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A review of the effects of forest fire on soil properties

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Journal of Forestry research 2022年第5期33卷 1419-1441页

作者： Alex Amerh Agbeshie simon Abugre thomas Atta-Darkwa richard Awuah Department of Environmental Management University of Energy and Natural Resources(UENR)SunyaniGhana Department of Forest Science University of Energy and Natural Resources(UENR)SunyaniGhana Department of Mechanical and Manufacturing Engineering University of Energy and Natural Resources(UENR)SunyaniGhana

Forest fires are key ecosystem modifiers affecting the biological,chemical,and physical attributes of forest *** extent of soil disturbance by fire is largely dependent on fire intensity,duration and recurrence,fuel load,and soil *** impact on soil properties is intricate,yielding different results based on these *** paper reviews research investigating the effects of wildfire and prescribed fire on the biological and physico-chemical attributes of forest soils and provides a summary of current knowledge associated with the benefits and disadvantages of such ***-intensity fires with ash deposition on soil surfaces cause changes in soil chemistry,including increase in available nutrients and *** intensity fires are noted for the complete combustion of organic matter and result in severe negative impacts on forest *** intensity fires result in nutrient volatilization,the break down in soil aggregate stability,an increase soil bulk density,an increase in the hydrophobicity of soil particles leading to decreased water infiltration with increased erosion and destroy soil *** soil heating(> 120℃) from high-intensity forest fires is detrimental to the soil ecosystem,especially its physical and biological *** this regard,the use of prescribed burning as a management tool to reduce the fuel load is highly recommended due to its low intensity and limited soil ***,the use of prescribed fires to manage fuel loads is critically needed in the light of current global warming as it will help prevent increased wildfire *** review provides information on the impact of forest fires on soil properties,a key feature in the maintenance of healthy *** addition,the review should prompt comprehensive soil and forest management regimes to limit soil disturbance and restore fire-disturbed soil ecosystems.

关键词： Forest fires Low-severity fire Mineralization Soil available nutrients Soil organic matter Volatilization

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Non-invasive means of measuring hepatic fat content

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World Journal of Gastroenterology 2008年第22期14卷 3476-3483页

作者： Sanjeev r Mehta E Louise thomas Jimmy D Bell Desmond G Johnston simon D Taylor-robinson Division of Medicine Imperial College London St Mary's Campus Praed Street London W2 1NY United Kingdom Imaging Sciences Depart-ment Division of Clinical Sciences Imperial College London Hammersmith Campus Du Cane Road London W12 OHS United Kingdom

Hepatic steatosis affects 20% to 30% of the general adult population in the western world. Currently, the technique of choice for determining hepatic fat deposition and the stage of fibrosis is liver biopsy. However, it is an invasive procedure and its use is limited, particularly in children. It may also be subject to sampling error. Non-invasive techniques such as ultrasound, computerised tomography (CT), magnetic resonance imaging (MrI) and proton magnetic resonance spectroscopy (1H MrS) can detect hepatic steatosis, but currently cannot distinguish between simple steatosis and steatohepatitis, or stage the degree of fibrosis accurately. Ultrasound is widely used to detect hepatic steatosis, but its sensitivity is reduced in the morbidly obese and also in those with small amounts of fatty infiltration. It has been used to grade hepatic fat content, but this is subjective. CT can detect hepatic steatosis, but exposes subjects to ionising radiation, thus limiting its use in longitudinal studies and in children. recently, magnetic resonance (Mr) techniques using chemical shift imaging have provided a quantitative assessment of the degree of hepatic fatty infiltration, which correlates well with liver biopsy results in the same patients. Similarly, in vivo 1H MrS is a fast, safe, non-invasive method forthe quantification of intrahepatocellular lipid (IHCL) levels. Both techniques will be useful tools in future longitudinal clinical studies, either in examining the natural history of conditions causing hepatic steatosis (e.g. non-alcoholic fatty liver disease), or in testing new treatments for these conditions.

关键词： Adipose tissue Ectopic fat Hepatic fat Insulin resistance Ultrasound Computerised tomography Magnetic resonance imaging Magnetic resonance spectroscopy

Two Types of Liquid Phase Separation Induced by Soft Centrifugation in Aqueous Ethyl Acetate Using Ethanol as Cosolvent

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research 2023年第3期6卷 451-460页

作者： Helmut Cölfen rose rosenberg Dirk Haffke simon Stemplinger thomas Zemb Dominik Horinek Physical Chemistry Department of ChemistryUniversity of KonstanzUniversitätsstr.10D-78457 KonstanzGermany Institute for Separation Chemistry ICSM U Montpellier/CEA/CNrS/ENSCM MarcouleFrance Institute of Physical and Theoretical Chemistry University of RegensburgD-93040 RegensburgGermany

Water/ethyl acetate/ethanol is widely used as a“green”extractant *** show that 2 different types of phase separation can be induced upon centrifugation in this ternary system using ethanol as a cosolvent of water and ethyl acetate:centrifuge-induced criticality and centrifuge-induced *** expected composition profiles of samples after centrifugation can be represented by bent lines in a ternary phase diagram when gravitational energy is added to the free energy of *** experimental equilibrium composition profiles behave qualitatively as expected and can be predicted using a phenomenological theory of *** concentration gradients are small except near the critical point,as expected for small ***,they are usable when accompanied by temperature *** findings open new possibilities of centrifugal separation,even if control is delicate during temperature *** schemes are accessible even at relatively low centrifugation speed for molecules that float and sediment with apparent molar masses several hundred times larger than the molecular mass.

关键词： separation ternary apparent

International Eclogite Field Symposium and Workshop of the Task Force IV, International Lithosphere Program

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Episodes 2008年第3期31卷 351-352页

作者： Lapen, thomas Cuthbert, simon Dobrzhinetskaya, Larissa Univ Houston Dept Geosci ILP Houston TX 77204 USA Univ W Scotland Chair Inst Ecol Field Symposium Org Committee Sch Sci & Engn Paisley PA1 2BE Renfrew Scotland Univ Calif riverside ILP Dept Earth Sci Riverside CA 92521 USA

The 2007 International Eclogite Field Sym- posium held in Portree, Isle of Skye, Scotland from June 29th to July 6th was a joint meeting of the International Eclogite Confer- ence, International Lithosphere Program Task Force IV ＂Ultra-deep Continental Crust Subduction＂, and the Metamorphic Studies Group. The Symposium consisted of two days of conference sessions and inter-, pre- and post-conference field excursions. The thematic conference included two sessions,

关键词：榴辉岩岩石圈国际组织地理信息

Effects of endothelin ETA receptor blocker LU 135252 on cardiac remod-eling and survival in a hypertensive rat model of chronic heart failure

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Acta Pharmacologica Sinica 2006年第11期27卷 1417-1422页

作者： Alexander rEINECKE Marc DOrENKAMP Mat Jap DAEMEN reichiger.simon thomas UNGEr Clinic of Cardiology Christian-Albrechts-University of Kiel24105 KielGermany Institute of Pharmacology Christian-Albrechts University of Kiel24105 KielGermany Department of Pathology University of MaastrichtMaastrichtthe Netherlands

Aim:To investigate whether the endothelin ETAreceptor blocker provides similarbenefit on cardiac remodeling and survival in a hypertensive rat model of chronicheart failure（CHF）.Methods:Male stroke-prone spontaneously hypertensive（SHr-SP）rats were subjected to permanent ligation of the left coronary artery andwere treated for 6 weeks with the endothelin ETAreceptor blocker LU 135252(***-1.d-1)starting 24 h after ligation or ***-operated rats servedas normal *** mean arterial blood pressure（MAP）,heart rate（Hr）,leftventricular end-diastolic pressure（LVEDP）,left ventricular contractility(LVdp/dtmax),left ventricular inner diameter（LVD）and circumference（LVC）,septalthickness,left ventricular interstitial collagen content（ICC）and heart weight（HW）were measured at the end of the ***:Compared with the untreatedgroup,LU 135252 tended to increase HW（1.43±0.03 vs 1.38±0.04 g;P>0.05）,increased LVD（7.65±0.24 mm vs 6.58±0.14 mm;Prkedly increased LVC（30.11±0.83 mm vs 24.82±0.85 mm;Preduced left ventricular ICC（3.79%±0.09% vs 6.71%±0.11%;Pred MAP（132±6mmHg vs142±4 mmHg;P>0.05）,reduced LVEDP（144mmHg vs 27±4 mmHg;Proved LV dp/dtmax（4230±450 mmHg/s vs 1950±400 mmHg/s;Prvivalwas not prolonged significantly（13% vs 11%;P=NS）.Conclusion:In this hyper-tensive rat model of CHF,chronic endothelin ETA receptor blockade with LU 135252improves cardiac hemodynamics,however,it does not affect long-term survivaland worsens cardiac ***,endothelin ETAreceptor antagonists areunlikely to have an important role in the management of patients with CHF.

关键词： myocardial infarction heart failure endothelin ET_A receptor antagonism LU 135252 cardiac remodeling ventricular function SHr-SP rats

An evolutionary perspective on conflict and compensation in physiological and functional traits

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Current Zoology 2014年第6期60卷 755-767页

作者： Jerry F. HUSAK simon r LAILVAUX Department of Biology University of St. Thomas 2115 Summit Avenue St Paul MN 55105 USA Department of Biological Sciences University of New Orleans 2000 Lakeshore Drive New Orleans LA 70148 USA

Physiological and functional traits, especially those related to behavior and whole-organism performance capacities, are subject to a variety of both parallel and opposing natural and sexual selection pressures. These selection pressures show considerable interspeciflc variation, shaping contemporary behavioral and functional diversity, but the form and intensity of selection on physiological and functional traits can also vary intraspecifically. The same suites of traits can experience quite different se- lection pressures, depending on the sex or age of a given individual, as well as the presence and nature of alternative reproductive strategies and tactics. These inter- and intra-locus genetic conflicts have potentially important consequences for the evolutionary trajectories of traits subject to them. Consequently, any intraspecific conflicts which could displace traits from their selective op- tima in certain classes of individuals relative to others are expected to result in selection for mechanisms to compensate for devia- tion from those optima. Such conflicts include interlocus sexual conflict, intralocus sexual conflict, and interacting phenotypes, as well as conflict within a sex. In this paper, we consider the evidence for, and implications of, such conflicts for physiological and functional traits in diverse taxa, including both vertebrates and invertebrates, and evaluate the various mechanisms, ranging from behavioral and mechanical to energetic and genetic, enabling compensation. We also discuss how pre- and post-mating conflicts, as well as interacting phenotypes, might affect the evolution of behavior and physiological and functional traits. Investigators that seek to understand the links among behavior, morphology, physiology, and function should consider such conflicts.

关键词： Sexual Conflict Compensation Sexual Selection Whole-organism Performance

Transient voltage stresses in MMC-HVDC links-impulse analysis and novel proposals for synthetic laboratory generation

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High Voltage 2018年第2期3卷 115-125页

作者： Claudius Freye simon Wenig Max Goertz thomas Leibfried Frank Jenau Institute of High Voltage Engineering TU Dortmund University44227 DortmundGermany Institute of Electrical Energy Systems and High-Voltage Technology Karlsruhe Institute of Technology(KIT)76131 KarlsruheGermany

To evaluate and optimise insulation coordination concepts for state of the art high-voltage direct current(HVDC)transmission systems,appropriate test voltage shapes are required for laboratory imitation of occurring *** especially transient voltages in the monopolar modular multilevel converter(MMC)-HVDC links show an extensive deviation from commonly applied switching impulse shapes,this study focusses on the analysis of over-voltages subsequent to direct current pole to ground ***,novel methods for synthetic laboratory test voltage generation are *** on simulated transients occurring during fault scenarios in different symmetrical monopolar±320 kV MMC-HVDC schemes,curve fitting,and related analysis techniques are used in order to compare simulated over-voltages with standard test voltage ***,these techniques further allow the identification of novel relevant impulse ***,design considerations for the generation of non-standard impulses based on single-stage circuits are derived and *** synthetically generated voltages may,later on,provide the basis for future investigations on related dielectric effects caused by those non-normative over-voltages.

关键词： analysis insulation transient

Insights into the radial water jet drilling technology-Application in a quarry

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Journal of rock Mechanics and Geotechnical Engineering 2018年第2期10卷 236-248页

作者： thomas reinsch Bob Paap simon Hahn Volker Wittig Sidney van den Berg GFZ German research Centre for Geosciences Telegrafenberg14473 PotsdamGermany TNO Sustainable Geo EnergyUtrechtThe Netherlands International Geothermal Centre-GZB Lennershofstr.14044801 BochumGermany Well Services Group Phileas Foggstraat 65NL-7825 AL EmmenThe Netherlands

In this context, we applied the radial water jet drilling(rJD) technology to drill five horizontal holes into a quarry wall of the Gildehaus quarry close to Bad Bntheim, Germany. For testing the state-of-the-art jetting technology, a jetting experiment was performed to investigate the influence of geological heterogeneity on the jetting performance and the hole geometry, the influence of nozzle geometry and jetting pressure on the rate of penetration, and the possibility of localising the jetting nozzle utilizing acoustic activity. It is observed that the jetted holes can intersect fractures under varying angles, and the jetted holes do not follow a straight path when jetting at ambient surface condition. Cuttings from the jetting process retrieved from the holes can be used to estimate the reservoir rock permeability. Within the quarry, we did not observe a change in the rate of penetration due to jetting pressure *** monitoring was partially successful in estimating the nozzle location. Although the experiments were performed at ambient surface conditions, the results can give recommendations for a downhole application in deep wells.

关键词： Acoustic monitoring Drilling performance Trajectory Permeability rock properties radial water jet drilling(rJD)

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A system-on-chip microwave photonic processor solves dynamic rF interference in real time with picosecond latency

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Light(Science & Applications) 2024年第1期13卷 91-102页

作者： Weipeng Zhang Joshua C.Lederman thomas Ferreira de Lima Jiawei Zhang simon Bilodeau Leila Hudson Alexander Tait Bhavin J.Shastri Paul r.Prucnal Department of Electrical and Computer Engineering Princeton UniversityPrinceton08544NJUSA NEC Laboratories America Princeton08540NJUSA Department of Electrical and Computer Engineering Queen’s UniversityKingstonK7L 3N6OntarioCanada Department of Physics Engineering Physics and AstronomyQueen’s UniversityKingstonK7L 3N6OntarioCanada

radio-frequency interference is a growing concern as wireless technology advances,with potentially life-threatening consequences like interference between radar altimeters and 5 G cellular *** transceivers mix signals with varying ratios over time,posing challenges for conventional digital signal processing(DSP)due to its high *** challenges will worsen as future wireless technologies adopt higher carrier frequencies and data ***,conventional DSPs,already on the brink of their clock frequency limit,are expected to offer only marginal speed *** paper introduces a photonic processor to address dynamic interference through blind source separation(BSS).Our system-on-chip processor employs a fully integrated photonic signal pathway in the analogue domain,enabling rapid demixing of received mixtures and recovering the signal-of-interest in under 15 *** reduction in latency surpasses electronic counterparts by more than three orders of *** complement the photonic processor,electronic peripherals based on field-programmable gate array(FPGA)assess the effectiveness of demixing and continuously update demixing weights at a rate of up to 305 *** compact setup features precise dithering weight control,impedance-controlled circuit board and optical fibre packaging,suitable for handheld and mobile *** experimentally demonstrate the processor’s ability to suppress transmission errors and maintain signal-to-noise ratios in two scenarios,radar altimeters and mobile *** work pioneers the real-time adaptability of integrated silicon photonics,enabling online learning and weight adjustments,and showcasing practical operational applications for photonic processing.

关键词： processor mixing dynamic