bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of Swift Heavy Ions and Gamma Radiation upon Optical, Structural, and Chemical Properties of Polypropylene Polymer Films
Authors: Gupta Sanjeev Kumar , Singh Paramjit , Singh Rajinder , Kumar Rajesh 
Published: March 2015

ABSTRACTThe present work focuses on the effects of two different ions (70 MeV carbon and 50 MeV lithium) and gamma radiation upon the structural, optical, and chemical properties of 125‐μm thick polypropylene (PP) polymer films. The different samples of PP were irradiated with ions to the fluences in the range 1011–1013 ions/cm2 and exposed to gamma radiation of doses in the range 100–1250 kGy. A comparative study is carried out upon different parameters of irradiated polymer samples such as crystallite size and band gap energy. The structural properties are effectively modified by the ions irradiation, whereas gamma exposure shows insignificant changes in this regard; however, gamma exposure is observed to be effective in gradually decreasing the band gap energy of the PP samples with an increase in the gamma dose. The formation of new chemical bands is observed in the ion‐irradiated and gamma‐exposed PP polymer samples.
Predicting euarchontan body mass: A comparison of tarsal and dental variables
Authors: Yapuncich Gabriel S. , Gladman Justin T. , Boyer Doug M. 
Published: March 2015

ABSTRACTObjective: Multiple meaningful ecological characterizations of a species revolve around body mass. Because body mass cannot be directly measured in extinct taxa, reliable body mass predictors are needed. Many published body mass prediction equations rely on dental dimensions, but certain skeletal dimensions may have a more direct and consistent relationship with body mass. We seek to evaluate the reliability of prediction equations for inferring euarchontan body mass based on measurements of the articular facet areas of the astragalus and calcaneus. Methods: Surface areas of five astragalar facets (n = 217 specimens) and two calcaneal facets (n = 163) were measured. Separate ordinary least squares and multiple regression equations are presented for different levels of taxonomic inclusivity, and the reliability of each equation is evaluated with the coefficient of determination, standard error of the estimate, mean prediction error, and the prediction sum of squares statistic. We compare prediction errors to published prediction equations that utilize dental and/or tarsal measures. Finally, we examine the effects of taxonomically specific regressions and apply our equations to a diverse set of non‐primates. Results: Our results reveal that predictions based on facet areas are more reliable than most linear dental or tarsal predictors. Multivariate approaches are often better than univariate methods, but require more information (making them less useful for fragmentary fossils). While some taxonomically specific regressions improve predictive ability, this is not true for all primate groups. Conclusions: Among individual facets, the ectal and fibular facets of the astragalus and the calcaneal cuboid facet are the best body mass predictors. Since these facets have primarily concave curvature and scale with positive allometry relative to body mass, it appears that candidate skeletal proxies for body mass can be identified based on their curvature and scaling coefficients. Am J Phys Anthropol 157:472–506, 2015. © 2015 Wiley Periodicals, Inc.
Technical note: A linear model for predicting δ13Cprotein
Authors: Pestle William J. , Hubbe Mark , Smith Erin K. , Stevenson Joseph M. 
Published: March 2015

ABSTRACTObjective: Development of a model for the prediction of δ13Cprotein from δ13Ccollagen and Δ13Cap‐co. Model‐generated values could, in turn, serve as “consumer” inputs for multisource mixture modeling of paleodiet. Methods: Linear regression analysis of previously published controlled diet data facilitated the development of a mathematical model for predicting δ13Cprotein (and an experimentally generated error term) from isotopic data routinely generated during the analysis of osseous remains (δ13Cco and Δ13Cap‐co). Results: Regression analysis resulted in a two‐term linear model (δ13Cprotein (%) = (0.78 × δ13Cco) − (0.58× Δ13Cap‐co) − 4.7), possessing a high R‐value of 0.93 (r2 = 0.86, P < 0.01), and experimentally generated error terms of ±1.9% for any predicted individual value of δ13Cprotein. This model was tested using isotopic data from Formative Period individuals from northern Chile's Atacama Desert. Conclusions: The model presented here appears to hold significant potential for the prediction of the carbon isotope signature of dietary protein using only such data as is routinely generated in the course of stable isotope analysis of human osseous remains. These predicted values are ideal for use in multisource mixture modeling of dietary protein source contribution. Am J Phys Anthropol 157:694–703, 2015. © 2015 Wiley Periodicals, Inc.
Quantum bottlenecks and unidirectional energy flow in molecules
Authors: Leitner David M. , Pandey Hari Datt 
Published: March 2015

Quantum mechanical effects can enable energy to flow more efficiently in one direction along a molecule than in others. Ultrafast spectroscopic experiments on substituted benzenes [J. Phys. Chem. B 117, 10898 (2013)] reveal such an asymmetry in the flow of vibrational energy between the two chemical groups of the molecule, i.e., between the phenyl and the substituent. We examine theoretically energy flow in toluene, one of the substituted benzenes probed in the recent experiments, and show that quantum mechanical bottlenecks give rise to a preferred direction of energy flow in this molecule.
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Ein Pyren‐fusioniertes N‐Heteroacen mit elf linear anellierten aromatischen Ringen
Authors: Kohl Bernd , Rominger Frank , Mastalerz Michael 
Published: March 2015

AbstractEin sehr gut lösliches Pyren‐fusioniertes Undecacen wurde durch Anbringung endständiger Triptycenylen‐Einheiten an das lineare aromatische π‐System realisiert. Neben der guten Löslichkeit zeigt die Verbindung eine hohe Kristallisationsneigung. Zwei Polymorphe aus Dichlorbenzol und Chloroform werden beschrieben. In dem Polymorph aus Chloroform zeigt die Hälfte der Moleküle eine ausgeprägte Krümmung aus der π‐Ebene von 26.4°.
Creep characterization of vapor‐grown carbon nanofiber/vinyl ester nanocomposites using a response surface methodology
Authors: Drake Daniel A. , Sullivan Rani W. , Lacy Thomas E. , Pittman Charles U. , Toghiani Hossein , DuBien Janice L. , Nouranian Sasan , Simsiriwong Jutima 
Published: March 2015

ABSTRACTThe effects of selected factors such as vapor‐grown carbon nanofiber (VGCNF) weight fraction, applied stress, and temperature on the viscoelastic responses (creep strain and creep compliance) of VGCNF/vinyl ester (VE) nanocomposites were studied using a central composite design (CCD). Nanocomposite test articles were fabricated by high‐shear mixing, casting, curing, and post curing in an open‐face mold under a nitrogen environment. Short‐term creep/creep recovery experiments were conducted at prescribed combinations of temperature (23.8–69.2°C), applied stress (30.2–49.8 MPa), and VGCNF weight fraction (0.00–1.00 parts of VGCNF per hundred parts of resin) determined from the CCD. Response surface models (RSMs) for predicting these viscoelastic responses were developed using the least squares method and an analysis of variance procedure. The response surface estimates indicate that increasing the VGCNF weight fraction marginally increases the creep resistance of the VGCNF/VE nanocomposite at low temperatures (i.e., 23.8–46.5°C). However, increasing the VGCNF weight fraction decreased the creep resistance of these nanocomposites for temperatures greater than 50°C. The latter response may be due to a decrease in the nanofiber‐to‐matrix adhesion as the temperature is increased. The RSMs for creep strain and creep compliance revealed the interactions between the VGCNF weight fraction, stress, and temperature on the creep behavior of thermoset polymer nanocomposites. The design of experiments approach is useful in revealing interactions between selected factors, and thus can facilitate the development of more physics‐based models. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42162.
Film blowing of PHBV blends and PHBV‐based multilayers for the production of biodegradable packages
Authors: Cunha Mara , Fernandes Bruno , Covas José A. , Vicente António A. , Hilliou Loïc 
Published: March 2015

ABSTRACTPoly(hydroxy butyrate‐co‐valerate) (PHBV) is a biodegradable polymer that is difficult to melt process into films. Such difficulty is mirrored in the lack of literature on film blowing of PHBV‐ or PHBV‐based materials. To circumvent this problem, 70/30 wt % blends of PHBV with a biodegradable compound (PBSebT), or with poly(butylene adipate‐co‐terephtalate) (PBAT), were prepared and tested for extrusion film blowing. Both blends showed a similar rheological pattern at 175°C, which is the maximum processing temperature with tolerable thermal degradation. Blending stabilized the film bubbles, thus widening the processing window. However, film properties such as tensile modulus, strain at break and tear resistance remained isotropic and crystallinity characteristics in the machine and transverse directions were generally similar. To bypass the thermal degradation associated with polymer blending, PHBV/PBAT films were coextruded. These showed enhanced functional properties when compared with films blown from blends. The mechanical properties of bilayered films matched those of films blown from commercial PBAT designed for food packaging. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42165.
Changes in hydrogen bonding in protein plasticized with triethylene glycol
Authors: Hicks Talia Maree , Verbeek Casparus Johannes Reinhard , Lay Mark Christopher , Manley‐Harris Merilyn 
Published: March 2015

ABSTRACTBloodmeal decolored with 4 wt % peracetic acid can be extruded into a semi‐transparent bio‐plastic through the addition of sodium dodecyl sulfate (SDS), water, and triethylene glycol (TEG). TEG is often used to plasticize protein thermoplastic materials because of its ability to form both hydrophobic and hydrogen bonds. Synchrotron‐based FT‐IR was used to monitor changes in the types of hydrogen bonding occurring in TEG plasticized protein during heating. Heating was found to overcome a portion of the weaker hydrogen bonds found within and between proteins, observed as a blue‐shift in the N‐H and O‐H stretching vibrations occurring at ∼3280 cm−1. TEG was shown to be involved in a larger array of hydrogen bonding environments after heating, evidenced by the broadening of the C‐OH stretch around 1076 cm−1, suggesting improved plasticizer‐protein interactions. Additionally, these bonds were found to be as strong as the original interactions, observed as a shift in the C‐OH peak back to its original wavenumber (∼1076 cm−1) during cooling. Initially, TEG was spatially distributed into distinct plasticizer‐rich and plasticizer‐poor domains, giving rise to two glass transitions. Heating allowed the migration and uniform dispersion of TEG throughout the material, and merged the two glass transitions into one broader glass transition region. Heating during DSC removed the peak around 60°C corresponding to the enthalpy of relaxation, which is associated with physical aging of amorphous and semi‐crystalline polymers. While physical aging occurred during the storage of DBM, in the presence of TEG it occurred to a lesser extent. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42166.
Polyethylene battery separator with auto‐shutdown ability, thermal stability of 220°C, and hydrophilic surface via solid‐state ultraviolet irradiation
Authors: Gao Xiang , Sheng Wei , Wang Yongchang , Lin Yegang , Luo Yingwu , Li Bo‐Geng 
Published: March 2015

ABSTRACTTo assure the safety of the lithium‐ion battery, the separator is required to have good thermal stability. Because the single‐layer polyethylene (PE) separator can only tolerate a temperature of 130°C, it is seldom employed currently by lithium‐ion battery manufacturers although its cost is low. In this article, we modified PE separator chain structure through solid‐state ultraviolet (UV) irradiation method to achieve a separator with composite structure of ∼40% crystallized PE and ∼70% gel content. Approximately 40% crystallized PE chains fulfill the task of auto‐shutdown at 130°C through melting and filling the pores. At the same time, the PE separator can maintain integrity till 220°C because of its highly cross‐linked chain structure. Besides, the modified PE separator is hydrophilic with a water contact angle of 33° after UV treatment and is able to absorb more electrolyte. However, the tensile strength and elongation at the break decreased because the cross‐linking network increased the rigidity. Nevertheless, these values still meet the requirements as the separator for lithium‐ion battery. Considering the low cost and easy preparation, current cross‐linked PE separator has potential to be used in lithium‐ion batteries for various applications, including electric vehicles and energy storage purpose. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42169.
Significance of polymer on emulsion stability in surfactant‐polymer flooding
Authors: Xuan Yinglong , Ma Desheng , Zhou Minghui , Gao Ming 
Published: March 2015

ABSTRACTThe influence of polymer on stability and shear rate on droplet size of emulsion is evaluated in the laboratory, microstructure of the emulsion is observed under a microscope, and the pore distribution of the cores is analyzed through mercury injection experiments. In the process of surfactant‐polymer (SP) flooding, the thickness of polymer absorbed on the surface of the rock is calculated by a mathematical model. The experiments show that the polymer is good for the stability of emulsion, with the increase of shear rate, stability becomes better, and droplet size gets smaller. Due to the adsorption of polymer, the pore throat turns narrow, seepage velocity is increasing, and also the emulsion becomes more stable with the smaller‐size droplets. During the single emulsifier flooding, the emulsion is easy to coalescence for its instability, and the seepage channel can be easily blocked, which leads to the high injection pressure. Consequently, the polymer plays an important role on emulsion stability in SP flooding. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42171.
Depolymerization of renewable resources—lignin by sodium hydroxide as a catalyst and its applications to epoxy resin
Authors: Chen Hong‐Zhuo , Li Zhi‐Ying , Liu Xin‐Yu , Tian Yu‐Mei , Yang Liu , Wang Zi‐Chen 
Published: March 2015

ABSTRACTAlkali lignin was successfully depolymerized into polyols with high hydroxyl number via direct hydrolysis using sodium hydroxide (NaOH) as a catalyst, without any organic solvent agent. Hydrolysis of lignin can produce a multitude of high‐value products via alkali‐catalyzed cleavage. This process usually gives good results with respect to the yield of phenols. Through this method, the numbers of the hydroxymethyl and phenolic hydroxyl groups of lignin had been dramatically increased, reaching 2.11%, nearly four times higher than that in the original one. Meanwhile, we added the same amounts (20 wt %) of different depolymerization of lignin (DL) into epoxy resin (EP), and the results showed that DL could not only increase the decomposition temperature of EP, but also remarkably improve its mechanical properties. The optimum reaction time was 1.5 h, the reaction temperature was 250°C, and the optimum sodium hydroxide concentration was 15 wt % for depolymerizing lignin. The mechanical and thermal properties of cured lignin‐based epoxy resin (LEP) were compared with cured neat EP. The cured DL‐based epoxy resin (DLEP) showed the highest adhesive shear strength up to 2.66 MPa, which displayed 122% of the adhesive shear strength of EP. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42176.
Fabrication of pH‐sensitive poly(2‐(diethylamino)ethyl methacrylate)/palygorskite composite microspheres via Pickering emulsion polymerization and their release behavior
Authors: Lu Jia , Wu Jie , Chen Jing , Jin Yeling , Hu Tao , Walters Keisha B. , Ding Shijie 
Published: March 2015

ABSTRACTThe poly(2‐(diethylamino)ethyl methacrylate)/palygorskite (PDEAEMA/PAL) composite microspheres were prepared via Pickering emulsion polymerization using palygorskite (PAL) as an emulsifier. The morphology, chemical structure, and content of PDEAEMA/PAL composite microspheres were investigated by polarizing optical microscopy, scanning electron microscopy (SEM), Fourier‐transform infrared (FT‐IR) spectroscopy, and thermal gravimetric analysis (TGA). The pH‐responsive behavior of composite microspheres was studied by measuring their size at different pH values. Furthermore, their release behavior was investigated using rhodamine B (RhB) as a model molecule. It was proven that the release properties of RhB from PDEAEMA/PAL composite microspheres could be controlled by adjusting the pH values. The study of release kinetics found that Higuchi model was fit for RhB release from PDEAEMA/PAL composite microspheres at pH 5.0, 7.4, and 10.0. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42179.
Actuator and Sensor Fault Reconstructions for Uncertain Lipschitz Nonlinear Systems Based onH∞Observers
Authors: Li Xiaohang , Zhu Fanglai , Xu Liyun 
Published: March 2015

AbstractThis paper considers fault reconstruction problems for a class of uncertain Lipschitz nonlinear systems with actuator faults, sensor faults, and external disturbances. First, by extending the state vector, the original system is transformed into an augmented descriptor system before anobserver, which can decouple the disturbances, is developed. Since the sensor faults become parts of the extended state vector, the descriptor observer can provide not only state estimates but also the sensor fault reconstructions. Second, a second‐order high‐gain sliding mode observer is used to estimate the derivatives of the system outputs in a finite time. Third, using the estimates of the states and the output derivatives, an algebraic actuator fault reconstruction method is proposed. Finally, a simulation example is given to validate the proposed method.
Molecular cloning and transgenic characterization of the genes encoding chalcone synthase and chalcone isomerase from the Tibetan herbal plant Mirabilis himalaica
Authors: Lan Xiaozhong , Quan Hong , Xia Xinli , Yin Weilun , Zheng Weilie 
Published: March 2015

AbstractMirabilis himalaica is an endangered medicinal plant species in the Tibetan Plateau. The two genes respectively encoding chalcone synthase (MhCHS) and chalcone isomerase (MhCHI) were isolated and characterized from M. himalaica. The sequence analysis revealed that the two genes were similar with their corresponding homologous genes in other plants. The tissue profiles showed that both MhCHS and MhCHI had higher expression levels in roots than in stems and leaves. Transgenic hairy root cultures respectively with overexpressing MhCHS and MhCHI were established. The genomic PCR detection confirmed the authority of transgenic hairy root lines, in which either MhCHS or MhCHI expression levels were much higher than that in non‐transgenic hairy root line. Finally, the HPLC detection results demonstrated that the rotenoid contents in MhCHS/MhCHI‐transformed hairy root lines were enhanced. This study provided two candidate genes that could be used to genetic engineering rotenoid biosynthesis in M. himalaica and an alternative method to produce rotenoid using transgenic hairy root cultures.
In silico analysis of human Toll‐like receptor 7 ligand binding domain
Authors: Gupta Chhedi Lal , Akhtar Salman , Sayyed Uzma , Pathak Neelam , Bajpai Preeti 
Published: March 2015

AbstractToll‐like receptors recognizing pathogen‐associated molecular patterns are preface actors for innate immunity. Among them TLR7 is a transmembrane protein playing very crucial role in the signaling pathways involved in innate immunity by recognizing viral ssRNA and specific small molecule agonists. The unavailability of experimental 3D structure of this receptor till date hampers the focused exploration of TLR7 interaction with its ligands. However, several proteins possessing high homology domain enabled us to construct a reliable 3D model of hTLR7 ECD, which was employed to generate the homodimer model using protein–protein docking strategy. Further molecular docking studies between developed homodimer model and ligands were performed to explore the most preferred site of hTLR7 ECD interacting with ligands. The comparative analysis of docking energies and protein–ligand interactions of all the ligands revealed resiquimod as the prominent agonist. Furthermore, molecular interactions between protein–ligand complexes suggested LRR15 and LRR16 region of hTLR7 ECD as the most preferential site for ligand binding. The Ser434 and Gly437 of LRR15 region of hTLR7 were found to be conserved with Drosophila Toll protein. The obtained complex model may lead to a better understanding of TLR7 functioning along with its inheritance from invertebrates to mammals.
Optimization of medium components and physicochemical parameters to simultaneously enhance microbial growth and production of lypolitic enzymes by Stenotrophomonas sp.
Authors: Mazzucotelli Cintia Anabela , Agüero María Victoria , del Rosario Moreira María , Ansorena María Roberta 
Published: March 2015

AbstractThe optimization of lipase and esterase production (LP and EP) and bacterial growth (BG) of a Stenotrophomonas sp. strain was developed. For this purpose, the effect of five different medium components and three physicochemical parameters were evaluated using a Plackett–Burman statistical design. Among eight variables, stirring speed, pH, and peptone concentration were found to be the most effective factors on the three responses under evaluation. An optimization study applying Box–Behnken response surface methodology was used to study the interactive effects of the three selected variables on LP/EP and microorganism growth. Predicted models were found to be significant with high regression coefficients (90%–99%). By using the desirability function approach, the optimum condition applying simultaneous optimization of the three responses under study resulted to be: stirring speed of 100 rpm, pH of 7.5, and a peptone concentration of 10 g/L, with a desirability value of 0.977. Under these optimal conditions, it is possible to achieve in the optimized medium a 15‐fold increase in esterase productivity, a 117‐fold increase in lipase production, and a 9‐log CFU/mL increase in BG, compared with the basal medium without agitation.