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Selection and Impact of an Aerofoil leading Edge on Boundary layer Transition

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Journal of Transportation Technologies 2022年第4期12卷 778-803页

作者： Dinesh Bhatia Devinder Kumar Yadav Guangjun Yang Jian Wang henrik Hesse School of Aerospace Engineering University of Glasgow Glasgow Singapore School of Aerospace University of Nottingham Ningbo China Ningbo China School of Aeronautics Northwestern Polytechnical University Xi’an China Faculty of Science Engineering and Computing Kingston University London UK

The choice of leading-edge aspect ratio (AR) plays a crucial role when planning boundary layer wind tunnel tests on a flat plate. Poor selection of the leading-edge profile hampers effectiveness of the experiment and increases testing costs associated with interchanging of leading edges to attain accurate results. Thus, the appropriate selection of the leading edge is a very crucial part of the wind tunnel experiment process. It is argued that the curvature of the leading edge and thus the AR is of paramount importance to achieve accurate results from the wind tunnel testing. In this project, seven different elliptical leading edges were tested, and their performance was compared with an ideal leading edge with zero thickness. Experiments and computation have been done for leading edges ranging from AR6 to AR20. Results were evaluated for boundary layer transition onset location, and it was found that AR20 has the least influence on the flow structure when compared to the ideal leading edge. A study of the flow structure at the stagnation point indicates an increase in adverse pressure gradient with an increase in the AR but also shows a decrease in the size of the stagnation region. The presence of a higher AR leading edge reduces the turbulent spot production rate, which is one of the primary causes of boundary layer transition. This paper presents a correlation that enables aerodynamicists to quantify the impact of the leading-edge AR on transition. A typical case is also presented to compare the relative performance of a wedge and the higher AR leading edge, which provides a choice between an elliptical or a wedge-shaped leading edge.

关键词： Boundary layer Transition leading Edge Aspect Ratio Curvature Flow Structure Adverse Pressure Gradient

Diversity patterns, environmental drivers and changes in vegetation composition in dry inter-Andean valleys

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Journal of Plant Ecology 2017年第3期10卷 461-475页

作者： Catalina Quintana Marco Girardello Anders S.Barfod henrik Balslev Department of Bioscience Ecoinformatics and Biodiversity GroupAarhus UniversityNy Munkegade 114DK-8000 Aarhus CDenmark Departamento de Ciencias Biológicas Pontificia Universidad Católica del EcuadorAv.12 de Octubre 1076Apartado postal 17012184QuitoEcuador

Aims We studied diversity,patterns of endemism and turnover of veg-etation composition in dry inter-Andean valleys(DIAVs)where lit-tle is known about the influence of the abiotic drivers controlling plant species composition and occurrences,and the life forms that contribute most toα-andβ-diversity,*** study was focused on DIAVs located in the highlands(800-2800 m)around the Equator(1°N-5°S).The following questions were addressed:(i)what differences exist between endemic and non-endemic species in terms of species number,frequency and abundance?(ii)are pat-terns ofα-andβ-diversity correlated with latitude?(iii)what are the major environmental drivers controlling spatial patterns in species composition and occurrence?Methods We established 63 transects of 5×100 m in areas with DIAV vegetation,impacted as little as possible by human *** each transect,all mature trees and shrubs were identified and counted to determine their *** coverage of terrestrial herbs was *** additive models were used to quantify the relationship betweenα-andβ-diversity with *** recordα-diversity,we used the exponential Shannon *** Sørensen index was used to measureβ-diversity or species *** used canonical correspondence analysis to deter-mine species composition and generalized linear mixed models to quantify simultaneously the determinants of species occur-rence across species and *** models were evaluated using the Akaike information *** analyses were run separately for trees,herbs and *** Findings Overall,we found that shrubs was the most diverse life form,constituting 43%(12%endemic)of the 313 species,followed by herbs(36%;11.5%endemic)and trees(20%;5%endemic).Trees comprise mostly species with low abundance(e.g.ls ha^(−1)),which was also true for herbs,whereas shrubs showed a larger number of abundant species(>30 individuals ha^(−1)),includ-ing four endemic *** of the e

关键词： endemics α-diversity β-diversity life forms Ecuador

Transactive control:a framework for operating power systems characterized by high penetration of distributed energy resources

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Journal of Modern Power Systems and Clean Energy 2017年第3期5卷 451-464页

作者： Junjie HU Guangya YANG Koen KOK Yusheng XUE henrik W.BINDNER Center for Electric Power and Energy Technical University of DenmarkCopenhagenDenmark Netherlands Organization for Applied Research TNOThe HagueThe Netherlands State Grid Electric Power Research Institute NanjingChina

The increasing number of distributed energy resources connected to power systems raises operational challenges for the network operator, such as introducing grid congestion and voltage deviations in the distribution network level, as well as increasing balancing needs at the whole system level. Control and coordination of a large number of distributed energy assets requires innovative approaches. Transactive control has received much attention due to its decentralized decision-making and transparent characteristics. This paper introduces the concept and main features of transactive control, followed by a literature review and demonstration projects that apply to transactive control. Cases are then presented to illustrate the transactive control framework. At the end, discussions and research directions are presented, for applying transactive control to operating power systems, characterized by a high penetration of distributed energy resources.

关键词： Distributed energy resources Distribution system operation Smart grids Transactive control

Morphology of living cells cultured on nanowire arrays with varying nanowire densities and diameters

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Science China(life Sciences) 2018年第4期61卷 427-435页

作者： Zhen li henrik Persson Karl Adolfsson Stina Oredsson Christelle N. Prinz Division of Solid State Physics Lund University Lund 22100 Sweden Nano lund Lund University Lund 22100 Sweden Department of Biology Lund 22362 Sweden Present address: Translational & Bioengineering Program Mechanical and Industrial Engineering University of Toronto Toronto MSG 1M1 ON Canada

Vertical nanowire arrays are increasingly investigated for their applications in steering cell behavior. The geometry of the array is an important parameter, which influences the morphology and adhesion of cells. Here, we investigate the effects of array geometry on the morphology of MCF7 cancer cells and MCF10 A normal-like epithelial cells. Different gallium phosphide nanowire array-geometries were produced by varying the nanowire density and diameter. Our results show that the cell size is smaller on nanowires compared to flat gallium phosphide. The cell area decreases with increasing the nanowire density on the substrate. We observed an effect of the nanowire diameter on MCF10 A cells, with a decreased cell area on 40 nm diameter nanowires, compared to 60 and 80 nm diameter nanowires in high-density arrays. The focal adhesion morphology depends on the extent to which cells are contacting the substrate. For low nanowire densities and diameters, cells are lying on the substrate and we observed large focal adhesions at the cell edges. In contrast, for high nanowire densities and diameters, cells are lying on top of the nanowires and we observed point-like focal adhesions distributed over the whole cell. Our results constitute a step towards the ability to fine-tune cell behavior on nanowire arrays.

关键词：高密度形态学房间直径数组生活教养几何学

low-level retention forestry, certification, and biodiversity: case Finland

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Ecological Processes 2019年第1期8卷 580-592页

作者： Timo Kuuluvainen henrik lindberg Ilkka Vanha-Majamaa Petri Keto-Tokoi Pekka Punttila Department of Forest Sciences University of HelsinkiP.O.Box 27FI-00014 HelsinkiFinland Häme University of Applied Sciences P.O Box 230FI-13100 HämeenlinnaFinland Natural Resources Institute Finland(luke) Latokartanonkaari 9FI-00790 HelsinkiFinland Tampere University of Applied Sciences PO Box 21FI-33521 TampereFinland Finnish Environment Institute Latokartanonkaari 11FI-00790 HelsinkiFinland

In managed forests,leaving retention trees during final harvesting has globally become a common approach to reconciling the often conflicting goals of timber production and safeguarding biodiversity and delivery of several ecosystem *** Finland,the dominant certification scheme requires leaving low levels of retention that can benefit some specific ***,species responses are dependent on the level of retention and the current low amounts of retention clearly do not provide the habitat quality and continuity needed for declining and redlisted forest species which are dependent on old living trees and coarse woody *** factors contribute to this ***,the ecological benefits of the current low retention levels are further diminished by monotonous standwise use of retention,resulting in low variability of retention habitat at the landscape ***,the prevailing timber-oriented management thinking may regard retention trees as an external cost to be minimized,rather than as part of an integrated approach to managing the ecosystem for specific ***,the main obstacles of development may still be institutional and *** development of retention practices in Finland indicates that the aim has not been to use ecological understanding to attain specific ecological sustainability goals,but rather to define the lowest level of retention that still allows access to the *** conclude that prevailing retention practices in Finland currently lack ecological credibility in safeguarding biodiversity and they should urgently be developed based on current scientific knowledge to meet ecological sustainability goals.

关键词： Boreal forest Ecological sustainability legacy structure Forest dynamics Forest certification Forest structure PEFC certification

lower extremity amputations and long-term outcomes in diabetic foot ulcers:A systematic review

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World Journal of Diabetes 2020年第9期11卷 391-399页

作者： Ayeshmanthe Rathnayake Apoorva Saboo Usman H Malabu henrik Falhammar Department of Medicine Townsville University HospitalTownsville 4814QueenslandAustralia School of Medicine and Dentistry James Cook UniversityTownsville 4811QueenslandAustralia Department of Endocrinology Metabolism and DiabetesKarolinska University HospitalStockholm 17176Sweden Department of Molecular Medicine and Surgery Karolinska InstitutetStockholm 17176Sweden

BACKGROUNDDiabetes mellitus causes a large majority of non-traumatic major and minoramputations globally. Patients with diabetes are clinically complex with amultifactorial association between diabetic foot ulcers (DFU) and subsequentlower extremity amputations (lEA). Few studies show the long-term outcomeswithin the cohort of DFU-associated *** highlight the long-term outcomes of lEA as a result of ***/MEDlINE and Google Scholar were searched for key terms, “diabetes”,“foot ulcers”, “amputations” and “outcomes”. Outcomes such as mortality, reamputation,re-ulceration and functional impact were recorded. Peer-reviewedstudies with adult patients who had DFU, subsequent amputation and follow upof at least 1 year were included. Non-English language articles or studiesinvolving children were *** total of 22 publications with a total of 2334 patients were selected against theinclusion criteria for review. The weighted mean of re-amputation was 20.14%,29.63% and 45.72% at 1, 3 and 5 years respectively. The weighted mean of mortality at 1, 3 and 5 years were 13.62%, 30.25% and 50.55% respectively withsignificantly higher rates associated with major amputation, re-amputation andischemic *** lEA, level of the lEA and patient comorbidities were significant riskfactors contributing to re-ulceration, re-amputation, mortality and depreciatedfunctional status.

关键词： lower extremity amputations long-term outcomes Diabetic foot ulcers Quality of life Re-amputation Diabetes

Amino acid digestibility of heat damaged distillers dried grains with solubles fed to pigs

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Journal of Animal Science and Biotechnology 2014年第1期5卷 88-97页

作者： Ferdinando Nielsen Almeida John Kyaw Htoo John Thomson Hans henrik Stein Department of Animal Sciences University of Illinois1207 W Gregory DrUrbana IL 61801 USA Evonik Industries AG Rodenbacher Chaussee 4Hanau 63457 Germany Evonik Degussa Corporation 1701 Barrett LakesBlvd NW Kennesaw GA 30144 USA

The primary objective of this experiment was to determine the effects of heat treatment on the standardized ileal digestibility （SID） of amino acids （AA） in corn distillers dried grains with solubles （DDGS） fed to growing pigs. The second objective was to develop regression equations that may be used to predict the concentration of SID AA in corn DDGS. A source of corn DDGS was divided into 4 batches that were either not autoclaved or autoclaved at 130℃ for 10, 20, or 30 min. Four diets containing DDGS from each of the 4 batches were formulated with DDGS being the only source of AA and CP in the diets. A N-free diet also was formulated and used to determine the basal endogenous losses of CP and AA. Ten growing pigs （initial BW： 53.5 ＋ 3.9 kg） were surgically equipped with a T-cannula in the distal ileum and allotted to a replicated 5 x4 Youden square design with 5 diets and 4 periods in each square. The SID of CP decreased linearly （P〈 0.05） from 77.9% in non-autoclaved DDGS to 72.1, 66.1, and 68.5% in the DDGS samples that were autoclaved for 10, 20, or 30 min, respectively. The SID of lysine was quadratically reduced （P〈 0.05） from 66.8% in the non-autoclaved DDGS to 54.9, 55.3, and 51.9% in the DDGS autoclaved for 10, 20, or 30 min, respectively. The concentrations of SID Arginine, Histidine, leucine, lysine, Methionine, Phenylalanine, or Threonine may be best predicted by equations that include the concentration of acid detergent insoluble N in the model （r2 = 0.76, 0.68, 0.67, 0.84, 0.76, 0.73, or 0.54, respectively）. The concentrations of SID Isoleucine and Valine were predicted （r2 = 0.58 and 0.54, respectively） by the lysine：CP ratio, whereas the concentration of SID Tryptophan was predicted （r2 = 0.70） by the analyzed concentration of Tryptophan in DDGS. In conclusion, the SID of AA is decreased as a result of heat damage and the concentration of SID AA in heat-damaged DDGS may be predicted by regression equations developed in this experiment.

关键词： Amino acids Digestibility Distillers dried grains with solubles Heat damage

功能性电刺激在步态功能恢复中的技术进展（英文）

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仪器仪表学报 2017年第6期38卷 1319-1334页

作者：孟琳 Bernd Porr henrik Gollee 思克莱德大学生物医学工程系格拉斯哥大学生物医学工程系

回顾了近几十年功能性电刺激在步态恢复中的技术进展。功能性电刺激干预的目的是对运动障碍(例如中风、脊髓损伤、多发性硬化症及其他)的人群进行功能性地步态恢复与康复治疗。近几年由于微纳米电子科技的快速发展,此项技术已被广泛应... 详细信息

回顾了近几十年功能性电刺激在步态恢复中的技术进展。功能性电刺激干预的目的是对运动障碍(例如中风、脊髓损伤、多发性硬化症及其他)的人群进行功能性地步态恢复与康复治疗。近几年由于微纳米电子科技的快速发展,此项技术已被广泛应用到实际当中。综述涵盖了在学术界研究开发和目前市场上可用的神经假肢,并对这些系统进行了深入地分析与讨论。尤其强调了传感技术和控制策略在系统中的应用,展望了该研究领域的发展前景,并提出结合功能性电刺激与机械外骨骼作为一项新兴方法来解决目前基于功能性电刺激的神经假肢研究中的困难问题。

关键词：功能性电刺激神经假体步态恢复闭环控制混合型外骨骼

An Alkali Activated Binder for High Chemical Resistant Self-leveling Mortar

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Open Journal of Composite Materials 2016年第4期6卷 132-142页

作者： henrik l. Funke Sandra Gelbrich lothar Kroll Institute of lightweight Structures Technische Universitat Chemnitz Chemnitz Germany

This paper reports the development of an Alkali Activated Binder (AAB) with an emphasis on the performance and the durability of the AAB-matrix. For the development of the matrix, the reactive components granulated slag and coal fly ash were used, which were alkali activated with a mixture of sodium hydroxide (2 - 10 mol/l) and aqueous sodium silicate solution (SiO2/Na2O molar ratio: 2.1) at ambient temperature. A sodium hydroxide concentration of 5.5 mol/l revealed the best compromise between setting time and mechanical strengths of the AAB. With this sodium hydroxide concentration, the compressive and the 3-point bending tensile strength of the hardened AAB were 53.4 and 5.5 MPa respectively after 14 days. As a result of the investigation of the acid resistance, the AAB-matrix showed a very high acid resistance in comparison to ordinary Portland cement concrete. In addition, the AAB had a high frost resistance, which had been validated by the capillary suction, internal damage and freeze thaw test with a relative dynamic E-Modulus of 93% and a total amount of scaled material of 30 g/m2 after 28 freeze-thaw cycles (exposure class: XF3).

关键词： Alkali Activated Binder Geopolymer Durability Chemical Resistance