bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prediction of two‐phase flow distribution in parallel pipes using stability analysis
Authors: Pustylnik L. , Barnea D. , Taitel Y. 
Published: August 2006

AbstractTwo‐phase gas liquid flow in pipes is a complex process. One of the problems that is hardly understood is how the two phases are distributed among two or more parallel lines with a common inlet manifold. Steady‐state analysis yields multiple steady‐state solutions. Linear and nonlinear (simulation) stability analyses are performed in order to determine the actual distribution of the flow that will take place in a real system. The analysis shows that when there are four parallel pipes, for example, the two‐phase flow mixture from the common inlet manifold can choose to flow in one, two, three, or in all four pipes, depending on the flow rates of the liquid, and the gas and on the pipes inclination. For low‐flow rates of gas and liquid, the flow tends to take place only in one line, while stagnant liquid columns are present in the other three pipes. As the flow rate increases the flow will take place in 2, 3 and finally in 4 pipes. Experimental data confirm the analysis although matching is only approximate. © 2006 American Institute of Chemical Engineers AIChE J, 2006
Generalized mass‐transfer correction factor for nanofiltration and reverse osmosis
Authors: Geraldes Vítor , Afonso Maria Diná 
Published: August 2006

AbstractThe assessment of the concentration polarization in pressure‐driven membrane modules is fundamental for their design and optimization. To account for the suction effect in nanofiltration (NF)/reverse osmosis (RO) membrane modules, a correction factor for conventional mass‐transfer coefficients at vanishing mass‐transfer rates was obtained through computational fluid dynamics (CFD) simulations of a symmetrical NF/RO rectangular channel with fully developed laminar flow, for a wide range of operating conditions. The correction factor is defined as Ξ = Sh/Sh0, where Sh is the Sherwood number with suction and Sh0 is the Sherwood number for impermeable walls and low mass‐transfer rates. For the range of dimensionless numbers assigned in the simulations, it was found by fitting of CFD data that Ξ depends only on ϕ = Pe/Sh0, through the correlation Ξ = ϕ + (1 + 0.26ϕ1.4)−1.7, where Pe is the permeation Peclet number. This correlation can be used to predict the average concentration polarization index, Γ = R/(Ξ/ϕ − R), where R is the intrinsic rejection, with an average relative error of 3.2%. The correlation obtained appears to be suitable to determine mass‐transfer coefficients at high mass‐transfer rates, independently of the membrane module geometry and the flow regime. Moreover, unlike the correction factor correlations available in the literature, the generalized correlation accurately predicts the concentration polarization index for ϕ < 20. © 2006 American Institute of Chemical Engineers AIChE J, 2006
Evaluation of QT dispersion in β thalassaemia major patients
Authors: Ulger Zulal , Aydinok Yesim , Levent Erturk , Gurses Dolunay , Ozyurek A. Ruhi 
Published: August 2006

AbstractCardiac complications are considered to be the primary cause of death in patients with β thalassaemia major. QT dispersion is a marker variability of ventricular repolarization and is elevated in various high risk groups of patients. This study was carried out in patients with β thalassaemia major to evaluate QT dispersion and to investigate the relationship between QT dispersion and body iron load. Sixty‐two β thalassaemia major patients were enrolled into the study. The average serum ferritin levels and liver iron concentration was assessed. For each patient, QT–QTc intervals and QT–QTc dispersions were calculated and V1S and V5R were measured. All the subjects underwent two‐dimensional M mode echocardiogram and Doppler study. LVMI was found higher in thalassaemia major patients compared to control group. β thalassaemia major patients showed significantly higher mean QT, QTc, QTd, and QTcd values compared to the control group. The mean V5R and V1S amplitudes were also higher in β thalassaemia major patients. There was a positive correlation between LVMI and QTc, QTd and QTcd. However, there was no significant correlation between QT dispersion and serum ferritin and liver iron concentration. Prospective longitudinal studies are needed to assess the prognostic significance of these findings. Am. J. Hematol., 2006. © 2006 Wiley‐Liss, Inc.
First day dynamic changes in antithrombin III activity after supplementation have a predictive value in critically ill patients
Authors: Gando Satoshi , Sawamura Atsushi , Hayakawa Mineji , Hoshino Hirokatsu , Kubota Nobuhiko , Oshiro Akiko 
Published: August 2006

AbstractTo evaluate the changes in the antithrombin III (antithrombin) values after initial supplementation to predict outcome in critically ill patients, we conducted a retrospective study. All consecutive patients admitted to the intensive care unit (ICU) and treated with antithrombin were enrolled in the study. Initial doses of 1,500 IU or 30 IU/kg antithrombin concentrates were administered over an hour. The clinical backgrounds of the patients were collected from computer‐based records. Serial data of antithrombin were collected from the first day of administration (Day 0) to days 1–4. The patients were subdivided into two groups based on whether they demonstrated an increased antithrombin activity of more than 60% on the first day after the initial supplementation (responders) or not (nonresponders). Four hundred thirty‐five patients were enrolled in the present study. Two hundred eighty‐eight patients could achieve an antithrombin activity of more than 60%. The outcome was significantly different between the two groups. A logistic regression analysis revealed the day 1 antithrombin level and an initial increase of less than 60% after supplementation to be independently associated with ICU mortality. We also found a significant increase in the platelet counts and fibrinogen levels, and a decrease in the disseminated intravascular coagulation (DIC) scores for the responders. In conclusion, our findings demonstrated the first‐day dynamic change in antithrombin activity, and not the basal level, to be able to predict critically ill patient death. This dynamic change was associated with an improvement in the platelet counts, fibrinogen levels, and the DIC score. Am. J. Hematol., 2006. © 2006 Wiley‐Liss, Inc.
Role of intra‐arterial steroid administration in the management of steroid‐refractory acute gastrointestinal graft‐versus‐host disease
Authors: Tfayli Arafat , Selby George , Maqbool Feroz , Bierbaum Walter , Hamadani Mehdi 
Published: August 2006

AbstractWe report here a case of severe steroid‐refractory gastrointestinal graft‐versus‐host disease treated with intra‐arterial administration of corticosteroids. A 53‐year‐old female with non‐Hodgkin's lymphoma received peripheral blood hematopoietic stem cell transplant from her HLA‐matched sibling. She developed grade II skin and grade IV gastrointestinal graft‐versus‐host disease with no hepatic involvement. Therapy with oral prednisone easily controlled her skin rash but she had profuse diarrhea that did not respond to high dose intravenous corticosteroids and denileukin diftitox. Infusion of methyl‐prednisolone into superior and inferior mesenteric arteries produced dramatic improvement of diarrhea, with complete resolution of gastrointestinal graft‐versus‐host disease. Am. J. Hematol., 2006, © 2006 Wiley‐Liss, Inc.
A versatile denaturing HPLC approach for human β‐globin gene mutation screening
Authors: Bournazos Stavros N. , Tserga Aggeliki , Patrinos George P. , Papadakis Manoussos N. 
Published: August 2006

AbstractHemoglobinopathies represent the most common genetic disorder worldwide, with a higher prevalence among populations with a history of malaria endemicity. More than 690 mutations in the human β‐globin gene are usually the cause of β‐type hemoglobinopathies. Here, we report a rapid and highly sensitive β‐globin gene mutation screening approach based on denaturing high‐performance liquid chromatography (DHPLC), which contrary to the previously described ones can be used in every HPLC apparatus. The sensitivity and specificity of the method were tested in 120 healthy Greek subjects and 25 β‐thalassemia heterozygotes and homozygotes, in which 11 different β‐globin sequence variations had been previously characterized by denaturing gradient gel electrophoresis. Using this method, we were able to rapidly identify the commonest β‐globin gene mutations, accounting for more than 90% of the mutant β‐globin alleles reported for the Hellenic population. Compared to classical mutation screening approaches, our DHPLC approach provides the means for rapid, highly sensitive, cost‐effective, and semi‐automated simultaneous mutational scanning of a large number of samples. Am. J. Hematol., 2006, © 2006 Wiley‐Liss, Inc.
Limb amputation in hemoglobin SC disease after application of ice and elevation
Authors: Saleem Sadia , Rice Lawrence 
Published: August 2006

AbstractA 31‐year‐old man with hemoglobin SC disease was admitted with acute chest syndrome, treated with antibiotics and ventilator support. His restrained right wrist and hand became swollen and cool, thought due to infiltration of an intravenous line. The hand was elevated, ice packs applied around the clock, and prophylactic low molecular weight heparin given. The arm quickly turned gangrenous. In spite of attempted thrombectomy and red blood cell exchange transfusion, amputation was required. Cold, elevation, and measures that reduce blood flow are known precipitators of sickling and crises. Vasoocclusion of the extremities to the point of gangrene is rarely reported in sickle cell disorders, and this case highlights the dangers of measures limiting blood flow in such patients. Am. J. Hematol., 2006. © 2006 Wiley‐Liss, Inc.
Macrocyclization by Ring‐Closing Metathesis in the Total Synthesis of Natural Products: Reaction Conditions and Limitations
Authors: Gradillas Ana , Pérez‐Castells Javier 
Published: August 2006

AbstractThe construction of macrocycles by ring‐closing metathesis (RCM) is often used as the key step in the synthesis of natural products containing large rings. This reaction is attractive because of its high functional group compatibility and the possibility for further transformations. The finding of suitable reaction conditions is critical for the success of the synthesis. In this Minireview we summarize the efforts of many research groups to develop efficient RCM reactions on their way towards the total synthesis of natural macrocyclic products. Their findings should help in future synthesis to reduce the time‐consuming phase of the optimization of the reaction conditions.
Release of dithiocarbamates into artificial sweat from latex vulcanizates: Effects of the accelerator type and storage time
Authors: Abraham Elizabeth K. , Ramesh P. , Joseph R. 
Published: August 2006

AbstractThe release of commonly used dithiocarbamate accelerators, namely, zinc diethyldithiocarbamate (ZDEC), zinc dibutyldithiocarbamate (ZDBC), zinc dibenzyldithiocarbamate, zinc isobutyldithiocarbamate, and zinc diisononyldithiocarbamate, into artificial sweat from natural rubber latex vulcanizates was studied. The extent of release of ZDEC was much higher than that of ZDBC or other higher homologues, as indicated by high‐performance liquid chromatography analysis. The effect of the storage time on the extent of release of ZDEC into artificial sweat from vulcanizates prepared with various amounts of ZDEC was studied. The result showed that ZDEC migrated significantly to the surface of the vulcanizates upon storage, and the amount that migrated increased with an increase in the shelf time. Moreover, the amount of ZDEC that migrated increased with an increase in the amount of ZDEC added to the latex formulations. The rate of migration, as determined from the slopes of the migration curves, was dependent on the residual ZDEC content, which in turn depended on the initial level of ZDEC incorporated during latex compounding. The analysis of the migration data showed that the migration followed a Fickian behavior, and the diffusion coefficient of ZDEC was slightly dependent on the concentration. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2055–2061, 2006
Melt‐compounded butadiene rubber nanocomposites with improved mechanical properties and abrasion resistance
Authors: Kim Min‐Su , Kim Dong‐Woo , Ray Chowdhury Subhendu , Kim Gue‐Hyun 
Published: August 2006

AbstractHydrophobic polymers such as polyethylene and polypropylene are very difficult to use for preparing nanocomposites without a compatibilizer. However, in this study, polybutadiene rubber (BR; a hydrophobic polymer) nanocomposites were produced successfully without a compatibilizer with a melt‐compounding method. Transmission electron microscopy showed an intercalated and exfoliated clay morphology in the polymer matrix, which led to increased mechanical properties. The tensile and tear strengths of the BR/Cloisite 20A hybrids were 4.4 times and 2 times larger than that of BR, respectively. The rebound resilience, compression set, and abrasion resistance were also improved by the addition of organoclay. The abrasion resistance of BR/Cloisite 20A was approximately 2 times larger than that of BR. The cure time (t90), scorch time (t2), and their difference (t90 − t2) of the BR/organoclay hybrids were much reduced than those of BR. Thus, organoclays behaved as good fillers and effective accelerant agents for BR vulcanization. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2062–2066, 2006
Melting and crystallization behaviors of isotactic polypropylene/acrylonitrile–butadiene rubber blends in the presence and absence of compatibilizers and fillers
Authors: Joseph Aju , George Snoopy , Joseph Kuruvilla , Thomas Sabu 
Published: August 2006

AbstractThe melting and crystallization behaviors of isotactic polypropylene (PP)/acrylonitrile–butadiene rubber (NBR) blends were investigated with differential scanning calorimetry. The samples were scanned at a heating rate of 20°C/min in a nitrogen atmosphere. The effects of blend ratio, compatibilizer, and filler addition on the melting and crystallization characteristics of the blends were analyzed. Analysis showed that blend ratio had a predominant effect on the values of onset of crystallization and crystallization temperature, although the heat of fusion (ΔHf), onset of melting, and melting temperature were unaffected. The presence of compatibilizer in the blend had an appreciable influence on the crystallization behavior. ΔHf, heat of crystallization, and percentage crystallinity of the compatibilized blends were higher than those of the uncompatibilized blends. Fillers had little impact on the melting behavior of the blends. The morphology of the blends were analyzed with scanning electron microscopy. Hot‐stage polarizing optical microscopy was used to study the spherulitic morphology of PP on the addition of NBR. The addition of a few percentage NBR significantly reduced the average spherulite size of PP in the blend followed by a marginal decrease. Blend ratio had a pronounced impact on the growth rate of PP spherulites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2067–2080, 2006
Optimization of the preparation of a poly(aspartic acid) superabsorbent resin with response surface methodology
Authors: Zhao Ying , Fang Li , Tan Tianwei 
Published: August 2006

AbstractA poly(aspartic acid) superabsorbent resin was synthesized with polysuccinimide through chemical crosslinking with a crosslinking agent (diamine). The optimization of its preparation was investigated with response surface methodology. According to the Plackett–Burman design, the crosslinking temperature, drying temperature, and dissolving time of polysuccinimide had significant influences on the swelling ratio of the poly(aspartic acid) resin, which was the criterion for describing the water absorption capacity. Central composite design and response surface analysis were employed subsequently to further optimize the three aforementioned factors. A maximum swelling ratio greater than 500 g/g was attained; this was more than a 60% increase in comparison with previous results. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2616–2622, 2006
Atom transfer radical polymerization of styrene with 2‐(1‐bromoethyl)‐anthraquinone as an initiator
Authors: Zhao Kang , Zhu Xiulin , Cheng Zhenping , Wang Gang , Zhu Jian 
Published: August 2006

Abstract2‐(1‐Bromoethyl)‐anthraquinone (BEAQ) was successfully used as an initiator in the atom transfer radical polymerization of styrene with CuBr/N,N,N′,N′,N″‐pentamethyldiethylenetriamine as the catalyst at 110°C. The polymerizations were well controlled with a linear increase in the molecular weights (Mn's) of the polymers with monomer conversion and relatively low polydispersities (1.1 < weight‐average molecular weight (Mw)/Mn < 1.5) throughout the poly merizations. The resultant polystyrene thus possessed one chromophore moiety (2‐ethyl‐anthraquinone) at the α end and one bromine atom at the ω end, both from the initiator BEAQ. The intensity of UV absorptions of the resultant polymers decreased with increasing molecular weights of the polymers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2081–2085, 2006
Synthesis of conducting water‐soluble polyaniline with iron(III) porphyrin
Authors: Nabid M. R. , Sedghi R. , Jamaat P. R. , Safari N. , Entezami A. A. 
Published: August 2006

AbstractThe porphyrin‐catalyzed, template‐guided polymerization of aniline was carried out in an aqueous buffer solution. Hydrogen peroxide and iron(III) tetrasulfonated tetraphenyl porphyrin catalyzed the polymerization of aniline in the presence of sulfonated polystyrene as a template. The polymerization was carried out at different pHs ranging from 1 to 5. Ultraviolet–visible spectroscopy indicated the formation of a conducting form of polyaniline. The extent of the polymerization increased with decreasing pH of the solution. The maximum absorbance of the polaron band at 750 nm was obtained at pH 2, but when the polymerization was performed with pH 4, this band shifted to a longer wavelength. These results confirmed that a longer chain length of polyaniline was obtained with pH 4. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2929–2934, 2006
Flame retardancy and nondripping properties of ammonium polyphosphate/poly(butylene succinate) composites enhanced by water crosslinking
Authors: Kuan Chen‐Feng , Kuan Hsu‐Chiang , Ma Chen‐Chi M. , Chen Chia‐Hsun 
Published: August 2006

AbstractAmmonium polyphosphate (APP)/poly(butylene succinate) (PBS) composites were prepared with a unique water‐crosslinking technique to improve the flame retardancy and nondripping properties of the composites and to maintain the main structure of the composites during flame tests. The composites were treated with a coupling agent (tetraethoxysilane) and then were compounded in a twin‐screw extruder. The compound was moisture‐crosslinked. Fourier transform infrared spectra were used to monitor the water‐crosslinking reaction. The composites via the water‐crosslinking treatment exhibited improved mechanical properties because of the interfacial bonding between the APP and PBS matrix. Scanning electron microscopy of the fractured surfaces of the water‐crosslinked composites showed that the void size increased with increasing water‐crosslinking time. Composites with 15 wt % APP were classified as UL‐94 V‐2; however, the ones with only a 0.5‐h water‐crosslinking reaction were classified as UL‐94 V‐0. Thermal analyses of the water‐crosslinked composites indicated that the thermal degradation temperature of the composites increased with increasing water‐crosslinking time. Differential scanning calorimetry results revealed that the water‐crosslinking reaction could limit the crystallization rate of PBS. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2935–2945, 2006
Nanocomposite alkyd coatings
Authors: Jiratumnukul Nantana , Pruthipaitoon Sirirat , Pitsaroup Tossaporn 
Published: August 2006

AbstractOrganophilic montmorillonite intercalants were prepared by a cation‐exchange process between Na+ ions of montmorillonite and ammonium salt of octadecylamine. Fourier transform infrared (FTIR) spectrometry and X‐ray diffraction analyses of the compounds were carried out. The layer spacings of both modified and unmodified montmorillonites were calculated with Bragg's law. FTIR and X‐ray profiles showed organophilic characteristics for the modified montmorillonite, the layer spacing of which increased by two orders of magnitude with respect to that of the unmodified montmorillonite. The prepared organoclay was incorporated into an alkyd‐based clear coating, and X‐ray profiles showed an exfoliated structure for the organoclay alkyd coating. The application of the prepared organoclay to alkyd‐based clear coatings showed a significant enhancement of the hardness and impact strength of the coating film compared with those of unmodified montmorillonite equally incorporated into the coating formulations. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2639–2642, 2006
Synthesis and characterization of poly(ϵ‐caprolactone)–poly(L‐lactide) diblock copolymers with an organic amino calcium catalyst
Authors: Piao Longhai , Sun Jingru , Zhong Zhiyuan , Liang Qizhi , Chen Xuesi , Kim Jung‐Hyun , Jing Xiabin 
Published: August 2006

AbstractThe quasiliving characteristics of the ring‐opening polymerization of ϵ‐caprolactone (CL) catalyzed by an organic amino calcium were demonstrated. Taking advantage of this feature, we synthesized a series of poly(ϵ‐caprolactone) (PCL)–poly(L‐lactide) (PLA) diblock copolymers with the sequential addition of the monomers CL and L‐lactide. The block structure was confirmed by 1H‐NMR, 13C‐NMR, and gel permeation chromatography analysis. The crystalline structure of the copolymers was investigated by differential scanning calorimetry and wide‐angle X‐ray diffraction analysis. When the molecular weight of the PLA block was high enough, phase separation took place in the block copolymer to form PCL and PLA domains, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2654–2660, 2006
Effects of modified poly(methacrylic acid) copolymer on rheological properties of ceramic suspension and sintered ceramic strength
Authors: Wang Haihua , Shen Yiding , Fei Guiqiang , Li Ganghui , Zhang Yaping 
Published: August 2006

AbstractModified waterborne poly(methacrylic acid) (MPBMA) with hydrophilic and hydrophobic groups is prepared by reacting maleic anhydride/polyglycol, α‐olefine benzenesulfone, and methyl methacrylate. Using MPBMA as a ceramic dispersant, the effects of the MPBMA concentration on the rheological behavior of a ceramic suspension and the ceramic breaking strength are studied, and the reasons and its dispersing mechanism are analyzed. The results show that MPBMA can improve the suspension's rheological properties and enhance the ceramic strength. The optimum copolymer concentration is 0.20 wt % at pH 9–10. When adding 0.20 wt % MPBMA, the suspension's absolute ζ potential increases from 23.7 to 64.2 mV, and its zero shear viscosity decreases from 714.3 to 73.4 mPa s. At the same time, its thixotropy area reaches the minimum, and the suspension exhibits Newton flow behavior and good dispersivity. Compared with inorganic dispersant, the ceramic with added MPBMA has higher breaking strength, which is increased from 160 to 352 MPa. Scanning electron microscopy photographs show that the flocculate of particles is disintegrated and the particles scatter mutually. They also show that no aggregation phenomenon appears in the ceramic with MPBMA added and the pores distribute uniformly. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2661–2667, 2006