengths

Abstract Waterborne polyurethanes with different segment distributions and lengths were synthesized by one-shot and/or prepolymer processes. The photodegradations were performed with a rotary UV photochemical reactor in water, and the chain scission degrees were investigated with a Dynamic light scattering (DLS) measurement. The photodegraded polyurethane dispersions were molded into films by a solvent-casting method and were studied with various measurements in detail. The dispersion particle of the one-shot polyurethane had defects in the outside phase because of heterogeneous distribution of the hard segment (HS), and the inner soft segment (SS) was intensely photodegraded by the UV irradiation. On the other hand, the HS of prepolymer polyurethane was homogeneously distributed, and higher photodegradation stability was shown. The photodegradation behavior of the prepolymer polyurethane was strongly affected by the SS length.

Preparation and Characterization of Magnetic Rigid Polyurethane Foam Reinforced with Dipodal Silane Iron Oxide Nanoparticles Fe3O4@APTS/GPTS

In this study, a new class of magnetic rigid polyurethane foams (PUFs) has been fabricated by one-shot process. Dipodal silane-coated magnetic nanoparticles (DScMNPs) was used as the magnetic nanoparticle and synthesized by functionalization of iron oxide nanoparticles by the prepared dipodal silane based on 3-aminopropyltriethoxysilane (APTS) and γ-glycidoxypropyltrimetoxysilane (GPTS) via sol-gel method. The synthesized DScMNPs were used up to 8.0% in the rigid polyurethane foam formulation and prepared foams were characterized. The chemical structure of DScMNPs was confirmed by proton nuclear magnetic resonance spectroscopy (1H NMR), Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM), respectively. Morphological, thermal and mechanical properties of the PU nanocomposites were studied by scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). Vibrating sample magnetometery (VSM) was also showed that the synthesized PU nanocomposites are super paramagnetic.

エチニルアントラセン誘導体の効率合成とオリゴマー合成への応用

Effective synthesis of ethynylanthracene derivatives as novel π-conjugated compounds and their applications to the synthesis of anthracene-acetylene oligomers are described. Ethynyl groups were introduced into anthracene moieties by cross-coupling reactions (Kumada-Tamao and Sonogashira couplings), addition-aromatization reactions, or double-elimination reactions from suitable starting materials. In some cases, the reaction integration techniques such as one-pot or one-shot processes were useful to simplify the experimental procedures. Diacetylene derivatives were synthesized by oxidative coupling of terminal alkynes or Sonogashira coupling. The desilylation and silylation of ethynylanthracene derivatives under appropriate conditions are important processes on preparation of unsymmetrical building units. Thus prepared building units were accumulated by Sonogashira coupling or oxidative coupling to synthesize cyclic oligomers ranging from trimers to dodecamers as well as 9,10-bis(phenylethynyl)anthracene oligomers. Each oligomer shows characteristic structural, stereochemical, and electronic properties depending on the number of anthracene units, the mode of connections, and the shape of anthracene units. Enantiomers of some chiral cyclic oligomers were successfully resolved by chiral HPLC.

Synthesis of rigid polyurethane foams with castor oil-based flame retardant polyols

A new method of introducing castor oil based flame-retardant polyols (COFPL) into polyurethane foams was explored in this paper. Castor oil was alcoholyzed with glycerol. And epoxidation of glycerolysis castor oil was carried out by formic acid and hydrogen peroxide (H2O2). The flame-retardant polyols were gotten though ring-opening reaction with diethyl phosphate. A novel castor oil-based polyurethane foam has been prepared by a one-shot process with and without COFPL. The structure of COFPL was characterized by FT-IR and 1HNMR and the two studies exhibited characteristic peaks for COFPL. The thermal degradation and fire behaviour of polyurethane foams were investigated by limiting oxygen index (LOI), cone calorimetry test and thermogravimetry analysis. It has been shown that although the content of P element is only about 3%, the fire retardant incorporated in the castor oil molecule chain increased thermal stability and LOI value of polyurethane foam can reach to 24.3% without any other flame retardant. The compression strength of polyurethane foam was also improved with the increase of flame-retardant polyols. Morphology of polyurethane foams was examined by scanning electron microscope (SEM) and found to be displayed the regular size and high percentage of close area of the cell. Therefore, rigid foams from castor oil-based flame retardant polyols appear suitable for a wide range of applications.

Research on One-Shot Process of Hot Extrusion Forming Technology for Aluminum Alloy Drill Pipe

Aluminum alloy drill pipe used in deep drilling has great potential and broad field of application. Unlike steel drill pipe production method, aluminum alloy drill pipe is manufactured using forward extrusion in the horizontal hydraulic extrusion press to extrud internal/external upset ends with variable cross-section, and form an assembly line to produce aluminum alloy drill pipe. In this experiment, using 55MN double-action extrusion press on 7075 aluminum alloy tubing to get variable cross-section on one-shot, the extruded pipe body are in good surface quality wihtout cracks, laying the foundation for the forming technology of variable cross-section of aluminum alloy drill pipe.

Thermoplastic polyurethane synthesis using POSS as a chain modifier

In this study, thermoplastic polyurethanes (TPUs) were synthesized using the one-shot process in solution. To obtain the samples n-phenylaminopropyl polyhedric oligomeric silsesquioxane (POSS) was added as a chain modifier during the synthesis in four different amounts. The samples were characterized by infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and capillary rheometry. FTIR confirm the TPU attainment due the absence of the band at ~2253 cm-1 suggesting a complete conversion of the isocyanate terminations. The TGA showed that incorporation of POSS decreased the rate of mass loss of TPU under isothermal conditions. The flexible phase showed an enhanced stability to temperature, probably due to increased phase separation between the rigid and flexible domains. The DSC showed that incorporation of 0.4 wt. (%) of POSS increased the glass transition temperature of the flexible phase. Moreover, addition of POSS modified the melting behaviour, providing samples with a higher melting enthalpy compared to neat TPU as a consequence of the formation of larger crystals. The capillary rheometry analysis revels that the POSS addition showed a clear tendency toward higher intrinsic viscosities as the amount of POSS was increased.

Synthesis of Magnetite/Amphiphilic Polymer Composite Nanoparticles as Potential Theragnostic Agents

This study describes the synthesis of magnetite/amphiphilic polymer composite nanoparticles that can be potentially used simultaneously for cancer diagnosis and therapy. The synthesis method was a one-shot process wherein magnetite nanoparticles were mixed with core-crosslinked amphiphilic polymer (CCAP) nanoparticles, prepared using a copolymer of a urethane acrylate nonionomer (UAN) and a urethane acrylate anionomer (UAA). The CCAP nanoparticles had a hydrophobic core and a hydrophilic exterior with both PEG segments and carboxylic acid groups, wherein the magnetite nanoparticles were coordinated and stabilized. According to DLS data, the ratio of UAN to UAA and the ratio of magnetite to polymer are keys to controlling the size and thus, the stability of the composite nanoparticles. The magnetic measurement indicated that the composite nanoparticles had superparamagnetic properties and high saturation magnetization. The preliminary magnetic resonance imaging showed that the particles produced an enhanced image even when their concentration was as low as 80 microg/ml.

Biodegradable polyhydroxybutyrate as a polyol for elastomeric polyurethanes

AbstractIn the proposed work, new elastomeric bio-polyol based polyurethanes (bio-PUs) with specific mechanical properties were prepared by a one-shot process without the presence of a solvent. Commercial non-degradable polyether polyol derived from petrochemical feed stock was partly (in the amount of 1 mass %, 5 mass %, and 10 mass %) substituted by the biodegradable polyhydroxybutyrate (PHB). Morphology of elastomeric PU composites was evaluated by scanning electron microscopy and mechanical properties of the prepared samples were obtained by both tensile measurements and prediction via the Mooney-Rivlin equation. Electron microscopy proved that the prepared materials have the character of a particle filled composite material, where PHB particles are regular with their size of about 1–2 μm in diameter. Tensile measurements demonstrated that the Young’s modulus, tensile stress at break, and tensile strain at break of each sample increase with the increase of the volume fraction of the filler. From the measured stress-strain data, the first and the second term of the Mooney-Rivlin equation were calculated. The obtained constants were applied to recalculate the stress-strain curves. It was found that the Mooney-Rivlin equation corresponds well with the stress-strain behavior of the prepared specimens.

Formation of bowtie-shaped excitation in a photonic-microfluidic integrated devices

Narrowly confining the beam intensity in a well-defined region in the center of cell flow is a necessary step to perform reliable flow cytometry testing but has so far not been achieved in a photonic–microfluidic integrated device.We were able to focus the excitation beam to a very narrow bowtie shape with a near uniform intensity across the flow stream for excitation for a flow cytometry application. Beam geometry was achieved by integrating a one-dimensional lens system with planar waveguides and a microfluidic channel on one substrate using one patterning material via a one-shot process. This letter reports the method used to achieve such shaped beams and the performance of the shaped beams. © 2011 National Research Council Canada & Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2583–2586, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26309

투습방수성 Polyurethane 나노섬유 Multi-Membrane의 제조

Polyurethane (PU) was synthesized by one-shot process and the PU nanofiber was prepared by electrospinning. In this study, electrospun PU multi-membranes were prepared with various coating thickness ratio of base resin to top resin, where the base resin contains melamine curing agent and acid catalyst and the top resin contains water-repellent agent of fluoro-carbon compounds. The PU nanofiber multi-membranes were analyzed by field-emission scanning electron microscopy, differential scanning calorimeter, breathability, tensile strenth, air permeability and water resistance. The results showed that the PU multi-membrane provided excellent waterproof and moisture permeability.

A solventless synthesis process of new UV-curable materials based on linseed oil

A new synthesis process of polymer materials based on vegetable oil has been developed. First, linseed oil was thermally polymerized in bulk at 300 °C under an inert atmosphere. Next, the obtained stand oil was functionalized in a two-step one-shot process without solvent in order to graft on some photopolymerizable groups. The first step consisted of a bulk reaction with maleic anhydride at 220 °C under an inert atmosphere. The grafted anhydride groups were then used in the second step as an anchor for grafting 2-hydroxyethylmethacrylate at room temperature. Finally, the materials were prepared by UV-curing of the modified linseed oil and then characterized. The obtained materials are flexible, hydrophobic and not biodegradable, and may have potential applications in flexible coatings.

Formation and characterization of an ideal excitation beam geometry in an optofluidic device

An optimal excitation beam shape is necessary to perform reliable flow cytometric analysis but has so far not been implemented in a photonic-microfluidic integrated (i.e. optofluidic) device. We have achieved this feature by integrating a 1D lens system with planar waveguides and microfluidic channel on a substrate using one patterning material via a one-shot process. In this paper, we report the method of design and the performance of specifically formed excitation regions shaped to be ideal for reducing double detections, improving SNR, and for reliable detection in a flow cytometry application. Demonstration of different sizes via changes to lens design shows the ability to control the width of the shaped beam according to a targeted detection.

Chemistry of Anthracene–Acetylene Oligomers. XIV. Convenient Synthesis of Anthrylethynes by Double Elimination Reaction from Aldehydes and Sulfones

Abstract Three dianthrylethynes and an anthracene–acetylene trimer were conveniently synthesized by double elimination reactions starting from anthraldehydes and [(phenylsulfonyl)methyl]anthracenes. In the optimal one-shot process, a THF solution of these substrates and diethyl chlorophosphate was treated with LiHMDS at room temperature to give the desired alkynes in excellent yields without chromatographic purification. The structure of one of the intermediate vinyl sulfones was determined by X-ray crystallography.

V-detector: An efficient negative selection algorithm with “probably adequate” detector coverage

This paper describes an enhanced negative selection algorithm (NSA) called V-detector. Several key characteristics make this method a state-of-the-art advance in the decade-old NSA. First, individual-specific size (or matching threshold) of the detectors is utilized to maximize the anomaly coverage at little extra cost. Second, statistical estimation is integrated in the detector generation algorithm so the target coverage can be achieved with given probability. Furthermore, this algorithm is presented in a generic form based on the abstract concepts of data points and matching threshold. Hence it can be extended from the current real-valued implementation to other problem space with different distance measure, data/detector representation schemes, etc. By using one-shot process to generate the detector set, this algorithm is more efficient than strongly evolutionary approaches. It also includes the option to interpret the training data as a whole so the boundary between the self and nonself areas can be detected more distinctly. The discussion is focused on the features attributed to negative selection algorithms instead of combination with other strategies.

One-shot entanglement generation over long distances in noisy quantum networks

We consider the problem of creating a long-distance entangled state between two stations of a network, where neighboring nodes are connected by noisy quantum channels. We show that any two stations can share an entangled pair if the effective probability for the quantum errors is below a certain threshold, which is achieved by a local encoding of the qubits and a global bit-flip correction. In contrast to the conventional quantum-repeater schemes, we do not need to store the qubits in quantum memory for a long time: our protocol is a one-shot process (i.e., the elementary entangled pairs are used only once) involving one-way classical communication. Furthermore, the overhead of local resources increases only logarithmically with the size of the network, making our proposal favorable to long-distance quantum communication.

Wavelet-based separation of nonlinear show-through and bleed-through image mixtures

This work addresses the separation of the nonlinear real-life mixture of images that occurs when a page of a document is scanned or photographed and the back page shows through. This effect can be due to partial paper transparency ( show-through) and/or to bleeding of the ink through the paper ( bleed-through). These two causes usually lead to mixtures with different characteristics. We propose a separation method based on the fact that the high-frequency components of the images are sparse and are stronger on one side of the paper than on the other one. The same properties were already used in nonlinear denoising source separation (DSS). However, we developed significant improvements that allow us to achieve a competitive separation quality by means of a one-shot processing, with no iteration. The method does not require the sources to be independent or the mixture to be invariant, and is suitable for separating mixtures such as those produced by bleed-through, for which we do not have an adequate physical model.

OFDM peak power reduction with simple amplitude predistortion

In this paper, we propose a new peak-to-average power ratio (PAPR) reduction algorithm for OFDM transmission. The algorithm is based on simple amplitude predistortion of a subset of the input symbol blocks, the predistorted symbols being selected according to a metric which measures their contribution to the output signal samples of large. magnitude. This metric-based algorithm is simple, highly flexible, and can be implemented as a one-shot process, although its performance can be further improved by iterating the process one or more times

Characterization of the polyurethane foam using alginic acid as a polyol

In this study, polyurethane foams (PUF) were prepared using alginic acid, glycerin, and poly(ethylene glycol) (PEG) as polyols, 1,6-hexamethylene diisocyanate (HDI) as a diisocyanate, and water as a foaming agent by one-shot process. Their structura, mechanical, and water-absorbing properties were investigated. The amount of alginic acid was varied up to 30 wt%. Fourier transform infrared (FT-IR) analysis showed that urethane linkage was formed by the reactions between −NCO groups of diisocyanate and −OH groups of all polyols used. Also urea linkage was formed by the reactions between −NCO groups of HDI and water or −COO− groups of alginic acid. The reaction times for cream forming increased with increasing alginic acid but foam structures were not formed when alginic acid content in polyols was above 30 wt%. The optical micrographs showed that the average cell size of PUF slightly increased with increasing alginic acid. However, the density of PUF decreased with alginic acid content. The compressive modulus of PUF decreased with increasing alginic acid content. In the mean time, the water absorbency of PUF increased with increasing alginic acid content.