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Seasonal size-segregated PM10 and PAH concentrations in a rural area of.sugarcane agriculture versus a coastal urban area in Southeastern f.orida, USA

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Particuology 2016年第5期14卷 52-59页

作者： Orhan Sevimoglu Wolf.ang f. Rogge Department of.Civil and Environmental Engineering Florida International University 10555 W. Flagier Street Miami FL 33174 USA School of.Engineering and Sierra Nevada Research Institute University of California at Merced 5200 North Lake Road Merced CA 95343 USA

Airborne particulate matter （PM） is of.health and environmental concern not only in highly urbanized areas, but also in rural areas that are used f.r intensive agricultural purposes, In this study, PM size- segregated samples were collected simultaneously f.r 12 months in a small town （Belle Glade, f.orida）, which is the center of.a vast sugarcane growing area and at Delray Beach, a coastal city in Palm Beach County, f.orida. During the winter sampling period, when sugarcane f.liage is burned just bef.re harvest- ing to reduce the amount of.plant matter to be handled, PM10 levels were 50% or higher than otherwise measured, indicating that sugarcane harvesting and processing is a major local source f.r PM10. f.r the rest of.the year, PM10 levels at both sites are similar, suggesting that ambient PM levels at both sites are impacted by the major urban centers in Southern f.orida. During late July and early August, the PM10 levels at both sites were substantially elevated and revealed the typical red-brownish color of.Saharan dust. This has been reported to occur f.equently with suitable meteorological conditions over the Atlantic Ocean coupled with a Sahara dust storm event. During the sugarcane harvesting season at Belle Glade, the concentrations of.PAHs associated with PM10 were up to 15 times higher than those measured during the summer growing season, indicating a substantially higher exposure of.the rural population to these of.en mutagenic and carcinogenic compounds.

关键词： Size segregated ambient particles PM10 PAHs Biomass burning Rural versus urban Saharan dust

Prof.le and Secondary f.ow Losses in a High-Lif. LPT Blade Cascade at Dif.erent Reynolds Numbers under Steady and Unsteady Inf.ow Conditions

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Journal of.Thermal Science 2012年第6期21卷 483-491页

作者： Satta f. Simoni D. Ubaldi M. Zunino P. Bertini f. DIMSET-Università di Genova Via Montallegro 1I-16145 GenovaItaly Avio S.p.A. Viale I Maggio 56I-10040 Rivalta(TO)-Italy

The aerodynamic f.ow f.eld downstream of.a Low-Pressure High-Lif.(HL)turbine cascade has been experimentally investigated f.r dif.erent Reynolds numbers under both steady and unsteady inf.ows,in order to analyse the cascade perf.rmance under real engine operating *** Reynolds number has been varied in the range 100000f.cruise and take-of./landing conditions,*** ef.ects induced by the incoming wakes at the reduced f.equency f.=0.62 on both prof.le and secondary f.ow losses have been *** pressure,velocity and secondary kinetic energy distributions at the downstream tangential plane have been measured by means of.a miniaturized 5-hole *** quantities provide inf.rmation on both blade wake and secondary f.ow structures(passage and horse-shoe vortices).The analysis of.the results allows the evaluation of.the aerodynamic perf.rmance of.the HL f.ont-loaded blade in terms of.both prof.le and secondary losses.

关键词： prof.le losses secondary f.ow losses high-lif. prof.es unsteady inf.ow LPT blade.

Approaching nuclei through multiple perspectives and diverse models： Patterns, symmetries, interactions

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f.ontiers of.physics 2018年第6期13卷 29-38页

作者： R. f. Casten Wright Nuclear Structure Laboratory Yale University New Haven CT 06520 USA Michigan State University- f.IB East Lansing MI USA

Nuclei are complex objects yet display remarkable simplicities and regular patterns. The study of.these and their origins has long been one of.the twin pillars of.nuclear structure research. We will discuss the behavior of.atomic nuclei f.om this point of.view. A key element will be the advantages of.looking at the same data f.om dif.erent perspectives and of.inter-relating these perspectives.

关键词： nuclear structure simple patterns and symmetries diverse perspectives and models emergence of.collectivity residual interactions

Prediction of.Soil Depth f.om Digital Terrain Data by Integrating Statistical and Visual Approaches

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Pedosphere 2010年第3期20卷 361-367页

作者： f. M. ZIADAT International Center f.r Agricultural Research in the Dry Areas (ICARDA) P.O. Box 5466Aleppo (Syria)

Inf.rmation about the spatial distribution of.soil attributes is indispensable f.r many land resource management applications; however, the ability of.soil maps to supply such inf.rmation f.r modern modeling tools is questionable. The objectives of.this study were to investigate the possibility of.predicting soil depth using some terrain attributes derived f.om digital elevation models （DEMs） with geographic inf.rmation systems （GIS） and to suggest an approach to predict other soil attributes. Soil depth was determined at 652 f.eld observations over the A1-Muwaqqar Watershed （70 km2） in Jordan. Terrain attributes derived f.om 30-m resolution DEMs were utilized to predict soil depth. The results indicated that the use of.multiple linear regression models within small watershed subdivisions enabled the prediction of.soil depth with a dif.erence of.50 cm f.r 77% of.the f.eld observations. The spatial distribution of.the predicted soil depth was visually coincided and had good correlations with the spatial distribution of.the classes amalgamating three terrain attributes, slope steepness, slope shape, and compound topographic index. These suggested that the modeling of.soil-landscape relationships within small watershed subdivisions using the three terrain attributes was a promising approach to predict other soil attributes.

关键词： compound topographic index digital elevation model GIS watershed

Modelling of.Gettering by Mechanical Damage of.Metallic Impurities in Silicon

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Chinese Physics Letters 2006年第11期23卷 3058-3060页

作者： f. Ayad M. Remram Department of.Electronics University of Mentourl Route of Ain El-Bay Constantine 25000 Algeria

Reducing the concentration of.the metallic impurities present in silicon-based electronic components plays a vital role in manuf.ctures. Gettering by induced mechanical damage is one of.the methods used in neutralizing these impurities. To simulate this type of.gettering, we explicitly include the role of.the traps due to mechanical damage, based on the mechanism of.kick-out. In our model, we choose the essential parameters including concentration of.impurities, thickness, temperature, time, etc. The dif.usion coef.icient and equilibrium concentration of.the silicon interstitials estimated f.om the literature have been adjusted to be in good agreement with the experimental data.

关键词： DIf.USION GOLD

Seasonal variations of.PM10 -- Trace elements, PAHs and Levoglucosan: Rural sugarcane growing area versus coastal urban area in Southeastern f.orida, USA. Part II: Elemental concentrations

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Particuology 2019年第5期17卷 99-108页

作者： Orhan Sevim oglu Wolf.ang f. Rogge Department of.Environmental Engineering Cebze Technical University Cebze Kocaeli 41400 Turkey School of.Engineering and Sierra Nevada Research Institute University of California Merced. 5200 North Lake Road Merced CA 95343 USA

The largest sugarcane-growing area in the United States is in South f.orida. An estimated 7 million tons of.dry sugarcane leaf. biomass is removed f.om the f.elds bef.re harvest by burning the leaves of. the sugarcane stalks. Preharvest sugarcane leaf.f.liage burning is a major source of.airborne particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs), biogenic trace elements such as K, volatile hydrocarbons and other pollutants. In one harvesting period, approximately 22 million tons of.C02, a greenhouse gas, is released, 7 million tons f.om leaf.f.liage preharvest burning alone and 15 million tons f.om burning sugarcane bagasse in the sugar mills f.r power generation. In this study, PMio was collected f.om Belle Glade, close to the sugarcane-growing area, and f.om Delray Beach, an urbanized area along the East Coast of.f.orida. The PM samples were analyzed f.r trace elements and close to organic compounds. To elucidate the importance of.preharvest sugarcane biomass smoke emissions on air quality, 39 trace elements, 18 PAHs, and levoglucosan were selected to apportion ambient PM constituents. Al, Ca and to a great extend also Mg are the major soil-related trace elements and key markers f.r f.gitive soil dust emissions. Similarly, sea salt aerosol blown f.om the Atlantic Ocean into f.orida added appreciably to PMio trace elements concentration, especially Na and Cl. Approximately half.of.the sea salt aerosol (PMjo -portion) by mass is removed f.om the atmosphere during the transport of.ocean air f.om Delray Beach to Belle Glade. Ambient acid displacement reactions caused a substantial portion of.the Cl (30%) to be liberated f.om the sea salt aerosol to the atmosphere during transport as gaseous HC1. The PAH concentrations at Belle Glade were high when the biomass combustion markers levoglucosan and If.f.liage is burned of. just bef.re harvest, most of

关键词： Urban versus rural Trace elements Sugarcane burning Rare earth elements Sea salt aerosol Potassium Levoglucosan PAHs

Three-dimensional simulation of.long-wavelength f.ee-electron lasers with helical wiggler and ion-channel guiding

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Chinese Physics B 2013年第7期22卷 183-191页

作者： f. Jaf.ri Bahman B. Maraghechi Department of.Physics Amirkabir University of Technology

A three-dimensional simulation of.a steady-state amplif.er model of.a long-wavelength f.ee-electron laser （f.L） with realizable helical wiggler and ion-channel guiding is presented. The set of.coupled nonlinear dif.erential equations f.r electron orbits and f.elds of.TE 11 mode in a cylindrical waveguide are solved numerically by the Runge–Kutta algorithm with averages calculated by the Gaussian quadrature technique. Self.f.elds and space-charge ef.ects are neglected, and the electron beam is assumed to be cold and slippage is ignored. The parameters correspond to the Compton regime. Evolution of.the radiation power and growth rate along the wiggler is studied. Ion-channel density is chosen to obtain optimum ef.iciency. Simulations are pref.rmed f.r the f.L operating in the neighborhood of.35 GHz and 16.5 GHz f.r the electron beam energies of.250 keV and 400 keV, respectively. The result of.the saturated ef.iciency was f.und to be in good agreement with the simple estimation based on the phase-trapping model.

关键词： f.ee-electron laser helical wiggler ion-channel guiding

Approximate solutions of.Schrdinger equation f.r Eckart potential with centrif.gal term

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Chinese Physics B 2010年第9期19卷 155-160页

作者： f. Taskin G. Koak Department of.Physics Erciyes University

The approximate analytical solutions of.the Schrodinger equation f.r the Eckart potential are presented f.r the arbitrary angular momentum by using a new approximation of.the centrif.gal term. The energy eigenvalues and the corresponding wavef.nctions are obtained f.r dif.erent values of.screening parameter. The numerical examples are presented and the results are in good agreement with the values in the literature. Three special cases, i.e., s-wave, ξ= λ=1, and β=0, are investigated.

关键词： Schrodinger equation Eckart potential bound state

Predicting global landslide spatiotemporal distribution:Integrating landslide susceptibility zoning techniques and real-time satellite rainf.ll estimates

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International Journal of.Sediment Research 2008年第3期23卷 249-257页

作者： Robert f. ADLER Senior Research Scientist Code 613.1 Laboratory for Atmospheres NASA/Goddard Space Flight Center Greenbelt MD 20771 U. S. ADr.

Landslides triggered by rainf.ll can possibly be f.reseen in real time by jointly using rainf.ll intensity-duration thresholds and inf.rmation related to land surf.ce susceptibility. However, no system exists at either a national or a global scale to monitor or detect rainf.ll conditions that may trigger landslides due to the lack of.suf.icient ground-based observing network in many parts of.the world. Recent advances in satellite remote sensing technology and increasing availability of.high-resolution geospatial products around the globe have provided an unprecedented opportunity f.r such a study. In this paper, a f.amework f.r developing a preliminary real-time prediction system to identif. where rainf.ll-triggered landslides will occur is proposed by combining two necessary components: surf.ce landslide susceptibility and a real-time space-based rainf.ll analysis system (http://***). f.rst, a global landslide susceptibility map is derived f.om a combination of.semi-static global surf.ce characteristics (digital elevation topography, slope, soil types, soil texture, land cover classif.cation, etc.) using a GIS weighted linear combination approach. Second, an adjusted empirical relationship between rainf.ll intensity-duration and landslide occurrence is used to assess landslide hazards at areas with high susceptibility. A major outcome of.this work is the availability f.r the f.rst time of.a global assessment of.landslide hazards, which is only possible because of.the utilization of.global satellite remote sensing products. This preliminary system can be updated continuously using the new satellite remote sensing products. This proposed system, if.pursued through wide interdisciplinary ef.orts as recommended herein, bears the promise to grow many local landslide hazard analyses into a global decision-making support system f.r landslide disaster preparedness and mitigation activities across the world.

关键词： Landslide Natural disasters Satellite remote sensing Real-time precipitation analysis Landslide susceptibility