bluuebunny/crossref_metadata_2025 huggingface dataset:
Complementary diagnostics of high-intensity femtosecond laser pulses via vacuum acceleration of protons and electrons
Authors: Vais O E , Bychenkov V Yu
Published: November 2020

Taking advantage of complementary measurements of the characteristics of both protons and electrons accelerated by a laser in a vacuum, we propose an advanced diagnostics of the parameters of the tightly focused high-intensity femtosecond laser pulse. The laser field description is based on Stratton–Chu integrals, which allow simulating laser pulses with different spatial–temporal profiles focused by an off-axis parabolic mirror down to the diffraction limit. The free particles, whose dynamics are calculated by the test particle method, are accelerated from a rarefied gas (almost a vacuum). We analyze the dependence of the particle spectra on the laser parameters: the laser peak intensity, focal spot size, and pulse duration. The results show that diagnostics obtained by simultaneously using protons and electrons allow increasing the estimation accuracy of measuring the focal spot size and the peak intensity and thus allow evaluating the laser pulse duration in the femtosecond range. Our proposal is a response to the urgent need to measure pulse durations in the focal spot for new PW-level class lasers of super-short duration up to ∼10 to 20 fs, which clearly demonstrate a current trend in laser technology.
Optical design and tolerance of a high efficiency laser polarization grating-polarization conversion system based and diffraction limited heads up display projector
Authors: Mousavi Fard Sayed Sajjad , Farhadian Amir Hossein , Abbasabadi Majid
Published: November 2020

In this paper, a compact and diffraction limited heads up display (HUD) image source is presented. The great benefit of this design is its diffraction limited optic, compacted structure, economic considerations, simplicity in manufacturing and high efficiency image quality. The innovation of this design is the use of a polarization grating-polarization conversion system (PG-PCS). This module transforms the unpolarized Gaussian beam to a linearly polarized beam and it simultaneously homogenizes the spatial intensity profile. With this module, it is possible to increase the efficiency of illumination and to utilize the ordinary micro LCD instead of using a digital micro mirror device (DMD) and liquid crystal on silicon (LCOS) micro displays. The diameter of the image plane is 76.2 mm (in accordance with conventional types). Our design yielded uniform illuminated image and its high efficiency facilitates display readability in see-through HUDs operating in high ambient light as well as low ambient light.
A high-sensitive methane measuring telemetry system based on a direct optical absorption technique
Authors: Dong Lulu , Yao Yongping , Zhao Yuqing , Cui Na , Liu Shande , Zhang Huiyun , Zhang Yuping , Xu Yan
Published: November 2020

In this paper, a reflective methane (CH4) gas telemetry system has been developed based on the direct optical absorption spectroscopy technique for an open light path. It can realize the real-time in-situ monitoring of CH4 gas within a range of 150 m. Considering the potential cross-interference effects of hydrocarbon gases in ambient air, a diode laser operating at a specific wavelength of 1653.7 nm is employed to target the strong CH4 absorption line in near-infrared region and therefore avoid the interference of water vapor absorption simultaneously. A measurement precision of 0.02 ppm within 40 m open optical path has been achieved over 30 h of continuous monitoring, indicating the excellent measuring sensitivity and stability of our telemetry system. Through the field test of leaked CH4 gas with a 150 m one-way open optical path, the developed CH4 telemetry system has proved to have great potential and reliability for environmental monitoring and remote gas detection in various industries.
1.3 μm passively Q-switched mode-locked laser with Fe3O4 nanoparticle saturable absorber
Authors: Zhang Huaiwei , Peng Jiying , Yao Jianquan , Yang Xiangpeng , Li Decai , Zheng Yi
Published: November 2020

Fe3O4 nanoparticles (FONP) are made into saturable absorbers and assembled into the resonant cavity, for the first time, and passively Q-switched mode-locked (QML) pulse output is realized in a 1.3 μm all-solid-state laser. When the pump power increases to 8 W, the repetition frequency of the Q-switched pulse increases from 47 kHz to 116 kHz, the pulse width changes from 1.137 μs to 767 ns, and the corresponding single pulse energy is 1.2 μJ. At the same time, the passively QML operation was observed on the oscilloscope, with a pulse repetition frequency of 154.5 MHz and a pulse width of 660 ps. Our experiments demonstrate that FONP exhibits good nonlinear optical characteristics in the 1.3 μm waveband, and has the potential to realize giant ultrashort and multiwavelength tunable pulse output in all-solid-state pulsed lasers.
Highly-precision sizing a single metal nanoparticle using a microcavity
Authors: Li Ling , Yang Wen-Xing , Shui Tao , Wang Xin , Li Xi-Yun , Wu Zhen
Published: November 2020

Precision measurement plays a very important role in many field including optics, astronomy, biochemistry, atmospheric science, environmental engineering, dusty plasma, etc. Here, we propose an efficient scheme to investigate the relationship between linewidth and radius of the metal nanoparticle (MNP) in a hybrid optical microcavity system that included a quantum emitters interacting with a MNP. By using detailed numerical simulations and analytical modeling, we find that the linewidth of the amplification window is sensitive to the radius of MNP. Subsequently, we discuss the application of such a hybrid optical microcavity system as a family of high-sensitivity sensor for measuring the tiny radius of the MNP. Using experimentally achievable parameters, we identify the detection sensitivity of the sensor can arrive at approximately 2.6 GHz nm−1. The present investigation provides a route toward guiding the design of sensitive devices.
Dual stream neural networks for brain signal classification
Authors: Kuang Dongyang , Michoski Craig
Published: November 2020

Objective. The primary objective of this work is to develop a neural nework classifier for arbitrary collections of functional neuroimaging signals to be used in brain–computer interfaces (BCIs).Approach. We propose a dual stream neural network (DSNN) for the classification problem. The first stream is an end-to-end classifier taking raw time-dependent signals as input and generating feature identification signatures from them. The second stream enhances the identified features from the first stream by adjoining a dynamic functional connectivity matrix aimed at incorporating nuanced multi-channel information during specified BCI tasks.Main results. The proposed DSNN classifier is benchmarked against three publicly available datasets, where the classifier demonstrates performance comparable to, or better than the state-of-art in each instance. An information theoretic examination of the trained network is also performed, utilizing various tools, to demonstrate how to glean interpretive insight into how the hidden layers of the network parse the underlying biological signals.Significance.The resulting DSNN is a subject-independent classifier that works for any collection of 1D functional neuroimaging signals, with the option of integrating domain specific information in the design.
Research on Path Calculation and Simulation System of Variable Parameter Manipulator
Authors: Li Jiacheng , Yang Xiaoli , Wu Xian , Zhong Liangwei
Published: November 2020

The simulation software of manipulator is generally developed by manufacturers, and the products are only suitable for the specific company, but cannot be used in universal. Aiming at this problem, this paper establishes a mathematical model with attributes through parametric design. The standard D-H parameter method is used to model the kinematics of the manipulator. Based on the expert system, the intelligent path planning of the manipulator is carried out, and the trajectory control instructions of the manipulator are generated. According to the Monte Carlo method of point cloud, the workspace of manipulator is obtained, and the bounding box technology is used for real-time collision detection. Taking the welding work as an example, the parametric modelling and trajectory planning simulation of the manipulator are realized, and a general off-line programming platform is established.
Influences Analysis of Dynamic Response for Slope Supported by Frame with Anchors under Different Anchor Intervals
Authors: Feng Xiaojun , Ye Shuaihua
Published: November 2020

This article based on the practical engineering in the northwest loess area in China, considered the interaction and collaborative work of frame-anchor-soil, with the help of the finite element software ADINA, established a 3D finite element model of the frame prestressed anchor supporting slope system under earthquake action. In the model, the soil was simulated by elastic-plastic model, and a bilinear elastic model was used to simulate the anchor, friction-element was used to describe the interaction between soil and frame (beams, columns and retaining plate), the frame is simulated by a bilinear elastic-plastic model. By inputting bidirectional seismic waves, the dynamic response of the supporting system under different horizontal and vertical spacing of anchors was compared and analyzed. Finally, obtained the influence law of different anchor spacing on the slope seismic response.
Customer Classification Method of Logistics Enterprises Based on BP-AdaBoost
Authors: Shi Xianming , Li Guangning , Li Kang , Liu Junyan , Wang Rongcai
Published: November 2020

Effective customer classification is a key issue for logistics enterprises to carry out customer relationship management, which has been concerned and studied by relevant institutions. Based on BP and AdaBoost algorithm, a new customer classification method for logistics enterprises is proposed. First of all, the logistics customer value evaluation index system is designed, and the different customer characteristics are analysed. Secondly, in order to solve the problem of low accuracy of the traditional BP network, the AdaBoost algorithm is used to linearly combine the traditional BP network to produce a strong classifier. The simulation results show that the application of the new customer value classification method based on BP-AdaBoost in customer classification improves the classification accuracy.
Research on Class Combination Algorithm Based on Genetic Algorithm
Authors: Yan Linjing , Kong Xiangming
Published: November 2020

The scheduling problem is a typical multi-objective optimization problem, and the core problem involved is the problem of combining classes. On the basis of a comprehensive analysis of the problem of class combination, this paper establishes a mathematical model of the three-dimensional class combination problem according to the needs, and constructs the chromosome expression in the genetic algorithm, and obtains the optimal solution of the problem. Experiments show that this algorithm can effectively obtain the optimal three-dimensional class combination program, and has strong practicability.
Rule-based Data Quality Intelligent Monitoring System
Authors: Zhang Huayun , Wang Shaolei , Wang Xiang
Published: November 2020

The rapid development of Internet information technology brought great convenience to people’s lives and work, but it also brought the problem of information overload[l]. The data center is the middle layer that mediates the contradiction between the foreground and the background[2]. It provides a reusable, standardized, and agile multifunctional platform through the modeling of background data and the aggregation of data services to support the foreground for the demand[3] of quickly change according to market changes. Through the data center, we have opened up the data islands of each business system. However, when each business system uses data, it found that the data quality is poor, unstable, not timely, and inconsistent. Traditional cluster data quality monitoring has the characteristics of inconsistent data quality requirements for various services, difficult development, low processing efficiency, difficult maintenance, and insufficient intelligence.

Based on this situation, we design a data quality monitoring system based on rules and artificial intelligence. General users perform simple configuration on the interface to complete real-time online monitoring of data, and real-time statistics on the number of data quality problems and a detailed list for users to trace the cause of the problem and identify abnormal scenarios in advance. The comparison between experiments and mainstream products proves that the system has greatly improved in terms of user use and flexibility.
Pricing Research on Cloud Manufacturing Service Based on Game Theory
Authors: Han Tiaojuan , Lu Jianfeng , Qian Lin , Tao Li
Published: November 2020

The pricing of the cloud manufacturing service was critical for the success of service transaction. Firstly, based on the hotelling model, this paper discussed the pricing and revenue of providers on the cloud platform for service trading. In the cloud service transaction, the cloud platform is generally the leader of service providers. Therefore, we further proposed the stackelberg game model, in which the pricing of the manufacturing service was determined by the profit ratio of the cloud platform. Thirdly, basing on the utilization rate of the manufacturing service, we adjusted the determined pricing of manufacturing service dynamically to cope with unpredictable service demand. Finally, we compared the price and benefit between the proposed model and the traditional hotelling model. The result shows that the price and revenue of the manufacturing service are improved by introducing cloud platform. In the future, we should consider demanders’ revenue and other factors on the price.
Stiffness Identification Method of Simply Elastic Supported Beam based on First-order Modal Rayleigh Solution
Authors: Wang Shujuan , Qin Xuxi , Yu Limei , Tian Bing
Published: November 2020

In order to evaluate the support state of bridges with elastic supports, based on first-order mode Rayleigh solution, a stiffness identification method of elastic supports beam is proposed. The superposition displacement of static displacement and rigid body displacement under sinusoidal load is used as the vibration mode function. Based on the mode function, the calculation formula of the fundamental frequency for the simply supported elastic support beam is derived according to the Rayleigh method. The identification method of the support stiffness and beam stiffness of the elastic support beam is derived by using the measured frequency and the mode value. A precast box girder is analyzed by an example. According to the measured results and finite element results, the stiffness of the precast box girder and the stiffness of the laminated rubber bearing are identified by the stiffness identification method established.
Game Analysis on Managerial Entrenchment and Enterprise Investment Myopia
Authors: Li Meng , Li Bingxiang , Zhang Dan
Published: November 2020

We analyse the effect of managerial entrenchment on myopic investment behaviour and the corresponding response of shareholders using a two-stage signaling game model. From the dimensions of capability and job-switching costs, we categorize managers into three types: talented managers with high job-switching costs (M
TH), talented managers with low job-switching costs (MTL) and untalented managers (M
u). We determine a pooling equilibrium in which all types of managers prefer to select short-run projects under managerial entrenchment motivation. The results reveal that managerial entrenchment motivation and action will contribute to investment myopia. Furthermore, a partially separating equilibrium in which M
TL select short-run projects but M
TH and M
u select short-run projects emerges if the optimal subsidy is given to managers. Meanwhile, shareholders decide whether or not to retain incumbent managers according to the project yield
Lighting Design and Statistical Analysis on Sunshine Underground garage
Authors: Qu Wanying , Cheng Wei , Liu Congru
Published: November 2020

In view of the current status of underground garages, the underground sunshine garages are used in the architectural design. After the completion of Tongcheng Yuli community, the questionnaire survey and field measurement were conducted simultaneously. The statistical method was used to analyze the data and the conclusions are as follows: the illumination under skylight is higher. As the distance from the skylight is further away, the speed of illumination decline is first fast and then slow. An exponential distribution occurs. Lane illumination and distance is also exponentially. In the case of unilateral day lighting, the minimum illumination requirement is 301x, the distance limit is 14.5 meters and there are basically 2 columns. On both sides, the distance of the daylighting port is 30 meters, and there are basically four columns around. The comfortable condition are analyzed in the underground garage. This paper will provide reference for the design in the underground sunlight garage.
An Airport Gate Assignment Model by Considering Multiple Constraints Deriving from Business Rules
Authors: Zhang Jun , Yi Bin , Yu Baohui
Published: November 2020

Airport gate is the core resource for airport operation and organization, and thus an optimal airport gate assignment (AGA) schedule plays a critical role to ensure the high-efficiency airport operation. In this paper, considering the actual business rules of airport, the AGA problem is explored and a model based on the actual business rules of airport is established. The model aims to maximize the passenger docking rate and comprehensively considers several constraints deriving from business rules, such as the limitation of adjacent aircraft models, conflict of slide in and out and gate conflict restrictions. The actual business rules of airport are abstracted into the objective functions and constraints of the model. In view of the large-scale complicated combinational optimization problem deriving from the model, an improved immune genetic algorithm is designed to solve the model. Based on the traditional immune genetic algorithm, the proposed algorithm further integrates the variety of population, adaptive crossover probability and memory library to improve the solving efficiency. Moreover, a numerical experiment is designed by using the real-world data from Kunming Changshui International Airport. The experimental results indicate that the proposed model and algorithm have feasibility and effectiveness. The optimal assignment schedule has ability to increase the berth utilization ratio for both passengers and flights.
Regional Distribution of Tropical Agricultural Industry at Home and Abroad and Enlightenment to Hainan Agriculture
Authors: Zhang H. J. , Jiang J. , Wang C. L. , Sun H. Y. , Zhao J. M. , Huang H. L.
Published: November 2020

The layout and development of tropical agriculture is very important to the construction of Hainan Free Trade Port (HNFTP). Only by reasonably planning to the agricultural layout, the agricultural development could be promoted and met the needs of developing Hainan Free Trade Port (HNFTP). To scientifically and effectively plan Hainan’s agricultural spatial layout, this research thinks about the agricultural spatial layout of developed areas as a reference could be taken into consideration, and combine with the local characteristics, formulate guidelines, overall planning, and specific implementation.
The Model of How Languages will Develop
Authors: Sun W. , Wang J. , Zhang H. , Hou X.
Published: November 2020

The total number of speakers of a language may increase or decrease over time because of various and complicated influences. In this paper, we build the quantitative prediction model based on gray estimation, FCM model and geographical distribution prediction model to predict the distribution of language users. In addition, we conducted a sensitivity analysis of the model to facilitate future research.
Meteorological conditions contributed to changes in dominant patterns of summer ozone pollution in Eastern China
Authors: Yin Zhicong , Ma Xiaoqing
Published: November 2020

Ground-level O3 pollution has become one of the most consequential air quality problems in China. Many previous studies have addressed the increasing trend of surface O3 concentrations in Eastern China. In this study, a new feature, i.e. the change in the dominant patterns of surface O3, was revealed, and the associated physical mechanisms were analyzed. The impacts of meteorological conditions and anthropogenic emissions were separated, and the change in the O3 dominant pattern was found to be mainly due to the variability in the meteorological conditions. From 2017 to 2019, the stable confrontation of the western Pacific subtropical high (WPSH) and East Asian deep trough (EADT) was closely related to the south-north covariant pattern of O3, because the variability in the meteorological conditions centered on the North China and Huanghuai regions. In the period of 2015–2016, the joint movements of the WPSH and EADT modulated the meteorological anomalies, creating a dipole mode in Eastern China that contributed to out-of-phase variations in O3 in North China and the Yangtze River Delta.
Polynomial algebras from su(3) and a quadratically superintegrable model on the two sphere
Authors: Correa F , del Olmo M A , Marquette I , Negro J
Published: November 2020

Construction of superintegrable systems based on Lie algebras have been introduced over the years. However, these approaches depend on explicit realisations, for instance as a differential operators, of the underlying Lie algebra. This is also the case for the construction of their related symmetry algebra which take usually the form of a finitely generated quadratic algebra. These algebras often display structure constants which depend on the central elements and in particular on the Hamiltonian. In this paper, we develop a new approach reexamining the quadratically superintegrable system on the two-sphere for which a symmetry algebra is known to be the Racah algebra R(3). Such a model is related to the 59 two dimensional quadratically superintegrable systems on conformally flat spaces via contractions and limits. We demonstrate that using further polynomials of degree 2, 3 and 4 in the enveloping algebra of su(3) one can generate an algebra based only on abstract commutation relations of su(3) Lie algebra without explicit constraints on the representations or realisations. This construction relies on the maximal Abelian subalgebra, also called MASA, which are the Cartan generators and their commutant. We obtain a new six-dimensional cubic algebra where the structure constant are integer numbers which reduce from a quartic algebra for which the structure constant depend on the Cartan generator and the Casimir invariant. We also present other form of the symmetry algebra using the quadratic and cubic Casimir invariants of su(3). It reduces as the known quadratic Racah algebra R(3) only when using an explicit realization. This algebraic structure describes the symmetry of the quadratically superintegrable systems on the 2 sphere. We also present a contraction to another six-dimensional cubic algebra which would corresponding to the symmetry algebra of a Smorodinsky–Winternitz model.
Mechanical Properties of Hybrid Polymers for Break pad Applications.
Authors: Ravi Raj V , Vijaya Ramnath B , Srinivsan R , Sethuvelappan P , Ramanan
Published: November 2020

Non wear out brake emission is one of the significant issue concerns with health and the environment. In brakes performance, wear debris is released in the atmosphere and pollute the environment. The brake pad is classified into two categories mainly asbestos and non-asbestos. As per the report of WHO and Environment Protection Agencies, some of the metals oxidized and produces toxic gaseous. Toxicity leads and creates a bad effect on human health. This work focuses on remedies over environmental and health issues because of brake pad emission. It is important to reduce the percentage of toxic elements at source and develop novel material compositions that are less dangerous to the environment and human health. Also, it satisfies all requirements of a brake pad material as per international standards. From this investigation, we found an alternate material for brake bad applications. The natural fibers reinforcement material is zero toxic. So, the materials will not create any environmental and human health issues.
Investigation on Mechanical Strength of Cellular Concrete in Presence of Silica Fume
Authors: Fani G M , Singla S , Garg R , Garg R
Published: November 2020

Over the past decade, Cellular Lightweight concrete has gained popularity in the construction industry. Despite its advantageous low weight, thermal insulating, and fire-resistant nature, its comparatively low strength is a matter of concern. To develop the strength of this type of concrete, a thorough characterization of its main characteristics must be studied thereafter in addition to supportive cementitious materials. The effect of polyurethane on density and strength of cellular concrete subjected to varying curing conditions have been investigated in this report. Besides, Silica Fume has been used as a partial substituent of cement and as supportive cementitious material. The cellular concrete has been obtained by varying silica fume (0-20% by weight of cement) and polyurethane (0-20% by volume) at 7, 28, 56, and 90 days of curing. Density, compressive strength, split tensile strength and flexural strength have been investigated for all the specimens. The findings revealed a decrease in density and strength of cellular concrete in the absence of SF and the presence of polyurethane. The introduction of silica fume resulted in higher density and strength revealing the beneficial use of this pozzolanic material.
Mechanical Properties and Durability Study of Jute Fiber Reinforced Concrete
Authors: Tiwari S , Sahu A K , Pathak R P
Published: November 2020

Natural material/fiber should be used in the construction industry as it finds low cost and improve the properties of the material. Jute fiber is used in research study and carried out an experimental investigation on the mechanical properties of the jute fiber reinforced concrete (JFRC). Natural available jute fiber was chopped to the desired length and it was mixed in concrete to produce JFRC. The chopped jute fiber added in three different percentages i.e. 0.5%, 1.0%, & 1.5% in three various concrete mixes (M25, M30 and M40). Additionally, JFRC concrete specimens cured in the acid medium and examine the compression strength, split tensile strength, and strength reduced under acid curing. Workability results indicated that the slump value (workability) reduced as an increased amount of jute fiber in the concrete specimens. Also, the compressive strength reduced in the acid curing as compared to normal curing. Additionally, Jute fiber increased the compressive and tensile strength of every concrete mix. This research study revealed that natural fiber (jute fiber) can be used as additives to enhance the durability and strength of concrete.
Performance analysis of Papercrete in presence of Rice husk ash and Fly ash
Authors: Singh A , Singla S , Garg R , Garg R
Published: November 2020

Papercrete is a modern composite material, that uses waste paper as a partial replacement to Portland cement, and is a renewable medium to construction owing to the reduction of the volume of waste paper as well as cement. Papercrete has strong sound absorption, thermal insulation and a low-cost alternative; light weight and fire-resistant building material. However, its low mechanical strength needs to be compensated by incorporation of supplementary cementitious materials. The work discusses the potential for the partial replacement of cement (by weight) with waste paper pulp in presence of Rice husk ash (RHA) and fly ash (FA) in ternary blends. For tests, the levels of replacement for RHA and FA were 10%, 15%, 20% and 25% and for waste paper, the rates of replacement were maintained at 10%. A reference mix was also prepared for the comparative purposes without substitution by RHA, FA and paper pulp. The flow, compressive strength, split tensile strength, water absorption and dry density studies were performed for all the specimens. The findings revealed decreased the flow of specimens compared with the reference mix along with reduction in strength that was well compensated by RHA and FA particles. The optimal content for RHA blends was 20% and that of FA was 15% with maximum strength among the mixes. The study signifies that the waste paper can be used to prepare papercrete in presence of optimal content of supplementary cementitious materials to have desired mechanical properties.
Green Synthesis and Characterization of Copper Oxide Nanoparticles Using Psidium guajava Leaf Extract
Authors: Varughese Ammu , Kaur Raminder , Singh Poonam
Published: November 2020

Green synthesis of nanoparticles has gained enormous attention in today’s world due to ongoing demand to develop safe, sustainable, cost-effective and environmentally friendly process for synthesizing a wide variety of materials including metal/metal oxides nanoparticles, hybrid and bioinspired materials. In the current study, we have carried out green synthesis of copper oxide (CuO) nanoparticles (NPs) using psidium guajava leaf extract as capping agent and copper acetate as metal precursor. The biosynthesized nanoparticles were characterized using wide variety of techniques i.e. powder X-ray diffraction (PXRD), FTIR, TGA and HRTEM. The PXRD result confirms the synthesis of copper oxide nanoparticles in pure phase having monoclinic symmetry. The average particle size using PXRD was found out to be ∼33 nm.
Effect of Silica Fume & Steel Slag on Nano-silica based High-Performance Concrete
Authors: Kansal C M , Singla S , Garg R
Published: November 2020

This study presents strength behaviour of concrete based composites including three different ternary binders namely Nano-Silica (NS), Silica Fume (SF) & Steel Slag (SS). NS as fragmental substitution of cement, SF as the fragmental substitution for the fine aggregates and SS as fragmental substitution of coarse aggregates has been used. The study has been conducted at an optimized content of NS (2%) and by varying the content of SF (10-15%) and SS (10-30%). Cement concrete having M60 grade strength at fixed W/C (0.35) has been explored for the strength behaviour. The studies have revealed that the optimized content of NS, SF and SS can be used as a partial substitute of cement, fine aggregates and coarse aggregates respectively to obtain increased strength. Thus, NS, SF and SS can be used to obtain high performance and eco-friendly concrete structures.
Mechanical Properties of Chemically Treated Banana and Ramie Fibre Reinforced Polypropylene Composites
Authors: Sai Krishnan G. , Shanmugasundar G. , Vanitha M. , Sivashanmugam N.
Published: November 2020

Present research focuses on finding better fibre reinforcement cheap and eco-friendly polypropylene composite Mechanical Properties increased with increase in fibre loading and sodium carbonate Treatment. Banana and Ramie Fibres were chosen as reinforcement. The compression moulding technique was used to prepare the composite material. Fibre loading was varied at 0, 5 and 10% volume. Both raw Banana and Ramie Fibre was chemically treated with 5 wt% sodium carbonate and composites were also prepared with 0, 5 and 10% volume treated ramie and banana fibre. Analysis of prepared composites was subsequently conducted using Mechanical Tensile, flexural, hardness tests and. 10% fibre reinforced composite provided the best set of mechanical properties. It can be concluded after chemical treatment the mechanical treatment got enhanced.
Investigation on the Mechanical and Morphological Properties of Red banana/Ramie Fiber vinyl ester composites
Authors: Sai Krishnan G. , Shanmugasundar G. , Vanitha M. , Srinivasan S. , Suresh G.
Published: November 2020

The need of green materials for various applications is in high demand. The bio fibers play a very important position to achieve eco friendliness and cost effectiveness. The aim is to analyse the effect of hybrid mat performance. In this work banana and ramie fibers were taken into consideration, With vinyl ester composites. Three different combinations have been developed in laminating the composites at 90 degree orientation. ASTM standards were used to examine the mechanical performances of the composites. The worn out analysis have been carried out by using scanning electronic microscopy. In this work two single layer fibers of ramie and banana have been taken into account and the third composite is developed with hybridisation of red banana and ramie fibers. On comparing all the results obtained the hybrid double layer of red banana and ramie fibers possessed good results in tensile/flexural property. The impact properties of ramie fiber were marginally higher than red banana fibers.
Study on the ball milling modification of attapulgite
Authors: Xu Jianlin , Ren Shibo , Kang Chenghu , Cui Fandong , Li Chengsi , Fan Jiliang
Published: November 2020

In order to improve the dispersion of attapulgite (ATP), the surface of ATP was modified by conventional ball milling, chemical modification and ball milling modification methods. The ATP samples were studied by XRD, FTIR, TG, TEM, etc. The research results show that the resulting ATP modified by conventional ball milling still has the secondary agglomeration phenomenon and partial damage phenomenon of its rod-like crystal. The surface of ATP can be effectively modified by silane coupling agent KH-550 using chemical modification and ball milling modification methods and their rod-like crystal cannot be damaged. The ball milling modification and dispersion effects for ATP was the best. The contact angle of the resulting ATP was increased by 189% , its specific surface area was increased by 218% , and the volume of the bundles and the sedimentation rate were decreased.
Methods for measuring the electron’s electric dipole moment using ultracold YbF molecules
Authors: Fitch N J , Lim J , Hinds E A , Sauer B E , Tarbutt M R
Published: November 2020

Measurements of the electron’s electric dipole moment (eEDM) are demanding tests of physics beyond the standard model. We describe how ultracold YbF molecules could be used to improve the precision of eEDM measurements by two to three orders of magnitude. Using numerical simulations, we show how the combination of magnetic focussing, two-dimensional transverse laser cooling, and frequency-chirped laser slowing, can produce an intense, slow, highly-collimated molecular beam. We show how to make a magneto-optical trap of YbF molecules and how the molecules could be loaded into an optical lattice. eEDM measurements could be made using the slow molecular beam or using molecules trapped in the lattice. We estimate the statistical sensitivity that could be reached in each case and consider how sources of noise can be reduced so that the shot-noise limit of sensitivity can be reached. We also consider systematic effects due to magnetic fields and vector light shifts and how they could be controlled.
Woody plant encroachment enhances soil infiltrability of a semiarid karst savanna
Authors: Leite Pedro A M , Wilcox Bradford P , McInnes Kevin J
Published: November 2020

Semiarid karst landscapes are often the source areas for regionally important groundwater supplies. Like savannas across the globe, these landscapes are experiencing an increase in woody plant cover—often referred to as woody plant encroachment. Although this phenomenon is commonly viewed as leading to increased transpiration and reduced groundwater recharge, this may not be true of all ecosystems. For example, in the Edwards Plateau region of central Texas—where the underlying geology is karst—dramatic increases in baseflows have occurred concurrently with the expansion of woody plants. It has been suggested that in this context woody plants, especially juniper (Juniperus spp.), are partially responsible for boosting recharge by improving soil infiltrability, but this hypothesis has not been systematically evaluated. Our study examined the effects of an important encroaching shrub (Redberry juniper) on soil infiltrability in the Edwards Plateau. We carried out a large number of infiltration tests to determine soil infiltrability and used a dye tracer followed by soil profile excavation to estimate the potential for deep percolation. Tests were performed at increasing distances under juniper shrubs of five size classes, ranging from young seedlings to mature shrubs. We found that in soils underlying shrubs, infiltrability was quintupled and percolation depth almost tripled compared with soils in intercanopy zones. Surprisingly, shrub size was not a significant factor. Even the soils beneath the smallest shrubs had much higher infiltrability than intercanopy soils, showing that these woody plants modify soil properties at very early stages. We also found that both infiltrability and percolation depth gradually increased with proximity to the trunk and showed a strong correlation with litter thickness. Our results provide support for the hypothesis that in semiarid karst landscapes, woody plant encroachment—especially the invasion of juniper—can play an important role in enhancing groundwater recharge by improving the soil infiltrability.
Clinical and Epidemiologic Evaluation of Inconclusive COVID-19 PCR Results Using a Quantitative Algorithm
Authors: Yang Shangxin , Stanzione Nicholas , Uslan Daniel Z , Garner Omai B , de St Maurice Annabelle
Published: November 2020

Objectives

The inconclusive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction (PCR) result causes confusion and delay for infection prevention precautions and patient management. We aimed to develop a quantitative algorithm to assess and interpret these inconclusive results.

Methods

We created a score-based algorithm by combining laboratory, clinical, and epidemiologic data to evaluate 69 cases with inconclusive coronavirus disease 2019 (COVID-19) PCR results from the Centers for Disease Control and Prevention (CDC) assay (18 cases) and the TaqPath assay (51 cases).

Results

We determined 5 (28%) of 18 (CDC assay) and 20 (39%) of 51 (TaqPath assay) cases to be false positive. Lowering the cycle threshold cutoff from 40 to 37 in the TaqPath assay resulted in a dramatic reduction of the false-positive rate to 14%. We also showed testing of asymptomatic individuals is associated with a significantly higher probability of having a false-positive result.

Conclusions

A substantial percentage of inconclusive SARS-CoV-2 PCR results can be false positive, especially among asymptomatic patients. The quantitative algorithm we created was shown to be effective and could provide a useful tool for clinicians and hospital epidemiologists to interpret inconclusive COVID-19 PCR results and provide clinical guidance when additional PCR or antibody test results are available.
Social Work, Disasters and Communities—Challenging the Boundaries of the Profession
Authors: Das Arpita
Published: November 2020

Disasters caused by natural phenomena are ubiquitous world over in terms of their occurrence. Myths and folklore are testament to this. The transition of natural phenomena into ‘natural’ disasters occurs only when humans are introduced. ‘Natural’ disasters have a social gradient to them, which differs vastly across societies. Epistemologically, disasters have been the forte of technocrats with social workers at best remaining at the fringes. This article is based on an empirical study undertaken with two communities who live in the flood affected Brahmaputra valley. It reveals a gap in the knowledge of the local realities—social, political, geographical resulting in grand and ineffective policy making. The current policies have a large imprint of the colonial with little being done in terms of developing alternate, localised and participatory methods of flood management. It demonstrates how the community’s efforts transcend a spectrum of stages moving from prevention and adaption to mitigation. For the Brahmaputra floods, the reality is extremely tenuous. Hence, it is not feasible for one knowledge system to understand the whole reality. Rather it needs to be acknowledged that multiple knowledge systems exist, and social workers need to be stakeholders in this process of knowledge creation and building of resilient communities.
Increased Mucosal Thrombin is Associated with Crohn’s Disease and Causes Inflammatory Damage through Protease-activated Receptors Activation
Authors: Motta Jean-Paul , Palese Simone , Giorgio Carmine , Chapman Kevin , Denadai-Souza Alexandre , Rousset Perrine , Sagnat David , Guiraud Laura , Edir Anissa , Seguy Carine , Alric Laurent , Bonnet Delphine , Bournet Barbara , Buscail Louis , Gilletta Cyrielle , Buret Andre G , Wallace John L , Hollenberg Morley D , Oswald Eric , Barocelli Elisabetta , Le Grand Sylvie , Le Grand Bruno , Deraison Celine , Vergnolle Nathalie
Published: November 2020

Background and Aims

Thrombin levels in the colon of Crohn’s disease patients have recently been found to be elevated 100-fold compared with healthy controls. Our aim was to determine whether and how dysregulated thrombin activity could contribute to local tissue malfunctions associated with Crohn’s disease.

Methods

Thrombin activity was studied in tissues from Crohn’s disease patients and healthy controls. Intracolonic administration of thrombin to wild-type or protease-activated receptor-deficient mice was used to assess the effects and mechanisms of local thrombin upregulation. Colitis was induced in rats and mice by the intracolonic administration of trinitrobenzene sulphonic acid.

Results

Active forms of thrombin were increased in Crohn’s disease patient tissues. Elevated thrombin expression and activity were associated with intestinal epithelial cells. Increased thrombin activity and expression were also a feature of experimental colitis in rats. Colonic exposure to doses of active thrombin comparable to what is found in inflammatory bowel disease tissues caused mucosal damage and tissue dysfunctions in mice, through a mechanism involving both protease-activated receptors -1 and -4. Intracolonic administration of the thrombin inhibitor dabigatran, as well as inhibition of protease-activated receptor-1, prevented trinitrobenzene sulphonic acid-induced colitis in rodent models.

Conclusions

Our data demonstrated that increased local thrombin activity, as it occurs in the colon of patients with inflammatory bowel disease, causes mucosal damage and inflammation. Colonic thrombin and protease-activated receptor-1 appear as possible mechanisms involved in mucosal damage and loss of function and therefore represent potential therapeutic targets for treating inflammatory bowel disease.
Evaluation of the Bidirectional Relations of Perceived Physical Fatigability and Physical Activity on Slower Gait Speed
Authors: Qiao Yujia (Susanna) , Gmelin Theresa , Renner Sharon W , Boudreau Robert M , Martin Sarah , Wojczynski Mary K , Christensen Kaare , Andersen Stacy L , Cosentino Stephanie , Santanasto Adam J , Glynn Nancy W
Published: November 2020

Background

Lower physical activity levels and greater fatigability contribute independently to slower gait speed in older adults. To fully understand the bidirectional relations between physical activity and fatigability, and to inform potential intervention strategies, we examined whether physical activity or fatigability explains more of the other factor’s association on slower gait speed.

Methods

Two generations (probands and offspring) of older adults (N = 2079, mean age 73.0 ± 10.0 years, 54.2% women, 99.7% White) enrolled in the Long Life Family Study were assessed at Visit 2 (2014–2017). Self-reported physical activity was measured with the Framingham Physical Activity Index and perceived physical fatigability using the Pittsburgh Fatigability Scale. Statistical mediation analyses were conducted separately by generation with linear mixed-effect models accounting for family relatedness and adjusted for demographics, health conditions, and field center.

Results

Greater perceived physical fatigability explained the association of lower physical activity on slower gait speed via a 22.5% attenuation of the direct association (95% confidence interval [CI]: 15.0%–35.2%) for the probands and 39.5% (95% CI: 22.8%–62.6%) for the offspring. Whereas lower physical activity explained the association of greater perceived fatigability on slower gait speed via a 22.5% attenuation of the direct association (95% CI: 13.4%–32.8%) for the probands and 6.7% (95% CI: 3.8%–15.4%) for the offspring.

Conclusions

Our findings suggest that the impact of greater perceived physical fatigability on the association between lower physical activity and slower gait speed differs between younger-old and middle-to-oldest-old adults, indicating perceived physical fatigability as a potential mediator in the disablement pathway.
High-density lipoprotein cholesterol and all-cause mortality by sex and age: a prospective cohort study among 15.8 million adults
Authors: Yi Sang-Wook , Park Se-Jun , Yi Jee-Jeon , Ohrr Heechoul , Kim Hyeongsu
Published: November 2020

Background

The associations between high-density lipoprotein cholesterol (HDL-C) levels and all-cause mortality are unclear in young adults (<45 years) and in Asian populations.

Methods

In total, 15 860 253 Korean adults underwent routine health examinations during 2009–10 and were followed until June 2018 for all-cause mortality. Hazard ratios (HRs) were calculated using Cox proportional hazard models.

Results

During a mean 8.4 years of follow-up, 555 802 individuals died. U-curve associations were found between HDL-C levels and mortality, irrespective of sex or age. The HDL-C ranges associated with the lowest mortality were 40–59 and 50–69 mg/dL (1.03–1.54 and 1.29–1.80 mmol/L) in men aged <65 and ≥65 years, respectively, and the corresponding ranges were 40–69 and 50–79 mg/dL (1.03–1.80 and 1.29–2.06 mmol/L) in women aged <45 and ≥45 years, respectively. For HDL-C ranges of 60–149 mg/dL (1.55–3.86 mmol/L), each 39 mg/dL (1 mmol/L) increase in HDL-C was associated with higher mortality [men: HR = 1.39; 95% confidence interval (CI) = 1.36–1.42; women: HR = 1.15, 95% CI = 1.11–1.18], adjusting for age. These positive associations were generally stronger at younger than older ages, whereas inverse associations for HDL-C ranges <60 mg/dL (1.55 mmol/L) were strongest in middle age (45–64 years). The U-curve associations were generally unchanged after adjustment for various confounders.

Conclusions

Korean adults showed U-curve associations of HDL-C with mortality, regardless of sex, and age. Younger adults had a lower optimal range and a stronger positive association with mortality than older adults in the high HDL-C range. Even moderately high HDL-C levels are not necessarily a sign of good health, especially in young adults.