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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

Investigation of the Transition Reaction of Tobermorite to Xonotlite under Influence of Additives

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Advances in Chemical Engineering and Science 2015年第2期5卷 197-214页

作者： Andrea hartmann David Schulenberg Josef-Christian buhl Institute of Mineralogy Hannover University Hannover Germany

The objective of the present work was to investigate the transition reaction of the calcium silicate hydrate tobermorite into xonotlite under influence of additives. Tobermorite is the main binding agent in steam hardened building materials and the appearance of xonotlite indicates the progress of hardening and an overcuring of the material. Hydrothermal experiments under addition of sucrose, calcium formate and calcium chloride dihydrate to the main components quartz and lime were done using temperatures of 220°C and a reaction time of 40.5 h. All experiments were performed with powders as well as with pressed educts. The products of all syntheses were analyzed with XRD, SEM/EDX and FTIR. The references as well as the syntheses with calcium chloride dihydrate led to the formation of 11 Å tobermorite and xonotlite. The former showed the best results and even synthesis with pressed educts and calcium chloride dihydrate revealed an accelerating effect of the additive. In contrast syntheses with sucrose had the worst reactivity and led to the formation of calcite beside the CSH-phase scawtite. The additive calcium formate was only slightly oppressing the crystallization of tobermorite and favouring the formation of xonotlite. Syntheses with pressed pellets and sucrose or calcium formate showed generally worse results.

关键词： CSH-Phases Tobermorite Xonotlite Additives Retarder Accelerator

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

Piling up multidecker pyrgos[n]cages as antibacterial materials

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Science China Materials 2025年第1期 314-316页

作者： Miguel A.Liuzzi-Vaamonde Jackson b.Lancaster Samantha A.Mason Yuanning Feng Department of Chemistry and biochemistry The University of Oklahoma

The development of antibiotics is regarded as one of the most significant scientific advances in modern medicine. before the commercialization of antibiotics, infectious diseases were catastrophic throughout history [1]. Penicillin was used to treat serious infections in the 1940s, but unfortunately, with the introduction of antibiotics came the emergence of antibiotic resistance [2,3]. Evolved and adapted methicillin-resistant Staphylococcus aureus (MRSA) strains are presently impacting community and healthcare systems across the globe [4].

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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

Synthesis and Structural Characterization of CSH-Phases in the Range of C/S = 0.41 - 1.66 at Temperatures of the Tobermorite Xonotlite Crossover

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Journal of Materials Science and Chemical Engineering 2015年第11期3卷 39-55页

作者： Andrea hartmann David Schulenberg Josef-Christian buhl Institut fü r Mineralogie LUH Hannover Germany Institut fü r baustoffe Bauphysik und Bauchemie TUHH Hamburg Germany

Calcium-Silicate-Hydrate-phases (CSH-phases) are important binding agents of building materials. The synthesis of CSH phases and their structural characterization was done to investigate the crystallization in dependence of an increasing CaO/SiO2 ratio (C/S ratios) from 0.41 up to 1.66 at temperatures in the crossover region of tobermorite to xonotlite (180℃ and 230℃). Parallel runs with the same C/S ratio but on the one hand with constant mass of quartz and variation of lime and on the other hand under reverse conditions (constant mass of lime but variable amounts of quartz) were performed at both temperatures. The aim was to clarify the connections of crystallization mechanism and kinetics of phase formation with structure, crystallinity and morphology of the CSH’s in the mentioned C/S ratio for both temperatures in the tobermorite-xonotlite crossover region. The parallel experiments with different mass ratios of the educts are important to study the influence of time evaluation of supersaturation within the solution under the peculiarities of the retrograde solubility of lime but accelerated solubility of quartz. The products were characterized by XRD, SEM/EDX, FTIR and 29Si MAS NMR spectroscopy (using the Q-site nomenclature [1]). The experiments could clarify some important connections of crystallization process and the reaction pathway.

关键词： CSH-Phases Tobermorite Xonotlite C/S Ratio 29Si MAS NMR Spectroscopy

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实践中的PROLOG

小型微型计算机系统 1984年第4期 56-66页

作者： blint DMLKI Péter SZEREDI ,赖少庆

近来,作为解题系统大有作为的工具,PROLOG正越来越风行。PROLOG也可以看作是对某些类型的应用问题的实际可用的程序设计语言。为此,需要其工作实现,以满足程序执行的效率,语言功能的可扩充性,规范程序设计(如模块化设计)工具的引进,程... 详细信息

近来,作为解题系统大有作为的工具,PROLOG正越来越风行。PROLOG也可以看作是对某些类型的应用问题的实际可用的程序设计语言。为此,需要其工作实现,以满足程序执行的效率,语言功能的可扩充性,规范程序设计(如模块化设计)工具的引进,程序开发环境的有效利用等方面的要求,文中介绍的MPROLOG系统即可看成是实现大多数这些要求的一个尝试。

关键词：内部谓词 PROLOG 程序设计语言程序 ALGOL语言