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A Lumped particle Modeling Framework for Simulating particle Transport in Fluids

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Communications in Computational physics 2010年第6期8卷 115-142页

作者： Omar al-Khayat Are Magnus Bruaset hans petter Langtangen Computational Geosciences CBCSimula Research LaboratoryP.O.Box 134NO-1325 LysakerNorway Department of Informatics University of OsloP.O.Box 1080BlindernNO-0316 OsloNorway Center for Biomedical Computing Simula Research LaboratoryP.O.Box 134NO-1325 LysakerNorway

This paper presents a lumped particle model for simulating a large number of *** lumped particle model is a flexible framework in modeling particle flows,embodying fundamental features that are intrinsic in particle laden flow,including advection,diffusion and *** this paper,the particles obey a simplified version of the Bassinet-Boussinesq-Oseen equation for a single spherical ***,instead of tracking the individual dynamics of each particle,a weighted spatial averaging procedure is used where the external forces are applied to a“lump”of particles,from which an average position and velocity is *** temporal evolution of the particles is computed by partitioning the lumped particle into smaller entities,which are then transported throughout the physical *** smaller entities recombine into new particle lumps at their target *** particles prone to the effects of Brownian motion or similar phenomena,a symmetric spreading of the particles is included as *** experiments show that the lumped particle model reproduces the effects of Brownian diffusion and uniform particle transport by a fluid and *** late time scale diffusive nature of particle motion is also reproduced.

关键词： particle modeling framework particle transport lumped particle model

particle Collisions in a Lumped particle Model

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Communications in Computational physics 2011年第9期10卷 823-843页

This paper presents an extension of the lumped particle model in[1]to include the effects of particle *** lumped particle model is a flexible framework for the modeling of particle laden flows,that takes into account fundamental features,including advection,diffusion and dispersion of the *** this paper,we transform a binary collision model and concepts from kinetic theory into a collision procedure for the lumped particle *** apply this new collision procedure to investigate numerically the role of particle collisions in the hindered settling *** hindered settling effect is characterized by an increase in the effective drag coefficient CD that influences each particle in the *** coefficient is given by CD=(1−φ)−nC∗D,whereφis the volume fraction of particles,C∗D is the drag coefficient for a single particle,and n≃4.67 for creeping *** obtain an approximation for CD/C∗D by calculating the effective work done by collisions,and comparing that to the work done by the drag *** our numerical experiments,we observe a minimal value of n=***,by allowing high energy dissipation,an approximation for the classical value for creeping flow,n=4.7,is *** also obtain high values for n,up to n=6.5,which is consistent with recent physical experiments on the sedimentation of sand grains.

关键词： Lumped particle model particle collision hindered settling

Foraging ecology and diet of Bornean elephants(Elephas maximus borneensis)in the Sebuku forest area,North Kalimantan province of Indonesia:Do the choices matter?

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Integrative Zoology 2018年第2期13卷 219-223页

作者： Rachmat B.SUBA Nils G.p.BEVERIDGE Wawan KUSTIAWAN Geert R.DE SNOO hans H.DE IONGH Institute of Environmental Sciences University of LeidenLeidenthe Netherlands Faculty of Forestry Mulawarman UniversityCampus of Gunung KeluaSamarindaEast KalimantanIndonesia Department of Biology Evolutionary Ecology GroupUniversity of AntwerpBelgium

INTRODUCTION The Bornean elephant(Elephas maximus borneensis Deraniyagala,1950)is a genetically distinct subspecies of the Asian elephant(***)(Fernando et al.2003),possibly related to the Javan elephant,which became extinct following the disappearance of the Java-Borneo connection at the last glacial maximum(Cranbook et al.2008).*** has been listed as an endangered species(EN)on the IUCN Red List since 1986(IUCN 2016).

关键词： forest listed phant

Seasonal changes on two different spatial scales： response of aquatic invertebrates to water body and microhabitat

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Insect Science 2005年第4期12卷 263-280页

作者： WILCO C.E.p. VERBERK HEIN H. VAN KLEEF MARTIJN DIJKMAN pAUL VAN HOEK p.ter SpIERENBURG hans ESSELINK Bargerveen Foundation Radboud University Nijmegen Department of Environmental Studies Institute for Wetland and Water Research Radboud University Nijmegen Department of Animal Ecology and Ecophysiology Radboud University NijmegenNijmegen the Netherlands

Knowledge about the spatial and temporal scales of both habitat use and the functional significance of different adaptations is essential for an understanding of the population dynamics of invertebrate assemblages. This fundamental knowledge is not only interesting from an academic point of view, but is sorely lacking and needed in the field of restoration ecology. Many species are threatened due to degradation. Knowing what environmental conditions are needed dtLring the life cycle of these species is important in the design of restoration measures which aim to lift existing bottlenecks for threatened species. To assess the relative importance of water type and microhabitat in structuring the invertebrate assemblage during different seasons, invertebrates were sampled in three water bodies differing in trophic level and acidity. Different parts within a water body （microhabitats） were sampled separately and each water body was sampled in all four seasons. Results show that water body is an important factor structuring the invertebrate assemblage early in the season, whereas microhabitat became more important later in the season. Structural complexity of microhabitats was related to the type of locomotion employed by invertebrates. Seasonal differences could be related to population dynamics （reproduction, mortality）. Moreover, fluctuations in resource availability were expected to differ between the water bodies, with highest fluctuations in the eutrophic water body and with fluctuations becoming less predictable later in the season. This was confirmed by the data： species synchronization to pulses in food availability was strongest in the eutrophic water body. Moreover, synchronization was strongest in summer, while in autumn waters were invaded by dispersive species. Based on these results a synthesis is presented on the functioning of the different waters during the different seasons.

关键词： dispersal fluctuations in resource availability food substrate synchronization

A Revisit to the Swedish Wet Compaction Method—A Case Study of the Burvattnet Dam Reconstruction

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Open Journal of Civil Engineering 2023年第2期13卷 282-291页

作者： hans Rönnqvist Tina påhlstorp Daniel Gustavsson RQV Teknik AB Hudiksvall Sweden AFRY Malmö Sweden Vattenregleringsföretagen Östersund Sweden

The Swedish Wet compaction method allows soil compaction at higher water content than conventional Dry compaction methods and can be used to advantage when difficulties arise in keeping to a certain Dry compaction water content. Wet compaction was frequently applied for dam core soils of glacial till (moraine) up until late 1970s, and despite several advantages it is since no longer used in engineering practice. During the reconstruction of Burvattnet Main Dam in Sweden, the lack of dry core soil together with severe weather conditions made Dry compaction almost impossible. On the basis of laboratory compaction tests performed in compliance with the standard from the 1950s, and field compaction trials on site, this paper describes the steps taken to revisit the Wet compaction method, which made it possible to continue the filling works in keeping with the timeline of the project.

关键词： Soil Compaction Wet Compaction Laboratory Field Trial Glacial Till

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中国的骨碎补科(英文)

植物分类学报 1996年第2期34卷 162-179页

作者： hans p.Nooteboom 荷兰莱顿国家植物标本馆和植物园

本文讨论了骨碎补科属的划分问题,承认了骨碎补属、钻毛蕨属、雨蕨属和大膜盖蕨属。小膜盖蕨属和阴石蕨属的种类被并入到了骨碎补属。中国计有骨碎补科植物3属14种,其中骨碎补属12种,雨蕨属1种,大膜盖蕨属1种。

关键词：骨碎补科蕨类植物分类中国

Detecting the presence of natural forests using airborne laser scanning data

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Forest Ecosystems 2023年第6期10卷 668-680页

作者： Marie-Claude Jutras-perreault terje Gobakken Erik Næsset hans OleØrka Faculty of Environmental Sciences and Natural Resource Management Norwegian University of Life SciencesNMBUP.O.BoxNO-1432ÅsNorway

Centuries of forest exploitation have caused significant loss of natural forests in Europe,leading to a decline in populations for many *** prevent further loss in biodiversity,the Norwegian government has set a target of protecting 10%of the forested ***,recent data from the National Forest Inventory(NFI)reveals that less than 2%of Norway's forested area consists of natural *** identify forests with high conservation value,we used vertical and horizontal variables derived from airborne laser scanning(ALS)data,along with NFI plot *** study aimed to predict the presence of natural forests across three counties in southeastern Norway,using three different definitions:pristine,near-natural,and semi-natural *** forests are scarce,and their underrepresentation in field reference data can compromise the accuracy of the *** address this,we assessed the potential gain of including additional field data specifically targeting natural forests to achieve a better balance in the ***,we examined the impact of stratifying the data by dominant tree species on the performance of the *** results revealed that semi-natural forests were the most accurately predicted,followed by near-natural and pristine forests,with Matthews correlation coefficient values of 0.32,0.24,and 0.17,*** additional field data did not improve the ***,stratification by species improved the accuracy of predictions for near-natural and semi-natural forests,while reducing accuracy for pristine *** use of horizontal variables did not improve the *** study demonstrates the potential of ALS data in identifying forests with high conservation *** provides a basis for further research on the use of ALS data for the detection and conservation of natural forests,offering valuable insights to guide future forest preservation efforts.

关键词： Natural forest ALS Naturalness Vertical variables Horizontal variables Biodiversity Forest condition Ecosystem services

Effects of a novel bacterial phytase expressed in Aspergillus Oryzae on digestibility of calcium and phosphorus in diets fed to weanling or growing pigs

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Journal of Animal Science and Biotechnology 2013年第2期4卷 102-111页

作者： Ferdinando Nielsen Almeida Rommel Casilda Sulabo hans Henrik Stein Department of Animal Sciences University of Illinois

In 2 experiments, 48 weanling （initial BW： 13.5 ± 2.4 kg, Exp. 1） were used to determine effects of a novel bacterial 6-phytase and 24 growing pigs （initial BW： 36.2 ± 4.0 kg, Exp. 2） expressed in Aspergillus oryzae on the apparent total tract digestibility （ATTD） of phosphorus and calcium in corn-soybean meal diets fed to weanling and growing pigs. In Exp. 1 and 2, pigs were randomly allotted to 6 dietary treatments using a randomized complete block design and a balanced 2 period changeover design, respectively. In both experiments, 6 diets were formulated. The positive control diet was a corn-soybean meal diet with added inorganic phosphorus （Exp. 1：0.42 and 0.86% standardized total tract digestible phosphorus and total calcium, respectively; Exp. 2：0.32 and 0.79% standardized total tract digestible phosphorus and total calcium, respectively）. A negative control diet and 4 diets with the novel phytase （Ronozyme Hiphos, DSM Nutritional products Inc., parsippany, N J） added to the negative control diet at levels of 500, 1,000, 2,000, and 4,000 phytase units （FYT）/kg were also formulated. In Exp. 1, the ATTD of phosphorus was greater （p 〈 0.01） for the positive control diet （60.5%） than for the negative control diet （40.5%）, but increased （linear and quadratic, p 〈 0.01） as phytase was added to the negative control diet （40.5% vs. 61.6%, 65.1%, 68.7%, and 68.0%）. The breakpoint for the ATTD of phosphorus （68.4%） was reached at a phytase inclusion level of 1,016 FYT/kg. In Exp. 2, the ATTD of phosphorus was greater （p〈 0.01） for the positive control diet （59.4%） than for the negative control diet （39.8%） and increased （linear and quadratic, p〈 0.01） as phytase was added to the negative control diet （39.8% vs. 58.1%, 65.4%, 69.1%, and 72.8%）. The breakpoint for the ATTD of phosphorus （69.1%） was reached at a phytase inclusion level of 801 FYT/kg. in conclusion, the novel bacterial 6-phytase improved the ATTD of phosphorus and calcium in both weanling and growing pigs.

关键词： Calcium Digestibility phosphorus phytase pigs

EDISON-WMW: Exact Dynamic programing Solution of the Wilcoxon–Mann–Whitney Test

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Genomics, proteomics & Bioinformatics 2016年第1期14卷 55-61页

作者： Alexander Marx Christina Backes Eckart Meese hans-p.ter Lenhof Andreas Keller Chair for Clinical Bioinformatics Medical Faculty Saarland University Department of Human Genetics Saarland University University Hospital Chair for Bioinformatics Saarland University

In many research disciplines, hypothesis tests are applied to evaluate whether findings are statistically significant or could be explained by chance. The Wilcoxon-Mann-Whitney （WMW） test is among the most popular hypothesis tests in medicine and life science to analyze if two groups of samples are equally distributed. This nonparametric statistical homogeneity test is commonly applied in molecular diagnosis. Generally, the solution of the WMW test takes a high combinatorial effort for large sample cohorts containing a significant number of ties. Hence, p value is frequently approximated by a normal distribution. We developed EDISON-WMW, a new approach to calcu- late the exact permutation of the two-tailed unpaired WMW test without any corrections required and allowing for ties. The method relies on dynamic programing to solve the combinatorial problem of the WMW test efficiently. Beyond a straightforward implementation of the algorithm, we pre- sented different optimization strategies and developed a parallel solution. Using our program, the exact p value for large cohorts containing more than 1000 samples with ties can be calculated within minutes. We demonstrate the performance of this novel approach on randomly-generated data, benchmark it against 13 other commonly-applied approaches and moreover evaluate molec- ular biomarkers for lung carcinoma and chronic obstructive pulmonary disease （COpD）. We foundthat approximated p values were generally higher than the exact solution provided by EDISON- WMW. Importantly, the algorithm can also be applied to high-throughput omics datasets, where hundreds or thousands of features are included. To provide easy access to the multi-threaded version of EDISON-WMW, a web-based solution of our algorithm is freely available at http：// ***/software/wtest/.

关键词： Wilcoxon-Mann-Whitneytest:Wilcoxon rank-sum test Dynamic programing Exact permutation parallel optimization