bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrostatic‐induced interfacial assembly of enzymes with nanosheets: Controlled orientation and optimized activity
Authors: An Zhe , He Jing , Lu Shan , Yang Lan 
Published: March 2010

AbstractIn this work, an electrostatic‐induced interfacial assembly of porcine pancreatic lipase (PPL) with the nanosheets of layered double hydroxide (LDHNSs) is designed to rationally control the orientation of bound PPL. The PPL orientation in the bidimensional confinement spacing alters relying on the PPL loading, with the majority of active sites facing the LDH layer at low PPL loading and facing the adjacent protein molecule at high PPL loading. The biocatalytic activity of the bound PPL significantly depends on its orientation. Remarkable enhancement of the bio‐activity has been observed when the PPL/LDHNSs mass ratio is less than 9, and a maximum activity is met with at PPL/LDHNSs = 0.5. In addition, the thermal stability of PPL‐LDHNSs bioactivity has been obviously improved in comparison with soluble PPL. © 2010 American Institute of Chemical Engineers AIChE J, 2010
Comparison of real‐time methods for maximizing power output in microbial fuel cells
Authors: Woodward L. , Perrier M. , Srinivasan B. , Pinto R. P. , Tartakovsky B. 
Published: March 2010

AbstractMicrobial fuel cells (MFCs) constitute a novel power generation technology that converts organic waste to electrical energy using microbially catalyzed electrochemical reactions. Since the power output of MFCs changes considerably with varying operating conditions, the online optimization of electrical load (i.e., external resistance) is extremely important for maintaining a stable MFC performance. The application of several real‐time optimization methods is presented, such as the perturbation and observation method, the gradient method, and the recently proposed multiunit method, for maximizing power output of MFCs by varying the external resistance. Experiments were carried out in two similar MFCs fed with acetate. Variations in substrate concentration and temperature were introduced to study the performance of each optimization method in the face of disturbances unknown to the algorithms. Experimental results were used to discuss advantages and limitations of each optimization method. © 2010 American Institute of Chemical Engineers AIChE J, 2010
High‐throughput microporous tube‐in‐tube microreactor as novel gas–liquid contactor: Mass transfer study
Authors: Chen Jian‐Feng , Chen Gui‐Zi , Wang Jie‐Xin , Shao Lei , Li Peng‐Fei 
Published: March 2010

AbstractHigh‐throughput microporous tube‐in‐tube microchannel reactor (MTMCR) was first designed and developed as a novel gas–liquid contactor. Experimentally measured kLα in MTMCR is at least one or two orders of magnitude higher than those in the conventional gas–liquid contactors. A high throughput of 500 L/h for gas and 43.31 L/h for liquid is over 60 times higher than that of T‐type microchannel. An increase of the gas or liquid flow rate, as well as a reduction of the micropore size and annular channel width of MTMCR, could greatly intensify the gas–liquid mass transfer. The interfacial area, α, in MTMCR was measured to be as high as 2.2 × 105 m2/m3, which is much higher than those of microchannels (3400–9000 m2/m3) and traditional contactors (50–2050 m2/m3). The artificial neural network model was proposed for predicting α, revealing only an average absolute relative error of <5%. © 2010 American Institute of Chemical Engineers AIChE J, 2011
Greedy algorithm for scheduling batch plants with sequence‐dependent changeovers
Authors: Castro Pedro M. , Harjunkoski Iiro , Grossmann Ignacio E. 
Published: March 2010

AbstractThis article presents a new algorithm for scheduling multistage batch plants with a large number of orders and sequence‐dependent changeovers. Such problems are either intractable when solved with full‐space approaches or poor solutions result. We use decomposition on the entire set of orders and derive the complete schedule in several iterations, by inserting a couple of orders at a time. The key idea is to allow for partial rescheduling without altering the main decisions in terms of unit assignments and sequencing (linked to the binary variables) so that the combinatorial complexity is kept at a manageable level. The algorithm has been implemented for three alternative continuous‐time mixed integer linear programing models and tested through the solution of 10 example problems for different decomposition settings. The results show that an industrial‐size scheduling problem with 50 orders, 17 units distributed over six stages can effectively be solved in roughly 6 min of computational time. © 2010 American Institute of Chemical Engineers AIChE J, 2011
Formation of SiON networks from silsesquiazanes
Authors: Yokota Hirotaka , Imanari Noriko , Sugahara Yoshiyuki 
Published: March 2010

AbstractSilsesquiazanes bearing different groups [RSi(NH)1.5]n(R = C12H25, Ph, H) were hydrolyzed and the resulting products were characterized. [C12H25Si(NH)1.5]nwas hydrolyzed by heating in an autoclave with water at 120 °C for 16 h. [PhSi(NH)1.5]nwas hydrolyzed by heating with water at 50 °C for 16 h. [HSi(NH)1.5]nwas dispersed in water at room temperature to induce hydrolysis. In the cases of [C12H25Si(NH)1.5]nand [PhSi(NH)1.5]n, IR analysis showed that SiNHSi bonds remained and that terminal SiNH2bonds in silsesquiazane were preferentially hydrolyzed to form SiOH bonds or SiOSi bonds. Solid‐state29Si CP/MAS NMR analysis revealed the formation of a SiON network containing various Si environments. All the SiH and SiN bonds in [HSi(NH)1.5]n, on the other hand, were converted into SiO bonds. These results reveal that SiON networks can be formed from silsesquiazanes bearing dodecyl and phenyl groups under relatively moderate conditions. Copyright © 2010 John Wiley & Sons, Ltd.
Effect of drying techniques on extraction of Astragalus pieces
Authors: Qianqian Di , Junhong Yang , Jun Zhao 
Published: March 2010

AbstractTo investigate the effect of different drying techniques on the quality of Chinese herb medicine (CHM), drying experiments of Astragalus pieces after rehydration were carried out, and four different kinds of drying techniques viz microwave drying, freeze‐drying, vacuum drying and hot‐air drying, were examined in this paper. The microstructure of dried samples was characterized by means of scanning electron microscope (SEM), and the molecular weight distribution of Astragalus pieces extract was characterized by means of ultrafiltration. Results show that dehydrated rate by microwave drying is five times faster than those by others three drying techniques. The effective component content in the extract of sample dried by microwave drying, with the molecular weight of less than 4000 Da, is higher than those by other three drying techniques. Observations of the SEM images show that the microstructure of sample dried by microwave drying is much similar to that of raw Astragalus pieces, indicating that microwave technique helps keep the penetrability of inner transmission tissues and thin‐wall cell tissues, and benefits to the extraction of effective components of Astragalus pieces. Copyright © 2010 Curtin University of Technology and John Wiley & Sons, Ltd.
Hydroentanglement nonwoven filters for air filtration and its performance evaluation
Authors: Patanaik Asis , Anandjiwala Rajesh D. 
Published: March 2010

AbstractNew nonwoven filters are developed for air filtration application with the help of hydroentanglement bonding technique. Different types of nonwoven filters are produced by varying the hydroentanglement processing parameters. The changes in nonwoven filter properties after prolonged exposure to working conditions under cyclic compression play an important role in its long‐term performance characteristics. The performance of the developed filters are evaluated in terms of changes in pore characteristics, filtration parameters, and strength after cyclic compression and compared with the corresponding values before subjecting it to cyclic compression. The developed filter shows good performance characteristics for air filtration with low pressure drop and high efficiency in capturing micron and submicron size particles without any significant changes in its strength. Theoretical understanding of the fluid flow emerging from the nozzles during the hydroentanglement process is simulated by the computational fluid dynamics (CFD). Based on the fluid drag force and impact force of the water jets, a mechanism of fiber bonding is proposed. The impact force of the water jets and fluid drag forces plays an important role in the mechanism of fiber bonding. Nozzle condition also plays an important role in economizing this process. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Dynamic mechanical properties of oil palm microfibril‐reinforced natural rubber composites
Authors: Joseph Shaji , Appukuttan Sreekumar P. , Kenny Jose M. , Puglia Debora , Thomas Sabu , Joseph Kuruvilla 
Published: March 2010

AbstractThe dynamic mechanical properties of macro and microfibers of oil palm‐reinforced natural rubber (NR) composites were investigated as a function of fiber content, temperature, treatment, and frequency. By the incorporation of macrofiber to NR, the storage modulus (E') value increases while the damping factor (tan δ) shifts toward higher temperature region. As the fiber content increases the damping nature of the composite decreases because of the increased stiffness imparted by the natural fibers. By using the steam explosion method, the microfibrils were separated from the oil palm fibers. These fibers were subjected to treatments such as mercerization, benzoylation, and silane treatment. Resorcinol‐hexamethylenetetramine‐hydrated silica was also used as bonding agent to increase the fiber/matrix adhesion. The storage modulus value of untreated and treated microfibril‐reinforced composites was higher than that of macrofiber‐reinforced composites. The Tg value obtained for this microfibril‐reinforced composites were slightly higher than that of macrofiber‐reinforced composites. The activation energy for the relaxation processes in different composites was also calculated. The morphological studies using scanning electron microscopy of tensile fracture surfaces of treated and untreated composites indicated better fiber/matrix adhesion in the case of treated microfibril‐reinforced composites. Finally, attempts were made to correlate the experimental dynamic properties with the theoretical predictions. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and properties of hydrophilic segmented block copolymers based on poly(ethylene oxide)‐ran‐poly(propylene oxide)
Authors: IJzer A. C. , Arun A. , Reijerkerk S. R. , Nijmeijer K. , Wessling M. , Gaymans R. J. 
Published: March 2010

AbstractThe present article discusses the synthesis and various properties of segmented block copolymers with random copolymer segments of poly(ethylene oxide) and poly(propylene oxide) (PEO‐r‐PPO) together with monodisperse amide segments. The PEO‐r‐PPO contained 25 wt % PPO units and the segment presented a molecular weight of 2500 g/mol. The synthesized copolymers were analyzed by differential scanning calorimetry, Fourier transform infra‐red spectroscopy, atomic force microscopy and dynamic mechanical thermal analysis. In addition, the hydrophilicity and the contact angles (CAs) were studied. The PEO‐r‐PPO segments displayed a single low glass transition temperature, as well as a low PEO crystallinity and melting temperature, which gave enhanced low‐temperature properties of the copolymer. The water absorption values remained high. In comparison to mixtures of PEO/PPO segments, the random dispersion of PPO units in the PEO segments was more effective in reducing the PEO crystallinity and melting temperature, without affecting the hydrophilicity. Increasing the polyether segment length with terephthalic groups from 2500 to 10,000 g/mol increased the hydrophilicity and the room temperature elasticity. Furthermore, the CAs were found to be low 22–39° and changed with the crosslink density. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117:1394–1404, 2010
Synthesis of poly(D,L‐lactic acid) modified by cholic acid via direct melt copolycondensation and its characterization
Authors: Wang Zhao‐Yang , Zhao Hai‐Jun , Wang Qun‐Fang , Ye Rui‐Rong , Finlow David E. 
Published: March 2010

AbstractFrom D,L‐lactic acid and the natural functional molecule cholic acid (CA), the biodegradable material poly(D,L‐lactide–cholate) was synthesized via direct copolycondensation. For the CA/lactic acid (LA) molar feed ratio of 1/64, the optimal synthesis conditions were as follows: a prepolymerization time of 8 h, 0.3 wt % SnO catalyst, and melt copolycondensation for 8 h at 160°C, which gave a novel star‐shaped poly(D,L‐lactic acid) (PDLLA) modified by CA with the maximum weight‐average molecular weight of 5600 Da at a yield of 51.9%. The copolymer poly(D,L‐lactide–cholate) at different molar feed ratios was characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, gel permeation chromatography, differential scanning calorimetry, thermogravimetry, and X‐ray diffraction. Decreasing the molar feed ratio of CA/LA from 1/15 to 1/128 reduced the average number of CA units embedded in the copolymer from 4 to 1. With 1/15 CA/LA, the copolymer was not a star‐shaped polymer, and its weight‐average molecular weight was the biggest (weight‐average molecular weight = 12,700 Da, weight‐average molecular weight/number‐average molecular weight = 1.68). With 1/32 CA/LA, the copolymer with two CA units was not a star‐shaped polymer either. With 1/64, 1/100, and 1/128 CA/LA, the copolymer mainly had one CA unit core embedded as a normal star‐shaped PDLLA with four arms, and certain crystallinity could be detected. The novel direct copolycondensation method was simple and practical for the synthesis of the asymmetrical star‐shaped PDLLA material, and it was advantageous for this PDLLA material embedded in the special bioactive molecule CA to be applied in the field of drug delivery and tissue engineering. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Adsorption and recovery of nonionic polymers by neutralization of cellulose fiber surface charge via cationic polyamide‐epichlorohydrin resins
Authors: Hsieh Jeffery S. , Yoo Sukjoon 
Published: March 2010

AbstractNonionic copolymers, such as poly(1‐vinylpyrrolidone)‐polystyrene, have been used in the production of filtration membranes, catalysts, and sensors. However, their nonionic character and high solubility in water prevents their efficient recovery from waste streams. Cellulose fibers show potential as recovery agents because they are inexpensive, environmentally friendly, and have a large surface area per unit mass. However, due to the anionic nature of the cellulose fiber surface, their adsorptive behavior is often limited to cationic species. We have shown that low‐dosage application of a cationic polyamide‐epichlorohydrin resin can alter the fiber surface charge so as to provide more neutral surface area for the nonionic polymer to adsorb; furthermore, the adsorbed polyamide‐epichlorohydrin resin does not block the approach of poly(1‐vinylpyrrolidone)‐polystyrene. Single‐component adsorption of poly(1‐vinylpyrrolidone)‐polystyrene was on the order of 10−3 g/g; with polyamide‐epichlorohydrin resin adsorbed on the fiber, the adsorption increased one‐order of magnitude to 10−2 g/g. We believe this significant increase is caused by neutralization of fiber surface charge via polyamide‐epichlorohydrin resin, creating a surface more favorable for adsorption and recovery of nonionic species. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Purification, surface modification of coal ash silica and its potential application in rubber composites
Authors: Mahmood Nasir , Khan Mohammad Sohail , Khan Asad Ullah , Stöckelhuber Klaus Werner , Heinrich Gert 
Published: March 2010

AbstractThis article reports the purification and surface modification of coal ash silica and afterwards its utilization as reinforcing filler in solution‐styrene‐butadiene rubber/butadiene rubber (S‐SBR/BR). The coal ash silica free of unwanted metal ions/mineral oxides was obtained using phosphoric acid. The chemical composition of the purified coal ash silica in comparison to impure coal ash indicates the presence of characteristic hydroxyl functional group at 3440 cm−1 and an increase in the oxygen content as determined with the help of Fourier Transform Infrared and x‐ray photoelectron spectroscopy, respectively. The contact angle analysis shows that after purification the polar part of the surface energy increased to 17.5 from 12 m Jm−2. While the surface area increased to an order of magnitude, i.e., 11.6 to 110.5 m2 g−1. The modification of purified silica particles with bis(3‐triethoxysilylpropyl) tetrasulfane reveal the functionalization of hydroxyl to ‐Si‐O‐R groups as detected at 1560 cm−1. As a consequence, the modified silica based S‐SBR/BR composite resulted in improved mechanical properties due to enhanced silica‐rubber interaction. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
A comparative study of water dispersible polyaniline nanocomposites prepared by laccase‐catalyzed and chemical methods
Authors: Shumakovich G. P. , Vasil'eva I. S. , Morozova O. V. , Khomenkov V. G. , Staroverova I. N. , Budashov I. A. , Kurochkin I. N. , Boyeva J. A. , Sergeyev V. G. , Yaropolov A. I. 
Published: March 2010

AbstractA comparative study of chemical and enzymatic methods of aniline polymerization was carried out. Fungal laccase from Trametes hirsuta was used in the synthesis of polyaniline nanoparticles made with poly(2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid) (PAMPS). Template polymerization of aniline was carried out in aqueous buffer. It was shown that the laccase had high long‐term and operating stabilities under acidic condition favorable for synthesis of conducting polyaniline. UV‐vis, FTIR spectroscopy, and cyclic voltammetry analysis are used for the characterization of the polyelectrolyte complexes of polyaniline and PAMPS. The incorporation of the polymeric acid in polyaniline has been demonstrated by atomic force microscopy. The size and morphology of the nanoparticles of the polyaniline–PAMPS complexes depended on the method of the synthesis. A comparison of some physical and chemical properties of water dispersible conducting polyaniline–PAMPS was performed under production by enzymatic and chemical methods. It was found a difference in structures and some physicochemical properties of polyaniline colloids prepared by chemical and laccase‐catalyzed methods. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Cryostructuring of polymer systems. XXX. Poly(vinyl alcohol)‐based composite cryogels filled with small disperse oil droplets: A gel system capable of mechanically induced releasing of the lipophilic constituents
Authors: Podorozhko Elena A. , Korlyukov Alexander A. , Lozinsky Vladimir I. 
Published: March 2010

AbstractComposite heterophase poly(vinyl alcohol) (PVA) cryogels containing entrapped small droplets of Vaseline oil have been prepared and studied. Such oil‐filled cryogels were formed via freeze–thaw treatment of freshly prepared oil‐in‐water emulsions containing varied volume fraction of lipophilic phase, and the influence of the amount of this phase, as well as the effects of freezing conditions on the physicomechanical (shear moduli) and thermal (gel fusion temperature and fusion enthalpy) characteristics of resulting composites have been explored. It was shown that over certain range of PVA concentrations in aqueous phase and a range of volume fraction of the hydrophobic phase its microdroplets performed as “active” fillers causing an increase in both the gel strength and the heat endurance of composites. The light microscopy data on the morphological features of such filled PVA cryogels revealed the effect of diminution in size of oil droplets entrapped in the gel matrix as compared with the initial emulsions. This effect can be explained by the disintegrating action of crushing and shear stresses arising upon the system freezing and growth of ice crystals. The oil‐filled PVA cryogels were found to be capable of gradually releasing the lipophilic constituents (the Rose hips oil, in this case) in response to the cyclic mechanical compression. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Electrochemistry and electrocatalysis with hemoglobin in hollow polyelectrolyte fibrous mats
Authors: Song Min , Jiang Hui , Wang Xuemei , Ge Liqin 
Published: March 2010

AbstractTo form the PS/PAH fibers, positively charged poly(allylamine hydrochloride) (PAH) was coated on the surface of polystyrene (PS) fibers. Then, the ordered Hb‐PS/PAH film was prepared by the self‐assembly of hemoglobin (Hb) on the surface of fibers and characterized by electrochemical and spectroscopic methods. Cyclic voltammetry of the self‐assembled Hb‐PS/PAH films modified on glassy carbon electrode (GCE) displayed a quasi‐reversible electrochemical response in pH 5.0 buffers. Moreover, the Hb‐PS/PAH films also exhibited the electrocatalytic activity to the reduction of H2O2. Consequently, the Hb‐PS/PAH films are favorable for the direct electrochemistry of heme containing proteins, suggesting their potential application as the promising sensitive biosensor. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Novel hydrogels of PVP–CMC and their swelling effect on viscoelastic properties
Authors: Roy Niladri , Saha Nabanita , Kitano Takeshi , Saha Petr 
Published: March 2010

AbstractPolyvinylpyrrolidone (PVP) and carboxymethyl cellulose (CMC) mixed hydrogels were prepared by heat treatment. The physical characteristics of the hydrogels were studied by Fourier transform infrared spectroscopy and scanning electron microscopy. The swelling study of the hydrogels in water shows remarkable water absorption property. The swelling effect on the rheological behavior of PVP‐, PVP–CMC‐, and CMC‐based hydrogels was investigated to judge its application on uneven surface of body. The rheological properties (storage modulus, loss modulus, and complex viscosity) of samples before drying and swelled (15, 30, and 60 min) were measured against angular frequency and composition. The hydrogel containing PVP/CMC ratio of 20 : 80 appeared to be the best hydrogel from rheological and water absorbent points of view. These properties and low cost of the materials utilized in this work suggest that this hydrogel is a viable alternative product for dressing materials. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Surface functionalization of polypropylene nonwovens by metallic deposition
Authors: Tao Dan , Feng Quan , Gao Dawei , Pan Liang , Wei Qufu , Wang Dejuan 
Published: March 2010

AbstractIn this study, melt‐blown polypropylene (PP) nonwovens were used as substrates for the metallic deposition of copper. The substrates were pretreated by O2 plasma, followed by treatments such as sensitization, activation, and reduction. The effects of the copper sulfate concentration, reaction temperature, and plasma power on the conductivity and adhesion strength of the PP nonwovens were investigated after copper deposition. The morphology of the PP nonwovens after copper deposition, analyzed by scanning electron microscopy and atomic force microscopy, revealed that copper nanoclusters were deposited on the fiber surface with a smooth surface morphology and dense structure. X‐ray photoelectron spectroscopy indicated that the copper was present mainly in the form of the elementary substance, which coexisted with a little Cu2+. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010