bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reactivity of a benzylic lignin-carbohydrate model compound during enzymatic dehydrogenative polymerisation of coniferyl alcohol
Authors: Shimizu Kimiaki , Matsushita Yasuyuki , Aoki Dan , Mitsuda Hayato , Fukushima Kazuhiko 
Published: February 2021

Abstract
Lignin is thought to be covalently bound to carbohydrates like hemicellulose during biosynthesis to form a lignin-carbohydrate complex (LCC). However, successive polymerisation with monolignols after the formation of LCC has not yet been clarified. To investigate the reaction of LCC, its enzymatic dehydrogenative polymerisation was conducted using deuterium-labelled coniferyl alcohol and model compounds, i.e., a lignin model (β-O-4 dimer model) compound (LM) and an LCC model (benzyl ether type) compound (LCCM). The obtained polymers (DHPs) were methylated and subjected to thioacidolysis, and the degradation products were quantified by gas chromatography-mass spectrometry (GC-MS). The results showed that the amount of coniferyl alcohol connected to the LCCM via β-O-4 binding was almost the same as that bound to the LM. However, the amount of unreacted LCCM was larger than that of LM, suggesting that the LCCM is less likely to form condensed structures, i.e., 5-5, β-5, and 4-O-5 structures. This could be due to the steric hindrance of the carbohydrate at the benzylic position.
COVID-19 and pregnancy: are they friends or enemies?
Authors: Gulic Tamara , Blagojevic Zagorac Gordana 
Published: February 2021

Abstract

Objectives
Novel coronavirus disease (COVID-19) is rapidly spreading all over the world. Although in many cases the infection causes very weak symptoms, it can be severe in patient with diverse chronical diseases and immunological compromising patients. Pregnancy is a unique condition in which mother and fetus peacefully collaborate. Diverse endocrine-immune mechanisms, mostly under progesterone control work together to protect the fetus from maternal immunocompetent cell activation driven rejection. The physiological shift to Th2 dominant environment, while favourable for fetus, it makes mothers susceptible to infective pathogens, making pregnancy during COVID-19 pandemic challenging.

Materials and methods
Studies involving COVID-19 in pregnancy and those analysing changes of immune system induced by COVID-19 were searched in databases such as PubMed, Scopus, Google Scholar and ScienceDirect. Databases were searched using a keyword COVID-19/coronavirus, that was combined with following terms: immune system, pregnancy, oestrogen, or progesterone. Search included studies published up to 01.07.2020. Almost 1,500 articles were found, but only 18 met criteria.

Results
Most frequent symptoms of COVID-19 in mothers infected in the late pregnancy were fever and cough accompanied with lymphopenia and elevated C-reactive protein. Mothers reported to have severe disease had comorbidities and were obese. Low rate of neonatal complications of maternal Sars-Coc-2 infection without neonatal mortality was observed.

Conclusions
Currently available data didn’t show significant relationship between COVID-19 severity and pregnancy and there is no strong evidence that mother’s infection can lead to adverse pregnancy outcome, but further studies are needed to determinate the possible effects of COVID-19 gained during earlier pregnancy.
The study of ischemia modified albumin as an early biomarker of epilepsy in adolescent population: a cross-sectional study
Authors: Asia Priyanka , Sharma Anuj , Kumar Ahirwar Ashok , Garg Seema , Elgiva John Jyoti , Gopal Niranjan 
Published: February 2021

Abstract

Objectives
Epilepsy is one of the most common neurological disorders, diagnosis of which is challenging as many unrelated conditions may mimic seizure. Epilepsy impairs the quality of life of patients due to associated physical and psychological trauma. Epileptic patients are also at increased risk of premature death due to autonomic disturbance and fatal accidents. The aim of the present research work was to study ischemia modified albumin (IMA) as an early biomarker of epilepsy in the adolescent population.

Methods
Twenty-five diagnosed cases of epilepsy and 25 healthy volunteers as control of adolescent group were recruited as study subjects. The study subjects were age and sex matched. Clinical evaluation, routine biochemical parameters and IMA estimation were carried out. Serum IMA was measured by spectrophotometric method.

Results
The mean serum IMA levels were significantly raised in epileptic patients (0.69 ± 0.1 absorbance units [ABSU]) as compared to the healthy control group (0.52 ± 0.24 ABSU) (p=0.004). ROC curve of IMA predicted that at cut off of 0.59 ABSU, the IMA has 96% sensitivity and 52% specificity for diagnosing epilepsy.

Conclusions
IMA may be used as a biomarker for early diagnosis of epilepsy as well as to differentiate epileptic seizure from various non epileptic disorders in the adolescent population.
The association of animated sitcom viewing with humor styles and humor types
Authors: Zsila Ágnes , Urbán Róbert , Orosz Gábor , Demetrovics Zsolt 
Published: February 2021

Abstract
Recently, animated sitcoms such as Family Guy and American Dad have generated considerable interest internationally. This genre is known for its portrayal of controversial political and social issues combined with strategies of malicious humor, exaggeration, and stereotyping. This study addresses the question of whether humor styles and humor types predict viewer interest in animated sitcoms. A total of 1,052 Hungarian adults (41.6% male, M
age = 24.7 years, SD = 7.2) participated in an online survey focusing on animated sitcom viewing habits and the use of humor. It was found that males and younger individuals were more likely to watch animated sitcoms regularly than females and older individuals. As a result of multiple regressions, it was also found that individuals with high levels of self-enhancing and aggressive humor, and low levels of self-defeating humor were more likely to view animated sitcoms. Regarding humor types, individuals with low levels of all humor styles were less likely to watch animated sitcoms regularly. These findings can possibly contribute to a more nuanced understanding of media selection preferences in the level of individual differences.
CFD simulations of stirred-tank reactors for gas-liquid and gas-liquid-solid systems using OpenFOAM®
Authors: Hu Xiaofei , Ilgun Aziz Dogan , Passalacqua Alberto , Fox Rodney O. , Bertola Francesco , Milosevic Miran , Visscher Frans 
Published: February 2021

Abstract
An open-source CFD software OpenFOAM® is used to simulate two multiphase stirred-tank reactors relevant to industrial processes such as slurry polymerization and fuel production. Gas-liquid simulations are first performed in a single-impeller stirred-tank reactor, studied experimentally by Ford, J. J., T. J. Heindel, T. C. Jensen, and J. B. Drake. 2008. “X-Ray Computed Tomography of a Gas-Sparged Stirred-Tank Reactor.” Chemical Engineering Science 63: 2075–85. Three impeller rotation speeds (200, 350 and 700 rpm) with three different bubble diameters (0.5, 1.5 and 2.5 mm) are investigated. Flow patterns compared qualitatively to those from experiments. Compared to the experimental data, the simulations are in relatively good agreement for gas holdup in the reactor. The second multiphase system is a multi-impeller stirred-tank reactor, studied experimentally by Shewale, S. D., and A. B. Pandit. 2006. “Studies in Multiple Impeller Agitated Gas-Liquid Contractors.” Chemical Engineering Science 61: 486–504. Gas-liquid simulations are performed at two impeller rotation speeds (3.75 and 5.08 RPS). The simulated flow patterns agree with published pictures from the experiments. Gas-liquid-solid simulations of the multi-impeller stirred-tank reactor are also carried out at impeller rotation speed 5.08 RPS. The addition of solid particles with a volume fraction characteristic of slurry reactors changes the flow pattern significantly. The bottom Rushton turbine becomes flooded, while the upper pitched-blade downflow turbines present a radial-pumping flow pattern instead of down-pumping. Nonetheless, the solid phase has a similar flow pattern to the liquid phase, indicating that the particles modify the effective density of the fluid.
Analysis between graph-based and Power Transfer Distribution Factors (PTDF)-based model reduction methods in Electric Power Systems
Authors: Monroy-Ortiz Diego A. , Dorado-Rojas Sergio A. , Mojica-Nava Eduardo , Rivera Sergio 
Published: February 2021

Abstract
This article presents a comparison between two different methods to perform model reduction of an Electrical Power System (EPS). The first is the well-known Kron Reduction Method (KRM) that is used to remove the interior nodes (also known as internal, passive, or load nodes) of an EPS. This method computes the Schur complement of the primitive admittance matrix of an EPS to obtain a reduced model that preserves the information of the system as seen from to the generation nodes. Since the primitive admittance matrix is equivalent to the Laplacian of a graph that represents the interconnections between the nodes of an EPS, this procedure is also significant from the perspective of graph theory. On the other hand, the second procedure based on Power Transfer Distribution Factors (PTDF) uses approximations of DC power flows to define regions to be reduced within the system. In this study, both techniques were applied to obtain reduced-order models of two test beds: a 14-node IEEE system and the Colombian power system (1116 buses), in order to test scalability. In analyzing the reduction of the test beds, the characteristics of each method were classified and compiled in order to know its advantages depending on the type of application. Finally, it was found that the PTDF technique is more robust in terms of the definition of power transfer in congestion zones, while the KRM method may be more accurate.
Reactive power and harmonic compensation in a grid-connected photovoltaic system using fuzzy logic controller
Authors: Behera Maheswar Prasad , Ray Pravat Kumar 
Published: February 2021

Abstract
This work investigates the performance of a single-phase grid-connected photovoltaic (PV) system under non-ideal source voltage conditions using a fuzzy logic controller. The single-phase instantaneous reactive power theory has been modified to explore the harmonic and reactive power compensation with distorted grid voltage excitation while transferring active and reactive power to the grid and the non-linear load. Instead of a traditional Proportional-Integral (PI) controller, the proposed method implements a fuzzy logic controller for the extraction of the reference compensating current. This method is compared with the traditional single-phase instantaneous reactive power theory. The advantage associated with a fuzzy logic controller is that it does not need accurate mathematical modeling of the system, instead, it is based upon the linguistic characterization of the input and output variables. Besides, care has been taken to provide uninterrupted compensation throughout the variation of the solar irradiation level. The proposed method has also been verified through a laboratory-developed prototype using a DS1103 processor.
A novel non-isolated dual-input DC-DC boost converter for hybrid electric vehicle application
Authors: Daya John Lionel Febin , Dias Jacintha , Krishna Srinivasan Mohan , Parandhaman Balamurugan , Prabhakaran Prajof 
Published: February 2021

Abstract
This paper proposes a novel non-isolated multi-input dc-dc boost converter for electrical vehicle application. A hybrid system balances the power of the system by using two or more sources. The power between the input sources can be flexibly distributed without any distortion. The charging or discharging of the energy storage systems by other input energy sources can also be monitored in a proper manner and is a feasible task. The design consists of only one inductor and the charging and discharging of the energy storage system decides the operation modes of the converter. In this paper, every operating mode has a small signal model that leads to the control system design for the converter. Simulation and experimental results are provided to prove the validity of the converter and the performance of its control system.
Characterization of H13 steel powder oxidation at different temperatures
Authors: Liu Hengsan , Wang Miaohui , Xu Yifei , Ge Xueyuan , Li Jing , Liang Jinming 
Published: February 2021

Abstract
The oxidation behavior of two kinds of H13 steel powders were studied at different temperatures in air. Both oxidation kinetics and oxidation products were investigated, and the effect of powder particle size distribution on the powder oxidation was also evaluated. In addition, elemental and microstructural analyses were also conducted to characterize the oxide phase formation. Results showed that chromia and spinel were the main phases for both samples after oxidation for 24 h, irrespective of significant descaling.
Effect of heat treatment on the microstructure and properties of 25Cr2MoVA petroleum casing steel
Authors: Cao Pengjun , Zhang Yilong , Li Kejian , Dong Jiling , Wu Wei 
Published: February 2021

Abstract
The 25Cr2MoVA steel was subjected to various heat treatments. We found that the hardness increased when the quenching temperature was in the range of 870 – 910 °C, and then it decreased for the temperature of 910 – 990 °C. The maximum hardness was 553 HV after quenching from 910 °C. Following quenching from 910°C, the 25Cr2Mo-VA steel was tempered in the temperature range of 560 to 750 °C. With an increase in the tempering temperature, the hardness and tensile strength of the material decreased, while the impact toughness increased; the corrosion resistance increased initially and then decreased. The best heat treatment process for the 25Cr2MoVA steel involved quenching form 910 °C and tempering at 650°C for 1 h, the hardness was 362 HV, the tensile strength reached 1 310 MPa, the impact energy reached 149 J, and the material exhibited the best corrosion resistance.
Modeling and analysis of dynamics for a 3D mixed Lorenz system with a damped term
Authors: Li Xianyi , Mirjalol Umirzakov 
Published: February 2021

AbstractThe work in this paper consists of two parts. The one is modelling. After a method of classification for three dimensional (3D) autonomous chaotic systems and a concept of mixed Lorenz system are introduced, a mixed Lorenz system with a damped term is presented. The other is the analysis for dynamical properties of this model. First, its local stability and bifurcation in its parameter space are in detail considered. Then, the existence of its homoclinic and heteroclinic orbits, and the existence of singularly degenerate heteroclinic cycles, are studied by rigorous theoretical analysis. Finally, by using the Poincaré compactification for polynomial vector fields inR3${\mathbb{R}}^{3}$, a global analysis of this system near and at infinity is presented, including the complete description of its dynamics on the sphere near and at infinity. Simulations corroborate corresponding theoretical results. In particular, a possibly new mechanism for the creation of chaotic attractors is proposed. Some different structure types of chaotic attractors are correspondingly and numerically found.
Exploring the effects of awareness and time delay in controlling malaria disease propagation
Authors: Basir Fahad Al , Banerjee Arnab , Ray Santanu 
Published: February 2021

Abstract
In this article, a mathematical model has been derived for studying the dynamics of malaria disease and the influence of awareness-based interventions, for control of the same, that depend on ‘level of awareness’. We have assumed the disease transmission rates from vector to human and from human to vector, as decreasing functions of ‘level of awareness’. The effect of insecticides for controlling the mosquito population is influenced by the level of awareness, modelled using a saturated term. Organizing any awareness campaign takes time. Therefore a time delay has been incorporated in the model. Some basic mathematical properties such as nonnegativity and boundedness of solutions, feasibility and stability of equilibria have been analysed. The basic reproduction number is derived which depends on media coverage. We found two equilibria of the model namely the disease-free and endemic equilibrium. Disease-free equilibrium is stable if basic reproduction number (ℛ0) is less than unity (ℛ0 < 1). Stability switches occur through Hopf bifurcation when time delay crosses a critical value. Numerical simulations confirm the main results. It has been established that awareness campaign in the form of using different control measures can lead to eradication of malaria.
Lipschitz stability of nonlinear ordinary differential equations with non-instantaneous impulses in ordered Banach spaces
Authors: Chen Pengyu , Xin Zhen , Zhang Xuping 
Published: February 2021

Abstract
We consider Lipschitz stability of zero solutions to the initial value problem of nonlinear ordinary differential equations with non-instantaneous impulses on ordered Banach spaces. Using Lyapunov function, Lipschitz stability of zero solutions to nonlinear ordinary differential equation with non-instantaneous impulses is obtained.
The effects of extensive reading on young Korean students’ construction development
Authors: Ro Eunseok , Kim Hyunwoo 
Published: February 2021

AbstractThis study explores how input-focused implicit learning through extensive reading (ER) facilitates construction development in Korean-speaking young EFL students. Twenty-four EFL students, 10–13 years old, participated in ER as an after-school activity for four weeks (ER group). Their construction development in writing was assessed using seven argument structure constructions. The ER group’s performance preceding and following ER activities was compared to 24 young EFL students who did not engage in ER (baseline group). The results showed that the ER group improved their production of ditransitive and caused-motion constructions. Compared to the baseline group, the ER group not only produced a greater number of these constructions, but also used a wider variety of verbs not observed prior to the ER experiences, indicating an expansion of their linguistic knowledge with the target constructions. We conclude by addressing the pedagogical implications for using ER with young EFL students.
The Carbon and Land Footprint of Certified Food Products
Authors: Bellassen Valentin , Drut Marion , Antonioli Federico , Brečić Ružica , Donati Michele , Ferrer-Pérez Hugo , Gauvrit Lisa , Hoang Viet , Knutsen Steinnes Kamilla , Lilavanichakul Apichaya , Majewski Edward , Malak-Rawlikowska Agata , Mattas Konstadinos , Nguyen An , Papadopoulos Ioannis , Peerlings Jack , Ristic Bojan , Tomić Maksan Marina , Török Áron , Vittersø Gunnar , Diallo Abdoul 
Published: February 2021

Abstract
The carbon and land footprint of 26 certified food products – geographical indications and organic products and their conventional references are assessed. This assessment goes beyond existing literature by (1) designing a calculation method fit for the comparison between certified food and conventional production, (2) using the same calculation method and parameters for 52 products – 26 Food Quality Schemes and their reference products – to allow for a meaningful comparison, (3) transparently documenting this calculation method and opening access to the detailed results and the underlying data, and (4) providing the first assessment of the carbon and land footprint of geographical indications. The method used is Life Cycle Assessment, largely relying on the Cool Farm Tool for the impact assessment. The most common indicator of climate impact, the carbon footprint expressed per ton of product, is not significantly different between certified foods and their reference products. The only exception to this pattern are vegetal organic products, whose carbon footprint is 16% lower. This is because the decrease in greenhouse gas emissions from the absence of mineral fertilizers is never fully offset by the associated lower yield. The climate impact of certified food per hectare is however 26% than their reference and their land footprint is logically 24% higher. Technical specifications directly or indirectly inducing a lower use of mineral fertilizers are a key driver of this pattern. So is yield, which depends both on terroir and farming practices. Overall, this assessment reinforces the quality policy of the European Union: promoting certified food is not inconsistent with mitigating climate change.
Consumer Preferences for Green Skin Avocados in the US Market: The Role of Experienced Quality Attributes, Credence Attributes, and Demographic Factors
Authors: Ballen Fredy H. , Evans Edward , Parra-Acosta Yenny Katherine 
Published: February 2021

Abstract
The purpose of this paper is to assess the effect of experienced quality attributes, credence quality attributes and demographic factors affecting green-skin avocado consumption. Data for the present study came from a consumer online survey to 355 avocado consumers. Consumer preferences were modeled by an ordered logit model. Results indicate that experienced quality attributes are the main drivers for green-skin avocado followed by origin and health credence attributes, respectively. Demographic factors other than ethnicity do not play a significant role for green-skin avocado consumption. Among other things, the findings indicate that consumers place a higher valuation on higher fat content compared to low calorie content, implying that the latter attribute should not be touted at the expense of the former. To the extent possible, the industry should focus on cultivars with higher fat content and develop promotional activities to target non-Hispanic consumers. The present study constitutes an effort to contribute to the existing literature as it explores the role of health credence attributes, a topic that has not received much attention.