bluuebunny/crossref_metadata_2025 huggingface dataset:
Picophytoplankton dynamics in a large temperate estuary and impacts of extreme storm events
Authors: Paerl Ryan W. , Venezia Rebecca E. , Sanchez Joel J. , Paerl Hans W.
Published: December 2020

Picophytoplankton (PicoP) are increasingly recognized as significant contributors to primary productivity and phytoplankton biomass in coastal and estuarine systems. Remarkably though, PicoP composition is unknown or not well-resolved in several large estuaries including the semi-lagoonal Neuse River Estuary (NRE), a tributary of the second largest estuary-system in the lower USA, the Pamlico-Albemarle Sound. The NRE is impacted by extreme weather events, including recent increases in precipitation and flooding associated with tropical cyclones. Here we examined the impacts of moderate to extreme (Hurricane Florence, September 2018) precipitation events on NRE PicoP abundances and composition using flow cytometry, over a 1.5 year period. Phycocyanin-richSynechococcus-like cells were the most dominant PicoP, reaching ~ 106cells mL−1, which highlights their importance as key primary producers in this relatively long residence-time estuary. Ephemeral “blooms” of picoeukaryotic phytoplankton (PEUK) during spring and after spikes in river flow were also detected, making PEUK periodically major contributors to PicoP biomass (up to ~ 80%). About half of the variation in PicoP abundance was explained by measured environmental variables. Temperature explained the most variation (24.5%). Change in total dissolved nitrogen concentration, an indication of increased river discharge, explained the second-most variation in PicoP abundance (15.9%). The short-term impacts of extreme river discharge from Hurricane Florence were particularly evident as PicoP biomass was reduced by ~ 100-fold for more than 2 weeks. We conclude that precipitation is a highly influential factor on estuarine PicoP biomass and composition, and show how ‘wetter’ future climate conditions will have ecosystem impacts down to the smallest of phytoplankton.
A preliminary study of bowel rest strategy in the management of Clostridioides difficile infection
Authors: Sugimoto Hiroshi , Yoshihara Ayaka , Yamamoto Takao , Sugimoto Keisuke
Published: December 2020

Clostridioides difficile infection (CDI) is an important nosocomial infection and is the leading cause of infectious diarrhea in hospitalized patients. We aimed to assess the effect of bowel rest on the management of CDI. A single-center retrospective cohort study was conducted. The primary outcome was the composite of the all-cause mortality and CDI recurrence within 30 days. The main secondary outcome was switching from metronidazole to vancomycin. Of the 91 patients with CDI enrolled as the full cohort, 63 patients (69%) and 28 patients (31%) constituted the control group and the bowel rest group, respectively. After one-to-one propensity score matching, a total of 46 patients were included as the matched cohort. In the full cohort, the composite outcome occurred in 19.0% and 14.3% of the patients in the control and the bowel rest group, respectively (p = 0.768). In the matched cohort, it was 17.4% in each group. Although there was no statistically significant difference, the trend of switching was lower in the bowel rest group. The bowel rest may not affect the all-cause mortality and CDI recurrence within 30 days. However, in those prescribed bowel rest, switching from metronidazole to vancomycin may reduce.
A dendronised polymer architecture breaks the conventional inverse relationship between porosity and mechanical properties of hydrogels
Authors: Evans Cameron W. , Ho Diwei , Lee Peter K. H. , Martin Adam D. , Chin Ian L. , Wei Zhenli , Li Hua , Atkin Rob , Choi Yu Suk , Norret Marck , Thordarson Pall , Iyer K. Swaminathan
Published: December 2020

We present a series of synthetic polymer hydrogels which break the traditional correlation between pore size and mechanical properties.
Correlating the axial Zero Field Splitting with the slow magnetic relaxation in GdIIISIMs
Authors: Mayans Júlia , Escuer Albert
Published: December 2020

A possible relation between the value of the axial Zero Field Splitting and the occurrence of field-induced slow magnetic relaxation has been established for a new gadolinium(iii) compound.
Theoretical estimation of size effects on the electronic transport in tailored graphene nanoribbons
Authors: Cheng Na , Chen Feng , Wang Nan , Xiao Zhuocong , Durkan Colm , Zhang Liuyue , Zhao Jianwei
Published: December 2020

Due to the manufacturing error, the configuration of the graphene-based junction can be various. Theoretical simulations on the tailored graphene nanoribbon with the first-principle calculations revealed the effects on the electronic transportation.
The physical significance of the Kamlet–Taftπ* parameter of ionic liquids
Authors: Weiß Nadine , Schmidt Caroline H. , Thielemann Gabi , Heid Esther , Schröder Christian , Spange Stefan
Published: December 2020

The Kamlet–Taft dipolarity/polarizability parametersπ* for various ionic liquids were determined using 4-tert-butyl-2-((dicyanomethylene)-5-[4-N,N-diethylamino)-benzylidene]-Δ3-thiazoline and 5-(N,N-dimethylamino)-5′-nitro-2,2′-bithiophene as solvatochromic probes.
Catalytic mechanism for the isomerization of glucose into fructose over an aluminium-MCM-41 framework
Authors: Liu Li-Juan , Wang Zhao-Meng , Fu Shuai , Si Zhen-Bing , Huang Zhou , Liu Ting-Hao , Yang Hua-Qing , Hu Chang-Wei
Published: December 2020

Al-Containing MCM-41 catalysts exhibit good catalytic activity toward glucose-to-fructose isomerization.
Highly dispersed Pt nanoparticles in the Cs-modified X zeolite with enhancement for toluene side-chain alkylation with methanol
Authors: Hong Zhe , Wang Xiaoxia , Huang Fangtao , Miao Lei , Huang Yanqing , Zhu Zhirong
Published: December 2020

Modification of Cs/X with highly dispersed Pt NPs improved the activity and durability in the side-chain alkylation of toluene.
Water based synthesis of highly conductive GaxLi7−3xLa3Hf2O12 garnets with comparable critical current density to analogous GaxLi7−3xLa3Zr2O12 systems
Authors: Stockham M. P. , Dong B. , James M. S. , Li Y. , Ding Y. , Slater P. R.
Published: December 2020

We report a low temperature, water-based synthesis of Ga0.2Li6.4La3Hf2O12 with high critical current density, cycling stability and no Al3+/Li+ exchange.
A rational review on the effects of sweeteners and sweetness enhancers on appetite, food reward and metabolic/adiposity outcomes in adults
Authors: O'Connor Dominic , Pang Michelle , Castelnuovo Gabriele , Finlayson Graham , Blaak Ellen , Gibbons Catherine , Navas-Carretero Santiago , Almiron-Roig Eva , Harrold Jo , Raben Anne , Martinez J. Alfredo
Published: December 2020

The review focused on outcomes related to obesity an diabetes as affected by sweeteners and included the following keywords: Food Intake, Subjective Appetite, Food Hedonics/Reward, Body Weight, Energy and Glucose, Metabolism/Adiposity Markers.
Dimethyl sulfide facilitates acid catalysed ring opening of the bicyclic monoterpenes in crude sulfate turpentine to affordp-menthadienes in good yield
Authors: Tibbetts Joshua D. , Bull Steven D.
Published: December 2020

Dimethyl sulfide enables efficient acid-catalysed ring opening of bicyclic monoterpenes in turpentine to givep-menthadienes in up to 90% yields.
Self-powered droplet manipulation system for microfluidics based on triboelectric nanogenerator harvesting rotary energy
Authors: Yu Junjie , Wei Xiaoxiang , Guo Yuanchao , Zhang Ziwei , Rui Pinshu , Zhao Yan , Zhang Wen , Shi Shiwei , Wang Peihong
Published: December 2020

A self-powered microfluidic system based on a rotary triboelectric nanogenerator can realize moving, splitting, merging, mixing and chemical transporting of droplets.
Modulated synthesis of thiol-functionalized fcu and hcp UiO-66(Zr) for the removal of silver(i) ions from water
Authors: Moll Bastian , Müller Tim , Schlüsener Carsten , Schmitz Alexa , Brandt Philipp , Öztürk Secil , Janiak Christoph
Published: December 2020

Mercaptoacetate modulation represents an easy way of introducing thiol groups into UiO-MOFs for enhanced uptake of Ag+ from aqueous solutions.
Gas-phase basicity of cyclic guanidine derivatives – a DFT study
Authors: Briš Anamarija , Glasovac Zoran , Margetić Davor
Published: December 2020

Density functional theory calculations (B3LYP) were employed in the study of gas-phase basicity (GB) and pKa of three different types of cyclic guanidines differing in the number of nitrogen atoms incorporated in rings.
Enhancing therapeutic effects and in vivo tracking of adipose tissue-derived mesenchymal stem cells for liver injury using bioorthogonal click chemistry
Authors: Liao Naishun , Zhang Da , Wu Ming , Yang Huanghao , Liu Xiaolong , Song Jibin
Published: December 2020

Adipose tissue-derived mesenchymal stem cell (ADSC)-based therapy is attractive for liver diseases, but the long-term therapeutic outcome is still far from satisfaction due to the low hepatic engraftment efficiency of ADSC transplantation.
Chemical synthesis of quillaic acid, the aglycone of QS-21
Authors: Zeng Zhi-Yong , Liao Jin-Xi , Hu Zhen-Ni , Liu De-Yong , Zhang Qing-Ju , Sun Jian-Song
Published: December 2020

With the easily available protoescigenin as a starting material, a protocol to chemically synthesize quillaic acid was established.
Investigation of the detoxification effect of licorice on Semen Strychni-induced acute toxicity in rats using a HPLC-Q-TOF/MS-based metabolomics approach
Authors: Xiang Yalan , Wang Chao , Wen Jing , Zhang Min , Duan Xiaoyu , Wang Lu , Yan Miao , Li Huande , Fang Pingfei
Published: December 2020

Biomarkers and metabolomic pathway provide an integral understanding for the acute toxicity of Semen Strychni and the detoxification effect of licorice.
Recent advances in graphene-based materials for dye-sensitized solar cell fabrication
Authors: Muchuweni Edigar , Martincigh Bice S. , Nyamori Vincent O.
Published: December 2020

Graphene-based materials can produce high performance and sustainable DSSCs, through tuning of their excellent optoelectronic, mechanical, thermal and chemical properties for use as photoanodes, photosensitizers, electrolytes and counter electrodes.
Markov state models and NMR uncover an overlooked allosteric loop in p53
Authors: Barros Emilia P. , Demir Özlem , Soto Jenaro , Cocco Melanie J. , Amaro Rommie E.
Published: December 2020

Wildtype and Y220C L1 and L6 loops conformational landscape, with MSM-identified L6 states highlighted on the right.
A semiflexible polymer in a gliding assay: reentrant transition, role of turnover and activity
Authors: Shee Amir , Gupta Nisha , Chaudhuri Abhishek , Chaudhuri Debasish
Published: December 2020

An extensible semiflexible filament moving on a motility assay of motor proteins undergoes first order re-entrant phase transition from open chain to spiral as a function of the extension rate and turnover of motor proteins.
Entropy-driven segregation in epoxy-amine systems at a copper interface
Authors: Yamamoto Satoru , Tanaka Keiji
Published: December 2020

Smaller molecules were preferentially segregated at the interface regardless of the epoxy and amine, and this segregation remained after the curing process.
Oral nanotherapeutics with enhanced mucus penetration and ROS-responsive drug release capacities for delivery of curcumin to colitis tissues
Authors: Huang Yamei , Canup Brandon S. B. , Gou Shuangquan , Chen Nanxi , Dai Fangyin , Xiao Bo , Li Changming
Published: December 2020

Pluronic F127 and catalase facilitated the accumulation and drug release of nanoparticles in colitis tissues, and improved their therapeutic outcomes.
Beyond the Bottle: Interdisciplinary Cleft Feeding Care
Authors: Madhoun Lauren L. , Merrell Laura C. , Smith Amanda , Snow Emily , Cherosky Kristen M.
Published: December 2020

Purpose

The importance of individualized and comprehensive pediatric feeding management is well recognized. This type of care is especially important for children with complex medical diagnoses, such as craniofacial anomalies. While feeding therapists are often key to improving feeding outcomes, other essential members are required to comprehensively provide for the unique needs of these infants.

Described here is an example of the structure and function of an interdisciplinary cleft feeding team, which serves patients throughout their infancy and childhood. The role of each member is discussed as well as how each provider works in conjunction with others. Communication and collaboration between these specialists is of utmost importance to care for both the infant and family.

It is important for speech-language pathologists to recognize the feeding needs of children with cleft lip and/or palate and be aware of the roles of various team members on cleft feeding teams available to address any feeding challenges that may arise.

Conclusions

A comprehensive team is often necessary to meet the feeding needs of children with cleft lip and/or palate and their families. This team works collaboratively together to develop appropriate feeding plans through infancy and childhood.
Composite control with observer for switched stochastic systems subject to multiple disturbances and input saturation
Authors: Wei Yunliang , Liu Guo‐Ping , Yang Jun
Published: December 2020

This paper investigates the composite hierarchical anti‐disturbance control problem for switched systems with saturating inputs, in which the multiple disturbances including normal‐bounded disturbances, white noises and nonlinear uncertainties are considered. According to whether the states of the system be available or not, two types of disturbance observers and a state observer are designed, respectively. With the values of the observers, the observer‐based composite controllers are constructed accordingly, under which an uniform form of the closed‐loop system is presented. By utilising the minimum dwell‐time technique and stochastic control theory, a new criterion of the mean‐square exponential stability is presented for the closed‐loop system with a weighted performance level. The design conditions of the observers for the disturbances generated by exosystem and states of the system are proposed by propositions, respectively. Based on the gains of the observers, the solvable synthesis conditions of the composite controllers are presented for the cases of the available and unavailable states of the system. The simulations of GE‐90 aero‐engine model and a numerical example are employed to verify the applicability of the obtained results.
Neural network‐based optimal tracking control for partially unknown discrete‐time non‐linear systems using reinforcement learning
Authors: Zhao Jingang , Vishal Prateek
Published: December 2020

Otimal tracking control of discrete‐time non‐linear systems is investigated in this paper. The system drift dynamics is unknown in this investigation. Firstly, in the light of the discrete‐time non‐linear systems and reference signal, an augmented system is constructed. Optimal tracking control problem of original non‐linear systems is thus transformed into solving optimal regulation problem of the augmented systems. The solution to optimal regulation problem can be found by solving its Hamilton–Jacobi–Bellman (HJB) equation. To solve the HJB equation, a new critic‐actor neural network (NN) structure‐based online reinforcement learning (RL) scheme is proposed to learn the solution of HJB equation while the corresponding optimal control input that minimizes the HJB equation is calculated in a forward‐in‐time manner without requiring any value, policy iterations and the system drift dynamics. The Uniformly Ultimately Boundedness (UUB) of NN weight errors and closed‐loop augmented system states are provided via the Lyapunov theory. Finally, simulation results are given to validate the proposed scheme.
Multi‐objective locating of electric vehicle charging stations considering travel comfort in urban transportation system
Authors: Tadayon‐Roody Pooya , Ramezani Maryam , Falaghi Hamid
Published: December 2020

Environmental concerns of using fossil fuel vehicles and recent developments in electric vehicle (EV) technology have attracted the attention of the international community to use EVs. A design strategy is proposed by simultaneously considering a distribution network and an urban transportation network, that maximises drivers’ travel comfort in urban trips and reduces costs of both charging station (CS) installation and losses. The proposed strategy meets various constraints such as, properly locating CSs in the city, considering traffic volume, taking the shortest route, reducing charging waiting time, limits of bus voltages, power balance, the permissible loading of lines. The travel comfort index corresponds to a situation in which the driver does not experience a depleted battery and successfully finish the trip. Since the movement of vehicles over the course of a day does not follow any particular pattern, unscented transformation is used to investigate the uncertainty in different probabilistic parameters of EVs. Moreover, by clustering the locations of EVs, the optimal locations of EV CSs are determined over the course of the day (in several time steps) using a multi‐objective function based on a GA. The simulation results of the sample urban transportation and distribution networks confirm the efficacy of the proposed method.
Overcurrent protection based on ANNs for smart distribution networks with grid‐connected VSIs
Authors: Bakkar Mostafa , Bogarra S. , Córcoles F. , Iglesias J.
Published: December 2020

Recently, the global concern for protection coordination is growing with the impact of distributed generators connected to medium voltage distribution system. Effective protection strategies need to be developed in order to avoid undesirable tripping when distributed generators based on Voltage Source Inverters are connected to the medium voltage grid. According to Spanish grid code requirements, the inverter controller response in this paper is assessed under grid faults integrating low voltage ride through capabilities. This paper presents a novel use of a communication‐based directional relay system with artificial neural network, an appropriate option for smart grids protection. A protection strategy is proposed using two algorithms. The first algorithm is based on gathering data of all the protective devices in the grid and send it to a centralized controller. The second algorithm is based on a zone controller using the communication between the peer protection devices in the same line. One of the main advantages of the zone controller is that no need to modify the protection devices setting in case of temporary grid reconfigurations. The behaviour of the protection algorithms is validated through both simulations in MATLAB‐Simulink and experimental results.
A generalized method for scattering from wide cavities with specified wave functions
Authors: Bozorgi Mehdi
Published: December 2020

This study developed a generalized solution based on modal expansion for scattering by large cavities with known wave functions placed in an infinite perfect electric plane. Under the assumption of a large cavity, to reduce simulation time and simplify expressions, the half‐space above cavity with a strong singular Green's function is substituted by an arbitrary semi‐waveguide. The fields inside the cavity are expanded by the semi‐waveguide eigenfunctions. The corresponding modes are matched to create a system of linear equations for unknown expansion coefficients. To demonstrate the validity and ability of this method, it is applied to several grooves with different shapes (triangular, circular, and elliptical grooves) and then their scattering signatures are compared with each other. The results are also verified by the results obtained by the method of moment. The measured simulation time for both methods shows that this scheme can be an appropriate candidate for analysing the scattered fields by large cavities.
Application of Concentrated Windings for High-Power Synchronous Wind Generators
Authors: Antipov V.N. , Grozov A.D. , Ivanova A.V.
Published: December 2020

The article analyzes the parameters of various configurations concentrated windings for application in high-power geared and direct drive wind generators. It is specified that the concentrated windings advantages over distributed ones can be fully realized by choosing the right values of pole pairs and the slots number. It is shown that the choice of the winding should take into account not only the highest winding factor, but also to the star of slots for the analysis of the harmonic contents of the magnetomotive force (MMF) and electromotive force (EMF), cogging torque and load torque pulsation. Windings with performance conditions Z=12+6k, 2p=Z ±2, k=0,1,2,3,…having an odd number of pole pairs are recommended for high-power wind generators.
Problems of Electric Power System Management taking into account Sources Distributed Generation
Authors: Toshkhodzhaeva Muhayo , Gracheva Elena , Rahimov Okhunbobo , Dadabaev Shakhboz
Published: December 2020

This article provides a brief overview of the existing problems of managing the electric power system, taking into account the sources of distributed generation. The features of centralized and decentralized power supply systems are considered from the point of view of changing operating conditions, in particular, eliminating the consequences of technological violations. The main goals of the electric power system management have been determined, regardless of the number of sources and the category of consumers in terms of power supply reliability, as well as in emergency and post-emergency modes. The basic principles and sequence of power system management are presented. An algorithm for the efficiency of operation and dispatch control of the power system is considered, methods for ensuring the selective operation of relay protection and automation devices in the presence of several generating capacities are presented. A fragment of an electrical network with four energy sources is shown and the main measures to ensure its normal functioning are proposed.
Influence of the polymeric additives on the process of calcium sulfatedihydrate crystallization
Authors: Ustinova Yulia V.
Published: December 2020

The research is aimed to the clarification of the calcium sulfatedihydrate crystals growth and formation of in the presence of the different polymers based functional additives. The calcium sulfatedihydrate crystals have been synthesized both in the pure form and with the additives. The additives have included a super plasticizer based on a sulfonated melamine-formaldehyde resin (SMF), a methylcellulose (MC) and a redispersible polymer powder based on vinyl acetate, ethylene and vinyl chloride copolymers (VAEVC). The X-ray analysis and the electron microscopy have been applied to identify an influence of the polymer additives over the configuration and size of the calcium sulphate dihydrate crystals. The structural and strength characteristics of the gypsum materials have been also investigated.
Managing a project portfolio in construction
Authors: Babkina Lyudmila , Skotarenko Oksana , Vasiliev Nikolai
Published: December 2020

The article presents a project portfolio management process in a construction company. It includes projects on management system improvement and support. For instance, a project on management automation for online tracking of client orders at various stages of construction will reduce the time for handling client orders and raise the quality of service. As a result, the company will become more competitive and attractive on the construction market.
The systematic approach to designing energy efficient cities
Authors: Shchenikov Yaroslav
Published: December 2020

The novelty of the proposed paper lies in the use of elements of the theory of solving inventive problems TRIZ and the systems theory to achieve the maximum positive synergistic effect of the correct Association of city residents and urban systems.
Smart technology implementation for road traffic management
Authors: Zhuravleva Natalia , Volkova Elena , Solovyev Daniil
Published: December 2020

The escalation of road traffic appears to be a tremendous problem. Various metropolises are influenced by traffic flow congestion and the growth of emissions from petrol usage. In big agglomerations, the expanding quantity of private cars and public transport has caused traffic problems. They have a harmful effect on economy, ecosystem, and on the quality of life in general. It is vital to obtain smart solutions for road traffic management. In this paper, authors propose a way to solve this problem by using smart traffic regulation, which is a part of the bigger smart logistics concept. Agent-based traffic simulation has been chosen to perform this research. This type of modeling is related to the object-oriented way of coding. For modeling and experimental simulation of the intersection in St. Petersburg, AnyLogicmodeling software was used. The results show that proposed algorithm allowed to reduce the average waiting time by 37%. Moreover, the average waiting car number at the intersection has been dropped by 2.5 times after applying the new solution. Thus, projected way of reducing road overload on the selected intersection in St. Petersburg displayed excellent outcomes. However, implementation of the algorithm on other infrastructure objects requires further investigation and analysis.
Research of a Spatial Flow of a Low-Flow Stage of a Svd-22 Centrifugal Compressor by Computational Fluid Dynamics Methods Using Super-Computer Technologies
Authors: Kozhukhov Yuri , Tatchenkova Serafima , Kartashov Sergey , Ivanov Vyacheslav , Nikitin Evgeniy
Published: December 2020

This paper provides the results of the study of a spatial flow in a low-flow stage of a SVD-22 centrifugal compressor of computational fluid dynamics methods using the Ansys CFX 14.0 software package. Low flow stages are used as the last stages of multistage centrifugal compressors. Such multistage compressors are widely used in boosting compressor stations for natural gas, in chemical industries. The flow features in low-flow stages require independent research. This is due to the fact that the developed techniques for designing centrifugal compressor stages are created for medium-flow and high-flow stages and do not apply to low-flow stages. Generally at manufacturing new centrifugal compressors, it is impossible to make a control measurement of the parameters of the working process inside the flow path elements. Computational fluid dynamics methods are widely used to overcome this difficulties. However verification and validation of CFD methods are necessary for accurate modeling of the workflow. All calculations were conducted on one of the SPbPU clusters. Parameters of one cluster node: AMD Opteron 280 2 cores, 8GB RAM. The calculations were conducted using 4 nodes (HP MPI Distributed Parallel startup type) with their full load by parallelizing processes on each node.
Fusion energy
Authors: Romanelli Francesco
Published: December 2020

This paper presents an overview of the main challenges that fusion research is facing on the road to a demonstration power plant. The focus is on magnetic confinement fusion. Most of the challenges are being addressed in the context of the ITER construction and exploitation. These include the demonstration of high fusion gain regimes of operation, the management of high heat and particle loads and the integration of the main technologies of a fusion power plant. In preparation of DEMO, reliable solutions for the breeding blanket and neutron resistant materials have to be developed.
Looking for the bricks of the life in the interstellar medium: The fascinating world of astrochemistry
Authors: Barone Vincenzo , Puzzarini Cristina
Published: December 2020

The discovery in the interstellar medium of molecules showing a certain degree of complexity, and in particular those with a prebiotic character, has attracted great interest. A complex chemistry takes place in space, but the processes that lead to the production of molecular species are a matter of intense discussion, the knowledge still being at a rather primitive stage. Debate on the origins of interstellar molecules has been further stimulated by the identification of biomolecular building blocks, such as nucleobases and amino acids, in meteorites and comets. Since many of the molecules found in space play a role in the chemistry of life, the issue of their molecular genesis and evolution might be related to the profound question of the origin of life itself. Understanding the underlying chemical processes, including the production, reactions and destruction of compounds, requires the concomitant study of spectroscopy, gas-phase reactivity, and heterogeneous processes on dust-grains. The aim of this contribution is to provide a general view of a complex and multifaceted challenge, while focusing on the role played by molecular spectroscopy and quantum-chemical computations. In particular, the derivation of the molecular spectroscopic features and the investigation of gas-phase formation routes of prebiotic species in the interstellar medium are addressed from a computational point of view.
Optimal design of Vertical-Taking-Off-and-Landing UAV wing using multilevel approach
Authors: Yue Hao , Bassir David , Medromi Hicham , Ding Hua , Abouzaid Khaoula
Published: December 2020

In order to overcome the propre disadvantages of FW(Fixed-Wing) and VTOL(Vertical-Taking-Off-and-Landing) UAV (Unmanned Aerial Vehicle) and extend its application, the hybrid drone is invested more in recent years by researchers and several classifications are developed on the part of dual system. In this article, an innovative hybrid UAV is raised and studied by introducing the canard configuration that is coupled with conventional delta wing as well as winglet structure. Profited by Computational Fluid Dynamics (CFD) and Response Surface Method (RSM), a multilevel optimization approach is practically presented and concerned in terms of cruise flight mode: adopted by an experienced-based distribution strategy, the total lift object is respectively assigned into the delta wing (90–95%) and canard wing(5–10%) which is applied into a two-step optimization: the first optimization problem is solved only with the parameters concerned with delta wing afterwards the second optimization is successively concluded to develop the canard configuration considering the optimized delta wing conception. Above all, the optimal conceptual design of the delta and canard wing is realized by achieving the lift goal with less drag performance in cruise mode.
Steinbrecher vom Amazonas
Authors: Moritz Sarah
Published: December 2020

Chanca piedra (Phyllanthus niruri) ist ein tropisches Heilkraut, welches gegen Nierensteine, Entzündungen, Schadstoffe und Viren eingesetzt wird.
Von der heiligen Quelle zum Heilbad von heute
Authors: Bauer Wolfgang
Published: December 2020

Wasser und Quellen werden seit Jahrtausenden in verschiedenen Kulturen für vielfältige Rituale, Bräuche oder Therapien verwendet. Die Verehrung von Quellen ist seit der Altsteinzeit bekannt und besteht teilweise bis heute, zum Beispiel werden einige Quellorte nach wie vor als heilig angesehen. Thermalbäder als Orte der Erholung und Behandlung haben ihren Ursprung im römischen Reich – bis in unsere Zeit hat sich diese Tradition weitergetragen.
Vorsicht beim Import schamanischer Heilmethoden!
Authors: Schlichting Michael
Published: December 2020

„Das zunehmende Unbehagen in unserer Gesellschaft gegenüber Konzepten und Behandlungsmethoden des wissenschaftlich-medizinischen Establishments führt unter Patienten zu einer seit Jahren steigenden Nachfrage nach alternativen Heilverfahren und veranlasst einige Therapeutenkreise zu entsprechenden Angeboten, wobei teils auch explizit schamanische Behandlungsansätze angepriesen werden“, beobachtet Dr. med. Michael Schlichting. Doch welche Risiken verbergen sich hinter dem Import von indigenen Heiltechniken, herausgelöst aus ihrem kulturellen und rituellen Kontext? Dieser zentralen Frage gehen er und die Interviewerin Dr. Claudia Müller-Ebeling nach.
Diversity-Oriented Stereocontrolled Synthesis of Some Piperidine- and Azepane-Based Fluorine-Containing β-Amino Acid Derivatives
Authors: Kiss Loránd , Nonn Melinda , Kara Dominika , Ouchakour Lamiaa , Forró Enikő , Haukka Matti
Published: December 2020

Structural diversity-oriented synthesis of some azaheterocyclic β-amino acid derivatives has been accomplished by selective functionalization of readily available cyclodienes. The stereocontrolled synthetic concept was based on the oxidative ring cleavage of unsaturated cyclic β-amino acids derived from cycloalkadiene, followed by ring closing with double reductive amination, which furnished some conformationally restricted β-amino acid derivatives with a piperidine or azepane core.
The Acoustic Transparency of Waterproof Smartphone Cases
Authors: Fray Sarah M. , Thibodeau Linda M.
Published: December 2020

Phone use is a critical communication event in many people's lives. Audiologists have aimed to assist individuals with hearing loss and phone usage through the use of technology and counseling. To counsel effectively, all contributions to hearing difficulty on the phone must be considered, including the effects of smartphone cases. The purpose of this study was to evaluate the effects on dB output caused by waterproof smartphone cases that cover the ear-level speaker. One waterproof case was tested with three smartphones, two iPhones, and one Android. A second waterproof case was tested with the two iPhones. Results revealed there was significant attenuation of the audio-signal by both waterproof smartphone cases that was great enough in one case/phone combination to potentially result in a complete lack of intelligibility of the signal.
Robots, labor markets, and universal basic income
Authors: Cabrales Antonio , Hernández Penélope , Sánchez Angel
Published: December 2020

Automation is a big concern in modern societies in view of its widespread impact on many socioeconomic issues including income, jobs, and productivity. While previous studies have concentrated on determining the effects on jobs and salaries, our aim is to understand how automation affects productivity, and how some policies, such as taxes on robots or universal basic income, moderate or aggravate those effects. To this end, we have designed an experiment where workers make productive effort decisions, and managers can choose between workers and robots to do these tasks. In our baseline treatment, we measure the effort made by workers who may be replaced by robots, and also elicit firm replacement decisions. Subsequently, we carry out treatments in which workers have a universal basic income of about a fifth of the workers’ median wages, or where there is a tax levy on firms who replace workers by robots. We complete the picture of the impact of automation by looking into the coexistence of workers and robots with part-time jobs. We find that the threat of a robot substitution does not affect the amount of effort exerted by workers. Also, neither universal basic income nor a tax on robots decrease workers’ effort. We observe that the robot substitution tax reduces the probability of worker substitution. Finally, workers that benefit from managerial decisions to not substitute them by more productive robots do not increase their effort level. Our conclusions shed light on the interplay of policy and workers behavior under pervasive automation.
Hierarchical square honeycomb metamaterials with low-frequency broad bandgaps and flat energy bands characteristics
Authors: Sun Pei , Zhang Zhendong , Guo Hui , Liu Ningning , Wang Yansong
Published: December 2020

In this paper, the authors proposed a class of hierarchical square honeycomb metamaterials (HSHMs) with low-frequency broad bandgaps (BGs) and flat energy band characteristics. The mechanical model of the square honeycomb structure and the in-plane mode lattice dynamics model of the HSHMs are presented. The formation mechanism of BGs and flat energy band characteristics are obtained by combining the band structure with transmission spectra, which was calculated using the finite-element method. The numerical results show that the HSHM structure has multiple BGs below 100 Hz, and the transmission spectra are in accordance with the band structure calculations. Additionally, the effects of the scatterer shape and the honeycomb parameters of the elastic element on the BGs are further analyzed and discussed. Based on the analysis, it was concluded that the BGs can be modulated in a wider and lower frequency range by changing the scale factor, the length-to-width ratio of the honeycomb side beam, and layer dislocation. These research results provide a novel structure for the design and application of acoustic metamaterials.
Role of laser pulse asymmetry in electron acceleration in vacuum in the presence of an axial magnetic field
Authors: Kuri Deep Kumar
Published: December 2020

The role played by temporal asymmetry in a linearly polarized laser pulse on the acceleration of an electron in vacuum in the presence of an axial magnetic field has been investigated. The temporal shapes of the laser pulses considered here are Gaussian, positive skew (sharp rise and slow fall), and negative skew (slow rise and sharp fall). Since the pulse amplitude rises sharply in the case of positive skew, the electron experiences a strong intensity gradient during its interaction with the laser pulse, which strengthens the ponderomotive force. On the other hand, the electron experiences a gradual rise in pulse amplitude for a longer time duration in the case of negative skew. The electron energy is observed to be highest for a pulse with negative skew at low laser intensities and for a pulse with positive skew at high laser intensities. In the presence of an axial magnetic field, electron energy is observed to be highest for a pulse with positive skew at both low and high laser intensities.
High electron mobility of AlxGa1−xN evaluated by unfolding the DFT band structure
Authors: Pant Nick , Deng Zihao , Kioupakis Emmanouil
Published: December 2020

We calculate the alloy-disorder-limited electron mobility of AlxGa1−xN from first principles. AlxGa1−xN is a technologically important ultra-wide-bandgap alloy with promise in light emitting diodes and high-power transistors. Alloying introduces statistical disorder, which causes electrons to scatter between different crystal-momentum states, leading to a reduction in mobility for intermediate alloy compositions. The corresponding lifetime, which appears as an energy broadening in the band structure, can be evaluated by unfolding the band structure from the supercell basis to the primitive-cell basis. We fit the first-principles band broadening with a model scattering potential and evaluate the low-field electron mobility using the semiclassical Boltzmann transport equation in the relaxation-time approximation. Our calculated mobility is in agreement with experimental values. We also find the lowest alloy-scattering electron mobility (total electron mobility) across the entire composition range to be 186 cm2/V s (136 cm2/V s), which is comparable to the highest electron mobility predicted in the competitor system, β-(AlxGa1−x)2O3. Our results elucidate the intrinsic limits imposed by alloy disorder on electron transport in AlxGa1−xN.
Two-photon polymerization printed lattices as support structures in multi-shell ICF targets: Platform development and initial assessment
Authors: Scheiner Brett , Schmitt Mark J. , Schmidt Derek , Goodwin Lynne , Marshall Frederic J.
Published: December 2020

Recent interest in fielding direct drive multi-shell targets on the NIF [K. Molvig et al., Phys. Rev. Lett. 116, 255003 (2016) and S. X. Hu et al., Phys. Rev. E 100, 063204 (2019)] has highlighted the need for a low density structure to support the inner shell(s) and to avoid energy loss in the acceleration and collision process. We have developed a two-shell platform to evaluate the use of low density two-photon polymerization (2PP) printed lattices as a support structure between the shells. 2PP structures are an attractive option because they can be produced at densities as low as 5 mg/cc, which is ideal for multi-shell targets, and their 3D structure can be tailored to the user's needs. However, idealized 1D simulations of lattice strut surrogate thin shells indicate that the lattice will only isotropize before the shells collide if the strut thickness is sufficiently fine. This platform makes use of high resolution Fresnel zone plate images to evaluate the uniformity of the post-collision inner shell and provide information on how efficiently the lattice structure isotropizes. As a proof of principle, an initial experiment contrasts the case of 5 μm lattice struts that cause significant disfiguration of the inner shell with the uniform post-collision inner shell in the absence of this material. Finer lattice structures on future experiments will evaluate post-collision inner shell uniformity. This new platform and accompanying diagnostic technique can also be used to evaluate both asymmetry in capsule drive and target non-uniformities with resolution up to mode 40.
A two-fluid analysis of waves in a warm ion–electron plasma
Authors: De Jonghe J. , Keppens R.
Published: December 2020

Following recent work, we discuss waves in a warm ideal two-fluid plasma consisting of electrons and ions starting from a completely general, ideal two-fluid dispersion relation. The plasma is characterized by five variables: the electron and ion magnetizations, the squared electron and ion sound speeds, and a parameter describing the angle between the propagation vector and the magnetic field. The dispersion relation describes six pairs of waves which we label S, A, F, M, O, and X. Varying the angle, it is argued that parallel and perpendicular propagation (with respect to the magnetic field) exhibit unique behavior. This behavior is characterized by the crossing of wave modes which is prohibited at oblique angles. We identify up to six different parameter regimes where a varying number of exact mode crossings in the special parallel or perpendicular orientations can occur. We point out how any ion–electron plasma has a critical magnetization (or electron cyclotron frequency) at which the cutoff ordering changes, leading to different crossing behaviors. These are relevant for exotic plasma conditions found in pulsar and magnetar environments. Our discussion is fully consistent with ideal relativistic MHD and contains light waves. Additionally, by exploiting the general nature of the dispersion relation, phase and group speed diagrams can be computed at arbitrary wavelengths for any parameter regime. Finally, we recover earlier approximate dispersion relations that focus on low-frequency limits and make direct correspondences with some selected kinetic theory results.
Ferroelectric domain structure of Bi2FeCrO6 multiferroic thin films
Authors: Liu Yuan , Lin Jianjun , Zhong Ni , Xiang Ping-Hua , Chen Ye , Yang Pingxiong , Chu Junhao , Duan Chun-Gang , Sun Lin
Published: December 2020

Bi2FeCrO6 (BFCO) multiferroic thin films were deposited on SrRuO3(SRO)/SrTiO3(STO) (001) and STO (001) substrates by a pulsed laser deposition method. High-quality epitaxial BFCO thin films with a typical step-flow surface morphology were successfully prepared. X-ray diffraction reveals that the high phase-purity epitaxial BFCO films with good crystallinity are obtained. Using both piezoelectric force microscopy (PFM) and x-ray reciprocal space mapping, we studied the ferroelectric domain structure and ferroelectricity characterization of BFCO thin films with and without an SRO buffer layer. The ferroelectric domain structure of an epitaxial BFCO film deposited on SRO/STO (001) is characterized by eight polarization variants. However, the ferroelectric domain structure of the epitaxial BFCO film directly grown on the STO (001) substrate is degenerate from eight polarization variants to four or even two. The feasibility of ferroelectric domain engineering is demonstrated by growing BFCO films on STO (001) with and without SRO buffer layers.
A comparative study on the difference of CFD simulations based on a simplified geometry and a more refined BIM based geometry
Authors: Xu Fusuo , Yang Jianzhi , Zhu Xiaowei
Published: December 2020

A strategy of the combination of Computational Fluid Dynamics (CFD) and Building Information Model (BIM) technology was proposed to evaluate the wind environment around a building with complex façades for green building assessment. The Science and Education Building located at the Emerald Lake Campus of the Hefei University of Technology in China was selected as a case study. Two modeling methods, refined modeling by BIM software (BIM model) and traditional simplified modeling by computer aided design software (simplified model, referred to as SM model), were considered. The differences between the CFD results from the two geometry models were carefully examined. Three typical outdoor activity areas were selected to study the wind velocity difference, including the central channel, roof garden, and overhead corridor. The pressure difference between the CFD simulation results of the BIM model and the SM model at the exterior windows of the high-rise building was compared and analyzed. The results show that when a narrow channel is formed between two buildings, the wind velocity of the BIM model at the channel will be significantly lower than that of the SM model. The large “wall-type” components of the building roof will enhance the vortex area. The average pressure difference is greater than 0.5 Pa at the external window of building façades, accounting for up to 39.6%. The maximum pressure difference is as high as 10.13 Pa. The wind velocity difference is as high as 2.65 m/s at the central channel, 4 m/s at the roof garden, and 3.69 m/s at the overhead corridor. These differences will significantly affect the evaluation of the outdoor wind environment in green building assessment.
Computational analysis of gas breakdown modes in direct current micro-plasmas at elevated pressures
Authors: Levko Dmitry , Raja Laxminarayan L.
Published: December 2020

Direct current micro-plasmas in the non-homogeneous electric field are analyzed over a wide pressure range using the self-consistent two-dimensional axisymmetric fluid model. We observe that the breakdown voltage is not the unique function of Pd, where P is the gas pressure and d is the interelectrode spacing, but also depends on the aspect ratio d/r, where r is the anode radius. This result agrees with the data reported in the literature. For fixed d, we find two modes of ionization wave propagation on the right branch of the breakdown curve: an axial streamer mode that is obtained at low pressures and a hollow streamer mode obtained at high pressures. By varying the ballast resistance connected to the anode, we analyze the steady-state parameters of the micro-discharge for the cathode–anode gap of 200 μm. We obtain normal and sub-normal glow modes of the micro-discharge operation. The instability of the latter mode is analyzed.
Bismuth-catalyzed n-type doping and growth evolution of planar silicon nanowires
Authors: Dong Taige , Sun Ying , Wang Junzhuan , Xu Jun , Chen Kunji , Yu Linwei
Published: December 2020

Guided growth of silicon nanowires (SiNWs) into precise locations, via an in-plane solid–liquid–solid (IPSLS) mechanism, is a key basis for scalable integration of SiNW-based electronics, but an effective n-type doping has not yet been accomplished. In this work, we report a bismuth (Bi) catalyzed and doped growth of IPSLS SiNWs, where the incorporation of Bi atoms gives rise to efficient n-type doping, as confirmed by electron dispersion analysis and transfer properties of SiNW transistors. Interestingly, a rich geometry evolution is observed during the Bi-catalyzed planar growth, which evolves from discrete islands to continuous island chains and to uniform segments, prior to a final droplet collapsing/flattening at the end. A growth model has been established to address this peculiar phenomenon, emphasizing the impact of surface/interface tensions on the stability of the leading catalyst droplet. These results provide a solid basis for the construction of more advanced complementary SiNW logics and electronics.