587 research outputs found
Natural gaits of the non-pathological flat foot and high-arched foot
There has been a controversy as to whether or not the non-pathological flat
foot and high-arched foot have an effect on human walking activities. The 3D
foot scanning system was employed to obtain static footprints from subjects
adopting a half-weight-bearing stance. Based upon their footprints, the
subjects were divided into two groups: the flat-footed and the high-arched. The
plantar pressure measurement system was used to measure and record the
subjects' successive natural gaits. Two indices were proposed: distribution of
vertical ground reaction force (VGRF) of plantar and the rate of the footprint
areas. Using these two indices to compare the natural gaits of the two subject
groups, we found that (1) in stance phase, there is a significant difference
(p<0.01) in the distributions of VGRF of plantar; (2) in a stride cycle, there
is also a significant difference (p<0.01) in the rates of the footprint areas.
Our analysis suggests that when walking, the VGRF of the plantar brings greater
muscle tension to the flat-footed while a smaller rate of the footprint areas
brings greater stability to the high-arched.Comment: 8 pages, 4 figure
Shedding light on the elusive role of endothelial cells in cytomegalovirus dissemination.
Cytomegalovirus (CMV) is frequently transmitted by solid organ transplantation and is associated with graft failure. By forming the boundary between circulation and organ parenchyma, endothelial cells (EC) are suited for bidirectional virus spread from and to the transplant. We applied Cre/loxP-mediated green-fluorescence-tagging of EC-derived murine CMV (MCMV) to quantify the role of infected EC in transplantation-associated CMV dissemination in the mouse model. Both EC- and non-EC-derived virus originating from infected Tie2-cre(+) heart and kidney transplants were readily transmitted to MCMV-naĂŻve recipients by primary viremia. In contrast, when a Tie2-cre(+) transplant was infected by primary viremia in an infected recipient, the recombined EC-derived virus poorly spread to recipient tissues. Similarly, in reverse direction, EC-derived virus from infected Tie2-cre(+) recipient tissues poorly spread to the transplant. These data contradict any privileged role of EC in CMV dissemination and challenge an indiscriminate applicability of the primary and secondary viremia concept of virus dissemination
Template Route to Chemically Engineering Cavities at Nanoscale: A Case Study of Zn(OH)2 Template
A size-controlled Zn(OH)2 template is used as a case study to explain the chemical strategy that can be executed to chemically engineering various nanoscale cavities. Zn(OH)2 octahedron with 8 vertices and 14 edges is fabricated via a low temperature solution route. The size can be tuned from 1 to 30 ÎŒm by changing the reaction conditions. Two methods can be selected for the hollow process without loss of the original shape of Zn(OH)2 template. Ion-replacement reaction is suitable for fabrication of hollow sulfides based on the solubility difference between Zn(OH)2 and products. Controlled chemical deposition is utilized to coat an oxide layer on the surface of Zn(OH)2 template. The abundant hydroxyl groups on Zn(OH)2 afford strong coordination ability with cations and help to the coating of a shell layer. The rudimental Zn(OH)2 core is eliminated with ammonia solution. In addition, ZnO-based heterostructures possessing better chemical or physical properties can also be prepared via this unique templating process. Room-temperature photoluminescence spectra of the heterostructures and hollow structures are also shown to study their optical properties
The Relationship Between Anthropometric Measures, Blood Gases, and Lung Function in Morbidly Obese White Subjects
# The Author(s) 2010. This article is published with open access at Springerlink.com Background Obesity may cause adverse effects on the respiratory system. The main purpose of this study was to investigate how various measures of obesity are related to arterial blood gases and pulmonary function. Methods This is a cross-sectional study of consecutive morbidly obese patients with normal lung function. Blood gas samples were taken from the radial artery after 5 min of rest with subjects sitting upright. Lung function measurements included dynamic spirometry, static lung volumes, and gas diffusing capacity. Results The 149 patients (77 % women) had a mean (SD) age of 43 years (11 years) and BMI of 45.0 kg/m 2 (6.3 kg/m 2). The mean expiratory reserve volume (ERV) was less than half (49%) of predicted value, whilst most other lung function values were within predicted range. Forty-two patients had an abnormally low pO2 value (<10.7 kPa [80 mmHg]), while eight patients had a high pCO2 value (>6.0 kPa [45 mmHg])
Undrained expansion of a cylindrical cavity in clays with fabric anisotropy: theoretical solution
This paper presents a novel, exact, semi-analytical solution for the quasi-static undrained expansion of a
cylindrical cavity in soft soils with fabric anisotropy. This is the first theoretical solution of the undrained expansion of a cylindrical cavity under plane strain conditions for soft soils with anisotropic behaviour of plastic nature. The solution is rigorously developed in detail, introducing a new stress invariant to deal with the soil fabric. The semianalytical solution requires numerical evaluation of a system of six first-order ordinary differential equations. The results agree with finite element analyses and show the influence of anisotropic plastic behaviour. The effective stresses at critical state are constant, and they may be analytically related to the undrained shear strength. The initial vertical cross-anisotropy caused by soil deposition changes towards a radial cross-anisotropy after cavity expansion. The analysis of the stress paths shows that proper modelling of anisotropic plastic behaviour involves modelling not only the initial fabric anisotropy but also its evolution with plastic straining.The research was initiated as part of GEO-INSTALL (Modelling Installation Effects in
Geotechnical Engineering, PIAP-GA-2009-230638) and CREEP (Creep of
Geomaterials, PIAP-GA-2011-286397) projects supported by the European Community
through the programme Marie Curie Industry-Academia Partnerships and Pathways
(IAPP) under the 7th Framework Programme
Shakedown Limits of Slab Track Substructures and Their Implications for Design
This paper presents an approach to shakedown of slab track substructures subjected to train loads. The train load is converted into a distributed moving load on the substructure surface using a simplified track analysis. Based on the lower-bound dynamic shakedown theorem, shakedown solutions for the slab track substructures are obtained over a range of train speeds between zero and the critical speed of the track. It is found the shakedown limit is largely influenced by the ratio of layer elastic moduli and the ratio of train speed to critical speed rather than their absolute values. An attenuation factor, as a function of the critical speed and the friction angle of subsoil, is proposed to effectively obtain the shakedown limit of the slab track substructure at any train speed. In light of the shakedown solutions, improvements to the existing design and analysis approaches are also suggested
Life cycle greenhouse gas emissions of blended cement concrete including carbonation and durability
The final publication is available at Springer via http://dx.doi.org/10.1007/s11367-013-0614-0Purpose Blended cements use waste products to replace
Portland cement, the main contributor to CO2 emissions in
concrete manufacture. Using blended cements reduces the
embodied greenhouse gas emissions; however, little attention
has been paid to the reduction in CO2 capture (carbonation)
and durability. The aim of this study is to determine if the
reduction in production emissions of blended cements compensates
for the reduced durability and CO2 capture.
Methods This study evaluates CO2 emissions and CO2 capture
for a reinforced concrete column during its service life
and after demolition and reuse as gravel filling material.
Concrete depletion, due to carbonation and the unavoidable
steel embedded corrosion, is studied, as this process consequently
ends the concrete service life. Carbonation deepens
progressively during service life and captures CO2 even after
demolition due to the greater exposed surface area. In this
study, results are presented as a function of cement replaced
by fly ash (FA) and blast furnace slag (BFS).
Results and discussion Concrete made with Portland cement,
FA (35%FA), and BFS blended cements (80%BFS) captures
47, 41, and 20 % of CO2 emissions, respectively. The service
life of blended cements with high amounts of cement replacement,
like CEM III/A (50 % BFS), CEM III/B (80 % BFS),
and CEMII/B-V (35%FA), was about 10%shorter, given the
higher carbonation rate coefficient. Compared to Portland
cement and despite the reduced CO2 capture and service life,
CEM III/B emitted 20 % less CO2 per year.
Conclusions To obtain reliable results in a life cycle assessment,
it is crucial to consider carbonation during use and
after demolition. Replacing Portland cement with FA, instead
of BFS, leads to a lower material emission factor, since
FA needs less processing after being collected, and transport
distances are usually shorter. However, greater reductions
were achieved using BFS, since a larger amount of cement
can be replaced. Blended cements emit less CO2 per year
during the life cycle of a structure, although a high cement
replacement reduces the service life notably. If the
demolished concrete is crushed and recycled as gravel filling
material, carbonation can cut CO2 emissions by half. A case
study is presented in this paper demonstrating how the results
may be utilized.This research was financially supported by the Spanish Ministry of Science and Innovation (research project BIA2011-23602). The authors thank the anonymous reviewers for their constructive comments and useful suggestions. The authors are also grateful for the thorough revision of the manuscript by Dr. Debra Westall.GarcĂa Segura, T.; Yepes Piqueras, V.; AlcalĂĄ GonzĂĄlez, J. (2014). Life cycle greenhouse gas emissions of blended cement concrete including carbonation and durability. International Journal of Life Cycle Assessment. 19(1):3-12. https://doi.org/10.1007/s11367-013-0614-0S312191AĂŻtcin PC (2000) Cements of yesterday and today: concrete of tomorrow. Cem Concr Res 30(9):1349â1359Angst U, Elsener B, Larsen C (2009) Critical chloride content in reinforced concreteâa review. Cement Concr Res 39(12):1122â1138Berge B (2000) The ecology of building materials. Architectural Press, OxfordBertolini L, Elsener B, Pedeferri P, Polder R (2004) Corrosion of Steel in ConcreteâPrevention Diagnosis. Repair, Wiley-VCH, WeinheimBörjesson P, Gustavsson L (2000) Greenhouse gas balances in building construction: wood versus concrete from life cycle and forest land-use perspectives. Energy Policy 28(9):575â588Camp CV, Huq F (2013) CO2 and cost optimization of reinforced concrete frames using a big bang-crunch algorithm. Eng Struct 48:363â372CEN (2011) EN 197â1: Cement. Part 1: Composition, specifications and conformity criteria for common cements. European Committee for Standardization, BrusselsCIWMB (2000) Designing with vision: a technical manual for materials choices in sustainable construction. California Integrated Waste Management Board, SacramentoCollins F (2010) Inclusion of carbonation during the life cycle of built and recycled concrete: influence on their carbon footprint. Int J Life Cycle Assess 15(6):549â556Database BEDEC (2012) Institute of Construction Technology of Catalonia. Barcelona, SpainDodoo A, Gustavsson L, Sathre R (2009) Carbon implications of end-of-life management of building materials. Resour Conserv Recy 53(5):276â286ECO-SERVE Network Cluster 3 (2004) Baseline Report for the Aggregate and Concrete Industries in Europe. European Commission, Hellerup: http://www.eco-serve.net/uploads/479998_baseline_report_final.pdf , accessed 10 September 2012European Federation of Concrete Admixtures Associations (2006) Environmental Product Declaration (EPD) for Normal Plasticizing admixtures. Environmental Consultant, Sittard: http://www.efca.info/downloads/324%20ETG%20Plasticiser%20EPD.pdf , accessed 13 October 2012GalĂĄn I (2011) CarbonataciĂłn del hormigĂłn: combinaciĂłn de CO2. Dissertation, Universidad Complutense de Madrid, SpainGalĂĄn I, Andrade C, Mora P, Sanjuan MA (2010) Sequestration of CO2 by concrete carbonation. Environ Sci Technol 44(8):3181â3186Flower DJM, Sanjayan JG (2007) Greenhouse gas emissions due to concrete manufacture. Int J Life Cycle Assess 12(5):282â288GuzmĂĄn S, GĂĄlvez JC, Sancho JM (2011) Cover cracking of reinforced concrete due to rebar corrosion induced by chloride penetration. Cement Concr Res 41(8):893â902Houst YF, Wittmann FH (2002) Depth profiles of carbonates formed during natural carbonation. C Cement Concr Res 32(12):1923â1930Institute for Diversification and Energy Saving (2010) Conversion factors of primary energy and CO2 emissions of 2010. M. Industria, EnergĂa y Turismo, Madrid, Spain: http://www.idae.es/index.php/mod.documentos/mem.descarga?file=/documentos_Factores_Conversion_Energia_y_CO2_2010_0a9cb734.pdf , accessed 10 September 2012ISO (2005) ISO/TC 71âBusiness plan. Concrete, reinforced concrete and prestressed concrete. International Organization for Standardization (ISO), Geneva, SwitzerlandISO (2006) ISO 14040: Environmental managementâlife-cycle assessmentâprinciples and framework. International Organization for Standardization, Geneva, SwitzerlandJiang L, Lin B, Cai Y (2000) A model for predicting carbonation of high-volume fly ash concrete. Cement Concr Res 30(5):699â702Jönsson A, Björklund T, Tillman AM (1988) LCA of concrete and steel building frames. Int J Life Cycle Assess 3(4):216â224Knoeri C, SanyĂ©-Mengual E, Althaus HJ (2013) Comparative LCA of recycled and conventional concrete for structural applications. Int J Life Cycle Assess 18(5):909â918Lagerblad B (2005) Carbon dioxide uptake during concrete life-cycle: State of the art. Swedish Cement and Concrete Research Institute, StockholmLeber I, Blakey FA (1956) Some effects of carbon dioxide on mortars and concrete. J Am Concr Inst 53:295â308Fomento M (2008) EHE-08; Code of Structural Concrete. M. Fomento, Madrid, SpainMarinkovic S, Radonjanin V, MaleĆĄev M, Ignjatovic I (2010) Comparative environmental assessment of natural and recycled aggregate concrete. Waste Manag 30(11):2255â2264Martinez-Martin FJ, Gonzalez-Vidosa F, Hospitaler A, Yepes V (2012) Multi-objective optimization design of bridge piers with hybrid heuristic algorithms. J Zhejiang Univ-SCI A 13(6):420â432OâBrien KR, MĂ©nachĂ© J, OâMoore LM (2009) Impact of fly ash content and fly ash transportation distance on embodied greenhouse gas emissions and water consumption in concrete. Int J Life-cycle Assess 14(7):621â629Pade C, Guimaraes M (2007) The CO2 uptake of concrete in a 100-year perspective. Cem Concr Res 37(9):1384â1356Papadakis VG, Vayenas CG, Fardis MN (1991) Fundamental modeling and experimental investigation of concrete carbonation. ACI Mater J 88(4):363â373PayĂĄ I, Yepes V, GonzĂĄlez-Vidosa F, Hospitaler A (2008) Multiobjective optimization of reinforced concrete building by simulated annealing. Comput-Aided Civ Inf 23(8):596â610PayĂĄ-Zaforteza I, Yepes V, Hospitaler A, GonzĂĄlez-Vidosa F (2009) CO2-efficient design of reinforced concrete building frames. Eng Struct 31(7):1501â1508Saassouh B, Lounis Z (2012) Probabilistic modeling of chloride-induced corrosion in concrete structures using first- and second-order reliability methods. Cement Concrete Comp 34(9):1082â1093The Concrete Centre (2009) The Concrete Industry Sustainability Performance Report. The Concrete Center, Camberley: http://www.admixtures.org.uk/downloads/Concrete%20Industry%20Sustainable%20Performance%20Report%202009.pdf , accessed 9 September 2012Tuutti K (1982) Corrosion of steel in Concrete. CBI Forskning Research Report, Swedish Cem Concr Res Inst. Stockholm, SwedenWeil M, Jeske U, Schebek L (2006) Closed-loop recycling of construction and demolition waste in Germany in view of stricter environmental threshold values. Waste Manage Res 24(3):197â206World Steel Association (2010) Fact sheet: the three Rs of sustainable Steel. World Steel Association, Brussels: http://www.steel.org/Sustainability/~/media/Files/SMDI/Sustainability/3rs.ashx , accessed 15 September 2012Worrell E, Price L, Martin N, Hendriks C, Meida LO (2001) Carbon dioxide emissions from the global cement industry. Annu Rev Energy Environ 26:303â329Yepes V, GonzĂĄlez-Vidosa F, AlcalĂĄ J, Villalba P (2012) CO2-optimization design of reinforced concrete retaining walls based on a VNS-threshold acceptance strategy. J Comput Civ Eng 26(3):378â386Yiwei T, Qun Z, Jian G (2011) Study on the Life-cycle Carbon Emission and Energy-efficiency Management of the Large-scale Public Buildings in Hangzho. China. International Conference on Computer and Management, Wuhan, pp 546â552Zornoza E, PayĂĄ J, MonzĂł J, Borrachero MV, GarcĂ©s P (2009) The carbonation of OPC mortars partially substituted with spent fluid catalytic catalyst (FC3R) and its influence on their mechanical properties. Const Build Mater 23(3):1323â132
Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV
The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of âs = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pTâ„20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60â€pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2â€{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration
Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector
The inclusive and dijet production cross-sections have been measured for jets
containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass
energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The
measurements use data corresponding to an integrated luminosity of 34 pb^-1.
The b-jets are identified using either a lifetime-based method, where secondary
decay vertices of b-hadrons in jets are reconstructed using information from
the tracking detectors, or a muon-based method where the presence of a muon is
used to identify semileptonic decays of b-hadrons inside jets. The inclusive
b-jet cross-section is measured as a function of transverse momentum in the
range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet
cross-section is measured as a function of the dijet invariant mass in the
range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets
and the angular variable chi in two dijet mass regions. The results are
compared with next-to-leading-order QCD predictions. Good agreement is observed
between the measured cross-sections and the predictions obtained using POWHEG +
Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet
cross-section. However, it does not reproduce the measured inclusive
cross-section well, particularly for central b-jets with large transverse
momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final
version published in European Physical Journal
- âŠ