bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanism on The Disproportionating Synthesis of Dichlorodimethyl‐ silane by ZSM‐5(5 T)@γ‐Al2O3 Series Core‐Shell Catalysts
Authors: Xu Wenyuan , Yan Fei , Yang Shaoming , Guo Zanru , Hu Lin , He Zhongyi , Hong Sanguo 
Published: December 2019

AbstractIn view of the wide application of organosilicon bifunctional structure in industry, the most effective disproportionation solution is used by the new catalyst to prepare the largest and the most versatile organic silicon monomer dimethyldichlorosilane. However, there are still remaining doubts on the disproportionation mechanism of the catalyst. The Density Functional Theory (DFT) was used to theoretically calculate the disproportionation mechanism of 5 T clusters ZSM‐5@γ‐Al2O3 series catalysts at the B3LYP/6–311++G(3df, 2pd) level. The properties were verified and the catalytic effects of different active sites pre‐ and post‐ modified by AlCl3 were calculated and compared. The active center of HZSM‐5@γ‐Al2O3 was proton, and that of AlCl3/ZSM‐5@γ‐Al2O3 changed to lewis acidic center. The presence of the lewis acid center enhances the total activity of the catalyst to some extent. The catalytic activity of the 5 T cluster ZSM‐5@γ‐Al2O3 catalyst modified by AlCl3 was higher, which was the same as the experimental results.
Thermal treatment of pyrolytic lignin and polyethylene terephthalate toward carbon fiber production
Authors: Qu Wangda , Bai Xianglan 
Published: December 2019

ABSTRACTIn this work, pyrolytic lignin (PL) was thermally co‐treated with polyethylene terephthalate (PET) to produce carbon fiber precursor. The produced PL‐PET precursors were thoroughly characterized and analyzed, and then being processed into carbon fiber. It was found that a novel precursor, rather than their physical blending, was formed by the thermal co‐treatment, indicating there were strong interactions between PL and PET. The novel PL‐PET precursors had enhanced thermal properties and rheological characteristics, therefore are more suitable for processing into better carbon fibers based on melt‐spinning method. In this study, the precursor fibers derived from the co‐treatment of PL and 5% PET were also stretched under tension during stabilization step to reduce the fiber diameter and improve molecular orientation. The resulting carbon fibers with an average diameter of 12.6 μm had the tensile strength of up to 1220 MPa. This work demonstrated that PET could be used to improve the processability and quality of lignin‐based carbon fiber when it is chemically bonded with lignin‐based precursor. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48843.
Influence of the addition of PEG into PCL‐based waterborne polyurethane‐urea dispersions and films properties
Authors: Vadillo Julen , Larraza Izaskun , Arbelaiz Aitor , Corcuera Maria Angeles , Save Maud , Derail Christophe , Eceiza Arantxa 
Published: December 2019

ABSTRACTIn this work, segmented waterborne polyurethane‐urea (WBPUU) dispersions containing hydrophobic polycaprolactone (PCL) and hydrophilic poly(ethylene glycol) (PEG) in different molar ratios are synthesized and used for the subsequent preparation of films by casting. The molar ratio of PEG is gradually increased up to 0.20 in order to analyze the effect of low hydrophilic PEG content (from 1.7 to 7.1 wt %) on the properties of resulting dispersions and films. Regarding the dispersions, the addition of PEG results in an increase of the particle size, from 86 ± 1 in the case of pure PCL‐based system to 112 ± 15 for systems containing 7.1 wt % of PEG, as well as in the formation of a core–shell structure in the particles. Films show different behaviors depending on their PEG content. WBPUUs containing just PCL or very low content of PEG in the soft segment present higher stiffness. However, the addition of PEG in a content of 3.4 wt % or higher hinder the ability of the short‐range ordering of the hard segment, increasing the elongation at break from 842 ± 102 MPa for PCL‐based WBPUU to 1312 ± 84 MPa for the system with the highest PEG content. Systems with higher PEG content form nanoparticles with more segregated core–shell structures inducing to the film a higher hydrophilicity. Hence, the addition of PEG to a PCL‐based WBPUU allows to tune the properties of the resulting film increasing the range of application of these materials. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48847.
Effect of modified Mg2B2O5w on mechanical and friction properties of oil‐containing monomer casting nylon
Authors: Feng Qi , Wang Fan , Wang Yuxin , Zhang Qian , Wang Yuexin 
Published: December 2019

ABSTRACTThe Mg2B2O5w modified by toluene‐2, 4‐diisocyanate (TDI) and fatty amine (n‐dodecylamine(D) or n‐octadecylamine (O)) was used in oil‐containing monomer casting (OMC) nylon, and the effect of modified Mg2B2O5w on mechanical and friction properties of OMC nylon composites was investigated. The significant improvement of the mechanical and friction properties of composites was observed. The addition of 0.15 wt% TDI‐D‐Mg2B2O5w or TDI‐O‐Mg2B2O5w resulted in 21 and 20% growth in the tensile strength, 53 and 52% increase in the flexural strength, respectively. Additionally, nearly 60 and 58% reduction in the friction coefficient, about 84 and 80% decrease in the abrasion quantity. Furthermore, the worn surface of composites exhibited smooth, which confirmed the antiwear effect of Mg2B2O5w. The improvement was attributed to the interfacial adhesion between whiskers and matrix by hydrogen bonds. This work provided a facile approach to the design of wear‐resistant polymer composites that hold significant potential in construction machinery industry. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48856.
Osteoarthritis from evolutionary and mechanistic perspectives
Authors: Tangredi Basil P. , Lawler Dennis F. 
Published: December 2019

AbstractDevelopmental osteogenesis and the pathologies associated with tissues that normally are mineralized are active areas of research. All of the basic cell types of skeletal tissue evolved in early aquatic vertebrates. Their characteristics, transcription factors, and signaling pathways have been conserved, even as they adapted to the challenge imposed by gravity in the transition to terrestrial existence. The response to excess mechanical stress (among other factors) can be expressed in the pathologic phenotype described as osteoarthritis (OA). OA is mediated by epigenetic modification of the same conserved developmental gene networks, rather than by gene mutations or new chemical signaling pathways. Thus, these responses have their evolutionary roots in morphogenesis. Epigenetic channeling and heterochrony, orchestrated primarily by microRNAs, maintain the sequence of these responses, while allowing variation in their timing that depends at least partly on the life history of the individual.
A delay‐dependent asymptotic stability criteria for uncertain BAM neural networks with leakage and discrete time‐varying delays: A novel summation inequality
Authors: Sowmiya Chandran , Raja Ramachandran , Cao Jinde , Rajchakit Grienggrai , Alsaedi Ahmed 
Published: December 2019

AbstractThis proposed research work aims to investigate the problem of uncertain BAM neural networks with leakage and discrete time‐varying delays in the sense of asymptotic stable by applying convex combination approach, discrete‐time Wirtinger inequality. It is pointed out that a novel summation inequality is entrenched based on discrete type Wirtinger based inequality. By the aid of novel inequality, reciprocally convex combination technique, time‐varying delays are examined to certify the stability of neural networks. Here, the uncertainties are considered as a randomly occurring parameter uncertainties and it conforms certain mutually uncorrelated Bernoulli‐distributed white noise sequences. The important feature of the results reported here is that the probability of occurrence of the parameter uncertainties are known a priori. To demonstrate the theoretical results of this research paper, numerical examples are given to expo the validity and efficiency of our results with the help of LMI Control toolbox in matlab.
Determining the priorities in utilization of forest residues as biomass: an A'wot analysis
Authors: Kurt Rifat 
Published: December 2019

AbstractThe gap between global energy production and consumption is increasing at a fast pace along with population growth, industrialization, and technological developments, resulting in a rapid increase in the need for energy. This has led countries to use their own resources more effectively. Consequently, in addition to existing energy sources, alternative solutions are now being sought for this problem via renewable resources such as biomass energy production. As forest resources are abundantly available in Turkey, forest residues constitute a significant biomass potential. This study aimed to identify key strategic factors in the evaluation of forest residues as biomass using A'WOT analysis. Measurement of the factors in SWOT (Strengths, Weaknesses, Opportunities and Threats) analysis, and their ranking, was enabled by quantification via A'WOT analysis, which is a combination of SWOT analysis and the analytic hierarchy process (AHP). A survey was conducted among relevant experts in Turkey to determine SWOT factors and AHP weights. As a result, eight sub‐factors for strengths and threats, seven sub‐factors for opportunities, and four sub‐factors for weaknesses were determined for analysis. Each SWOT parameter was then quantified by considering the viewpoints of the surveyed experts, and the resulting matrix was used to determine the vector weights and priorities of the groups and factors. The results indicated that if forest residues could be utilized as an alternative energy source, this would more than fill the gap between the production and consumption of energy in the country. In the evaluation of forest residues in Turkey, transportation costs emerged as the weakest factor, while the removal of natural sources of nutrition and fertilizer from the forest cover was seen as the greatest threat. The most important opportunity was perceived to be the improvement of forest management along with energy and climate‐change policies and activities. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.
Quantitative determination of bilobetin in rat plasma by HPLC–MS/MS and its application to a pharmacokinetic study
Authors: Son Heebin , Kang Wonku 
Published: December 2019

AbstractAlthough bilobetin, a biflavone isolated from the leaves of Ginkgo biloba, represents a variety of pharmacological activities, to date there have been no validated determination methods for bilobetin in biological samples. Thus, we developed a liquid chromatographic method using a tandem mass spectrometry for the determination of bilobetin in rat plasma. After protein precipitation with acetonitrile including diclofenac (internal standard), the analytes were chromatographed on a reversed‐phased column with a mobile phase of purified water and acetonitrile (3:7, v/v, including 0.1% formic acid). The ion transitions of the precursor to the product ion were principally deprotonated ions [M − H]− at m/z 551.2 → 519.2 for bilobetin and 296.1 → 251.7 for the IS. The accuracy and precision of the assay were in accordance with US Food and Drug Administration regulations for the validation of bioanalytical methods. This analytical method was successfully applied to monitor plasma concentrations of bilobetin over time following intravenous administration in rats.
Application of the microsoft excel solver tool in the optimization of distillation sequences problems
Authors: Briones Laura , Morales Victoria , Iglesias José , Morales Gabriel , Escola Jose M. 
Published: December 2019

AbstractDistillation is a very important operation for purification and separation in Chemical Engineering field. The determination of the optimal distillation sequence is key to minimize the total investment and operating cost and it can be posed as a mixed integer‐linear programming (MILP) problem. To solve them and due to the high number of variables and equations, it is required the use of specific software, for example, General Algebraic Modeling System or A Mathematical Programming Language. However, these software involve long training for the student to adequately harness them. The use of non‐specialized, widespread and easy to access software programs is a good opportunity to tackle the teaching of some typical optimization problems. One of them is the Microsoft Excel Solver Tool, accessible by any engineering student who usually learn its use in the first years of their degree, so that MS‐Excel is already known when students deal with optimization problems. Additionally, it is scarcely known that Microsoft Excel Solver may tackle both real and binary variables, so it is possible to leverage it for solving MILP problems. This paper presents an example of distillation sequences problem aimed to separate a mixture comprising four different compounds with a minimal operational cost (which constitutes a MILP optimization problem indeed) solved using Excel Solver tool. This methodology was taught successfully to the students of the Master of Chemical Engineering of Rey Juan Carlos University and Autónoma University of Madrid.
An exploratory investigation of shopper behaviour in an immersive virtual reality store
Authors: Schnack Alexander , Wright Malcolm J. , Holdershaw Judith L. 
Published: December 2019

AbstractShopper research has long been undertaken with physical simulated stores and desktop‐operated virtual stores. However, recent developments in motion‐tracked virtual reality offer a range of new possibilities for research using immersive walk‐around virtual simulated stores. To date, there is little knowledge published on the authenticity of shopper behaviour in such immersive virtual environments. The present study therefore reports exploratory results from 153 multicategory shopping trips conducted in an immersive virtual convenience store. Observed shopper metrics and theoretical effects are compared with equivalent data obtained from published sources and found to be consistent across all measures. Specifically, shoppers purchase a plausible share of private label brands, more private label brands in lower consumption pleasure product categories, more products from higher compared with lower shelf positions, make a plausible proportion of impulsive purchases, and spend less time inspecting familiar versus unfamiliar brands. Further, time in‐store, total spending, and product handling time are higher for women than for men. These exploratory findings show that participants continue to exhibit realistic shopper behaviours in an immersive virtual simulated store. Such stores are therefore a cost‐effective alternative to other methods for measuring consumer behaviour. They offer significant potential for innovative experimental designs in consumer research, as well as potential for future use as a digital shopping channel.
Torque device suture technique to achieve hemostasis in large‐bore venous access
Authors: Karahalios Brian , Rojas Stephanie F. , Singh Rahul , Cavazos Miguel C. , Chinnadurai Ponraj , Huie Lin C. 
Published: December 2019

AbstractObjectivesTo describe and compare a novel technique using a torque device to manage figure‐of‐eight suture tension for venous access hemostasis in patients who have undergone atrial septal defect (ASD) or patent foramen ovale (PFO) closure.BackgroundLarge bore venous access has become increasingly important in transcatheter procedures, but management of hemostasis can be time‐consuming and/or resource intensive. As such, various techniques have sought to provide cost effective and safe alternatives to manual compression. We describe a modification of the figure‐of‐eight suture technique wherein we apply a torque device to manage variable suture tension instead of tying a knot and compare it to the standard figure‐of‐eight suture technique.MethodsWe performed a retrospective study of 40 consecutive patients who underwent ASD or PFO closure, 20 of whom underwent standard figure‐of‐eight technique and 20 of whom underwent figure‐of‐eight with torque device modification. Bleeding Academic Research Consortium definitions were used to categorize bleeding events.ResultsThe groups were similar in age, gender, weight, aspirin use, platelet count, procedure time, hemoglobin, and international normalized ratio. Standard figure‐of‐eight suture had seven patients with bleeding, with six classified as BARC II and one as BARC I. Figure‐of‐eight plus torque device had three patients with bleeding, with two classified BARC II and one as BARC I. There were no incidences of hematoma in either group.ConclusionThe torque device suture technique is a unique modification of the figure‐of‐eight suture technique to achieve venous hemostasis. In addition, the modification allows secure and variable suture tension as well as easy removal by nursing staff.
Stereochemistry of the Reaction Intermediates of Prolinol Ether Catalyzed Reactions Characterized by Vibrational Circular Dichroism Spectroscopy
Authors: Golub Tino P. , Merten Christian 
Published: December 2019

AbstractSpectroscopic characterizations of key reaction intermediates are often considered the final confirmation of a reaction mechanism. This proof‐of‐principle study showcases the application of vibrational circular dichroism (VCD) spectroscopy for the characterization of in situ generated reaction intermediates using the key intermediates of enamine catalysis of Jørgensen–Hayashi‐type prolinol ether catalysts as model system. By comparison of experimental and computed spectra, the enamines are shown to preferentially adopt an anti‐conformation with E‐configured C=C bond. For the parent prolinol catalyst, the structure and stereochemistry of the oxazolidine side product is determined as well. This study thus demonstrates that VCD spectra can provide insights into structural preferences of organocatalysts that utilize a covalent activation mechanism. Thereby it outlines new fields of applications for VCD spectroscopy and finally adds the technique to the toolbox of physical organic chemistry for in‐depth mechanistic studies.
Influence of Surface Roughness on Pressure Drop in Two‐Phase Flow of Saturated Hydrocarbons
Authors: Fries Simon , Deeb Mohammad , Luke Andrea 
Published: December 2019

AbstractPressure drop of propane and propylene in gas‐liquid saturation state are investigated for copper and mild steel test tubes. The surface structure of both tubes is determined with the focus variation method, yielding a six times higher roughness for the steel tube, although both tubes are manufactured in the same manner. In both tubes single phase pressure drop validation measurements are carried out and compared to known correlations. For two‐phase investigations both fluids are investigated at the reduced saturation pressure for three different mass fluxes. The vapor quality is varied.
Retrospective cohort analysis of heart rate variability in patients with high altitude pulmonary hypertension in Tibet
Authors: Qian Zhang , Fan Aili , Dawa  , Dawaciren  , Pan Binbin 
Published: December 2019

AbstractBackgroundStudies from both humans and animals experiments have offered abundant evidence supporting that mountain sickness is associated with changes in autonomic nervous function (ANF), which can be measured by heart rate variability (HRV).HypothesisWe aimed to assess changes of ANF in chronic mountain disease by measuring HRV in patients with high altitude pulmonary hypertension (HAPH).MethodsFrom November 2018 to March 2019, 120 patients in the cardiac care unit of the People's Hospital of Tibet Autonomous Region were selected as the observation group, and 50 patients without organic heart disease served as the control group. Pulmonary artery systolic pressure was evaluated by echocardiography in patients with HAPH, divided into three groups: mild (30‐49 mm Hg), moderate (50‐69 mm Hg) and severity (≥70 mm Hg) groups. A 24‐hour dynamic electrocardiogram (DCG) was obtained for each patient. HRV (SDNN, SDANN, RMSSD, PNN50, and HRVTI for time domain; TP, VLF, LF, HF, and LF/HF for frequency domain) indexes were measured and compared.ResultsCompared with the control group, time domain parameters including SDNN, SDANN, RMSSD, PNN50, and HRVTI were reduced, as well as frequency domain indexes such as TP, VLF, LF, and HF. LF/HF was highest in mild HAPH group and lowest in the moderate HAPH group, and the difference between the two groups was statistically significant.ConclusionsThe HRV of patients with chronic HAPH in high altitude areas in Tibet is significantly reduced relative to healthy controls, and significantly negatively correlated with the severity of pulmonary artery hypertension.
Performance analysis of ACO‐based improved virtual machine allocation in cloud for IoT‐enabled healthcare
Authors: Kavitha Kadarla , Sharma S.C. 
Published: December 2019

SummaryThe Internet of Things (IoT)–enabled healthcare environment irregularly requires the resources from the Cloud to handle massive amounts of data, which impacts the response times of the Cloud. A typical healthcare application scenario could be to monitor the heart‐patients who require the highest response times, immediate attention of all the stakeholders, and very quick decisions. This paper replaces the default First‐Come‐First‐Serve (FCFS) Virtual Machine (VM) allocation scheme of the Cloud computing in CloudSim with the implementation of Ant Colony Optimization (ACO) by the efficient tuning of parameters. An IoT‐enabled healthcare environment is designed, which irregularly requires the resources from the Cloud to handle massive amounts of data to assess the impact of the response times of the Cloud. Several experiments have been carried out to assess the optimal VM allocation using ACO by varying different parameters like the variation of the number of ants, the strength of pheromone, the number of VMs, the number of hosts, the strength of computing power of processing elements, the number of users, and the size of the workloads. Experimental results indicate that the ACO optimally utilizes the resources in a Cloud when compared to the default FCFS strategy. The results indicate that on an average, the ACO gives 25% to 30% improved response times than FCFS in the given healthcare and Cloud scenarios.
Social impact bonds: The evolution of research and a review of the academic literature
Authors: Broccardo Eleonora , Mazzuca Maria , Frigotto Maria Laura 
Published: December 2019

AbstractThis study reviews all the academic contributions to research on social impact bonds (SIBs). It responds to the need for clarification across and within the various perspectives used in the literature. The goal was to assess the approaches used in extant studies and to offer directions for future studies. A bibliometric analysis was performed, and a framework was developed in which the contributions were positioned according to two criteria: (a) a distinction on the basis of research approaches and perspectives on SIBs and (b) an analysis of content according to a protocol that includes key questions corresponding with the most pressing issues in this area.