Academic literature on the topic 'Associated surface form'
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Journal articles on the topic "Associated surface form"
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Turov, V. V., P. P. Gorbyk, T. V. Krupska, S. P. Turanska, V. F. Chekhun, and N. Yu Luk'yanova. "Composite systems for medical purposes, created on the basis of hydrophobic silica." Surface 13(28) (December 30, 2021): 246–75. http://dx.doi.org/10.15407/surface.2021.13.246.
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Composite systems with certain cytotoxic (AM1/lectin) and adsorption (AM1/gelatin) activity have been developed on the basis of methyl silica and protein molecules – lectin and gelatin. For both types of composites, mechanisms of water binding to the surface and methods of transferring of hydrophobic materials into the aquatic environment have been investigated. The state of interfacial water in air, organic and acid media was studied. It has been found that the presence of a hydrophobic component in composites stabilizes of surface water in a weakly associated state, when a significant part of water molecules does not form hydrogen bonds. Liquid hydrophobic medium enhances this effect, and the strong acid (trifluoroacetic), added to it, promotes the transition of water to a strongly associated state. It has been shown that the redistribution of water in the interparticle intervals of AM1 with protein molecules immobilized on their surface changes under the influence of mechanical loads. Mechanoactivated samples are characterized by the possibility of water penetration into the spaces between the primary particles of methyl silica. It has been shown that immobilization of lectin on the surface of AM1 is accompanied by an increase in the interfacial energy gS from 4.1 to 5.2 J/g. This is due to an increase in the concentration of strongly bound water. If we analyze the changes in the distributions of radii R of the clusters of adsorbed water, we can state that in the water adsorbed by native lectin molecules, there are two main maxima at R = 1 and 3 nm. In the immobilized state, the maximum at R = 1 nm is present in both types of water (of different order), but the second maximum is observed only for more ordered associates.
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Keum, Jong Hae. "Every algebraic Kummer surface is the K3-cover of an Enriques surface." Nagoya Mathematical Journal 118 (June 1990): 99–110. http://dx.doi.org/10.1017/s0027763000003019.
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A Kummer surface is the minimal desingularization of the surface T/i, where T is a complex torus of dimension 2 and i the involution automorphism on T. T is an abelian surface if and only if its associated Kummer surface is algebraic. Kummer surfaces are among classical examples of K3-surfaces (which are simply-connected smooth surfaces with a nowhere-vanishing holomorphic 2-form), and play a crucial role in the theory of K3-surfaces. In a sense, all Kummer surfaces (resp. algebraic Kummer surfaces) form a 4 (resp. 3)-dimensional subset in the 20 (resp. 19)-dimensional family of K3-surfaces (resp. algebraic K3 surfaces).
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Robaszewska, Maria. "On some flat connection associated with locally symmetric surface." Annales Universitatis Paedagogicae Cracoviensis. Studia Mathematica 13, no. 1 (December 1, 2014): 19–43. http://dx.doi.org/10.2478/aupcsm-2014-0003.
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Abstract For every two-dimensional manifold M with locally symmetric linear connection ∇, endowed also with ∇-parallel volume element, we construct a flat connection on some principal fibre bundle P(M,G). Associated with - satisfying some particular conditions - local basis of TM local connection form of such a connection is an R(G)-valued 1-form build from the dual basis ω1, ω2 and from the local connection form ω of ▽. The structural equations of (M,∇) are equivalent to the condition dΩ-Ω∧Ω=0. This work was intended as an attempt to describe in a unified way the construction of similar 1-forms known for constant Gauss curvature surfaces, in particular of that given by R. Sasaki for pseudospherical surfaces.
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Beiu, Valeriu, Leonard Dăuş, Marilena Jianu, Adela Mihai, and Ion Mihai. "On a Surface Associated with Pascal’s Triangle." Symmetry 14, no. 2 (February 19, 2022): 411. http://dx.doi.org/10.3390/sym14020411.
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An open problem in reliability theory is that of finding all the coefficients of the reliability polynomial associated with particular networks. Because reliability polynomials can be expressed in Bernstein form (hence linked to binomial coefficients), it is clear that an extension of the classical discrete Pascal’s triangle (comprising all the binomial coefficients) to a continuous version (exhibiting infinitely many values in between the binomial coefficients) might be geometrically helpful and revealing. That is why we have decided to investigate the geometric properties of a continuous extension of Pascal’s triangle including: Gauss curvatures, mean curvatures, geodesics, and level curves, as well as their symmetries.
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Pegna, Joseph, and Franz-Erich Wolter. "Surface Curve Design by Orthogonal Projection of Space Curves Onto Free-Form Surfaces." Journal of Mechanical Design 118, no. 1 (March 1, 1996): 45–52. http://dx.doi.org/10.1115/1.2826855.
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A novel technique for designing curves on surfaces is presented. The design specifications for this technique derive from other works on curvature continuous surface fairing. Briefly stated, the technique must provide a computationally efficient method for the design of surface curves that is applicable to a very general class of surface formulations. It must also provide means to define a smooth natural map relating two or more surface curves. The resulting technique is formulated as a geometric construction that maps a space curve onto a surface curve. It is designed to be coordinate independent and provides isoparametric maps for multiple surface curves. Generality of the formulation is attained by solving a tensorial differential equation formulated in terms of local differential properties of the surfaces. For an implicit surface, the differential equation is solved in three-space. For a parametric surface the tensorial differential equation is solved in the parametric space associated with the surface representation. This technique has been tested on a broad class of examples including polynomials, splines, transcendental parametric and implicit surface representations.
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Jiang, Muwei, Han Xie, Jinyu Zhu, Hao Ma, Naiqing Zheng, Siqi Li, Jiahui Xiao, Yirou Wang, Linjun Cai, and Xiaoxia Han. "Molecular form-specific immunoassays for neutrophil gelatinase-associated lipocalin by surface-enhanced Raman spectroscopy." Sensors and Actuators B: Chemical 297 (October 2019): 126742. http://dx.doi.org/10.1016/j.snb.2019.126742.
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Froeliger, Eunice H., and Paula Fives-Taylor. "Streptococcus parasanguisFimbria-Associated Adhesin Fap1 Is Required for Biofilm Formation." Infection and Immunity 69, no. 4 (April 1, 2001): 2512–19. http://dx.doi.org/10.1128/iai.69.4.2512-2519.2001.
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ABSTRACT The sanguis streptococci are primary colonizers of the tooth surface and thus form the foundation for the complex multiple species biofilm known as dental plaque. In addition, these bacteria can colonize native and prosthetic heart valves and are a common cause of endocarditis. Little is known about the molecular mechanisms governing multiple or single species biofilm development within this group of organisms. Using an in vitro assay for biofilm formation, we determined that (i) Streptococcus parasanguis FW213 can form biofilms on inert surfaces such as polystyrene and (ii) environmental and nutritional factors, such as glucose, affect S. parasanguisbiofilm formation. Several isogenic mutants of FW213 were tested in the biofilm assay. Strains containing mutations in fap1, a gene encoding a protein required for assembly of fimbriae, were deficient in biofilm formation. Mutants defective in recA, PepO endopeptidase activity, or the production of a fimbriae-associated protein, FimA, were still capable of biofilm formation. Phase-contrast microscopy was used to follow biofilm development by wild-type andfap1 mutant strains on plastic coverslips over time. Wild-type FW213 attached to the surface, formed aggregates of cells, and eventually formed a dense layer of cells that included microcolonies. In contrast, few fap1 mutant cells were observed attached to the surface, and no cell aggregates or microcolonies were formed. These results suggest that the long peritrichous fimbriae of FW213 are critical for the formation of biofilms on solid surfaces.
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Chandra, Jyotsna, Jasmine D. Patel, Jian Li, Guangyin Zhou, Pranab K. Mukherjee, Thomas S. McCormick, James M. Anderson, and Mahmoud A. Ghannoum. "Modification of Surface Properties of Biomaterials Influences the Ability of Candida albicans To Form Biofilms." Applied and Environmental Microbiology 71, no. 12 (December 2005): 8795–801. http://dx.doi.org/10.1128/aem.71.12.8795-8801.2005.
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ABSTRACT Candida albicans biofilms form on indwelling medical devices (e.g., denture acrylic or intravenous catheters) and are associated with both oral and invasive candidiasis. Here, we determined whether surface modifications of polyetherurethane (Elasthane 80A [E80A]), polycarbonateurethane, and poly(ethyleneterephthalate) (PET) can influence fungal biofilm formation. Polyurethanes were modified by adding 6% polyethylene oxide (6PEO), 6% fluorocarbon, or silicone, while the PET surface was modified to generate hydrophilic, hydrophobic, cationic, or anionic surfaces. Formation of biofilm was quantified by determining metabolic activity and total biomass (dry weight), while its architecture was analyzed by confocal scanning laser microscopy (CSLM). The metabolic activity of biofilm formed by C. albicans on 6PEO-E80A was significantly reduced (by 78%) compared to that of biofilm formed on the nonmodified E80A (optical densities of 0.054 ± 0.020 and 0.24 ± 0.10, respectively; P = 0.037). The total biomass of Candida biofilm formed on 6PEO-E80A was 74% lower than that on the nonmodified E80A surface (0.46 ± 0.15 versus 1.76 ± 0.32 mg, respectively; P = 0.003). Fungal cells were easily detached from the 6PEO-E80A surface, and we were unable to detect C. albicans biofilm on this surface by CSLM. All other surface modifications allowed formation of C. albicans biofilm, with some differences in thearchitecture. Correlation between contact angle and biofilm formation was observed for polyetherurethane substrates (r = 0.88) but not for PET biomaterials (r = −0.40). This study illustrates that surface modification is a viable approach for identifying surfaces that have antibiofilm characteristics. Investigations into the clinical utility of the identified surfaces are warranted.
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Tang, Peifu, Wei Zhang, Yan Wang, Boxun Zhang, Hao Wang, Changjian Lin, and Lihai Zhang. "Effect of Superhydrophobic Surface of Titanium onStaphylococcus aureusAdhesion." Journal of Nanomaterials 2011 (2011): 1–8. http://dx.doi.org/10.1155/2011/178921.
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Despite the systemic antibiotics prophylaxis, orthopedic implants still remain highly susceptible to bacterial adhesion and resulting in device-associated infection. Surface modification is an effective way to decrease bacterial adhesion. In this study, we prepared surfaces with different wettability on titanium surface based on TiO2nanotube to examine the effect of bacterial adhesion. Firstly, titanium plates were calcined to form hydrophilic TiO2nanotube films of anatase phase. Subsequently, the nanotube films and inoxidized titaniums were treated with 1H, 1H, 2H, 2H-perfluorooctyl-triethoxysilane (PTES), forming superhydrophobic and hydrophobic surfaces. Observed by SEM and contact angle measurements, the different surfaces have different characteristics.Staphylococcus aureus(SA) adhesion on different surfaces was evaluated. Our experiment results show that the superhydrophobic surface has contact angles of water greater than 150∘and also shows high resistance to bacterial contamination. It is indicated that superhydrophobic surface may be a factor to reduce device-associated infection and could be used in clinical practice.
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Rogalski, A. A., and S. J. Singer. "An integral glycoprotein associated with the membrane attachment sites of actin microfilaments." Journal of Cell Biology 101, no. 3 (September 1, 1985): 785–801. http://dx.doi.org/10.1083/jcb.101.3.785.
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An integral membrane protein associated with sites of microfilament-membrane attachment has been identified by a newly developed IgG1 monoclonal antibody. This antibody, MAb 30B6, was derived from hybridoma fusion experiments using intact mitotic cells of chick embryo fibroblasts as the immunization vehicle as well as the screening probe for cell surface antigens. In immunofluorescent experiments with fixed cells, MAb 30B6 surface labeling is uniquely correlated with microfilament distributions in the cleavage furrow region of dividing chick embryo fibroblasts and cardiac myocytes in culture. The MAb 30B6 antigen in addition is associated with microfilament-membrane attachment sites in interphase fibroblasts at the dorsal surface, the adhesion plaque region at the ventral surface, and at junction-like regions of cell-cell contact. It is also found co-localized with the membrane-dense plaques of smooth muscle. The MAb 30B6 antigen is expressed in a wide number of chicken cell types (particularly smooth muscle cells, platelets, and endothelial cells), but not in erythrocytes. Some of the molecular characteristics of the MAb 30B6 antigen have been determined from immunoblotting, immunoaffinity chromatography, immunoprecipitation, cell extraction, and charge shift electrophoresis experiments. It is an integral sialoglycoprotein with an apparent molecular mass of 130 kD (reduced form)/107 kD (nonreduced form) in SDS PAGE. Another prominent glycoprotein species with an apparent molecular mass of 175 kD (reduced form)/165 kD (nonreduced form) in SDS PAGE is co-isolated on MAb 30B6 affinity columns, but appears to be antigenically distinct since it is not recognized by MAb 30B6 in immunoblotting or immunoprecipitation experiments. By virtue of its surface distributions relative to actin microfilaments and its integral protein character, we propose that the MAb 30B6 antigen is an excellent candidate for the function of directly or indirectly anchoring microfilaments to the membrane.
Dissertations / Theses on the topic "Associated surface form"
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McCarthy, Erik L. "Selective Biomolecular Layers for Surface-associated Rolling Circle Amplification." Fogler Library, University of Maine, 2006. http://www.library.umaine.edu/theses/pdf/McCarthyEL2006.pdf.
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Tennant, Ian. "Antibody-based strategies for identifying novel apoptotic-cell surface-associated molecules." Thesis, University of Edinburgh, 2005. http://hdl.handle.net/1842/29395.
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Defective clearance of apoptotic cells (ACs) is linked to autoimmune and inflammatory disease states such as systemic lupus erythematosus and cystic fibrosis. Relatively few markers exist for the ‘eat me’ signals displayed on the AC surface despite the great potential for such molecules as diagnostic or therapeutic reagents. In this work various antibody-based strategies were employed in an attempt to identify novel AC-specific epitopes. An initial strategy utilised a phage displayed antibody library containing a repertoire of ~108 antibody fragments encoded by human germline genes as an unbiased source of binding specificity. An alternative approach was based on the knowledge that receptors used by macrophages to recognise ACs also recognise pathogen-associated molecules. By looking for the ability of antibodies raised against pathogens to cross-react with ACs the hypothesis that cells undergoing apoptosis reveal molecular patterns that resemble those on pathogen related structures was tested. Screening of antibodies raised in vivo, that have previously been characterised as having specificity for pathogen-associated molecular patterns (PAMPs) revealed that some cross-react with cells undergoing apoptosis. One of these antibodies was found to bind an epitope found on the ubiquitously expressed ~40KDa precursor to Laminin-Binding-Protein (LBP/p40). These findings suggest that epitopes resembling PAMPs appear on the surface of mammalian cells as a result of apoptosis and that these epitopes can be found on endogenously expressed molecules which are normally excluded from the surface of viable cells. The ability of host receptors to cross-react with host and pathogen-associated epitopes in this way may lead to a greater understanding of the mechanisms of autoimmune reactions and allow design of approaches to stimulate the immune system for the treatment of cancer.
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Hathaway, Hollie. "Biomodification of abiotic surfaces for the prevention of hospital-associated infection." Thesis, University of Bath, 2017. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.760935.
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This research aims to investigate the application of medical biotechnology with regard to the detection and treatment of hospital-associated infection. Various strategies focused on the implementation of biological detection agents and biotherapeutics are discussed, with particular emphasis placed on surface-anchoring technologies. This thesis is presented in the alternative format, consisting of published research papers embedded within the text. An extended introduction precedes each publication and a reflective commentary accompanies each research paper. For the purpose of continuity, all figure captions and references are in keeping with the body of the text. Part A concerns the detection of residual sources of transmissible infection, via the utilisation of an enzymatic detection agent, capable of modelling clinical surface contamination post sterilisation. Chapter 1 details the development of a current clinical biosensor, focused on modification of polymeric substrates via plasma activation. Covalent immobilisation facilitated enhanced proteinaceous surface retention, alongside retention of biological activity, potentially providing a more stringent assessment of hospital sterilisation measures. Chapter 2 (unpublished) investigates the possibility of protein engineering for further development of the aforementioned biosensor. This research focuses on genetic modification of the detection agent and subsequent covalent conjugation to a fluorescent reporting system, with the intention of quantifying surface contamination in the clinical setting. Part B focuses on the development of potential biological therapeutics for the treatment of infection. Chapter 3 aims to provide the theoretical background to the proceeding research in the form of a review paper. Chapter 4 concerns the utilisation of surface-anchored, polymeric nanoparticles as delivery vectors for bacteriophage, facilitating the controlled delivery of the antimicrobial cargo at an elevated temperature associated with chronic wound infection. Chapter 5 is presented as an extension of the preceding research, detailing the use of a synergistic enzybiotic cocktail as oppose to bacteriophage, in an attempt to alleviate certain regulatory concerns.
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PEIXOTO, ARUQUIA BARBOSA MATOS. "AN APPROXIMATION SCHEME FOR IMPLICIT SURFACES BY REDENING THE ASSOCIATED OCTREE POINTS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2013. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=37195@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
Neste trabalho é apresentado um método adaptativo de poligonalização de superfícies implícitas, a Grade Adaptativa, associado a uma octree como estrutura de dados. Os pontos da subdivisão dos cubos dessa octree não estão sempre no centro, como na definição clássica, porém mais próximos à superfície. Para obter essa característica, os valores da função são considerados na região de poligonalização. Os pontos da malha que aproximam a superfície são conectados utilizando as arestas dos cubos referentes às folhas dessa octree. As arestas pertencentes à interseção de três ou quatro cubos são testadas com relação a sua intersecção pela superfície. Elas são obtidas por meio de uma redefinição do conceito de Arestas Mínimas. O método apresentado nesta tese conduz a resultados mais precisos que aqueles obtidos com métodos em que a octree tenha sua subdivisão sempre no centro, como o Dual Contouring. O melhor posicionamento da grade torna possível captar mais detalhes com o mesmo nível de subdivisões, pois nesse caso há mais precisão no posicionamento dos vértices da malha e, além disso, mais cubos intersectam a superfície, gerando mais pontos da malha.
This work presents an adaptive method of polygonization for implicit surfaces, the Adaptive Grid, associated to an octree as a data structure. The octree cubes subdivision points are not always set in the center, as in the classical definition, but closer to the surface. In order to obtain this property, the values of the function are considered in the region of polygonization. The mesh points that approximate the surface are connected using the cubes edges related to the leaves in the octree. The edges that belong to the intersection of three or four cubes are tested regarding to its intersection with the surfaces. They are obtained by a redefinition of the Minimal Edges algorithm. The method presented in this work leads to more precise results than the methods for which the octree has its subdivision always in the center, as Dual Contouring. The better positioning of the grid allows to capture more details with the same subdivision level, because in this case there is more accuracy in the mesh vertex positioning and moreover, more cubes intersect the surface, generating more mesh points.
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A, Abdul Malik Shareen. "Defence on surface of Rhodophyta Halymenia floresii : metabolomic profile and interactions with its surface-associated bacteria." Electronic Thesis or Diss., Lorient, 2020. http://www.theses.fr/2020LORIS598.
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Halymenia floresii, une Rhodophycée présente une surface remarquablement exempte d'épiphytes dans les conditions de l'Aquaculture MultiTrophique Intégrée (AMTI). Ce phénomène traduit la présence potentielle en surface de composés actifs allélopathiques. L'objectif de ce travail a été d'explorer les mécanismes de défense développés par H. floresii contre l'épibiose, de détecter et d'identifier les métabolites secondaires produits à la surface de l’algue et d'étudier les relations avec les bactéries épiphytes. Nous avons ainsi pu isoler la communauté épibactérienne de H. floresii cultivée dans des conditions contrôlées (AMTI) et non contrôlées (échantillons collectés in situ). Les épibactéries isolées ont été criblées in vitro pour analyser les signaux de détection de Quorum Sensing (QS). Les extraits produits en surface ont été analysés pour détecter toute interférence avec le Quorum Sensing. Les épibactéries pathogènes et non-pathogènes ont été différenciées par leur capacité à induire une maladie algale, le blanchiment. Vibrio owensii, ainsi que son signal C4-HSL QS, a été identifié comme pathogène opportuniste induisant un blanchiment. Les métabolites extraits de la surface et de cellules entières de H. floresii ont été analysés par LC-MS. Une base de données a été constituée à partir d’une analyse métabolomique non ciblée. Quarante et un métabolites actifs ont été identifiés, parmi lesquels les composés halogénés, des furanones et divers inhibiteurs étaient surreprésentés. Fait intéressant, les deux premières classes sont connues comme de puissants composés interférant avec le QS. La présence relativement élevée de métabolites allélopathiques à la surface de H. floresii soutient fortement l'hypothèse selon laquelle ils doivent être impliqués dans la protection de l'hôte. Des recherches supplémentaires seront nécessaires pour explorer l’ensemble des métabolites secondaires produits par H. floresii et leurs rôles chez l’algueThe surface of Halymenia floresii, a Mexican Rhodophyta, was observed to be remarkably free of epiphytes under Integrated MultiTrophic Aquaculture (IMTA) conditions. This suggests the presence of allelopathic active compounds released by this macroalgae. The aim of this work was to explore the defence mechanisms developed by H. floresii against surface epibiosis, to detect and identify the secondary metabolites produced at the surface of the algae, and to study its relation with surface associated bacteria. For the first time, we isolated the epibacterial community of H. floresii cultivated under controlled conditions (IMTA) and uncontrolled ones (beach-cast material collected in the area). The isolated epibacteria were screened in vitro to analyse Quorum Sensing (QS) signals, and others H. floresii surface extracts were assayed for any QS interference with them. We differentiated the epibacteria significant pathogens from the non- pathogens ones by their ability to induce bleaching, a well-known algal disease. Vibrio owensii was identified as an opportunistic pathogen inducing bleaching in H. floresii which was also associated to the presence of its C4-HSL QS signal. The surface and whole cell metabolites extracts from H. floresii specimens cultivated under controlled conditions were analysed by means of LC/MS. An untargeted metabolomic analysis of H. floresii was performed to provide a global metabolic profile as a first database. We identified ‘41’ active metabolites in H. floresii, among which halogenated compounds, furanones and various inhibitors were overrepresented. Interestingly, the first two classes are well known potent QS interfering compounds. The relatively higher occurrences of allelopathic metabolites at the surface of H. floresii strongly supports the hypothesis that they must be involved in the host protection. Further investigations are needed to explore the secondary metabolites of H. floresii et their role in the seaweed
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Kazemzadeh-Narbat, Mehdi. "Local delivery of antimicrobial peptides from titanium surface for the prevention of implant-associated infections." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44017.
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Titanium (Ti) is a key biomedical material extensively used in orthopaedic implants. Prevention of implant-associated infections has been one of the main challenges in orthopaedic surgery. This challenge is further complicated by the concern over the development of antibiotic resistance as a result of using traditional antibiotics for infection prophylaxis. One of the promising alternatives is the family of antimicrobial peptides (AMPs). The present dissertation develops progressive approaches that enable the loading and local delivery of a unique group of cationic antimicrobial peptides through titanium implant surfaces.
In the first technique, a thin layer of micro-porous calcium phosphate (CaP) coating was processed by electrolytic deposition onto the surface of titanium as the drug carrier. The AMP-loaded CaP coating was not cytotoxic for MG-63 osteoblast-like cells, and the implants showed high antimicrobial activity against both Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa) bacteria with 10⁶-fold reductions of both bacterial strains within 30 min and ∼92% and ∼77% inhibition of luminescence at 4 h and 24 h, respectively.
Second study investigated the in vitro AMP release, antimicrobial performance, and cytotoxicity of a modified Tet213 (HHC36), as well as the in vivo bone growth of AMP loaded into calcium phosphate coated Ti implants in a rabbit model. Burst release during the first few hours followed by a slow and steady release for 7 days was observed. In vivo bone growth study showed that loading of AMP did not impair bone growth onto the implants.
In the last study multilayer thin films of titania nanotubes (NT) and CaP coatings were formulated with AMP and were topped with a thin phospholipid film similar to cell membrane. The films were shown to be non-cytotoxic, hydrophilic, with the potential of tuning loading and release kinetics of AMP. The best model describing the AMP release was first-order model.
The first two approaches demonstrated a promising method for an early stage peri-implant infection treatment. The last study proposed a technique to improve the kinetics of AMP release and total loaded AMP quantity, and to increase the Ti interfacial strength while maintain the osteconductivity by applying CaP coating.
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Моравецька, Катерина Вiталiївна. "Мiри на банахових многовидах з рiвномiрною структурою." Doctoral thesis, Київ, 2018. https://ela.kpi.ua/handle/123456789/26061.
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Дисертацiя присвячена диференцiйовним мiрам на банахових многовидах
з рiвномiрною структурою.
Запропоновано метод побудови асоцiйованих мiр на поверхнях скiнченної
корозмiрностi, вкладених у банахiв многовид з рiвномiрною структурою. Введено поняття асоцiйованої диференцiальної форми поверхнi та строго трансверсального до поверхнi набору векторних полiв. Доведено теорему “про узгодженiсть”, згiдно з якою поверхнева мiра задається однозначно асоцiйованою
диференцiальною формою поверхнi. Показано транзитивнiсть запропонованої
конструкцiї. На прикладi мiри Лебега в скiнченновимiрному просторi Rn та
мiри об’єму на рiмановому многовидi з рiвномiрною структурою обґрунтовано її адекватнiсть.
Отримано узагальнення низки результатiв з теорiї диференцiйовних мiр на
лiнiйних просторах на випадок банахових многовидiв з рiвномiрною структурою. Доведено критерiй слабкої диференцiйовностi мiри уздовж обмеженого
векторного поля, що узагальнює вiдомий результат В. I. Богачова.
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Jordão, Nuno Ricardo de Oliveira. "Study of the cell surface proteome for the analysis of Parkinson’s disease associated DJ-1 mutations." Master's thesis, Universidade de Aveiro, 2015. http://hdl.handle.net/10773/15483.
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Mestrado em Biotecnologia - Biotecnologia MolecularParkinson’s disease (PD) is a neurodegenerative disease, characterized with selective neurodegeneration and dopamine depletion. Despite most cases appear to have sporadic origin, it has been associated various monogenic mutations to the onset of a parkinsonian phenotype. DJ-1 protein is of particular interest given its neuroprotective role against oxidative stress and mitochondria impairment, and the identification of several mutations correlated with early onset PD. For this study, it were then produced two pathological mutations of DJ-1, M26I and E163K. SDS-PAGE and LC-MS/MS analysis confirmed the adequate production and purification of the both mutant proteins, and SEC-HPLC secured the structural perseverance of the mutations as homodimers, a key feature of DJ-1 essential for its biological activity. On the other hand, SH-SY5Y viability assays indicated that despite the native form protective role against oxidative stress, M26I and E163K mutations showed a compromised neuroprotective capacity. To better understand the reasons for this biological impairment, it was developed a protocol for cell surface proteins labelling with Sulfo-NHSLC-biotin and avidin pull-down for enrichment and downstream MS analysis. Assays such as western blotting, LC-MS/MS and confocal microscopy confirmed the adequacy of the proposed procedure. When applied for the analysis of proteome variations related to oxidative stress, in enriched fractions from SH-SY5Y biotinylation and avidin pull-down of crude membrane sub cellular part, it allowed the identification of several proteins of interest, namely four proteins with significant difference caused by oxidative stress induction, and of other proteins of interest. It was also performed the direct pull-down of whole protein extract, offering inconclusive results regarding the preferential use of ultracentrifugation before pull-down. Nevertheless, it was the first time that SH-SY5Y cell surface was analysed in a PD context, and it could be used in the future to study cell surface proteome alterations modulated by oxidative stress and extracellular presence of native or mutant DJ-1, providing new insights regarding its intake and signalling modulation in pathological conditions, and hence contributing for a new perspective over preventive or eliciting mechanisms associated to the onset of Parkinson’s disease.
A doença de Parkinson é uma doença neurodegenerativa caracterizada por uma neurodegeneração selectiva e depleção de dopamina, e apesar de grande parte dos casos terem origem esporádica diversas mutações monogénicas têm sido associadas ao desenvolvimento de um fenótipo parkinsoniano. A proteína DJ-1 é de particular interesse, dado o seu papel neuroprotector contra stress oxidativo e disfunção mitocondrial, e a identificação de mutações correlacionadas a doença de Parkinson precoce. Neste estudo, foram produzidas duas mutações patológicas da proteína DJ-1, M26I e E163K. Uma análise SDS-PAGE e LC-MS/MS comprovou uma produção e purificação adequada das mutações, e SEC-HPLC assegurou a preservação estrutural das mutações de DJ-1 como homodímeros, uma característica chave de DJ-1 fundamental para a sua actividade biológica. Por outro lado, estudos de viabilidade de SH-SY5Y indicaram que, apesar do papel protector da forma nativa contra stress oxidativo, as mutações M26I e E163K demonstraram uma reduzida capacidade neuroprotectiva. Para melhor compreender os motivos desta disfunção biológica, foi desenvolvido um protocolo para marcação das proteínas de superfície celular com Sulfo-NHS-LC-biotina e pull-down com avidina para enriquecimento e subsequente análise MS. Vários ensaios como western blotting, LC-MS/MS e microscopia confocal confirmaram a adequação do protocolo sugerido. Quando aplicado para uma análise de variações proteómicas relacionadas com stress oxidativo, em fracções enriquecidas provenientes da biotinilação de SH-SY5Y e pull-down da parte membranar do extracto celular, permitiu a identificação de várias proteínas de interesse, nomeadamente quatro proteínas com diferença significativa resultante da indução de stress oxidativo. Também foi realizado um pull-down com a totalidade extracto celular, que resultou em dados não conclusivos relativamente ao uso de ultracentrifugação antes do pull-down. Não obstante, este estudo correspondeu à primeira análise da superfície celular de SH-SY5Y realizada num contexto da doença de Parkinson, que poderá ser usada no futuro para estudar alterações no proteoma de superfície celular em ambiente de stress oxidativo e de adição da proteína DJ-1, na forma nativa e mutante, de forma a fornecer novas pistas referentes ao seu intake e modulação da sinalização em ambiente oxidativo, e em suma contribuindo para uma nova perspectica sobre os mecanismos protectores ou despoletadores da doença de Parkinson.
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Vargas, Vallejo Michel Eduardo. "Nanoscale structural/chemical characterization of manganese oxide surface layers and nanoparticles, and the associated implications for drinking water." Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/64514.
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Water treatment facilities commonly reduce soluble contaminants, such as soluble manganese (Mn2+), in water by oxidation and subsequent filtration. Previous studies have shown that conventional porous filter system removes Mn2+ from drinking water by developing Mn-oxides (MnOx(s)) bearing coating layers on the surface of filter media. Multiple models have been developed to explain this Mn2+ removal process and the formation mechanism of MnOx(s) coatings. Both, experimental and theoretical studies to date have been largely focused on the micrometer to millimeter scale range; whereas, coating layers are composed of nanoscale particles and films. Hence, understanding the nanoscale particle and film formation mechanisms is essential to comprehend the complexity of soluble contaminant removal processes. The primary objective of this study was to understand the initial MnOx(s) coating formation mechanisms and evaluate the influence of filter media characteristics on these processes. We pursued this objective by characterizing at the micro and nanoscale MnOx(s) coatings developed on different filter media by bench-scale column tests with simulating inorganic aqueous chemistry of a typical coagulation fresh water treatment plant, where free chlorine is present across filter bed. Analytical SEM and TEM, powder and synchrotron-based XRD, XPS, and ICPMS were used for characterization of coatings, filter media and water solution elemental chemistry. A secondary objective was to model how surface coating formation occurred and its correlation with experimentally observed physical characteristics. This modeling exercise indicates that surface roughness and morphology of filtering media are the major contributing factors in surface coating formation process. Contrary to previous models that assumed a uniform distribution and growth of surface coating, the experimental results showed that greater amounts of coating were developed in rougher areas. At the very early stage of coating formation, unevenly distributed thin films and/or particle aggregates were observed, which provided active sites for further surface coating growth. The predominant MnOx(s) phase in the surface coatings was identified to be poorly crystalline birnessite having scavenging activity by intercalation and/or sorption. This would explain the enhancement of efficiency in removing soluble manganese and other contaminants during water filtration. Moreover, the increased Mn2+ removal effect of having aluminum (Al) in pre-treated water is explained. These results indicate that the surface roughness and morphology need to be incorporated into particle capture models to more precisely describe the soluble manganese removal process.Ph. D.
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Frontino, Gina Christine. "Comparison of Methods for Detection of Listeria on Wooden Shelves used for Cheese Aging: Challenges Associated with Sampling Porous Surfaces." ScholarWorks @ UVM, 2019. https://scholarworks.uvm.edu/graddis/1008.
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This thesis examined the efficacy of various sampling and detection methods used for environmental monitoring of Listeria species on wooden surfaces used for cheese aging. Government agencies including the Food and Drug Administration (FDA) and United States Department of Agriculture (USDA) recommend enrichment methods coupled with use of environmental sponges and swabs. Our study compared efficacy of sponge swabs manufactured by 3M™ and World Bioproducts. There is a lack of research validating the best performing swab type and enrichment method combination that is sensitive when used on rough, porous surfaces. The sensitivity of these environmental sampling tools and methods are critical considerations to effectively monitor the presence of Listeria species on wooden boards used during aging of artisan cheese.
Seasoned spruce wooden shelves, cut into 100cm2 replicates, were spot inoculated with varying concentrations of Listeria species inocula, the Listeria species strains consisted of two L. monocytogenes strains and a Green Florescence Protein (GFP) expressing strain of L. innocua. The inoculated wooden surface was swabbed with three environmental sampling sponge/swab formats (World Bioproducts© EZ ReachTM environmental swabs (WBEZ) with HiCap (WBHC) and Dey-Engley (WBDE) neutralizing broths; and 3MTM environmental swabs (3MTM) with Dey-Engley neutralizing broth). Enumeration methods were used to determine the low target limits of detection. Once the low target concentrations were identified, five enrichment methods consisting of 3MTM Listeria Environmental Plate, FDA, Dual Enrichment, modified USDA, and modified FDA were challenged against low concentrations of Listeria species inocula (0.01 cfu/cm2, 0.1 cfu/cm2, 1 cfu/cm2) and the three environmental sponge swab formats. Performance of the swab formats was assessed by collection of naturally contaminated environmental samples (n=405) from dairy farm environments, swabbing where wooden surfaces existed, and analyzed using the most effective enrichment methods found from previous experiments. Lastly, the wooden surfaces and sponge swabs were observed under a Florescent Microscope using GFP L. innocua to visually determine how each sponge material of the 3M™ and World Bioproducts recovered the inocula.
When wood surfaces were inoculated at high concentration levels of Listeria spp., all swab formats performed equally for detecting Listeria. Success of positive recovery at low concentrations was variable, where enrichment methods and swabs were not dependent on each other. The swab format that worked best for detecting low levels of Listeria species was the WBDE sponge swab. The WBDE swab also performed the best in dairy farm environmental sampling. The m-USDA enrichment method was found to be most effective in recovery and repair of low and potentially injured Listeria spp. Wooden surfaces are rough and porous and should be taken into consideration when creating an environmental sampling plan for these food contact surfaces. All swabs and methods performed with only slight variation, but the variation could be significant when monitoring wooden shelves with low level contamination of Listeria species. Artisan cheesemakers who use wooden shelves during the aging of their cheese, should ensure use of the most sensitive detection methods.
Books on the topic "Associated surface form"
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Nominations of Linda J. Morgan, to be a member of the Surface Transportation Board; and Stephen D. Van Beek, to be Associate Deputy Secretary and Director, Office of Intermodalism, and Michael J. Frazier, to be Assistant Secretary for Government [i.e. Governmental] Affairs, of the U.S. Department of Transportation: Hearing before the Committee on Commerce, Science, and Transportation, United States Senate, One Hundred Sixth Congress, first session, September 28, 1999. Washington: U.S. G.P.O., 2002.
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Peng, Syd, ed. Surface Subsidence Engineering. CSIRO Publishing, 2020. http://dx.doi.org/10.1071/9781486312559.
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Underground coal mining disturbs both the overburden strata and the immediate floor strata. The subject of surface subsidence deals with the issues associated with the movement of overburden strata, which are the layers from the seam to the surface, where structures and water resources important to human activities are located.
Surface Subsidence Engineering provides comprehensive coverage of the major issues associated with surface subsidence. The chapters are written by experts on surface subsidence in the three leading coal producing and consuming countries in the world: Australia, China and the United States. They discuss general features and terminologies, subsidence prediction, subsidence measurement techniques, subsidence impact on water bodies, subsidence damage, mitigation and control, and subsidence on abandoned coal mines. In addition, the final chapter addresses some of the unique features of surface subsidence found in Australian coal mines. The book provides information on coal seams ranging from flat to gently inclined to steep to ultra-steep seams.
Written for mining engineers, geotechnical engineers and students of mining engineering, this book covers both theories and practices of surface subsidence. Unlike previous publications, it also deals with the subsidence impact on surface and groundwater bodies, crucial resources that are often neglected by subsidence researchers.
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Tuschl, Karin, Peter T. Clayton, and Philippa B. Mills. Disorders of Manganese Metabolism. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780199972135.003.0045.
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Manganese is an essential trace metal for numerous metalloenzymes. Manganese homeostasis requires tight regulation in vivo and disruption of this balance can lead to manganese overload and subsequent accumulation of manganese in brain, liver, and blood. Mutations in SLC30A10, a cell surface-localized manganese efflux transporter, cause an autosomal recessive hypermanganesemia syndrome with two distinct phenotypes: childhood onset dystonia and adult onset Parkinsonism, associated with chronic liver disease, polycythemia and features of iron depletion. MRI brain appearances are characteristic of Mn deposition with hyperintense basal ganglia on T1-weighted images. Chelation therapy with disodium calcium edetate and iron supplementation effectively lower blood manganese levels, halt liver disease progression and improve neurological symptoms.The inherited form of hypermanganesemia can be distinguished from acquired causes of manganese overload including environmental overexposure and acquired hepatocerebral degeneration in cases of end stage liver disease.
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Jayne, David. Treatment of ANCA-associated vasculitis. Oxford University Press, 2013. http://dx.doi.org/10.1093/med/9780199642489.003.0132.
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The goals of treatment in anti-neutrophil cytoplasm antibody (ANCA) vasculitis are to stop vasculitic activity, to prevent vasculitis returning, and to address longer-term comorbidities caused by tissue damage, drug toxicity, and increased cardiovascular and malignancy risk. Cyclophosphamide and high-dose glucocorticoids remain the standard induction therapy with alternative immunosuppressives, such as methotrexate or azathioprine, to prevent relapse. Refractory disease resulting from a failure of induction or remission maintenance therapy requires alternative agents and rituximab has been particularly effective. Replacement of cyclophosphamide by rituximab for remission induction is supported by recent evidence. Additional therapy with intravenous methylprednisolone and plasma exchange is employed in severe presentations with failing vital organ function. Drug toxicity contributes to comorbidity and mortality and has led to newer regimens with reduced cyclophosphamide exposure. Glucocorticoid toxicity remains a major problem, with controversy over the rapidity with which glucocorticoids can be reduced or withdrawn. Disease relapse occurs in 50% and requires early detection at a stage when it will not adversely affect outcomes. Rates of cardiovascular disease and malignancy are higher than in control populations but strategies to reduce their risk, apart from cyclophosphamide-sparing regimens, have not been developed. Thromboembolic events occur in 10% and may be linked to the recently identified autoantibodies to plasminogen and tissue plasminogen activator. Outcomes of vasculitis depend heavily on the level of tissue damage at diagnosis, especially renal dysfunction, but are also influenced by patient age, ANCA subtype, disease extent, and response to therapy. Eosinophilic granulomatosis with polyangiitis (Churg-Strauss)is treated along similar principles to granulomatosis with polyangiitis (GPA) and microscopic polyangiitis but the persistence of steroid-dependent asthma in over one-third and differences in pathogenesis has suggested alternative treatment approaches. Chronic morbidity results from tissue damage and is especially common in the upper and lower respiratory tract and kidneys. Tracheobronchial disease is a severe late complication of GPA, while deafness, nasal obstruction, and chronic sinusitis are sequelae of nasal and ear vasculitis. Chronic infection of damaged epithelial surfaces acts as a drive for vasculitic activity and adequate infection control is necessary for stable remission. Chronic kidney disease can stabilize for many years but the risks of endstage renal disease (ESRD) are increased by acute kidney injury at presentation or renal relapse. Renal transplantation is successful, with similar outcomes to other causes of ESRD.
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Henry G, Burnett, and Bret Louis-Alexis. Part II Key Risks and Disputes Associated with International Mining Projects, 7 Purchase and Joint Venture Disputes. Oxford University Press, 2017. http://dx.doi.org/10.1093/law/9780198757641.003.0007.
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This chapter discusses mineral rights and joint-venture disputes. The sale and purchase of an individual mining project will generally come down to the transfer of mineral rights. Disputes arising in connection with the transfer of mineral rights usually concern the validity and extent of the rights sold and, in particular, the conveyance of the surface rights associated with the project. Such disputes are often contractual in nature, and can be resolved through domestic or international arbitration. Joint ventures involve a relationship between two or more parties, one of which (the operator) will manage the joint venture for the benefit of its co-venturers. Disputes may arise in connection with the operations and management of the joint venture, particularly in purely contractual joint ventures. A frequent matter of contention is the definition of annual work programs and budget and their approval. Disputes may also emerge in connection with the buy-out and valuation of minority interests.
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Saxon, Leanne. Bone. Oxford University Press, 2013. http://dx.doi.org/10.1093/med/9780199533909.003.0006.
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Sports participation has numerous positive health benefits; however, it is also associated with an increased risk of injury. While bone injuries in sport are less frequent than ligament tears, contusions, or surface wounds, they can be debilitating for an athlete because of the time needed for recovery. In this chapter I describe the incidence and cost of bone injuries in sport, fundamentals of bone biology and repair, risk factors associated with fractures, stress fractures, and periostitis, and review both current and possible future recommendations for the treatment of bone-related injuries....
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Lee, Gregory. Epitope/Peptide-Based Monoclonal Antibodies for Immunotherapy of Ovarian Cancer. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780190248208.003.0007.
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Two monoclonal antibodies, RP215 and GHR106, were selected, respectively, for the research and development of anti-cancer drugs targeting ovarian cancer and other types of human cancer. RP215 was shown to react with a carbohydrate-associated epitope located mainly in the variable regions of immunoglobulin heavy chains expressed on the surface of almost all cancer cells in humans. GHR106 was generated against a synthetic peptide corresponding to N1-29 amino acid residues in the extracellular domains of human GnRH receptor, which is surface-expressed by most cancer cells as well as the anterior pituitary. This monoclonal antibody was shown to serve as a bioequivalent analog to GnRH-derived decapeptides currently used clinically. The molecular mechanisms of action of these two antibody-based anti-cancer drug candidates were well elucidated following numerous biochemical, immunological, and molecular biological studies, mainly by using ovarian cancer as the model. Further preclinical studies with humanized forms of these two antibodies are essential.
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Cook, Kerry H. Climate Change Scenarios and African Climate Change. Oxford University Press, 2018. http://dx.doi.org/10.1093/acrefore/9780190228620.013.545.
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Accurate projections of climate change under increasing atmospheric greenhouse gas levels are needed to evaluate the environmental cost of anthropogenic emissions, and to guide mitigation efforts. These projections are nowhere more important than Africa, with its high dependence on rain-fed agriculture and, in many regions, limited resources for adaptation. Climate models provide our best method for climate prediction but there are uncertainties in projections, especially on regional space scale. In Africa, limitations of observational networks add to this uncertainty since a crucial step in improving model projections is comparisons with observations. Exceeding uncertainties associated with climate model simulation are uncertainties due to projections of future emissions of CO2 and other greenhouse gases. Humanity’s choices in emissions pathways will have profound effects on climate, especially after the mid-century.The African Sahel is a transition zone characterized by strong meridional precipitation and temperature gradients. Over West Africa, the Sahel marks the northernmost extent of the West African monsoon system. The region’s climate is known to be sensitive to sea surface temperatures, both regional and global, as well as to land surface conditions. Increasing atmospheric greenhouse gases are already causing amplified warming over the Sahara Desert and, consequently, increased rainfall in parts of the Sahel. Climate model projections indicate that much of this increased rainfall will be delivered in the form of more intense storm systems.The complicated and highly regional precipitation regimes of East Africa present a challenge for climate modeling. Within roughly 5º of latitude of the equator, rainfall is delivered in two seasons—the long rains in the spring, and the short rains in the fall. Regional climate model projections suggest that the long rains will weaken under greenhouse gas forcing, and the short rains season will extend farther into the winter months. Observations indicate that the long rains are already weakening.Changes in seasonal rainfall over parts of subtropical southern Africa are observed, with repercussions and challenges for agriculture and water availability. Some elements of these observed changes are captured in model simulations of greenhouse gas-induced climate change, especially an early demise of the rainy season. The projected changes are quite regional, however, and more high-resolution study is needed. In addition, there has been very limited study of climate change in the Congo Basin and across northern Africa. Continued efforts to understand and predict climate using higher-resolution simulation must be sustained to better understand observed and projected changes in the physical processes that support African precipitation systems as well as the teleconnections that communicate remote forcings into the continent.
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Alharbi, Yousef, Manish S. Patankar, and Rebecca J. Whelan. Antibody-Based Therapy for Ovarian Cancer. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780190248208.003.0006.
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With their role in connecting disease-associated antigens to the cellular immune response, antibodies hold considerable promise as therapeutic agents. This chapter discusses three classes of therapeutic antibodies that have been developed for use in ovarian cancer therapy. The first includes antibodies selected against tumor-associated antigens such as MUC16/CA125, mesothelin, epithelial cell adhesion molecule, and folate receptor α. Antibodies in the second class target proteins such as CTLA-4 and PD1 that act as immune response checkpoint receptors. The third class of antibodies target secreted factors that promote tumor growth: targets in this class include vascular endothelial growth factor, cytokines, and chemokines. The development of each of these is described. The chapter also discusses the complications presented by soluble antigens, which serve to limit the applicability of antigens (such as MUC16/CA125) that are both cell-surface associated and circulating and the prospects for the combination of antibody-based immunotherapy and chemotherapy.
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Allen, Michael P., and Dominic J. Tildesley. Nonequilibrium molecular dynamics. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198803195.003.0011.
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This chapter explains some of the fundamental issues associated with applying perturbations to a molecular dynamics simulation, along with practical details of methods for studying systems out of equilibrium. The main emphasis is on fluid flow and viscosity measurements. Spatially homogeneous perturbations are described to study shear and extensional flow. Non-equilibrium methods are applied to the study of heat flow and the calculation of the thermal conductivity. Issues of thermostatting, and the modelling of surface-fluid interactions for inhomogeneous systems, are discussed. The measurement of free energy changes through non-equilibrium work expressions such as those of Jarzynski and Crooks is also explained.
Book chapters on the topic "Associated surface form"
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Tsang, S. T. Jerry, and A. Hamish R. W. Simpson. "Pathogenesis of Biomaterial-Associated Infection." In Racing for the Surface, 109–69. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-34475-7_6.
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Bai, Dan, Jingjie Chen, Peng Li, and Wei Huang. "Perspectives on Biomaterial-Associated Infection: Pathogenesis and Current Clinical Demands." In Racing for the Surface, 75–93. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-34475-7_4.
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McNab, Roderick, and Howard F. Jenkinson. "Lipoproteins and other cell-surface associated proteins in streptococci." In Methods for studying the genetics, molecular biology, physiology, and pathogenesis of the streptococci, 209–16. Dordrecht: Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-017-2258-2_23.
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Shilko, Evgeny V., Alexey Yu Smolin, Andrey V. Dimaki, and Galina M. Eremina. "Particle-Based Approach for Simulation of Nonlinear Material Behavior in Contact Zones." In Springer Tracts in Mechanical Engineering, 67–89. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-60124-9_4.
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AbstractMethods of particles are now recognized as an effective tool for numerical modeling of dynamic mechanical and coupled processes in solids and liquids. This chapter is devoted to a brief review of recent advances in the development of the popular particle-based discrete element method (DEM). DEM is conventionally considered as a highly specialized technique for modeling the flow of granular media and the fracture of brittle materials at micro- and mesoscopic scales. However, in the last decade, great progress has been made in the development of the formalism of this method. It is largely associated with the works of the scientific group of Professor S. G. Psakhie. The most important achievement of this group is a generalized formulation of the method of homogeneously deformable discrete elements. In the chapter, we describe keystones of this implementation of DEM and a universal approach that allows one to apply various rheological models of materials (including coupled models of porous fluid-saturated solids) to a discrete element. The new formalism makes possible qualitative expansion of the scope of application of the particle-based discrete element technique to materials with various rheological properties and to the range of considered scales form microscopic to macroscopic. The capabilities of this method are especially in demand in the study of the features of contact interaction of materials. To demonstrate these capabilities, we briefly review two recent applications concerning (a) the effect of adhesive interaction on the regime of wear of surface asperities under tangential contact of bodies and (b) the nonmonotonic dependence of the stress concentration in the neck of the human femur on the dynamics of hip joint contact loading.
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Schmidt, Michael G., Andrea L. Banks, and Cassandra D. Salgado. "Role of the Microbial Burden in the Acquisition and Control of Healthcare Associated Infections: The Utility of Solid Copper Surfaces." In Use of Biocidal Surfaces for Reduction of Healthcare Acquired Infections, 59–83. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-08057-4_4.
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Elahmer, O. R., M. W. Raza, M. M. Ogilvie, C. C. Blackwell, D. M. Weir, and R. A. Elton. "The Effect of Respiratory Virus Infection on Expression of Cell Surface Antigens Associated with Binding of Potentially Pathogenic Bacteria." In Toward Anti-Adhesion Therapy for Microbial Diseases, 169–77. Boston, MA: Springer US, 1996. http://dx.doi.org/10.1007/978-1-4613-0415-9_19.
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Lewis, Cara L. "Plastic Form." In Dynamic Form, 18–52. Cornell University Press, 2020. http://dx.doi.org/10.7591/cornell/9781501749179.003.0002.
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This chapter discusses Henry James's The Golden Bowl (1904). It shows how James's sculptural aesthetics, elaborated through a series of ornate metaphors, encompasses not only sculptural objects but also the viewing practices and temporalities associated with sculpture. Such viewing in the round, with its frequent retreading of old ground, creates the surface texture of James's, at times, almost impenetrable prose. Viewing in the round also activates a narrative temporality that renders the novel as a dynamic form to be processed over time, revisited, and reviewed. The Golden Bowl thus helps one to see that novelistic engagement with the fine arts does not produce self-contained, static, spatial form. Instead, shifts in perspective and point of view as James's characters circle sculptural objects—and as readers make their way around the novel—reinvent the novel as an experiment in plastic form.
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Sposito, Garrison. "Soil Particle Surface Charge." In The Chemistry of Soils. Oxford University Press, 2016. http://dx.doi.org/10.1093/oso/9780190630881.003.0011.
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Structural charge arises on the surfaces of soil mineral particles in which either cation vacancies or isomorphic substitutions of cations by cations of lower valence occur. The principal minerals bearing structural charge are therefore the micas (Section 2.2), the 2:1 clay minerals (Section 2.3), or the Mn(IV) oxide, birnessite (Section 2.4). These three classes of mineral are all layer type and the cleavage surface on which their structural charge is manifest is a plane of O ions. The plane of O ions on the cleavage surface of a layer-type aluminosilicate is called a siloxane surface.This plane is characterized by hexagonal symmetry in the configuration of its constituent O ions, as shown at the top of Fig. 2.3 and, more explicitly, on the right side of Fig. 2.4, where a portion of the siloxane surface of the micas is depicted. Reactive molecular units on the surfaces of soil particles are termed surface functional groups. The functional group associated with the siloxane surface is the roughly hexagonal (strictly speaking, ditrigonalbecause the hexagonal symmetry is distorted when the tetrahedral sheet is fused to an octahedral sheet to form a layer) cavity formed by six corner-sharing silica tetrahedra. This cavity has a diameter of about 0.26 nm. The reactivity of the siloxane cavity depends on the nature of the electronic charge distribution in the layer structure. If there are no nearby isomorphic cations substitutions to create a negative charge, the O ions bordering the siloxane cavity function as an electron cloud donor that can bind molecules weakly through the van der Waals interaction. These interactions are akin to those underlying the hydrophobic interaction, discussed in Section 3.5, because the O in the siloxane surface can form only very weak hydrogen bonds with water molecules. Therefore, uncharged patches on siloxane surfaces may be considered hydrophobic regions to a certain degree, with, accordingly, an attraction for hydrophobic organic molecules. However, if isomorphic substitution of Al3+ by either Fe2+ or Mg2+ occurs in the octahedral sheet, the resulting structural charge is manifest on the siloxane cavities, as discussed in Section 2.3.
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Atkinson, Martin E. "The temporomandibular joints, muscles of mastication, and the infratemporal and pterygopalatine fossae." In Anatomy for Dental Students. Oxford University Press, 2013. http://dx.doi.org/10.1093/oso/9780199234462.003.0033.
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It is essential that dental students and practitioners understand the structure and function of the temporomandibular joints and the muscles of mastication and other muscle groups that move them. The infratemporal fossa and pterygopalatine fossa are deep to the mandible and its related muscles; many of the nerves and blood vessels supplying the structures of the mouth run through or close to these areas, therefore, knowledge of the anatomy of these regions and their contents is essential for understanding the dental region. The temporomandibular joints (TMJ) are the only freely movable articulations in the skull together with the joints between the ossicles of the middle ear; they are all synovial joints. The muscles of mastication move the TMJ and the suprahyoid and infrahyoid muscles also play a significant role in jaw movements. The articular surfaces of the squamous temporal bone and of the condylar head (condyle) of the mandible form each temporomandibular joint. These surfaces have been briefly described in Chapter 22 on the skull and Figure 24.1A indicates their shape. The concave mandibular fossa is the posterior articulating surface of each squamous temporal bone and houses the mandibular condyle at rest. The condyle is translated forwards on to the convex articular eminence anterior to the mandibular fossa during jaw movements. The articular surfaces of temporomandibular joints are atypical; they covered by fibrocartilage (mostly collagen with some chondrocytes) instead of hyaline cartilage found in most other synovial joints. Figures 24.1B and 24.1C show the capsule and ligaments associated with the TMJ. The tough, fibrous capsule is attached above to the anterior lip of the squamotympanic fissure and to the squamous bone around the margin of the upper articular surface and below to the neck of the mandible a short distance below the limit of the lower articular surface. The capsule is slack between the articular disc and the squamous bone, but much tighter between the disc and the neck of the mandible. Part of the lateral pterygoid muscle is inserted into the anterior surface of the capsule. As in other synovial joints, the non-load-bearing internal surfaces of the joint are covered with synovial membrane.
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Saltzman, W. Mark. "Cell Adhesion." In Tissue Engineering. Oxford University Press, 2004. http://dx.doi.org/10.1093/oso/9780195141306.003.0011.
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The external surface of the cell consists of a phospholipid bilayer which carries a carbohydrate-rich coat called the glycocalyx; ionizable groups within the glycocalyx, such as sialic acid (N-acetyl neuraminate), contribute a net negative charge to the cell surface. Many of the carbohydrates that form the glycocalyx are bound to membrane-associated proteins. Each of these components— phospholipid bilayer, carbohydrate-rich coat, membrane-associated protein—has distinct physicochemical characteristics and is abundant. Plasma membranes contain ∼50% protein, ∼45% lipid, and ∼5% carbohydrate by weight. Therefore, each component influences cell interactions with the external environment in important ways. Cells can become attached to surfaces. The surface of interest may be geometrically complex (for example, the surface of another cell, a virus, a fiber, or an irregular object), but this chapter will focus on adhesion between a cell and a planar surface. The consequences of cell–cell adhesion are considered further in Chapter 8 (Cell Aggregation and Tissue Equivalents) and Chapter 9 (Tissue Barriers to Molecular and Cellular Transport). The consequences of cell–substrate adhesion are considered further in Chapter 7 (Cell Migration) and Chapter 12 (Cell Interactions with Polymers). Since the growth and function of many tissue-derived cells required attachment and spreading on a solid substrate, the events surrounding cell adhesion are fundamentally important. In addition, the strength of cell adhesion is an important determinant of the rate of cell migration, the kinetics of cell–cell aggregation, and the magnitude of tissue barriers to cell and molecule transport. Cell adhesion is therefore a major consideration in the development of methods and materials for cell delivery, tissue engineering, and tissue regeneration. The most stable and versatile mechanism for cell adhesion involves the specific association of cell surface glycoproteins, called receptors, and complementary molecules in the extracellular space, called ligands. Ligands may exist freely in the extracellular space, they may be associated with the extracellular matrix, or they may be attached to the surface of another cell. Cell–cell adhesion can occur by homophilic binding of identical receptors on different cells, by heterophilic binding of a receptor to a ligand expressed on the surface of a different cell, or by association of two receptors with an intermediate linker. Cell–matrix adhesion usually occurs by heterophilic binding of a receptor to a ligand attached to an insoluble element of the extracellular matrix.
Conference papers on the topic "Associated surface form"
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Hennessey, Michael P., Derek A. Olson, and Cheri Shakiban. "Steering Options for Maneuvering a Particle on a Surface." In ASME 2019 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/imece2019-10241.
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Abstract We consider the general problem of steering an infinitesimal propelled and steerable particle with no rotational inertia traversing on a mathematically smooth (vs. frictionless) surface, where both the speed and body yaw rate serve as inputs to the system and lateral motion is not allowed, i.e. through a no sideslip condition. More specifically, focus is on derivation of relevant state equations in control input form, numerical and visual confirmation of state equation accuracy through specific simulations, and exploring interesting approaches to nonholonomic path planning with associated numerical simulation and visualization. Given the state equations (3rd order), in the interests of practical validation, they were exercised by considering motion on a number of smooth surfaces. The surfaces were selected for a variety of reasons, such as: the resulting qualitative trajectory is known a priori, there exists an opportunity to check numerical results with respect to previous results, or the surfaces are iconic and/or are geometrically rich. Nonholonomic steering on the surface is a very interesting and challenging problem and several approaches are investigated: (1) steering using sinusoids (detailed), (2) steering on a trajectory, and (3) “drive-and-turn” (valid in this case). Prior to implementing the steering using sinusoids algorithm, it was necessary to transform the system into “one-chained” form. The first step entailed conversion to an approximate one-chained form model that possesses a certain structure, from which the process established by Murray and Sastry can be successfully launched, where two special smooth scalar functions of the states are sought that possess special relationships to Lie-related distribution spaces associated with the control input vectors. Inputs are then transformed as well via specialized Lie derivatives. It was demonstrated through simulation that steering to an arbitrary system state on a faceted surface can be accomplished with sinusoidal inputs in only one maneuver set (i.e. maneuver A & B). Using this fact, the work presented culminates with steering to an arbitrary system state on a smooth surface that can be accomplished by essentially iterating on a steering algorithm that assumes the particle is on a plane tangent to the smooth surface at the desired destination. In this regard, it is shown that a sequence of maneuver sets converges rather quickly in the example demonstrated. Applications of this work pertain to the fairly general situation of steering a vehicle on a smooth surface, a practical vehicle navigation and control problem.
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Loftus, Martin, and Da-Zhi Wang. "Surface Blemishes in 3D Offset Machining." In ASME 2004 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/detc2004-57763.
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High-speed machining (HSM) provides a new dimension to machining parts in hard steel because it eliminates intermediate processes and minimizes hand-finishing operations. Lead times and overall manufacturing costs are reduced, but the potential benefits can only be realized when the high-speed processes are implemented correctly. Successful high-speed applications depend on the linkage between contributing factors (machine tool, control system, tooling system, CAM system, CAM operator and machine operator) working effectively. A weakness in one of these areas can jeopardize the geometric form and surface quality in a high-speed operation. Such weaknesses can raise the paradox that as the quality of a machined part is improved through HSM, there is an increasing awareness of smaller defects. This is an acute problem in the final stages of the manufacture of dies, molds, and prototype components, where finished parts are rejected on their overall appearance, even though they satisfy all the standard design quality criteria. Very small, localized surface marks produced during machining operations are perceived as serious blemishes to the eye. One of the most obvious, and frequent surface blemishes are the marks associated with the popular 3D offset machining strategy. These marks are produced every time the 3D offset strategy is used and the parts have to be finished in a manual benching operation. This manual process is indeterminate in terms of time and cost. There is also a great risk that the geometric shapes and tolerances are compromised by the uncontrolled manual operations. This paper reports the results of a series of machining trials to assess the effect of the 3D offset strategy on machined parts, and it considers two modified offset strategies that were designed to alleviate the marking process.
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Kulkarni, S. S., and Sarika Sharma. "Optimization of Turning Parameter of Composite Materials Using Response Surface Method in Minitab." In National Conference on Relevance of Engineering and Science for Environment and Society. AIJR Publisher, 2021. http://dx.doi.org/10.21467/proceedings.118.1.
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This paper represents the optimization method utilized in machining process for figuring out the most advantageous manner design. Typically, the technique layout parameters in machining procedures are noticeably few turning parameters inclusive of reducing velocity, feed and depth. The optimization of speed, feed depth of cut is very tough because of several other elements associated with processing situations and form complexities like surface Roughness, material removal rate (MRR) that are based Parameters. On this task a new fabric glass fibre composite is introduced through which could lessen costing of manufacturing and time and additionally it will boom the technique of productiveness. Composite substances have strength, stiffness, light weight, which gives the large scope to engineering and technology. The proposed research work targets to analyze turning parameters of composite material. The machining parameters are very important in manufacturing industries. The present research work is optimized surface roughness of composite material specifically in turning procedure with the aid of changing parameter including intensity of reduce, slicing velocity and feed price and additionally expect the mechanical houses of composite material. The RSM optimization is important because it evaluates the effects of multiple factors and their interactions on one or more responsive variables. It is observed that the material removal rate increases and surface roughness decreases as per the increase of Spindle speed and feed rate.
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Retzler, C. H., R. C. T. Rainey, and J. R. Chaplin. "Non-Linear Run-Up on a Vertical Surface-Piercing Cylinder." In ASME 2004 23rd International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2004. http://dx.doi.org/10.1115/omae2004-51549.
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This paper presents and analyses results of experiments in which a vertical surface-piercing cylinder was driven with a horizontal motion a cos ωt in water initially at rest. Using a novel system of 112 water surface elevation gauges that were monitored almost simultaneously at high frequency, measurements were made of the run-up on the cylinder over a wide range of conditions. According to linear theory, the run-up is of the form a cos ωt cos θ. Non-linear components at temporal and spatial frequencies up to the 3rd harmonic were identified in the measurements, and in some of these, the coefficient of the leading term in a polynomial expansion in the amplitude of motion could be computed with reasonable confidence. Very successful comparisons are made with conventional linear potential theory. Some features of the free surface motion that are normally associated with higher order solutions were also computed from the first-order potential, and in some respects they were in good agreement with the measurements.
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Shi, Jinhua, Liwu Wei, and Poh-Sang Lam. "Flaw Stability Analysis of Semi-Elliptical Surface Cracks in Canisters Under the Influence of Welding Residual Stress." In ASME 2016 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/pvp2016-63887.
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Many stainless steel canisters for the dry storage of spent nuclear fuel are located in coastal regions. Because the heat treatment for relieving the welding residual stress is not required during fabrication, these canisters may be susceptible to chloride induced stress corrosion cracking due to the deliquescence of chloride-bearing marine salts or dust that enter the overpack system and deposit on the canister external surface. The NDE techniques and the associated delivery system are being developed to conduct periodic inservice inspections. The acceptance standards are needed to disposition findings should flaw-like indications be found. The instability crack lengths and depths for these flaws in the form of semi-elliptical shape near the welds are determined with R6 procedure. The cracks are subject to the canister design pressure and handling loads as well as the estimated welding residual stresses.
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Li, Han, and Brent C. Houchens. "Numerical Issues Associated With the Full-Zone Model of the Optically Heated Floating-Zone Used in Semiconductor Processing." In ASME 2008 Fluids Engineering Division Summer Meeting collocated with the Heat Transfer, Energy Sustainability, and 3rd Energy Nanotechnology Conferences. ASMEDC, 2008. http://dx.doi.org/10.1115/fedsm2008-55169.
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Recent models of the thermocapillary driven liquid bridge or full-zone (FZ) have highlighted numerical difficulties in the system, associated with the large velocity gradients near the free surface and the geometric singularity at r = 0. High resolution spectral solutions have been developed to account for these issues. These result in complex representations and highly specialized numerical procedures. After a brief review of these methods, a simplified formulation for the FZ model with strong form boundary conditions is proposed and discussed. Comparisons are made using base flows and stability analyses. Existing solutions have overcome the geometric singularity either by moving the grid away from the r = 0 axis, or by maintaining the correct Taylor series expansion in the representation of each dependent variable. The former has the weakness that an important constraint is not applied. The later formulation is rigorous, but results in complex expressions for the governing equations. To decrease the load associated with the mathematical manipulation and numerical implementation of this method, here a more general Chebyshev polynomial representation of the stream function is applied to the axisymmetric base flow. This removes the need to maintain the proper expansion and instead offers a set of equations in strong form by treating the axis as a boundary known from the spatial symmetry of the model. However, this does not guarantee that momentum is conserved at the internal symmetry boundaries. Various applications of the other boundary conditions are also studied. In the most accurate representation, all boundary conditions except the thermocapillary condition are cast in the strong form via orthogonality. These strong equations must be chosen carefully to avoid introducing redundant conditions. However, the result is a mathematically simpler representation that mimics the accuracy of previous methods.
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Choi, K. S., and J. Pan. "A Generalized Anisotropic Hardening Rule Based on the Mroz Multi-Yield-Surface Model." In ASME 2008 Pressure Vessels and Piping Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/pvp2008-61800.
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In this paper, a generalized anisotropic hardening rule based on the Mroz multi-yield-surface model is derived. The evolution equation for the active yield surface is obtained by considering the continuous expansion of the active yield surface during the unloading/reloading process. The incremental constitutive relation based on the associated flow rule is then derived for a general yield function. As a special case, detailed incremental constitutive relations are derived for the Mises yield function. The closed-form solutions for one-dimensional stress-plastic strain curves are also derived and plotted for the Mises materials under cyclic loading conditions. The stress-plastic strain curves show closed hysteresis loops under uniaxial cyclic loading conditions and the Masing hypothesis is applicable. A user material subroutine based on the Mises yield function, the anisotropic hardening rule and the constitutive relations was then written and implemented into ABAQUS. Computations were conducted for a simple plane strain finite element model under uniaxial monotonic and cyclic loading conditions based on the anisotropic hardening rule and the isotropic and nonlinear kinematic hardening rules of ABAQUS. The results indicate that the plastic response of the material follows the intended input stress-strain data for the anisotropic hardening rule whereas the plastic response depends upon the input strain ranges of the stress-strain data for the nonlinear kinematic hardening rule.
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Scott-Emuakpor, Onome, Tommy George, Emily Henry, Casey Holycross, and Jeff Brown. "As-Built Geometry and Surface Finish Effects on Fatigue and Tensile Properties of Laser Fused Titanium 6Al-4V." In ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/gt2017-63482.
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The as-built material behavior of additive manufactured (AM) Titanium (Ti) 6Al-4V is investigated in this study. A solution heat treated, aged, stress relieved, and hot isostatic pressed Laser Powder Bed Fusion (LPBF) AM process was used to manufacture the specimens of interest. The motivation behind this work is based on the ever-growing desire of aerospace system designers to use AM to fabricate components with novel geometries. Specifically, there is keen interest in AM components with complex internal cooling configurations such as turbine blades, nozzle vanes, and heat exchangers that can improve small scale propulsion performance. Though it is feasible to three-dimensionally print parts that meet the Fit portion of a part characteristic description and identification, the Form and Function portions have proven to be more difficult to conquer. This study addresses both the Form and Function characteristics of the LPBF AM process via the investigation of geometry variation and surface roughness effects pertaining to mechanical properties and fatigue behavior of Ti 6Al-4V. Results show that geometry variation may be the cause of increased vibration fatigue life uncertainty. Also, both fatigue and tensile properties show profound discrepancies associated with surface finish. As-built surface finish specimens have lower fatigue and ductility performance, but the results are more consistent than polished data.
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Pinson, Mark W., and Ting Wang. "Effect of Two-Scale Roughness on Boundary Layer Transition Over a Heated Flat Plate: Part 1 — Surface Heat Transfer." In ASME 1999 International Gas Turbine and Aeroengine Congress and Exhibition. American Society of Mechanical Engineers, 1999. http://dx.doi.org/10.1115/99-gt-158.
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An experimental study was conducted to investigate surface heat transfer and boundary layer development associated with flow over a flat test surface covered with two roughness scales. Two-scale roughness was used because in-service aeroengines commonly display larger roughness concentrated at the leading edge with smaller roughness distributed downstream. The first scale, covering up to the first 5 cm of the test surface, was in the form of a sandpaper strip, an aluminum strip, or a cylinder. The second roughness scale covered the remainder of the test surface (2 m) in the form of sandpaper or a smooth surface. In part 1, the surface heat transfer results are examined. Even though the roughness scales were hydraulically smooth, they induced significantly earlier transition onset, with the two-dimensional roughness causing earlier transition than three-dimensional roughness. All of the rough/smooth cases unexpectedly triggered earlier transition than rough/rough cases. This indicated that the scale of the step-change at the joint between two roughness scales was predominant over the downstream roughness on inducing early transition. Reducing the overall height of the step change was shown to have a greater effect on transition than the specific geometry of the roughness scale.
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Chen, Wei, Kwok-Leung Tsui, Janet K. Allen, and Farrokh Mistree. "Integration of the Response Surface Methodology With the Compromise Decision Support Problem in Developing a General Robust Design Procedure." In ASME 1995 Design Engineering Technical Conferences collocated with the ASME 1995 15th International Computers in Engineering Conference and the ASME 1995 9th Annual Engineering Database Symposium. American Society of Mechanical Engineers, 1995. http://dx.doi.org/10.1115/detc1995-0064.
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Abstract In this paper we introduce a comprehensive and rigorous robust design procedure to overcome some limitations of the current approaches. A comprehensive approach is general enough to model the two major types of robust design applications, namely, • robust design associated with the minimization of the deviation of performance caused by the deviation of noise factors (uncontrollable parameters), AND • robust design due to the minimization of the deviation of performance caused by the deviation of control factors (design variables). We achieve mathematical rigor by using, as a foundation, principles from the design of experiments and optimization. Specifically, we integrate the Response Surface Method (RSM) with the compromise Decision Support Problem (DSP). Our approach is especially useful for design problems where there are no closed-form solutions and system performance is computationally expensive to evaluate. The design of a solar powered irrigation system is used as an example. Our focus in this paper is on illustrating our approach rather than on the results per se.
Reports on the topic "Associated surface form"
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Wallach, Rony, Tammo Steenhuis, Ellen R. Graber, David DiCarlo, and Yves Parlange. Unstable Flow in Repellent and Sub-critically Repellent Soils: Theory and Management Implications. United States Department of Agriculture, November 2012. http://dx.doi.org/10.32747/2012.7592643.bard.
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Water repellency causes unstable wetting fronts that result in water moving in preferential flowpaths through homogeneous soils as well in structured soils where macropores enhance the preferential flow pattern. Water repellency is typically associated with extended water ponding on the soil surface, but we have found that repellency is important even before the water ponds. Preferential flow fingers can form under conditions where the contact angle is less than 90o, but greater than 0o. This means that even when the soil is considered wettable (i.e., immediate penetration of water), water distribution in the soil profile can be significantly non-uniform. Our work concentrated on various aspects of this subject, with an emphasis on visualizing water and colloid flow in soil, characterizing mathematically the important processes that affect water distribution, and defining the chemical components that are important for determining contact angle. Five papers have been published to date from this research, and there are a number of papers in various stages of preparation.
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NAVAL UNDERSEA WARFARE CENTER NEWPORT DIV RI. General Information for Surface Vessel Torpedo Tubes, Loading Trays, and Associated Equipment. Fort Belvoir, VA: Defense Technical Information Center, August 2000. http://dx.doi.org/10.21236/ada384573.
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Rumble, Mark A. Wildlife associated with scoria outcrops: implications for reclamation of surface-mined lands. Ft. Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station, 1989. http://dx.doi.org/10.2737/rm-rp-285.
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Harris, Aubrey E., Leslie Hopkinson, and Daniel Soeder. The Assessment of Instruments for Detecting Surface Water Spills Associated with Oil and Gas Operations. Office of Scientific and Technical Information (OSTI), December 2016. http://dx.doi.org/10.2172/1340657.
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Netzel, T. L. An exploration of sequence specific DNA-duplex/pyrene interactions for intercalated and surface-associated pyrene species. Technical progress report. Office of Scientific and Technical Information (OSTI), January 1994. http://dx.doi.org/10.2172/10145812.
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Husson, Scott M., Viatcheslav Freger, and Moshe Herzberg. Antimicrobial and fouling-resistant membranes for treatment of agricultural and municipal wastewater. United States Department of Agriculture, January 2013. http://dx.doi.org/10.32747/2013.7598151.bard.
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This research project introduced a novel membrane coating strategy to combat biofouling, which is a major problem for the membrane-based treatment of agricultural and municipal wastewaters. The novelty of the strategy is that the membrane coatings have the unique ability to switch reversibly between passive (antifouling) and active (antimicrobial) fouling control mechanisms. This dual-mode approach differs fundamentally from other coating strategies that rely solely on one mode of fouling control. The research project had two complementary objectives: (1) preparation, characterization, and testing of dual-mode polymer nanolayers on planar surfaces and (2) evaluation of these nanolayers as membrane modifiers. The first objective was designed to provide a fundamental understanding of how polymer nanolayer chemistry and structure affect bacterial deposition and to demonstrate the reversibility of chemical switching. The second objective, which focused on membrane development, characterization, and testing, was designed to demonstrate methods for the production of water treatment membranes that couple passive and active biofouling control mechanisms. Both objectives were attained through synergistic collaboration among the three research groups. Using planar silicon and glass surfaces, we demonstrated using infrared spectroscopy that this new polymer coating can switch reversibly between the anti-fouling, zwitterion mode and an anti-microbial, quaternary amine mode. We showed that switching could be done more than 50 times without loss of activity and that the kinetics for switching from a low fouling zwitterion surface to an antimicrobial quaternary amine surface is practical for use. While a low pH was required for switching in the original polymer, we illustrated that by slightly altering the chemistry, it is possible to adjust the pH at which the switching occurs. A method was developed for applying the new zwitterionic surface chemistry onto polyethersulfone (PES) ultrafiltration membranes. Bacteria deposition studies showed that the new chemistry performed better than other common anti-fouling chemistries. Biofilm studies showed that PESultrafiltration membranes coated with the new chemistry accumulated half the biomass volume as unmodified membranes. Biofilm studies also showed that PES membranes coated with the new chemistry in the anti-microbial mode attained higher biofilm mortality than PES membranes coated with a common, non-switchablezwitterionic polymer. Results from our research are expected to improve membrane performance for the purification of wastewaters prior to use in irrigation. Since reduction in flux due to biofouling is one of the largest costs associated with membrane processes in water treatment, using dual-mode nanolayer coatings that switch between passive and active control of biofouling and enable detachment of attached biofoulants would have significant economic and societal impacts. Specifically, this research program developed and tested advanced ultrafiltration membranes for the treatment of wastewaters. Such membranes could find use in membrane bioreactors treating municipal wastewater, a slightly upgraded version of what presently is used in Israel for irrigation. They also may find use for pretreatment of agricultural wastewaters, e.g., rendering facility wastewater, prior to reverse osmosis for desalination. The need to desalinate such impaired waters water for unlimited agricultural use is likely in the near future.
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Gillor, Osnat, Stefan Wuertz, Karen Shapiro, Nirit Bernstein, Woutrina Miller, Patricia Conrad, and Moshe Herzberg. Science-Based Monitoring for Produce Safety: Comparing Indicators and Pathogens in Water, Soil, and Crops. United States Department of Agriculture, May 2013. http://dx.doi.org/10.32747/2013.7613884.bard.
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Using treated wastewater (TWW) for crop irrigation represents an important opportunity for ensuring adequate food production in light of growing freshwater scarcity worldwide. However, the environmentally sustainable approach of using TWW for irrigation can lead to contamination of produce with fecal pathogens that may remain in treated water. The overall goal of this research was to evaluate the correlation between the presence of fecal indicator bacteria (FIB) and that of a suite of human pathogens in TWW, the irrigated soil, and crops. Field experiments were conducted to compare secondary and tertiary TWW with dechlorinated tap water for irrigation of tomatoes, a typical commercial crop, in Israel, a semi-arid country. Human pathogens including bacteria (Salmonella), protozoa (Cryptosporidiumand Giardia), and viruses (Adenovirus [AV Types A, B, C & 40/41] and Enterovirus [EV71 subtypes]) were monitored in two field trials using a combination of microscopic, cultivation-based, and molecular (qPCR) techniques. Results from the field trials indicate that microbial contamination on the surface of tomatoes did not appear to be associated with the source of irrigated waters; FIB contamination was not statistically different on tomatoes irrigated with TWW as compared to tomatoes irrigated with potable water. In fact, Indicator bacteria testing did not predict the presence of pathogens in any of the matrices tested. High concentrations of FIB were detected in water and on tomato surfaces from all irrigation treatment schemes, while pathogen contamination on tomato surfaces (Cryptosporidiumand Salmonella) was only detected on crops irrigated with TWW. These results suggest that regular monitoring for pathogens should take place to accurately detect presence of harmful microorganisms that could threaten consumer safety. A notable result from our study is that the large numbers of FIB in the water did not appear to lead to FIB accumulation in the soil. With the exception of two samples, E. coli that was present at 10³ to 10⁴ cells/100 mL in the water, was not detected in the soil. Other bacterial targets associated with the enteric environment (e. g., Proteusspp.) as well as protozoal pathogens were detected in the TWW, but not in the soil. These findings suggest that significant microbial transfer to the soil from TWW did not occur in this study. The pattern of FIB contamination on the surfaces of tomatoes was the same for all treatment types, and showed a temporal effect with more contamination detected as the duration of the field trial increased. An important observation revealed that water quality dramatically deteriorated between the time of its release from the wastewater treatment plant and the time it was utilized for irrigation, highlighting the importance of performing water quality testing throughout the growing season at the cultivation site.
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May, David, David Biedenharn, Tate McAlpin, and Ty Wamsley. Hydraulic dike effects investigation on the Mississippi River : Natchez to Baton Rouge. Engineer Research and Development Center (U.S.), May 2021. http://dx.doi.org/10.21079/11681/40539.
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This report documents an investigation of the hydraulic effects of dikes on water levels in the Mississippi River between Natchez, MS, and Baton Rouge, LA, conducted for the U.S. Army Corps of Engineers, Mississippi Valley Division, Vicksburg, MS. The investigation was conducted using a previously calibrated Natchez-to-Baton Rouge Adaptive Hydraulics numerical model. The objectives were to alter roughness and height variables associated with the dikes and overbanks encompassed in the numerical model and evaluate their effects on water surface elevations. This academic exercise provides an indication of the relative level of impact associated with modifications to the dikes and overbanks for this portion of the Mississippi River and does not represent future plans or recommendations by the U.S. Army Corps of Engineers. Steady flow simulations were simulated for 12 May 2011 to investigate the variation in model results during the peak of the 2011 flood on the Mississippi River.
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Russo, David, Daniel M. Tartakovsky, and Shlomo P. Neuman. Development of Predictive Tools for Contaminant Transport through Variably-Saturated Heterogeneous Composite Porous Formations. United States Department of Agriculture, December 2012. http://dx.doi.org/10.32747/2012.7592658.bard.
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The vadose (unsaturated) zone forms a major hydrologic link between the ground surface and underlying aquifers. To understand properly its role in protecting groundwater from near surface sources of contamination, one must be able to analyze quantitatively water flow and contaminant transport in variably saturated subsurface environments that are highly heterogeneous, often consisting of multiple geologic units and/or high and/or low permeability inclusions. The specific objectives of this research were: (i) to develop efficient and accurate tools for probabilistic delineation of dominant geologic features comprising the vadose zone; (ii) to develop a complementary set of data analysis tools for discerning the fractal properties of hydraulic and transport parameters of highly heterogeneous vadose zone; (iii) to develop and test the associated computational methods for probabilistic analysis of flow and transport in highly heterogeneous subsurface environments; and (iv) to apply the computational framework to design an “optimal” observation network for monitoring and forecasting the fate and migration of contaminant plumes originating from agricultural activities. During the course of the project, we modified the third objective to include additional computational method, based on the notion that the heterogeneous formation can be considered as a mixture of populations of differing spatial structures. Regarding uncertainly analysis, going beyond approaches based on mean and variance of system states, we succeeded to develop probability density function (PDF) solutions enabling one to evaluate probabilities of rare events, required for probabilistic risk assessment. In addition, we developed reduced complexity models for the probabilistic forecasting of infiltration rates in heterogeneous soils during surface runoff and/or flooding events Regarding flow and transport in variably saturated, spatially heterogeneous formations associated with fine- and coarse-textured embedded soils (FTES- and CTES-formations, respectively).We succeeded to develop first-order and numerical frameworks for flow and transport in three-dimensional (3-D), variably saturated, bimodal, heterogeneous formations, with single and dual porosity, respectively. Regarding the sampling problem defined as, how many sampling points are needed, and where to locate them spatially in the horizontal x₂x₃ plane of the field. Based on our computational framework, we succeeded to develop and demonstrate a methdology that might improve considerably our ability to describe quntitaively the response of complicated 3-D flow systems. The results of the project are of theoretical and practical importance; they provided a rigorous framework to modeling water flow and solute transport in a realistic, highly heterogeneous, composite flow system with uncertain properties under-specified by data. Specifically, they: (i) enhanced fundamental understanding of the basic mechanisms of field-scale flow and transport in near-surface geological formations under realistic flow scenarios, (ii) provided a means to assess the ability of existing flow and transport models to handle realistic flow conditions, and (iii) provided a means to assess quantitatively the threats posed to groundwater by contamination from agricultural sources.
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Netzel, T. L. An exploration of sequence specific DNA-duplex/pyrene interactions for intercalated and surface-associated pyrene species. Final report, May 1, 1993--December 31, 1996. Office of Scientific and Technical Information (OSTI), March 1997. http://dx.doi.org/10.2172/548674.
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