bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and characterization of chemically modified Jute–Coir hybrid fiber reinforced epoxy novolac composites
Authors: Saw Sudhir Kumar , Sarkhel Gautam , Choudhury Arup 
Published: February 2012

AbstractIn this study, the effects of fiber surface modification and hybrid fiber composition on the properties of the composites is presented. Jute fibers are cellulose rich (>65%) modified by alkali treatment, while the lignin rich (>40%) coconut coir fibers consist in creating quinones by oxidation with sodium chlorite in the lignin portions of fiber and react them with furfuryl alcohol (FA) to create a coating around the fiber more compatible with the epoxy resins used to prepare polymer composites. The maximum improvement on the properties was achieved for the hybrid composite containing the jute–coir content of 50 : 50. The tensile and flexural strength are recorded as 25 and 63 MPa at modified coir fiber content of 50 vol %, respectively, which are 78% and 61% higher than those obtained for unmodified fiber reinforced composites, i.e., tensile and flexural strength are 14 and 39 MPa, respectively. The reinforcement of the modified fiber was significantly enhanced the thermal stability of the composites. SEM features correlated satisfactorily with the mechanical properties of modified fiber reinforced hybrid composites. SEM analysis and water absorption measurements have confirmed the FA‐grafting and shown a better compatibility at the interface between chemically modified fiber bundles and epoxy novolac resin. Hailwood–Horrobin model was used to predict the moisture sorption behavior of the hybrid composite systems. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Small‐scale processing of biomass for biorefinery
Authors: Bruins Marieke E. , Sanders Johan P.M. 
Published: February 2012

AbstractThe current fossil‐based economy is moving towards a more bio‐based economy. To enable this transition, many different processes for biorefinery are being developed. Small‐scale biorefinery processes can be beneficial, not only socially and ecologically, but also economically. The main motivation for small‐scale biorefinery is local re‐use of materials, like water, minerals, organic matter, CO2, and heat. This minimizes costs for recycling and transport. A smart and integrated process design can beat the advantages of economy of scale applied in large‐scale processes. Examples of two fully operational small‐scale systems that produce ethanol and starch are given to illustrate our theory. Specific design rules for small‐scale biorefineries are defined. The focus in design for small‐scale processes should be on minimizing capital costs. Moreover, it is shown that separation of relatively simple pre‐processing at small decentralized and more capital‐intensive processing at large centralized factories, respectively, is advantageous. Integration with a biogas and combined heat and power (CHP) unit will furthermore allow usage of residual material to produce energy needed in the rest of the process. © 2012 Society of Chemical Industry and John Wiley & Sons Ltd
Optimum scale of feedstock processing for renewable diesel production
Authors: Miller Patrick , Sultana Arifa , Kumar Amit 
Published: February 2012

AbstractVegetable oil from canola and camelina can be converted to renewable diesel via hydroprocessing. In this study, a techno‐economic model was developed to estimate the cost of vegetable oil production and the production plant economic optimum size using canola or camelina as feedstock. Minimum, average, and maximum yield cases were considered. If canola and camelina meal can be sold for $0.26/kg, in the average yield case the optimum plant size and minimum cost of oil production is 140 million L/year and $0.63/L for a canola‐press plant, 190 million L/year and $0.55/L for a canola‐solvent plant, 90 million L/year and $0.28/L for a camelina‐press plant, and 120 million L/year and $0.28/L for a camelina‐solvent plant. If camelina meal cannot be sold, the cost of oil from camelina‐press and solvent plants at their optimum sizes is $1.04/L and $0.82/L, respectively. Field cost is the largest cost component and it makes up 75–85% of the total oil production cost. A sensitivity analysis found that field cost and meal price have the greatest effect on oil cost; the optimum size of the plant, on the other hand, is most sensitive to transportation, capital, and operating and maintenance costs. © 2012 Society of Chemical Industry and John Wiley & Sons, Ltd
Catalytic Abatement of Nitrous Oxide Coupled with Functionalization of C1–C3 Alkanes
Authors: Kondratenko V. A. , Hahn T. , Kondratenko E. V. 
Published: February 2012

AbstractMechanistic aspects of selective reduction of N2O by C1–C3 alkanes resulting in N2, olefins, and hydrogen over CaO‐based catalysts were studied by combining catalytic tests at ambient pressure with transient analysis of products in high vacuum with microsecond time resolution. In the frame of this reaction, oxygen species formed from N2O participate in selective (olefin production) and nonselective (COx formation) heterogeneous interactions. The coverage by these species and the interplay of exothermic heterogeneous (N2O decomposition and oxidative alkane conversions) and endothermic homogeneous (thermal nonoxidative dehydrogenation and cracking of hydrocarbons) reaction pathways determine the overall olefin selectivity.
Cyanation of Aryl Bromides with K4[Fe(CN)6] Catalyzed by Dichloro[bis{1‐(dicyclohexylphosphanyl)piperidine}]palladium, a Molecular Source of Nanoparticles, and the Reactions Involved in the Catalyst‐Deactivation Processes
Authors: Gerber Roman , Oberholzer Miriam , Frech Christian M. 
Published: February 2012

AbstractDichloro[bis{1‐(dicyclohexylphosphanyl)piperidine}]palladium [(P{(NC5H10)(C6H11)2})2PdCl2] (1) is a highly active and generally applicable CC cross‐coupling catalyst. Apart from its high catalytic activity in Suzuki, Heck, and Negishi reactions, compound 1 also efficiently converted various electronically activated, nonactivated, and deactivated aryl bromides, which may contain fluoride atoms, trifluoromethane groups, nitriles, acetals, ketones, aldehydes, ethers, esters, amides, as well as heterocyclic aryl bromides, such as pyridines and their derivatives, or thiophenes into their respective aromatic nitriles with K4[Fe(CN)6] as a cyanating agent within 24 h in NMP at 140 °C in the presence of only 0.05 mol % catalyst. Catalyst‐deactivation processes showed that excess cyanide efficiently affected the molecular mechanisms as well as inhibited the catalysis when nanoparticles were involved, owing to the formation of inactive cyanide complexes, such as [Pd(CN)4]2−, [(CN)3Pd(H)]2−, and [(CN)3Pd(Ar)]2−. Thus, the choice of cyanating agent is crucial for the success of the reaction because there is a sharp balance between the rate of cyanide production, efficient product formation, and catalyst poisoning. For example, whereas no product formation was obtained when cyanation reactions were examined with Zn(CN)2 as the cyanating agent, aromatic nitriles were smoothly formed when hexacyanoferrate(II) was used instead. The reason for this striking difference in reactivity was due to the higher stability of hexacyanoferrate(II), which led to a lower rate of cyanide production, and hence, prevented catalyst‐deactivation processes. This pathway was confirmed by the colorimetric detection of cyanides: whereas the conversion of β‐solvato‐α‐cyanocobyrinic acid heptamethyl ester into dicyanocobyrinic acid heptamethyl ester indicated that the cyanide production of Zn(CN)2 proceeded at 25 °C in NMP, reaction temperatures of >100 °C were required for cyanide production with K4[Fe(CN)6]. Mechanistic investigations demonstrate that palladium nanoparticles were the catalytically active form of compound 1.
Lithol Red: A Systematic Structural Study on Salts of a Sulfonated Azo Pigment
Authors: Kennedy Alan R. , Stewart Heather , Eremin Katherine , Stenger Jens 
Published: February 2012

AbstractThe first systematic series of single‐crystal diffraction structures of azo lake pigments is presented (Lithol Red with cations=MgII, CaII, SrII, BaII, NaI and CdII) and includes the only known structures of non‐Ca examples of these pigments. It is shown that these commercially and culturally important species show structural behaviour that can be predicted from a database of structures of related sulfonated azo dyes, a database that was specifically constructed for this purpose. Examples of the successful structural predictions from the prior understanding of the model compounds are that 1) the Mg salt is a solvent‐separated ion pair, whereas the heavier alkaline‐earth elements Ca, Sr and Ba form contact ion pairs, namely, low‐dimensional coordination complexes; 2) all of the Lithol Red anions exist as the hydrazone tautomer and have planar geometries; and 3) the commonly observed packing mode of alternating inorganic layers and organic bilayers is as expected for an ortho‐sulfonated azo species with a planar anion geometry. However, the literature database of dye structures has no predictive use for organic solvate structures, such as that of the observed Na Lithol Red DMF solvate. Interestingly, the Cd salt is isostructural with the Mg salt and not with the Ca salt. It is also observed that linked eight‐membered [MOSO]2 rings are the basic coordination motif for all of the known structures of Ca, Sr and Ba salts of sulfonated azo pigments in which competing carboxylate groups are absent.
Isolation, Structure Determination, and Synthesis of Allo‐RA‐V and Neo‐RA‐V, RA‐Series Bicyclic Peptides from Rubia cordifolia L.
Authors: Hitotsuyanagi Yukio , Odagiri Masumi , Kato Saori , Kusano Jun‐ichi , Hasuda Tomoyo , Fukaya Haruhiko , Takeya Koichi 
Published: February 2012

AbstractTwo bicyclic hexapeptides, allo‐RA‐V (4) and neo‐RA‐V (5), and one cyclic hexapeptide, O‐seco‐RA‐V (6), were isolated from the roots of Rubia cordifolia L. Their gross structures were elucidated on the basis of spectroscopic analysis and X‐ray crystallography of compound 5. The absolute stereochemistry of compounds 4 and 5 were established by their total syntheses, and the absolute stereochemistry of compound 6 by chemical correlation with deoxybouvardin (3). Comparison of the 3D structures of highly active RA‐VII (1) with less‐active compounds 4 and 5 suggests that the orientation of the Tyr‐5 and/or Tyr‐6 phenyl rings plays a significant role in their biological activity. The isolation of peptides 4–6, along with compound 3, and the comparison of their structures seem to indicate that peptide 6 may be the common precursor to bicyclic peptides 3–5 in the plant.
Low‐lying energy isomers and global minima of aqueous nanoclusters: Structures and spectroscopic features of the pentagonal dodecahedron (H2O)20 and (H3O)+(H2O)20
Authors: Xantheas Sotiris S. 
Published: February 2012

AbstractWe rely on a hierarchical approach to identify the low‐lying isomers and corresponding global minima of the pentagonal dodecahedron (H2O)20 and the H3O+(H2O)20 nanoclusters. Initial screening of the isomers is performed using classical interaction potentials, namely the Transferable Interaction 4‐site Potential (TIP4P), the Thole‐Type Flexible Model, versions 2.0 (TTM2‐F) and 2.1 (TTM2.1‐F) for (H2O)20 and the Anisotropic Site Potential (ASP) for H3O+(H2O)20. The nano‐networks obtained with those potentials were subsequently refined at the density functional theory (DFT) with the Becke‐3‐parameter Lee–Yang–Parr (B3LYP) functional and at the second order Møller–Plesset perturbation (MP2) levels of theory. For the pentagonal dodecahedron (H2O)20 it was found that DFT (B3LYP) and MP2 produced the same global minimum. However, this was not the case for the H3O+(H2O)20 cluster, for which MP2 produced a different network for the global minimum when compared to DFT (B3LYP). The low‐lying networks of H3O+(H2O)20 correspond to structures having 9 ‘free’ OH bonds and the hydronium ion on the surface of the nanocluster. The IR spectra of the various networks are further analysed in the OH stretching (‘fingerprint’) region and the various bands are assigned to structural arrangements of the underlying hydrogen bonding network. © 2012 Canadian Society for Chemical Engineering
Disparities in access to care at high‐volume institutions for uro‐oncologic procedures
Authors: Trinh Quoc‐Dien , Sun Maxine , Sammon Jesse , Bianchi Marco , Sukumar Shyam , Ghani Khurshid R. , Jeong Wooju , Dabaja Ali , Shariat Shahrokh F. , Perrotte Paul , Agarwal Piyush K. , Rogers Craig G. , Peabody James O. , Menon Mani , Karakiewicz Pierre I. 
Published: February 2012

AbstractBACKGROUND:Socioeconomic status represents an established barrier to health care access. Age, sex, and race may also play a role. The authors examined whether these affect the access to high‐volume hospitals for uro‐oncologic procedures in the United States.METHODS:Within the Nationwide Inpatient Sample (NIS), the authors focused on radical prostatectomy (RP), radical cystectomy, and nephrectomy (Nx) performed within the 5 most contemporary years (2003‐2007). Logistic regression models were used to estimate the impact of the primary predictors on the likelihood of receiving care at a high‐volume hospital.RESULTS:Between 2003 and 2007, 62,165 RP, 6557 radical cystectomy, and 28,062 Nx cases were recorded within the NIS. Patient age (P = .001), year of surgery (P = .001), Charlson Comorbidity Index (P ≤ .025), median Zip Code income (highest vs lowest quartile, P = .001), and insurance status (private vs Medicare, P = .008) were independent predictors of being treated at high‐volume institutions. Moreover, black race was an independent predictor of decreased utilization of high‐volume institutions for radical cystectomy (P = .012), and female sex was an independent predictor of decreased utilization of high‐volume institutions for Nx (P = .016).CONCLUSIONS:On average, old, sick, poor, and Medicare patients were less likely to be treated at high‐volume hospitals for uro‐oncologic surgery. Similarly, black patients were less likely to have a radical cystectomy at a high‐volume hospital, and female patients were less likely to have an Nx at a high‐volume hospital. Selective referral of individuals who are less likely to receive care at such institutions may represent a health care priority intended to optimize outcomes across all population strata. Cancer 2012. © 2012 American Cancer Society.
Arginase‐1: A novel immunohistochemical marker of hepatocellular differentiation in fine needle aspiration cytology
Authors: McKnight Ryan , Nassar Aziza , Cohen Cynthia , Siddiqui Momin T. 
Published: February 2012

AbstractBACKGROUND:Arginase‐I is a key urea cycle metalloenzyme that has been used as an immunohistochemistry (IHC) marker for hepatocellular carcinoma (HCC). Previous studies have demonstrated the efficacy of HepPar‐1 and glypican‐3 (GPC‐3) IHC in liver fine needle aspiration (FNA) cytology.METHODS:Arginase‐1 IHC was performed on FNA cell blocks, and its performance characteristics were compared with HepPar‐1 and GPC‐3. Ninety‐two formalin‐fixed, paraffin‐embedded cell blocks were selected (HCC [n = 44], cirrhosis [n = 2], focal nodular hyperplasia [n = 3], hepatic adenomas [n = 2], dysplastic nodules [n = 6], and metastatic carcinomas [n = 35]). IHC staining with antibodies directed against arginase‐1, HepPar‐1, and GPC‐3 was performed with appropriate positive and negative controls.RESULTS:Arginase‐1 positivity was demonstrated in 37 of 44 (84.1%) cases of HCC, compared with 32 of 44 cases (72.7%) and 25 of 44 cases (56.8%) for HepPar‐1 and GPC‐3, respectively. Arginase‐1 and GPC‐3 expression were not observed in any cases of metastatic carcinoma (0%), whereas HepPar‐1 expression was present in 1 case of metastatic carcinoma. In addition, both arginase‐1 and HepPar‐1 expression were present in all 13 cases (100%) of nonmalignant hepatocellular lesions, whereas GPC‐3 expression was absent in all 13 cases (0%).CONCLUSION:This study demonstrates that both arginase‐1 and HepPar‐1 are effective IHC markers of hepatocellular differentiation. Furthermore, arginase‐1 demonstrates superior sensitivity compared with GPC‐3 and HepPar‐1 in the diagnosis of HCC, whereas GPC‐3 demonstrates superior specificity, as staining is not observed in benign hepatocellular lesions. Hence, use of arginase‐1 with HepPar‐1 and GPC‐3 can aid in the diagnosis of HCC and separating from metastatic carcinoma. Cancer (Cancer Cytopathol) 2012. © 2012 American Cancer Society.
Fine‐needle aspiration of intrapancreatic accessory spleen: Cytomorphologic features and differential diagnosis
Authors: Tatsas Armanda D. , Owens Christopher L. , Siddiqui Momin T. , Hruban Ralph H. , Ali Syed Z. 
Published: February 2012

AbstractBACKGROUND:Intrapancreatic accessory spleen (IPAS) is a rare benign lesion of the pancreas that frequently clinically and radiographically mimics a solid neoplasm. Very rarely, epidermoid cysts may form in IPAS and be mistaken for a cystic neoplasm of the pancreas on radiographic imaging. IPAS and epidermoid cyst involving intrapancreatic cyst (ECIPAS) are benign, and, if recognized, do not require surgical intervention. There are few reports of the cytopathologic features of IPAS diagnosed by fine‐needle aspiration (FNA).METHODS:Here we report a series of 6 cases of endoscopic ultrasound (EUS)‐guided FNA of IPAS, 3 of which had histological confirmation, including 1 case of histologically confirmed ECIPAS.RESULTS:Cytomorphologic features of IPAS include a polymorphous population of hematopoietic cells, including lymphocytes, eosinophils, histiocytes, plasma cells, and red blood cells, admixed with numerous small blood vessels representing splenic sinusoids. CD8 immunostaining of cell block or core biopsy material highlights splenic endothelial cells and confirms the diagnosis. FNA of ECIPAS reveals predominantly macrophages and proteinaceous debris.CONCLUSIONS:Diagnostic pitfalls include pancreatic neuroendocrine tumor. If IPAS is recognized as a diagnostic consideration on EUS‐FNA, unnecessary surgical resection may be avoided. Cancer (Cancer Cytopathol) 2012. © 2012 American Cancer Society.
The Surface Chemistry of Water on Fe(100): A Density Functional Theory Study
Authors: Govender Ashriti , Curulla Ferré Daniel , Niemantsverdriet J. W. 
Published: February 2012

AbstractThe formation of water by hydrogenation of atomic oxygen is studied using density functional theory. Atomic oxygen preferentially adsorbs at the four‐fold hollow site, the hydroxyl group prefers the bridge site in a tilted configuration, and water is most stable when adsorbed at the top site with the two OH bonds parallel to the Fe surface. Water formation by the hydrogenation of oxygen is a highly activated process on the Fe(100) surface, with similar activation energies, in the order of 1.1 eV, for the first and second hydrogen additions. A more favourable route for the addition of the second hydrogen atom involves the disproportionation of hydroxyl groups to form water and adsorbed oxygen. Dissociation of the OH is also likely since the activation energy is similar to that for disproportionation of 0.65 eV. Furthermore, the results show that the dissociation of water on Fe(100) is a non‐activated process: 0.16 eV for the zero‐coverage limit and 0.03 eV when surface oxygen is present. Herein, adsorption energies, structures and vibrational frequencies are presented for several adsorption states at 0.25 ML coverage, as well as the potential energy surface for water formation on Fe(100).
Structure–Property Relationships in Ionic Liquids: A Study of the Anion Dependence in Vaporization Enthalpies of Imidazolium‐Based Ionic Liquids
Authors: Zaitsau Dzmitry H. , Fumino Koichi , Emel'yanenko Vladimir N. , Yermalayeu Andrei V. , Ludwig Ralf , Verevkin Sergey P. 
Published: February 2012

AbstractVaporization enthalpies for a series of ionic liquids (ILs) with the common cation 1‐ethyl‐3‐methylimidazolium [C2mim] and different counter anions are determined using a quartz crystal microbalance method. Dependences of vaporization enthalpies on physicochemical parameters specific for cation and anion interactions are revealed. A linear relation between enthalpies of vaporization and the intermolecular vibrational frequencies is observed and suggested for calculation of unknown ILs. A simple group‐contribution method is developed for prediction of vaporization enthalpies of alkyl imidazolium‐based ILs.
Application of the Sol–Gel Technique to Develop Synthetic Calcium‐Based Sorbents with Excellent Carbon Dioxide Capture Characteristics
Authors: Broda Marcin , Kierzkowska Agnieszka M. , Müller Christoph R. 
Published: February 2012

AbstractAn option for reducing the release of greenhouse gases into the atmosphere is the implementation of CO2 capture and storage (CCS) technologies. However, the costs associated with capturing CO2 by using the currently available technology of amine scrubbing are very high. An emerging second‐generation CO2 capture technology is the use of calcium‐based sorbents, which exploit the carbonation and calcination reactions of CaO, namely, CaO+CO2↔CaCO3. Naturally occurring Ca‐based sorbents are inexpensive, but show a very rapid decay of CO2 uptake capacity with cycle number. Here, we report the development of synthetic Ca‐based CO2 sorbents using a sol–gel technique. Using this technique, we are able to synthesize a nanostructured material that possesses a high surface area and pore volume and shows excellent CO2 capture characteristics over many cycles. Furthermore, we are able to establish a clear relationship between the structure of the sorbent and its performance. After 30 cycles of calcination and carbonation, the best material possessed a CO2 uptake capacity of 0.51 g of CO2 per gram of sorbent; a value that is about 250 % higher than that for naturally occurring Havelock limestone.
Increased divergence but reduced variation on the Z chromosome relative to autosomes in Ficedula flycatchers: differential introgression or the faster‐Z effect?
Authors: Hogner Silje , Sæther Stein A. , Borge Thomas , Bruvik Torbjørn , Johnsen Arild , Sætre Glenn‐Peter 
Published: February 2012

AbstractRecent multilocus studies of congeneric birds have shown a pattern of elevated interspecific divergence on the Z chromosome compared to the autosomes. In contrast, intraspecifically, birds exhibit less polymorphism on the Z chromosome relative to the autosomes. We show that the four black‐and‐white Ficedula flycatcher species show greater genetic divergence on the Z chromosome than on the autosomes, and that the ratios of intraspecific polymorphism at Z‐linked versus autosomal markers are below the neutral expectation of 75%. In all species pairs, we found more fixed substitutions and fewer shared polymorphisms on the Z chromosome than on the autosomes. Finally, using isolation with migration (IMa) models we estimated gene flow among the four closely related flycatcher species. The results suggest that different pattern of evolution of Z chromosomes and autosomes is best explained by the faster‐Z hypothesis, since the estimated long‐term gene flow parameters were close to zero in all comparisons.