bluuebunny/crossref_metadata_2025 huggingface dataset:
Biocatalytic Synthesis of Natural Dihydrocoumarin by Microbial Reduction of Coumarin
Authors: Serra Stefano , Castagna Antonio , Valentino Mattia
Published: August 2019

Dihydrocoumarin is a natural product of great relevance for the flavour industry. In this work, we describe a study on the biotransformation of the toxic compound coumarin into natural dihydrocoumarin, recognized as safe for food aromatization. To this end, we screened a variety of yeasts and filamentous fungi, isolated from different sources, in order to evaluate their ability to reduce selectively the conjugated double bond of coumarin. Moreover, since coumarin induces cytotoxicity and therefore inhibits cell growth as well as the cell metabolic activity, we tested out different substrate concentrations. All strains were able to convert the substrate, although showing very different conversion rates and different sensitivity to the coumarin concentration. In particular, the yeasts Torulaspora delbrueckii, Kluyveromyces marxianus and the fungus Penicillium camemberti displayed the higher activity and selectivity in the substrate transformation. Among the latter strains, Kluyveromyces marxianus presented the best resistance to substrate toxicity, allowing the biotransformation process even with coumarin concentration up to 1.8 g/L.
Oxygen Atom Function: The Case of Methane Oxidation Mechanism to Synthesis Gas over a Pd Cluster
Authors: Meng Yuanyuan , Xue Yuyuan , Ding Chuanmin , Gao Xiaofeng , Zhang Kan , Liu Ping , Wang Junwen , Li Zhe
Published: August 2019

A dimer model Pd2 was established to study the adsorption of CHx (x = 1–4) and CH4 dehydrogenation, as well as syngas formation using density functional theory (DFT) at the atomic level. Meanwhile, insight into understanding the role of the oxygen atom on the partial oxidation of methane (POM) was also calculated based on a trimer model of Pd2O. For the adsorption of CHx, results showed that the presence of an oxygen atom was a disadvantage to the adsorption of CHx (x = 1–3) species. For CH4 dissociation, the process of CH2→CH + H was found to be the rate-limiting step (RSD) on both Pd2 and Pd2O. H2 was formed by the reaction of CH2 + 2H→CH2 + H2. For CO formation, it was primarily formed in the process of CH + O→CHO→CO + H on both the Pd2 and the Pd2O catalyst. Thermodynamic and kinetic calculations revealed that formation and maintainance of the oxygen atom on the Pd surface could promote a POM reaction to achieve high H2 and CO yield and selectivity. Our study provides a helpful understanding of the effect of an adsorbed oxygen atom on a POM reaction with a Pd catalyst.
RETRACTED: Avola et al. Blue Light Induces Down-Regulation of Aquaporin 1, 3, and 9 in Human Keratinocytes. Cells 2018, 7, 197
Authors:   Cells Editorial Office
Published: August 2019

It has come to our attention that the Western blot data shown in Figure 3 of [...]
Protective to a T: The Role of T Cells during Zika Virus Infection
Authors: Pardy Ryan D. , Richer Martin J.
Published: August 2019

CD4 and CD8 T cells are an important part of the host’s capacity to defend itself against viral infections. During flavivirus infections, T cells have been implicated in both protective and pathogenic responses. Given the recent emergence of Zika virus (ZIKV) as a prominent global health threat, the question remains as to how T cells contribute to anti-ZIKV immunity. Furthermore, high homology between ZIKV and other, co-circulating flaviviruses opens the possibility of positive or negative effects of cross-reactivity due to pre-existing immunity. In this review, we will discuss the CD4 and CD8 T cell responses to ZIKV, and the lessons we have learned from both mouse and human infections. In addition, we will consider the possibility of whether T cells, in the context of flavivirus-naïve and flavivirus-immune subjects, play a role in promoting ZIKV pathogenesis during infection.
Bioink Composition and Printing Parameters for 3D Modeling Neural Tissue
Authors: Fantini Valentina , Bordoni Matteo , Scocozza Franca , Conti Michele , Scarian Eveljn , Carelli Stephana , Di Giulio Anna Maria , Marconi Stefania , Pansarasa Orietta , Auricchio Ferdinando , Cereda Cristina
Published: August 2019

Neurodegenerative diseases (NDs) are a broad class of pathologies characterized by the progressive loss of neurons in the central nervous system. The main problem in the study of NDs is the lack of an adequate realistic experimental model to study the pathogenic mechanisms. Induced pluripotent stem cells (iPSCs) partially overcome the problem, with their capability to differentiate into almost every cell types; even so, these cells alone are not sufficient to unveil the mechanisms underlying NDs. 3D bioprinting allows to control the distribution of cells such as neurons, leading to the creation of a realistic in vitro model. In this work, we analyzed two biomaterials: sodium alginate and gelatin, and three different cell types: a neuroblastoma cell line (SH-SY5Y), iPSCs, and neural stem cells. All cells were encapsulated inside the bioink, printed and cultivated for at least seven days; they all presented good viability. We also evaluated the maintenance of the printed shape, opening the possibility to obtain a reliable in vitro neural tissue combining 3D bioprinting and iPSCs technology, optimizing the study of the degenerative processes that are still widely unknown.
Mitochondrial Involvement in the Adaptive Response to Chronic Exposure to Environmental Pollutants and High-Fat Feeding in a Rat Liver and Testis
Authors: Migliaccio Vincenzo , Di Gregorio Ilaria , Putti Rosalba , Lionetti Lillà
Published: August 2019

In our modern society, exposure to stressful environmental stimuli, such as pollutants and/or chronic high-fat feeding, continuously induce tissular/organ metabolic adaptation to promote cellular survival. In extreme conditions, cellular death and tissular/organ damage occur. Mitochondria, as a cellular energy source, seem to play an important role in facing cellular stress induced by these environmental stimuli. On the other hand, mitochondrial dysfunction and oxidative stress play a key role in environmental stress-induced metabolic diseases. However, little is known about the combined effect of simultaneous exposure to chronic high-fat feeding and environmental pollutants on metabolic alterations at a tissular and cellular level, including mitochondrial dysfunction and oxidative stress induction. Our research group recently addressed this topic by analysing the effect of chronic exposure to a non-toxic dose of the environmental pollutant dichlorodiphenyldichloroethylene (DDE) associated with high-fat feeding in male Wistar rats. In this review, we mainly summarize our recent findings on mitochondrial adaptive response and oxidative stress induction in the liver, the main tissue involved in fat metabolism and pollutant detoxification, and in male gonads, the main targets of endocrine disruption induced by both high-fat feeding and environmental pollutants.
A New Pedigree-Based SNP Haplotype Method for Genomic Polymorphism and Genetic Studies
Authors: Vadva Zareen , Larsen Charles E. , Propp Bennett E. , Trautwein Michael R. , Alford Dennis R. , Alper Chester A.
Published: August 2019

Single nucleotide polymorphisms (SNPs) are usually the most frequent genomic variants. Directly pedigree-phased multi-SNP haplotypes provide a more accurate view of polymorphic population genomic structure than individual SNPs. The former are, therefore, more useful in genetic correlation with subject phenotype. We describe a new pedigree-based methodology for generating non-ambiguous SNP haplotypes for genetic study. SNP data for haplotype analysis were extracted from a larger Type 1 Diabetes Genetics Consortium SNP dataset based on minor allele frequency variation and redundancy, coverage rate (the frequency of phased haplotypes in which each SNP is defined) and genomic location. Redundant SNPs were eliminated, overall haplotype polymorphism was optimized and the number of undefined haplotypes was minimized. These edited SNP haplotypes from a region containing HLA-DRB1 (DR) and HLA-DQB1 (DQ) both correlated well with HLA-typed DR,DQ haplotypes and differentiated HLA-DR,DQ fragments shared by three pairs of previously identified megabase-length conserved extended haplotypes. In a pedigree-based genetic association assay for type 1 diabetes, edited SNP haplotypes and HLA-typed HLA-DR,DQ haplotypes from the same families generated essentially identical qualitative and quantitative results. Therefore, this edited SNP haplotype method is useful for both genomic polymorphic architecture and genetic association evaluation using SNP markers with diverse minor allele frequencies.
The Intrinsically Disordered C-Terminal Domain Triggers Nucleolar Localization and Function Switch of PARN in Response to DNA Damage
Authors: Duan Tian-Li , He Guang-Jun , Hu Li-Dan , Yan Yong-Bin
Published: August 2019

Poly(A)-specific ribonuclease (PARN), a multifunctional multi-domain deadenylase, is crucial to the regulation of mRNA turnover and the maturation of various non-coding RNAs. Despite extensive studies of the well-folding domains responsible for PARN catalysis, the structure and function of the C-terminal domain (CTD) remains elusive. PARN is a cytoplasm–nucleus shuttle protein with concentrated nucleolar distribution. Here, we identify the nuclear and nucleolar localization signals in the CTD of PARN. Spectroscopic studies indicated that PARN-CTD is intrinsically disordered with loosely packed local structures/tertiary structure. Phosphorylation-mimic mutation S557D disrupted the local structure and facilitated the binding of the CTD with the well-folded domains, with no impact on PARN deadenylase activity. Under normal conditions, the nucleolus-residing PARN recruited CBP80 into the nucleoli to repress its deadenylase activity, while DNA damage-induced phosphorylation of PARN-S557 expelled CBP80 from the nucleoli to discharge activity inhibition and attracted nucleoplasm-located CstF-50 into the nucleoli to activate deadenylation. The structure switch-induced function switch of PARN reshaped the profile of small nuclear non-coding RNAs to respond to DNA damage. Our findings highlight that the structure switch of the CTD induced by posttranslational modifications redefines the subset of binding partners, and thereby the RNA targets in the nucleoli.
Alzheimer’s Disease Research Using Human Microglia
Authors: Lue Lih-Fen , Beach Thomas G. , Walker Douglas G.
Published: August 2019

Experimental studies of neuroinflammation in Alzheimer’s disease (AD) have mostly investigated microglia, the brain-resident macrophages. This review focused on human microglia obtained at rapid autopsies. Studies employing methods to isolate and culture human brain microglia in high purity for experimental studies were discussed. These methods were employed to isolate human microglia for investigation of a number of features of neuroinflammation, including activation phenotypes, neurotoxicity, responses to abnormal aggregated proteins such as amyloid beta, phagocytosis, and the effects of aging and disease on microglia cellular properties. In recent years, interest in human microglia and neuroinflammation has been renewed due to the identification of inflammation-related AD genetic risk factors, in particular the triggering receptor expressed on myeloid cells (TREM)-2. Because of the difficulties in developing effective treatments for AD, there has been a general need for greater understanding of the functions of microglia in normal and AD brains. While most experimental studies on neuroinflammation have employed rodent microglia, this review considered the role of human microglia in experimental studies. This review focused on the development of in vitro methodology for the culture of postmortem human microglia and the key findings obtained from experimental studies with these cells.
Challenges in Recruitment and Selection Process: An Empirical Study
Authors: Rozario Sophia Diana , Venkatraman Sitalakshmi , Abbas Adil
Published: August 2019

Today’s knowledge economy very much depends on the value created by the human resource of an organisation. In such a highly competitive environment, organisations have started to pay much attention to the recruitment and selection process, as employees form their main asset. However, the critical factors involved in the employee selection process is not well studied. Previous studies on the recruitment and selection process have been performed mainly to study the performance of the employees and the criteria attracting the right talent leading to employee retention and organizational efficiency. The distinction of this paper is that it studies the existing recruitment and selection process adopted by tertiary and dual education sectors in both urban and regional areas within Australia. The purpose of this research is to conduct an empirical study to identify the critical aspects of the employee selection process that can influence the decision based on different perspectives of the participants such as, hiring members, successful applicants as well as unsuccessful applicants. Various factors such as feedback provision, interview panel participation and preparations, relevance of interview questions, duration and bias were analysed, and their correlations were studied to gain insights in providing suitable recommendations for enhancing the process.
Silicon Heterojunction Solar Cells with p-Type Silicon Carbon Window Layer
Authors: Hsu Chia-Hsun , Zhang Xiao-Ying , Zhao Ming Jie , Lin Hai-Jun , Zhu Wen-Zhang , Lien Shui-Yang
Published: August 2019

Boron-doped hydrogenated amorphous silicon carbide (a-SiC:H) thin films are deposited using high frequency 27.12 MHz plasma enhanced chemical vapor deposition system as a window layer of silicon heterojunction (SHJ) solar cells. The CH4 gas flow rate is varied to deposit various a-SiC:H films, and the optical and electrical properties are investigated. The experimental results show that at the CH4 flow rate of 40 sccm the a-SiC:H has a high band gap of 2.1 eV and reduced absorption coefficients in the whole wavelength region, but the electrical conductivity deteriorates. The technology computer aided design simulation for SHJ devices reveal the band discontinuity at i/p interface when the a-SiC:H films are used. For fabricated SHJ solar cell performance, the highest conversion efficiency of 22.14%, which is 0.33% abs higher than that of conventional hydrogenated amorphous silicon window layer, can be obtained when the intermediate band gap (2 eV) a-SiC:H window layer is used.
Synthesis and Characterization of Crystalline NaY-Zeolite from Belitung Kaolin as Catalyst for n-Hexadecane Cracking
Authors: Krisnandi Yuni K. , Saragi Indah R. , Sihombing Riwandi , Ekananda Rizki , Sari Indah P. , Griffith Benjamin E. , Hanna John V.
Published: August 2019

Crystalline sodium Y (NaY) zeolite has been synthesized using alternative natural source of aluminate and silicate, extracted from natural Belitung kaolin. Prior to use, the natural kaolin was pretreated to obtain fragmented metakaolin and extracted silica. Synthesis was conducted with the addition of NaY gel (two types of NaY seeds were used, prepared from colloidal sillica or sodium silica water) using hydrothermal method for 21 h at 100 °C. The characterization on the as-synthesized zeolites confirmed that the one prepared using colloidal silica-seed has closer structure similarity to NaY zeolite that was synthesized using pro analysis silicate and aluminate sources. Thus, the rest of the synthesis of NaY was carried out using colloidal silica-NaY seed. The NaY zeolites then were converted to HY, through ammonium-exchange followed by calcination, to be tested as cracking catalysts using n-hexadecane as a probe molecule. It shows that HY from metakaolin and extracted silica gives high performance, i.e., n-hexadecane conversion of 58%–64%, also C5-C12 percentage yield and selectivity of 56%–62% and 98%. This work has shown the potential to utilize kaolin as alternative silicate aluminate sources for crystalline zeolite synthesis and to obtain inexpensive and environmentally friendly catalyst materials.
Direct Growth of Flower-Shaped ZnO Nanostructures on FTO Substrate for Dye-Sensitized Solar Cells
Authors: Umar Ahmad , Akhtar Mohammad , Almas Tubia , Ibrahim Ahmed , Al-Assiri Mohammed , Masuda Yoshitake , Rahman Qazi , Baskoutas Sotirios
Published: August 2019

The proposed work reports that ZnO nanoflowers were grown on fluorine-doped tin oxide (FTO) substrates via a solution process at low temperature. The high purity and well-crystalline behavior of ZnO nanoflowers were established by X-ray diffraction. The morphological characteristics of ZnO nanoflowers were clearly revealed that the grown flower structures were in high density with 3D floral structure comprising of small rods assembled as petals. Using UV absorption and Raman spectroscopy, the optical and structural properties of the ZnO nanoflowers were studied. The photoelectrochemical properties of the ZnO nanoflowers were studied by utilizing as a photoanode for the manufacture of dye-sensitized solar cells (DSSCs). The fabricated DSSC with ZnO nanoflowers photoanode attained reasonable overall conversion efficiency of ~1.40% and a short-circuit current density (JSC) of ~4.22 mA cm−2 with an open circuit voltage (VOC) of 0.615 V and a fill factor (FF) of ~0.54. ZnO nanostructures have given rise to possible utilization as an inexpensive and efficient photoanode materials for DSSCs.
Implementing Metal-Organic Frameworks for Natural Gas Storage
Authors: Mahmoud Eyas , Ali Labeeb , El Sayah Asmaa , Alkhatib Sara Awni , Abdulsalam Hend , Juma Mouza , Al-Muhtaseb Ala’a H.
Published: August 2019

Methane can be stored by metal-organic frameworks (MOFs). However, there remain challenges in the implementation of MOFs for adsorbed natural gas (ANG) systems. These challenges include thermal management, storage capacity losses due to MOF packing and densification, and natural gas impurities. In this review, we discuss discoveries about how MOFs can be designed to address these three challenges. For example, Fe(bdp) (bdp2− = 1,4-benzenedipyrazolate) was discovered to have intrinsic thermal management and released 41% less heat than HKUST-1 (HKUST = Hong Kong University of Science and Technology) during adsorption. Monolithic HKUST-1 was discovered to have a working capacity 259 cm3 (STP) cm−3 (STP = standard temperature and pressure equivalent volume of methane per volume of the adsorbent material: T = 273.15 K, P = 101.325 kPa), which is a 50% improvement over any other previously reported experimental value and virtually matches the 2012 Department of Energy (Department of Energy = DOE) target of 263 cm3 (STP) cm−3 after successful packing and densification. In the case of natural gas impurities, higher hydrocarbons and other molecules may poison or block active sites in MOFs, resulting in up to a 50% reduction of the deliverable energy. This reduction can be mitigated by pore engineering.
Gaussian Mean Field Regularizes by Limiting Learned Information
Authors: Kunze Julius , Kirsch Louis , Ritter Hippolyt , Barber David
Published: August 2019

Variational inference with a factorized Gaussian posterior estimate is a widely-used approach for learning parameters and hidden variables. Empirically, a regularizing effect can be observed that is poorly understood. In this work, we show how mean field inference improves generalization by limiting mutual information between learned parameters and the data through noise. We quantify a maximum capacity when the posterior variance is either fixed or learned and connect it to generalization error, even when the KL-divergence in the objective is scaled by a constant. Our experiments suggest that bounding information between parameters and data effectively regularizes neural networks on both supervised and unsupervised tasks.
A New Surrogating Algorithm by the Complex Graph Fourier Transform (CGFT)
Authors: Belda Jordi , Vergara Luis , Safont Gonzalo , Salazar Addisson , Parcheta Zuzanna
Published: August 2019

The essential step of surrogating algorithms is phase randomizing the Fourier transform while preserving the original spectrum amplitude before computing the inverse Fourier transform. In this paper, we propose a new method which considers the graph Fourier transform. In this manner, much more flexibility is gained to define properties of the original graph signal which are to be preserved in the surrogates. The complex case is considered to allow unconstrained phase randomization in the transformed domain, hence we define a Hermitian Laplacian matrix that models the graph topology, whose eigenvectors form the basis of a complex graph Fourier transform. We have shown that the Hermitian Laplacian matrix may have negative eigenvalues. We also show in the paper that preserving the graph spectrum amplitude implies several invariances that can be controlled by the selected Hermitian Laplacian matrix. The interest of surrogating graph signals has been illustrated in the context of scarcity of instances in classifier training.
Organising Levels of Organisation for Biology Education: A Systematic Review of Literature
Authors: Schneeweiß Niklas , Gropengießer Harald
Published: August 2019

Many authors suggest an explicit reflection on the levels of organisation, based on known difficulties related to understanding biological systems. Yet, there is no scientific consensus on the characteristics of biological levels and the quality of their relationships. This review intends to present the state of the current discussion in order to establish an educational argumentation as a basis for the development of learning environments and teaching experiments in biology education. For this purpose, we conducted a systematic literature review. Three databases (BIOSIS, ERIC, Fachportal-Pädagogik) were searched for literature on levels of organisation. The papers were analysed by means of a qualitative content analysis based on the following research questions: (1) Which levels of organisation do the authors name? (2) How do the authors describe the levels of organisation? (3) How do the authors describe the relationship between different levels of organisation? (4) How do the authors describe the challenges of these levels for biological education? (5) How do the authors describe the benefit of these levels for biological education? Based on the results, we propose a system of levels that features the concept of zooming-in and makes the relationships between the levels explicit.
SimCity in Infrastructure Management Education
Authors: Arnold Uwe , Söbke Heinrich , Reichelt Maria
Published: August 2019

Simulation games offer a safe space to experiment with system models and provide learning experiences about interdependencies and thus, are considered to foster the development of a deeper understanding of systems. This article describes the use of SimCity in the university course Infrastructure Management, which has been in continuous operation since 2002. Methodologically, a total of four events were observed. Students’ motivation, the didactic scenario and the perceived learning outcomes were examined with the help of a focus group discussion and questionnaires. The didactic scenario shows characteristics not described in this combination in the literature to date: (1) the moderated open, simultaneous and competitive play in groups, (2) the used regional planning scenario and (3) the long, regular period of application of more than 15 years. The results show that SimCity 4 can still serve as a platform for exciting learning scenarios more than 15 years after its initial release. It could also be shown that the didactic scenario motivates the students and that SimCity also generates gaming fun. Furthermore, it could be argued that a regional scenario can be implemented by simple means and is perceived as motivating by the students. Furthermore, this study indicates that even a technically complex and fast-moving medium such as a computer game can be used in a didactic scenario over a longer period with limited effort. Nevertheless, the challenge of game aging should be actively addressed. Furthermore, the study revealed that game-based learning still faces challenges with being recognized by students as a serious learning activity.
Beyond Snap-In: A Hybrid Nonlinear Control Approach for Actuators Possessing a Square-Law Characteristic
Authors: Li Chong , Wang Xinning , Hou Renyu , Dean Robert N. , Zhou Liqin , Dong Yuhang , Song Dalei
Published: August 2019

The undesired square-law characteristics in micro-electrostatic actuators and magnetic solenoids results in a limited stable range, which reduces their application fields and performance. This research investigated the isomorphic dynamics in these actuators and observed that the nonlinear drive force and the uncertain time delay are the challenges for the full range position controller design. A hybrid nonlinear control scheme includes an input–output linearization controller and a feedback posicast compensator for targeting these problems with abundant stability margin. The experimental results show that the stable range has been extended from 33% to 80%. Furthermore, it is the first literature report of this type of actuator that can track sinusoidal motion beyond the conventional stable range with an amplitude of 70% of the total range. This contribution can significantly enhance the performance of micro-sensors or expand the usage of electrostatic/magnetic actuators in motion-control systems.
SAND/3: SDN-Assisted Novel QoE Control Method for Dynamic Adaptive Streaming over HTTP/3
Authors: Guillen Luis , Izumi Satoru , Abe Toru , Suganuma Takuo
Published: August 2019

Dynamic Adaptive Streaming over HTTP (DASH) is a widely used standard for video content delivery. Video traffic, most of which is generated from mobile devices, is shortly to become the most significant part of Internet traffic. Current DASH solutions only consider either client- or server-side optimization, leaving other components in DASH (e.g., at the transport layer) to default solutions that cause a performance bottleneck. In that regard, although it is assumed that HTTP must be necessarily transported on top of TCP, with the latest introduction of HTTP/3, it is time to re-evaluate its effects on DASH. The most substantial change in HTTP/3 is having Quick UDP Internet Connections (QUIC) as its primary underlying transport protocol. However, little is still know about the effects on standard DASH client-based adaption algorithms when exposed to the future HTTP/3. In this paper, we present SAND/3, an SDN (Software Defined Networking)-based Quality of Experience (QoE) control method for DASH over HTTP/3. Since the official deployment of HTTP/3 has not been released yet, we used the current implementation of Google QUIC. Preliminary results show that, by applying SAND/3, which combines information from different layers orchestrated by SDN to select the best QoE, we can obtain steadier media throughput, reduce the number of quality shifts in at least 40%, increase the amount downloaded content at least 20%, and minimize video interruptions compared to the current implementations regardless of the client adaption algorithm.
Use of Markov Decision Processes in the Evaluation of Corrective Maintenance Scheduling Policies for Offshore Wind Farms
Authors: Seyr Helene , Muskulus Michael
Published: August 2019

Optimization of the maintenance policies for offshore wind parks is an important step in lowering the costs of energy production from wind. The yield from wind energy production is expected to fall, which will increase the need to be cost efficient. In this article, the Markov decision process is presented and how it can be applied to evaluate different policies for corrective maintenance planning. In the case study, we show an alternative to the current state-of-the-art policy for corrective maintenance that will achieve a cost-reduction when energy production prices drop below the current levels. The presented method can be extended and applied to evaluate additional policies, with some examples provided.
Numerical Investigations of a Tip Turbine Aerodynamic Design in a Propulsion System for VTOL Vehicles
Authors: Xiang Xin , Huang Guoping , Chen Jie , Li Lei , Lu Weiyu
Published: August 2019

High thrust and low specific fuel consumption (SFC) are important for vertical takeoff and landing (VTOL) vehicles. An effective way to decrease the SFC is to increase the bypass ratio (BPR) of the propulsion system. The air-driven fan (or fan-in-wing) has a very high bypass ratio and has proved to be successful in VTOL aircrafts. However, the tip turbine that extracts energy for the air-driven fan faces the low-solidity problem and performs inadequately. In this study, we developed a high-reaction method for the aerodynamic design of a tip turbine to solve the low-solidity problem. A typical tip turbine was selected and designed by both conventional and high-reaction methods. Three-dimensional flow fields were numerically simulated through a Reynolds-averaged Navier-Stokes (RANS)-based computational fluid dynamics (CFD) method. The energy extraction rate was proposed to evaluate and display the energy extraction capability of the turbine. The results showed that the high-reaction turbine could solve the low-solidity problem and significantly increase the isentropic efficiency from approximately 80.0% to 85.6% and improve the isentropic work by 71.9% compared with the conventional method (from 10.28 kW/kg to 17.67 kW/kg).
Feasibility Study on Energy Audit and Data Driven Analysis Procedure for Building Energy Efficiency: Bench-Marking in Korean Hospital Buildings
Authors: Hwang Dong Kon , Cho Jinkyun , Moon Junghwan
Published: August 2019

Growths in population, increasing demand for health care services and comfort levels, together with patients on the rise in time spent inside hospitals, assure the upward trend that energy demand will continue in the future. Since the hospital buildings operate 24 hours, 365 days a year for the treatment and restoration of patients, they are approximately 2–3 times more energy-intensive than normal buildings. For this reason, energy efficiency in hospitals is one of the prime objectives for energy policy at regional, national and international levels. This study aims to find how meaningful energy performance, reflecting good energy management and energy conservation measures (ECMs), can be operated for hospital buildings, a category encompassing complex buildings with different systems and large gaps between them. Energy audit allows us to obtain knowledge from the healthcare facility, in order to define and tune data driven analysis rules. The use of benchmarking in the energy audit of healthcare facilities enables immediate comparison between hospitals. Data driven energy analysis also allows ascertaining their expected energy consumption and estimating the possible savings margin by using the building energy flow chart. In the 2015–2017 periods, bench-marking of four public hospitals in Seoul were audited for the energy consumption related to weather conditions, total area, bed numbers, employee numbers, and analyzed for building energy flow by zones, energy sources, systems and equipment. This is a practice-based learning in a hospital project. The results reveal that the average annual energy consumption of a hospital under normal conditions, and energy efficiency factors are divided into energy baselines, energy consumption goals for energy saving and energy usage trends for setting ECMs, respectively. The indicator dependent on the area of inpatients (number of beds) proved to be the most suitable as a reference to quantify the energy consumption of a hospital.
Distribution of the Strip Tensions with Slip Control in Strip Processing Lines
Authors: Magura Daniel , Kyslan Karol , Padmanaban Sanjeevikumar , Fedák Viliam
Published: August 2019

The control of tension in processing lines for metal strips tackles several problems. The process of achieving high tension driven by a multi-motor drive system, where the motors are mechanically coupled by a strip, is affected by the maximal torque of each drive, by friction between the strip and the surface of the tension roll, and by the wrap angle. The friction itself and the wrap angle are described by the eµα factor, which can be also calculated as the ratio of tensions in the strip in the previous section and subsequent section of the multi-motor drive. In this paper, an algorithm for the proper distribution of tensions in the strip for a multi-motor drive system of a continuous processing line is revealed. The algorithm ensures the tension distribution among particular drives of the tension leveler while respecting the physical limits of the drives and also preserving the desired conditions of a constant ratio between the input and output tensions for all drives in the leveler. The algorithm also prevents overloading of the drives. Finally, the algorithm was implemented in a control system of a strip processing line, and the obtained results correspond with the simulations. This, in turn, confirms the correctness of the algorithm design.
Impact of Electrically Assisted Turbocharger on the Intake Oxygen Concentration and Its Disturbance Rejection Control for a Heavy-duty Diesel Engine
Authors: Wu Chao , Song Kang , Li Shaohua , Xie Hui
Published: August 2019

The electrically assisted turbocharger (EAT) shows promise in simultaneously improving the boost response and reducing the fuel consumption of engines with assist. In this paper, experimental results show that 7.8% fuel economy (FE) benefit and 52.1% improvement in transient boost response can be achieved with EAT assist. EAT also drives the need for a new feedback variable for the air system control, instead of the exhaust recirculation gas (EGR) rate that is widely used in conventional turbocharged engines (nominal system). Steady-state results show that EAT assist allows wider turbine vane open and reduces pre-turbine pressure, which in turn elevates the engine volumetric efficiency hence the engine air flow rate at fixed boost pressure. Increased engine air flow rate, together with the reduced fuel amount necessary to meet the torque demand with assist, leads to the increase of the oxygen concentration in the exhaust gas (EGR gas dilution). Additionally, transient results demonstrate that the enhanced air supply from the compressor and the diluted EGR gas result in a spike in the oxygen concentration in the intake manifold (Xoim) during tip-in, even though there is no spike in the EGR rate response profile. Consequently, there is Nitrogen Oxides (NOx) emission spike, although the response of boost pressure and EGR rate is smooth (no spike is seen). Therefore, in contrast to EGR rate, Xoim is found to be a better choice for the feedback variable. Additionally, a disturbance observer-based Xoim controller is developed to attenuate the disturbances from the turbine vane position variation. Simulation results on a high-fidelity GT-SUTIE model show over 43% improvement in disturbance rejection capability in terms of recovery time, relative to the conventional proportional-integral-differential (PID) controller. This Xoim-based disturbance rejection control solution is beneficial in the practical application of the EAT system.
Special Issue “Intelligent Control in Energy Systems”
Authors: Dounis Anastasios
Published: August 2019

The editor of this special issue on “Intelligent Control in Energy Systems” have made an attempt to publish a book containing original technical articles addressing various elements of intelligent control in energy systems. The response to our call had 60 submissions, of which 27 were published submissions and 33 were rejections. This book contains 27 technical articles and one editorial. All have been written by authors from 15 countries (China, Netherlands, Spain, Tunisia, United States of America, Korea, Brazil, Egypt, Denmark, Indonesia, Oman, Canada, Algeria, Mexico, and Czech Republic), which elaborated several aspects of intelligent control in energy systems. It covers a broad range of topics including fuzzy PID in automotive fuel cell and MPPT tracking, neural network for fuel cell control and dynamic optimization of energy management, adaptive control on power systems, hierarchical Petri Nets in microgrid management, model predictive control for electric vehicle battery and frequency regulation in HVAC systems, deep learning for power consumption forecasting, decision tree for wind systems, risk analysis for demand side management, finite state automata for HVAC control, robust μ-synthesis for microgrid, and neuro-fuzzy systems in energy storage.
Separating Regressions for Model Fitting to Reduce the Uncertainty in Forest Volume-Biomass Relationship
Authors: Liu Caixia , Zhou Xiaolu , Lei Xiangdong , Huang Huabing , Zhou Carl , Peng Changhui , Wang Xiaoyi
Published: August 2019

The method of forest biomass estimation based on a relationship between the volume and biomass has been applied conventionally for estimating stand above- and below-ground biomass (SABB, t ha−1) from mean growing stock volume (m3 ha−1). However, few studies have reported on the diagnosis of the volume-SABB equations fitted using field data. This paper addresses how to (i) check parameters of the volume-SABB equations, and (ii) reduce the bias while building these equations. In our analysis, all equations were applied based on the measurements of plots (biomass or volume per hectare) rather than individual trees. The volume-SABB equation is re-expressed by two Parametric Equations (PEs) for separating regressions. Stem biomass is an intermediate variable (parametric variable) in the PEs, of which one is established by regressing the relationship between stem biomass and volume, and the other is created by regressing the allometric relationship of stem biomass and SABB. A graphical analysis of the PEs proposes a concept of “restricted zone,” which helps to diagnose parameters of the volume-SABB equations in regression analyses of field data. The sampling simulations were performed using pseudo data (artificially generated in order to test a model) for the model test. Both analyses of the regression and simulation demonstrate that the wood density impacts the parameters more than the allometric relationship does. This paper presents an applicable method for testing the field data using reasonable wood densities, restricting the error in field data processing based on limited field plots, and achieving a better understanding of the uncertainty in building those equations.
Basidiomycotic Yeast Cryptococcus diffluens Converts l-Galactonic Acid to the Compound on the Similar Metabolic Pathway in Ascomycetes
Authors: Matsubara Takeo , Kataoka Michihiko , Kishida Masao
Published: August 2019

(1) Background: It has been shown that d-galacturonic acid is converted to l-galactonic acid by the basidiomycotic yeast, Cryptococcus diffluens. However, two pathways are hypothesized for the l-galactonic acid conversion process in C. diffluens. One is similar to the conversion process of the filamentous fungi in d-galacturonic acid metabolism and another is the conversion process to l-ascorbic acid, reported in the related yeast, C. laurentii. It is necessary to determine which, if either, process occurs in C. diffluens in order to produce novel value-added products from d-galacturonic acid using yeast strains. (2) Methods: The diethylaminoethy (DEAE)-fractionated enzyme was prepared from the cell-free extract of C. diffluens by the DEAE column chromatography. The l-galactonic acid conversion activity was assayed using DEAE-fractionated enzyme and the converted product was detected and fractionated by high-performance anion-exchange chromatography. Then, the molecular structure was identified by nuclear magnetic resonance analysis. (3) Results: The product showed similar chemical properties to 2-keto-3-deoxy-l-galactonic acid (l-threo-3-deoxy-hexulosonic acid). (4) Conclusions: It is suggested that l-galactonic acid is converted to 2-keto-3-deoxy-l-galactonic acid by dehydratase in C. diffluens. The l-galactonic acid conversion process of C. diffluens is a prioritized pathway, similar to the pathway of ascomycetes.
Modeling of Cumulative QoE in On-Demand Video Services: Role of Memory Effect and Degree of Interest
Authors: Nguyen Duc Tho , Minh Tran Chanh , Tan Phan Xuan , Kamioka Eiji
Published: August 2019

The growing demand on video streaming services increasingly motivates the development of a reliable and accurate models for the assessment of Quality of Experience (QoE). In this duty, human-related factors which have significant influence on QoE play a crucial role. However, the complexity caused by multiple effects of those factors on human perception has introduced challenges on contemporary studies. In this paper, we inspect the impact of the human-related factors, namely perceptual factors, memory effect, and the degree of interest. Based on our investigation, a novel QoE model is proposed that effectively incorporates those factors to reflect the user’s cumulative perception. Evaluation results indicate that our proposed model performed excellently in predicting cumulative QoE at any moment within a streaming session.
Have Historical Land Use/Land Cover Changes Triggered a Fire Regime Shift in Central Spain?
Authors: Montiel-Molina Cristina , Vilar Lara , Romão-Sequeira Catarina , Karlsson Oskar , Galiana-Martín Luis , Madrazo-García de Lomana Gonzalo , Palacios-Estremera Ma Teresa
Published: August 2019

Fire is one of the main disturbance factors shaping the landscape, and landscape is a key driver of fire behavior. Considering the role played by land use and land cover (LULC) changes as the main driver of landscape dynamics, the aim of this study was to calculate and analyze (i) the real impact of fire on LULC changes and (ii) how these LULC changes were influencing the fire regime. We used methods of historical geography and socio-spatial systemic analysis for reconstructing and assessing the LULC change and fire history in six case studies in the Central Mountain System (Spain) from archival documentary sources and historical cartography. The main result is an accurate dataset of fire records from 1497 to 2013 and a set of LULC maps for three time points (1890s–1930s, 1956–1957, and the 2000s). We have shown the nonlinear evolution of the fire regime and the importance of the local scale when assessing the interaction of landscape dynamics and fire regime variation. Our findings suggest that LULC trends have been the main influencing factor of fire regime variation in Central Spain since the mid-19th century.
Investigation of Hydrodynamically Dominated Membrane Rupture, Using Smoothed Particle Hydrodynamics–Finite Element Method
Authors: Asadi Hossein , Taeibi-Rahni Mohammad , Akbarzadeh Amir Mahdi , Javadi Khodayar , Ahmadi Goodarz
Published: August 2019

The rupturing process of a membrane, located between two fluids at the center of a three-dimensional channel, is numerically investigated. The smoothed particle hydrodynamics (SPH) and the finite element method (FEM) are used, respectively, for modeling the fluid and solid phases. A range of pressure differences and membrane thicknesses are studied and two different rupturing processes are identified. These processes differ in the time scale of the rupture, the location of the rupture initiation, the level of destruction and the driving mechanism.
Arboreal Epiphytes in the Soil-Atmosphere Interface: How Often Are the Biggest “Buckets” in the Canopy Empty?
Authors: Hargis Hailey , Gotsch Sybil G. , Porada Philipp , Moore Georgianne W. , Ferguson Briana , Van Stan John T.
Published: August 2019

Arboreal epiphytes (plants residing in forest canopies) are present across all major climate zones and play important roles in forest biogeochemistry. The substantial water storage capacity per unit area of the epiphyte “bucket” is a key attribute underlying their capability to influence forest hydrological processes and their related mass and energy flows. It is commonly assumed that the epiphyte bucket remains saturated, or near-saturated, most of the time; thus, epiphytes (particularly vascular epiphytes) can store little precipitation, limiting their impact on the forest canopy water budget. We present evidence that contradicts this common assumption from (i) an examination of past research; (ii) new datasets on vascular epiphyte and epi-soil water relations at a tropical montane cloud forest (Monteverde, Costa Rica); and (iii) a global evaluation of non-vascular epiphyte saturation state using a process-based vegetation model, LiBry. All analyses found that the external and internal water storage capacity of epiphyte communities is highly dynamic and frequently available to intercept precipitation. Globally, non-vascular epiphytes spend <20% of their time near saturation and regionally, including the humid tropics, model results found that non-vascular epiphytes spend ~1/3 of their time in the dry state (0–10% of water storage capacity). Even data from Costa Rican cloud forest sites found the epiphyte community was saturated only 1/3 of the time and that internal leaf water storage was temporally dynamic enough to aid in precipitation interception. Analysis of the epi-soils associated with epiphytes further revealed the extent to which the epiphyte bucket emptied—as even the canopy soils were often <50% saturated (29–53% of all days observed). Results clearly show that the epiphyte bucket is more dynamic than currently assumed, meriting further research on epiphyte roles in precipitation interception, redistribution to the surface and chemical composition of “net” precipitation waters reaching the surface.
Children’s Dental Sealant Use and Caries Prevalence Affected by National Health Insurance Policy Change: Evidence from the Korean National Health and Nutrition Examination Survey (2007–2015)
Authors: Sohn Minsung , Park Sujin , Lim Sungwon , Park Hee-Jung
Published: August 2019

We evaluated the effect of the National Health Insurance (NHI) policy including dental sealant on changes in the prevalence of sealant and caries, and examined how NHI affected sealant utilization and untreated caries in children from diverse income groups in South Korea. We used a multivariate logistic regression analysis to explore the effects of three stages of dental sealant policy (pre-policy: 2007–2009, first post-policy: 2010–2012, and second post-policy: 2013–2015) on the prevalence of dental sealant and untreated caries. Participant data (N = 8161, aged 6–14 years) were derived from the Korea National Health and Nutrition Examination Survey (2007–2015). We also conducted subgroup analysis to determine the effects of the NHI policy on dental sealant and untreated caries by income level. Implementation of dental insurance coverage was associated with higher likelihood of using dental sealant (odds ratio (OR) = 1.39 (95% confidence interval (CI): 1.18–1.63) for the first period and OR = 1.58 (95% CI: 1.33–1.87) for the second period) and lower odds of having untreated caries (OR = 0.79 (95% CI: 0.64–0.98) for the first period and OR = 0.65 (95% CI: 0.51–0.83) for the second period) after controlling for covariates. Results revealed that there was a greater prevalence of dental sealant and a lower prevalence of untreated caries in both middle- and low-income households compared to high-income households. The higher prevalence of dental sealant and lower untreated caries after the policy implementation. Moreover, we demonstrated children from low-or middle-income households were more associated with increasing dental sealant use and a declining prevalence of caries.