bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulation of a Steel-Aluminum Composite Material Subjected to Rolling Contact Fatigue
Authors: Hwang Jae-Il , Coors Timm , Pape Florian , Poll Gerhard
Published: December 2019

Rolling bearings are frequently used machine elements in mechanical assemblies to connect rotating parts. Resource efficiency and reliability enhancement are considered to be important factors of rolling bearing development. One of the ways to meet these requirements is the tailored forming (TF) technology, which enables the functionalization of several metal layer composites in a single component. The so-called hybrid machine elements can be produced by co-extrusion of aluminum and steel and subsequent die forging, heat treatment, and machining. The TF rolling bearings made by this process can provide optimized characteristics that use aluminum to reduce weight and steel for a highly loaded contact zone between a rolling element and a bearing raceway. To evaluate the applicability and the potential of this technology, theoretical investigations are presented in this paper. The stress distribution under fully flooded conditions, caused by an external load in the contact between a rolling element and the TF outer ring of an angular contact ball bearing, is analyzed statically with the finite element method. The fatigue life of the TF component can be calculated for different external axial loads and manufacturing parameters, such as steel-to-aluminum volume ratios and osculation. As a damage model, the Ioannides and Harris fatigue model and the Dang Van multiaxial fatigue criterion were used. The results show that the fatigue life has high sensitivity to the steel-to-aluminum volume ratio. For the hybrid component with a steel layer thickness of 3 mm, 90 percent of the fatigue life of pure 100Cr6 steel bearing bushings is reached. In this FE model, residual stresses due to machining processes can be regarded as an initial state, which can increase the fatigue life of this TF machine component.
Analysis of Structure-Preserving Discrete Models for Predator-Prey Systems with Anomalous Diffusion
Authors: Alba-Pérez Joel , Macías-Díaz Jorge E.
Published: December 2019

In this work, we investigate numerically a system of partial differential equations that describes the interactions between populations of predators and preys. The system considers the effects of anomalous diffusion and generalized Michaelis–Menten-type reactions. For the sake of generality, we consider an extended form of that system in various spatial dimensions and propose two finite-difference methods to approximate its solutions. Both methodologies are presented in alternative forms to facilitate their analyses and computer implementations. We show that both schemes are structure-preserving techniques, in the sense that they can keep the positive and bounded character of the computational approximations. This is in agreement with the relevant solutions of the original population model. Moreover, we prove rigorously that the schemes are consistent discretizations of the generalized continuous model and that they are stable and convergent. The methodologies were implemented efficiently using MATLAB. Some computer simulations are provided for illustration purposes. In particular, we use our schemes in the investigation of complex patterns in some two- and three-dimensional predator–prey systems with anomalous diffusion.
Multi-Start Local Search Algorithm for the Minimum Connected Dominating Set Problems
Authors: Li Ruizhi , Hu Shuli , Liu Huan , Li Ruiting , Ouyang Dantong , Yin Minghao
Published: December 2019

The minimum connected dominating set (MCDS) problem is a very significant NP-hard combinatorial optimization problem, and it has been used in many fields such as wireless sensor networks and ad hoc networks. In this paper, we propose a novel multi-start local search algorithm (MSLS) to tackle the minimum connected dominating set problem. Firstly, we present the fitness mechanism to design the vertex score mechanism so that our algorithm can jump out of the local optimum. Secondly, we use the configuration checking (CC) mechanism to avoid the cycling problem. Then, we propose the vertex flipping mechanism to change the vertex state by combing the CC mechanism with the vertex score mechanism. Finally, we propose a multi-start local search framework based on these mechanisms. We compare the algorithm MSLS with other compared algorithms on extensive instances. The results of experiment show that MSLS is superior to other algorithms in solution quality and time efficiency on most instances.
Ionizing Radiation for Preparation and Functionalization of Membranes and Their Biomedical and Environmental Applications
Authors: Casimiro Maria Helena , Ferreira Luis Mota , Leal João Paulo , Pereira Claudia Cristina Lage , Monteiro Bernardo
Published: December 2019

The use of ionizing radiation processing technologies has proven to be one of the most versatile ways to prepare a wide range of membranes with specific tailored functionalities, thus enabling them to be used in a variety of industrial, environmental, and biological applications. The general principle of this clean and environmental friendly technique is the use of various types of commercially available high-energy radiation sources, like 60Co, X-ray, and electron beam to initiate energy-controlled processes of free-radical polymerization or copolymerization, leading to the production of functionalized, flexible, structured membranes or to the incorporation of functional groups within a matrix composed by a low-cost polymer film. The present manuscript describes the state of the art of using ionizing radiation for the preparation and functionalization of polymer-based membranes for biomedical and environmental applications.
Asthma Case Cluster during Renovation of a Water-Damaged and Toxic Building
Authors: Hyvönen Saija , Syrjala Hannu
Published: December 2019

Background: An association between fungal exposure at work and asthma onset has been shown, but a causal relationship between them has not beTanle en established. Methods: The study describes an asthma cluster in workers in a building under renovation. Before renovation the work site had significant water damage, technical deficiencies, and ventilation problems. Worker protection was insufficient during renovation. In the building, toxicity was determined from dust as well as from cultured dust. Toxicity analysis was conducted in vitro using the boar spermatozoa motility assay. Results: During the 8-month renovation period, among 290 workers, 21 (7.2%) experienced new-onset asthma (9 women, 42.9%; 12 men, 57.1%; median age, 43 years (range, 30–60 years)). At the renovation site, they had been exposed to areas where remarkable toxicity was demonstrated in vitro. One year later, 13 (61.9%) of them still had moderate disease, and three (14.8%) had severe disease. Most patients had a poor response to inhaled corticosteroids. Conclusions: This study documents a clear temporal association between occupational exposure during renovation of a water-damaged building and a cluster of 21 new occupational asthma cases. In addition, dust and cultured dust from their work spaces showed remarkable toxicity based on inhibition of boar sperm motility in vitro.
Exceptional Preservation of Fungi as H2-Bearing Fluid Inclusions in an Early Quaternary Paleo-Hydrothermal System at Cape Vani, Milos, Greece
Authors: Ivarsson Magnus , Kilias Stephanos , Broman Curt , Neubeck Anna , Drake Henrik , Chi Fru Ernest , Bengtson Stefan , Naden Jonathan , Detsi Kleopatra , Whitehouse Martin
Published: December 2019

The production of H2 in hydrothermal systems and subsurface settings is almost exclusively assumed a result of abiotic processes, particularly serpentinization of ultramafic rocks. The origin of H2 in environments not hosted in ultramafic rocks is, as a rule, unjustifiably linked to abiotic processes. Additionally, multiple microbiological processes among both prokaryotes and eukaryotes are known to involve H2-production, of which anaerobic fungi have been put forward as a potential source of H2 in subsurface environments, which is still unconfirmed. Here, we report fungal remains exceptionally preserved as fluid inclusions in hydrothermal quartz from feeder quartz-barite veins from the Cape Vani Fe-Ba-Mn ore on the Greek island of Milos. The inclusions possess filamentous or near-spheroidal morphologies interpreted as remains of fungal hyphae and spores, respectively. They were characterized by microthermometry, Raman spectroscopy, and staining of exposed inclusions with WGA-FITC under fluorescence microscopy. The spheroidal aqueous inclusions interpreted as fungal spores are unique by their coating of Mn-oxide birnessite, and gas phase H2. A biological origin of the H2 resulting from anaerobic fungal respiration is suggested. We propose that biologically produced H2 by micro-eukaryotes is an unrecognized source of H2 in hydrothermal systems that may support communities of H2-dependent prokaryotes.
Micro-Raman Study of Thermal Transformations of Sulfide and Oxysalt Minerals Based on the Heat Induced by Laser
Authors: Xi Shichuan , Zhang Xin , Luan Zhendong , Du Zengfeng , Li Lianfu , Liang Zhengwei , Lian Chao , Yan Jun
Published: December 2019

The minerals in the hydrothermal and cold seep system form at different temperatures and show responses to the laser power to varying degrees. Here, we focus on the heat-induced by laser to study thermal transformations of the chalcopyrite, covellite, pyrite, barite, and aragonite based on Raman spectroscopy. Chalcopyrite mainly transforms into hematite, and covellite mainly transforms into chalcocite with the increase of laser power. Interestingly, comparing with the previous study, the pyrite can transform to the marcasite firstly, and form hematite finally. We also find that high-temperature opaque chalcopyrite is more likely to occur thermal transformations due to the smaller absolute energy difference (|ΔE1|) based on the frontier orbital theory. In contrast, the oxysalt minerals won’t transform into new components under high laser power. However, the structure of the barite has been destroyed by the high laser power, while the more transparent aragonite is not affected by the high laser power due to the laser penetrates through the transparent aragonite crystal and causes little heat absorption. Finally, we established the minimum laser power densities for thermal transformations of these minerals formed under different environments. The above study provides a simple way to study the thermal transformations of minerals by the local heat-induced by laser and also enlightens us to identify the minerals phases precisely.
Sal B Alleviates Myocardial Ischemic Injury by Inhibiting TLR4 and the Priming Phase of NLRP3 Inflammasome
Authors: Hu Yang , Li Qingju , Pan Yunzheng , Xu Li
Published: December 2019

Salvianolic acid B is one of the main water-soluble components of Salvia miltiorrhiza Bge. Many reports have shown that it has significant anti-myocardial ischemia effect. However, the underlying mechanism remains unclear. Our present study demonstrated that Sal B could alleviate myocardial ischemic injury by inhibiting the priming phase of NLRP3 inflammasome. In vivo, serum c-troponin I (cTn), lactate dehydrogenase (LDH) levels, the cardiac function and infract size were examined. We found that Sal B could notably reduce the myocardial ischemic injury caused by ligation of the left anterior descending coronary artery. In vitro, Sal B down-regulated the TLR4/NF-κB signaling cascades in lipopolysaccharide (LPS)-stimulated H9C2 cells. Furthermore, Sal B reduced the expression levels of IL-1β and NLRP3 inflammasome in a dose-dependent manner. In short, our study provided evidence that Sal B could attenuate myocardial ischemic injury via inhibition of TLR4/NF-κB/NLRP3 signaling pathway. And in an upstream level, MD-2 may be the potential target.
Conformational Investigations in Flexible Molecules Using Orientational NMR Constraints in Combination with 3J-Couplings and NOE Distances
Authors: Farès Christophe , Lingnau Julia B. , Wirtz Cornelia , Sternberg Ulrich
Published: December 2019

The downscaling of NMR tensorial interactions, such as dipolar couplings, from tens of kilohertz to a few hertz in low-order media is the result of dynamics spanning several orders of magnitudes, including vibrational modes (~ns-fs), whole-molecule reorientation (~ns) and higher barrier internal conformational exchange (<ms). In this work, we propose to employ these dynamically averaged interactions to drive an “alignment-tensor-free” molecular dynamic simulation with orientation constraints (MDOC) in order to efficiently access the conformational space sampled by flexible small molecules such as natural products. Key to this approach is the application of tensorial pseudo-force restraints which simultaneously guide the overall reorientation and conformational fluctuations based on defined memory function over the running trajectory. With the molecular mechanics force-field, which includes bond polarization theory (BPT), and complemented with other available NMR parameters such as NOEs and scalar J-couplings, MDOC efficiently arrives at dynamic ensembles that reproduce the entire NMR dataset with exquisite accuracy and theoretically reveal the systems conformational space and equilibrium. The method as well as its potential towards configurational elucidation is presented on diastereomeric pairs of flexible molecules: a small 1,4-diketone 1 with a single rotatable bond as well as a 24-ring macrolide related to the natural product mandelalide A 2.
Antiprotozoal Activity of Turkish Origanum onites Essential Oil and Its Components
Authors: Tasdemir Deniz , Kaiser Marcel , Demirci Betül , Demirci Fatih , Baser K. Hüsnü Can
Published: December 2019

Essential oil of Origanum species is well known for antimicrobial activity, but only a few have been evaluated in narrow spectrum antiprotozoal assays. Herein, we assessed the antiprotozoal potential of Turkish Origanum onites L. oil and its major constituents against a panel of parasitic protozoa. The essential oil was obtained by hydrodistillation from the dried herbal parts of O. onites and analyzed by Gas Chromatography-Flame Ionization Detector (GC-FID) and Gas Chromatography coupled with Mass Spectrometry (GC-MS). The in vitro activity of the oil and its major components were evaluated against Trypanosoma brucei rhodesiense, T. cruzi, Leishmania donovani, and Plasmodium falciparum. The main component of the oil was identified as carvacrol (70.6%), followed by linalool (9.7%), p-cymene (7%), γ-terpinene (2.1%), and thymol (1.8%). The oil showed significant in vitro activity against T. b. rhodesiense (IC50 180 ng/mL), and moderate antileishmanial and antiplasmodial effects, without toxicity to mammalian cells. Carvacrol, thymol, and 10 additional abundant oil constituents were tested against the same panel; carvacrol and thymol retained the oil’s in vitro antiparasitic potency. In the T. b. brucei mouse model, thymol, but not carvacrol, extended the mean survival of animals. This study indicates the potential of the essential oil of O. onites and its constituents in the treatment of protozoal infections.
Exploring the Self-Assembled Tacticity in Aurophilic Polymeric Arrangements of Diphosphanegold(I) Fluorothiolates
Authors: Moreno-Alcántar Guillermo , Salazar Laura , Romo-Islas Guillermo , Flores-Álamo Marcos , Torrens Hugo
Published: December 2019

Despite the recurrence of aurophilic interactions in the solid-state structures of gold(I) compounds, its rational control, modulation, and application in the generation of functional supramolecular structures is an area that requires further development. The ligand effects over the aurophilic-based supramolecular structures need to be better understood. This paper presents the supramolecular structural diversity of a series of new 1,3-bis(diphenylphosphane)propane (dppp) gold(I) fluorinated thiolates with the general formula [Au2(SRF)2(μ-dppp)] (SRF = SC6F5 (1); SC6HF4-4 (2); SC6H3(CF3)2-3,5 (3); SC6H4CF3-2 (4); SC6H4CF3-4 (5); SC6H3F2-3,4 (6); SC6H3F2-3,5 (7); SC6H4F-2 (8); SC6H4F-3 (9); SC6H4F-4 (10)). These compounds were synthesized and characterized, and six of their solid-state crystalline structures were determined using single-crystal X-ray diffraction. In the crystalline arrangement, they form aurophilic-bridged polymers. In these systems, the changes in the fluorination patterns of the thiolate ligands tune the aurophilic-induced self-assembly of the compounds causing tacticity and chiral differentiation of the monomers. This is an example of the use of ligand effects on the tune of the supramolecular association of gold complexes.
Reinforcing Mechanism of Reduced Graphene Oxide on Flexural Strength of Geopolymers: A Synergetic Analysis of Hydration and Chemical Composition
Authors: Long Wu-Jian , Ye Tao-Hua , Luo Qi-Ling , Wang Yaocheng , Mei Liu
Published: December 2019

With the development of nanotechnology, reduced graphene oxide (rGO) has been used to improve the flexural strength of geopolymers. However, the reinforcing mechanism of rGO nanosheets on the flexural strength of geopolymers remains unclear. Here, this reinforcing mechanism was investigated from the perspectives of hydration and chemical composition. The effect of the reduction degree on rGO-reinforced geopolymers was also studied using isothermal calorimetry (IC), X-ray diffraction (XRD), and nuclear magnetic resonance (NMR) tests. Results show that the hydration degree and flexural strength of geopolymers effectively increase due to rGO addition. After alkali reduction at a temperature of 60 °C, rGO nanosheets have maximum reinforcement on the flexural strength of geopolymers with an increment of 51.2%. It is attributed to the promotion of slag hydration, as well as the simultaneous formation of calcium silicate hydrate with low Ca/Si ratio (C-S-H(I)) and calcium aluminosilicate hydrate (C-A-S-H) phases due to the inhibiting effect of rGO nanosheets on Al substitution on the end-of-chain silicates of C-S-H and C-A-S-H gels. In addition, different reduction degrees have almost no effect on the chemical composition of rGO-reinforced geopolymers, while excessive reduction impairs the improving effect of rGO nanosheets on the hydration process and flexural strength of geopolymers due to significant structural defects.
Lotus Root-Like Nitrogen-Doped Carbon Nanofiber Structure Assembled with VN Catalysts as a Multifunctional Host for Superior Lithium–Sulfur Batteries
Authors: Wei Benben , Shang Chaoqun , Pan Xiaoying , Chen Zhihong , Shui Lingling , Wang Xin , Zhou Guofu
Published: December 2019

Lithium–sulfur batteries (LSBs) are regarded as one of the most promising energy-recycling storage systems due to their high energy density (up to 2600 Wh kg−1), high theoretical specific capacity (as much as 1672 mAh g−1), environmental friendliness, and low cost. Originating from the complicated redox of lithium polysulfide intermediates, Li–S batteries suffer from several problems, restricting their application and commercialization. Such problems include the shuttle effect of polysulfides (Li2Sx (2 < x ≤ 8)), low electronic conductivity of S/Li2S/Li2S2, and large volumetric expansion of S upon lithiation. In this study, a lotus root-like nitrogen-doped carbon nanofiber (NCNF) structure, assembled with vanadium nitride (VN) catalysts, was fabricated as a 3D freestanding current collector for high performance LSBs. The lotus root-like NCNF structure, which had a multichannel porous nanostructure, was able to provide excellent (ionically/electronically) conductive networks, which promoted ion transport and physical confinement of lithium polysulfides. Further, the structure provided good electrolyte penetration, thereby enhancing the interface contact with active S. VN, with its narrow resolved band gap, showed high electrical conductivity, high catalytic effect and polar chemical adsorption of lithium polysulfides, which is ideal for accelerating the reversible redox kinetics of intermediate polysulfides to improve the utilization of S. Tests showed that the VN-decorated multichannel porous carbon nanofiber structure retained a high specific capacity of 1325 mAh g−1 after 100 cycles at 0.1 C, with a low capacity decay of 0.05% per cycle, and demonstrated excellent rate capability.
3D Printing of UV-Curable Polyurethane Incorporated with Surface-Grafted Nanocellulose
Authors: Mohan Denesh , Sajab Mohd Shaiful , Kaco Hatika , Bakarudin Saiful Bahari , Mohamed Noor An’amt
Published: December 2019

The recognition of nanocellulose has been prominent in recent years as prospect materials, yet the ineffectiveness of nanocellulose to disperse in an organic solvent has restricted its utilization, especially as a reinforcement in polymer nanocomposite. In this study, cellulose has been isolated and defibrillated as cellulose nanofibrils (CNF) from oil palm empty fruit bunch (EFB) fibers. Subsequently, to enhance its compatibility with UV-curable polyurethane (PU)-based resin, the surface hydrophilicity of CNF has been tailored with polyethylene glycol (PEG), as well as reduced graphene oxide (rGO). The dispersibility of reinforced modified CNF in UV-curable PU was examined through the transmittance interruption of resin, chemical, and mechanical properties of the composite printed using the stereolithographic technique. Evidently, the enhanced compatibility of modified CNF and UV-curable PU was shown to improve the tensile strength and hardness of the composites by 37% and 129%, respectively.
Terahertz Dielectric Spectroscopic Analysis of Polypropylene Aging Caused by Exposure to Ultraviolet Radiation
Authors: Chang Tianying , Zhang Xiansheng , Cui Hong-Liang
Published: December 2019

Terahertz dielectric spectroscopy is shown to be an effective tool for bench-marking ultraviolet aging of polypropylene. In this, thin-film polypropylene samples exposed to standard artificial ultraviolet radiation in accelerated aging from 1 day to 30 days are closely monitored by a terahertz time-domain spectroscopy system and analyzed using an effective data processing method. It is found that the terahertz absorption of the polypropylene samples is generally weak and the terahertz dielectric constant varies slightly though discernibly during the aging process, with the refractive index decreasing slightly with increasing length of ultraviolet exposure. Nonetheless, the rate of variation of the polypropylene refractive index with increasing terahertz frequency exhibits a drastic inflection around the 15-days aging point and the rate changes suddenly from positive value to negative value. Based on this prominent and consistent THz dielectric spectroscopic feature of the aging process, an efficient judging criterion is established to distinguish the early-term, mid-term, and late-term phases as well as the degree of polypropylene ultraviolet aging, corresponding to the fundamental transformation of the polymer material from a nonpolar to a polar substance at a critical level of oxidation induced by ultraviolet radiation.
Application of a Zwitterionic Hydrophobic Associating Polymer with High Salt and Heat Tolerance in Brine-Based Fracturing Fluid
Authors: Tian Jizhen , Mao Jincheng , Zhang Wenlong , Yang Xiaojiang , Lin Chong , Cun Meng , Mao Jinhua , Zhao Jinzhou
Published: December 2019

ZID16PM, a zwitterionic hydrophobic associating polymer, has equivalent positive and negative charges and some hydrophobic monomers with twin-tailed long hydrophobic chains. It exhibits a great heat resistance and salt tolerance to the common salt in formation brine (MgCl2, CaCl2, NaCl, and KCl), which is attributed to its anti-polyelectrolyte effect and strong association force. High-salinity water (seawater or formation water) can be prepared as a fracturing fluid directly. In this paper, the formation water of the West Sichuan Gas Field is directly prepared into fracturing fluid with a concentration of 0.3% ZID16PM (Fluid-1), and the seawater of the Gulf of Mexico is directly prepared into fracturing fluid with a concentration of 0.3% ZID16PM (Fluid-2). Finally, rheological measurements, proppant suspension tests, and core matrix permeability damage rate tests for the Fluid-1 and Fluid-2 are conducted. Results show that after 120 min of shearing at 140 and 160 °C, respectively, the viscosity of Fluid-1 remains in the range of 50–85 mPa·s, and the viscosity of Fluid-2 remains in the range of 60–95 mPa·s. And the wastewater produced by an oilfield in Shaanxi, Xinjiang, and Jiangsu are also prepared into fracturing fluids with a concentration of 0.3% ZID16PM, the viscosity of these fracturing fluids can remain 32, 42, and 45 mPa·s, respectively, after 120 min of shearing at 160 °C. All results demonstrate that the polymer ZID16PM displays prominent performance in fracturing fluids.
Study of the Affinity Law of Energy and Cavitation Characteristics in Emergency Drainage Pumps at Different Rotating Speeds
Authors: Cao Weidong , Mao Jiayu
Published: December 2019

The affinity law is widely used in pump design and experiments. The applicability of the affinity law in an emergency drainage pump at different rotating speeds was studied. Experiments and numerical simulation through ANSYS CFX (Computational Fluid Dynamics X) 15.0 software were used to research the affinity law characteristics. Results show that the simulation of characteristics is basically consistent with the experimental curves. In small flow rate conditions, due to the existence of obvious differential pressure between the pressure side and the suction side in the impeller blade tip area, the leakage flow occurs at the tip clearance, which collides with the main stream at the inlet and generates vortices at the leading edge of the impeller. The tip leakage flows of the pump at four different rotating speeds were compared, and it was found that the tip leakage increased with increasing rotation speed, and at the same rotation speed, the tip leakage flow was large in the small flow rate condition, which led to the simulation value of the characteristics being greater than the scaling value. As the flow rate increased, the anti-cavitation performance of the pump became worse and the hydraulic loss was larger, so the pump’s performance curve deviated from the scaling curve.
Human–Robot Collaboration in Manufacturing Applications: A Review
Authors: Matheson Eloise , Minto Riccardo , Zampieri Emanuele G. G. , Faccio Maurizio , Rosati Giulio
Published: December 2019

This paper provides an overview of collaborative robotics towards manufacturing applications. Over the last decade, the market has seen the introduction of a new category of robots—collaborative robots (or “cobots”)—designed to physically interact with humans in a shared environment, without the typical barriers or protective cages used in traditional robotics systems. Their potential is undisputed, especially regarding their flexible ability to make simple, quick, and cheap layout changes; however, it is necessary to have adequate knowledge of their correct uses and characteristics to obtain the advantages of this form of robotics, which can be a barrier for industry uptake. The paper starts with an introduction of human–robot collaboration, presenting the related standards and modes of operation. An extensive literature review of works published in this area is undertaken, with particular attention to the main industrial cases of application. The paper concludes with an analysis of the future trends in human–robot collaboration as determined by the authors.
When Sensor-Cloud Meets Mobile Edge Computing
Authors: Wang Tian , Lu Yucheng , Cao Zhihan , Shu Lei , Zheng Xi , Liu Anfeng , Xie Mande
Published: December 2019

Sensor-clouds are a combination of wireless sensor networks (WSNs) and cloud computing. The emergence of sensor-clouds has greatly enhanced the computing power and storage capacity of traditional WSNs via exploiting the advantages of cloud computing in resource utilization. However, there are still many problems to be solved in sensor-clouds, such as the limitations of WSNs in terms of communication and energy, the high latency, and the security and privacy issues due to applying a cloud platform as the data processing and control center. In recent years, mobile edge computing has received increasing attention from industry and academia. The core of mobile edge computing is to migrate some or all of the computing tasks of the original cloud computing center to the vicinity of the data source, which gives mobile edge computing great potential in solving the shortcomings of sensor-clouds. In this paper, the latest research status of sensor-clouds is briefly analyzed and the characteristics of the existing sensor-clouds are summarized. After that we discuss the issues of sensor-clouds and propose some applications, especially a trust evaluation mechanism and trustworthy data collection which use mobile edge computing to solve the problems in sensor-clouds. Finally, we discuss research challenges and future research directions in leveraging mobile edge computing for sensor-clouds.
Lower Body Kinematics Monitoring in Running Using Fabric-Based Wearable Sensors and Deep Convolutional Neural Networks
Authors: Gholami Mohsen , Rezaei Ahmad , Cuthbert Tyler J. , Napier Christopher , Menon Carlo
Published: December 2019

Continuous kinematic monitoring of runners is crucial to inform runners of inappropriate running habits. Motion capture systems are the gold standard for gait analysis, but they are spatially limited to laboratories. Recently, wearable sensors have gained attention as an unobtrusive method to analyze performance metrics and the health conditions of runners. In this study, we developed a system capable of estimating joint angles in sagittal, frontal, and transverse planes during running. A prototype with fiber strain sensors was fabricated. The positions of the sensors on the pelvis were optimized using a genetic algorithm. A cohort of ten people completed 15 min of running at five different speeds for gait analysis by our prototype device. The joint angles were estimated by a deep convolutional neural network in inter- and intra-participant scenarios. In intra-participant tests, root mean square error (RMSE) and normalized root mean square error (NRMSE) of less than 2.2° and 5.3%, respectively, were obtained for hip, knee, and ankle joints in sagittal, frontal, and transverse planes. The RMSE and NRMSE in inter-participant tests were less than 6.4° and 10%, respectively, in the sagittal plane. The accuracy of this device and methodology could yield potential applications as a soft wearable device for gait monitoring of runners.
A Survey on Detection, Tracking and Identification in Radio Frequency-Based Device-Free Localization
Authors: Denis Stijn , Berkvens Rafael , Weyn Maarten
Published: December 2019

The requirement of active localization techniques to attach a hardware device to the targets that need to be located can be difficult or even impossible for certain applications. For this reason, there has been an increasing interest in tagless or device-free localization (DFL) approaches. In particular, the research domain of RF-based device-free localization has been steadily evolving since its inception slightly over a decade ago. Many novel techniques have been developed regarding the three core aspects of DFL: detection, tracking, and identification. The increasing use of channel state information (CSI) has contributed considerably to these developments. In particular, the progress it enabled regarding the exceptionally difficult `identification problem’ has been highly impressive. In this survey, we provide a comprehensive overview of this evolutionary process, describe essential DFL concepts and highlight several key techniques whose creation marked important milestones within this field of research. We do so in a structured manner in which each technique is categorized according to the DFL core aspect it emphasizes most. Additionally, we discuss current blocking issues within the state-of-the-art and suggest multiple high-level research directions which will aid in the search towards eventual solutions.
A Low-Complexity Compressed Sensing Reconstruction Method for Heart Signal Biometric Recognition
Authors: Xiao Jian , Hu Fang , Shao Qiang , Li Sizhuo
Published: December 2019

Biometric systems allow recognition and verification of an individual through his or her physiological or behavioral characteristics. It is a growing field of research due to the increasing demand for secure and trustworthy authentication systems. Compressed sensing is a data compression acquisition method that has been proposed in recent years. The sampling and compression of data is completed synchronously, avoiding waste of resources and meeting the requirements of small size and limited power consumption of wearable portable devices. In this work, a compression reconstruction method based on compression sensing was studied using bioelectric signals, which aimed to increase the limited resources of portable remote bioelectric signal recognition equipment. Using electrocardiograms (ECGs) and photoplethysmograms (PPGs) of heart signals as research data, an improved segmented weak orthogonal matching pursuit (OMP) algorithm was developed to compress and reconstruct the signals. Finally, feature values were extracted from the reconstructed signals for identification and analysis. The accuracy of the proposed method and the practicability of compression sensing in cardiac signal identification were verified. Experiments showed that the reconstructed ECG and PPG signal recognition rates were 95.65% and 91.31%, respectively, and that the residual value was less than 0.05 mV, which indicates that the proposed method can be effectively used for two bioelectric signal compression reconstructions.
Chrysoviruses Inhabited Symbiotic Fungi of Lichens
Authors: Petrzik Karel , Koloniuk Igor , Sehadová Hana , Sarkisova Tatiana
Published: December 2019

A lichen body is formed most often from green alga cells trapped in a net of ascomycetous fungi and accompanied by endolichenic or parasitic fungi, other algae, and symbiotic or free-living bacteria. The lichen’s microcosmos is inhabited by mites, insects, and other animals for which the lichen is a source of food or a place to live. Novel, four-segmented dsRNA viruses were detected in saxicolous Chrysothrix chlorina and Lepraria incana lichens. Comparison of encoded genome proteins revealed classification of the viruses to the genus Alphachrysovirus and a relationship to chrysoviruses from filamentous ascomycetous fungi. We propose the names Chrysothrix chrysovirus 1 (CcCV1) and Lepraria chrysovirus 1 (LiCV1) as acronyms for these viruses. Surprisingly, observation of Chrysothrix chlorina hybridization with fluorescent-labelled virus probe by confocal microscope revealed that the CcCV1 virus is not present in the lichen body-forming fungus but in accompanying endolichenic Penicillium citreosulfuratum fungus. These are the first descriptions of mycoviruses from a lichen environment.
An MVA Vector Expressing HIV-1 Envelope under the Control of a Potent Vaccinia Virus Promoter as a Promising Strategy in HIV/AIDS Vaccine Design
Authors: Pérez Patricia , Marín María Q. , Lázaro-Frías Adrián , Sorzano Carlos Óscar S. , Di Pilato Mauro , Gómez Carmen E. , Esteban Mariano , García-Arriaza Juan
Published: December 2019

Highly attenuated poxviral vectors, such as modified vaccinia virus ankara (MVA), are promising vaccine candidates against several infectious diseases. One of the approaches developed to enhance the immunogenicity of poxvirus vectors is increasing the promoter strength and accelerating during infection production levels of heterologous antigens. Here, we have generated and characterized the biology and immunogenicity of an optimized MVA-based vaccine candidate against HIV/AIDS expressing HIV-1 clade B gp120 protein under the control of a novel synthetic late/early optimized (LEO) promoter (LEO160 promoter; with a spacer length of 160 nucleotides), termed MVA-LEO160-gp120. In infected cells, MVA-LEO160-gp120 significantly increased the expression levels of HIV-1 gp120 mRNA and protein, compared to the clinical vaccine MVA-B vector expressing HIV-1 gp120 under the control of the commonly used synthetic early/late promoter. When mice were immunized with a heterologous DNA-prime/MVA-boost protocol, the immunization group DNA-gp120/MVA-LEO160-gp120 induced an enhancement in the magnitude of gp120-specific CD4+ and CD8+ T-cell responses, compared to DNA-gp120/MVA-B; with most of the responses being mediated by the CD8+ T-cell compartment, with a T effector memory phenotype. DNA-gp120/MVA-LEO160-gp120 also elicited a trend to a higher magnitude of gp120-specific CD4+ T follicular helper cells, and modest enhanced levels of antibodies against HIV-1 gp120. These findings revealed that this new optimized vaccinia virus promoter could be considered a promising strategy in HIV/AIDS vaccine design, confirming the importance of early expression of heterologous antigen and its impact on the antigen-specific immunogenicity elicited by poxvirus-based vectors.
Effects of Roughness Coefficients and Complex Hillslope Morphology on Runoff Variables under Laboratory Conditions
Authors: Meshkat Masoud , Amanian Nosratollah , Talebi Ali , Kiani-Harchegani Mahboobeh , Rodrigo-Comino Jesús
Published: December 2019

The geometry of hillslopes (plan and profile) affects soil erosion under rainfall-runoff processes. This issue comprises of several factors, which must be identified and assessed if efficient control measures are to be designed. The main aim of the current research was to investigate the impact of surface Roughness Coefficients (RCs) and Complex Hillslopes (CHs) on runoff variables viz. time of generation, time of concentration, and peak discharge value. A total of 81 experiments were conducted with a rainfall intensity of 7 L min−1 on three types of soils with different RCs (i.e., low = 0.015, medium = 0.016, and high = 0.018) and CHs (i.e., profile curvature and plan shape). An inclination of 20% was used for three replications. The results indicate a significant difference (p-value ≤ 0.001) in the above-mentioned runoff variables under different RCs and CHs. Our investigation of the combined effects of RCs and CHs on the runoff variables shows that the plan and profile impacts are consistent with a variation in RC. This can implicate that at low RC, the effect of the plan shape (i.e., convergent) on runoff variables increases but at high RC, the impact of the profile curvature overcomes the plan shapes and the profile curvature’s changes become the criteria for changing the behavior of the runoff variables. The lowest mean values of runoff generation and time of concentration were obtained in the convex-convergent and the convex-divergent at 1.15 min and 2.68 min, respectively, for the soil with an RC of 0.015. The highest mean of peak discharge was obtained in the concave-divergent CH in the soil with an RC of 0.018. We conclude that these results can be useful in order to design planned soil erosion control measures where the soil roughness and slope morphology play a key role in activating runoff generation.
Influence of Changes of Catchment Permeability and Frequency of Rainfall on Critical Storm Duration in an Urbanized Catchment—A Case Study, Cracow, Poland
Authors: Wałęga Andrzej , Radecki-Pawlik Artur , Cupak Agnieszka , Hathaway Jon , Pukowiec Michał
Published: December 2019

The increase of impermeable areas in a catchment is known to elevate flood risk. To adequately understand and plan for these risks, changes in the basin water cycle must be quantified as imperviousness increases, requiring the use of hydrological modeling to obtain design runoff volumes and peak flow rates. A key stage of modeling is adopting the structure of the model and estimating its parameters. Due to the fact that most impervious basins are uncontrolled, hydrological models that do not require parameter calibration are advantageous. At the same time, it should be remembered that these models are sensitive to the values of assumed parameters. The purpose of this work is to determine the effect of catchment impermeability on the flow variability in the Sudół Dominikański stream in Cracow, Poland, and assess the influence of the frequency of rainfall on values of time of concentration (here it is meant as critical storm duration). The major finding in this work is that the critical storm duration for all different scenarios of catchment imperviousness depends on the rainfall exceedance probability. In the case of rainfall probability lower than 5.0%, the critical storm duration was equal to 2 h, for higher probabilities (p ≥ 50%) it was equal to 24 h. Simulations showed that the increase of impermeable areas caused peak time abbreviation. In the case of rainfall with exceedance probability p = 1.0% and critical storm duration Dkr = 2 h, the peak time decreased about 12.5% and for impermeable areas increased from 22.01 to 44.95%.
FAKTOR - FAKTOR YANG MEMPENGARUHI KEPUTUSAN PEMBELIAN DAN DAMPAKNYA PADA KELANGSUNGAN USAHA MIKRO KECIL MENENGAH PADA USAHA FOTOCOPY SEKECAMATAN RENGAT
Authors: Hermanto Hermanto , Corrina Fatti , Supriyadi Agus
Published: December 2019

Penelitian ini dilakukan pada Usaha Mikro, Kecil dan Menengah yang bergerak di usaha Fotocopy pada Kecamatan Rengat. Sampel dalam penelitian ini adalah konsumen yang berbelanja di Fotocopy yang ada dikecamatan Rengat sebanyak 270 Sampel. Jenis data yang digunakan dalam penelitian ini adalah data primer yaitu berupa data kuantitatif yang dilakukan dengan menyebarkan kuisioner kekonsumen yang berbelanja. Alat analisis yang penulis gunakan ialah Analisis Regresi Linear Berganda dengan pendekatan kuantitatif dengan bantuan Software SPSS Versi 21. Hasil penelitian dapat disimpulkan bahwa : (1) Produk secara parsial berpengaruh signifikan terhadap Keputusan Pembelian pada usaha Fotocopy seKecamatan Rengat. (2) Harga secara parsial berpengaruh signifikan terhadap Keputusan Pembelian pada usaha Fotocopy seKecamatan Rengat. (3) Lokasi secara parsial berpengaruh signifikan terhadap Keputusan Pembelian pada usaha Fotocopy seKecamatan Rengat. (4) Promosi secara parsial berpengaruh signifikan terhadap Keputusan Pembelian pada usaha Fotocopy seKecamatan Rengat. (5) Produk, Harga, Lokasi dan Promosi secara simultan berpengaruh signifikan terhadap Keputusan Pembelian pada usaha Fotocopy seKecamatan Rengat
Les Celtibères : archéologie et culture
Authors: Lorrio Alberto J.
Published: December 2019

Celtiberians : archeology and culture

The Celtiberians are one of the most important Celtic peoples of the Iberian Peninsula. The archeological record, the historical sources and the linguistic evidence enable the Celtiberians to be located in the highlands of the Eastern Meseta, the Iberian System and the lands of the right bank of the Middle Ebro Valley. An analysis of the settlements, the cemeteries, the weapons and other elements of the material culture, has made possible to establish for the first time a cultural sequence of the Celtiberian world, from the 8th-7th century B.C. to the Roman Conquest.
Praeindogermanica
Authors: Hubschmid Johannes
Published: December 2019

Le radical pré-indoeuropéen *pītt- vit aussi dans le fr. piton 'clou à vis’, dans l’esp. pitón 'corne qui vient de naître à la tête d’un animal’ et dans beaucoup de noms de lieux espagnols et portugais (Pitellas, Pito, etc.). L’a. prov. pitar 'becqueter’ est de la même famille et suppose un radical *pītt-bec (pointu)’.

A côté de *pītt-, on doit supposer une variante *pitt-ou pett- : gasc. petarro 'colline, montée très raide’, basque petarra 'le raidillon, la côte très rapide’ ; galic. petouco 'colline rocheuse’ ; peteiro 'bec’ ; d’où les noms de lieux Peteiro, etc. Le galic. peta désigne une sorte de houe pointue, le léon. pétanas les parties saillantes de l’outre qui correspondent aux pattes.

En Italie, nous trouvons, dans la région de Lucques, pitone 'grosse pierre’ (aussi dans des noms de lieu). La zone du prov. pitar se prolonge dans le gen. et corse pitá 'becqueter’. Le substantif correspondant vit dans l’Italie méridionale. Les noms de lieu du type Pittula s’expliquent, probablement, par le bas-lat. pittulus 'petit’. Ce mot, comme le fr. petit et sa famille, est certainement à rattacher au radical *pitt- 'aigu, pointu’. D’autre part, le dérivé (Amalfi) pitigno 'rocher, précipice’ est un témoin précieux de la base *pitt- avec valeur oronymique dans l’Italie méridionale.

Les noms de lieu Pedena de l’Italie septentrionale et Pedenal des Grisons pourraient contenir le même radical sans consonne géminée. Toutefois, nous trouvons dans les Grisons et plus à l’est des mots qui supposent une base * pitta 'gâteau, galette’, rarement 'pain (de forme longue)’. Cette famille est répandue jusque dans les Balkans ; elle réapparaît dans le galic. petada. Elle ne peut être séparée du gr. πιττάχιον 'feuille de tablette à écrire ; emplâtre’, lui-même emprunté d’un parler du nord des Balkans.

L’étude du dérivé * pīttjo-(> engad. piz 'pointe, pointe de montagne’) et des bases voisines *pīkk- (> fr. pic ; esp. pico 'bec’) et *bīkk-/*bikk- (port. bico, it. becco, fr. bec, gaul. beccus (> prov. bçc) confirme les explications données pour la base * pītt-/* pitt- en ce qui concerne le développement de sens. En effet, les représentants de * pīttjo-, *pīkk-, etc., ne désignent pas seulement des objets pointus, des cimes de montagne, mais aussi des objets petits : vieux sarde pithinnu 'petit’ ; it. piccolo ; esp. pequeño ; it. becc. L’it. mérid. pizza, le frioul. picót et le galic. bica désignent des galettes ou des pains.

Le gr. πέτρα 'cime rocheuse’ pourrait être une variante prégrecque du basque petarra. Par contre, les mots caucasiques allégués par M. Bouda, pat 'côte’, sont d’origine différente.
Aort Kapak Kalsifikasyon Derecesi ile Epikardiyal Yağ Dokusu Kalınlığı İlişkisi
Authors: ZUNGUR Mustafa
Published: December 2019

Amaç: Artmış epikardiyal yağ dokusu kalınlığı ,
koroner arter hastalığının varlığı ve yaygınlığı, ateroskleroz,hipertansiyon,
insülin direnci ,diabetes mellitus ,metabolik sendrom gibi hastalıklar ve bunların enflamatuar süreçleri ile ilişkili bulunmuştur. Bu çalışmada epikardiyal yağ dokusu kalınlığı ile ateroskleroz ve birçok hastalıkla birlikte gözlenen aort kapak kalsifikasyonu arasındaki ilişkiyi değerlendirmeyi amaçladık. Materyal ve Metod: Çalışmaya Haziran 2015-Nisan 2018 arasında kardiyoloji polikliniğine başvuran (59 kadın, 45 erkek ,ortalama yaş: 78.0 ± 7.3 yıl) 114 hasta alındı. Epikardiyal yağ dokusu kalınlığı ölçümü iki boyutlu ekokardiyografik yöntemle diastol sonunda yağ dokusu dansitesiyle uyumlu bölgeden yapıldı Aort kapak kalsifikasyon derecelendirmesi ECG-gated 128-MD bilgisayarlı tomografi  cihazı ile yapıldı.Aort kapak kalsifikasyonu  grade 1(kalsifikasyon saptanmadı) , grade 2 (hafif kalsifikasyon,küçük izole noktalanmalar),grade 3 (orta düzeyde kalsifikasyon,çoklu geniş noktalanmalar) ve grade 4 (ağır kalsifikasyon,bütün küspisleri içeren yaygın kalsifikasyon) şeklinde değerlendirildi.Çalışmamıza alınan hastalar aort kapak kalsifikasyon derecelendirmesine göre 3 grupta yer alıyordu.Bulgular: Aort kapak kalsifikasyon
derecelendirmesine göre ayrılan gruplar arasında koroner arter hastalığı,
hipertansiyon, diabetes mellitus ve hiperlipidemi açısından fark saptanmadı.
Epikardiyal yağ dokusu kalınlığı ; aort kapak kalsifikasyon derecelendirmesine
göre Grade 4  de yer alan hastalarda  Grade 2,3 
dekilere  göre    daha yüksek saptandı.

Sonuç: Hastalarda 
epikardiyal yağ dokusu kalınlığı ölçümü, ekokardiyografik değerlendirme
sırasında aort kapak kalsifikasyonu ve derecesi hakkında da   bilgi verebilecek kullanışlı bir parametre
olabileceğini düşündürmüştür.