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Evaluation of gravimetric sampler bias, effect on measured concentration, and proposal for the use of harmonised performance based dust sampler for exposure assessment

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International Journal of Mining Science and Technology 2019年第3期29卷 445-452页

作者： b.belle Anglo American Coal UNSW SydneyAustralia

The last three years has brought about alarming news of re-identification of coal worker’s pneumoconiosis(CWP)or‘black lung’in Australia after reporting nearly being absent for over five ***,the CWP statistics in South Africa(SA)are unverifiable,but certainly CWP has not been *** events have re-kindled the need for better understanding of the dust monitoring,performance of sampling devices,and compliance *** the last half century,gravimetric sampling has been the fundamental means for dust exposure monitoring using recognised respirable size-selective *** both South Africa and Australia,the gravimetric sampling technique in coal mines has been followed since 1988 and 1983 respectively using samplers of original Higgins-Dewell(HD)type *** paper provides the evaluation results of currently used South African and Australian gravimetric samplers compared against the original UK SIMPEDS‘true reference’*** results consistently suggested that the South African and Australian cyclones do not conform to the required size selective curve or even the‘true’reference *** results show that the currently used SA and Australian samplers showed a D50 sampling bias as high as 59%and 47%respectively against the size-selective ***,under the controlled laboratory coal dust test conditions measuring the same coal mine dust level in a chamber,the South African,Australian and UK standard SIMPEDS sampler were 7.87,9.79 and 6.71 mg/m3 respectively,which aligned with the sampling *** differences can in part be attributed to the‘un-auditable’inherent design and manufacturing quality,or unverifiable data on sizeselective sampling *** finding has significant implications towards exposure data collected over the last 25 years and their subsequent use in the arrival of the dose-response ***,it is strongly recommended that the harmonised use of‘true reference’SIMPEDS cyclone that meets the IS

关键词： Dust Respirable Sampling

Irreversibility investigation of Casson fluid flow in an inclined channel subject to a Darcy-Forchheimer porous medium:a numerical study

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Applied Mathematics and Mechanics(English Edition) 2021年第1期42卷 95-108页

作者： A.ROJA b.J.GIREESHA b.NAGARAJA Department of PG Studies and Research in Mathematics Kuvempu UniversityShankaraghattaShimoga 577451KarnatakaIndia

The heat transfer and entropy generation characteristics of the magnetohydrodynamic Casson fluid flow through an inclined microchannel with convective boundary conditions are ***,the effects of the viscous forces,Joule heating,heat source/sink,and radiation on the flow are taken into *** non-dimensional transformations are used to solve the governing ***,the reduced system is resolved by the fourth-fifth order Runge-Kutta-Fehlberg method along with the shooting *** effects of different physical parameters on the heat transfer and entropy generation are discussed in detail through *** the perspective of numerical results,it is recognized that the production of entropy can be improved with the Joule heating,viscous dissipation,and convective heating *** is concluded that the production of entropy is the maximum with increases in the Casson parameter,the angle of inclination,and the Hartmann *** the Reynolds number and the radiation parameter cause the dual impact on entropy generation.

关键词： inclined channel Casson fluid magnetism radiation entropy generation bejan number

How relevant are engineering samples in the management of personal dust exposure?

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International Journal of Mining Science and Technology 2018年第4期28卷 697-703页

作者： b.belle Anglo American Coal BrisbaneQueenslandAustralia Department of Mining Engineering UNSWSydneyNSW 2052Australia

A directive, legislated by the South African Department of Minerals and Energy(DME) in 1997, was introduced to reduce the dust exposures of continuous miner(CM) operators to below 5 mg/m3, when measured at the operator's cab position. The focus of this paper is to review the effectiveness of observing this rule for almost two decades and discuss industry perceptions arising from the application of this rule. The results have demonstrated that the engineering sample cannot predict the personal shift dust exposure of a CM operator. Therefore, it is recommended that the engineering sampling, as currently practiced,should be reviewed with the objective to discontinue and replace it by the approved PDM3700 realtime dust monitor.

关键词： Continuous miner (CM) Dust exposure Personal Engineering sample

Identification of the normal and abnormal glow discharge modes in a neon-xenon gas mixture at low pressure

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Plasma Science and Technology 2018年第11期20卷 70-75页

作者： b HECHELEF A bOUCHIKHI University of Saida Faculty of Technology Department of Electrical Engineering Saida 20000 Algeria

In this paper, we focused on the identification of the normal and abnormal glow discharge modes in a neon-xenon gas mixture at low pressure. We considered four gas mixtures： 90%Ne-10%Xe, 80%Ne-20%Xe, 70%Ne-30%Xe and 50%Ne-50%Xe at 1.5 Torr. The range of the gap voltage is 150-500 V. A one-dimensional fluid model with multiple species was used in this work, and the metastable state of the atoms as well as the radiation effects were integrated into the model too. The input data changed for each percentage in the gas mixture, and was calculated by bOLSIG＋ software. The parameters of particle transport and their rate coefficients strictly depend on the mean electron energy. The results show that the neon ion density is negligible compared to the xenon ion density, mostly in the case of 50%Ne-50%Xe.

关键词： gas mixtures boltzmann's equation Poisson's equation blanc's law two-order fluid model

Oscillating multidromion excitations in higher-dimensional nonlinear lattice with intersite and external on-site potentials using symbolic computation

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Chinese Physics b 2014年第1期23卷 98-107页

作者： b. Srividya louiskavitha@yahoo.co.in Department of Chemistry Periyar University Salem 636 011 India

We show by an extensive method of quasi-discrete multiple-scale approximation that nonlinear multi-dimensional lattice waves subjected to intersite and external on-site potentials are found to be governed by （N＋ 1 ）-dimensional nonlinear Schr6dinger （NLS） equation. In particular, the resonant mode interaction of （2＋l）-dimensional NLS equation has been identified and the theory allows the inclusion of transverse effect. We apply the exponential function method to the （2＋ I ）- dimensional NLS equation and obtain the class of soliton solutions with a purely algebraic computational method. Notably, we discuss in detail the effects of the external on-site potentials on the explicit form of the soliton solution generated recursively. Under the action of the external on-site potentials, the model presents a rich variety of oscillating multidromion patterns propagating in the system.

关键词： solitons partial differential equations lattice dynamics exact solutions

Pattern Analysis and Regressive Linear Measure for botnet Detection

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Computer Systems Science & Engineering 2022年第10期43卷 119-139页

作者： b.Padmavathi b.Muthukumar Department of Computer Science and Engineering Sathyabama Institute of Science and TechnologyChennaiIndia Department of Computer Science and Engineering Easwari Engineering CollegeChennaiIndia Department of Computer Science and Engineering United Institute of TechnologyCoimbatoreIndia

Capturing the distributed platform with remotely controlled compromised machines using botnet is extensively analyzed by various ***,certain limitations need to be addressed *** provisioning of detection mechanism with learning approaches provides a better solution more broadly by saluting multi-objective *** bots’patterns or features over the network have to be analyzed in both linear and non-linear *** linear and non-linear features are composed of high-level and low-level *** collected features are maintained over the bag of Features(boF)where the most influencing features are collected and provided into the classifier ***,the linearity and non-linearity of the threat are evaluated with Support Vector Machine(SVM).Next,with the collected boF,the redundant features are eliminated as it triggers overhead towards the predictor ***,a novel Incoming data Redundancy Elimination-based learning model(RedE-L)is built to classify the network features to provide robustness towards botNets *** simulation is carried out in MATLAb environment,and the evaluation of proposed RedE-L model is performed with various online accessible network traffic dataset(benchmark dataset).The proposed model intends to show better tradeoff compared to the existing approaches like conventional SVM,C4.5,RepTree and so ***,various metrics like Accuracy,detection rate,Mathews Correlation Coefficient(MCC),and some other statistical analysis are performed to show the proposed RedE-L model's *** F1-measure is 99.98%,precision is 99.93%,Accuracy is 99.84%,TPR is 99.92%,TNR is 99.94%,FNR is 0.06 and FPR is 0.06 respectively.

关键词： botNet threat intrusion features linearity and non-linearity redundancy regressive linear measure classification redundancy eliminationbased learning model

On the pressure and stress singularities induced by steady flows of a pair of nonmiscible,incompressible,viscous fluids contacting a wall with slip

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Acta Mechanica Sinica 2020年第3期36卷 686-691页

作者： G.b.Sinclair Department of Mechanical Engineering Louisiana State UniversityBaton RougeLA 70803USA

An earlier asymptotic analysis identified the flow-induced power and log singularities present when two nonmiscible,incompressible,viscous fluids contact a wall with no slip *** a parallel asymptotic analysis identifies such singularities in pressures and stresses when slip is *** the singularity exponents for the two types of contact conditions are similar,the angles of interface impingement that have either power or log singularities are usually quite distinct.

关键词： Incompressible viscous fluids Slip conditions Fluid-structure interactions Singular stresses

The synthesis of polymers of intrinsic microporosity (PIMs)

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Science China Chemistry 2017年第8期60卷 1023-1032页

作者： Neil b.McKeown School of Chemistry University of Edinburgh David Brewster Road Edinburgh EH9 3F J U

Polymers of intrinsic microporosity （PIMs） are a class of porous organic polymer （POP） that form microporous solids due to the inefficient packing of their rigid and contorted macromolecular chains. In contrast to other types of POP, PIMs are not comprised of a network of cross-linked covalent bonds so that they can be dissolved in organic solvents and processed into robust films, coatings or fibres. Here, over twelve years＇ accumulated research on the synthesis of PIMs is reviewed. To date, three types of polymerisation reaction have been used successfully to prepare PIMs of sufficient molecular mass to form robust self-standing films. These involve the formation of dibenzodioxin, Tr6ger＇s base and imide linkages between monomeric units. This rapid development of synthetic methods for preparing PIMs has been driven by their rich potential for numerous diverse applications and this synergistic relationship between synthesis and functionality is set to continue.

关键词： polymers of intrinsic microporosity synthesis porous organic polymers

Non-native plant species richness and influence of greenhouses and human populations in the conterminous United States

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Ecological Processes 2023年第1期12卷 388-401页

作者： brice b.Hanberry USDA Forest Service Rocky Mountain Research StationRapid CitySD 57702USA

background One issue in invasive plant ecology is identification of the factors related to the invasion process that increase number of non-native *** invasion by non-native species increases,so does the probability that some non-native species will become harmful,or classified as invasive species,which disrupt natural ecosystems with attendant economic and social costs.I quantified patterns of how non-native species richness varied with vegetation types and human *** evaluate the relative importance of different predictor variables for invasion pathways in the conterminous United States,I modeled non-native plant species richness by county compared to current and historical human populations;greenhouses and nurseries;railroads,pipelines,transmission lines,and oil and gas wells;and land covers of impervious surface,development intensity categories,agriculture,and vegetation types.I also modeled these variables within vegetation types,excluding vegetation *** To summarize patterns,non-native plant species richness increased from 72 to 200 with increasing human population density *** and forest land use mosaics had the greatest mean number of non-native plant species,ranging from 121 to 166,whereas grasslands and grassland mosaics had the least number of non-native plant species,about *** modeling variable importance,all combined variables had R^(2)values of 56%(random forests regressor)and 54%(cubist regressor)for predictions of withheld observations of non-native plant species rich-ness,with greenhouse density and percent forestlands as most influential *** variables of greenhouses(R^(2)=29%),historical and current human populations(R^(2)=27%and 23%),impervious surface(25%),and medium intensity development(23%)were most associated with non-native plant species *** vegetation types,greenhouse and historical human population densities were influential variables particularly in forestlands,shrubland

关键词： Agriculture Energy Forest Grassland Invasive Propagule Rural Transport Urban

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