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Distortions in focusing laser pulses due to spatio-temporal couplings:an analytic description

High Power Laser Science and Engineering 2024年第3期12卷 20-40页

作者： Klaus Steiniger Fabia Dietrich Daniel Albach Michael Bussmann Arie Irman Markus Loeser richard Pausch Thomas Püschel Roland Sauerbrey Susanne Schöbel Ulrich Schramm Mathias Siebold Karl Zeil Alexander Debus Helmholtz-Zentrum Dresden-Rossendorf DresdenGermany CASUS-Center for Advanced Systems Understanding GörlitzGermany Technische Universität Dresden DresdenGermany

In ultra-short laser pulses,small changes in dispersion properties before the final focusing mirror can lead to severe pulse distortions around the focus and therefore to very different pulse properties at the point of laser±matter interaction,yielding unexpected interaction *** mapping between far-and near-field laser properties intricately depends on the spatial and angular dispersion properties as well as the focal *** a focused Gaussian laser pulse under the influence of angular,spatial and group-delay dispersion,we derive analytical expressions for its pulse-front tilt,duration and width from a fully analytic expression for its electric field in the time±space domain obtained with scalar diffraction *** expression is not only valid in and near the focus but also along the entire propagation distance from the focusing mirror to the *** relating angular,spatial and group-delay dispersion before focusing at an off-axis parabola,where they are well measurable,to the respective values in the pulse’s focus are obtained by a ray tracing ***,these formulas are used to show in example setups that the pulse-front tilts of lasers with small initial dispersion can become several tens of degrees larger in the vicinity of the focus while being small directly in the *** formulas derived here provide the analytical foundation for observations previously made in numerical *** numerically simulating Gaussian pulse propagation and measuring properties of the pulse at distances several Rayleigh lengths off the focus,we verify the analytic expressions.

关键词： group-delay dispersion pulse-front tilt spatio-temporal couplings third-order dispersion ultra-short laser pulses

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Beyond cotton and polyester: An evaluation of emerging feedstocks and conversion methods for the future of fashion industry

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Journal of Bioresources and Bioproducts 2024年第2期9卷 130-159页

作者： Ryen M.Frazier Keren A.Vivas Ivana Azuaje Ramon Vera Alonzo Pifano Naycari Forfora Hasan Jameel Ericka Ford Joel J.Pawlak richard Venditti Ronalds Gonzalez Department of Forest Biomaterials North Carolina State UniversityRaleighNC 27695USA Department of Textile Engineering Chemistry and ScienceThe Nonwovens InstituteNorth Carolina State UniversityRaleighNC 27695USA

As the global population grows,the demand for textiles is increasing ***,this puts immense pressure on manufacturers to produce more *** synthetic fibers can be pro-duced cheaply,they have a negative impact on the *** the other hand,fibers from wool,sisal,fique,wood pulp(viscose),and man-made cellulose fibers(MMCFs)from cotton can-not alone meet the growing fiber demand without major stresses on land,water,and existing markets using these *** a greater emphasis on transparency and circular economy practices,there is a need to consider natural non-wood alternative sources for MMCFs to supple-ment other fiber ***,introducing new feedstocks with different compositions may require different biomass conversion ***,based on existing work,this review ad-dresses the technical feasibility of various alternative feedstocks for conversion to textile-grade ***,alternative feedstocks are introduced,and then conventional(dissolving pulp)and emerging(fibrillated cellulose and recycled material)conversion technologies are evaluated to help select the most suitable and promising processes for these emerging alternative sources of *** is important to note that for alternative feedstocks to be adopted on a meaningful scale,high biomass availability and proximity of conversion facilities are critical *** North America,soybean,wheat,rice,sorghum,and sugarcane residues are widely available and most suitable for conventional conversion through various dissolving pulp production methods(pre-hydrolysis kraft,acid sulfite,soda,SO2-ethanol-water,and potassium hydroxide)or by emerging cellulose fibrillation *** dissolving pulp conversion is well-established,fibrillated cel-lulose methods could be beneficial from cost,efficiency,and environmental ***,the authors strongly encourage more work in this growing research ***,conducting thorough cost and sustainability assessment

关键词： Non-wood Residue Regenerated cellulose Dissolving pulp Man-made cellulose fiber Apparel textile

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Innuendoes of Sterilisation Drilling in Surface Mining Operations—A Case Study

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International Journal of Geosciences 2024年第5期15卷 458-477页

作者： richard Gyebuni Festus Kunkyin-Saadaari Isaac Ekow Anaman Department of Mining Engineering University of Mine and Technology Tarkwa Ghana Mining Engineering Department Ghana Manganese Company Tarkwa Ghana

Surface mining operations play a crucial role in meeting the world’s increasing demand for mineral resources for the advancement of technology and debauched expansion of economies. The search for and exploitation of these mineral resources are therefore important for the sustainability of the mineral extraction industry. To this end, efficient mine planning must incorporate sterilisation drilling and effective waste rock management principles in the search and exploitation of these minerals. In this article, sterilisation drilling is being reviewed vis-a-vis the establishment of waste and tailings dump locations, backfilling of open pit excavations and mine closure giving critical attention to the minerals and mining laws of Ghana. Subsequently, a detailed case study of a surface mining operation that successfully incorporated sterilisation drilling in determining waste dump location in its mine planning process has been presented in this study. The findings indicate that the proposed waste dump location could present a potential mining prospect in the future based on enhanced milling capacity/technology and improved mineral commodity price;underscoring the significance of sterilization drilling in the sustainability of the mining industry.

关键词： Sterilisation Exploration Backfilling Waste Dump Cutoff Grade

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Full Dynamic Model for Liquid Sloshing Simulation in Cylindrical Tank Shape

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World Journal of Mechanics 2024年第4期14卷 55-72页

作者： Omar Noui Mohamed Bouazara Marc J. richard Department of Applied Science University of Quebec at Chicoutimi Chicoutimi Canada Department of Mechanical Engineering Laval University Quebec Canada

This study presents a comprehensive full dynamic model designed for simulating liquid sloshing behavior within cylindrical tank structures. The model employs a discretization approach, representing the liquid as a network of interconnected spring-damper-mass systems. Key aspects include the adaptation of liquid discretization techniques to cylindrical lateral cross-sections and the calculation of stiffness and damping coefficients. External forces, simulating various vehicle maneuvers, are also integrated into the model. The resulting system of equations is solved using Maple Software with the Runge-Kutta-Fehlberg method. This model enables accurate prediction of liquid displacement and pressure forces, offering valuable insights for tank design and fluid dynamics applications. Ongoing refinement aims to broaden its applicability across different liquid types and tank geometries.

关键词： Fluid-Structure Interaction Equivalent Mechanical Model Liquid Discretization Spring-Mass Model Spring-Mass Network Liquid Simulation

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Research surveys and their evolution:Past,current and future uses in healthcare

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World Journal of Methodology 2024年第4期14卷 91-95页

作者： Michael Colwill richard Pollok Andrew Poullis Department of Gastroenterology St George's University Hospital NHS Foundation TrustLondon SW170QTUnited Kingdom

Research surveys are believed to have originated in antiquity with evidence of them being performed in ancient Egypt and *** the past century,their use has grown significantly and they are now one of the most frequently employed research methods including in the field of *** validation techniques and processes have allowed researchers to broaden the scope of qualitative data they can gather through these surveys such as an individual’s views on service quality to nationwide surveys that are undertaken regularly to follow healthcare *** article focuses on the evolution and current utility of research surveys,different methodologies employed in their creation,the advantages and disadvantages of different forms and their future use in healthcare *** also review the role artificial intelligence and the importance of increased patient participation in the development of these surveys in order to obtain more accurate and clinically relevant data.

关键词： Research surveys Methodology Sampling Artificial intelligence

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Low-temperature catalytic methane deep oxidation over sol-gel derived mesoporous hausmannite (Mn_(3)O_(4)) spherical particles

ChemPhysMater

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ChemPhysMater 2024年第3期3卷 329-340页

作者： Patrick Ndouka Ndouka Stephane Kenmoe Jacques richard Mache Elie Acayanka Dick Hartmann Douma Ralph Gebauer Patrick Mountapmbeme Kouotou Department of Chemistry Faculty of SciencesUniversity of MarouaP.O.Box 814 MarouaCameroon Department of Theoretical Chemistry University of Duisburg-EssenD-45141 EssenGermany Department of Mining Engineering School of Geology and Mining EngineeringUniversity of NgaoundéréP.O.Box 115 MeigangaCameroon Department of Inorganic Chemistry Faculty of ScienceUniversity of YaoundéIP.O.Box 812 YaoundéCameroon Groupe de Simulations Numériques en Magnétisme et Catalyse Facultédes Sciences et TechniquesUniversitéMarien NgouabiB.P.69 BrazzavilleCongo The Abdus Salam International Centre for Theoretical Physics(ICTP) 34151 TriesteItaly National Advanced School of Engineering of Maroua University of MarouaP.O.Box 46 MarouaCameroon Higher Institute of Agriculture WoodWater and EnvironmentUniversity of EbolowaP.O.Box 118 EbolowaCameroon

In this study,Mn_(3)O_(4) spherical particles(SPs)were synthesized by the sol-gel process,after which they were thermally annealed at 400℃,and comprehensively characterized.X-ray Diffraction(XRD)revealed that Mn_(3)O_(4) exhibited a tetragonal spinel structure,and Fourier transformed infrared(FTIR)spectroscopy identified surfaceadsorbed functional *** electron microscopy(SEM)and the specific surface area analyses by Brunauer−Emmett−Teller(BET)revealed a porous,homogeneous surface composed of strongly agglomerated spherical grains with an estimated average particle size of∼35 nm,which corresponded to a large specific surface area of∼81.5 m^(2)/g.X-ray photoelectron spectroscopy(XPS)analysis indicated that Mn_(3)O_(4) was composed of metallic cations(Mn^(4+),Mn_(3)+,and Mn^(2+))and oxygen species(O_(2)−,OH−and CO_(3)2−).The optical bandgap energy is∼2.55 *** of the catalytic performance of the Mn_(3)O_(4) SPs indicated T90 conversion of CH4 to CO_(2) and H2O at 398℃ for gas hourly space velocity(GHSV)of 72000 mL^(3) g^(−1) h^(−1).This observed performance can be attributed to the cooperative effects of the smallest spherical grain size with a mesoporous structure,which is responsible for the larger specific surface area and available surface-active oxygenated *** cooperative effect of the good reducibility,higher ratio of active species(OLat/OAds),and results of density functional theory(DFT)calculations suggested that the total oxidation of CH4 over the mesoporous Mn_(3)O_(4) SPs might take place via a two-term process in which both the Langmuir−Hinshelwood and Mars−van Krevelen mechanisms are cooperatively involved.

关键词： Sol-gel Manganese oxide Catalytic oxidation Methane Langmuir−Hinshelwood mechanism Mars−van Krevelen route Two−term process

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Biobanks and biomarkers:Their current and future role in biomedical research

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World Journal of Methodology 2024年第4期14卷 77-83页

作者： Michael Colwill Samantha Baillie richard Pollok Andrew Poullis Department of Gastroenterology St George's University Hospital NHS Foundation TrustLondon SW170QTUnited Kingdom

The importance and utility of biobanks has increased exponentially since their inception and *** used as part of translational research,they now contribute over 40%of data for all cancer research papers in the United States of America and play a crucial role in all aspects of *** classification systems exist but a simplified approach is to either classify as population-based or disease-oriented *** historically publicly funded institutions,there has been a significant increase in industry funded entities across the world which has changed the dynamic of biobanks offering new possibilities but also new *** face legal questions over data sharing and intellectual property as well as ethical and sustainability questions particularly as the world attempts to move to a low-carbon *** collaboration is required to address some of these challenges but this in itself is fraught with complexity and *** review will examine the current utility of biobanks in the modern healthcare setting as well as the current and future challenges these vital institutions face.

关键词： Biobanks Biomarkers Biomedical research Research methodology Research ethics

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A Bayesian hierarchical model for the inference between metal grade with reduced variance:Case studies in porphyry Cu deposits

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Geoscience Frontiers 2024年第2期15卷 304-314页

作者： Yufu Niu Mark Lindsay Peter Coghill richard Scalzo Lequn Zhang CSIRO Mineral Resources Lucas HeightsNew South Wales 2234Australia Mineral Exploration Cooperative Research Centre Centre for Exploration TargetingSchool of Earth ScienceThe University of Western AustraliaPerthWA 6009Australia ARC centre for Data Analytics for Resources and Environments(DARE) Perth and SydneyAustralia CSIRO Mineral Resources Australian Resources Research CentreWA 6151Australia CSIRO Data61 ClaytonVIC 3168Australia

Ore sorting is a preconcentration technology and can dramatically reduce energy and water usage to improve the sustainability and profitability of a mining *** porphyry Cu deposits,Cu is the primary target,with ores usually containing secondary‘pay’metals such as Au,Mo and gangue elements such as Fe and *** to sensing technology limitations,secondary and deleterious materials vary in correlation type and strength with Cu but cannot be detected simultaneously via magnetic resonance(MR)ore *** the relationships between Cu and other elemental abundances is particularly critical for mineral *** variations in metal grade relationships occur due to the transition into different geological *** raises two questions-how to define these geological domains and how the metal grade relationship is influenced by these geological *** this paper,linear relationship is assumed between Cu grade and other metal *** applies a Bayesian hierarchical(partial-pooling)model to quantify the linear relationships between Cu,Au,and Fe grades from geochemical bore core *** hierarchical model was compared with two other models-‘complete-pooling’model and‘nopooling’*** blocks were split based on spatial domain to construct hierarchical *** bore core data records metal grades measured from laboratory assay with spatial coordinates of sample *** case studies from different porphyry Cu deposits were used to evaluate the performance of the hierarchical *** chain Monte Carlo(MCMC)was used to sample the posterior *** results show that the Bayesian hierarchical model dramatically reduced the posterior predictive variance for metal grades regression compared to the no-pooling *** addition,the posterior inference in the hierarchical model is insensitive to the choice of *** data is wellrepresented in the posterior which indicates a robust *** results show that the spatial dom

关键词： Bayesian hierarchical model Porphyry Cu deposit Ore sorting Metal grade Linear regression

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Modeling Solid Waste Minimization Performance at Source in Dar es Salaam City, Tanzania

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Journal of Geoscience and Environment Protection 2024年第9期12卷 17-32页

作者： Abdon Salim Mapunda richard Joseph Kimwaga Shaaban Ally Kassuwi Department of Integrated Water Resources Engineering University of Dar es Salaam Dar es Sa-laam Tanzania Department of Molecular Biology and Biotechnology University of Dar es Salaam Dar es Salaam Tanzania

Municipal solid waste generation is strongly linked to rising human population and expanding urban areas, with significant implications on urban metabolism as well as space and place values redefinition. Effective management performance of municipal solid waste management underscores the interdisciplinarity strategies. Such knowledge and skills are paramount to uncover the sources of waste generation as well as means of waste storage, collection, recycling, transportation, handling/treatment, disposal, and monitoring. This study was conducted in Dar es Salaam city. Driven by the curiosity model of the solid waste minimization performance at source, study data was collected using focus group discussion techniques to ward-level local government officers, which was triangulated with literature and documentary review. The main themes of the FGD were situational factors (SFA) and local government by-laws (LGBY). In the FGD session, sub-themes of SFA tricked to understand how MSW minimization is related to the presence and effect of services such as land use planning, availability of landfills, solid waste transfer stations, material recovery facilities, incinerators, solid waste collection bins, solid waste trucks, solid waste management budget and solid waste collection agents. Similarly, FGD on LGBY was extended by sub-themes such as contents of the by-law, community awareness of the by-law, and by-law enforcement mechanisms. While data preparation applied an analytical hierarchy process, data analysis applied an ordinary least square (OLS) regression model for sub-criteria that explain SFA and LGBY;and OLS standard residues as variables into geographically weighted regression with a resolution of 241 × 241 meter in ArcMap v10.5. Results showed that situational factors and local government by-laws have a strong relationship with the rate of minimizing solid waste dumping in water bodies (local R square = 0.94).

关键词： Modeling Solid Waste Minimization Dar es Salaam City Ordinary Least Square (OLS) Regression Model Situation Factors Local Government by Laws

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Chemical Determination of Base Status Metals in Soil Sediments and Particulate Matter in Wellington Industrial Estate Location

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Open Journal of Applied Sciences 2024年第5期14卷 1338-1352页

作者： richard Tamba Simbo Jerry Yeke Paye Fayia Francis Nyuma Department of Chemistry School of Basic Sciences Njala University Freetown Sierra Leone Department of Science and Mathematics College of Arts and Sciences William V.S. Tubman University Harper Liberia Department of Fisheries and Science Thomas J.R Faulkner College of Science and Technology University of Liberia Monrovia Liberia

This research study explored the levels of base status metals in soil sediments and particulate matter in the wellington industrial estate location;the main objectives were to: 1) determine sodium and potassium, 2) determine calcium and magnesium, 3) determine available iron. The following hypotheses were put forward;H0a: there is no significant difference in the concentration levels between Ca and Mg in the study area, H1a: there is significant difference in the concentration levels between Ca and Mg in the study area, H0b: there is no significant difference in the concentration levels between Na and K in the study area, H1b: there is significant difference in the concentration levels between Na and K in the study area. Six locations were used to collect samples with the aid of scoop and gravel free auger (at varying depths of 0 - 5 cm and 5 - 10 cm) which are Wellington Industrial Estate Area 1 (WIEL 1), (WIEL 2), (WIEL 3), (WIEL 4), (WIEL 5), (WIEL 6);the samples were given laboratory treatment. Flame photometer, EDTA, and Spectrophotometer were used in the determinations of sodium and potassium, calcium and magnesium, and available iron respectively. The results indicated that levels of potassium were in medium range (moderately high);sodium levels were generally low when compared to Brook’s classification table. Levels of calcium were generally low and those of magnesium were moderate based on Brook’s table of classification. Levels of available iron which fall within the range of Quijano-Guerta (2003) were high;this implies such levels can lead to toxicity. In all locations, there was decrease in the levels of each metal in the samples with (5 - 10 cm) depth.

关键词： Deposition Environment Particulate Sediment Toxicity

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