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Viscoelasticity and shear resistance at the aggregate scale of structured and organic carbon-free Chernozems

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Pedosphere 2023年第5期33卷 754-764页

作者： Christoph HAAS Rainer HORN Philipp SAGGAU Rainer DUTTMANN Institute for Plant Nutrition and Soil Science University of KielKiel 24118Germany department of Geography Division of Landscape Ecology and Geoinformation SciencesUniversity of KielKiel 24118Germany

Soil rheology characterises the flow behaviour of soils at the particle-particle to aggregate *** sweep tests(ASTs)are often the method of choice for parameterizing soil flow properties,such as the shear strain values at the end of the linear viscoelastic range(i.e.,the deformation is mainly elastic)and at the yield point(i.e.,elastic equals plastic deformation).Samples from seven soil profiles and five soil depths of Chernozems,collected in the Maidanetske study area,close to Uman City of Ukraine,were analysed to evaluate the effect of soil organic carbon(SOC)on the parameters related to soil microstructural stability derived from *** organic carbon was removed with H_(2)O_(2)to determine the soil texture-dependent values of soil rheological properties,which were compared to the values determined for samples with intact water-stable *** shear resistance-related parameters increased for aggregated soil samples compared to SOC-free soil samples,indicating an increase in soil stability due to *** contrast,the values of the overall viscoelasticity and the shear strain were reduced for aggregated soil samples,indicating decreased soil *** functions were applied to predict the shear strain-dependent loss and storage moduli and shear stress values as a function of SOC *** particles(630–2000μm)and volumetric water content improved the *** conclude that increased SOC content,through the gluing and cementing effects of SOC and altered aggregate shapes compared to SOC-free soil materials,contributes to higher microstructural ***,the increased water content in the SOC-containing soil samples reversed soil strengthening *** was due to the fact that a more rapid increase in positive water pressure under shear stress weakened the samples and the spherical aggregates began to rotate more easily,thus loosing energy,when compared to platy particles of the SOC-free soil materials.

关键词： aggregation rheology shear strain shear stress soil organic carbon depletion soil stability

Authigenic gypsum found in gas hydrate-associated sediments from Hydrate Ridge, the eastern North Pacific

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Science China Earth Sciences 2004年第3期47卷 280-288页

作者： Erwin Suess Dirk Rickert department of Marine Environmental Geology Research Centre of Marine Geology University of Kiel Kiel D-24148 Germany Department of Marine Environmental Geology Research Centre of Marine Geology University of Kiel Kiel D-24148 Germany

Characteristic gypsum micro-sphere and granular mass were discovered by bin-ocular microscope in the gas hydrate-associated sediments at cores SO143-221 and SO143/TVG40-2A respectively on Hydrate Ridge of Cascadia margin, the eastern North Pacific. XRD patterns and EPA analyses show both micro-sphere and granular mass of the crystals have the typical peaks and the typical main chemical compositions of gypsum, although their weight percents are slightly less than the others in the non-gas hydrate-associated marine regions. SEM pictures show that the gypsum crystals have clear crystal boundaries, planes, edges and cleav-ages of gypsum in form either of single crystal or of twin crystals. In view of the fact that there are meanwhile gas hydrate-associated authigenic carbonates and SO42--rich pore water in the same sediment cores, it could be inferred reasonably that the gypsums formed also authigenically in the gas hydrate-associated environment too, most probably at the interface between the down-ward advecting sulfate-rich seawater and the below gas hydrate, which spilled calcium during its formation on Hydrate Ridge. The two distinct forms of crystal intergrowth, which are the granular mass of series single gypsum crystals at core SO143/TVG40-2A and the microsphere of gypsum crystals accompanied with detrital components at core SO143-221 respectively, indicate that they precipitated most likely in different interstitial water dynamic environments. So, the distinct authigenic gypsums found in gas hydrate-associated sediments on Hydrate Ridge could also be believed as one of the parameters which could be used to indicate the presence of gas hydrate in an unknown marine sediment cores.

关键词： authigenic gypsum, gas hydrate-associated sediment, Hydrate Ridge, eastern North Pacific.

Software development processes in ocean system modeling

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International Journal of Modeling, Simulation, and Scientific Computing 2022年第2期13卷 47-69页

作者： Reiner Jung Sven Gundlach Wilhelm Hasselbring Software Engineering Group Department of Computer Science Kiel UniversityKielGermany

Scientific modeling provides mathematical abstractions of real-world systems and builds software as implementations of these mathematical *** science is a multidisciplinary discipline developing scientific models and simulations as ocean sys-tem models that are an essential research *** software engineering and information systems research,modeling is also an essential *** particular,business process modeling for business process management and systems engineering is the activity of representing processes of an enterprise,so that the current process may be analyzed,improved and *** this paper,we employ process modeling for analyzing sci-entific software development in ocean science to advance the state in engineering of ocean system models and to better understand how ocean system models are developed and maintained in ocean *** interviewed domain experts in semi-structured inter-views,analyzed the results via thematic analysis,and modeled the results via the Busi-ness Process Modeling Notation(BPMN).The processes modeled as a result describe an aspired state of software development in the domain,which are often not(yet)*** enables existing processes in simulation-based system engineering to be improved with the help of these process models.

关键词： Scientific modeling software development processes process modeling the-matic analysis

Sustainable land management practices, off-farm work participation and vulnerability among farmers in Ghana: Is there a nexus?

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International Soil and Water Conservation Research 2019年第1期7卷 18-26页

作者： Gazali Issahaku Awal Abdul-Rahaman department of Food Economics and Consumption Studies University of KielJohanna-Mestorf-Str.524118 KielGermany

Addressing issues of agricultural sustainability and vulnerability to poverty under climate change are major challenges to development in the 21st *** for the trade-off and synergies between off-farm work participation and sustainable land management on one hand,and vulnerability to poverty on the other hand,will therefore be useful to *** this study,we use recent farm household data from Ghana to examine the effect of off-farm work participation on intensity of adoption of sustainable land management (SLM) practices and impact of off-farm work participation on vulnerability to *** employed a bivariate Tobit model to examine the determinants of SLM adoption intensity,and endogenous switching probit model to assess the impact of off-farm work participation on vulnerability to *** results reveal that participation in off-farm is positively and significantly associated with adoption intensity of bunds,and organic *** results also show that off-farm work participation significantly reduces household vulnerability to poverty by 13%.Based on these findings,we conclude that rural development through non-farm work opportunities can lead to positive synergies between sustainable agricultural production,off-farm employment and poverty alleviation.

关键词： Sustainable land management Adoption intensity Vulnerability Bivariate Tobit Endogenous switching probit

Comparison of cardioprotective effects of mibefradil and ramipril in stroke-prone spontaneously hypertensive rats

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Acta Pharmacologica Sinica 2004年第6期 61-66页

作者： Alexander REINECKE,Marc DORENKAMP,Christain STORZ,Havvo BITTERLING,Susanne PENZ,Jack CLEUTJENS,Mat JAP DAEMEN,Reichiger SIMON,Thomas UNGER Institute of Pharmacology University of kiel 24105 kiel Germany Institute of Pharmacology University of kiel 24105 kiel Germany Clinic of Cardiology Institute of Pharmacology University of kiel 24105 kiel Germany Institute of Pharmacology University of kiel 24105 kiel Germany University of kiel department of Pathology University ofMaastricht Maastricht The Netherlands Clinic of Cardiology University of kiel 24105 kiel Germany 24105 kiel Institute of Pharmacology University of kiel 24105 kiel Germany Germany Institute of Pharmacology University of kiel 24105 kiel Germany

AIM: To elucidate the cardioprotective effects of T-type calcium channel blocker mibefradil and compare with that of the angiotensin-converting enzyme inhibitor ramipril in a stroke-prone spontaneously hypertensive rats (SHR- SP) model of congestive heart failure (CHF) after myocardial infarction (MI). METHODS: SHR-SP rats were subjected to permanent ligation of the left anterior decending coronary artery. Treatment with mibefradil (10 mg·kg-1·d-1), ramipril (10 mg·kg-1·d-1), or placebo was initiated 4 weeks before surgery and continued up to 6 weeks after induction of MI. Sham-operated rats served as controls. RESULTS: In placebo-treated MI rats, six weeks after MI, left ventricular circumference, inner diameter, and left ventricular end-diastolic pressure (LVEDP) were increased, whereas mean arterial blood pressure (MAP) and maximum rate of rise of left ventricular pressure (dp/ dtmax) were decreased compared with sham-operated controls (P05), and dp/dtmax was improved (P<0.01) compared with placebo-treated MI rats. In contrast, in mibefradil-treated MI rats, heart weight, heart weight to body weight ratio were slightly but not signifi- cantly reduced, LVEDP was slightly elevated compared with placebo-treated MI rats, and was elevated (P<0.05) compared with ramipril-treated MI rats, although interstitial collagen content were reduced (P<0.01) compared with placebo-treated MI ***: Chronic treatment with ramipril diminishes cardiac remodeling of heart failure after MI to a greater extent than mibefradil. Moreover, 6 weeks after MI, mibefradil treatment results in a slight rise in LVEDP compared with placebo-treated rats. Therefore, treatment with mibefradil might be deleterious rather than beneficial compared with ramipril or even placebo treatment in experim

关键词： mibefradil ramipril angiotensin-converting enzyme inhibitors calcium channel blockers myocar- dial infarction heart failure cardiac remodeling ventricular function SHR-SP rats

Remediation of Trichloroethylene and Monochlorobenzene-Contaminated Aquifers Using the ORC-GAC-Fe^0-CaCO_3 System: Volatilization, Precipitation, and Porosity Losses

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Pedosphere 2007年第1期17卷 109-116页

作者： LIN Qi V. PLAGENTZ D. SCHAFER A. DAHMKE department ol Environmental Enginvering Zhejiang University Hangzhou 310029 （China） Institute of Geoscience Kiel Univevsity Olshausenstmsse 40 D-24098 Kiel （Germany）

The objectives of this study were to illustrate the reaction processes, to identify and quantify the precipitates formed, and to estimate the porosity losses in order to eliminate drawbacks during remediating monochlorobenzene （MCB） and trichloroethylene （TCE）-contaminated aquifers using the ORC-GAC-Fe^0-CaCO3 system. The system consisted of four columns （112 cm long and 10 cm in diameter） with oxygen-releasing compound （ORC）, granular activated carbon （GAC）, zero-valent iron （Fe^0）, and calcite used sequentially as the reactive media. The concentrations of MCB in the GAC column effluent and TCE in the Fe^0 column effluent were below the detection limit. However, the concentrations of MCB and TCE in the final calcite column exceeded the maximum contaminant level （MCL） under the Safe Drinking Water Act of the US Environmental Protection Agency （US EPA） that protects human health and environment. These results suggested that partitioning of MCB and TCE into the gas phase could occur, and also that transportation of volatile organic pollutants in the gas phase was important. Three main precipitates formed in the ORC-GAC-Fe^0-CaCO3 system： CaCO3 in the ORC column along with Fe（OH）2 and FeCO3 in the Fe^0 column. The total porosity losses caused by mineral precipitation corresponded to about 0.24% porosity in the ORC column, and 1% in the Fe^0 column. The most important cause of porosity losses was anaerobic corrosion of iron. The porosity losses caused by gas because of the production and entrapment of oxygen in the ORC column and hydrogen in the Fe^0 column should not be ignored. Volatilization, precipitation and porosity losses were considered to be the main drawbacks of the ORC-GAC-Fe^0-CaCO3 system in remediating the MCB and TCE-contaminated aquifers. Thus, measurements such as using a suitable oxygen-releasing compound, weakening the increase in pH using a buffer material such as soil, stimulating biodegradation rates and minimizing the plugging caused by the relati

关键词： groundwater remediation monochlorobenzene ORC-GAC-Fe^0-CaCO3 system trichloroethylene

Heat tolerance may determine activity time in coprophagic beetle species (Coleoptera:Scarabaeidae)

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Insect Science 2021年第4期28卷 1076-1086页

作者： Nonofo Gotcha Honest Machekano Ross N.Cuthbert Casper Nyamukondiwa department of Biological Sciences and Biotechnology Botswana International University of Science and TechnologyPalapyeBotswana GEOMAR Helmholtz-Zentrum fur Ozeanforschung KielKielGermany

Although reports have documented loss of species diversity and ecological services caused by stressful temperature changes that result from climate change,some species cope through behavioral *** temperatures and magnitudes of temperature extremes increase,animals should compensate to maintain fitness(such as through temporary behavioral shifts in activity times).Appropriate timing of activity helps avoid competition across *** coprophagic dung beetles exhibit species-specific temporal activity times,it is unknown whether temperature drives evolution of these species-specific temporal activity *** nine dung beetle species(three each of diurnal,crepuscular,and nocturnal species),we explored differences in heat stress tolerance measured as critical thermal maxima(CTmax;the highest temperature allowing activity)and heat knockdown time(HKDT;survival time under acute heat stress)across these species,and examined the results using a phylogenetically informed *** results showed that day-active species had significantly higher CTmax(diurnal>crepuscular=nocturnal species),whereas crepuscular species had higher HKDT(crepuscular>nocturnal>diurnal species).There was no correlation between heat tolerance and body size across species with distinct temporal activity,and no significant phylogenetic constraint for *** with higher CTmax did not necessarily have higher HKDT,which indicates that species may respond differently to diverse heat tolerance *** heat tolerance for diurnal beetles indicates that this trait may constrain activity time and,under high acute temperatures with climate change,species may shift activity times in more benign *** results contribute to elucidate the evolution of foraging behavior and management of coprophagic beetle ecosystem services under changing environments.

关键词： biodiversity climate change dung beetle ecosystem services thermal tolerance

Researches on the Internal Molecular Weight Uniformity of Chitosan Biomaterials

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Journal of Ocean University of China 2020年第2期19卷 459-465页

作者： LANG Xuqian LI Yang SUN Guohui ZHOU Zhongzheng LI Jing FENG Chao KONG Ming LIU Ya CHENG Xiaojie CHEN Xiguang College of Marine Life Science Ocean University of ChinaQingdao 266100China Zoological Institute Department of Molecular PhysiologyKiel UniversityKiel 24118Germany

Uniform molecular weight(Mw)chitosan(CS)is highly demanded in medical biomaterial *** present article described heterogeneous degradation of CS in aqueous HCl/ethanol solution,in which progress uniform Mw CS was successfully *** Mw distribution of CS was measured by gel permeation chromatography(GPC)***,the structure and properties of degraded CS were characterized by Fourier transform infrared spectroscopy(FT-IR),nuclear magnetic resonance spectroscopy(^1H NMR),X-ray diffraction(XRD)and thermogravimetric(TG)*** addition,the biocompatibility of degraded CS was also assessed by hemolysis rate(HR)*** Mw of CS dramatically decreased from 246 KDa to 76 k Da at the initial 30 min,and stabilized at 18 kDa after 24 *** analysis results showed that the degraded CS molecular become ***-IR and 1 H NMR analysis confirmed the basic structure of CS molecular backbone was not destroyed during this ***,the water solubility of CS was not significantly influenced by this ***,the XRD analysis revealed that crystallinity of degraded CS increased from 70.32% to 99.25%with *** TG analysis showed improved thermal stability of degraded *** measurement demonstrated the degraded CS possessed excellent *** simple and efficient heterogeneous degradation would open up a new route to produce uniform Mw CS.

关键词： chitosan heterogeneous degradation uniform molecular weight medical biomaterial

Glycolytic Shunts Replenish the Calvin-Benson-Bassham Cycle as Anaplerotic Reactions in Cyanobacteria

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Molecular Plant 2020年第3期13卷 471-482页

作者： Alexander Makowka Lars Nichelmann Dennis Schulze Katharina Spengler Christoph Wittmann Karl Forchhammer Kirstin Gutekunst department of Biology Botanical InstituteUniversity Kiel24118 KielGermany Institute for Systems Biotechnology Saarland University66123 SaarbruckenGermany Organismic Interactions department Interfaculty Institute for Microbiology and Infection MedicineUniversity

The recent discovery of the Entner-Doudoroff(ED)pathway as a third glycolytic route beside Embden-Meyerhof-Parnas(EMP)and oxidative pentose phosphate(OPP)pathway in oxygenic photoautotrophs requires a revision of their central carbohydrate *** this study,unexpectedly,we observed that deletion of the ED pathway alone,and even more pronounced in combination with other glycolytic routes,diminished photoautotrophic growth in continuous light in the cyanobacterium Synechocystis *** ***,we found that the ED pathway is required for optimal glycogen catabolism in parallel to an operating Calvin-Benson-Bassham(CBB)*** is counter-intuitive that glycolytic routes,which are a reverse to the CBB cycle and do not provide any additional biosynthetic intermediates,are important under photoautotrophic ***,observations on the ability to reactivate an arrested CBB cycle revealed that they form glycolytic shunts that tap the cellular carbohydrate reservoir to replenish the *** together,our results suggest that the classical view of the CBB cycle as an autocatalytic,completely autonomous cycle that exclusively relies on its own enzymes and C02 fixation to regenerate ribulose-1,5-bisphosphate for Rubisco is an *** propose that in common with other known autocatalytic cycles,the CBB cycle likewise relies on anaplerotic reactions to compensate for the depletion of intermediates,particularly in transition states and under fluctuating light conditions that are common in nature.

关键词： central carbohydrate metabolism Calvin-Benson-Bassham cycle Entner-Doudoroff pathway oxidative pentose phosphate pathway Embden-Meyerhof-Parnas pathway cyanobacteria