bluuebunny/crossref_metadata_2025 huggingface dataset:
Dual solutions of nanomaterial flow comprising titanium alloy (Ti6Al4V) suspended in Williamson fluid through a thin moving needle with nonlinear thermal radiation: stability scrutinization
Authors: Khan Umair , Zaib A. , Khan Ilyas , Nisar Kottakkaran Sooppy
Published: December 2020

Titanium alloy nanoparticle has a variety of applications in the manufacturing of soap and plastic, microsensors, aerospace design material, nano-wires, optical filters, implantation of surgical, and many biological treatments. Therefore, this research article discussed the influence of nonlinear radiation on magneto Williamson fluid involving titanium alloy particles through a thin needle. The arising system of partial differential equations is exercised by the similarity transformations to get the dimensional form of ordinary differential equations. The dual nature of solutions is obtained by implementing bvp4c. The study of stability has been carried out to check which of the results are physically applicable and stable. Influences of pertinent constraints on the flow field are discussed with the help of graphical representations and the method validation is shown in Table 1. The results imply that more than one result is established when the moving needle and the free-stream travel in the reverse directions. Moreover, the magnetic parameter accelerates the severance of boundary-layer flow, while the separation delays in the absence of the nanoparticle. The velocity gradient of nanofluid decays owing to the Williamson parameter in both branches of the outcome, while the temperature shrinks in the first or upper branch solution (stable one) and uplifts in the second or lower branch solution (unstable one). The size of the needle decreases the velocity in the upper solution and accelerates in the lower solution. The patterns of streamlines are more complicated due to the reverse direction of the free stream and thin needle.
Nutraceutical supplements in management of pain and disability in osteoarthritis: a systematic review and meta-analysis of randomized clinical trials
Authors: Aghamohammadi Dawood , Dolatkhah Neda , Bakhtiari Fahimeh , Eslamian Fariba , Hashemian Maryam
Published: December 2020

This study designed to evaluate the effect of nutraceutical supplementation on pain intensity and physical function in patients with knee/hip OA. The MEDLINE, Web of Science, Cochrane Library, Scopus, EMBASE, Google Scholar, Science direct, and ProQuest in addition to SID, Magiran, and Iranmedex were searched up to March 2020. Records (n = 465) were screened via the PICOS criteria: participants were patients with hip or knee OA; intervention was different nutritional supplements; comparator was any comparator; the outcome was pain intensity (Visual analogue scale [VAS]) and physical function (Western Ontario and McMaster Universities Arthritis [WOMAC] index); study type was randomized controlled trials. The random effects model was used to pool the calculated effect sizes. The standardized mean difference (SMD) of the outcome changes was considered as the effect size. The random effects model was used to combine the effect sizes. Heterogeneity between studies was assessed by Cochran's (Q) and I2 statistics. A total of 42 RCTs were involved in the meta-analysis. Nutritional supplementation were found to improve total WOMAC index (SMD = − 0.23, 95% CI − 0.37 to − 0.08), WOMAC pain (SMD = − 0.36, 95% CI − 0.62 to − 0.10) and WOMAC stiffness (SMD = − 0.47, 95% CI − 0.71 to − 0.23) subscales and VAS (SMD = − 0.79, 95% CI − 1.05 to − 0.05). Results of subgroup analysis according to the supplementation duration showed that the pooled effect size in studies with < 10 months, 10–20 months and > 20 months supplementation duration were 0.05, 0.27, and 0.36, respectively for WOMAC total score, 0.14, 0.55 and 0.05, respectively for WOAMC pain subscale, 0.59, 0.47 and 0.41, respectively for WOMAC stiffness subscale, 0.05, 0.57 and 0.53, respectively for WOMAC physical function subscale and 0.65, 0.99 and 0.12, respectively for VAS pain. The result suggested that nutraceutical supplementation of patients with knee/hip OA may lead to an improvement in pain intensity and physical function.
Understanding how best to engage recreationists in biosecurity to reduce the impacts of tree diseases: a review
Authors: Hall Clare , Marzano Mariella , O'Brien Liz
Published: December 2020

Pests and diseases introduced from other countries are known to pose a threat to trees, woods and forests in many locations throughout the world. Once introduced they can be spread inadvertently by countryside visitors hiking, biking or riding along paths and trails through wooded areas. Engaging and communicating with these groups of countryside users to encourage and facilitate positive biosecurity behaviours is crucial for the future resilience of trees, woods and forests. This review draws on literature outlining principles for stakeholder engagement in forestry as well as evaluations of biosecurity campaigns from around the world. Key points are briefly presented for communicators aiming to encourage better biosecurity in the countryside. These include, the need to design campaigns based on the values and motivations of recreationists, using trusted information sources and understanding the importance of combining information with facilities so as to reduce the cost (in terms of effort and inconvenience) to hikers and other countryside users.
The zoonotic potential of bat-borne coronaviruses
Authors: Ravelomanantsoa Ny Anjara Fifi , Guth Sarah , Andrianiaina Angelo , Andry Santino , Gentles Anecia , Ranaivoson Hafaliana Christian , Brook Cara E.
Published: December 2020

Seven zoonoses — human infections of animal origin — have emerged from the Coronaviridae family in the past century, including three viruses responsible for significant human mortality (SARS-CoV, MERS-CoV, and SARS-CoV-2) in the past twenty years alone. These three viruses, in addition to two older CoV zoonoses (HCoV-229E and HCoV-NL63) are believed to be originally derived from wild bat reservoir species. We review the molecular biology of the bat-derived Alpha- and Betacoronavirus genera, highlighting features that contribute to their potential for cross-species emergence, including the use of well-conserved mammalian host cell machinery for cell entry and a unique capacity for adaptation to novel host environments after host switching. The adaptive capacity of coronaviruses largely results from their large genomes, which reduce the risk of deleterious mutational errors and facilitate range-expanding recombination events by offering heightened redundancy in essential genetic material. Large CoV genomes are made possible by the unique proofreading capacity encoded for their RNA-dependent polymerase. We find that bat-borne SARS-related coronaviruses in the subgenus Sarbecovirus, the source clade for SARS-CoV and SARS-CoV-2, present a particularly poignant pandemic threat, due to the extraordinary viral genetic diversity represented among several sympatric species of their horseshoe bat hosts. To date, Sarbecovirus surveillance has been almost entirely restricted to China. More vigorous field research efforts tracking the circulation of Sarbecoviruses specifically and Betacoronaviruses more generally is needed across a broader global range if we are to avoid future repeats of the COVID-19 pandemic.
Nano-vehicles give new lease of life to existing antimicrobials
Authors: Mela Ioanna , Kaminski Clemens F.
Published: December 2020

Antibiotic resistance has become one of the greatest challenges for modern medicine, and new approaches for the treatment of bacterial infections are urgently needed to avoid widespread vulnerability again to infections that have so far been easily treatable with existing drugs. Among the many approaches investigated to overcome this challenge is the use of engineered nanostructures for the precise and targeted delivery of existing antimicrobial agents in a fashion that will potentiate their effect. This idea leans on lessons learned from pioneering research in cancer, where the targeted delivery of anti-cancer drugs to mammalian cells has been a topic for some time. In particular, new research has demonstrated that nanomaterials can be functionalised with active antimicrobials and, in some cases, with targeting molecules that potentiate the efficiency of the antimicrobials. In this mini-review, we summarise results that demonstrate the potential for nanoparticles, dendrimers and DNA nanostructures for use in antimicrobial delivery. We consider material aspects of the delivery vehicles and ways in which they can be functionalised with antibiotics and antimicrobial peptides, and we review evidence for their efficacy to kill bacteria both in vitro and in vivo. We also discuss the advantages and limitations of these materials and highlight the benefits of DNA nanostructures specifically for their versatile potential in the present context.
Factors influencing the re-emergence of plague in Madagascar
Authors: Alderson Jennifer , Quastel Max , Wilson Emily , Bellamy Duncan
Published: December 2020

Plague is an infectious disease found worldwide and has been responsible for pandemics throughout history. Yersinia pestis, the causative bacterium, survives in rodent hosts with flea vectors that also transmit it to humans. It has been endemic in Madagascar for a century but the 1990s saw major outbreaks and in 2006 the WHO described the plague as re-emerging in Madagascar and the world. This review highlights the variety of factors leading to plague re-emergence in Madagascar, including climate events, insecticide resistance, and host and human behaviour. It also addresses areas of concern for future epidemics and ways to mitigate these. Pinpointing and addressing current and future drivers of plague re-emergence in Madagascar will be essential to controlling future outbreaks both in Madagascar and worldwide.
Tuberculosis diagnostics: overcoming ancient challenges with modern solutions
Authors: MacGregor-Fairlie Michael , Wilkinson Samuel , Besra Gurdyal S. , Goldberg Oppenheimer Pola
Published: December 2020

Rapid, sensitive, accurate and portable diagnostics are a mainstay of modern medicine. Tuberculosis is a disease that has been with us since time immemorial and, despite the fact that it can be treated and cured, it still remains the world's biggest infectious killer, taking the lives of millions annually. There have been important developments in the diagnostic devices for tuberculosis however, these are often prone to error, expensive, lack the necessary sensitivity or accuracy and, crucially, not sufficiently portable and thus not applicable in the remote, rural areas, where they are most needed. Modern solutions have been emerging in the past decade, seeking to overcome many of the inhibiting issues in this field by utilising recent advances in molecular biology, genetics and sequencing or even completely ‘reinventing the wheel’, by developing novel and unprecedented diagnostic techniques. In this mini review, the issues and challenges arising from the historical methods of diagnosing tuberculosis are discussed, followed by outlaying their particular lack of appropriateness for regions of the world where tuberculosis still remains endemic. Subsequently, more recent developments of new methods and technological advancements as ‘modern weapons’ in the battle to defeat this disease and associated challenges are reviewed, and finally an outlook is presented, highlighting the future of the modern solutions under development, which are envisioned to lay the platform for improvements in delivering timely intervention, reduce immense expense and burden on healthcare systems worldwide, while saving millions of lives and eventually, may enable the eradication of this ancient disease.
Grid balancing with a large‐scale electrolyser providing primary reserve
Authors: Samani Arash E. , D'Amicis Anna , De Kooning Jeroen D.M. , Bozalakov Dimitar , Silva Paolo , Vandevelde Lieven
Published: December 2020

As the share of renewable energy sources increases, the grid frequency becomes more unstable. Therefore, grid balancing services will become more important in the future. Dedicated devices can be installed close to the point where off‐shore wind farms are connected to the transmission grid on land. There, they can be used to attenuate power variations, reduce congestion and offer grid balancing. The provision of these ancillary services can create considerable additional economic revenue. In this study, the provision of the primary reserve by means of a large hydrogen electrolyser of 25 MW is investigated for the specific case of the Belgian transmission system. The revenue of the provision of the frequency containment reserve (FCR) is analysed on a techno‐economic model, including capital costs, operational costs, the revenue of the generated hydrogen and oxygen products and the ancillary service income. The revenue depends strongly on the contracted power band. Therefore, it is optimised to yield maximum revenue. The results show that providing FCR creates considerable additional revenue. Therefore, a large electrolyser can be a good candidate to buffer excess renewable energy into green gas while simultaneously providing the grid support.
X-rays observations of a super-Chandrasekhar object reveal an ONe and a CO white dwarf merger product embedded in a putative SN Iax remnant
Authors: Oskinova Lidia M. , Gvaramadze Vasilii V. , Gräfener Götz , Langer Norbert , Todt Helge
Published: December 2020

The merger of two white dwarfs (WDs) is a natural outcome of the evolution of many binary stars. Recently, a WD merger product, IRAS 00500+6713, was identified. IRAS 00500+6713 consists of a central star embedded in a circular nebula. The analysis of the optical spectrum of the central star revealed that it is hot, hydrogen, and helium free, and it drives an extremely fast wind with a record breaking speed. The nebula is visible in infrared and in the [O III] λ5007 Å line images. No nebula spectroscopy was obtained prior to our observations. Here we report the first deep X-ray imaging spectroscopic observations of IRAS 00500+6713. Both the central star and the nebula are detected in X-rays, heralding the WD merger products as a new distinct type of strong X-ray sources. Low-resolution X-ray spectra reveal large neon, magnesium, silicon, and sulfur enrichment of the central star and the nebula. We conclude that IRAS 00500+6713 resulted from a merger of an ONe and a CO WD, which supports earlier suggestion for a super-Chandrasekhar mass of this object. X-ray analysis indicates that the merger was associated with an episode of carbon burning and possibly accompanied by an SN Iax. In X-rays, we observe the point source associated with the merger product while the surrounding diffuse nebula is a supernova remnant. IRAS 00500+6713 will likely terminate its evolution with another peculiar Type I supernova, where the final core collapse to a neutron star might be induced by electron captures.
Comfortable Pedestrian Ways With a Climate Sensitive Urban Design Approach in The Old City Semarang
Authors: Kurniati Rina , Kurniawati Wakhidah , Kusumo Dewi Diah Intan , Sarasadi Annisa , Kartika Syahri Endah
Published: December 2020

The city of Semarang is one of the cities in Indonesia that experiences the phenomenon of heat stroke due to climate change. These conditions cause an increase in the average surface temperature of the city to 22-40 ° C which is included in the category of discomfort for outdoor activities. This is certainly very disturbing for various forms of outdoor activities, such as pedestrian activity. The Old City of Semarang is included in the public area which in the last 5 years seeks to improve the arrangement of the area through the development of pedestrian ways. However, the development that has been carried out is considered not able to create a comfortable climate for pedestrians due to high regional temperatures, especially during the day. For this reason, this study aims to examine how to create a comfortable pedestrian ways to climate change, especially in the Old City Region of Semarang. The method used in the form of analysis of the level of thermal comfort using the ArcGIS application and pedestrian ways analysis using vegetation distribution and building shadow analysis. The result will be found elements of city design that can create pedestrian comfort in the Old City Region of Semarang.
The Effect of CuO/CeO2 Preparation Methods on the HCN Catalytic Removal Efficiency
Authors: Yang Yulin , Yi Zhihao , Sun Jie , Li Jigang , Zhou Tian , Wei Shouping
Published: December 2020

In this paper, the porous CeO2 flowerlike spheres support and a series of CuO/CeO2 prepared by different methods were synthesized. The SEM, XRD, BET, H2-TPR and FT-IR characterization were conducted to probe the physicochemical properties of the samples. To evaluate the HCN catalytic removal efficiency over the prepared samples, the breakthrough time of HCN over different samples were investigated. The results implied the CuO/CeO2 prepared by precipitation method (donated as Ce-5) showed highest catalytic activity, the breakthrough time of which was more than 70 min at 30 °C. It was proved the dispersion of CuO phase on the support, the redox properties and the interaction between CuO and CeO2 support over CuO/CeO2 played an important role in the HCN catalytic removal process. FT-IR analysis demonstrated the CuCN was generated due to the chemisorption of CuO and HCN.
Preparation of nano-TiO2 composite photocatalytic material and its degradation performance on aldehydes
Authors: Lv Yanan , Li Tao , Zhao Honglei , Li Xuepeng , Bu Ying , Xu Yongxia
Published: December 2020

Chitosan-TiO2 photocatalytic composite was prepared using anatase nano-TiO2 and edible chitosan. Fourier Transform Infrared Spectroscopy (FT-IR), ultraviolet visible (UV-vis) and scanning electron microscopy (SEM) was used to characterize the structure of the composites. The photocatalytic degradation performance of the composites was studied by constructing a simulation system. The stability of the combination between chitosan and TiO2 in the composite can be confirmed by the results of FT-IR, UV-vis and SEM. The composite had a good photocatalytic degradation effect. When the addition amount of chitosan-TiO2 was 0.4%, the degradation efficiency of heptanal, octanal, (E)-2-heptenal and (E)-2-octenal reached the highest values of 83.82%, 81.73%, 96.33% and 93.36%, respectively.
The fluid gels: A research review
Authors: Zhang Ke
Published: December 2020

Fluid gels were formed during the sol-gel transition of biological polysaccharide, which were damaged by the shear field and fails to form a static gel network, and the resulting suspension of gel particles were also called shear gel. Modern food design usually requires both deliciousness and health. The special physical properties of fluid gels allow foods with reduced sugar and salt to maintain good texture and physical properties, so they are of great significance in modern product design. This article reviewed the preparation and latest research progress of fluid gels. It demonstrated their unique application prospects for the modern food industry.
First Principle Study on Atomic Scale Structures of Cathode in Aluminium-ion Battery Using Various van der Waals Corrections
Authors: Geng Kaihao , Cao Haining , Lin Meng-Chang
Published: December 2020

There is still controversy on the atomistic configuration of aluminium-ion batteries (AIB) cathode when using first principle calculation based on density functional theory (DFT). We examined the relevant cathodic structures of Al/graphite battery by employing several van der Waals (vdW) corrections. Among them, DFT-TS method was determined to be a better dispersion correction in correctly rendering structural features already found through experiment investigations. The systematic comparison paved the way to the choice of vdW parameters in first principle calculation of graphitic electrode.
Experiment on determination of ethanol chemical shift and concentration of ethanol solution based on nuclear magnetic resonance instrument
Authors: Liang Xinyi
Published: December 2020

In this designing experiment, a nuclear magnetic resonance instrument was used to study the chemical shift properties of ethanol based on the principle of magnetic shielding effect. At the same time, the nuclear magnetic resonance method was used to study the transverse relaxation time and signal strength of ethanol aqueous solution in the range of 5%to 40%. The relationship between different mass fraction of ethanol-aqueous solution and nuclear magnetic resonance signal intensity, relaxation time and solution concentration were analysed. According to the results, due to the limitation of experimental instruments, no regular changes were observed. The results show that the addition of copper sulphate can increase the ethanol content and the effect of the ethanol content on the lateral relaxation time: the ethanol content varies between 5% and 40%, and the lateral relaxation time changes from 8.42ms to 40.35ms.According to the experimental results, the empirical formulas of the concentration and lateral relaxation time of ethanol aqueous solution with fixed amount of copper sulphate were fitted. Using this relationship, the NMR measurement of the concentration of ethanol-water solution can be achieved, which provides a new method for the convenient and accurate measurement of the concentration of ethanol solution.
Prediction of water breakthrough time in horizontal Wells in edge water condensate gas reservoirs
Authors: Huang Quan Hua , Lin Xing Yu
Published: December 2020

Horizontal Wells are often used to develop condensate gas reservoirs. When there is edge water in the gas reservoir, it will have a negative impact on the production of natural gas. Therefore, reasonable prediction of its water breakthrough time is of great significance for the efficient development of condensate gas reservoirs.At present, the prediction model of water breakthrough time in horizontal Wells of condensate gas reservoir is not perfect, and there are mainly problems such as incomplete consideration of retrograde condensate pollution and inaccurate determination of horizontal well seepage model. Based on the ellipsoidal horizontal well seepage model, considering the advance of edge water to the bottom of the well and condensate oil to formation, the advance of edge water is divided into two processes. The time when the first water molecule reaches the bottom of the well when the edge water tongue enters is deduced, that is, the time of edge water breakthrough in condensate gas reservoir.The calculation results show that the relative error of water breakthrough time considering retrograde condensate pollution is less than that without consideration, with a higher accuracy. The example error is less than 2%, which can be effectively applied to the development of edge water gas reservoir.
A Strategy for High-Performance Photodetector based on Graphene-Si heterostructure
Authors: He Tianying , Lan Changyong , Li Chun , Zhou Sihan , Yin Yi
Published: December 2020

Van der Waals heterostructure shows promising applications in next generation optoelectronics. As a kind of van der Waals heterostructure, graphene/silicon (Gr/Si) based heterostructure devices have been demonstrated as high performance photodetectors. Here, we studied the origin of the high performance of Gr/Si photodetectors based on photocurrent mapping technology. According to photocurrent mapping, the photocurrent in the Gr/Si and Gr/SiO2/Si area nearing the Si window edge is higher than that in other positions, which is attributed to the highly effective collection efficiency of photocarriers. A device with size of Gr/Si region (r=7.4 μm) and Gr/SiO2/Si region (L=6.1 μm) shows high sensitivity and a broadband photoresponse in the range from 420 to 1000 nm with the peak sensitivity of 52 A/W at 780 nm, and fast response speed with rise time of 16 μs and decay time of 52 μs. Our study provides a strategy for the design of high photoresponsivity Gr/Si based devices.
Nanoscale mechanical properties and microstructure characterization of ultra-high performance fiber reinforced concrete materials
Authors: Lu Xiaoli , Li Liping , Li Dan
Published: December 2020

The construction of foundation engineering is developing towards high-rise and long-distance direction, and is facing more and more severe environmental threats. Traditional ordinary concrete materials have become increasingly difficult to meet these requirements. Ultra-high performance fiber concrete not only has higher mechanical properties than ordinary concrete, but also has better working performance and durability. Therefore, it can meet the requirements of high-rise, lightweight, intersection and longevity of building structures. The macro properties of materials obtained in different preparation processes are different. The microstructure research of materials links the preparation process with the macro properties from a scientific point of view. Fiber mixing improves the basic mechanical properties and impact fatigue performance of concrete, especially the effect of rigid fiber on improving the mechanical properties of concrete is significant. At the micro level, the fiber can inhibit the formation and development of microcracks. After the microcracks merge into macro cracks, the fibers restrict the crack development and increase the toughness and ductility.
Preparation and physical properties of phthalonitrile composite foam filled with hollow glass microspheres
Authors: Yuan Ping , Qiu Yong , Huang Yuhong , Wu Juying , Fan Jinghui , Zhang Kai , He Ren , Xing Tao
Published: December 2020

In this work, a series of phthalonitrile/hollow glass microsphere (HGM) composite foams for applications in the high temperature and flame retardant fields were prepared and characterized. First, Blends of bisphthalonitrile (CN) and alicyclic imide compounds synthesized from tetrahydrophthalic anhydride (CC) were prepared and sieved (>100 mesh), based on the Thermal Synergistic Polymerization (TSP) effect between phthalonitrile and the alicyclic imide compounds, namely, the -C≡N of the phthalonitrile compound could be completely and rapidly consumed. Then thermogravimetric analysis and rheological behaviors of different molar ratios ofCC/CNblend at different temperatures were investigated. HGM were modified using a silane coupling agent (KH550) to improve the interface interaction between HGM and the resin, thereby improving the properties of composite foam. Finally, a series of composite foams were fabricated and characterized. The performance of the foam prepared by BMC method is much better than that of the foam prepared by “RTM” method. The foam (BMC) shows a density of 0.47 g/cm3with no obvious volume change and little voids, also exhibits good thermal stability up to 400 °C and low thermal conductivity, and provides UL94 V0-rated flame retardancy with total HR of 21.5 KJ/g.
Multi-time scale optimization scheduling of integrated energy system considering demand side response
Authors: Fang Peng , Mao Cui , Chen Yuping , Zhou Shan , You Rui , Xu Danning
Published: December 2020

As the physical carrier of the energy Internet, the integrated energy system has become the focus of current research. Considering the renewable energy and demand side load fluctuations, using the price type and the alternative demand side response characteristics, a day-ahead and intraday optimization scheduling model that takes into account the demand side response is established, in which the intraday, according to the difference of electricity, cold/heat and natural gas scheduling time, a three-layer rolling optimization scheduling model is proposed. The example analysis shows that this model can suppress the fluctuation of renewable energy and load in the day, improve the stability of the system, and further reduce the operating cost of the system.
Analysis of User Energy Consumption Patterns Based on Data Mining
Authors: Liu Weitao , Wang Fuqing , Shi Hang , Zhang Yan , Chen Ruobo
Published: December 2020

The energy use behavior analysis method can dig out the user’s energy use behavior rules from the energy use big data, thereby improving the quality of the grid-side management service in the integrated energy system. Firstly, it summarizes the characteristics of the integrated energy system and constructs the integrated energy system service system; secondly, it summarizes the data-driven electricity consumption behavior analysis research model. Then, it elaborates on the collection and aggregation of electricity consumption information, and refined user classification. Next, the comprehensive application of energy consumption behavior analysis in load forecasting, demand response modeling and other typical scenarios is deeply analyzed. Finally, the challenges that may be encountered in further research are clarified and the follow-up work is prospected.
Research progress of preservative coating of natural polymer materials
Authors: Pan Qingyan , Zhou Chuang , Yang Ziming , He Zuyu , Wang Chao , Gu Hui , Qu Yunhui , Li Puwang
Published: December 2020

The planting area and output of fruits and vegetables in China are the first in the world. However, due to the imperfection of storage and transportation fresh-keeping technology, the annual loss of fruits and vegetables in China is serious. Rational use of fresh-keeping coating is of great significance for improving the shelf life of fruits and vegetables. Natural polymer preservative coating is widely concerned in the field of fruits and vegetables due to its wide sources, degradability, low price and good film-forming ability. In this paper, the types of natural polymer preservative coating were reviewed, and its application in the freshkeeping of fruits and vegetables was summarized and prospected, so as to provide Reference for further research.
Liquid metal based smart fiber sensor for human-computer interaction
Authors: Chen Mingxun
Published: December 2020

Flexible electronic devices based on liquid metal fibers have attracted the attention of many laboratories in the world due to their convenient use and characteristics of being able to be woven into flexible textiles or applied directly on the body surface. In this research, we utilized the liquid metal mixed with copper particles (Cu-EGaIn) as the outer conductive layer of stretchable fiber, developing a highperformance composite conductive fiber based on liquid metal. The composite conductive fiber has three layers: stretchable elastic fiber core; adhesion layer; liquid metal layer. Specifically, the stretchable elastic fiber core provides the high tensile property, the adhesion layer is used to hold the liquid metal on the fiber surface, and the liquid metal layer makes the fiber have a high electrical conductivity. This kind of fiber not only has the characteristic of high electrical conductivity of metal materials, but also can always maintain high electrical conductivity even in large-scale tensile state. Therefore, we developed a tension sensor based on liquid metal intelligent fiber for human-computer interaction.
Building 3D Realistic Modeling Based on Air-ground Multi-source Data Fusion
Authors: Wang Yan , Zhang Tingting , Wang Jingyi
Published: December 2020

Three-dimensional point cloud data is a new form of three-dimensional collection, which not only contains the geometric topology information of the object, but also has high simplicity and flexibility. In this paper, the air-ground multi-source data fusion technology is used to study the fine reconstruction of the 3D scene: based on the 3D laser scanning laser point cloud, the 3D spatial information of the ground visible objects is obtained, and the orthophoto obtained by the drone aerial photography is assisted, Obtain the three-dimensional space information of the top of the ground feature, and the ground three-dimensional laser scanner can quickly obtain the three-dimensional surface information of the building facade, ground, and trees. Due to the complex structure of the building and the occlusion of spatial objects, sub-station scanning is required when acquiring point cloud data. This article uses the Sino-German Energy Conservation Center Building of Shenyang Jianzhu University as the research area, using drone tilt photography technology and ground lidar technology to integrate. During the experiment, the field industry adopted the UAV image acquisition strategy of “automatic shooting of regular routes, supplemented by manual shooting of areas of interest”; in the field industry, the method of “manual coarse registration and ICP algorithm fine registration” The example results show that the ground 3D laser point cloud air-ground image fusion 3D modeling effect proposed in this paper is better and the quality is greatly improved, which makes up for the ground 3D laser scanning. In point cloud modeling, a large number of holes are insufficient due to occlusion and missing top information.
Research and Development of Carbon Dioxide Refrigeration Technology
Authors: Wang Qi , Li Guangpeng
Published: December 2020

With the agreement of the Kigali amendment to the Montreal Protocol, the timetable for the reduction of the mandate and the limitation of 18 controlled substances are being phased in. This has brought great challenges to the transformation, upgrading and sustainable development of China’s refrigeration and air conditioning industry. It has brought great challenges to the transformation, upgrading and sustainable development of China’s refrigeration and air conditioning industry. Carbon dioxide (CO2)is considered to be the most suitable and potential natural working medium due to its excellent environmental properties. This paper introduces the properties of CO2 refrigerant, NH3/CO2 laminated refrigeration system, CO2 secondary refrigerant refrigeration system and CO2 trans-critical refrigeration cycle system, and analyzes three representative processes of CO2 refrigeration system.
Effect of magnetic field on nanofluid free convection in Conical Partially Annular Space
Authors: AISSA Abderrahmane , Amine MEDEBBER Mohamed , Al-Farhany Khaled , SAHNOUN Mohammed , Khaleel Kareem Ali , EL GANAOUI Mohammed
Published: December 2020

Natural convection of a magneto hydrodynamic nanofluid in a porous cavity in the presence of a magnetic field is investigated. The two vertical side walls are held isothermally at temperatures Th and Tc, while the horizontal walls of the outer cone are adiabatic. The governing equations obtained with the Boussinesq approximation are solved using Comsol Multiphysics finite element analysis and simulation software. Impact of Rayleigh number (Ra), Hartmann number (Ha) and nanofluid volume fraction (ϕ) are depicted. Results indicated that temperature gradient increases considerably with enhance of Ra and ϕ but it reduces with increases of Ha.
Asymmetrical Flow Driving in Two-Sided Lid-Driven Square Cavity with Antiparallel Wall Motion
Authors: Azzouz El Amin , Houat Samir
Published: December 2020

The two-dimensional flow in a two-sided lid-driven cavity is often handled numerically for the same imposed wall velocities (symmetrical driving) either for parallel or antiparallel wall motion. However, in this study, we present a finite volume method (FVM) based on the second scheme of accuracy to numerically explore the steady two-dimensional flow in a two-sided lid-driven square cavity for antiparallel wall motion with different imposed wall velocities (asymmetrical driving). The top and the bottom walls of the cavity slide in opposite directions simultaneously at different velocities related to various imposed velocity ratios, λ = -2, -6, and -10, while the two remaining vertical walls are stationary. The results show that varying the velocity ratio and consequently the Reynolds ratios have a significant effect on the flow structures and fluid properties inside the cavity.
Performance Analysis of Different Grid-Connected PV technologies under Fez weather conditions
Authors: Benfares Mourad , Zorkani Izeddine , Seddik Ali Didi , Jorio Anouar , El Ganaoui Mohammed
Published: December 2020

The main objective of this study is to compare the one-year performance of 5.94 KWp grid- connected PV array systems, consisting of three types of mono-Si (2.04KWp), poly-Si (2,04KWp) and a-Si (1,86KWp) photovoltaic solar panels, installed on the roof of the Faculty of Sciences Dhar El Mahraz in Fez. The study is based on data collected in 2017 on energy production. The performance elements evaluated monthly and annually include: energy output, system efficiency, reference yield, final yield, performance ratio, annual capacity factor. The results show that poly-Si technology has the best performance. A comparison between PV Production in different locations in the world and will presented, also we can conclude that Northern Morocco is a good region for PV production.
Biodiesel vs. Diesel Oil in a Marine Engine: A Thermodynamic Study
Authors: Djermouni Mohamed , Ouadha Ahmed
Published: December 2020

The present comparative study deals primarily with the thermodynamic performances of the traditional fuel being used in shipping propulsion, Diesel oil and one of its alternatives, namely, the biodiesel. A thermodynamic model was developed based on the first and second law of thermodynamics. It was found that the engine running on biodiesel registers a slight improvement of its performances compared with the one running on Diesel oil in all the departments considered in this study.
Design of a radiative heat recuperator for steel processes
Authors: Fernandez Arroiabe Peru , Iturralde Iñarga Jon , Gómez de Arteche Botas Mercedes , López Pérez Susana , Ubieta Astigarraga Eduardo , Unamuno Iñigo , Martinez-Agirre Manex , Bou-Ali M.Mounir
Published: December 2020

In recent years, there has been an increasing interest in the recovery of the waste heat of steel and glass processes. This work proposes a numerical study of a waste heat exchanger system for steel production processes. The radiative energy is transferred to a commercial oil, which can be used to produce electricity. The behavior of the recuperator is analysed using a 3D numerical model, considering the constrains of a real production plant. The influence of the radiation properties of the materials on the temperature and heat transfer rate are also examined. The results show that the absorptivity of the tubes influences significantly the absorbed waste heat. Furthermore, heterogeneous mass flow distribution should be applied to optimize the total heat transfer rate.
MRT-LBM simulation of mixed convection in a horizontal channel heated from below by sinusoidal temperature profile
Authors: Sahraoui Nassim Mahfoud , Houat Samir , El Ganaoui Mohamed
Published: December 2020

In this work, a numerical study is carried out to investigate the effect of Rayleigh number on mixed convection in a horizontal channel heated from below by sinusoidal temperature profile and cooled from above. The multiple relaxation time double population thermal lattice Boltzmann method (MRT-TLBM) is used. A validation of our code is done by comparing our results with those found in the literature. Particle oscillation amplitude and temperature profile are plotted for Ra = 5 103, while the Reynolds number, the aspect ratio and Prandtl number are fixed at Re = 10, B=10, Pr = 0.667 respectively. The effect of Rayleigh number on the heat transfer is also discussed.
Study of Air Movement and Temperature Distribution in a Greenhouse Used as a Dryer
Authors: TIGAMPO Soumaïla , SAMBOU Vincent , DIEYE Younouss , TOURE Pape Moussa , BODIAN Séckou
Published: December 2020

Sun-drying is the oldest way to preserve, store and also to enhance the value of our agricultural production. Nowadays, several types of dryers have been developed but the greenhouse is an ideal solution for drying in our tropical countries because the sun is abundant. But the control of the greenhouse climate depends on several factors, namely the external climatic conditions but also the type of materials used in the greenhouse. The study was carried out in a greenhouse, tested under the climatic conditions of Dakar. It is in this context of sustainable development that this work, whose objective is to contribute to the improvement of drying conditions for agricultural products, is carried out and to achieve this, the distribution of temperatures and speeds in the greenhouse must be determined. For the three-dimensional CFD simulation, we added a discrete radiation model to solve the radiation transfer equation and the Solar Load Model which gives the position of the sun and its radiation. The simulated air temperatures give an average of 52.8°C with average air velocities that are around 0.114 m/s in the closed greenhouse and the results found can be used to improve the design and control of the greenhouse climate.
Beneficial Effect of Incorporation of Slag on the Hydration Heat, Mechanical Properties and Durability of Cement Containing Limestone Powder
Authors: Boubekeur Toufik , Boulekbache Bensaid , Salhi Mohamed , Ezziane Karim , Kadri EL.Hadj
Published: December 2020

This paper presents the experimental results of a wide research program, tending to determine the hydration mechanism, mechanical properties and the durability performance of ternary cement containing limestone powder and slag. The limestone powder increase the hydration at early ages inducing a high strength at, but it can reduce the later strength due to the dilution effect. On the other hands, Slag (S) contributes to increase the compressive strength at later ages. Hence, at medium blended cement (OPC-LP-S) with better performance could be produced. Results show at later age the Slag is very effective in producing ternary blended cements with similar on higher compressive strength than the ordinary Portland cement at 28 and 90 days. For durability, the incorporation of the slag into the cement containing limestone powder improves remarkably resistance to attack by acids and sulfates and it has been found that the durability of the cements never depends on the mechanical strength.
Celebration of the centenary of a major scientific milestone thanks to Heinrich Barkhausen
Authors: Salzenstein Patrice , Pavlyuchenko Ekaterina
Published: December 2020

Brief history of a perfect optimization with the oscillation condition and microwave tube as well as contributions to oscillators at the occasion of the centenary of a great step forward thanks to genius Heinrich Barkhausen with his pages of glory in the years 1919–1920.
Analysis of Surgical Recurrence after Larynx Microsurgery for Benign Lesions
Authors: Patrial Maria Theresa Costa Ramos de Oliveira , Hamerschmidt Rogério , Matias Jorge Eduardo Fouto , Filho Evaldo Dacheux de Macedo , Carvalho Bettina
Published: December 2020

Introduction The study of larynx lesions is of great importance. More than 50% of people with vocal complaints have benign vocal fold alterations and some require surgery.

Objective To determine which factors are related to surgical recurrence of benign laryngeal lesions and to determine which videolaryngoscopic diagnoses are related to the risk or protection of surgical relapses over time.

Methods Observational, analytical, cross-sectional study with retrospective data collection of 1,383 surgeries in 1,301 patients.

Results The mean age at the first surgery was 39.2 years old. The predominant gender was female (65.6%).

There were 396 cases of polyps (25.34%), 349 cases of cysts (22.33%), 261 cases of Reinke edema (16.7%), 175 cases of nodules (11.2%), 153 cases of minor structural alterations (MSAs) (9.79%), 94 cases of leukoplakia (6.01%), 77 cases of granulomas (4.93%) and 58 cases of pseudocysts (3.71%). The age presented statistical significance with the risk of surgical relapses (p = 0.016). Male gender was associated with the greatest chance of relapse.

Diagnosis of granuloma (p < 0.001) and of leukoplakia (p < 0.001) were associated with a higher risk of surgical recurrence. Cyst diagnosis was associated with protection (p = 0.015) in relation to the chance of further surgeries. Patients with associated lesions, bilaterals or voice professionals did not present a statistically significant association with surgical recurrence.

Conclusion Age and gender are statistically related to the increase of surgical relapses. Leukoplakia and granuloma are associated with increased surgical relapses. Patients submitted to cyst microsurgery appear to be protected against surgical recurrence.
Micro/nanofiber-based noninvasive devices for health monitoring diagnosis and rehabilitation
Authors: Ghosh Rituparna , Pin Koh Yi , Reddy Vundrala Sumedha , Jayathilaka W. A. D. M. , Ji Dongxiao , Serrano-García William , Bhargava Suresh K. , Ramakrishna Seeram , Chinnappan Amutha
Published: December 2020

Recently, in healthcare sectors, specifically for personalized health monitoring, motion sensing, and human–machine interactions, the rising demand for stretchable and soft electronic devices is significant. In particular, stretchable, skin mountable, breathable, wearable, light weight, and highly sensitive sensors are needed for detecting subtle deformation arising from human physiological signals and have potential applications in health diagnosis. In this review, we discuss flexible, noninvasive, and wearable sensors based on micro/nanofibers with unique sensing capabilities for detecting human vital signs such as body motion, temperature, heartbeat, respiration rate, and blood glucose level, which have applications in both fitness-monitoring and medical diagnosis. Here, the latest successful examples of micro/nanofiber based flexible and wearable human vital signs monitoring sensors in the form of film, mat, yarn, fabric, textiles, etc., are outlined and discussed in detail. Discussion includes the fiber fabrication technique, sensing mechanism, device structure, sensor performance, and data processing. Some of the latest fabricated self-powered devices with integrated sensing platforms are also reviewed. Finally, this article reveals the existing challenges that are still to be overcome associated with wearable technologies for applications in health monitoring, diagnosis, and rehabilitation.
Water-soluble energy harvester as a promising power solution for temporary electronic implants
Authors: Zhang Qian , Liang Qijie , Rogers John A.
Published: December 2020

Implantable biomedical devices are rapidly advancing for applications in in vivo monitoring and intervention for human health. A frontier for this area is in electronic implants that function in the body for some period of time matched to an intrinsic body process and then disappear naturally, thereby avoiding the need for surgical extraction. Continuous and stable power supply to these systems is of utmost importance for their practical implementation and function. Energy harvesters that are water soluble to biocompatible end products have great potential in this context. This article presents a comprehensive review of recent progress with a focus on materials selection, device integration, and function extension. We also discuss the challenges and possible future research opportunities associated with these technologies, with a focus on implantable biomedical devices.
Ultrasound in air
Authors: Leighton Timothy G.
Published: December 2020

Experimental studies of the underlying physics are difficult when the only sensors reporting contemporaneous data are human beings.